Pacificorp (PPWLM) 10-K 26 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 16, 2018	Jun. 30, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Entity Registrant Name	BERKSHIRE HATHAWAY ENERGY CO
Entity Central Index Key	1,081,316
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		77,174,325
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 0
PacifiCorp [Member]
Document Information [Line Items]
Entity Registrant Name	PACIFICORP /OR/
Entity Central Index Key	75,594
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		357,060,915
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			0
MidAmerican Funding, LLC and Subsidiaries [Domain]
Document Information [Line Items]
Entity Registrant Name	MIDAMERICAN FUNDING, LLC
Entity Central Index Key	1,098,296
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	Yes
Entity Current Reporting Status	No
Entity Public Float			0
MidAmerican Energy Company and Subsidiaries [Member]
Document Information [Line Items]
Entity Registrant Name	MIDAMERICAN ENERGY COMPANY
Entity Central Index Key	928,576
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		70,980,203
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			0
Nevada Power Company [Member]
Document Information [Line Items]
Entity Registrant Name	NEVADA POWER COMPANY
Entity Central Index Key	71,180
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		1,000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			0
Sierra Pacific Power Company [Member]
Document Information [Line Items]
Entity Registrant Name	SIERRA PACIFIC POWER COMPANY
Entity Central Index Key	90,144
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		1,000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Liabilities, Net		$ 8,242	$ 13,879
Regulatory Liabilities		7,511	3,120
Current assets:
Cash and cash equivalents		935	721
Restricted Cash and Investments, Current		327	211
Trade receivables, net		2,014	1,751
Income taxes receivable		334	0
Inventories
Fuel		352	402
Inventories		888	925
Mortgage loans held for sale		465	359
Regulatory assets		189	150
Other current assets		815	706
Total current assets		5,778	4,673
Property, plant and equipment, net		65,871	62,509
Goodwill		9,678	9,010
Regulatory assets		2,761	4,307
Investments and restricted cash and investments		4,872	3,945
Other assets		1,248	996
Total assets		90,208	85,440
Current liabilities:
Accounts payable		1,519	1,317
Accrued interest		488	454
Accrued property, income and other taxes		354	389
Accrued employee expenses		274	261
Regulatory liabilities		202	187
Short-term debt	[1]	4,488	1,869
Current portion of long-term debt		3,431	1,006
Other current liabilities		1,049	1,017
Total current liabilities		11,603	6,313
BHE senior debt		5,452	7,418
Regulatory liabilities		7,309	2,933
BHE junior subordinated debentures		100	944
Subsidiary debt		26,210	26,748
Deferred income taxes		8,242	13,879
Other long-term liabilities		2,984	2,742
Asset Retirement Obligations, Noncurrent		894	856
Total liabilities		61,900	60,977
Commitments and contingencies
Shareholders' equity:
Common stock		0	0
Additional paid-in capital		6,368	6,390
Retained earnings		22,206	19,448
Accumulated other comprehensive loss, net		(398)	(1,511)
Total shareholders' equity		28,176	24,327
Noncontrolling interests		132	136
Total equity		28,308	24,463
Total liabilities and equity		90,208	85,440
Sierra Pacific Power Company [Member]
Deferred Tax Liabilities, Net		330	617
Regulatory Liabilities		500	290
Current assets:
Cash and cash equivalents		4	55
Trade receivables, net		112	117
Inventories
Fuel		7	9
Inventories		49	45
Regulatory assets		32	25
Other current assets		17	13
Total current assets		214	255
Public Utilities, Property, Plant and Equipment, Net		2,892	2,822
Regulatory assets		300	410
Other assets		7	6
Total assets		3,413	3,493
Current liabilities:
Accounts payable		92	146
Accrued interest		14	14
Accrued property, income and other taxes		10	10
Regulatory liabilities		19	69
Long-term Debt and Capital and Financial Lease Obligations, Current		2	1
Customer Deposits, Current		15	16
Other current liabilities		12	12
Total current liabilities		164	268
Regulatory liabilities		481	221
Long-term Debt and Capital and Financial Lease Obligations		1,152	1,152
Deferred income taxes		330	617
Other long-term liabilities		114	127
Asset Retirement Obligations, Noncurrent		10	10
Total liabilities		2,241	2,385
Shareholders' equity:
Common stock		0	0
Additional paid-in capital		1,111	1,111
Retained earnings		62	(2)
Accumulated other comprehensive loss, net		(1)	(1)
Total shareholders' equity		1,172	1,108
Total liabilities and equity		3,413	3,493
PacifiCorp [Member]
Deferred Tax Liabilities, Net		2,582	4,880
Regulatory Liabilities		3,071	1,032
Current assets:
Cash and cash equivalents		14	17
Trade receivables, net		684	728
Income taxes receivable		59	17
Inventories
Materials and supplies		235	228
Fuel		198	215
Inventories		433	443
Regulatory assets		31	53
Prepaid Expense, Current		73	64
Other current assets		21	32
Total current assets		1,315	1,354
Public Utilities, Property, Plant and Equipment, Net		19,203	19,162
Regulatory assets		1,030	1,490
Other assets		372	388
Total assets		21,920	22,394
Current liabilities:
Accounts payable		453	408
Accrued interest		115	115
Accrued property, income and other taxes		66	63
Accrued employee expenses		70	67
Regulatory liabilities		75	54
Short-term debt		80	270
Current portion of long-term debt and capital lease obligations		588	58
Other current liabilities		170	164
Total current liabilities		1,617	1,199
Regulatory liabilities		2,996	978
Long-term debt and capital lease obligations		6,437	7,021
Deferred income taxes		2,582	4,880
Other long-term liabilities		733	926
Asset Retirement Obligations, Noncurrent		190	194
Total liabilities		14,365	15,004
Commitments and contingencies
Shareholders' equity:
Preferred stock		2	2
Common stock		0	0
Additional paid-in capital		4,479	4,479
Retained earnings		3,089	2,921
Accumulated other comprehensive loss, net		(15)	(12)
Total shareholders' equity		7,555	7,390
Total liabilities and equity		21,920	22,394
MidAmerican Energy Company [Member]
Deferred Tax Liabilities, Net		2,237	3,572
Current assets:
Cash and cash equivalents		172	14
Receivables, Net, Current		344	285
Income taxes receivable		51	9
Inventories
Inventories		245	264
Other current assets		134	35
Total current assets		946	607
Public Utilities, Property, Plant and Equipment, Net		14,207	12,821
Regulatory assets		204	1,161
Investments and restricted cash and investments		728	653
Other assets		233	217
Total assets		16,318	15,459
Current liabilities:
Accounts payable		452	303
Accrued interest		48	45
Accrued property, income and other taxes		132	137
Short-term debt		0	99
Current portion of long-term debt and capital lease obligations		350	250
Other current liabilities		128	159
Total current liabilities		1,110	993
Regulatory liabilities		1,661	883
Long-term debt and capital lease obligations		4,692	4,051
Deferred income taxes		2,237	3,572
Other long-term liabilities		326	290
Asset Retirement Obligations, Noncurrent		528	510
Total liabilities		10,554	10,299
Commitments and contingencies
Shareholders' equity:
Common stock		0	0
Additional paid-in capital		561	561
Retained earnings		5,203	4,599
Total shareholders' equity		5,764	5,160
Total liabilities and equity		16,318	15,459
MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Liabilities, Net		2,235	3,568
Current assets:
Cash and cash equivalents		172	15
Receivables, Net, Current		348	287
Income taxes receivable		64	9
Inventories
Inventories		245	264
Other current assets		134	35
Total current assets		963	610
Property, plant and equipment, net		14,221	12,835
Goodwill		1,270	1,270
Regulatory assets		204	1,161
Investments and restricted cash and investments		730	655
Other assets		233	216
Total assets		17,621	16,747
Current liabilities:
Accounts payable		451	302
Accrued interest		53	52
Accrued property, income and other taxes		133	138
Notes Payable, Related Parties, Current		164	31
Short-term debt		0	99
Current portion of long-term debt and capital lease obligations		350	250
Other current liabilities		128	160
Total current liabilities		1,279	1,032
Regulatory liabilities		1,661	883
Long-term debt and capital lease obligations		4,932	4,377
Deferred income taxes		2,235	3,568
Other long-term liabilities		326	291
Asset Retirement Obligations, Noncurrent		528	510
Total liabilities		10,961	10,661
Commitments and contingencies
Shareholders' equity:
Additional paid-in capital		1,679	1,679
Retained earnings		4,981	4,407
Total shareholders' equity		6,660	6,086
Total liabilities and equity		17,621	16,747
Nevada Power Company [Member]
Deferred Tax Liabilities, Net		767	1,474
Regulatory Liabilities		1,121	453
Current assets:
Cash and cash equivalents		57	279
Trade receivables, net		238	243
Inventories
Fuel		3	13
Inventories		59	73
Regulatory assets		28	20
Other current assets		44	38
Total current assets		426	653
Public Utilities, Property, Plant and Equipment, Net		6,877	6,997
Regulatory assets		941	1,000
Other assets		35	39
Total assets		8,279	8,689
Current liabilities:
Accounts payable		156	187
Accrued interest		50	50
Accrued property, income and other taxes		63	93
Regulatory liabilities		91	37
Long-term Debt and Capital and Financial Lease Obligations, Current		842	17
Customer Deposits, Current		73	78
Other current liabilities		16	39
Total current liabilities		1,291	501
Regulatory liabilities		1,030	416
Long-term Debt and Capital and Financial Lease Obligations		2,233	3,049
Deferred income taxes		767	1,474
Other long-term liabilities		280	277
Asset Retirement Obligations, Noncurrent		76	63
Total liabilities		5,601	5,717
Shareholders' equity:
Common stock		0	0
Additional paid-in capital		2,308	2,308
Retained earnings		374	667
Accumulated other comprehensive loss, net		(4)	(3)
Total shareholders' equity		2,678	2,972
Total liabilities and equity		8,279	8,689
Parent Company [Member]
Current assets:
Cash and cash equivalents		346	33
Trade receivables, net		0	21
Inventories
Other current assets		21	2
Total current assets		818	161
Goodwill		1,221	1,221
Other assets		1,155	1,171
Total assets		39,330	37,291
Current liabilities:
Notes Payable, Related Parties, Current		182	194
Short-term debt		3,331	834
Total current liabilities		4,781	1,785
BHE senior debt		5,452	7,418
BHE junior subordinated debentures		100	944
Notes payable - affiliate		1	1,859
Other long-term liabilities		800	942
Total liabilities		11,134	12,948
Shareholders' equity:
Common stock		0	0
Additional paid-in capital		6,368	6,390
Retained earnings		22,206	19,448
Accumulated other comprehensive loss, net		(398)	(1,511)
Total shareholders' equity		28,176	24,327
Noncontrolling interests		20	16
Total equity		28,196	24,343
Total liabilities and equity		39,330	37,291
Deferred Income Taxes [Member]
Regulatory Liabilities	[2]	4,143	25
Deferred Income Taxes [Member] | PacifiCorp [Member]
Regulatory Liabilities		1,960	9
Deferred Income Taxes [Member] | MidAmerican Energy Company [Member]
Current liabilities:
Regulatory liabilities	[3]	681	0
Deferred Income Taxes [Member] | Nevada Power Company [Member]
Regulatory Liabilities	[4]	$ 670	$ 9
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[3]	(3)Amount predominantly represents the excess of nuclear decommission trust assets over the related asset retirement obligation. Refer to Note 12 for a discussion of asset retirement obligations.
[4]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Shareholders' equity:
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	115,000,000	115,000,000
Common stock, shares issued	77,000,000	77,000,000
Common stock, shares outstanding	77,000,000	77,000,000
PacifiCorp [Member]
Shareholders' equity:
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	357,000,000	357,000,000
Common stock, shares outstanding	357,000,000	357,000,000
Nevada Power Company [Member]
Shareholders' equity:
Common Stock, Par or Stated Value Per Share	$ 1	$ 1
Common stock, shares authorized	1,000	1,000
Common stock, shares issued	1,000	1,000
Common stock, shares outstanding	1,000	1,000
Sierra Pacific Power Company [Member]
Shareholders' equity:
Common Stock, Par or Stated Value Per Share	$ 3.75	$ 3.75
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	1,000	1,000
Common stock, shares outstanding	1,000	1,000
Common Stock [Member]
Shareholders' equity:
Common stock, shares outstanding	77,000,000	77,000,000
Common Stock [Member] | MidAmerican Energy Company [Member]
Shareholders' equity:
Common Stock, Par or Stated Value Per Share	$ 0	$ 0
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	70,980,203	70,980,203
Common stock, shares outstanding	70,980,203	70,980,203
Common Stock [Member] | Nevada Power Company [Member]
Shareholders' equity:
Common stock, shares outstanding	1,000	1,000
Common Stock [Member] | Sierra Pacific Power Company [Member]
Shareholders' equity:
Common stock, shares outstanding	1,000	1,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating revenue:
Energy	$ 15,171	$ 14,621	$ 15,354
Real estate	3,443	2,801	2,526
Total operating revenue	18,614	17,422	17,880
Energy:
Cost of sales	4,518	4,315	5,079
Operating expense	3,773	3,707	3,732
Depreciation and amortization	2,580	2,560	2,399
Real estate	3,229	2,589	2,342
Total operating costs and expenses	14,100	13,171	13,552
Operating income	4,514	4,251	4,328
Other income (expense):
Interest expense	(1,841)	(1,854)	(1,904)
Capitalized interest and allowance for borrowed funds	45	139	74
Allowance for equity funds	76	158	91
Other Interest and Dividend Income	111	120	107
Other, net	(398)	36	39
Total other income (expense)	(2,007)	(1,401)	(1,593)
Income before income tax (benefit) expense and equity (loss) income	2,507	2,850	2,735
Income tax (benefit) expense	(554)	403	450
Equity income (loss)	(151)	123	115
Net income	2,910	2,570	2,400
Net income attributable to noncontrolling interests	40	28	30
Net income (loss) attributable to parent	2,870	2,542	2,370
PacifiCorp [Member]
Operating revenue:
Electric Domestic Regulated Revenue	5,237	5,201	5,232
Energy:
Energy costs	1,770	1,751	1,868
Operations and maintenance	1,012	1,064	1,082
Utilities Operating Expense, Depreciation and Amortization	796	770	757
Taxes, other than income taxes	197	190	185
Total operating costs and expenses	3,775	3,775	3,892
Operating income	1,462	1,426	1,340
Other income (expense):
Interest expense	(381)	(380)	(379)
Capitalized interest and allowance for borrowed funds	11	15	18
Allowance for equity funds	20	27	33
Other, net	16	15	11
Total other income (expense)	(334)	(323)	(317)
Income before income tax (benefit) expense and equity (loss) income	1,128	1,103	1,023
Income tax (benefit) expense	360	340	328
Net income (loss) attributable to parent	768	763	695
MidAmerican Energy Company [Member]
Operating revenue:
Electric Domestic Regulated Revenue	2,108	1,985	1,837
Gas Domestic Regulated Revenue and Other	729	640	665
Total operating revenue	2,837	2,625	2,502
Energy:
Energy costs	434	409	433
Cost of natural gas purchases and other	442	367	398
Operations and maintenance	781	693	705
Utilities Operating Expense, Depreciation and Amortization	500	479	407
Taxes, other than income taxes	119	112	110
Total operating costs and expenses	2,276	2,060	2,053
Operating income	561	565	449
Other income (expense):
Interest expense	(214)	(196)	(183)
Capitalized interest and allowance for borrowed funds	15	8	8
Allowance for equity funds	41	19	20
Other, net	19	14	5
Total other income (expense)	(139)	(155)	(150)
Income before income tax (benefit) expense and equity (loss) income	422	410	299
Income tax (benefit) expense	(183)	(132)	(147)
Net income	605	542	446
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	0	0	22
Discontinued Operation, Tax Effect of Discontinued Operation	0	0	6
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	0	16
Net income (loss) attributable to parent	605	542	462
MidAmerican Funding, LLC and Subsidiaries [Domain]
Operating revenue:
Electric Domestic Regulated Revenue	2,108	1,985	1,837
Gas Domestic Regulated Revenue and Other	738	646	678
Total operating revenue	2,846	2,631	2,515
Energy:
Energy costs	434	409	433
Cost of natural gas purchases and other	447	371	407
Operations and maintenance	784	694	707
Utilities Operating Expense, Depreciation and Amortization	500	479	407
Taxes, other than income taxes	119	112	110
Total operating costs and expenses	2,284	2,065	2,064
Operating income	562	566	451
Other income (expense):
Interest expense	(237)	(219)	(206)
Capitalized interest and allowance for borrowed funds	15	8	8
Allowance for equity funds	41	19	20
Other, net	(9)	19	19
Total other income (expense)	(190)	(173)	(159)
Income before income tax (benefit) expense and equity (loss) income	372	393	292
Income tax (benefit) expense	(202)	(139)	(150)
Net income	574	532	442
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	0	0	22
Discontinued Operation, Tax Effect of Discontinued Operation	0	0	6
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	0	16
Net income (loss) attributable to parent	574	532	458
Nevada Power Company [Member]
Operating revenue:
Total operating revenue	2,206	2,083	2,402
Energy:
Cost of sales	902	768	1,084
Operations and maintenance	393	394	372
Utilities Operating Expense, Depreciation and Amortization	308	303	297
Taxes, other than income taxes	40	38	36
Total operating costs and expenses	1,643	1,503	1,789
Operating income	563	580	613
Other income (expense):
Interest expense	(179)	(185)	(190)
Capitalized interest and allowance for borrowed funds	1	4	3
Allowance for equity funds	1	2	4
Other, net	25	24	20
Total other income (expense)	(152)	(155)	(163)
Income before income tax (benefit) expense and equity (loss) income	411	425	450
Income tax (benefit) expense	156	146	162
Net income (loss) attributable to parent	255	279	288
Sierra Pacific Power Company [Member]
Operating revenue:
Electric Domestic Regulated Revenue	713	702	810
Gas Domestic Regulated Revenue	99	110	137
Total operating revenue	812	812	947
Energy:
Cost of sales	268	265	374
Cost of Purchased Oil and Gas	42	55	84
Operations and maintenance	166	170	167
Utilities Operating Expense, Depreciation and Amortization	114	118	113
Taxes, other than income taxes	24	24	25
Total operating costs and expenses	614	632	763
Operating income	198	180	184
Other income (expense):
Interest expense	(43)	(54)	(61)
Capitalized interest and allowance for borrowed funds	2	4	2
Allowance for equity funds	3	(1)	2
Other, net	4	4	3
Total other income (expense)	(34)	(47)	(54)
Income before income tax (benefit) expense and equity (loss) income	164	133	130
Income tax (benefit) expense	55	49	47
Net income (loss) attributable to parent	$ 109	$ 84	$ 83

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 2,910	$ 2,570	$ 2,400
Net income (loss) attributable to parent	2,870	2,542	2,370
Other comprehensive income (loss), net of tax:
Unrecognized amounts on retirement benefits, net of tax	64	(9)	52
Foreign currency translation adjustment	546	(583)	(680)
Unrealized gains (losses) on available-for-sale securities, net of tax	500	(30)	225
Unrealized (losses) gains on cash flow hedges, net of tax	3	19	(11)
Total other comprehensive income (loss), net of tax	1,113	(603)	(414)
Comprehensive income	4,023	1,967	1,986
Comprehensive income attributable to noncontrolling interests	40	28	30
Comprehensive income attributable to shareholders	3,983	1,939	1,956
Parent Company [Member]
Net income	2,873	2,545	2,373
Net income (loss) attributable to parent	2,870	2,542	2,370
Other comprehensive income (loss), net of tax:
Total other comprehensive income (loss), net of tax	1,113	(603)	(414)
Comprehensive income	3,986	1,942	1,959
Comprehensive income attributable to noncontrolling interests	3	3	3
Comprehensive income attributable to shareholders	3,983	1,939	1,956
Nevada Power Company [Member]
Net income (loss) attributable to parent	255	279	288
PacifiCorp [Member]
Net income (loss) attributable to parent	768	763	695
Other comprehensive income (loss), net of tax:
Unrecognized amounts on retirement benefits, net of tax	(3)	(1)	2
Total other comprehensive income (loss), net of tax	(3)	(1)	2
Comprehensive income attributable to shareholders	765	762	697
MidAmerican Energy Company [Member]
Net income (loss) attributable to parent	605	542	462
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on available-for-sale securities, net of tax	0	3	0
Unrealized (losses) gains on cash flow hedges, net of tax	0	0	(7)
Total other comprehensive income (loss), net of tax	0	3	(7)
Comprehensive income attributable to shareholders	605	545	455
MidAmerican Funding, LLC and Subsidiaries [Domain]
Net income (loss) attributable to parent	574	532	458
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on available-for-sale securities, net of tax	0	3	0
Unrealized (losses) gains on cash flow hedges, net of tax	0	0	(7)
Total other comprehensive income (loss), net of tax	0	3	(7)
Comprehensive income attributable to shareholders	$ 574	$ 535	$ 451

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income tax effect - unrecognized amounts on retirement benefits	$ 9	$ 11	$ 17
Income tax effect - unrealized gains (losses) on available-for-sale securities	270	(19)	129
Income tax effect - unrealized (losses) gains on cash flow hedges	(7)	13	(7)
MidAmerican Funding, LLC and Subsidiaries [Domain]
Income tax effect - unrealized gains (losses) on available-for-sale securities	0	1	0
Income tax effect - unrealized (losses) gains on cash flow hedges	0	0	(4)
MidAmerican Energy Company [Member]
Income tax effect - unrealized gains (losses) on available-for-sale securities	0	1	0
Income tax effect - unrealized (losses) gains on cash flow hedges	0	0	(4)
PacifiCorp [Member]
Income tax effect - unrecognized amounts on retirement benefits	$ 0	$ 0	$ (1)

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	PacifiCorp [Member]	PacifiCorp [Member]Preferred Stock [Member]	PacifiCorp [Member]Common Stock [Member]	PacifiCorp [Member]Additional Paid-in Capital [Member]	PacifiCorp [Member]Retained Earnings [Member]	PacifiCorp [Member]Accumulated Other Comprehensive Income (Loss) [Member]	MidAmerican Energy Company [Member]	MidAmerican Energy Company [Member]Common Stock [Member]	MidAmerican Energy Company [Member]Retained Earnings [Member]	MidAmerican Energy Company [Member]Accumulated Other Comprehensive Income (Loss) [Member]	MidAmerican Funding, LLC and Subsidiaries [Domain]	MidAmerican Funding, LLC and Subsidiaries [Domain]Additional Paid-in Capital [Member]	MidAmerican Funding, LLC and Subsidiaries [Domain]Retained Earnings [Member]	MidAmerican Funding, LLC and Subsidiaries [Domain]Accumulated Other Comprehensive Income (Loss) [Member]	Sierra Pacific Power Company [Member]	Sierra Pacific Power Company [Member]Common Stock [Member]	Sierra Pacific Power Company [Member]Additional Paid-in Capital [Member]	Sierra Pacific Power Company [Member]Retained Earnings [Member]	Sierra Pacific Power Company [Member]Accumulated Other Comprehensive Income (Loss) [Member]	Nevada Power Company [Member]	Nevada Power Company [Member]Common Stock [Member]	Nevada Power Company [Member]Additional Paid-in Capital [Member]	Nevada Power Company [Member]Retained Earnings [Member]	Nevada Power Company [Member]Accumulated Other Comprehensive Income (Loss) [Member]
Balance (shares) at Dec. 31, 2014		77,000,000																				1,000					1,000
Balance at Dec. 31, 2014	$ 20,573	$ 0	$ 6,423	$ 14,513	$ (494)	$ 131
Balance at Dec. 31, 2014							$ 7,756	$ 2	$ 0	$ 4,479	$ 3,288	$ (13)	$ 4,250	$ 561	$ 3,712	$ (23)	$ 5,073	$ 1,679	$ 3,417	$ (23)	$ 998	$ 0	$ 1,111	$ (111)	$ (2)	$ 2,888	$ 0	$ 2,308	$ 583	$ (3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,388	0	0	2,370	0	18
Net income	2,400
Net income (loss) attributable to parent	2,370						695		0	0	695	0	462		462		458		458		83			83		288			288
Other comprehensive income (loss)	(414)	0	0	0	(414)	0	2		0	0	0	2	(7)			(7)	(7)			(7)
Dividend, noncash, transfer of operations													0				0
Distributions	(21)	0	0	0	0	(21)
Common stock dividends declared							(950)		0	0	(950)	0									(7)			(7)		(13)			(13)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results	67			56		11
Common stock, value, repurchased	(36)	0	(3)	(33)	0	0
Other equity transactions	(22)	$ 0	(17)	0	0	(5)											1		1		2				2
Balance (shares) at Dec. 31, 2015		77,000,000																				1,000					1,000
Balance at Dec. 31, 2015	22,535	$ 0	6,403	16,906	(908)	134
Balance at Dec. 31, 2015							7,503	2	0	4,479	3,033	(11)	4,705	$ 561	4,174	(30)	5,525	1,679	3,876	(30)	1,076	$ 0	1,111	(35)	0	3,163	$ 0	2,308	858	(3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,556	0	0	2,542	0	14
Net income	2,570
Net income (loss) attributable to parent	2,542						763		0	0	763	0	542		542		532		532		84			84		279			279
Other comprehensive income (loss)	(603)	0	0	0	(603)	0	(1)		0	0	0	(1)	3			3	3			3
Stockholders' equity transfer to affiliate																	27			27
Dividend, noncash, transfer of operations													(90)		(117)	(27)	(90)
Distributions	(20)	0	0	0	0	(20)
Common stock dividends declared							$ (875)		0	0	(875)	0									(51)			(51)		(469)			(469)
Other equity transactions	$ (5)	$ 0	(13)	0	0	8											1		1		$ (1)				(1)	$ (1)			(1)
Balance (shares) at Dec. 31, 2016	77,000,000	77,000,000					357,000,000							70,980,203							1,000	1,000				1,000	1,000
Balance at Dec. 31, 2016	$ 24,463	$ 0	6,390	19,448	(1,511)	136
Balance at Dec. 31, 2016	24,327						$ 7,390	2	0	4,479	2,921	(12)	5,160	$ 561	4,599	0	6,086	1,679	4,407	0	$ 1,108	$ 0	1,111	(2)	(1)	$ 2,972	$ 0	2,308	667	(3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,892	0	0	2,870	0	22
Net income	2,910
Net income (loss) attributable to parent	2,870						768		0	0	768	0	605		605		574		574		109			109		255			255
Other comprehensive income (loss)	1,113	0	0	0	1,113	0	(3)		0	0	0	(3)	0				0
Dividend, noncash, transfer of operations													0				0
Distributions	(22)	0	0	0	0	(22)
Common stock dividends declared							$ (600)		0	0	(600)	0									$ (45)			(45)		(548)			(548)
Common stock, value, repurchased	(19)	0	(1)	(18)	0	0
Conversion of Stock, Amount Converted	(100)	0	(6)	(94)	0	0
Other equity transactions	$ (19)	$ 0	(15)	0	0	(4)							1	$ 0	1	0										$ (1)				(1)
Balance (shares) at Dec. 31, 2017	77,000,000	77,000,000					357,000,000							70,980,203							1,000	1,000				1,000	1,000
Balance at Dec. 31, 2017	$ 28,308	$ 0	$ 6,368	$ 22,206	$ (398)	$ 132
Balance at Dec. 31, 2017	$ 28,176						$ 7,555	$ 2	$ 0	$ 4,479	$ 3,089	$ (15)	$ 5,764	$ 561	$ 5,203	$ 0	$ 6,660	$ 1,679	$ 4,981	$ 0	$ 1,172	$ 0	$ 1,111	$ 62	$ (1)	$ 2,678	$ 0	$ 2,308	$ 374	$ (4)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 2,910	$ 2,570	$ 2,400
Net income (loss) attributable to parent	2,870	2,542	2,370
Adjustments to reconcile net income to net cash flows from operating activities:
Other Nonrecurring (Income) Expense	455	62	(8)
Depreciation and amortization	2,646	2,591	2,428
Allowance for equity funds	(76)	(158)	(91)
Equity (income) loss, net of distributions	151	(123)	(115)
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions	260	(67)	(38)
Changes in regulatory assets and liabilities	31	(34)	356
Deferred income taxes and amortization of investment tax credits	19	1,090	1,265
Other, net	(2)	(142)	19
Changes in other operating assets and liabilities, net of effects from acquisitions:
Trade receivables and other assets	(86)	(158)	(9)
Derivative collateral, net	(22)	32	(14)
Pension and other postretirement benefit plans	(91)	(79)	(11)
Accrued property, income and other taxes	(28)	377	877
Accounts payable and other liabilities	50	(28)	(194)
Net cash flows from operating activities	6,066	6,056	6,980
Cash flows from investing activities:
Capital expenditures	(4,571)	(5,090)	(5,875)
Acquisitions, net of cash acquired	(1,113)	(66)	(164)
Increase in restricted cash and investments	(81)	(36)	(28)
Purchases of available-for-sale securities	(190)	(141)	(144)
Proceeds from sales of available-for-sale securities	202	191	142
Equity method investments	(368)	(570)	(202)
Other, net	(12)	(34)	41
Net cash flows from investing activities	(6,133)	(5,746)	(6,230)
Cash flows from financing activities:
Repayments of BHE senior debt and junior subordinated debentures	(2,323)	(2,000)	(850)
Payments for Repurchase of Common Stock	(19)	0	(36)
Proceeds from subsidiary debt	1,763	2,327	2,479
Repayments of subsidiary debt	(1,000)	(1,831)	(1,354)
Net proceeds from (repayments of) short-term debt	2,361	879	(421)
Payment for Debt Extinguishment or Debt Prepayment Cost	(435)	0	0
Other, net	(73)	(65)	(73)
Net cash flows from financing activities	274	(690)	(255)
Effect of exchange rate changes	7	(7)	(4)
Net change in cash and cash equivalents	214	(387)	491
Cash and cash equivalents at beginning of period	721	1,108	617
Cash and cash equivalents at end of period	935	721	1,108
Parent Company [Member]
Cash flows from operating activities:
Net income	2,873	2,545	2,373
Net income (loss) attributable to parent	2,870	2,542	2,370
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	4	4	3
Equity (income) loss, net of distributions	(3,441)	(2,805)	(2,646)
Changes in other operating assets and liabilities, net of effects from acquisitions:
Net cash flows from operating activities	2,450	2,760	2,528
Cash flows from investing activities:
Investments in subsidiaries	1,566	1,080	1,506
Purchases of available-for-sale securities	(71)	(24)	(36)
Proceeds from sales of available-for-sale securities	68	20	47
Repayment of (Issuance of) Notes Receivable with Related Parties, Net	(305)	(307)	19
Other, net	(8)	(5)	(7)
Net cash flows from investing activities	(1,882)	(1,396)	(1,483)
Cash flows from financing activities:
Payments for Repurchase of Common Stock	(19)	0	(36)
Net proceeds from (repayments of) short-term debt	2,498	581	(142)
Payment for Debt Extinguishment or Debt Prepayment Cost	(406)	0	0
Notes payable to affiliate, net	0	69	4
Other, net	(5)	(4)	(1)
Net cash flows from financing activities	(255)	(1,354)	(1,025)
Net change in cash and cash equivalents	313	10	20
Cash and cash equivalents at beginning of period	33	23	3
Cash and cash equivalents at end of period	346	33	23
Repayments of BHE senior debt	1,379	0	0
Repayments of BHE subordinated debt	944	2,000	850
PacifiCorp [Member]
Cash flows from operating activities:
Net income (loss) attributable to parent	768	763	695
Adjustments to reconcile net income to net cash flows from operating activities:
Utilities Operating Expense, Depreciation and Amortization	796	770	757
Allowance for equity funds	(20)	(27)	(33)
Changes in regulatory assets and liabilities	18	122	63
Deferred income taxes and amortization of investment tax credits	70	139	172
Other, net	9	4	6
Changes in other operating assets and liabilities, net of effects from acquisitions:
Trade receivables and other assets	48	(20)	6
Derivative collateral, net	(6)	6	(47)
Increase (Decrease) in Inventories	10	(21)	(7)
Increase (Decrease) in Prepaid Expense	(8)	(5)	(1)
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable	(49)	0	116
Accounts payable and other liabilities	(61)	(163)	7
Net cash flows from operating activities	1,575	1,568	1,734
Cash flows from investing activities:
Capital expenditures	(769)	(903)	(916)
Other, net	40	34	(2)
Net cash flows from investing activities	(729)	(869)	(918)
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	0	0	248
Net proceeds from (repayments of) short-term debt	(190)	250	0
Repayments of long-term debt and capital lease obligations (PacifiCorp)	(58)	(68)	(124)
Common stock dividends	(600)	(875)	(950)
Other, net	(1)	(1)	(1)
Net cash flows from financing activities	(849)	(694)	(827)
Net change in cash and cash equivalents	(3)	5	(11)
Cash and cash equivalents at beginning of period	17	12	23
Cash and cash equivalents at end of period	14	17	12
MidAmerican Energy Company [Member]
Cash flows from operating activities:
Net income (loss) attributable to parent	605	542	462
Adjustments to reconcile net income to net cash flows from operating activities:
Utilities Operating Expense, Depreciation and Amortization	500	479	407
Deferred income taxes and amortization of investment tax credits	332	361	275
Increase (Decrease) in Other Current Assets and Liabilities, Net	1	8	12
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net	37	47	49
Other, net	(59)	(91)	(58)
Changes in other operating assets and liabilities, net of effects from acquisitions:
Increase (Decrease) in Accounts and Other Receivables	58	61	(91)
Derivative collateral, net	2	5	33
Increase (Decrease) in Inventories	19	(27)	(53)
Pension and other postretirement benefit plans	(11)	(6)	(8)
Accrued property, income and other taxes	(41)	107	217
Increase (Decrease) in Accounts Payable	69	39	(76)
Increase (Decrease) in Other Current Assets and Liabilities, Net	1	8	12
Net cash flows from operating activities	1,396	1,403	1,351
Cash flows from investing activities:
Capital expenditures	(1,773)	(1,636)	(1,446)
Purchases of available-for-sale securities	(143)	(138)	(142)
Proceeds from sales of available-for-sale securities	137	158	135
Increase (Decrease) in Restricted Cash and Investments	98	10	0
Other, net	3	11	3
Net cash flows from investing activities	(1,874)	(1,615)	(1,450)
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	990	62	649
Net proceeds from (repayments of) short-term debt	(99)	99	(50)
Repayments of Long-term Debt	(255)	(38)	(426)
Net cash flows from financing activities	636	123	173
Net change in cash and cash equivalents	158	(89)	74
Cash and cash equivalents at beginning of period	14	103	29
Cash and cash equivalents at end of period	172	14	103
MidAmerican Funding, LLC and Subsidiaries [Domain]
Cash flows from operating activities:
Net income (loss) attributable to parent	574	532	458
Adjustments to reconcile net income to net cash flows from operating activities:
Other Nonrecurring (Income) Expense	29	0	0
Utilities Operating Expense, Depreciation and Amortization	500	479	407
Deferred income taxes and amortization of investment tax credits	334	362	276
Increase (Decrease) in Other Current Assets and Liabilities, Net	(1)	8	12
Increase (Decrease) in Other Noncurrent Assets and Liabilities, Net	37	47	49
Other, net	(58)	(92)	(69)
Changes in other operating assets and liabilities, net of effects from acquisitions:
Increase (Decrease) in Accounts and Other Receivables	60	61	(93)
Derivative collateral, net	2	5	33
Increase (Decrease) in Inventories	19	(27)	(53)
Pension and other postretirement benefit plans	(11)	(6)	(8)
Accrued property, income and other taxes	(54)	107	213
Increase (Decrease) in Accounts Payable	69	39	(76)
Increase (Decrease) in Other Current Assets and Liabilities, Net	(1)	8	12
Net cash flows from operating activities	1,380	1,393	1,335
Cash flows from investing activities:
Capital expenditures	(1,773)	(1,636)	(1,446)
Purchases of available-for-sale securities	(143)	(138)	(142)
Proceeds from sales of available-for-sale securities	137	158	135
Proceeds from Sales of Business, Affiliate and Productive Assets	2	2	13
Increase (Decrease) in Restricted Cash and Investments	98	10	0
Other, net	(2)	10	2
Net cash flows from investing activities	(1,877)	(1,614)	(1,438)
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	990	62	649
Net proceeds from (repayments of) short-term debt	(99)	99	(50)
Payment for Debt Extinguishment or Debt Prepayment Cost	(29)	0	0
Repayments of Long-term Debt	(341)	(38)	(426)
Increase (Decrease) in Notes Payable, Related Parties, Current	133	9	3
Other, net	0	1	0
Net cash flows from financing activities	654	133	176
Net change in cash and cash equivalents	157	(88)	73
Cash and cash equivalents at beginning of period	15	103	30
Cash and cash equivalents at end of period	172	15	103
Nevada Power Company [Member]
Cash flows from operating activities:
Net income (loss) attributable to parent	255	279	288
Adjustments to reconcile net income to net cash flows from operating activities:
Other Nonrecurring (Income) Expense	(1)	1	(3)
Utilities Operating Expense, Depreciation and Amortization	308	303	297
Allowance for equity funds	(1)	(2)	(4)
Changes in regulatory assets and liabilities	50	131	4
Deferred Energy Change	(16)	(21)	176
Amortization Income (Expense) of Deferred Energy	16	(107)	36
Deferred income taxes and amortization of investment tax credits	94	78	162
Other, net	(3)	0	13
Changes in other operating assets and liabilities, net of effects from acquisitions:
Trade receivables and other assets	8	26	(40)
Increase (Decrease) in Inventories	6	7	9
Accrued property, income and other taxes	(26)	63	0
Accounts payable and other liabilities	(23)	13	(46)
Net cash flows from operating activities	667	771	892
Cash flows from investing activities:
Capital expenditures	(270)	(335)	(320)
Payments for Previous Acquisition	(77)	0	0
Proceeds from Sale of Other Property, Plant, and Equipment	4	0	9
Other, net	0	0	10
Net cash flows from investing activities	(343)	(335)	(301)
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	91	0	0
Repayments of Long-term Debt	(89)	(224)	(262)
Common stock dividends	(548)	(469)	(13)
Net cash flows from financing activities	(546)	(693)	(275)
Net change in cash and cash equivalents	(222)	(257)	316
Cash and cash equivalents at beginning of period	279	536	220
Cash and cash equivalents at end of period	57	279	536
Sierra Pacific Power Company [Member]
Cash flows from operating activities:
Net income (loss) attributable to parent	109	84	83
Adjustments to reconcile net income to net cash flows from operating activities:
Other Nonrecurring (Income) Expense	0	5	0
Utilities Operating Expense, Depreciation and Amortization	114	118	113
Allowance for equity funds	(4)	1	(2)
Changes in regulatory assets and liabilities	17	(17)	(21)
Deferred Energy Change	(20)	53	81
Amortization Income (Expense) of Deferred Energy	(47)	(54)	17
Deferred income taxes and amortization of investment tax credits	55	49	47
Other, net	(3)	0	(9)
Changes in other operating assets and liabilities, net of effects from acquisitions:
Trade receivables and other assets	4	7	15
Increase (Decrease) in Inventories	(3)	(6)	1
Accrued property, income and other taxes	1	(3)	0
Accounts payable and other liabilities	(41)	6	17
Net cash flows from operating activities	182	243	342
Cash flows from investing activities:
Capital expenditures	(186)	(194)	(252)
Other, net	0	0	2
Net cash flows from investing activities	(186)	(194)	(250)
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	0	1,089	0
Repayments of Long-term Debt	(2)	(1,138)	(1)
Common stock dividends	(45)	(51)	(7)
Net cash flows from financing activities	(47)	(100)	(8)
Net change in cash and cash equivalents	(51)	(51)	84
Cash and cash equivalents at beginning of period	55	106	22
Cash and cash equivalents at end of period	$ 4	$ 55	$ 106

Schedule I Condensed Balance Sh

Schedule I Condensed Balance Sheets (Paranthetical) - $ / shares shares in Millions	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	115	115
Common stock, shares issued	77	77
Common stock, shares outstanding	77	77
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	115	115
Common stock, shares issued	77	77
Common stock, shares outstanding	77	77

Organization and Operations (No

Organization and Operations (Notes)	12 Months Ended
	Dec. 31, 2017
Segment Reporting Information [Line Items]
Organization and Operations	Organization and Operations Berkshire Hathaway Energy Company (" BHE ") is a holding company that owns a highly diversified portfolio of locally managed businesses principally engaged in the energy industry (collectively with its subsidiaries, the "Company") and is a consolidated subsidiary of Berkshire Hathaway Inc. ("Berkshire Hathaway"). The Company's operations are organized as eight business segments: PacifiCorp , MidAmerican Funding, LLC (" MidAmerican Funding ") (which primarily consists of MidAmerican Energy Company (" MidAmerican Energy ")), NV Energy, Inc. (" NV Energy ") (which primarily consists of Nevada Power Company (" Nevada Power ") and Sierra Pacific Power Company (" Sierra Pacific ")), Northern Powergrid Holdings Company (" Northern Powergrid ") (which primarily consists of Northern Powergrid (Northeast) Limited and Northern Powergrid (Yorkshire) plc), BHE Pipeline Group (which consists of Northern Natural Gas Company (" Northern Natural Gas ") and Kern River Gas Transmission Company (" Kern River ")), BHE Transmission (which consists of BHE Canada Holdings Corporation (" AltaLink ") (which primarily consists of AltaLink, L.P. ("ALP")) and BHE U.S. Transmission, LLC ), BHE Renewables and HomeServices of America, Inc. (collectively with its subsidiaries, "HomeServices"). The Company, through these locally managed and operated businesses, owns four utility companies in the United States serving customers in 11 states, two electricity distribution companies in Great Britain, two interstate natural gas pipeline companies in the United States, an electric transmission business in Canada, interests in electric transmission businesses in the United States, a renewable energy business primarily investing in solar, wind, geothermal and hydroelectric projects, the second largest residential real estate brokerage firm in the United States and one of the largest residential real estate brokerage franchise networks in the United States.
PacifiCorp [Member]
Segment Reporting Information [Line Items]
Organization and Operations	Organization and Operations PacifiCorp, which includes PacifiCorp and its subsidiaries, is a United States regulated electric utility company serving retail customers, including residential, commercial, industrial, irrigation and other customers in portions of Utah, Oregon, Wyoming, Washington, Idaho and California. PacifiCorp owns, or has interests in, a number of thermal, hydroelectric, wind-powered and geothermal generating facilities, as well as electric transmission and distribution assets. PacifiCorp also buys and sells electricity on the wholesale market with other utilities, energy marketing companies, financial institutions and other market participants. PacifiCorp is subject to comprehensive state and federal regulation. PacifiCorp's subsidiaries support its electric utility operations by providing coal mining services. PacifiCorp is an indirect subsidiary of Berkshire Hathaway Energy Company ("BHE"), a holding company based in Des Moines, Iowa that owns subsidiaries principally engaged in energy businesses. BHE is a consolidated subsidiary of Berkshire Hathaway Inc. ("Berkshire Hathaway").
MidAmerican Energy Company [Member]
Segment Reporting Information [Line Items]
Organization and Operations	Company Organization MidAmerican Energy Company ("MidAmerican Energy") is a public utility with electric and natural gas operations and is the principal subsidiary of MHC Inc. ("MHC"). MHC is a holding company that conducts no business other than the ownership of its subsidiaries and related corporate services. MHC's nonregulated subsidiaries include Midwest Capital Group, Inc. and MEC Construction Services Co. MHC is the direct wholly owned subsidiary of MidAmerican Funding, LLC, ("MidAmerican Funding"), which is an Iowa limited liability company with Berkshire Hathaway Energy Company ("BHE") as its sole member. BHE is a consolidated subsidiary of Berkshire Hathaway Inc. ("Berkshire Hathaway").
MidAmerican Funding, LLC and Subsidiaries [Domain]
Segment Reporting Information [Line Items]
Organization and Operations	Company Organization MidAmerican Funding, LLC ("MidAmerican Funding") is an Iowa limited liability company with Berkshire Hathaway Energy Company ("BHE") as its sole member. BHE is a consolidated subsidiary of Berkshire Hathaway Inc. ("Berkshire Hathaway"). MidAmerican Funding's direct wholly owned subsidiary is MHC Inc. ("MHC"), which constitutes substantially all of MidAmerican Funding's assets, liabilities and business activities except those related to MidAmerican Funding's long-term debt securities. MHC conducts no business other than the ownership of its subsidiaries and related corporate services. MHC's principal subsidiary is MidAmerican Energy Company ("MidAmerican Energy"), a public utility with electric and natural gas operations. Direct, wholly owned nonregulated subsidiaries of MHC are Midwest Capital Group, Inc. ("Midwest Capital Group") and MEC Construction Services Co.
Nevada Power Company [Member]
Segment Reporting Information [Line Items]
Organization and Operations	Organization and Operations Nevada Power Company , together with its subsidiaries (" Nevada Power "), is a wholly owned subsidiary of NV Energy, Inc. (" NV Energy "), a holding company that also owns Sierra Pacific Power Company (" Sierra Pacific ") and certain other subsidiaries. Nevada Power is a United States regulated electric utility company serving retail customers, including residential, commercial and industrial customers primarily in the Las Vegas, North Las Vegas, Henderson and adjoining areas. NV Energy is an indirect wholly owned subsidiary of Berkshire Hathaway Energy Company (" BHE "). BHE is a holding company based in Des Moines, Iowa that owns subsidiaries principally engaged in energy businesses. BHE is a consolidated subsidiary of Berkshire Hathaway Inc. ("Berkshire Hathaway").
Sierra Pacific Power Company [Member]
Segment Reporting Information [Line Items]
Organization and Operations	Organization and Operations Sierra Pacific Power Company , together with its subsidiaries (" Sierra Pacific "), is a wholly owned subsidiary of NV Energy, Inc. (" NV Energy "), a holding company that also owns Nevada Power Company (" Nevada Power ") and certain other subsidiaries. Sierra Pacific is a United States regulated electric utility company serving retail customers, including residential, commercial and industrial customers and regulated retail natural gas customers primarily in northern Nevada. NV Energy is an indirect wholly owned subsidiary of Berkshire Hathaway Energy Company (" BHE "). BHE is a holding company based in Des Moines, Iowa that owns subsidiaries principally engaged in energy businesses. BHE is a consolidated subsidiary of Berkshire Hathaway Inc. ("Berkshire Hathaway").

Summary of Significant Accounti

Summary of Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2017
Allowance for Doubtful Accounts [Line Items]
Summary of Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of BHE and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. The Consolidated Statements of Operations include the revenue and expenses of any acquired entities from the date of acquisition. Intercompany accounts and transactions have been eliminated. Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; impairment of goodwill; recovery of long-lived assets; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; fair value of assets acquired and liabilities assumed in business combinations; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements. Accounting for the Effects of Certain Types of Regulation PacifiCorp, MidAmerican Energy, Nevada Power, Sierra Pacific, Northern Natural Gas, Kern River and ALP (the "Regulated Businesses") prepare their financial statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, the Regulated Businesses defer the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. The Company continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit the Regulated Businesses' ability to recover their costs. The Company believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at the federal, state and provincial levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be recognized in net income, returned to customers or re-established as accumulated other comprehensive income (loss) ("AOCI"). Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Alternative valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange. Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other current assets and investments and restricted cash and investments on the Consolidated Balance Sheets. Investments The Company's management determines the appropriate classification of investments in debt and equity securities at the acquisition date and reevaluates the classification at each balance sheet date. Investments and restricted cash and investments that management does not intend to use or is restricted from using in current operations are presented as noncurrent on the Consolidated Balance Sheets. Available-for-sale securities are carried at fair value with realized gains and losses, as determined on a specific identification basis, recognized in earnings and unrealized gains and losses recognized in AOCI, net of tax. Realized and unrealized gains and losses on securities in a trust related to the decommissioning of nuclear generation assets are recorded as a net regulatory liability since the Company expects to recover costs for these activities through regulated rates. Trading securities are carried at fair value with realized and unrealized gains and losses recognized in earnings. Held-to-maturity securities are carried at amortized cost, reflecting the ability and intent to hold the securities to maturity. The Company utilizes the equity method of accounting with respect to investments when it possesses the ability to exercise significant influence, but not control, over the operating and financial policies of the investee. The ability to exercise significant influence is presumed when an investor possesses more than 20% of the voting interests of the investee. This presumption may be overcome based on specific facts and circumstances that demonstrate the ability to exercise significant influence is restricted. In applying the equity method, the Company records the investment at cost and subsequently increases or decreases the carrying value of the investment by the Company's share of the net earnings or losses and other comprehensive income (loss) ("OCI") of the investee. The Company records dividends or other equity distributions as reductions in the carrying value of the investment. Certain equity investments are presented on the Consolidated Balance Sheets net of related investment tax credits. Investments gains and losses arise when investments are sold (as determined on a specific identification basis) or are other-than-temporarily impaired. If a decline in value of an investment below cost is deemed other than temporary, the cost of the investment is written down to fair value, with a corresponding charge to earnings. Factors considered in judging whether an impairment is other than temporary include: the financial condition, business prospects and creditworthiness of the issuer; the relative amount of the decline; the Company's ability and intent to hold the investment until the fair value recovers; and the length of time that fair value has been less than cost. Impairment losses on equity securities are charged to earnings. With respect to an investment in a debt security, any resulting impairment loss is recognized in earnings if the Company intends to sell, or expects to be required to sell, the debt security before its amortized cost is recovered. If the Company does not expect to ultimately recover the amortized cost basis even if it does not intend to sell the security, the credit loss component is recognized in earnings and any difference between fair value and the amortized cost basis, net of the credit loss, is reflected in OCI. For regulated investments, any impairment charge is offset by the establishment of a regulatory asset to the extent recovery in regulated rates is probable. Allowance for Doubtful Accounts Trade receivables are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on the Company's assessment of the collectibility of amounts owed to the Company by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. As of December 31, 2017 and 2016 , the allowance for doubtful accounts totaled $40 million and $33 million , respectively, and is included in trade receivables, net on the Consolidated Balance Sheets. Derivatives The Company employs a number of different derivative contracts, which may include forwards, futures, options, swaps and other agreements, to manage its commodity price, interest rate, and foreign currency exchange rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Cash collateral received from or paid to counterparties to secure derivative contract assets or liabilities in excess of amounts offset is included in other current assets on the Consolidated Balance Sheets. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked-to-market and settled amounts are recognized as operating revenue or cost of sales on the Consolidated Statements of Operations. For the Company's derivatives not designated as hedging contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For the Company's derivatives not designated as hedging contracts and for which changes in fair value are not recorded as regulatory assets and liabilities, unrealized gains and losses are recognized on the Consolidated Statements of Operations as operating revenue for sales contracts; cost of sales and operating expense for purchase contracts and electricity, natural gas and fuel swap contracts; and other, net for interest rate swap derivatives. For the Company's derivatives designated as hedging contracts, the Company formally assesses, at inception and thereafter, whether the hedging contract is highly effective in offsetting changes in the hedged item. The Company formally documents hedging activity by transaction type and risk management strategy. Changes in the estimated fair value of a derivative contract designated and qualified as a cash flow hedge, to the extent effective, are included on the Consolidated Statements of Changes in Equity as AOCI, net of tax, until the contract settles and the hedged item is recognized in earnings. The Company discontinues hedge accounting prospectively when it has determined that a derivative contract no longer qualifies as an effective hedge, or when it is no longer probable that the hedged forecasted transaction will occur. When hedge accounting is discontinued because the derivative contract no longer qualifies as an effective hedge, future changes in the estimated fair value of the derivative contract are charged to earnings. Gains and losses related to discontinued hedges that were previously recorded in AOCI will remain in AOCI until the contract settles and the hedged item is recognized in earnings, unless it becomes probable that the hedged forecasted transaction will not occur at which time associated deferred amounts in AOCI are immediately recognized in earnings. Inventories Inventories consist mainly of fuel, which includes coal stocks, stored gas and fuel oil, totaling $352 million and $402 million as of December 31, 2017 and 2016 , respectively, and materials and supplies totaling $536 million and $523 million as of December 31, 2017 and 2016 , respectively. The cost of materials and supplies, coal stocks and fuel oil is determined primarily using the average cost method. The cost of stored gas is determined using either the last-in-first-out ("LIFO") method or the lower of average cost or market. With respect to inventories carried at LIFO cost, the replacement cost would be $22 million and $27 million higher as of December 31, 2017 and 2016 , respectively. Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. The Company capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include capitalized interest, including debt allowance for funds used during construction ("AFUDC"), and equity AFUDC, as applicable to the Regulated Businesses. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. Additionally, MidAmerican Energy has regulatory arrangements in Iowa in which the carrying cost of certain utility plant has been reduced for amounts associated with electric returns on equity exceeding specified thresholds. Depreciation and amortization are generally computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by the Company's various regulatory authorities. Depreciation studies are completed by the Regulated Businesses to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as either a cost of removal regulatory liability or an ARO liability on the Consolidated Balance Sheets, depending on whether the obligation meets the requirements of an ARO. As actual removal costs are incurred, the associated liability is reduced. Generally when the Company retires or sells a component of regulated property, plant and equipment, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of regulated facilities, is capitalized by the Regulated Businesses as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. AFUDC is computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC") and the Alberta Utilities Commission ("AUC"). After construction is completed, the Company is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets. Asset Retirement Obligations The Company recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. The Company's AROs are primarily related to the decommissioning of nuclear generating facilities and obligations associated with its other generating facilities and offshore natural gas pipelines. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. For the Regulated Businesses, the difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability. Impairment The Company evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. The impacts of regulation are considered when evaluating the carrying value of regulated assets. Goodwill Goodwill represents the excess of the purchase price over the fair value of identifiable net assets acquired in business combinations. The Company evaluates goodwill for impairment at least annually and completed its annual review as of October 31. When evaluating goodwill for impairment, the Company estimates the fair value of the reporting unit. If the carrying amount of a reporting unit, including goodwill, exceeds the estimated fair value, then the identifiable assets, including identifiable intangible assets, and liabilities of the reporting unit are estimated at fair value as of the current testing date. The excess of the estimated fair value of the reporting unit over the current estimated fair value of net assets establishes the implied value of goodwill. The excess of the recorded goodwill over the implied goodwill value is charged to earnings as an impairment loss. Significant judgment is required in estimating the fair value of the reporting unit and performing goodwill impairment tests. The Company uses a variety of methods to estimate a reporting unit's fair value, principally discounted projected future net cash flows. Key assumptions used include, but are not limited to, the use of estimated future cash flows; multiples of earnings; and an appropriate discount rate. In estimating future cash flows, the Company incorporates current market information, as well as historical factors. As such, the determination of fair value incorporates significant unobservable inputs. During 2017 , 2016 and 2015 , the Company did not record any material goodwill impairments. The Company records goodwill adjustments for (a) the tax benefit associated with the excess of tax-deductible goodwill over the reported amount of goodwill and (b) changes to the purchase price allocation prior to the end of the measurement period, which is not to exceed one year from the acquisition date. Revenue Recognition Energy Businesses Revenue from energy business customers is recognized as electricity or natural gas is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31, 2017 and 2016 , unbilled revenue was $665 million and $643 million , respectively, and is included in trade receivables, net on the Consolidated Balance Sheets. Rates for energy businesses are established by regulators or contractual arrangements. When preliminary regulated rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. The Company records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations. Real Estate Commission Revenue, Mortgage Revenue and Franchise Royalty Fees Commission revenue from real estate brokerage transactions and related amounts due to agents are recognized when a real estate transaction is closed. Title and escrow closing fee revenue from real estate transactions and related amounts due to the title insurer are recognized at closing. Mortgage fee revenue consists of amounts earned related to application and underwriting fees, and fees on canceled loans. Fees associated with the origination and acquisition of mortgage loans are recognized as earned. Franchise royalty fees are based on a percentage of commissions earned by franchisees on real estate sales and are recognized when the sale closes. Unamortized Debt Premiums, Discounts and Debt Issuance Costs Premiums, discounts and debt issuance costs incurred for the issuance of long-term debt are amortized over the term of the related financing using the effective interest method. Foreign Currency The accounts of foreign-based subsidiaries are measured in most instances using the local currency of the subsidiary as the functional currency. Revenue and expenses of these businesses are translated into United States dollars at the average exchange rate for the period. Assets and liabilities are translated at the exchange rate as of the end of the reporting period. Gains or losses from translating the financial statements of foreign-based operations are included in equity as a component of AOCI. Gains or losses arising from transactions denominated in a currency other than the functional currency of the entity that is party to the transaction are included in earnings. Income Taxes Berkshire Hathaway includes the Company in its consolidated United States federal income tax return. The Company's provision for income taxes has been computed on a stand-alone basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of OCI are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that the Company's regulated businesses deems probable to be passed on to their customers in most state and provincial jurisdictions are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties or as prescribed by various regulatory jurisdictions. The 2017 Tax Reform also creates a one-time repatriation tax on the Company's undistributed foreign corporations' post-1986 accumulated earnings and profits. Therefore, the cumulative undistributed foreign earnings were deemed repatriated to the United States as of December 31, 2017. The Company currently does not believe the deemed repatriation has altered the Company's existing assertion that undistributed earnings will be reinvested indefinitely; however, the Company periodically evaluates its capital requirements and that conclusion could change. As a result of the 2017 Tax Reform, future undistributed earnings are not expected to be subject to tax in the United States. In determining the Company's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by the Company's various regulatory jurisdictions. The Company's income tax returns are subject to continuous examinations by federal, state, local and foreign income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. The Company recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of the Company's federal, state, local and foreign income tax examinations is uncertain, the Company believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on the Company's consolidated financial results. The Company's unrecognized tax benefits are primarily included in accrued property, income and other taxes and other long-term liabilities on the Consolidated Balance Sheets. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations. New Accounting Pronouncements In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2018-02, which amends FASB Accounting Standards Codification ("ASC") Topic 220, "Income Statement - Reporting Comprehensive Income." The amendments in this guidance require a reclassification from accumulated other comprehensive income to retained earnings for the stranded tax effects that were created from the enactment of the 2017 Tax Reform. The reclassification is the difference between the historical income tax rates and the enacted rate for the items previously recorded in accumulated other comprehensive income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted retrospectively to each period(s) in which the effect of the change in the 2017 Tax Reform is recognized. Considering the significant components of the Company's accumulated other comprehensive income relate to (a) unrecognized amounts on retirement benefits of foreign pension plans and (b) unrealized gains on available-for-sale securities, which were reclassified as required by ASU No. 2016-01 that was adopted on January 1, 2018, the adoption of ASU No. 2018-02 will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2017, the FASB issued ASU No. 2017-12, which amends FASB ASC Topic 815, "Derivatives and Hedging." The amendments in this guidance update the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements, expands an entity's ability to hedge non-financial and financial risk components and reduces complexity in fair value hedges of interest rate risk. In addition, it eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in fair value of a hedging instrument to be presented in the same income statement line as the hedged item and also eases certain documentation and assessment requirements. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach by means of a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The Company is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In March 2017, the FASB issued ASU No. 2017-07, which amends FASB ASC Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, “Statement of Cash Flows - Overall.” The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities
PacifiCorp [Member]
Allowance for Doubtful Accounts [Line Items]
Summary of Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of PacifiCorp and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated. Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements. Accounting for the Effects of Certain Types of Regulation PacifiCorp prepares its financial statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, PacifiCorp defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in rates occur. PacifiCorp continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit PacifiCorp's ability to recover its costs. PacifiCorp believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future rates, the related regulatory assets and liabilities will be written off to net income or re-established as accumulated other comprehensive income (loss) ("AOCI"). Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange. Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other current assets and other assets on the Consolidated Balance Sheets. Investments Available-for-sale securities are carried at fair value with realized gains and losses, as determined on a specific identification basis, recognized in earnings and unrealized gains and losses recognized in AOCI, net of tax. As of December 31, 2017 and 2016 , PacifiCorp had no unrealized gains and losses on available-for-sale securities. Trading securities are carried at fair value with realized and unrealized gains and losses recognized in earnings. PacifiCorp utilizes the equity method of accounting with respect to investments when it possesses the ability to exercise significant influence, but not control, over the operating and financial policies of the investee. The ability to exercise significant influence is presumed when an investor possesses more than 20% of the voting interests of the investee. This presumption may be overcome based on specific facts and circumstances that demonstrate the ability to exercise significant influence is restricted. In applying the equity method, PacifiCorp records the investment at cost and subsequently increases or decreases the carrying value of the investment by PacifiCorp's proportionate share of the net earnings or losses and other comprehensive income (loss) ("OCI") of the investee. PacifiCorp records dividends or other equity distributions as reductions in the carrying value of the investment. Allowance for Doubtful Accounts Accounts receivable are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on PacifiCorp's assessment of the collectibility of amounts owed to PacifiCorp by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 7 $ 7 $ 7 Charged to operating costs and expenses, net 15 12 10 Write-offs, net (12 ) (12 ) (10 ) Ending balance $ 10 $ 7 $ 7 Derivatives PacifiCorp employs a number of different derivative contracts, which may include forwards, options, swaps and other agreements, to manage price risk for electricity, natural gas and other commodities and interest rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked-to-market and settled amounts are recognized as operating revenue or energy costs on the Consolidated Statements of Operations. For PacifiCorp's derivative contracts, the settled amount is generally included in rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in rates are recorded as regulatory liabilities or assets. For a derivative contract not probable of inclusion in rates, changes in the fair value are recognized in earnings. Inventories Inventories consist mainly of materials and supplies totaling $235 million and $228 million as of December 31, 2017 , and 2016 , respectively, and fuel stocks, totaling $198 million and $215 million as of December 31, 2017 , and 2016 , respectively. Inventories are stated at the lower of average cost or net realizable value. Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. PacifiCorp capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs, which include debt and equity allowance for funds used during construction ("AFUDC"). The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. Depreciation and amortization are generally computed on the straight-line method based on composite asset class lives prescribed by PacifiCorp's various regulatory authorities or over the assets' estimated useful lives. Depreciation studies are completed periodically to determine the appropriate composite asset class lives, net salvage and depreciation rates. These studies are reviewed and rates are ultimately approved by the various regulatory authorities. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as either a cost of removal regulatory liability or an ARO liability on the Consolidated Balance Sheets, depending on whether the obligation meets the requirements of an ARO. As actual removal costs are incurred, the associated liability is reduced. Generally when PacifiCorp retires or sells a component of regulated property, plant and equipment, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of property, plant and equipment, is capitalized as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. AFUDC is computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC"). After construction is completed, PacifiCorp is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets. Asset Retirement Obligations PacifiCorp recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. PacifiCorp's AROs are primarily associated with its generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability. Impairment The Company evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. The impacts of regulation are considered when evaluating the carrying value of regulated assets. Revenue Recognition Revenue is recognized as electricity is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31, 2017 and 2016 , unbilled revenue was $255 million and $275 million , respectively, and is included in accounts receivable, net on the Consolidated Balance Sheets. Rates charged are established by regulators or contractual arrangements. The determination of sales to individual customers is based on the reading of the customer's meter, which is performed on a systematic basis throughout the month. At the end of each month, energy provided to customers since the date of the last meter reading is estimated, and the corresponding unbilled revenue is recorded. The estimate is reversed in the following month and actual revenue is recorded based on subsequent meter readings. The monthly unbilled revenues of PacifiCorp are determined by the estimation of unbilled energy provided during the period, the assignment of unbilled energy provided to customer classes and the average rate per customer class. Factors that can impact the estimate of unbilled energy include, but are not limited to, seasonal weather patterns, total volumes supplied to the system, line losses, economic impacts and composition of sales among customer classes. PacifiCorp records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations. Income Taxes Berkshire Hathaway includes PacifiCorp in its consolidated United States federal income tax return. Consistent with established regulatory practice, PacifiCorp's provision for income taxes has been computed on a stand-alone basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of OCI are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that PacifiCorp deems probable to be passed on to its customers in most state jurisdictions are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties or as prescribed by various regulatory jurisdictions. Investment tax credits are included in other long-term liabilities on the Consolidated Balance Sheets and were $16 million and $18 million as of December 31, 2017 and 2016 , respectively. In determining PacifiCorp's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by PacifiCorp's various regulatory jurisdictions. PacifiCorp's income tax returns are subject to continuous examinations by federal, state and local income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. PacifiCorp recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of PacifiCorp's federal, state and local income tax examinations is uncertain, PacifiCorp believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on PacifiCorp's consolidated financial results. PacifiCorp's unrecognized tax benefits are primarily included in other long-term liabilities on the Consolidated Balance Sheets. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations. Segment Information PacifiCorp currently has one segment, which includes its regulated electric utility operations. New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. PacifiCorp adopted this guidance January 1, 2018 and the adoption of this guidance will not have a material impact on the Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. PacifiCorp plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. PacifiCorp adopted this guidance on January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when PacifiCorp has the right to invoice as it corresponds directly with the value to the customer of PacifiCorp's performance to date. PacifiCorp plans to quantitatively disaggregate revenue in the required financial statement footnote by customer class.
MidAmerican Energy Company [Member]
Allowance for Doubtful Accounts [Line Items]
Summary of Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Use of Estimates in Preparation of Financial Statements The preparation of the Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Financial Statements. A ccounting for the Effects of Certain Types of Regulation MidAmerican Energy's utility operations are subject to the regulation of the Iowa Utilities Board ("IUB"), the Illinois Commerce Commission ("ICC"), the South Dakota Public Utilities Commission, and the Federal Energy Regulatory Commission ("FERC"). MidAmerican Energy's accounting policies and the accompanying Financial Statements conform to GAAP applicable to rate-regulated enterprises and reflect the effects of the ratemaking process. MidAmerican Energy prepares its financial statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, MidAmerican Energy defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. MidAmerican Energy continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition, that could limit MidAmerican Energy's ability to recover its costs. MidAmerican Energy believes the application of the guidance for regulated operations is appropriate, and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be written off to net income, returned to customers or re-established as accumulated other comprehensive income (loss) ("AOCI"). Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange. Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other current assets and restricted cash and investments on the Balance Sheets. Investments MidAmerican Energy's management determines the appropriate classification of investments in debt and equity securities at the acquisition date and reevaluates the classification at each balance sheet date. Investments that management does not intend to use or is restricted from using in current operations are presented as noncurrent on the Balance Sheets. Available-for-sale securities are carried at fair value with realized gains and losses, as determined on a specific identification basis, recognized in earnings and unrealized gains and losses recognized in AOCI, net of tax. Realized and unrealized gains and losses on securities in a trust related to the decommissioning of the Quad Cities Generating Station Units 1 and 2 ("Quad Cities Station") are recorded as a net regulatory liability because MidAmerican Energy expects to recover costs for these activities through regulated rates. Held-to-maturity securities are carried at amortized cost, reflecting the ability and intent to hold the securities to maturity. Investments gains and losses arise when investments are sold (as determined on a specific identification basis) or are other-than-temporarily impaired. If a decline in value of an investment below cost is deemed other than temporary, the cost of the investment is written down to fair value, with a corresponding charge to earnings. Factors considered in judging whether an impairment is other than temporary include: the financial condition, business prospects and creditworthiness of the issuer; the relative amount of the decline; MidAmerican Energy's ability and intent to hold the investment until the fair value recovers; and the length of time that fair value has been less than cost. Impairment losses on equity securities are charged to earnings. With respect to an investment in a debt security, any resulting impairment loss is recognized in earnings if MidAmerican Energy intends to sell, or expects to be required to sell, the debt security before its amortized cost is recovered. If MidAmerican Energy does not expect to ultimately recover the amortized cost basis even if it does not intend to sell the security, the credit loss component is recognized in earnings and any difference between fair value and the amortized cost basis, net of the credit loss, is reflected in other comprehensive income (loss) ("OCI"). For regulated investments, any impairment charge is offset by the establishment of a regulatory asset to the extent recovery in regulated rates is probable. Allowance for Doubtful Accounts Receivables are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on MidAmerican Energy's assessment of the collectibility of amounts owed to it by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. As of December 31, 2017 and 2016 , the allowance for doubtful accounts totaled $7 million and is included in receivables, net on the Balance Sheets. Derivatives MidAmerican Energy employs a number of different derivative contracts, including forwards, futures, options, swaps and other agreements, to manage price risk for electricity, natural gas and other commodities, and interest rate risk. Derivative contracts are recorded on the Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Cash collateral received from or paid to counterparties to secure derivative contract assets or liabilities in excess of amounts offset is included in other current assets on the Balance Sheets. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked to market, and settled amounts are recognized as operating revenue or cost of sales on the Statements of Operations. For MidAmerican Energy's derivatives not designated as hedging contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For MidAmerican Energy's derivatives designated as hedging contracts, MidAmerican Energy formally assesses, at inception and thereafter, whether the hedging contract is highly effective in offsetting changes in the hedged item. MidAmerican Energy formally documents hedging activity by transaction type and risk management strategy. Changes in the estimated fair value of a derivative contract designated and qualified as a cash flow hedge, to the extent effective, are included on the Statements of Changes in Equity as AOCI, net of tax, until the contract settles and the hedged item is recognized in earnings. All of MidAmerican Energy's derivatives designated as cash flow hedges and the related AOCI were transferred to a subsidiary of BHE on January 1, 2016, as discussed in Note 3 . Inventories Inventories consist mainly of coal stocks, totaling $117 million and $137 million as of December 31, 2017 and 2016 , respectively, materials and supplies, totaling $100 million and $99 million as of December 31, 2017 and 2016 , respectively, and natural gas in storage, totaling $24 million as of December 31, 2017 and 2016 . The cost of materials and supplies, coal stocks and fuel oil is determined using the average cost method. The cost of stored natural gas is determined using the last-in-first-out method. With respect to stored natural gas, the replacement cost would be $22 million and $27 million higher as of December 31, 2017 and 2016 , respectively. Utility Plant, Net General Additions to utility plant are recorded at cost. MidAmerican Energy capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include debt allowance for funds used during construction ("AFUDC") and equity AFUDC. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. Additionally, MidAmerican Energy has regulatory arrangements in Iowa in which the carrying cost of certain utility plant has been reduced for amounts associated with electric returns on equity exceeding specified thresholds and energy benefits associated with certain wind-powered generation. Amounts expensed under this arrangement are included as a component of depreciation and amortization. Depreciation and amortization for MidAmerican Energy's utility operations are computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by its various regulatory authorities. Depreciation studies are completed by MidAmerican Energy to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as either a cost of removal regulatory liability or an ARO liability on the Balance Sheets, depending on whether the obligation meets the requirements of an ARO. As actual removal costs are incurred, the associated liability is reduced. Generally, when MidAmerican Energy retires or sells a component of utility plant, it charges the original cost, net of any proceeds from the disposition to accumulated depreciation. Any gain or loss on disposals of nonregulated assets is recorded through earnings. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of its regulated facilities, is capitalized by MidAmerican Energy as a component of utility plant, with offsetting credits to the Statements of Operations. AFUDC is computed based on guidelines set forth by the FERC. After construction is completed, MidAmerican Energy is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets. Asset Retirement Obligations MidAmerican Energy recognizes AROs when it has a legal obligation to perform decommissioning or removal activities upon retirement of an asset. MidAmerican Energy's AROs are primarily related to decommissioning of the Quad Cities Station and obligations associated with its other generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to utility plant) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in utility plant, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability. Impairment MidAmerican Energy evaluates long-lived assets for impairment, including utility plant, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value. The impacts of regulation are considered when evaluating the carrying value of regulated assets. For all other assets, any resulting impairment loss is reflected on the Statements of Operations. Revenue Recognition Revenue from electric and natural gas customers is recognized as electricity or natural gas is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31, 2017 and 2016 , unbilled revenue was $89 million and $87 million , respectively, and is included in receivables, net on the Balance Sheets. The determination of customer billings is based on a systematic reading of customer meters and applicable rates. At the end of each month, amounts of energy provided to customers since the date of the last meter reading are estimated, and the corresponding unbilled revenue is recorded. Factors that can impact the estimate of unbilled energy include, but are not limited to, seasonal weather patterns, total volumes supplied to the system, line losses, economic impacts and composition of customer classes. Unbilled revenue is reversed in the following month and billed revenue is recorded based on the subsequent meter readings. All of MidAmerican Energy's regulated retail electric and gas sales are subject to energy adjustment clauses. MidAmerican Energy also has costs that are recovered, at least in part, through bill riders, including demand-side management and certain transmission costs. The clauses and riders allow MidAmerican Energy to adjust the amounts charged for electric and gas service as the related costs change. The costs recovered in revenue through use of the adjustment clauses and bill riders are charged to expense in the same year the related revenue is recognized. At any given time, these costs may be over or under collected from customers. The total under collection included in receivables at December 31, 2017 and 2016 , was $72 million and $31 million , respectively. MidAmerican Energy collects from its customers sales and excise taxes assessed by governmental authorities on transactions with customers and later remits the collected taxes to the appropriate authority. If the obligation to pay a particular tax resides with the customer, MidAmerican Energy reports such taxes collected on a net basis and, accordingly, they do not affect the Statement of Operations. Taxes for which the obligation resides with MidAmerican Energy are reported on a gross basis in operating revenue and operating expenses. The amounts reported on a gross basis are not material. Unamortized Debt Premiums, Discounts and Issuance Costs Premiums, discounts and issuance costs incurred for the issuance of long-term debt are amortized over the term of the related financing using the effective interest method. Income Taxes Berkshire Hathaway includes MidAmerican Funding and MidAmerican Energy in its consolidated United States federal income tax return. MidAmerican Funding's and MidAmerican Energy's provisions for income taxes have been computed on a stand-alone basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of OCI are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21%. Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that MidAmerican Energy deems probable to be passed on to its customers in most state jurisdictions are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties or as prescribed by various regulatory jurisdictions. In determining MidAmerican Funding's and MidAmerican Energy's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by MidAmerican Energy's various regulatory jurisdictions. MidAmerican Funding's and MidAmerican Energy's income tax returns are subject to continuous examinations by federal, state and local tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. MidAmerican Funding and MidAmerican Energy recognize the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of their federal, state and local income tax examinations is uncertain, each company believes it has made adequate provisions for its income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on its consolidated financial results. MidAmerican Funding's and MidAmerican Energy's unrecognized tax benefits are primarily included in taxes accrued and other long-term liabilities on their respective Consolidated Balance Sheets. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations. New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, “Statement of Cash Flows - Overall.” The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively, wherein the statement of cash flows of each period presented should be adjusted to reflect the new guidance. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. MidAmerican Energy plans to adopt this guidance effective January 1, 2019, and is currently evaluating the impact on its Financial Statements and disclosures included within Notes to Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No.2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. MidAmerican Energy adopted this guidance effective January 1, 2018, under the modified retrospective method and the adoption will not have an impact on its Financial Statements but will increase the disclosures included within Notes to Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized equal to what MidAmerican Energy has the right to invoice as it corresponds directly with the value to the customer of MidAmerican Energy's performance to date. MidAmerican Energy's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by customer class for each segment.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Allowance for Doubtful Accounts [Line Items]
Summary of Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies In addition to the following significant accounting policies, refer to Note 2 of MidAmerican Energy's Notes to Financial Statements for significant accounting policies of MidAmerican Funding. Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of MidAmerican Funding and its subsidiaries in which it held a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated, other than those between rate-regulated operations. Goodwill Goodwill represents the excess of the purchase price over the fair value of identifiable net assets acquired when MidAmerican Funding purchased MHC. MidAmerican Funding evaluates goodwill for impairment at least annually and completed its annual review as of October 31. When evaluating goodwill for impairment, MidAmerican Funding estimates the fair value of the reporting unit. If the carrying amount of a reporting unit, including goodwill, exceeds the estimated fair value, then the identifiable assets, including identifiable intangible assets, and liabilities of the reporting unit are estimated at fair value as of the current testing date. The excess of the estimated fair value of the reporting unit over the current estimated fair value of net assets establishes the implied value of goodwill. The excess of the recorded goodwill over the implied goodwill value is charged to earnings as an impairment loss. Significant judgment is required in estimating the fair value of the reporting unit and performing goodwill impairment tests. MidAmerican Funding uses a variety of methods to estimate a reporting unit's fair value, principally discounted projected future net cash flows. Key assumptions used include, but are not limited to, the use of estimated future cash flows; multiples of earnings; and an appropriate discount rate. In estimating future cash flows, MidAmerican Funding incorporates current market information, as well as historical factors. As such, the determination of fair value incorporates significant unobservable inputs. During 2017 , 2016 and 2015 , MidAmerican Funding did not record any goodwill impairments.
Nevada Power Company [Member]
Allowance for Doubtful Accounts [Line Items]
Summary of Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of Nevada Power and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated. The Consolidated Statements of Comprehensive Income have been omitted as net income equals comprehensive income for the years ended December 31, 2017 , 2016 and 2015 . Certain amounts in the prior period Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported operating income, net income or retained earnings. Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; recovery of long-lived assets; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements. Accounting for the Effects of Certain Types of Regulation Nevada Power prepares its Consolidated Financial Statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, Nevada Power defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. Nevada Power continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit Nevada Power 's ability to recover its costs. Nevada Power believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be written off to net income, returned to customers or re-established as accumulated other comprehensive income (loss). Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange. Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other assets and other current assets on the Consolidated Balance Sheets. Allowance for Doubtful Accounts Accounts receivable are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on Nevada Power 's assessment of the collectibility of amounts owed to Nevada Power by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. Nevada Power also has the ability to assess deposits on customers who have delayed payments or who are deemed to be a credit risk. The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 12 $ 13 $ 14 Charged to operating costs and expenses, net 15 16 16 Write-offs, net (11 ) (17 ) (17 ) Ending balance $ 16 $ 12 $ 13 Derivatives Nevada Power employs a number of different derivative contracts, which may include forwards, futures, options, swaps and other agreements, to manage its commodity price and interest rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked‑to‑market and settled amounts are recognized as cost of fuel, energy and capacity on the Consolidated Statements of Operations. For Nevada Power 's derivative contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For a derivative contract not probable of inclusion in rates, changes in the fair value are recognized in earnings. Inventories Inventories consist mainly of materials and supplies totaling $56 million and $60 million as of December 31 , 2017 and 2016 , respectively, and fuel, which includes coal stock, stored natural gas and fuel oil, totaling $3 million and $13 million as of December 31 , 2017 and 2016 , respectively. The cost is determined using the average cost method. Materials are charged to inventory when purchased and are expensed or capitalized to construction work in process, as appropriate, when used. Fuel costs are recovered from retail customers through the base tariff energy rates and deferred energy accounting adjustment charges approved by the Public Utilities Commission of Nevada ("PUCN"). Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. Nevada Power capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include debt allowance for funds used during construction ("AFUDC"), and equity AFUDC, as applicable. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. The cost of repairs and minor replacements are charged to expense when incurred with the exception of costs for generation plant maintenance under certain long-term service agreements. Costs under these agreements are expensed straight-line over the term of the agreements as approved by the PUCN. Depreciation and amortization are generally computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by Nevada Power 's various regulatory authorities. Depreciation studies are completed by Nevada Power to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as a non-current regulatory liability on the Consolidated Balance Sheets. As actual removal costs are incurred, the associated liability is reduced. Generally when Nevada Power retires or sells a component of regulated property, plant and equipment depreciated using the composite method, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings with the exception of material gains or losses on regulated property, plant and equipment depreciated on a straight-line basis, which is then recorded to a regulatory asset or liability. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of regulated facilities, are capitalized as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. The rate applied to construction costs is the lower of the PUCN allowed rate of return and rates computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC"). After construction is completed, Nevada Power is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets. Nevada Power 's AFUDC rate used during 2017 and 2016 was 8.09% . Asset Retirement Obligations Nevada Power recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. Nevada Power 's AROs are primarily associated with its generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability on the Consolidated Balance Sheets. The costs are not recovered in rates until the work has been completed. Impairment of Long-Lived Assets Nevada Power evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. As substantially all property, plant and equipment was used in regulated businesses as of December 31 , 2017 , the impacts of regulation are considered when evaluating the carrying value of regulated assets. Income Taxes Berkshire Hathaway includes Nevada Power in its consolidated United States federal income tax return. Consistent with established regulatory practice, Nevada Power 's provision for income taxes has been computed on a separate return basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of other comprehensive income ("OCI") are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property‑related basis differences and other various differences that Nevada Power deems probable to be passed on to its customers are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties. In determining Nevada Power 's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by Nevada Power 's various regulatory jurisdictions. Nevada Power 's income tax returns are subject to continuous examinations by federal, state and local income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. Nevada Power recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of Nevada Power 's federal, state and local income tax examinations is uncertain, Nevada Power believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on Nevada Power 's consolidated financial results. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations. Revenue Recognition Revenue is recognized as electricity is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31 , 2017 and 2016 , unbilled revenue was $111 million and $91 million , respectively, and is included in accounts receivable, net on the Consolidated Balance Sheets. Rates are established by regulators or contractual arrangements. When preliminary rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. Nevada Power records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations. Nevada Power primarily buys energy and natural gas to satisfy its customer load requirements. Due to changes in retail customer load requirements, Nevada Power may not take physical delivery of the energy or natural gas. Nevada Power may sell the excess energy or natural gas to the wholesale market. In such instances, it is Nevada Power 's policy to record such sales net in cost of fuel, energy and capacity. Unamortized Debt Premiums, Discounts and Issuance Costs Premiums, discounts and financing costs incurred for the issuance of long-term debt are amortized over the term of the related financing on a straight-line basis. Segment Information Nevada Power currently has one segment, which includes its regulated electric utility operations. New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. Nevada Power plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Nevada Power adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when Nevada Power has the right to invoice as it corresponds directly with the value to the customer of Nevada Power's performance to date. Nevada Power's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by customer class.
Sierra Pacific Power Company [Member]
Allowance for Doubtful Accounts [Line Items]
Summary of Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of Sierra Pacific and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated. The Consolidated Statements of Comprehensive Income have been omitted as net income equals comprehensive income for the years ended December 31, 2017 , 2016 and 2015 . Certain amounts in the prior period Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported operating income, net income or retained earnings. Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; recovery of long-lived assets; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements. Accounting for the Effects of Certain Types of Regulation Sierra Pacific prepares its Consolidated Financial Statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, Sierra Pacific defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. Sierra Pacific continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit Sierra Pacific 's ability to recover its costs. Sierra Pacific believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be written off to net income, returned to customers or re-established as accumulated other comprehensive income (loss). Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange. Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other assets and other current assets on the Consolidated Balance Sheets. Allowance for Doubtful Accounts Accounts receivable are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on Sierra Pacific 's assessment of the collectibility of amounts owed to Sierra Pacific by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. Sierra Pacific also has the ability to assess deposits on customers who have delayed payments or who are deemed to be a credit risk. The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 2 $ 1 $ 2 Charged to operating costs and expenses, net 2 2 1 Write-offs, net (2 ) (1 ) (2 ) Ending balance $ 2 $ 2 $ 1 Derivatives Sierra Pacific employs a number of different derivative contracts, which may include forwards, futures, options, swaps and other agreements, to manage its commodity price and interest rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked‑to‑market and settled amounts are recognized as cost of fuel, energy and capacity or natural gas purchased for resale on the Consolidated Statements of Operations. For Sierra Pacific 's derivative contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For a derivative contract not probable of inclusion in rates, changes in the fair value are recognized in earnings. Inventories Inventories consist mainly of materials and supplies totaling $42 million and $36 million as of December 31 , 2017 and 2016 , respectively, and fuel, which includes coal stock, stored natural gas and fuel oil, totaling $7 million and $9 million as of December 31 , 2017 and 2016 , respectively. The cost is determined using the average cost method. Materials are charged to inventory when purchased and are expensed or capitalized to construction work in process, as appropriate, when used. Fuel costs are recovered from retail customers through the base tariff energy rates and deferred energy accounting adjustment charges approved by the Public Utilities Commission of Nevada ("PUCN"). Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. Sierra Pacific capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include debt allowance for funds used during construction ("AFUDC"), and equity AFUDC, as applicable. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. The cost of repairs and minor replacements are charged to expense when incurred with the exception of costs for generation plant maintenance under certain long-term service agreements. Costs under these agreements are expensed straight-line over the term of the agreements as approved by the PUCN. Depreciation and amortization are generally computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by Sierra Pacific 's various regulatory authorities. Depreciation studies are completed by Sierra Pacific to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as a non-current regulatory liability on the Consolidated Balance Sheets. As actual removal costs are incurred, the associated liability is reduced. Generally when Sierra Pacific retires or sells a component of regulated property, plant and equipment depreciated using the composite method, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings with the exception of material gains or losses on regulated property, plant and equipment depreciated on a straight-line basis, which is then recorded to a regulatory asset or liability. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of regulated facilities, are capitalized as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. The rate applied to construction costs is the lower of the PUCN allowed rate of return and rates computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC"). After construction is completed, Sierra Pacific is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets. Sierra Pacific 's AFUDC rate used during 2017 and 2016 was 6.65% and 7.62% for electric, 5.63% and 6.02% for natural gas, and 6.55% and 7.44% for common facilities, respectively. Asset Retirement Obligations Sierra Pacific recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. Sierra Pacific 's AROs are primarily associated with its generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability on the Consolidated Balance Sheets. The costs are not recovered in rates until the work has been completed. Impairment of Long-Lived Assets Sierra Pacific evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. As substantially all property, plant and equipment was used in regulated businesses as of December 31 , 2017 , the impacts of regulation are considered when evaluating the carrying value of regulated assets. Income Taxes Berkshire Hathaway includes Sierra Pacific in its consolidated United States federal income tax return. Consistent with established regulatory practice, Sierra Pacific 's provision for income taxes has been computed on a separate return basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of other comprehensive income ("OCI") are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that Sierra Pacific deems probable to be passed on to its customers are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties. In determining Sierra Pacific 's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by Sierra Pacific 's various regulatory jurisdictions. Sierra Pacific 's income tax returns are subject to continuous examinations by federal, state and local income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. Sierra Pacific recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of Sierra Pacific 's federal, state and local income tax examinations is uncertain, Sierra Pacific believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on Sierra Pacific 's consolidated financial results. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations. Revenue Recognition Revenue is recognized as electricity or natural gas is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31 , 2017 and 2016 , unbilled revenue was $62 million and $52 million , respectively, and is included in accounts receivable, net on the Consolidated Balance Sheets. Rates are established by regulators or contractual arrangements. When preliminary rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. Sierra Pacific records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations. Sierra Pacific primarily buys energy and natural gas to satisfy its customer load requirements. Due to changes in retail customer load requirements, Sierra Pacific may not take physical delivery of the energy or natural gas. Sierra Pacific may sell the excess energy or natural gas to the wholesale market. In such instances, it is Sierra Pacific 's policy to allocate the natural gas sales between generation and natural gas retail based on usage. The energy sales and natural gas sales allocated to generation are recorded net in cost of fuel, energy and capacity. The natural gas sales allocated to natural gas retail is recorded as wholesale revenue. Unamortized Debt Premiums, Discounts and Issuance Costs Premiums, discounts and financing costs incurred for the issuance of long-term debt are amortized over the term of the related financing on a straight-line basis. New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. Sierra Pacific plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Sierra Pacific adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when Sierra Pacific has the right to invoice as it corresponds directly with the value to the customer of Sierra Pacific's performance to date. Sierra Pacific's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by segment and customer class.

Business Acquisitions (Notes)

Business Acquisitions (Notes)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Acquisitions [Text Block]	Business Acquisitions In 2017, the Company completed various acquisitions totaling $ 1.1 billion , net of cash acquired. The purchase price for each acquisition was allocated to the assets acquired and liabilities assumed, which primarily related to residential real estate brokerage businesses, development and construction costs for the 110-megawatt Alamo 6 and the 50-megawatt Pearl solar projects, and the remaining 25% interest in the Silverhawk natural gas-fueled generation facility at Nevada Power. As a result of the various acquisitions, the Company acquired assets of $1.1 billion , assumed liabilities of $487 million and recognized goodwill of $508 million . In 2016 and 2015, the Company completed various acquisitions totaling $66 million and $164 million , net of cash acquired, respectively. The purchase price for each acquisition was allocated to the assets acquired and liabilities assumed. The assets acquired consisted of property, plant and equipment, development and construction costs for renewable projects, other working capital items, goodwill of $50 million and $33 million , respectively, and other identifiable intangible assets. The liabilities assumed totaled $54 million and $84 million , respectively.

Property, Plant and Equipment,

Property, Plant and Equipment, Net (Notes)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net [Text Block]	Property, Plant and Equipment, Net Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Regulated assets: Utility generation, transmission and distribution systems 5-80 years $ 74,660 $ 71,536 Interstate natural gas pipeline assets 3-80 years 7,176 6,942 81,836 78,478 Accumulated depreciation and amortization (24,478 ) (23,603 ) Regulated assets, net 57,358 54,875 Nonregulated assets: Independent power plants 5-30 years 6,010 5,594 Other assets 3-30 years 1,489 1,002 7,499 6,596 Accumulated depreciation and amortization (1,542 ) (1,060 ) Nonregulated assets, net 5,957 5,536 Net operating assets 63,315 60,411 Construction work-in-progress 2,556 2,098 Property, plant and equipment, net $ 65,871 $ 62,509 Construction work-in-progress includes $2.2 billion and $1.8 billion as of December 31, 2017 and 2016 , respectively, related to the construction of regulated assets. During the fourth quarter of 2016, MidAmerican Energy revised its electric and gas depreciation rates based on the results of a new depreciation study, the most significant impact of which was longer estimated useful lives for certain wind-powered generating facilities. The effect of this change was to reduce depreciation and amortization expense by $3 million in 2016 and $34 million annually based on depreciable plant balances at the time of the change.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net [Text Block]	Property, Plant and Equipment, Net Refer to Note 4 of MidAmerican Energy's Notes to Financial Statements. In addition to MidAmerican Energy's property, plant and equipment, net, MidAmerican Funding had nonregulated property gross of $24 million and $22 million as of December 31, 2017 and 2016 , respectively, related accumulated depreciation and amortization of $10 million and $9 million as of December 31, 2017 and 2016 , respectively, and construction work-in-progress of $1 million as of December 31, 2016, which consisted primarily of a corporate aircraft owned by MHC.
MidAmerican Energy Company [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net [Text Block]	Property, Plant and Equipment, Net Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant in service: Generation 20-70 years $ 12,107 $ 11,282 Transmission 52-75 years 1,838 1,726 Electric distribution 20-75 years 3,380 3,197 Gas distribution 29-75 years 1,640 1,565 Utility plant in service 18,965 17,770 Accumulated depreciation and amortization (5,561 ) (5,448 ) Utility plant in service, net 13,404 12,322 Nonregulated property, net: Nonregulated property gross 20-50 years 7 7 Accumulated depreciation and amortization (1 ) (1 ) Nonregulated property, net 6 6 13,410 12,328 Construction work-in-progress 797 493 Property, plant and equipment, net $ 14,207 $ 12,821 Nonregulated property includes land, computer software and other assets not recoverable for regulated utility purposes. The average depreciation and amortization rates applied to depreciable utility plant for the years ended December 31 were as follows: 2017 2016 2015 Electric 2.6 % 2.8 % 3.0 % Gas 2.7 % 2.9 % 2.9 % During the fourth quarter of 2016, MidAmerican Energy revised its electric and gas depreciation rates based on the results of a new depreciation study, the most significant impact of which was longer estimated useful lives for certain wind-powered generating facilities. The effect of this change was to reduce depreciation and amortization expense by $3 million in 2016 and $34 million annually based on depreciable plant balances at the time of the change.
PacifiCorp [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net [Text Block]	Property, Plant and Equipment, Net Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility Plant: Generation 14 - 67 years $ 12,490 $ 12,371 Transmission 58 - 75 years 6,226 6,055 Distribution 20 - 70 years 6,792 6,590 Intangible plant (1) 5 - 62 years 937 884 Other 5 - 60 years 1,435 1,384 Utility plant in service 27,880 27,284 Accumulated depreciation and amortization (9,366 ) (8,790 ) Utility plant in service, net 18,514 18,494 Other non-regulated, net of accumulated depreciation and amortization 45 years 11 11 Plant, net 18,525 18,505 Construction work-in-progress 678 657 Property, plant and equipment, net $ 19,203 $ 19,162 (1) Computer software costs included in intangible plant are initially assigned a depreciable life of 5 to 10 years. The average depreciation and amortization rate applied to depreciable property, plant and equipment was 2.9% for the years ended December 31, 2017 , 2016 and 2015 , respectively. Unallocated Acquisition Adjustments PacifiCorp has unallocated acquisition adjustments that represent the excess of costs of the acquired interests in property, plant and equipment purchased from the entity that first devoted the assets to utility service over their net book value in those assets. These unallocated acquisition adjustments included in other property, plant and equipment had an original cost of $156 million as of December 31, 2017 and 2016 , respectively, and accumulated depreciation of $122 million and $117 million as of December 31, 2017 and 2016 , respectively.
Nevada Power Company [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net [Text Block]	Property, Plant and Equipment, Net Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant: Generation 30 - 55 years $ 3,707 $ 4,271 Distribution 20 - 65 years 3,314 3,231 Transmission 45 - 65 years 1,860 1,846 General and intangible plant 5 - 65 years 793 738 Utility plant 9,674 10,086 Accumulated depreciation and amortization (2,871 ) (3,205 ) Utility plant, net 6,803 6,881 Other non-regulated, net of accumulated depreciation and amortization 45 years 1 2 Plant, net 6,804 6,883 Construction work-in-progress 73 114 Property, plant and equipment, net $ 6,877 $ 6,997 Almost all of Nevada Power 's plant is subject to the ratemaking jurisdiction of the PUCN and the FERC. Nevada Power 's depreciation and amortization expense, as authorized by the PUCN, stated as a percentage of the depreciable property balances as of December 31 , 2017 , 2016 and 2015 was 3.2% , 3.2% and 3.0% , respectively. Nevada Power is required to file a utility plant depreciation study every six years as a companion filing with the triennial general rate case filings. Construction work-in-progress is related to the construction of regulated assets. During 2017, Nevada Power performed a depreciation study, in which the depreciation rates will be implemented in January 2018. The study results in shorter estimated useful lives at the Navajo Generating Station and longer average service lives for various other utility plant groups. The net effect of these changes, based on the study, will increase depreciation and amortization expense by $7 million annually based on depreciable plant balances at the time of the change. Acquisitions In April 2017, Nevada Power purchased the remaining 25% interest in the Silverhawk natural gas-fueled generating facility for $77 million . The Public Utilities Commission of Nevada ("PUCN") approved the purchase of the facility in Nevada Power's triennial Integrated Resource Plan filing in December 2015. The purchase price was allocated to the assets acquired, consisting primarily of generation utility plant, and no significant liabilities were assumed.
Sierra Pacific Power Company [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Net [Text Block]	Property, Plant and Equipment, Net Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant: Electric generation 25 - 60 years $ 1,144 $ 1,137 Electric distribution 20 - 100 years 1,459 1,417 Electric transmission 50 - 100 years 786 771 Electric general and intangible plant 5 - 70 years 181 164 Natural gas distribution 35 - 70 years 390 381 Natural gas general and intangible plant 5 - 70 years 14 15 Common general 5 - 70 years 294 267 Utility plant 4,268 4,152 Accumulated depreciation and amortization (1,513 ) (1,442 ) Utility plant, net 2,755 2,710 Other non-regulated, net of accumulated depreciation and amortization 70 years 5 5 Plant, net 2,760 2,715 Construction work-in-progress 132 107 Property, plant and equipment, net $ 2,892 $ 2,822 All of Sierra Pacific 's plant is subject to the ratemaking jurisdiction of the PUCN and the FERC. Sierra Pacific 's depreciation and amortization expense, as authorized by the PUCN, stated as a percentage of the depreciable property balances as of December 31 , 2017 , 2016 and 2015 was 3.0% , 3.0% and 2.9% , respectively. Sierra Pacific is required to file a utility plant depreciation study every six years as a companion filing with the triennial general rate case filings. Construction work-in-progress is related to the construction of regulated assets. In January 2017, Sierra Pacific revised its electric and gas depreciation rates based on the results of a new depreciation study performed in 2016, the most significant impact of which was shorter estimated useful lives at the Valmy Generating Station. The effect of this change increased depreciation and amortization expense by $9 million annually based on depreciable plant balances at the time of the study. However, the PUCN ordered the change relating to the Valmy Generating Station of $7 million annually be deferred for future recovery through a regulatory asset.

Jointly Owned Utility Facilitie

Jointly Owned Utility Facilities (Notes)	12 Months Ended
	Dec. 31, 2017
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Text Block]	Jointly Owned Utility Facilities Under joint facility ownership agreements, the Domestic Regulated Businesses, as tenants in common, have undivided interests in jointly owned generation, transmission, distribution and pipeline common facilities. The Company accounts for its proportionate share of each facility and each joint owner has provided financing for its share of each facility. Operating costs of each facility are assigned to joint owners based on their percentage of ownership or energy production, depending on the nature of the cost. Operating costs and expenses on the Consolidated Statements of Operations include the Company's share of the expenses of these facilities. The amounts shown in the table below represent the Company's share in each jointly owned facility included in property, plant and equipment, net as of December 31, 2017 (dollars in millions): Accumulated Construction Company Facility In Depreciation and Work-in- Share Service Amortization Progress PacifiCorp: Jim Bridger Nos. 1-4 67 % $ 1,442 $ 616 $ 12 Hunter No. 1 94 474 172 7 Hunter No. 2 60 297 106 1 Wyodak 80 469 216 1 Colstrip Nos. 3 and 4 10 247 131 4 Hermiston 50 180 81 1 Craig Nos. 1 and 2 19 365 231 3 Hayden No. 1 25 74 34 — Hayden No. 2 13 43 21 — Foote Creek 79 40 26 — Transmission and distribution facilities Various 794 238 67 Total PacifiCorp 4,425 1,872 96 MidAmerican Energy: Louisa No. 1 88 % 807 432 8 Quad Cities Nos. 1 and 2 (1) 25 698 387 20 Walter Scott, Jr. No. 3 79 617 316 8 Walter Scott, Jr. No. 4 (2) 60 456 112 1 George Neal No. 4 41 307 159 1 Ottumwa No. 1 52 567 206 40 George Neal No. 3 72 425 183 7 Transmission facilities Various 249 87 1 Total MidAmerican Energy 4,126 1,882 86 NV Energy: Navajo 11 % 220 152 — Valmy 50 388 233 1 Transmission facilities Various 206 45 — Total NV Energy 814 430 1 BHE Pipeline Group - common facilities Various 286 169 — Total $ 9,651 $ 4,353 $ 183 (1) Includes amounts related to nuclear fuel. (2) Facility in-service and accumulated depreciation and amortization amounts are net of credits applied under Iowa revenue sharing arrangements totaling $319 million and $81 million , respectively.
PacifiCorp [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Text Block]	Jointly Owned Utility Facilities Under joint facility ownership agreements with other utilities, PacifiCorp, as a tenant in common, has undivided interests in jointly owned generation, transmission and distribution facilities. PacifiCorp accounts for its proportionate share of each facility, and each joint owner has provided financing for its share of each facility. Operating costs of each facility are assigned to joint owners based on their percentage of ownership or energy production, depending on the nature of the cost. Operating costs and expenses on the Consolidated Statements of Operations include PacifiCorp's share of the expenses of these facilities. The amounts shown in the table below represent PacifiCorp's share in each jointly owned facility included in property, plant and equipment, net as of December 31, 2017 (dollars in millions): Facility Accumulated Construction PacifiCorp in Depreciation and Work-in- Share Service Amortization Progress Jim Bridger Nos. 1 - 4 67 % $ 1,442 $ 616 $ 12 Hunter No. 1 94 474 172 7 Hunter No. 2 60 297 106 1 Wyodak 80 469 216 1 Colstrip Nos. 3 and 4 10 247 131 4 Hermiston 50 180 81 1 Craig Nos. 1 and 2 19 365 231 3 Hayden No. 1 25 74 34 — Hayden No. 2 13 43 21 — Foote Creek 79 40 26 — Transmission and distribution facilities Various 794 238 67 Total $ 4,425 $ 1,872 $ 96
MidAmerican Energy Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Text Block]	Jointly Owned Utility Facilities Under joint facility ownership agreements with other utilities, MidAmerican Energy, as a tenant in common, has undivided interests in jointly owned generation and transmission facilities. MidAmerican Energy accounts for its proportionate share of each facility, and each joint owner has provided financing for its share of each facility. Operating costs of each facility are assigned to joint owners based on their percentage of ownership or energy production, depending on the nature of the cost. Operating costs and expenses on the Statements of Operations include MidAmerican Energy's share of the expenses of these facilities. The amounts shown in the table below represent MidAmerican Energy's share in each jointly owned facility included in property, plant and equipment, net as of December 31, 2017 (dollars in millions): Accumulated Construction Company Plant in Depreciation and Work-in- Share Service Amortization Progress Louisa Unit No. 1 88 % $ 807 $ 432 $ 8 Quad Cities Unit Nos. 1 & 2 (1) 25 698 387 20 Walter Scott, Jr. Unit No. 3 79 617 316 8 Walter Scott, Jr. Unit No. 4 (2) 60 456 112 1 George Neal Unit No. 4 41 307 159 1 Ottumwa Unit No. 1 52 567 206 40 George Neal Unit No. 3 72 425 183 7 Transmission facilities Various 249 87 1 Total $ 4,126 $ 1,882 $ 86 (1) Includes amounts related to nuclear fuel. (2) Plant in service and accumulated depreciation and amortization amounts are net of credits applied under Iowa revenue sharing arrangements totaling $319 million and $81 million , respectively.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Text Block]	Jointly Owned Utility Facilities Refer to Note 5 of MidAmerican Energy's Notes to Financial Statements.
Nevada Power Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Text Block]	Jointly Owned Utility Facilities Under joint facility ownership agreements, Nevada Power , as tenants in common, has undivided interests in jointly owned generation and transmission facilities. Nevada Power accounts for its proportionate share of each facility and each joint owner has provided financing for its share of each facility. Operating costs of each facility are assigned to joint owners based on their percentage of ownership or energy production, depending on the nature of the cost. Operating costs and expenses on the Consolidated Statements of Operations include Nevada Power 's share of the expenses of these facilities. The amounts shown in the table below represent Nevada Power 's share in each jointly owned facility included in property, plant and equipment, net as of December 31 , 2017 (dollars in millions): Nevada Construction Power's Utility Accumulated Work-in- Share Plant Depreciation Progress Navajo Generating Station 11 % $ 220 $ 152 $ — ON Line Transmission Line 24 146 16 — Other transmission facilities Various 48 26 — Total $ 414 $ 194 $ —
Sierra Pacific Power Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Text Block]	Jointly Owned Utility Facilities Under joint facility ownership agreements, Sierra Pacific , as tenants in common, has undivided interests in jointly owned generation and transmission facilities. Sierra Pacific accounts for its proportionate share of each facility and each joint owner has provided financing for its share of each facility. Operating costs of each facility are assigned to joint owners based on their percentage of ownership or energy production, depending on the nature of the cost. Operating costs and expenses on the Consolidated Statements of Operations include Sierra Pacific 's share of the expenses of these facilities. The amounts shown in the table below represent Sierra Pacific 's share in each jointly owned facility included in property, plant and equipment, net as of December 31 , 2017 (dollars in millions): Sierra Construction Pacific's Utility Accumulated Work-in- Share Plant Depreciation Progress Valmy Generating Station 50 % $ 388 $ 233 $ 1 ON Line Transmission Line 1 8 1 — Valmy Transmission 50 4 2 — Total $ 400 $ 236 $ 1

Regulatory Matters (Notes)

Regulatory Matters (Notes)	12 Months Ended
	Dec. 31, 2017
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Matters [Text Block]	Regulatory Matters Regulatory Assets Regulatory assets represent costs that are expected to be recovered in future regulated rates. The Company's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Employee benefit plans (1) 16 years $ 675 $ 816 Asset disposition costs Various 387 281 Asset retirement obligations 13 years 334 301 Abandoned projects 3 years 156 159 Deferred operating costs 13 years 147 97 Deferred income taxes (2) Various 143 1,754 Unrealized loss on regulated derivative contracts 4 years 122 154 Unamortized contract values 6 years 89 98 Deferred net power costs 2 years 58 38 Other Various 839 759 Total regulatory assets $ 2,950 $ 4,457 Reflected as: Current assets $ 189 $ 150 Noncurrent assets 2,761 4,307 Total regulatory assets $ 2,950 $ 4,457 (1) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized. (2) Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. The Company had regulatory assets not earning a return on investment of $1.1 billion and $2.8 billion as of December 31, 2017 and 2016 , respectively. Regulatory Liabilities Regulatory liabilities represent income to be recognized or amounts to be returned to customers in future periods. The Company's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) Various $ 4,143 $ 25 Cost of removal (2) 27 years 2,349 2,242 Levelized depreciation 22 years 332 244 Asset retirement obligations 35 years 177 122 Impact fees 6 years 89 90 Employee benefit plans (3) 11 years 69 25 Deferred net power costs 2 years 8 64 Unrealized gain on regulated derivative contracts 1 year 3 6 Other Various 341 302 Total regulatory liabilities $ 7,511 $ 3,120 Reflected as: Current liabilities $ 202 $ 187 Noncurrent liabilities 7,309 2,933 Total regulatory liabilities $ 7,511 $ 3,120 (1) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts. (2) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost. (3) Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized. ALP General Tariff Application ("GTA") In November 2014, ALP filed a GTA requesting the Alberta Utilities Commission ("AUC") to approve revenue requirements of C$811 million for 2015 and C$1.0 billion for 2016, primarily due to continued investment in capital projects as directed by the Alberta Electric System Operator. ALP amended the GTA in June 2015 to propose transmission tariff relief measures for customers and modifications to its capital structure. ALP also amended and updated the GTA in October 2015, reducing the requested revenue requirements to C$672 million for 2015 and C$704 million for 2016. In May 2016, the AUC issued its decision pertaining to the 2015-2016 GTA. ALP filed its 2015-2016 GTA compliance filing in July 2016 to comply with the AUC's decision. The compliance filing requested the AUC to approve revenue requirements of C$599 million for 2015 and C$685 million for 2016. The decreased revenue requirements requested in the compliance filing, as compared to the 2015-2016 GTA filing updated in October 2015, were primarily due to the AUC approval of ALP's proposed immediate tariff relief of C$415 million for customers for 2015 and 2016, through (i) the discontinuance of construction work-in-progress ("CWIP") in rate base and the return to allowance for funds used during construction ("AFUDC") accounting effective January 1, 2015, resulting in a C$82 million reduction of revenue requirement and the refund of C$277 million previously collected as CWIP in rate base as part of ALP's transmission tariffs during 2011-2014 less related returns of C$12 million and (ii) a change to the flow through method for calculating income taxes for 2016, resulting in further tariff relief of C$68 million . Operating revenue for the year ended December 31, 2016, included a one-time reduction of $200 million from the 2015-2016 GTA decision received in May 2016 at ALP. The 2015-2016 GTA decision required ALP to refund $200 million to customers in 2016 through reduced monthly billings for the change from receiving cash during construction for the return on CWIP in rate base to recording allowance for borrowed and equity funds used during construction related to construction expenditures during the 2011 to 2014 time period. This amount is offset with higher capitalized interest and allowance for equity funds in the Consolidated Statements of Operations. In addition, the decision required ALP to change to the flow through method of recognizing income tax expense effective January 1, 2016. This change reduced operating revenue by $45 million for the year ended December 31, 2016, with offsetting impacts to income tax expense in the Consolidated Statements of Operations.
PacifiCorp [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Matters [Text Block]	Regulatory Matters Regulatory Assets Regulatory assets represent costs that are expected to be recovered in future rates. PacifiCorp's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) N/A $ — $ 421 Employee benefit plans (2) 20 years 418 525 Utah mine disposition (3) Various 156 166 Unamortized contract values 6 years 89 98 Deferred net power costs 1 year 21 33 Unrealized loss on derivative contracts 4 years 101 73 Asset retirement obligation 22 years 100 82 Other Various 176 145 Total regulatory assets $ 1,061 $ 1,543 Reflected as: Current assets $ 31 $ 53 Noncurrent assets 1,030 1,490 Total regulatory assets $ 1,061 $ 1,543 (1) Amount primarily represents income tax benefits and expense related to certain property-related basis differences and other various items that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. (2) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in rates when recognized. (3) Amounts represent regulatory assets established as a result of the Utah mine disposition in 2015 for the net property, plant and equipment not considered probable of disallowance and for the portion of losses associated with the assets held for sale, UMWA 1974 Pension Plan withdrawal and closure costs incurred to date considered probable of recovery. PacifiCorp had regulatory assets not earning a return on investment of $589 million and $1.019 billion as of December 31 , 2017 and 2016 , respectively. Regulatory Liabilities Regulatory liabilities represent income to be recognized or amounts to be returned to customers in future periods. PacifiCorp's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Cost of removal (1) 26 years $ 955 $ 917 Deferred income taxes (2) Various 1,960 9 Other Various 156 106 Total regulatory liabilities $ 3,071 $ 1,032 Reflected as: Current liabilities $ 75 $ 54 Noncurrent liabilities 2,996 978 Total regulatory liabilities $ 3,071 $ 1,032 (1) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost. (2) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 8 for further discussion of 2017 Tax Reform. Utah Mine Disposition In December 2014, PacifiCorp filed an advice letter with the California Public Utility Commission (" CPUC ") to request approval to sell certain Utah mining assets and to establish memorandum accounts to track the costs associated with the Utah Mine Disposition for future recovery. In July 2015, the CPUC Energy Division issued a letter requiring PacifiCorp to file a formal application for approval of the sale of certain Utah mining assets. Accordingly, in September 2015, PacifiCorp filed an application with the CPUC . On February 6, 2017, a joint motion was filed with the CPUC seeking approval of a settlement agreement reached by PacifiCorp and all other parties. The agreement states, among other things, that the decision to sell certain Utah mining assets is in the public interest. Parties also reserve their rights to additional testimony, briefs, and hearings to the extent the CPUC determines that additional California Environmental Quality Act proceedings are necessary. A CPUC decision on the joint motion and settlement agreement is expected in 2018.
MidAmerican Energy Company [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Matters [Text Block]	Regulatory Matters Regulatory assets represent costs that are expected to be recovered in future regulated rates. MidAmerican Energy's regulatory assets reflected on the Balance Sheets consist of the following as of December 31 (in millions): Average Remaining Life 2017 2016 Deferred income taxes, net (1) N/A $ — $ 985 Asset retirement obligations (2) 10 years 133 105 Employee benefit plans (3) 13 years 38 40 Unrealized loss on regulated derivative contracts 1 year 6 2 Other Various 27 29 Total $ 204 $ 1,161 (1) Amounts primarily represent income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. (2) Amount predominantly relates to asset retirement obligations for fossil-fueled and wind-powered generating facilities. Refer to Note 12 for a discussion of asset retirement obligations. (3) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized. MidAmerican Energy had regulatory assets not earning a return on investment of $200 million and $1.2 billion as of December 31, 2017 and 2016 , respectively. Regulatory liabilities represent income to be recognized or amounts to be returned to customers in future periods. MidAmerican Energy's regulatory liabilities reflected on the Balance Sheets consist of the following as of December 31 (in millions): Average Remaining Life 2017 2016 Cost of removal accrual (1) 28 years $ 688 $ 665 Deferred income taxes (2) 28 years 681 — Asset retirement obligations (3) 35 years 173 117 Employee benefit plans (4) 11 years 41 12 Pre-funded AFUDC on transmission MVPs (5) 55 years 35 35 Iowa electric revenue sharing accrual (6) 1 year 26 30 Unrealized gain on regulated derivative contracts 1 year 3 6 Other Various 14 18 Total $ 1,661 $ 883 (1) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing utility plant in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost. (2) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts. (3) Amount predominantly represents the excess of nuclear decommission trust assets over the related asset retirement obligation. Refer to Note 12 for a discussion of asset retirement obligations. (4) Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized. (5) Represents AFUDC accrued on transmission MVPs that is deducted from rate base as a result of the inclusion of related construction work-in-progress in rate base. (6) Represents current-year accruals under a regulatory arrangement in Iowa in which equity returns exceeding specified thresholds reduce utility plant upon final determination.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Matters [Text Block]	Regulatory Matters Refer to Note 6 of MidAmerican Energy's Notes to Financial Statements.
Nevada Power Company [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Matters [Text Block]	Regulatory Matters Regulatory assets represent costs that are expected to be recovered in future rates. Nevada Power 's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Decommissioning costs 6 years $ 231 $ 114 Deferred operating costs 12 years 169 127 Merger costs from 1999 merger 27 years 130 136 Employee benefit plans (1) 8 years 89 105 Asset retirement obligations 7 years 72 74 Abandoned projects 3 years 58 75 Legacy meters 15 years 56 60 ON Line deferrals 36 years 47 44 Deferred energy costs 2 years 46 46 Deferred income taxes (2) N/A — 141 Other Various 71 98 Total regulatory assets $ 969 $ 1,020 Reflected as: Current assets $ 28 $ 20 Other assets 941 1,000 Total regulatory assets $ 969 $ 1,020 (1) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized. (2) Amounts primarily represent income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. Nevada Power had regulatory assets not earning a return on investment of $363 million and $560 million as of December 31 , 2017 and 2016 , respectively. The regulatory assets not earning a return on investment primarily consist of merger costs from the 1999 merger, asset retirement obligations, deferred operating costs, a portion of the employee benefit plans, losses on reacquired debt and deferred energy costs. Regulatory assets not earning a return as of December 31, 2016 also included deferred income taxes. Regulatory liabilities represent amounts to be returned to customers in future periods. Nevada Power 's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) 33 years $ 670 $ 9 Cost of removal (2) 31 years 307 294 Impact fees 6 years 89 90 Energy efficiency program 1 year 27 37 Other Various 28 23 Total regulatory liabilities $ 1,121 $ 453 Reflected as: Current liabilities $ 91 $ 37 Other long-term liabilities 1,030 416 Total regulatory liabilities $ 1,121 $ 453 (1) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts. (2) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost. Deferred Energy Nevada statutes permit regulated utilities to adopt deferred energy accounting procedures. The intent of these procedures is to ease the effect on customers of fluctuations in the cost of purchased natural gas, fuel and electricity and are subject to annual prudency review by the PUCN. Under deferred energy accounting, to the extent actual fuel and purchased power costs exceed fuel and purchased power costs recoverable through current rates that excess is not recorded as a current expense on the Consolidated Statements of Operations but rather is deferred and recorded as a regulatory asset on the Consolidated Balance Sheets and would be included in the table above as deferred energy costs. Conversely, a regulatory liability is recorded to the extent fuel and purchased power costs recoverable through current rates exceed actual fuel and purchased power costs and is included in the table above as deferred energy costs. These excess amounts are reflected in quarterly adjustments to rates and recorded as cost of fuel, energy and capacity in future time periods. Regulatory Rate Review In June 2017, Nevada Power filed an electric regulatory rate review with the PUCN. The filing supported an annual revenue increase of $29 million , or 2% , but requested no incremental annual revenue relief. In December 2017, the PUCN issued an order which reduced Nevada Power's revenue requirement by $26 million and requires Nevada Power to share 50% of revenues related to equity returns above 9.7% . As a result of the order, Nevada Power recorded expense of $28 million primarily due to the reduction of a regulatory asset to return to customers revenue collected for costs not incurred. In January 2018, Nevada Power filed a petition for clarification of certain findings and directives in the order. The new rates were effective in February 2018. Energy Efficiency Program Rates ("EEPR") and Energy Efficiency Implementation Rates ("EEIR") EEPR was established to allow Nevada Power to recover the costs of implementing energy efficiency programs and EEIR was established to offset the negative impacts on revenue associated with the successful implementation of energy efficiency programs. These rates change once a year in the utility's annual DEAA application based on energy efficiency program budgets prepared by Nevada Power and approved by the PUCN in integrated resource plan proceedings. To the extent Nevada Power 's earned rate of return exceeds the rate of return used to set base general rates, Nevada Power is required to refund to customers EEIR revenue previously collected for that year. In March 2017, Nevada Power filed an application to reset the EEIR and EEPR and refund the EEIR revenue received in 2016, including carrying charges. In September 2017, the PUCN issued an order accepting a stipulation requiring Nevada Power to refund the 2016 revenue and reset the rates as filed effective October 1, 2017. The EEIR liability for Nevada Power is $10 million , which is included in current regulatory liabilities on the Consolidated Balance Sheets as of December 31 , 2017 and 2016 . Chapter 704B Applications Chapter 704B of the Nevada Revised Statutes allows retail electric customers with an average annual load of one megawatt ("MW") or more to file with the PUCN an application to purchase energy from alternative providers of a new electric resource and become distribution only service customers. On a case-by-case basis, the PUCN will assess the application and may deny or grant the application subject to conditions, including paying an impact fee, paying on-going charges and receiving approval for specific alternative energy providers and terms. The impact fee and on-going charges are assessed to alleviate the burden on other Nevada customers for the applicant's share of previously committed investments and long-term renewable contracts and are set at a level designed such that the remaining customers are not subjected to increased costs. In May 2015, MGM Resorts International ("MGM") and Wynn Las Vegas, LLC ("Wynn"), filed applications with the PUCN to purchase energy from alternative providers of a new electric resource and become distribution only service customers of Nevada Power. In December 2015, the PUCN granted the applications subject to conditions, including paying an impact fee, on-going charges and receiving approval for specific alternative energy providers and terms. In December 2015, the applicants filed petitions for reconsideration. In January 2016, the PUCN granted reconsideration and updated some of the terms, including removing a limitation related to energy purchased indirectly from NV Energy. In September 2016, MGM and Wynn paid impact fees of $82 million and $15 million , respectively. In October 2016, MGM and Wynn became distribution only service customers and started procuring energy from another energy supplier. In April 2017, Wynn filed a motion with the PUCN seeking relief from the January 2016 order and requested the PUCN adopt an alternative impact fee and revise on-going charges associated with retirement of assets and high cost renewable contracts. This request is still pending. In May 2017, a stipulation reached between MGM, Regulatory Operations Staff and the Bureau of Consumer Protection was filed requiring Nevada Power to reduce the original $82 million impact fee by $16 million and apply the credit against MGM's remaining on-going charge obligation. In June 2017, the PUCN approved the stipulation as filed. In September 2016, Switch, Ltd. ("Switch"), a customer of Nevada Power, filed an application with the PUCN to purchase energy from alternative providers of a new electric resource and become a distribution only service customer of Nevada Power. In December 2016, the PUCN approved a stipulation agreement that allows Switch to purchase energy from alternative providers subject to conditions , including paying an impact fee to Nevada Power. In May 2017, Switch paid impact fees of $27 million and, in June 2017, Switch became a distribution only service customer and started procuring energy from another energy supplier. In November 2016, Caesars Enterprise Service ("Caesars"), a customer of Nevada Power, filed an application with the PUCN to purchase energy from alternative providers of a new electric resource and become a distribution only service customer of Nevada Power. In March 2017, the PUCN approved the application allowing Caesars to purchase energy from alternative providers subject to conditions, including paying an impact fee. In March 2017, Caesars provided notice that it intends to pay the impact fee monthly for six years and proceed with purchasing energy from alternative providers. In July 2017, Caesars made the required compliance filings and, in September 2017, the PUCN issued an order allowing Caesars to acquire electric energy and ancillary services from another energy supplier and become a distribution only service customer of Nevada Power. In December 2017, Caesars provided notice that it intends to transition eligible meters in the Nevada Power service territory to unbundled electric service in February 2018 at the earliest. Emissions Reduction and Capacity Retirement Plan ("ERCR Plan") In March 2017, Nevada Power retired Reid Gardner Unit 4, a 257 -MW coal-fueled generating facility. The early retirement was approved by the PUCN in December 2016 as a part of Nevada Power's second amendment to the ERCR Plan. The remaining net book value of $151 million was moved from property, plant and equipment, net to noncurrent regulatory assets on the Consolidated Balance Sheet in March 2017, in compliance with the ERCR Plan. Refer to Note 14 for additional information on the ERCR Plan.
Sierra Pacific Power Company [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Matters [Text Block]	Regulatory Matters Regulatory assets represent costs that are expected to be recovered in future rates. Sierra Pacific 's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Employee benefit plans (1) 8 years $ 110 $ 128 Merger costs from 1999 merger 29 years 77 80 Abandoned projects 7 years 34 39 Renewable energy programs 2 years 23 25 Losses on reacquired debt 16 years 21 22 Deferred income taxes (2) N/A — 85 Other Various 67 56 Total regulatory assets $ 332 $ 435 Reflected as: Current assets $ 32 $ 25 Other assets 300 410 Total regulatory assets $ 332 $ 435 (1) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized. (2) Amounts represent income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. Sierra Pacific had regulatory assets not earning a return on investment of $188 million and $305 million as of December 31 , 2017 and 2016 , respectively. The regulatory assets not earning a return on investment primarily consist of merger costs from the 1999 merger, a portion of the employee benefit plans, losses on reacquired debt, asset retirement obligations and legacy meters. Regulatory assets not earning a return as of December 31, 2016 also included deferred income taxes. Regulatory liabilities represent amounts to be returned to customers in future periods. Sierra Pacific 's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) 29 years $ 264 $ 6 Cost of removal (2) 41 years 211 205 Deferred energy costs 2 years 8 64 Other Various 17 15 Total regulatory liabilities $ 500 $ 290 Reflected as: Current liabilities $ 19 $ 69 Other long-term liabilities 481 221 Total regulatory liabilities $ 500 $ 290 (1) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 9 for further discussion of 2017 Tax Reform impacts. (2) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost. Deferred Energy Nevada statutes permit regulated utilities to adopt deferred energy accounting procedures. The intent of these procedures is to ease the effect on customers of fluctuations in the cost of purchased natural gas, fuel and electricity and are subject to annual prudency review by the PUCN. Under deferred energy accounting, to the extent actual fuel and purchased power costs exceed fuel and purchased power costs recoverable through current rates that excess is not recorded as a current expense on the Consolidated Statements of Operations but rather is deferred and recorded as a regulatory asset on the Consolidated Balance Sheets and would be included in the table above as deferred energy costs. Conversely, a regulatory liability is recorded to the extent fuel and purchased power costs recoverable through current rates exceed actual fuel and purchased power costs and is included in the table above as deferred energy costs. These excess amounts are reflected in quarterly adjustments to rates and recorded as cost of fuel, energy and capacity in future time periods. Regulatory Rate Review In June 2016, Sierra Pacific filed an electric regulatory rate review with the PUCN. The filing requested no incremental annual revenue relief. In October 2016, Sierra Pacific filed with the PUCN a settlement agreement resolving most, but not all, issues in the proceeding and reduced Sierra Pacific's electric revenue requirement by $3 million spread evenly to all rate classes. In December 2016, the PUCN approved the settlement agreement and established an additional six MW of net metering capacity under the grandfathered rates, which are those net metering rates that were in effect prior to January 2016; the order establishes cost-based rates and a value-based excess energy credit for customers who choose to install private generation after the six MW limitation is reached. The new rates were effective January 1, 2017. In January 2017, Sierra Pacific filed a petition for reconsideration relating to the creation of the additional six MW of net metering at the grandfathered rates. Sierra Pacific believes the effects of the PUCN decision results in additional cost shifting to non-net metering customers and reduces the stipulated rate reduction for other customer classes. In June 2017, the PUCN denied the petition for reconsideration. In June 2016, Sierra Pacific filed a gas regulatory rate review with the PUCN. The filing requested a slight decrease in its incremental annual revenue requirement. In October 2016, Sierra Pacific filed with the PUCN a settlement agreement resolving all issues in the proceeding and reduced Sierra Pacific's gas revenue requirement by $2 million . In December 2016, the PUCN approved the settlement agreement. The new rates were effective January 1, 2017. Energy Efficiency Program Rates ("EEPR") and Energy Efficiency Implementation Rates ("EEIR") EEPR was established to allow Sierra Pacific to recover the costs of implementing energy efficiency programs and EEIR was established to offset the negative impacts on revenue associated with the successful implementation of energy efficiency programs. These rates change once a year in the utility's annual DEAA application based on energy efficiency program budgets prepared by Sierra Pacific and approved by the PUCN in integrated resource plan proceedings. To the extent Sierra Pacific 's earned rate of return exceeds the rate of return used to set base general rates, Sierra Pacific is required to refund to customers EEIR revenue previously collected for that year. In March 2017, Sierra Pacific filed an application to reset the EEIR and EEPR . In September 2017, the PUCN issued an order accepting a stipulation to reset the rates as filed effective October 1, 2017. The EEIR liability for Sierra Pacific is $1 million and $2 million , which is included in current regulatory liabilities on the Consolidated Balance Sheets as of December 31 , 2017 and 2016 , respectively. Chapter 704B Applications Chapter 704B of the Nevada Revised Statutes allows retail electric customers with an average annual load of one megawatt ("MW") or more to file with the PUCN an application to purchase energy from alternative providers of a new electric resource and become distribution only service customers. On a case-by-case basis, the PUCN will assess the application and may deny or grant the application subject to conditions, including paying an impact fee, paying on-going charges and receiving approval for specific alternative energy providers and terms. The impact fee and on-going charges are assessed to alleviate the burden on other Nevada customers for the applicant's share of previously committed investments and long-term renewable contracts and are set at a level designed such that the remaining customers are not subjected to increased costs. In September 2016, Switch, Ltd. ("Switch"), a customer of Sierra Pacific , filed an application with the PUCN to purchase energy from alternative providers of a new electric resource and become a distribution only service customer of Sierra Pacific . In December 2016, the PUCN approved a stipulation agreement that allows Switch to purchase energy from alternative providers without paying an impact fee, subject to conditions . In June 2017, Switch became a distribution only service customer and started procuring energy from another energy supplier. In November 2016, Caesars Enterprise Service ("Caesars"), a customer of Sierra Pacific , filed an application with the PUCN to purchase energy from alternative providers of a new electric resource and become a distribution only service customer of Sierra Pacific . In March 2017, the PUCN approved the application allowing Caesars to purchase energy from alternative providers subject to conditions, including paying an impact fee. In March 2017, Caesars provided notice that it intends to pay the impact fee monthly for three years and proceed with purchasing energy from alternative providers. In July 2017, Caesars made the required compliance filings and, in September 2017, the PUCN issued an order allowing Caesars to acquire electric energy and ancillary services from another energy supplier and become a distribution only service customer of Sierra Pacific . In January 2018, Caesars became a distribution only service customer and started procuring energy from another energy supplier for its eligible meters in the Sierra Pacific service territory. In May 2017, Peppermill Resort Spa Casino ("Peppermill"), a customer of Sierra Pacific, filed an application with the PUCN to purchase energy from alternative providers of a new electric resource and become a distribution only service customer of Sierra Pacific. In August 2017, the PUCN approved a stipulation allowing Peppermill to purchase energy from alternative providers subject to conditions, including paying an impact fee. In September 2017, Peppermill provided notice that it intends to pay the impact fee and proceed with purchasing energy from alternative providers.

Investments and Restricted Cash

Investments and Restricted Cash and Investments (Notes)	12 Months Ended
	Dec. 31, 2017
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Investments and Restricted Cash and Investments [Text Block]	Investments and Restricted Cash and Investments Investments and restricted cash and investments consists of the following as of December 31 (in millions): 2017 2016 Investments: BYD Company Limited common stock $ 1,961 $ 1,185 Rabbi trusts 441 403 Other 124 106 Total investments 2,526 1,694 Equity method investments: Tax equity investments 1,025 741 Electric Transmission Texas, LLC 524 672 Bridger Coal Company 137 165 Other 148 142 Total equity method investments 1,834 1,720 Restricted cash and investments: Quad Cities Station nuclear decommissioning trust funds 515 460 Other 348 282 Total restricted cash and investments 863 742 Total investments and restricted cash and investments $ 5,223 $ 4,156 Reflected as: Current assets $ 351 $ 211 Noncurrent assets 4,872 3,945 Total investments and restricted cash and investments $ 5,223 $ 4,156 Investments BHE's investment in BYD Company Limited common stock is accounted for as an available-for-sale security with changes in fair value recognized in AOCI. Upon adoption of ASU No. 2016-01 effective January 1, 2018, all changes in fair value (whether realized or unrealized) will be recognized as gains or losses in the Consolidated Statements of Operations with a cumulative-effect increase to retained earnings as of the date of adoption totaling $1,085 million . The fair value of BHE's investment in BYD Company Limited common stock reflects a pre-tax unrealized gain of $1,729 million and $953 million as of December 31, 2017 and 2016 , respectively. Rabbi trusts primarily hold corporate-owned life insurance on certain current and former key executives and directors. The Rabbi trusts were established to hold investments used to fund the obligations of various nonqualified executive and director compensation plans and to pay the costs of the trusts. The amount represents the cash surrender value of all of the policies included in the Rabbi trusts, net of amounts borrowed against the cash surrender value. Equity Method Investments The Company has invested in projects sponsored by third parties, commonly referred to as tax equity investments. Under the terms of these tax equity investments, the Company has entered into equity capital contribution agreements with the project sponsors that require contributions. The Company has made contributions of $403 million , $584 million and $170 million in 2017 , 2016 and 2015 , respectively, pursuant to these equity capital contribution agreements as the various projects achieve commercial operation. Once a project achieves commercial operation, the Company enters into a partnership agreement with the project sponsor that directs and allocates the operating profits and tax benefits from the project. BHE , through a subsidiary, owns 50% of Electric Transmission Texas, LLC , which owns and operates electric transmission assets in the Electric Reliability Council of Texas footprint. BHE , through a subsidiary, owns 66.67% of Bridger Coal Company ("Bridger Coal"), which is a coal mining joint venture that supplies coal to the Jim Bridger Nos. 1-4 generating facility. Bridger Coal is being accounted for under the equity method of accounting as the power to direct the activities that most significantly impact Bridger Coal's economic performance are shared with the joint venture partner. See Note 11 for discussion of 2017 Tax Reform impacts to equity earnings recorded for the year ending December 31, 2017. Restricted Cash and Investments MidAmerican Energy has established a trust for the investment of funds for decommissioning the Quad Cities Nuclear Station Units 1 and 2 ("Quad Cities Station"). These investments in debt and equity securities are classified as available-for-sale and are reported at fair value. Funds are invested in the trust in accordance with applicable federal and state investment guidelines and are restricted for use as reimbursement for costs of decommissioning the Quad Cities Station, which are currently licensed for operation until December 2032.
MidAmerican Energy Company [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Investments and Restricted Cash and Investments [Text Block]	Investments and Restricted Cash and Investments Investments and restricted cash and investments consists of the following amounts as of December 31 (in millions): 2017 2016 Nuclear decommissioning trust $ 515 $ 460 Rabbi trusts 198 184 Other 15 9 Total $ 728 $ 653 MidAmerican Energy has established a trust for the investment of funds for decommissioning the Quad Cities Station. These investments in debt and equity securities are classified as available-for-sale and are reported at fair value. Funds are invested in the trust in accordance with applicable federal and state investment guidelines and are restricted for use as reimbursement for costs of decommissioning the Quad Cities Station, which is currently licensed for operation until December 2032. As of December 31, 2017 and 2016 , the fair value of the trust's funds was invested as follows: 56% and 54% , respectively, in domestic common equity securities, 34% and 35% , respectively, in United States government securities, 7% and 8% , respectively, in domestic corporate debt securities and 3% and 3% , respectively, in other securities. Rabbi trusts primarily hold corporate-owned life insurance on certain current and former key executives and directors. The Rabbi trusts were established to hold investments used to fund the obligations of various nonqualified executive and director compensation plans and to pay the costs of the trusts. The amount represents the cash surrender value of all of the policies included in the Rabbi trusts, net of amounts borrowed against the cash surrender value. Changes in the cash surrender value of the policies are reflected in other income and (expense) - other, net on the Statements of Operation.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Investments and Restricted Cash and Investments [Text Block]	Investments and Restricted Cash and Investments Refer to Note 7 of MidAmerican Energy's Notes to Financial Statements in Item 8 of this Form 10-K. In addition to MidAmerican Energy's investments and restricted cash and investments, MHC had corporate-owned life insurance policies in a Rabbi trust owned by MHC with a total cash surrender value of $2 million as of December 31, 2017 and 2016 .

Short-Term Debt and Credit Faci

Short-Term Debt and Credit Facilities (Notes)	12 Months Ended
	Dec. 31, 2017
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Short-Term Debt and Credit Facilities The following table summarizes BHE's and its subsidiaries' availability under their credit facilities as of December 31 (in millions): MidAmerican NV Northern BHE PacifiCorp Funding Energy Powergrid AltaLink Other Total (1) 2017: Credit facilities (2) $ 3,600 $ 1,000 $ 909 $ 650 $ 203 $ 1,054 $ 1,635 $ 9,051 Less: Short-term debt (3,331 ) (80 ) — — — (345 ) (732 ) (4,488 ) Tax-exempt bond support and letters of credit (7 ) (130 ) (370 ) (80 ) — (7 ) — (594 ) Net credit facilities $ 262 $ 790 $ 539 $ 570 $ 203 $ 702 $ 903 $ 3,969 2016: Credit facilities $ 2,000 $ 1,000 $ 609 $ 650 $ 185 $ 986 $ 915 $ 6,345 Less: Short-term debt (834 ) (270 ) (99 ) — — (289 ) (377 ) (1,869 ) Tax-exempt bond support and letters of credit (7 ) (142 ) (220 ) (80 ) — (8 ) — (457 ) Net credit facilities $ 1,159 $ 588 $ 290 $ 570 $ 185 $ 689 $ 538 $ 4,019 (1) The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method. (2) Includes amounts borrowed on a short-term loan totaling $600 million at BHE that was repaid in full in January 2018. As of December 31, 2017 , the Company was in compliance with the covenants of its credit facilities and letter of credit arrangements. BHE BHE has a $2.0 billion unsecured credit facility expiring in June 2020 with a one-year extension option subject to lender consent and a $1.0 billion unsecured credit facility expiring in May 2018 . These credit facilities, which are for general corporate purposes and also support BHE's commercial paper program and provide for the issuance of letters of credit, have variable interest rates based on the Eurodollar rate or a base rate, at BHE's option, plus a spread that varies based on BHE's credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 1.74% and 0.88% , respectively. These credit facilities require that BHE's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.70 to 1.0 as of the last day of each quarter. As of December 31, 2017 and 2016 , BHE had $96 million and $123 million , respectively, of letters of credit outstanding, of which $7 million as of December 31, 2017 and 2016 were issued under the credit facilities. These letters of credit primarily support power purchase agreements and debt service requirements at certain subsidiaries of BHE Renewables, LLC expiring through December 2018 and have provisions that automatically extend the annual expiration dates for an additional year unless the issuing bank elects not to renew a letter of credit prior to the expiration date. As of December 31, 2017, BHE had a $600 million term loan outstanding expiring in June 2018. The term loan had a variable interest rate based on the Eurodollar rate, plus a fixed spread, or a base rate, at BHE's option. In January 2018, BHE repaid the term loan at par plus accrued interest. As of December 31, 2017, the interest rate on the outstanding term loan was 2.27% . PacifiCorp PacifiCorp has a $600 million unsecured credit facility expiring in June 2020 with two one-year extension options subject to lender consent and a $400 million unsecured credit facility expiring in June 2020 with a one-year extension option subject to lender consent. These credit facilities, which support PacifiCorp's commercial paper program, certain series of its tax-exempt bond obligations and provide for the issuance of letters of credit, have variable interest rates based on the Eurodollar rate or a base rate, at PacifiCorp's option, plus a spread that varies based on PacifiCorp's credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 1.83% and 0.96% , respectively. These credit facilities require that PacifiCorp's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. As of December 31, 2017 and 2016 , PacifiCorp had $230 million and $269 million , respectively, of fully available letters of credit issued under committed arrangements. As of December 31, 2017 and 2016 , $216 million and $255 million , respectively, of these letters of credit support PacifiCorp's variable-rate tax-exempt bond obligations and expire through March 2019 and $14 million support certain transactions required by third parties and have provisions that automatically extend the annual expiration dates for an additional year unless the issuing bank elects not to renew a letter of credit prior to the expiration date. MidAmerican Funding MidAmerican Energy has a $900 million unsecured credit facility expiring in June 2020 with two one-year extension options subject to lender consent. The credit facility, which supports MidAmerican Energy's commercial paper program and its variable-rate tax-exempt bond obligations and provides for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at MidAmerican Energy's option, plus a spread that varies based on MidAmerican Energy's credit ratings for senior unsecured long-term debt securities. As of December 31, 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 0.73% . The credit facility requires that MidAmerican Energy's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. NV Energy Nevada Power has a $400 million secured credit facility expiring in June 2020 and Sierra Pacific has a $250 million secured credit facility expiring in June 2020 each w ith two one-year extension options subject to lender consent. These credit facilities, which are for general corporate purposes and provide for the issuance of letters of credit, have a variable interest rate based on the Eurodollar rate or a base rate, at each of the Nevada Utilities' option, plus a spread that varies based on each of the Nevada Utilities' credit ratings for its senior secured long‑term debt securities. Amounts due under each credit facility are collateralized by each of the Nevada Utilities' general and refunding mortgage bonds. These credit facilities require that each of the Nevada Utilities' ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. Northern Powergrid Northern Powergrid has a £150 million unsecured credit facility expiring in April 2020. The credit facility has a variable interest rate based on sterling London Interbank Offered Rate ("LIBOR") plus a spread that varies based on its credit ratings. The credit facility requires that the ratio of consolidated senior total net debt, including current maturities, to regulated asset value not exceed 0.8 to 1.0 at Northern Powergrid and 0.65 to 1.0 at Northern Powergrid (Northeast) Limited and Northern Powergrid (Yorkshire) plc as of June 30 and December 31. Northern Powergrid 's interest coverage ratio shall not be less than 2.5 to 1.0. AltaLink ALP has a C$750 million secured revolving credit facility expiring in December 2019 with a recurring one-year extension option subject to lender consent. The credit facility, which provides support for borrowings under the unsecured commercial paper program and may also be used for general corporate purposes, has a variable interest rate based on the Canadian bank prime lending rate or a spread above the Bankers' Acceptance rate, at ALP 's option, based on ALP 's credit ratings for its senior secured long-term debt securities. In addition, ALP has a C$75 million secured revolving credit facility expiring in December 2019 with a recurring one-year extension option subject to lender consent. The credit facility, which may be used for general corporate purposes and letters of credit, has a variable interest rate based on the Canadian bank prime lending rate, United States base rate, a spread above the United States LIBOR loan rate or a spread above the Bankers' Acceptance rate, at ALP 's option, based on ALP 's credit ratings for its senior secured long-term debt securities. At the renewal date, ALP has the option to convert these facilities to one-year term facilities. As of December 31, 2017 and 2016 , ALP had $121 million and $26 million outstanding under these facilities at a weighted average interest rate of 1.42% and 0.99% , respectively. The credit facilities require the consolidated indebtedness to total capitalization not exceed 0.75 to 1.0 measured as of the last day of each quarter. AltaLink Investments, L.P. has a C$300 million unsecured revolving term credit facility expiring in December 2022 and a C$200 million unsecured revolving credit facility expiring in December 2018 each with a recurring one-year extension option subject to lender consent. The credit facilities, which may be used for general corporate purposes and letters of credit to a maximum of C$10 million , have a variable interest rate based on the Canadian bank prime lending rate, United States base rate, a spread above the United States LIBOR loan rate or a spread above the Bankers' Acceptance rate, at AltaLink Investments, L.P.'s option, based on AltaLink Investments, L.P.'s credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , AltaLink Investments, L.P. had $224 million and $263 million outstanding under these facilities at a weighted average interest rate of 2.40% and 1.74% , respectively. The credit facilities require the consolidated total debt to capitalization to not exceed 0.8 to 1.0 and earnings before interest, taxes, depreciation and amortization to interest expense for the four fiscal quarters ended to not be less than 2.25 to 1.0 measured as of the last day of each quarter. HomeServices HomeServices has a $600 million unsecured credit facility expiring in September 2022. The credit facility, which is for general corporate purposes and provides for the issuance of letters of credit, has a variable interest rate based on the LIBOR or a base rate, at HomeServices' option, plus a spread that varies based on HomeServices' total net leverage ratio as of the last day of each quarter. As of December 31, 2017 and 2016 , HomeServices had $292 million and $50 million , respectively, outstanding under its credit facility with a weighted average interest rate of 2.75% and 1.77% , respectively. Through its subsidiaries, HomeServices maintains mortgage lines of credit totaling $1.0 billion and $565 million as of December 31, 2017 and 2016 , respectively, used for mortgage banking activities that expire beginning in January 2018 through December 2018 or are due on demand. The mortgage lines of credit have variable rates based on LIBOR plus a spread. Collateral for these credit facilities is comprised of residential property being financed and is equal to the loans funded with the facilities. As of December 31, 2017 and 2016 , HomeServices had $440 million and $327 million , respectively, outstanding under these mortgage lines of credit at a weighted average interest rate of 3.60% and 2.77% , respectively. BHE Renewables Letters of Credit In connection with their bond offerings, Topaz and Solar Star entered into separate letter of credit and reimbursement facilities totaling $435 million and $627 million as of December 31, 2017 and 2016 . Letters of credit issued under the letter of credit facilities will be used to (a) provide security under the power purchase agreement and large generator interconnection agreements, (b) fund the debt service reserve requirement and the operation and maintenance debt service reserve requirement and (c) provide security for remediation and mitigation liabilities. As of December 31, 2017 and 2016 , $357 million and $599 million , respectively, of letters of credit had been issued under these facilities. As of December 31, 2017 and 2016 , certain other renewable projects collectively have letters of credit outstanding of $118 million and $106 million , respectively, primarily in support of the power purchase agreements associated with the projects.
PacifiCorp [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Short-term Debt and Other Financing Agreements The following table summarizes PacifiCorp's availability under its credit facilities as of December 31 (in millions): 2017: Credit facilities $ 1,000 Less: Short-term debt (80 ) Tax-exempt bond support (130 ) Net credit facilities $ 790 2016: Credit facilities $ 1,000 Less: Short-term debt (270 ) Tax-exempt bond support (142 ) Net credit facilities $ 588 PacifiCorp has a $600 million unsecured credit facility expiring in June 2020 with two one-year extension options subject to lender consent and a $400 million unsecured credit facility expiring in June 2020 with a one-year extension option subject to lender consent. These credit facilities, which support PacifiCorp's commercial paper program, certain series of its tax-exempt bond obligations and provide for the issuance of letters of credit, have variable interest rates based on the Eurodollar rate or a base rate, at PacifiCorp's option, plus a spread that varies based on PacifiCorp's credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 1.83% and 0.96% , respectively. These credit facilities require that PacifiCorp's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. As of December 31, 2017 and 2016 , PacifiCorp had $230 million and $269 million , respectively, of fully available letters of credit issued under committed arrangements. As of December 31, 2017 and 2016 , $216 million and $255 million , respectively, of these letters of credit, support PacifiCorp's variable-rate tax-exempt bond obligations and expire through March 2019 and $14 million support certain transactions required by third parties and have provisions that automatically extend the annual expiration dates for an additional year unless the issuing bank elects not to renew a letter of credit prior to the expiration date.
MidAmerican Energy Company [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Short-Term Debt and Credit Facilities Interim financing of working capital needs and the construction program is obtained from unaffiliated parties through the sale of commercial paper or short-term borrowing from banks. MidAmerican Energy has a $900 million unsecured credit facility expiring June 2020 with two one-year extension options subject to lender consent. The credit facility, which supports MidAmerican Energy's commercial paper program and its variable-rate tax-exempt bond obligations and provides for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at MidAmerican Energy's option, plus a spread that varies based on MidAmerican Energy's credit ratings for senior unsecured long-term debt securities. In addition, MidAmerican Energy has a $5 million unsecured credit facility, which expires in June 2018 and has a variable interest rate based on LIBOR plus a spread. As of December 31, 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 0.73% . The $900 million credit facility requires that MidAmerican Energy's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of any quarter. As of December 31, 2017 , MidAmerican Energy was in compliance with the covenants of its credit facilities. MidAmerican Energy has authority from the FERC to issue commercial paper and bank notes aggregating $905 million through February 28, 2019. The following table summarizes MidAmerican Energy's availability under its two unsecured revolving credit facilities as of December 31 (in millions): 2017 2016 Credit facilities $ 905 $ 605 Less: Short-term debt outstanding — (99 ) Variable-rate tax-exempt bond support (370 ) (220 ) Net credit facilities $ 535 $ 286
MidAmerican Funding, LLC and Subsidiaries [Domain]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Short-Term Debt and Credit Facilities Refer to Note 8 of MidAmerican Energy's Notes to Financial Statements. In addition to MidAmerican Energy's credit facilities, MHC has a $4 million unsecured credit facility, which expires in June 2018 and has a variable interest rate based on LIBOR plus a spread. As of December 31, 2017 and 2016 , there were no borrowings outstanding under this credit facility. As of December 31, 2017 , MHC was in compliance with the covenants of its credit facility.
Nevada Power Company [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Credit Facility Nevada Power has a $400 million secured credit facility expiring in June 2020 w ith two one-year extension options subject to lender consent. The credit facility, which is for general corporate purposes and provide for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at Nevada Power 's option, plus a spread that varies based on Nevada Power 's credit ratings for its senior secured long‑term debt securities. As of December 31 , 2017 and 2016 , Nevada Power had no borrowings outstanding under the credit facility. Amounts due under Nevada Power 's credit facility are collateralized by Nevada Power 's general and refunding mortgage bonds. The credit facility requires Nevada Power 's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter.
Sierra Pacific Power Company [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Credit Facility The following table summarizes Sierra Pacific's availability under its credit facilities as of December 31 (in millions): 2017 2016 Credit facilities $ 250 $ 250 Less - Water Facilities Refunding Revenue Bond support (80 ) (80 ) Net credit facilities $ 170 $ 170 Sierra Pacific has a $250 million secured credit facility expiring in June 2020 with two one-year extension options subject to lender consent. The credit facility, which is for general corporate purposes and provides for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at Sierra Pacific 's option, plus a spread that varies based on Sierra Pacific 's credit ratings for its senior secured long‑term debt securities. As of December 31 , 2017 and 2016 , Sierra Pacific had no borrowings outstanding under the credit facility. Amounts due under Sierra Pacific 's credit facility are collateralized by Sierra Pacific 's general and refunding mortgage bonds. The credit facility requires Sierra Pacific 's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter.

BHE Debt (Notes)

BHE Debt (Notes)	12 Months Ended
	Dec. 31, 2017
MEHC Debt [Abstract]
BHE Debt [Text Block]	BHE Debt Senior Debt BHE senior debt represents unsecured senior obligations of BHE that are redeemable in whole or in part at any time generally with make-whole premiums. BHE senior debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (in millions): Par Value 2017 2016 1.10% Senior Notes, due 2017 $ — $ — $ 400 5.75% Senior Notes, due 2018 650 650 649 2.00% Senior Notes, due 2018 350 350 349 2.40% Senior Notes, due 2020 350 349 349 3.75% Senior Notes, due 2023 500 498 497 3.50% Senior Notes, due 2025 400 398 397 8.48% Senior Notes, due 2028 301 302 477 6.125% Senior Bonds, due 2036 1,670 1,660 1,690 5.95% Senior Bonds, due 2037 550 547 547 6.50% Senior Bonds, due 2037 225 222 987 5.15% Senior Notes, due 2043 750 739 739 4.50% Senior Notes, due 2045 750 737 737 Total BHE Senior Debt $ 6,496 $ 6,452 $ 7,818 Reflected as: Current liabilities $ 1,000 $ 400 Noncurrent liabilities 5,452 7,418 Total BHE Senior Debt $ 6,452 $ 7,818 In January 2018, BHE issued $450 million of its 2.375% Senior Notes due 2021, $400 million of its 2.800% Senior Notes due 2023, $600 million of its 3.250% Senior Notes due 2028 and $750 million of its 3.800% Senior Notes due 2048. The net proceeds were used to refinance a portion of the Company's short-term indebtedness and for general corporate purposes. In December 2017, BHE completed a cash tender offer for a portion of its 8.48% Senior Notes due 2028, 6.50% Senior Notes due 2037 and 6.125% Senior Notes due 2036. The total pre-tax costs of the tender offer of $410 million were recorded in other, net on the Consolidated Statement of Operations. Junior Subordinated Debentures BHE junior subordinated debentures consists of the following as of December 31 (in millions): Par Value 2017 2016 Junior subordinated debentures, due 2044 $ — $ — $ 944 Junior subordinated debentures, due 2057 100 100 — Total BHE junior subordinated debentures - noncurrent $ 100 $ 100 $ 944 During 2017, BHE repaid at par value a total of $944 million , plus accrued interest, of its junior subordinated debentures due December 2044. Interest expense to Berkshire Hathaway for the years ended December 31, 2017 , 2016 and 2015 was $16 million , $65 million and $104 million , respectively. In June 2017, BHE issued $100 million of its 5.00% junior subordinated debentures due June 2057 in exchange for 181,819 shares of BHE no par value common stock held by a minority shareholder. The junior subordinated debentures are redeemable at BHE's option at any time from and after June 15, 2037, at par plus accrued and unpaid interest. Interest expense to the minority shareholder for the year ended December 31, 2017 was $3 million .

Subsidiary Debt (Notes)

Subsidiary Debt (Notes)	12 Months Ended
	Dec. 31, 2017
Debt Instrument [Line Items]
Subsidiary Debt	Subsidiary Debt BHE 's direct and indirect subsidiaries are organized as legal entities separate and apart from BHE and its other subsidiaries. Pursuant to separate financing agreements, substantially all of PacifiCorp's electric utility properties; the equity interest of MidAmerican Funding's subsidiary; MidAmerican Energy's electric utility properties in the state of Iowa; substantially all of Nevada Power's and Sierra Pacific's properties in the state of Nevada AltaLink's transmission properties; and substantially all of the assets of the subsidiaries of BHE Renewables that are direct or indirect owners of solar and wind generation projects are pledged or encumbered to support or otherwise provide the security for their related subsidiary debt. It should not be assumed that the assets of any subsidiary will be available to satisfy BHE 's obligations or the obligations of its other subsidiaries. However, unrestricted cash or other assets which are available for distribution may, subject to applicable law, regulatory commitments and the terms of financing and ring-fencing arrangements for such parties, be advanced, loaned, paid as dividends or otherwise distributed or contributed to BHE or affiliates thereof. The long-term debt of BHE's subsidiaries may include provisions that allow BHE 's subsidiaries to redeem such debt in whole or in part at any time. These provisions generally include make-whole premiums. Distributions at these separate legal entities are limited by various covenants including, among others, leverage ratios, interest coverage ratios and debt service coverage ratios. As of December 31, 2017 , all subsidiaries were in compliance with their long-term debt covenants. Long-term debt of subsidiaries consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (in millions): Par Value 2017 2016 PacifiCorp $ 7,061 $ 7,025 $ 7,079 MidAmerican Funding 5,319 5,259 4,592 NV Energy 4,577 4,581 4,582 Northern Powergrid 2,792 2,805 2,379 BHE Pipeline Group 800 796 990 BHE Transmission 4,348 4,334 4,058 BHE Renewables 3,636 3,594 3,674 HomeServices 247 247 — Total subsidiary debt $ 28,780 $ 28,641 $ 27,354 Reflected as: Current liabilities $ 2,431 $ 606 Noncurrent liabilities 26,210 26,748 Total subsidiary debt $ 28,641 $ 27,354 PacifiCorp PacifiCorp's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs as of December 31 (dollars in millions): Par Value 2017 2016 First mortgage bonds: 2.95% to 8.53%, due through 2022 $ 1,875 $ 1,872 $ 1,872 2.95% to 8.23%, due 2023 to 2026 1,224 1,218 1,217 7.70% due 2031 300 298 298 5.25% to 6.25%, due 2034 to 2037 2,050 2,040 2,039 4.10% to 6.35%, due 2038 to 2042 1,250 1,236 1,235 Variable-rate series, tax-exempt bond obligations (2017-1.60% to 1.87%; 2016-0.69% to 0.86%): Due 2018 to 2020 79 79 91 Due 2018 to 2025 (1) 70 70 108 Due 2024 (1)(2) 143 142 142 Due 2024 to 2025 (2) 50 50 50 Capital lease obligations - 8.75% to 14.61%, due through 2035 20 20 27 Total PacifiCorp $ 7,061 $ 7,025 $ 7,079 (1) Supported by $216 million and $255 million of fully available letters of credit issued under committed bank arrangements as of December 31, 2017 and 2016 , respectively. (2) Secured by pledged first mortgage bonds registered to and held by the tax-exempt bond trustee generally with the same interest rates, maturity dates and redemption provisions as the tax-exempt bond obligations. The issuance of PacifiCorp's first mortgage bonds is limited by available property, earnings tests and other provisions of PacifiCorp's mortgage. Approximately $27 billion of PacifiCorp's eligible property (based on original cost) was subject to the lien of the mortgage as of December 31, 2017 . MidAmerican Funding MidAmerican Funding's long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 MidAmerican Funding: 6.927% Senior Bonds, due 2029 $ 239 $ 216 $ 291 MidAmerican Energy: Tax-exempt bond obligations - Variable-rate tax-exempt bond obligation series: (2017-1.91%, 2016-0.76%), due 2023-2047 370 368 219 First Mortgage Bonds: 2.40%, due 2019 500 499 499 3.70%, due 2023 250 248 248 3.50%, due 2024 500 501 501 3.10%, due 2027 375 372 — 4.80%, due 2043 350 346 345 4.40%, due 2044 400 394 394 4.25%, due 2046 450 445 445 3.95%, due 2047 475 470 — Notes: 5.95% Series, due 2017 — — 250 5.30% Series, due 2018 350 350 350 6.75% Series, due 2031 400 396 396 5.75% Series, due 2035 300 298 298 5.80% Series, due 2036 350 348 347 Transmission upgrade obligation, 4.45% and 3.42% due through 2035 and 2036, respectively 8 6 7 Capital lease obligations - 4.16%, due through 2020 2 2 2 Total MidAmerican Energy 5,080 5,043 4,301 Total MidAmerican Funding $ 5,319 $ 5,259 $ 4,592 In February 2018, MidAmerican Energy issued $700 million of its 3.65% First Mortgage Bonds due August 2048. In December 2017, MidAmerican Funding completed a cash tender offer for a portion of its 6.927% Senior Bonds. The total pre-tax costs of the tender offer of $29 million were recorded in other, net on the Consolidated Statement of Operations. Pursuant to MidAmerican Energy's mortgage dated September 9, 2013, MidAmerican Energy's first mortgage bonds, currently and from time to time outstanding, are secured by a first mortgage lien on substantially all of its electric generating, transmission and distribution property within the state of Iowa, subject to certain exceptions and permitted encumbrances. As of December 31, 2017 , MidAmerican Energy's eligible property subject to the lien of the mortgage totaled approximately $16 billion based on original cost. Additionally, MidAmerican Energy's senior notes outstanding are equally and ratably secured with the first mortgage bonds as required by the indentures under which the senior notes were issued. MidAmerican Energy's variable-rate tax-exempt obligations bear interest at rates that are periodically established through remarketing of the bonds in the short-term tax-exempt market. MidAmerican Energy, at its option, may change the mode of interest calculation for these bonds by selecting from among several floating or fixed rate alternatives. The interest rates shown in the table above are the weighted average interest rates as of December 31, 2017 and 2016 . MidAmerican Energy maintains revolving credit facility agreements to provide liquidity for holders of these issues and $180 million of the variable rate, tax-exempt bonds are secured by an equal amount of first mortgage bonds pursuant to MidAmerican Energy's mortgage dated September 9, 2013, as supplemented and amended. NV Energy NV Energy's long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 NV Energy - 6.250% Senior Notes, due 2020 $ 315 $ 337 $ 363 Nevada Power: General and refunding mortgage securities: 6.500% Series O, due 2018 324 324 324 6.500% Series S, due 2018 499 499 498 7.125% Series V, due 2019 500 499 499 6.650% Series N, due 2036 367 359 357 6.750% Series R, due 2037 349 348 345 5.375% Series X, due 2040 250 248 247 5.450% Series Y, due 2041 250 244 236 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.800% Pollution Control Bonds Series 2017A, due 2032 (1) 40 40 — 1.600% Pollution Control Bonds Series 2017, due 2036 (1) 40 39 — 1.600% Pollution Control Bonds Series 2017B, due 2039 (1) 13 13 — Variable-rate series - 1.890% to 1.928% Pollution Control Bonds Series 2006A, due 2032 — — 38 Pollution Control Bonds Series 2006, due 2036 — — 37 Capital and financial lease obligations - 2.750% to 11.600%, due through 2054 475 475 485 Total Nevada Power 3,107 3,088 3,066 Sierra Pacific: General and refunding mortgage securities: 3.375% Series T, due 2023 250 249 248 2.600% Series U, due 2026 400 396 395 6.750% Series P, due 2037 252 256 255 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.250% Pollution Control Series 2016A, due 2029 (2) 20 20 20 1.500% Gas Facilities Series 2016A, due 2031 (2) 59 58 58 3.000% Gas and Water Series 2016B, due 2036 (3) 60 63 64 Variable-rate series (2017 - 1.690% to 1.840%, 2016 - 0.788% to 0.800%): Water Facilities Series 2016C, due 2036 30 30 29 Water Facilities Series 2016D, due 2036 25 25 25 Water Facilities Series 2016E, due 2036 25 25 25 Capital and financial lease obligations (2017 - 2.700% to 10.396%, 2016 - 2.700% to 10.130%), due through 2054 34 34 34 Total Sierra Pacific 1,155 1,156 1,153 Total NV Energy $ 4,577 $ 4,581 $ 4,582 (1) Subject to mandatory purchase by Nevada Power in May 2020 at which date the interest rate may be adjusted from time to time. (2) Subject to mandatory purchase by Sierra Pacific in June 2019 at which date the interest rate may be adjusted from time to time. (3) Subject to mandatory purchase by Sierra Pacific in June 2022 at which date the interest rate may be adjusted from time to time. The issuance of General and Refunding Mortgage Securities by the Nevada Utilities are subject to PUCN approval and are limited by available property and other provisions of the mortgage indentures for each of Nevada Power and Sierra Pacific. As of December 31, 2017 , approximately $8.4 billion of Nevada Power's and $3.9 billion of Sierra Pacific's (based on original cost) property was subject to the liens of the mortgages. Northern Powergrid Northern Powergrid and its subsidiaries' long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value (1) 2017 2016 8.875% Bonds, due 2020 $ 135 $ 144 $ 136 9.25% Bonds, due 2020 270 279 259 3.901% to 4.586% European Investment Bank loans, due 2018 to 2022 366 366 333 7.25% Bonds, due 2022 270 279 257 2.50% Bonds due 2025 203 200 182 2.073% European Investment Bank loan, due 2025 68 69 62 2.564% European Investment Bank loans, due 2027 338 336 308 7.25% Bonds, due 2028 250 256 234 4.375% Bonds, due 2032 203 199 182 5.125% Bonds, due 2035 270 267 243 5.125% Bonds, due 2035 203 200 183 Variable-rate bond, due 2026 (2) 216 210 — Total Northern Powergrid $ 2,792 $ 2,805 $ 2,379 (1) The par values for these debt instruments are denominated in sterling. (2) Amortizes semiannually and the Company has entered into an interest rate swap that fixes the interest rate on 85% of the outstanding debt. The variable interest rate as of December 31, 2017 was 2.27% while the fixed interest rate was 2.82% . BHE Pipeline Group BHE Pipeline Group 's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 Northern Natural Gas: 5.75% Senior Notes, due 2018 $ 200 $ 200 $ 199 4.25% Senior Notes, due 2021 200 199 199 5.8% Senior Bonds, due 2037 150 149 149 4.1% Senior Bonds, due 2042 250 248 248 Total Northern Natural Gas 800 796 795 Kern River: 4.893% Senior Notes, due 2018 — — 195 Total BHE Pipeline Group $ 800 $ 796 $ 990 In April 2017, Kern River redeemed the remaining amount of its 4.893% Senior Notes due April 2018 at a redemption price determined in accordance with the terms of the indenture. The total pre-tax costs of the early redemption of $5 million were recorded in other, net on the Consolidated Statement of Operations. BHE Transmission BHE Transmission 's long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value (1) 2017 2016 AltaLink Investments, L.P.: Series 12-1 Senior Bonds, 3.674%, due 2019 $ 159 $ 162 $ 153 Series 13-1 Senior Bonds, 3.265%, due 2020 159 161 152 Series 15-1 Senior Bonds, 2.244%, due 2022 159 158 148 Total AltaLink Investments, L.P. 477 481 453 AltaLink, L.P.: Series 2008-1 Notes, 5.243%, due 2018 159 159 148 Series 2013-2 Notes, 3.621%, due 2020 100 99 93 Series 2012-2 Notes, 2.978%, due 2022 219 218 204 Series 2013-4 Notes, 3.668%, due 2023 398 397 371 Series 2014-1 Notes, 3.399%, due 2024 278 278 260 Series 2016-1 Notes, 2.747%, due 2026 278 277 259 Series 2006-1 Notes, 5.249%, due 2036 119 119 111 Series 2010-1 Notes, 5.381%, due 2040 100 99 93 Series 2010-2 Notes, 4.872%, due 2040 119 119 111 Series 2011-1 Notes, 4.462%, due 2041 219 218 204 Series 2012-1 Notes, 3.990%, due 2042 418 412 385 Series 2013-3 Notes, 4.922%, due 2043 278 278 260 Series 2014-3 Notes, 4.054%, due 2044 235 233 218 Series 2015-1 Notes, 4.090%, due 2045 278 277 259 Series 2016-2 Notes, 3.717%, due 2046 358 356 333 Series 2013-1 Notes, 4.446%, due 2053 199 198 186 Series 2014-2 Notes, 4.274%, due 2064 103 103 97 Total AltaLink, L.P. 3,858 3,840 3,592 Other: Construction Loan, 5.660%, due 2020 13 13 13 Total BHE Transmission $ 4,348 $ 4,334 $ 4,058 (1) The par values for these debt instruments are denominated in Canadian dollars. BHE Renewables BHE Renewables ' long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 Fixed-rate (1) : CE Generation Bonds, 7.416%, due 2018 $ — $ — $ 67 Salton Sea Funding Corporation Bonds, 7.475%, due 2018 — — 31 Cordova Funding Corporation Bonds, 8.48% to 9.07%, due 2019 — — 97 Bishop Hill Holdings Senior Notes, 5.125%, due 2032 94 93 99 Solar Star Funding Senior Notes, 3.950%, due 2035 314 310 311 Solar Star Funding Senior Notes, 5.375%, due 2035 975 965 966 Grande Prairie Wind Senior Notes, 3.860%, due 2037 408 404 414 Topaz Solar Farms Senior Notes, 5.750%, due 2039 755 745 780 Topaz Solar Farms Senior Notes, 4.875%, due 2039 219 217 229 Alamo 6 Senior Notes, 4.170%, due 2042 232 229 — Other 19 19 22 Variable-rate (1) : Pinyon Pines I and II Term Loans, due 2019 (2) 334 333 355 Wailuku Special Purpose Revenue Bonds, 0.90%, due 2021 — — 7 TX Jumbo Road Term Loan, due 2025 (2) 198 193 206 Marshall Wind Term Loan, due 2026 (2) 88 86 90 Total BHE Renewables $ 3,636 $ 3,594 $ 3,674 (1) Amortizes quarterly or semiannually. (2) The term loans have variable interest rates based on LIBOR plus a margin that varies during the terms of the agreements. The Company has entered into interest rate swaps that fix the interest rate on 75% of the Pinyon Pines outstanding debt and 100% of the TX Jumbo Road and Marshall Wind outstanding debt. The variable interest rate as of December 31, 2017 and 2016 was 3.32% and 2.62% , respectively, while the fixed interest rates as of December 31, 2017 and 2016 ranged from 3.21% to 3.63% . In December 2017, Wailuku River Hydroelectric Limited Partnership redeemed the remaining amount of its variable rate Special Purpose Revenue Bonds due December 2021 at a redemption price determined in accordance with the terms of the indenture. In July 2017, Cordova Funding Corporation redeemed the remaining amount of its 8.48% to 9.07% Series A Senior Secured Bonds due December 2019, CE Generation, LLC redeemed the remaining amount of its 7.416% Senior Secured Bonds due December 2018, and Salton Sea Funding Corporation redeemed the remaining amount of its 7.475% Senior Secured Series F Bonds due November 2018, each at redemption prices determined in accordance with the terms of the respective indentures. The total pre-tax costs of the early redemptions of $15 million were recorded in other, net on the Consolidated Statement of Operations. HomeServices HomeServices ' long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 Variable-rate (1) : Variable-rate term loan, 2017 - 2.819%, due 2022 $ 247 $ 247 $ — (1) Amortizes quarterly. Annual Repayments of Long-Term Debt The annual repayments of BHE and subsidiary debt for the years beginning January 1, 2018 and thereafter, excluding fair value adjustments and unamortized premiums, discounts and debt issuance costs, are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total BHE senior notes $ 1,000 $ — $ 350 $ — $ — $ 5,146 $ 6,496 BHE junior subordinated debentures — — — — — 100 100 PacifiCorp 588 351 39 425 606 5,052 7,061 MidAmerican Funding 350 501 2 — — 4,466 5,319 NV Energy 844 520 336 27 28 2,822 4,577 Northern Powergrid 66 78 483 26 501 1,638 2,792 BHE Pipeline Group 200 — — 200 — 400 800 BHE Transmission 160 160 269 — 378 3,381 4,348 BHE Renewables 209 473 168 175 172 2,439 3,636 HomeServices 14 20 27 33 153 — 247 Totals $ 3,431 $ 2,103 $ 1,674 $ 886 $ 1,838 $ 25,444 $ 35,376
PacifiCorp [Member]
Debt Instrument [Line Items]
Debt and Capital Leases Disclosures [Text Block]	Long-term Debt and Capital Lease Obligations PacifiCorp's long-term debt and capital lease obligations were as follows as of December 31 (dollars in millions): 2017 2016 Average Average Principal Carrying Interest Carrying Interest Amount Value Rate Value Rate First mortgage bonds: 2.95% to 8.53%, due 2018 to 2022 $ 1,875 $ 1,872 4.80 % $ 1,872 4.80 % 2.95% to 8.23%, due 2023 to 2026 1,224 1,218 4.10 1,217 4.10 7.70% due 2031 300 298 7.70 298 7.70 5.25% to 6.25%, due 2034 to 2037 2,050 2,040 5.90 2,039 5.90 4.10% to 6.35%, due 2038 to 2042 1,250 1,236 5.60 1,235 5.60 Variable-rate series, tax-exempt bond obligations (2017-1.60% to 1.87%; 2016-0.69% to 0.86%): Due 2018 to 2020 79 79 1.77 91 0.85 Due 2018 to 2025 (1) 70 70 1.81 108 0.74 Due 2024 (1)(2) 143 142 1.73 142 0.70 Due 2024 to 2025 (2) 50 50 1.72 50 0.80 Total long-term debt 7,041 7,005 7,052 Capital lease obligations: 8.75% to 14.61%, due through 2035 20 20 11.46 27 11.09 Total long-term debt and capital lease obligations $ 7,061 $ 7,025 $ 7,079 Reflected as: 2017 2016 Current portion of long-term debt and capital lease obligations $ 588 $ 58 Long-term debt and capital lease obligations 6,437 7,021 Total long-term debt and capital lease obligations $ 7,025 $ 7,079 1) Supported by $216 million and $255 million of fully available letters of credit issued under committed bank arrangements as of December 31, 2017 and 2016 , respectively. 2) Secured by pledged first mortgage bonds registered to and held by the tax-exempt bond trustee generally with the same interest rates, maturity dates and redemption provisions as the tax-exempt bond obligations. PacifiCorp's long-term debt generally includes provisions that allow PacifiCorp to redeem the first mortgage bonds in whole or in part at any time through the payment of a make-whole premium. Variable-rate tax-exempt bond obligations are generally redeemable at par value. PacifiCorp currently has regulatory authority from the OPUC and the IPUC to issue an additional $1.325 billion of long-term debt. PacifiCorp must make a notice filing with the Washington Utilities and Transportation Commission prior to any future issuance. PacifiCorp currently has an effective shelf registration statement filed with the United States Securities and Exchange Commission to issue up to $1.325 billion additional first mortgage bonds through January 2019. The issuance of PacifiCorp's first mortgage bonds is limited by available property, earnings tests and other provisions of PacifiCorp's mortgage. Approximately $27 billion of PacifiCorp's eligible property (based on original cost) was subject to the lien of the mortgage as of December 31, 2017 . PacifiCorp has entered into long-term agreements that qualify as capital leases and expire at various dates through March 2035 for transportation services, a power purchase agreement and real estate. The transportation services agreements included as capital leases are for the right to use pipeline facilities to provide natural gas to two of PacifiCorp's generating facilities. Net capital lease assets of $20 million and $27 million as of December 31, 2017 and 2016 , respectively, were included in property, plant and equipment, net in the Consolidated Balance Sheets. As of December 31, 2017 , the annual principal maturities of long-term debt and total capital lease obligations for 2018 and thereafter are as follows (in millions): Long-term Capital Lease Debt Obligations Total 2018 $ 586 $ 4 $ 590 2019 350 4 354 2020 38 3 41 2021 420 6 426 2022 605 2 607 Thereafter 5,042 18 5,060 Total 7,041 37 7,078 Unamortized discount and debt issuance costs (36 ) — (36 ) Amounts representing interest — (17 ) (17 ) Total $ 7,005 $ 20 $ 7,025
MidAmerican Energy Company [Member]
Debt Instrument [Line Items]
Long-term Debt [Text Block]	Long-Term Debt MidAmerican Energy's long-term debt consists of the following, including amounts maturing within one year and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 First mortgage bonds: 2.40%, due 2019 $ 500 $ 499 $ 499 3.70%, due 2023 250 248 248 3.50%, due 2024 500 501 501 3.10%, due 2027 375 372 — 4.80%, due 2043 350 346 345 4.40%, due 2044 400 394 394 4.25%, due 2046 450 445 445 3.95%, due 2047 475 470 — Notes: 5.95% Series, due 2017 — — 250 5.3% Series, due 2018 350 350 350 6.75% Series, due 2031 400 396 396 5.75% Series, due 2035 300 298 298 5.8% Series, due 2036 350 347 347 Transmission upgrade obligation, 4.45% and 3.42% due through 2035 and 2036, respectively 8 6 7 Variable-rate tax-exempt bond obligation series: (weighted average interest rate- 2017-1.91%, 2016-0.76%): Due 2023, issued in 1993 7 7 7 Due 2023, issued in 2008 57 57 57 Due 2024 35 35 35 Due 2025 13 13 13 Due 2036 33 33 33 Due 2038 45 45 45 Due 2046 30 29 29 Due 2047 150 149 — Capital lease obligations - 4.16%, due through 2020 2 2 2 Total $ 5,080 $ 5,042 $ 4,301 The annual repayments of MidAmerican Energy's long-term debt for the years beginning January 1, 2018 , and thereafter, excluding unamortized premiums, discounts and debt issuance costs, are as follows (in millions): 2018 $ 350 2019 501 2020 2 2021 — 2022 — 2023 and thereafter 4,227 In February 2018, MidAmerican Energy issued $700 million of its 3.65% First Mortgage Bonds due August 2048. Pursuant to MidAmerican Energy's mortgage dated September 9, 2013, MidAmerican Energy's first mortgage bonds, currently and from time to time outstanding, are secured by a first mortgage lien on substantially all of its electric generating, transmission and distribution property within the State of Iowa, subject to certain exceptions and permitted encumbrances. As of December 31, 2017 , MidAmerican Energy's eligible property subject to the lien of the mortgage totaled approximately $16 billion based on original cost. Additionally, MidAmerican Energy's senior notes outstanding are equally and ratably secured with the first mortgage bonds as required by the indentures under which the senior notes were issued. MidAmerican Energy's variable-rate tax-exempt bond obligations bear interest at rates that are periodically established through remarketing of the bonds in the short-term tax-exempt market. MidAmerican Energy, at its option, may change the mode of interest calculation for these bonds by selecting from among several floating or fixed rate alternatives. The interest rates shown in the table above are the weighted average interest rates as of December 31, 2017 and 2016 . MidAmerican Energy maintains revolving credit facility agreements to provide liquidity for holders of these issues. Additionally, MidAmerican Energy's obligations associated with the $30 million and $150 million variable rate, tax-exempt bond obligations due 2046 and 2047, respectively, are secured by an equal amount of first mortgage bonds pursuant to MidAmerican Energy's mortgage dated September 9, 2013, as supplemented and amended. In December 2017, the Iowa Finance Authority issued $150 million of its variable-rate, tax-exempt Solid Waste Facilities Revenue Bonds due December 2047, the proceeds of which were loaned to MidAmerican Energy and restricted for the purpose of constructing solid waste facilities. As of December 31, 2017, $108 million of the restricted proceeds are reflected in other current assets on the Balance Sheet. As of December 31, 2017 , MidAmerican Energy was in compliance with all of its applicable long-term debt covenants. In March 1999, MidAmerican Energy committed to the IUB to use commercially reasonable efforts to maintain an investment grade rating on its long-term debt and to maintain its common equity level above 42% of total capitalization unless circumstances beyond its control result in the common equity level decreasing to below 39% of total capitalization. MidAmerican Energy must seek the approval from the IUB of a reasonable utility capital structure if MidAmerican Energy's common equity level decreases below 42% of total capitalization, unless the decrease is beyond the control of MidAmerican Energy. MidAmerican Energy is also required to seek the approval of the IUB if MidAmerican Energy's equity level decreases to below 39% , even if the decrease is due to circumstances beyond the control of MidAmerican Energy. As of December 31, 2017 , MidAmerican Energy's common equity ratio was 53% computed on a basis consistent with its commitment. As a result of its regulatory commitment to maintain its common equity level above certain thresholds, MidAmerican Energy could dividend $2.1 billion as of December 31, 2017 , without falling below 42% .
MidAmerican Funding, LLC and Subsidiaries [Domain]
Debt Instrument [Line Items]
Long-term Debt [Text Block]	Long-Term Debt Refer to Note 9 of MidAmerican Energy's Notes to Financial Statements for detail and a discussion of its long-term debt. In addition to MidAmerican Energy's annual repayments of long-term debt, MidAmerican Funding has $239 million of 6.927% Senior Bonds due in 2029 , with a carrying value of $240 million and $326 million as of December 31, 2017 and 2016 , respectively. In December 2017, MidAmerican Funding redeemed through a tender offer a portion of its 6.927% Senior Bonds. A charge of $29 million for the total premium is included in other income and (expense), net on the Consolidated Statement of Operations. MidAmerican Funding parent company long-term debt is secured by a pledge of the common stock of MHC. See Item 15(c) for the Consolidated Financial Statements of MHC Inc. and subsidiaries. The bonds are the direct senior secured obligations of MidAmerican Funding and effectively rank junior to all indebtedness and other liabilities of the direct and indirect subsidiaries of MidAmerican Funding, to the extent of the assets of these subsidiaries. MidAmerican Funding may redeem the bonds in whole or in part at any time at a redemption price equal to the sum of any accrued and unpaid interest to the date of redemption and the greater of (1) 100% of the principal amount of the bonds or (2) the sum of the present values of the remaining scheduled payments of principal and interest on the bonds, discounted to the date of redemption on a semiannual basis at the treasury yield plus 25 basis points. Subsidiaries of MidAmerican Funding must make payments on their own indebtedness before making distributions to MidAmerican Funding. Refer to Note 9 of MidAmerican Energy's Notes to Financial Statements for a discussion of utility regulatory restrictions affecting distributions from MidAmerican Energy. As a result of the utility regulatory restrictions agreed to by MidAmerican Energy in March 1999, MidAmerican Funding had restricted net assets of $3.7 billion as of December 31, 2017 . As of December 31, 2017 , MidAmerican Funding was in compliance with all of its applicable long-term debt covenants. Each of MidAmerican Funding's direct or indirect subsidiaries is organized as a legal entity separate and apart from MidAmerican Funding and its other subsidiaries. It should not be assumed that any asset of any subsidiary of MidAmerican Funding will be available to satisfy the obligations of MidAmerican Funding or any of its other subsidiaries; provided, however, that unrestricted cash or other assets which are available for distribution may, subject to applicable law and the terms of financing arrangements of such parties, be advanced, loaned, paid as dividends or otherwise distributed or contributed to MidAmerican Funding, one of its subsidiaries or affiliates thereof.
Nevada Power Company [Member]
Debt Instrument [Line Items]
Debt Disclosure [Text Block]	Long-Term Debt and Financial and Capital Lease Obligations Nevada Power 's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 General and refunding mortgage securities: 6.500% Series O, due 2018 $ 324 $ 324 $ 324 6.500% Series S, due 2018 499 499 498 7.125% Series V, due 2019 500 499 499 6.650% Series N, due 2036 367 357 357 6.750% Series R, due 2037 349 346 345 5.375% Series X, due 2040 250 247 247 5.450% Series Y, due 2041 250 236 236 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.800% Pollution Control Bonds Series 2017A, due 2032 (1) 40 40 — 1.600% Pollution Control Bonds Series 2017, due 2036 (1) 40 39 — 1.600% Pollution Control Bonds Series 2017B, due 2039 (1) 13 13 — Variable-rate series - 1.890% to 1.928% Pollution Control Bonds Series 2006A, due 2032 — — 38 Pollution Control Bonds Series 2006, due 2036 — — 37 Capital and financial lease obligations - 2.750% to 11.600%, due through 2054 475 475 485 Total long-term debt and financial and capital leases $ 3,107 $ 3,075 $ 3,066 Reflected as: Current portion of long-term debt and financial and capital lease obligations $ 842 $ 17 Long-term debt and financial and capital lease obligations 2,233 3,049 Total long-term debt and financial and capital leases $ 3,075 $ 3,066 (1) Subject to mandatory purchase by Nevada Power in May 2020 at which date the interest rate may be adjusted from time to time. Annual Payment on Long-Term Debt and Financial and Capital Leases The annual repayments of long-term debt and capital and financial leases for the years beginning January 1, 2018 and thereafter, are as follows (in millions): Long-term Capital and Financial Debt Lease Obligations Total 2018 $ 823 $ 75 $ 898 2019 500 76 576 2020 — 76 76 2021 — 80 80 2022 — 75 75 Thereafter 1,309 760 2,069 Total 2,632 1,142 3,774 Unamortized premium, discount and debt issuance cost (32 ) — (32 ) Executory costs — (92 ) (92 ) Amounts representing interest — (575 ) (575 ) Total $ 2,600 $ 475 $ 3,075 The issuance of General and Refunding Mortgage Securities by Nevada Power is subject to PUCN approval and is limited by available property and other provisions of the mortgage indentures. As of December 31, 2017 , approximately $8.4 billion (based on original cost) of Nevada Power 's property was subject to the liens of the mortgages. Financial and Capital Lease Obligations • In 1984, Nevada Power entered into a 30 -year capital lease for the Pearson Building with five , five -year renewal options beginning in year 2015. In February 2010, Nevada Power amended this capital lease agreement to include the lease of the adjoining parking lot and to exercise three of the five -year renewal options beginning in year 2015. There remain two additional renewal options which could extend the lease an additional ten years. Capital assets of $24 million and $25 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 , respectively. • In 2007, Nevada Power entered into a 20 -year lease, with three 10 -year renewal options, to occupy land and building for its Beltway Complex operations center in southern Nevada. Nevada Power accounts for the building portion of the lease as a capital lease and the land portion of the lease as an operating lease. Nevada Power transferred operations to the facilities in June 2009. Capital assets of $6 million and $7 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 , respectively. • Nevada Power has long-term energy purchase contracts which qualify as capital leases. The leases were entered into between the years 1989 and 1990 and became commercially operable through 1993. The terms of the leases are for 30 years and expire between the years 2022-2023. Capital assets of $34 million and $38 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 , respectively. • Nevada Power has master leasing agreements of which various pieces of equipment qualify as capital leases. The remaining equipment is treated as operating leases. Lease terms average seven years under the master lease agreement. Capital assets of $3 million and $1 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 , respectively. • ON Line was placed in-service on December 31 , 2013. The Nevada Utilities entered into a long-term transmission use agreement, in which the Nevada Utilities have 25% interest and Great Basin Transmission South, LLC has 75% interest. Refer to Note 4 for additional information. The Nevada Utilities ' share of the long-term transmission use agreement and ownership interest is split at 95% for Nevada Power and 5% for Sierra Pacific. The term is for 41 years with the agreement ending December 31 , 2054. Payments began on January 31, 2014. ON Line assets of $396 million and $402 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 , respectively.
Sierra Pacific Power Company [Member]
Debt Instrument [Line Items]
Debt Disclosure [Text Block]	Long-Term Debt and Financial and Capital Lease Obligations Sierra Pacific 's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 General and refunding mortgage securities: 3.375% Series T, due 2023 $ 250 $ 248 $ 248 2.600% Series U, due 2026 400 396 395 6.750% Series P, due 2037 252 255 255 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.250% Pollution Control Series 2016A, due 2029 (1) 20 20 20 1.500% Gas Facilities Series 2016A, due 2031 (1) 59 58 58 3.000% Gas and Water Series 2016B, due 2036 (2) 60 63 64 Variable-rate series (2017 - 1.690% to 1.840%, 2016 - 0.788% to 0.800%): Water Facilities Series 2016C, due 2036 30 30 29 Water Facilities Series 2016D, due 2036 25 25 25 Water Facilities Series 2016E, due 2036 25 25 25 Capital and financial lease obligations (2017 - 2.700% to 10.396%, 2016 - 2.700% to 10.130%), due through 2054 34 34 34 Total long-term debt and financial and capital leases $ 1,155 $ 1,154 $ 1,153 Reflected as: Current portion of long-term debt and financial and capital lease obligations $ 2 $ 1 Long-term debt and financial and capital lease obligations 1,152 1,152 Total long-term debt and financial and capital leases $ 1,154 $ 1,153 (1) Subject to mandatory purchase by Sierra Pacific in June 2019 at which date the interest rate may be adjusted from time to time. (2) Subject to mandatory purchase by Sierra Pacific in June 2022 at which date the interest rate may be adjusted from time to time. Annual Payment on Long-Term Debt and Financial and Capital Leases The annual repayments of long-term debt and capital and financial leases for the years beginning January 1, 2018 and thereafter, are as follows (in millions): Long-term Capital and Financial Debt Lease Obligations Total 2018 $ — $ 4 $ 4 2019 — 4 4 2020 — 4 4 2021 — 4 4 2022 — 3 3 Thereafter 1,121 47 1,168 Total 1,121 66 1,187 Unamortized premium, discount and debt issuance cost (1 ) — (1 ) Amounts representing interest — (32 ) (32 ) Total $ 1,120 $ 34 $ 1,154 The issuance of General and Refunding Mortgage Securities by Sierra Pacific is subject to PUCN approval and is limited by available property and other provisions of the mortgage indentures. As of December 31, 2017 , approximately $3.9 billion (based on original cost) of Sierra Pacific 's property was subject to the liens of the mortgages. Financial and Capital Lease Obligations • Sierra Pacific has master leasing agreements of which various pieces of equipment qualify as capital leases. The remaining equipment is treated as operating leases. Lease terms average seven years under the master lease agreement. Capital assets of $3 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 . • ON Line was placed in-service on December 31, 2013. The Nevada Utilities entered into a long-term transmission use agreement, in which the Nevada Utilities have 25% interest and Great Basin Transmission South, LLC has 75% interest. Refer to Note 4 for additional information. The Nevada Utilities share of the long-term transmission use agreement and ownership interest is split at 5% for Sierra Pacific and 95% for Nevada Power. The term is for 41 years with the agreement ending December 31, 2054. Payments began on January 31, 2014. ON Line assets of $21 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 . • In 2015, Sierra Pacific entered into a 20 -year capital lease for the Fort Churchill Solar Array. Capital assets of $9 million and $10 million were included in property, plant and equipment, net as of December 31 , 2017 and 2016 , respectively.

Risk Management and Hedging Act

Risk Management and Hedging Activities (Notes)	12 Months Ended
	Dec. 31, 2017
Derivative [Line Items]
Risk Management and Hedging Activities [Text Block]	Risk Management and Hedging Activities The Company is exposed to the impact of market fluctuations in commodity prices, interest rates and foreign currency exchange rates. The Company is principally exposed to electricity, natural gas, coal and fuel oil commodity price risk primarily through BHE's ownership of PacifiCorp, MidAmerican Energy, Nevada Power and Sierra Pacific (collectively, the "Utilities") as they have an obligation to serve retail customer load in their regulated service territories. The Company also provides nonregulated retail electricity and natural gas services in competitive markets. The Utilities' load and generating facilities represent substantial underlying commodity positions. Exposures to commodity prices consist mainly of variations in the price of fuel required to generate electricity, wholesale electricity that is purchased and sold and natural gas supply for retail customers. Commodity prices are subject to wide price swings as supply and demand are impacted by, among many other unpredictable items, weather, market liquidity, generating facility availability, customer usage, storage and transmission and transportation constraints. Interest rate risk exists on variable-rate short- and long-term debt, future debt issuances and mortgage commitments. Additionally, the Company is exposed to foreign currency exchange rate risk from its business operations and investments in Great Britain and Canada. The Company does not engage in a material amount of proprietary trading activities. Each of the Company's business platforms has established a risk management process that is designed to identify, assess, manage, mitigate, monitor and report each of the various types of risk involved in its business. To mitigate a portion of its commodity price risk, the Company uses commodity derivative contracts, which may include forwards, futures, options, swaps and other agreements, to effectively secure future supply or sell future production generally at fixed prices. The Company manages its interest rate risk by limiting its exposure to variable interest rates primarily through the issuance of fixed-rate long-term debt and by monitoring market changes in interest rates. Additionally, the Company may from time to time enter into interest rate derivative contracts, such as interest rate swaps or locks, forward sale commitments or mortgage interest rate lock commitments, to mitigate the Company's exposure to interest rate risk. The Company does not hedge all of its commodity price, interest rate and foreign currency exchange rate risks, thereby exposing the unhedged portion to changes in market prices. There have been no significant changes in the Company's accounting policies related to derivatives. Refer to Notes 2 , 6 and 15 for additional information on derivative contracts. The following table, which reflects master netting arrangements and excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of the Company's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Consolidated Balance Sheets (in millions): Other Other Other Current Other Current Long-term Assets Assets Liabilities Liabilities Total As of December 31, 2017: Not designated as hedging contracts: Commodity assets (1) $ 29 $ 92 $ 6 $ 4 $ 131 Commodity liabilities (1) (6 ) — (64 ) (93 ) (163 ) Interest rate assets 16 — — — 16 Interest rate liabilities — — (1 ) (7 ) (8 ) Total 39 92 (59 ) (96 ) (24 ) Designated as hedging contracts: Commodity assets 4 9 2 1 16 Commodity liabilities (3 ) (7 ) (3 ) (4 ) (17 ) Interest rate assets — 8 — — 8 Interest rate liabilities — — — — — Total 1 10 (1 ) (3 ) 7 Total derivatives 40 102 (60 ) (99 ) (17 ) Cash collateral receivable — — 18 58 76 Total derivatives - net basis $ 40 $ 102 $ (42 ) $ (41 ) $ 59 As of December 31, 2016: Not designated as hedging contracts: Commodity assets (1) $ 42 $ 86 $ 5 $ 2 $ 135 Commodity liabilities (1) (10 ) — (46 ) (150 ) (206 ) Interest rate assets 15 — — — 15 Interest rate liabilities — — (4 ) (6 ) (10 ) Total 47 86 (45 ) (154 ) (66 ) Designated as hedging contracts: Commodity assets 1 — 2 3 6 Commodity liabilities — — (14 ) (8 ) (22 ) Interest rate assets — 8 — — 8 Interest rate liabilities — — (3 ) — (3 ) Total 1 8 (15 ) (5 ) (11 ) Total derivatives 48 94 (60 ) (159 ) (77 ) Cash collateral receivable — — 13 61 74 Total derivatives - net basis $ 48 $ 94 $ (47 ) $ (98 ) $ (3 ) (1) The Company's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of December 31, 2017 and 2016 , a net regulatory asset of $119 million and $148 million , respectively, was recorded related to the net derivative liability of $32 million and $71 million , respectively. The difference between the net regulatory asset and the net derivative liability relates primarily to a power purchase agreement derivative at BHE Renewables. Not Designated as Hedging Contracts The following table reconciles the beginning and ending balances of the Company's net regulatory assets and summarizes the pre-tax gains and losses on commodity derivative contracts recognized in net regulatory assets, as well as amounts reclassified to earnings for the years ended December 31 (in millions): Commodity Derivatives 2017 2016 2015 Beginning balance $ 148 $ 250 $ 223 Changes in fair value recognized in net regulatory assets 53 (30 ) 128 Net gains (losses) reclassified to operating revenue 10 (5 ) 1 Net losses reclassified to cost of sales (92 ) (67 ) (102 ) Ending balance $ 119 $ 148 $ 250 Designated as Hedging Contracts The Company uses commodity derivative contracts accounted for as cash flow hedges to hedge electricity and natural gas commodity prices for delivery to nonregulated customers and other transactions. Certain commodity derivative contracts have settled and the fair value at the date of settlement remains in AOCI and is recognized in earnings when the forecasted transactions impact earnings. The following table reconciles the beginning and ending balances of the Company's AOCI (pre-tax) and summarizes pre-tax gains and losses on commodity derivative contracts designated and qualifying as cash flow hedges recognized in OCI, as well as amounts reclassified to earnings for the years ended December 31 (in millions): Commodity Derivatives 2017 2016 2015 Beginning balance $ 16 $ 46 $ 32 Changes in fair value recognized in OCI 15 26 52 Net gains reclassified to operating revenue 1 1 9 Net losses reclassified to cost of sales (32 ) (57 ) (47 ) Ending balance $ — $ 16 $ 46 Realized gains and losses on hedges and hedge ineffectiveness are recognized in income as operating revenue, cost of sales, operating expense or interest expense depending upon the nature of the item being hedged. For the years ended December 31, 2017 , 2016 and 2015 , hedge ineffectiveness was insignificant . As of December 31, 2017 , the Company had cash flow hedges with expiration dates extending through June 2026 . Derivative Contract Volumes The following table summarizes the net notional amounts of outstanding derivative contracts with fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Electricity purchases Megawatt hours 4 5 Natural gas purchases Decatherms 310 271 Fuel purchases Gallons — 11 Interest rate swaps US$ 679 714 Interest rate swaps £ 136 — Mortgage commitments, net US$ (422 ) (309 ) Credit Risk The Utilities are exposed to counterparty credit risk associated with wholesale energy supply and marketing activities with other utilities, energy marketing companies, financial institutions and other market participants. Credit risk may be concentrated to the extent the Utilities' counterparties have similar economic, industry or other characteristics and due to direct or indirect relationships among the counterparties. Before entering into a transaction, the Utilities analyze the financial condition of each significant wholesale counterparty, establish limits on the amount of unsecured credit to be extended to each counterparty and evaluate the appropriateness of unsecured credit limits on an ongoing basis. To further mitigate wholesale counterparty credit risk, the Utilities enter into netting and collateral arrangements that may include margining and cross-product netting agreements and obtain third-party guarantees, letters of credit and cash deposits. If required, the Utilities exercise rights under these arrangements, including calling on the counterparty's credit support arrangement. Collateral and Contingent Features In accordance with industry practice, certain wholesale derivative contracts contain credit support provisions that in part base certain collateral requirements on credit ratings for senior unsecured debt as reported by one or more of the three recognized credit rating agencies. These derivative contracts may either specifically provide bilateral rights to demand cash or other security if credit exposures on a net basis exceed specified rating-dependent threshold levels ("credit-risk-related contingent features") or provide the right for counterparties to demand "adequate assurance," or in some cases terminate the contract, in the event of a material adverse change in creditworthiness. These rights can vary by contract and by counterparty. As of December 31, 2017 , the applicable credit ratings from the three recognized credit rating agencies were investment grade. The aggregate fair value of the Company's derivative contracts in liability positions with specific credit-risk-related contingent features totaled $145 million and $190 million as of December 31, 2017 and 2016 , respectively, for which the Company had posted collateral of $74 million and $69 million , respectively, in the form of cash deposits. If all credit-risk-related contingent features for derivative contracts in liability positions had been triggered as of December 31, 2017 and 2016 , the Company would have been required to post $56 million and $110 million , respectively, of additional collateral. The Company's collateral requirements could fluctuate considerably due to market price volatility, changes in credit ratings, changes in legislation or regulation, or other factors.
PacifiCorp [Member]
Derivative [Line Items]
Risk Management and Hedging Activities [Text Block]	Risk Management and Hedging Activities PacifiCorp is exposed to the impact of market fluctuations in commodity prices and interest rates. PacifiCorp is principally exposed to electricity, natural gas, coal and fuel oil commodity price risk as it has an obligation to serve retail customer load in its service territories. PacifiCorp's load and generating facilities represent substantial underlying commodity positions. Exposures to commodity prices consist mainly of variations in the price of fuel required to generate electricity and wholesale electricity that is purchased and sold. Commodity prices are subject to wide price swings as supply and demand are impacted by, among many other unpredictable items, weather, market liquidity, generating facility availability, customer usage, storage, and transmission and transportation constraints. Interest rate risk exists on variable-rate debt and future debt issuances. PacifiCorp does not engage in a material amount of proprietary trading activities. PacifiCorp has established a risk management process that is designed to identify, assess, manage, mitigate, monitor and report, each of the various types of risk involved in its business. To mitigate a portion of its commodity price risk, PacifiCorp uses commodity derivative contracts, which may include forwards, options, swaps and other agreements, to effectively secure future supply or sell future production generally at fixed prices. PacifiCorp manages its interest rate risk by limiting its exposure to variable interest rates primarily through the issuance of fixed-rate long-term debt and by monitoring market changes in interest rates. Additionally, PacifiCorp may from time to time enter into interest rate derivative contracts, such as interest rate swaps or locks, to mitigate PacifiCorp's exposure to interest rate risk. No interest rate derivatives were in place during the periods presented. PacifiCorp does not hedge all of its commodity price and interest rate risks, thereby exposing the unhedged portion to changes in market prices. There have been no significant changes in PacifiCorp's accounting policies related to derivatives. Refer to Notes 2 and 12 for additional information on derivative contracts. The following table, which reflects master netting arrangements and excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of PacifiCorp's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Consolidated Balance Sheets (in millions): Other Other Other Current Other Current Long-term Assets Assets Liabilities Liabilities Total As of December 31, 2017: Not designated as hedging contracts (1) : Commodity assets $ 11 $ 1 $ 1 $ — $ 13 Commodity liabilities (3 ) — (32 ) (82 ) (117 ) Total 8 1 (31 ) (82 ) (104 ) Total derivatives 8 1 (31 ) (82 ) (104 ) Cash collateral receivable — — 17 57 74 Total derivatives - net basis $ 8 $ 1 $ (14 ) $ (25 ) $ (30 ) As of December 31, 2016: Not designated as hedging contracts (1) : Commodity assets $ 24 $ 2 $ 1 $ — $ 27 Commodity liabilities (6 ) — (14 ) (84 ) (104 ) Total 18 2 (13 ) (84 ) (77 ) Total derivatives 18 2 (13 ) (84 ) (77 ) Cash collateral receivable — — 10 59 69 Total derivatives - net basis $ 18 $ 2 $ (3 ) $ (25 ) $ (8 ) (1) PacifiCorp's commodity derivatives are generally included in rates and as of December 31, 2017 and 2016 , a regulatory asset of $101 million and $73 million , respectively, was recorded related to the net derivative liability of $104 million and $77 million , respectively. The following table reconciles the beginning and ending balances of PacifiCorp's regulatory assets and summarizes the pre-tax gains and losses on commodity derivative contracts recognized in regulatory assets, as well as amounts reclassified to earnings for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 73 $ 133 $ 85 Changes in fair value recognized in regulatory assets 47 (27 ) 82 Net gains reclassified to operating revenue 9 10 40 Net losses reclassified to energy costs (28 ) (43 ) (74 ) Ending balance $ 101 $ 73 $ 133 Derivative Contract Volumes The following table summarizes the net notional amounts of outstanding commodity derivative contracts with fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Electricity (sales) Megawatt hours (9 ) (3 ) Natural gas purchases Decatherms 113 84 Fuel oil purchases Gallons — 11 Credit Risk PacifiCorp is exposed to counterparty credit risk associated with wholesale energy supply and marketing activities with other utilities, energy marketing companies, financial institutions and other market participants. Credit risk may be concentrated to the extent PacifiCorp's counterparties have similar economic, industry or other characteristics and due to direct or indirect relationships among the counterparties. Before entering into a transaction, PacifiCorp analyzes the financial condition of each significant wholesale counterparty, establishes limits on the amount of unsecured credit to be extended to each counterparty and evaluates the appropriateness of unsecured credit limits on an ongoing basis. To further mitigate wholesale counterparty credit risk, PacifiCorp enters into netting and collateral arrangements that may include margining and cross-product netting agreements and obtains third-party guarantees, letters of credit and cash deposits. If required, PacifiCorp exercises rights under these arrangements, including calling on the counterparty's credit support arrangement. Collateral and Contingent Features In accordance with industry practice, certain wholesale derivative contracts contain credit support provisions that in part base certain collateral requirements on credit ratings for senior unsecured debt as reported by one or more of the three recognized credit rating agencies. These derivative contracts may either specifically provide bilateral rights to demand cash or other security if credit exposures on a net basis exceed specified rating-dependent threshold levels ("credit-risk-related contingent features") or provide the right for counterparties to demand "adequate assurance" in the event of a material adverse change in PacifiCorp's creditworthiness. These rights can vary by contract and by counterparty. As of December 31, 2017 , PacifiCorp's credit ratings from the three recognized credit rating agencies were investment grade. The aggregate fair value of PacifiCorp's derivative contracts in liability positions with specific credit-risk-related contingent features totaled $110 million and $97 million as of December 31, 2017 and 2016 , respectively, for which PacifiCorp had posted collateral of $74 million and $69 million , respectively, in the form of cash deposits. If all credit-risk-related contingent features for derivative contracts in liability positions had been triggered as of December 31, 2017 and 2016 , PacifiCorp would have been required to post $34 million and $22 million , respectively, of additional collateral. PacifiCorp's collateral requirements could fluctuate considerably due to market price volatility, changes in credit ratings, changes in legislation or regulation or other factors.
MidAmerican Energy Company [Member]
Derivative [Line Items]
Risk Management and Hedging Activities [Text Block]	Risk Management and Hedging Activities MidAmerican Energy is exposed to the impact of market fluctuations in commodity prices and interest rates. MidAmerican Energy is principally exposed to electricity, natural gas, coal and fuel oil commodity price risk as it has an obligation to serve retail customer load in its regulated service territory. Prior to January 1, 2016, MidAmerican Energy also provided nonregulated retail electricity and natural gas services in competitive markets, which created contractual obligations to provide electric and natural gas services. MidAmerican Energy's load and generating facilities represent substantial underlying commodity positions. Exposures to commodity prices consist mainly of variations in the price of fuel required to generate electricity, wholesale electricity that is purchased and sold, and natural gas supply for retail customers. Commodity prices are subject to wide price swings as supply and demand are impacted by, among many other unpredictable items, weather; market liquidity; generating facility availability; customer usage; storage; and transmission and transportation constraints. Interest rate risk exists on variable-rate debt and future debt issuances. MidAmerican Energy does not engage in a material amount of proprietary trading activities. MidAmerican Energy has established a risk management process that is designed to identify, assess, monitor, report, manage and mitigate each of the various types of risk involved in its business. To mitigate a portion of its commodity price risk, MidAmerican Energy uses commodity derivative contracts, which may include forwards, futures, options, swaps and other agreements, to effectively secure future supply or sell future production generally at fixed prices. MidAmerican Energy manages its interest rate risk by limiting its exposure to variable interest rates primarily through the issuance of fixed-rate long-term debt and by monitoring market changes in interest rates. Additionally, MidAmerican Energy may from time to time enter into interest rate derivative contracts, such as interest rate swaps or locks, to mitigate its exposure to interest rate risk. MidAmerican Energy does not hedge all of its commodity price and interest rate risks, thereby exposing the unhedged portion to changes in market prices. There have been no significant changes in MidAmerican Energy's accounting policies related to derivatives. Refer to Notes 2 and 14 for additional information on derivative contracts and to Note 3 for a discussion of discontinued operations. The following table, which reflects master netting arrangements and excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of MidAmerican Energy's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Balance Sheets (in millions): Other Other Other Current Other Current Long-term Assets Assets Liabilities Liabilities Total As of December 31, 2017: Not designated as hedging contracts (1) : Commodity assets $ 6 $ — $ 1 $ — $ 7 Commodity liabilities (1 ) — (7 ) (2 ) (10 ) Total derivatives 5 — (6 ) (2 ) (3 ) Cash collateral receivable — — — — — Total derivatives - net basis $ 5 $ — $ (6 ) $ (2 ) $ (3 ) As of December 31, 2016: Not designated as hedging contracts (1) : Commodity assets $ 8 $ 2 $ — $ — $ 10 Commodity liabilities (2 ) — (3 ) (1 ) (6 ) Total derivatives 6 2 (3 ) (1 ) 4 Cash collateral receivable — — 1 — 1 Total derivatives - net basis $ 6 $ 2 $ (2 ) $ (1 ) $ 5 (1) MidAmerican Energy's commodity derivatives not designated as hedging contracts are generally included in regulated rates. Accordingly, as of December 31, 2017 , a net regulatory asset of $3 million was recorded related to the net derivative a liability of $3 million , and as of December 31, 2016 , a net regulatory liability of $(4) million was recorded related to the net derivative asset of $4 million . Not Designated as Hedging Contracts The following table reconciles the beginning and ending balances of MidAmerican Energy's net regulatory assets (liabilities) and summarizes the pre-tax gains and losses on commodity derivative contracts recognized in net regulatory assets (liabilities), as well as amounts reclassified to earnings for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ (4 ) $ 20 $ 38 Changes in fair value recognized in net regulatory assets (liabilities) 16 3 40 Net gains (losses) reclassified to operating revenue 1 (15 ) (42 ) Net losses reclassified to cost of fuel, energy and capacity (4 ) — (1 ) Net losses reclassified to cost of gas sold (6 ) (12 ) (15 ) Ending balance $ 3 $ (4 ) $ 20 The following table summarizes the pre-tax unrealized gains (losses) included on the Statements of Operations associated with MidAmerican Energy's derivative contracts not designated as hedging contracts and not recorded as a net regulatory asset or liability for the years ended December 31 (in millions): 2017 2016 2015 Nonregulated operating revenue $ — $ — $ 15 Regulated cost of fuel, energy and capacity — — 2 Nonregulated cost of sales — — (21 ) Total $ — $ — $ (4 ) Designated as Hedging Contracts MidAmerican Energy used derivative contracts accounted for as cash flow hedges to hedge electricity and natural gas commodity prices related to its unregulated retail services business, which was transferred to a subsidiary of BHE. The following table reconciles the beginning and ending balances of MidAmerican Energy's accumulated other comprehensive loss (pre-tax) and summarizes pre-tax gains and losses on derivative contracts designated and qualifying as cash flow hedges recognized in OCI, as well as amounts reclassified to earnings, for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ — $ 45 $ 34 Transfer to affiliate — (45 ) — Changes in fair value recognized in OCI — — 58 Net losses reclassified to nonregulated cost of sales — — (47 ) Ending balance $ — $ — $ 45 Derivative Contract Volumes The following table summarizes the net notional amounts of outstanding derivative contracts with fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Natural gas purchases Decatherms 21 18 Credit Risk MidAmerican Energy is exposed to counterparty credit risk associated with wholesale energy supply and marketing activities with other utilities, energy marketing companies, financial institutions and other market participants. Additionally, MidAmerican Energy participates in the regional transmission organization ("RTO") markets and has indirect credit exposure related to other participants, although RTO credit policies are designed to limit exposure to credit losses from individual participants. Credit risk may be concentrated to the extent MidAmerican Energy's counterparties have similar economic, industry or other characteristics and due to direct or indirect relationships among the counterparties. Before entering into a transaction, MidAmerican Energy analyzes the financial condition of each significant wholesale counterparty, establishes limits on the amount of unsecured credit to be extended to each counterparty, and evaluates the appropriateness of unsecured credit limits on an ongoing basis. To further mitigate wholesale counterparty credit risk, MidAmerican Energy enters into netting and collateral arrangements that may include margining and cross-product netting agreements and obtains third-party guarantees, letters of credit and cash deposits. If required, MidAmerican Energy exercises rights under these arrangements, including calling on the counterparty's credit support arrangement. Collateral and Contingent Features In accordance with industry practice, certain wholesale derivative contracts contain credit support provisions that in part base MidAmerican Energy's collateral requirements on its credit ratings for senior unsecured debt as reported by one or more of the three recognized credit rating agencies. These derivative contracts may either specifically provide bilateral rights to demand cash or other security if credit exposures on a net basis exceed specified rating-dependent threshold levels ("credit-risk-related contingent features") or provide the right for counterparties to demand "adequate assurance," or in some cases terminate the contract, in the event of a material adverse change in MidAmerican Energy's creditworthiness. These rights can vary by contract and by counterparty. As of December 31, 2017 , MidAmerican Energy's credit ratings from the three recognized credit rating agencies were investment grade. The aggregate fair value of MidAmerican Energy's derivative contracts in liability positions with specific credit-risk-related contingent features totaled $8 million and $3 million as of December 31, 2017 and 2016 , respectively, for which MidAmerican Energy had posted collateral of $- million at each date. If all credit-risk-related contingent features for derivative contracts in liability positions had been triggered as of December 31, 2017 and 2016 , MidAmerican Energy would have been required to post $- million and $2 million , respectively, of additional collateral. MidAmerican Energy's collateral requirements could fluctuate considerably due to market price volatility, changes in credit ratings, changes in legislation or regulation, or other factors. MidAmerican Energy's exposure to contingent features declined significantly as a result of the transfer of its unregulated retail services business to a subsidiary of BHE.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Derivative [Line Items]
Risk Management and Hedging Activities [Text Block]	Risk Management and Hedging Activities Refer to Note 13 of MidAmerican Energy's Notes to Financial Statements.
Nevada Power Company [Member]
Derivative [Line Items]
Risk Management and Hedging Activities [Text Block]	Risk Management and Hedging Activities Nevada Power is exposed to the impact of market fluctuations in commodity prices and interest rates. Nevada Power is principally exposed to electricity, natural gas and coal market fluctuations primarily through Nevada Power 's obligation to serve retail customer load in its regulated service territory. Nevada Power 's load and generating facilities represent substantial underlying commodity positions. Exposures to commodity prices consist mainly of variations in the price of fuel required to generate electricity and wholesale electricity that is purchased and sold. Commodity prices are subject to wide price swings as supply and demand are impacted by, among many other unpredictable items, weather, market liquidity, generating facility availability, customer usage, storage, and transmission and transportation constraints. The actual cost of fuel and purchased power is recoverable through the deferred energy mechanism. Interest rate risk exists on variable-rate debt and future debt issuances. Nevada Power does not engage in proprietary trading activities. Nevada Power has established a risk management process that is designed to identify, assess, manage, mitigate, monitor and report each of the various types of risk involved in its business. To mitigate a portion of its commodity price risk, Nevada Power uses commodity derivative contracts, which may include forwards, futures, options, swaps and other agreements, to effectively secure future supply or sell future production generally at fixed prices. Nevada Power manages its interest rate risk by limiting its exposure to variable interest rates primarily through the issuance of fixed‑rate long-term debt and by monitoring market changes in interest rates. Additionally, Nevada Power may from time to time enter into interest rate derivative contracts, such as interest rate swaps or locks, to mitigate Nevada Power 's exposure to interest rate risk. Nevada Power does not hedge all of its commodity price and interest rate risks, thereby exposing the unhedged portion to changes in market prices. There have been no significant changes in Nevada Power 's accounting policies related to derivatives. Refer to Notes 2 and 9 for additional information on derivative contracts. The following table, which excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of Nevada Power 's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Consolidated Balance Sheets (in millions): Other Other Current Long-term Liabilities Liabilities Total As of December 31, 2017: Commodity derivative liabilities (1) $ (2 ) $ (1 ) $ (3 ) As of December 31, 2016: Commodity derivative liabilities (1) $ (7 ) $ (7 ) $ (14 ) (1) Nevada Power 's commodity derivatives not designated as hedging contracts are included in regulated rates and as of December 31 , 2017 and 2016 , a regulatory asset of $3 million and $14 million , respectively, was recorded related to the derivative liability of $3 million and $14 million , respectively. Derivative Contract Volumes The following table summarizes the net notional amounts of outstanding derivative contracts with indexed and fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Electricity sales Megawatt hours — (2 ) Natural gas purchases Decatherms 125 114 Credit Risk Nevada Power is exposed to counterparty credit risk associated with wholesale energy supply and marketing activities with other utilities, energy marketing companies, financial institutions and other market participants. Credit risk may be concentrated to the extent Nevada Power 's counterparties have similar economic, industry or other characteristics and due to direct and indirect relationships among the counterparties. Before entering into a transaction, Nevada Power analyzes the financial condition of each significant wholesale counterparty, establish limits on the amount of unsecured credit to be extended to each counterparty and evaluate the appropriateness of unsecured credit limits on an ongoing basis. To further mitigate wholesale counterparty credit risk, Nevada Power enters into netting and collateral arrangements that may include margining and cross-product netting agreements and obtain third-party guarantees, letters of credit and cash deposits. If required, Nevada Power exercises rights under these arrangements, including calling on the counterparty's credit support arrangement. Collateral and Contingent Features In accordance with industry practice, certain wholesale derivative contracts contain credit support provisions that in part base certain collateral requirements on credit ratings for unsecured debt as reported by one or more of the three recognized credit rating agencies. These derivative contracts may either specifically provide rights to demand cash or other security in the event of a credit rating downgrade ("credit-risk-related contingent features") or provide the right for counterparties to demand "adequate assurance," in the event of a material adverse change in creditworthiness. These rights can vary by contract and by counterparty. As of December 31, 2017 , credit ratings from the three recognized credit rating agencies were investment grade. The aggregate fair value of Nevada Power 's derivative contracts in liability positions with specific credit-risk-related contingent features was $1 million and $2 million as of December 31, 2017 and 2016 , respectively, which represents the amount of collateral to be posted if all credit risk related contingent features for derivative contracts in liability positions had been triggered. Nevada Power 's collateral requirements could fluctuate considerably due to market price volatility, changes in credit ratings, changes in legislation or regulation or other factors.

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)	12 Months Ended
	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements [Text Block]	Fair Value Measurements The carrying value of the Company's cash, certain cash equivalents, receivables, payables, accrued liabilities and short-term borrowings approximates fair value because of the short-term maturity of these instruments. The Company has various financial assets and liabilities that are measured at fair value on the Consolidated Financial Statements using inputs from the three levels of the fair value hierarchy. A financial asset or liability classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels are as follows: • Level 1 - Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. • Level 2 - Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 - Unobservable inputs reflect the Company's judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. The Company develops these inputs based on the best information available, including its own data. The following table presents the Company's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ 1 $ 42 $ 104 $ (29 ) $ 118 Interest rate derivatives — 15 9 — 24 Mortgage loans held for sale — 465 — — 465 Money market mutual funds (2) 685 — — — 685 Debt securities: United States government obligations 176 — — — 176 International government obligations — 5 — — 5 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Equity securities: United States companies 288 — — — 288 International companies 1,968 — — — 1,968 Investment funds 178 — — — 178 $ 3,296 $ 565 $ 113 $ (29 ) $ 3,945 Liabilities: Commodity derivatives $ (3 ) $ (167 ) $ (10 ) $ 105 $ (75 ) Interest rate derivatives — (8 ) — — (8 ) $ (3 ) $ (175 ) $ (10 ) $ 105 $ (83 ) As of December 31, 2016: Assets: Commodity derivatives $ 5 $ 49 $ 87 $ (22 ) $ 119 Interest rate derivatives — 16 7 — 23 Mortgage loans held for sale — 359 — — 359 Money market mutual funds (2) 586 — — — 586 Debt securities: United States government obligations 161 — — — 161 International government obligations — 3 — — 3 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Agency, asset and mortgage-backed obligations — 2 — — 2 Equity securities: United States companies 250 — — — 250 International companies 1,190 — — — 1,190 Investment funds 147 — — — 147 $ 2,339 $ 467 $ 94 $ (22 ) $ 2,878 Liabilities: Commodity derivatives $ (2 ) $ (199 ) $ (27 ) $ 96 $ (132 ) Interest rate derivatives (1 ) (11 ) (1 ) — (13 ) $ (3 ) $ (210 ) $ (28 ) $ 96 $ (145 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $76 million and $74 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. When available, the fair value of derivative contracts is estimated using unadjusted quoted prices for identical contracts in the market in which the Company transacts. When quoted prices for identical contracts are not available, the Company uses forward price curves. Forward price curves represent the Company's estimates of the prices at which a buyer or seller could contract today for delivery or settlement at future dates. The Company bases its forward price curves upon market price quotations, when available, or internally developed and commercial models, with internal and external fundamental data inputs. Market price quotations are obtained from independent brokers, exchanges, direct communication with market participants and actual transactions executed by the Company. Market price quotations are generally readily obtainable for the applicable term of the Company's outstanding derivative contracts; therefore, the Company's forward price curves reflect observable market quotes. Market price quotations for certain electricity and natural gas trading hubs are not as readily obtainable due to the length of the contract. Given that limited market data exists for these contracts, as well as for those contracts that are not actively traded, the Company uses forward price curves derived from internal models based on perceived pricing relationships to major trading hubs that are based on unobservable inputs. The estimated fair value of these derivative contracts is a function of underlying forward commodity prices, interest rates, currency rates, related volatility, counterparty creditworthiness and duration of contracts. Refer to Note 14 for further discussion regarding the Company's risk management and hedging activities. The Company's mortgage loans held for sale are valued based on independent quoted market prices, where available, or the prices of other mortgage whole loans with similar characteristics. As necessary, these prices are adjusted for typical securitization activities, including servicing value, portfolio composition, market conditions and liquidity. The Company's investments in money market mutual funds and debt and equity securities are stated at fair value and are primarily accounted for as available-for-sale securities. When available, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. In the absence of a quoted market price or net asset value of an identical security, the fair value is determined using pricing models or net asset values based on observable market inputs and quoted market prices of securities with similar characteristics. The following table reconciles the beginning and ending balances of the Company's assets and liabilities measured at fair value on a recurring basis using significant Level 3 inputs for the years ended December 31 (in millions): Commodity Derivatives Interest Rate Derivatives Auction Rate Securities 2017 2016 2015 2017 2016 2015 2017 2016 2015 Beginning balance $ 60 $ 47 $ 51 $ 6 $ 4 $ — $ — $ 44 $ 45 Changes included in earnings 23 8 19 147 121 87 — 5 — Changes in fair value recognized in OCI (3 ) (2 ) (7 ) — — — — 8 (1 ) Changes in fair value recognized in net regulatory assets (1 ) (11 ) (19 ) — — — — — — Purchases 1 1 1 4 — — — — — Redemptions — — — — — — — (57 ) — Settlements 14 17 2 (148 ) (119 ) (86 ) — — — Transfers from Level 2 — — — — — 3 — — — Ending balance $ 94 $ 60 $ 47 $ 9 $ 6 $ 4 $ — $ — $ 44 The Company's long-term debt is carried at cost, including fair value adjustments and unamortized premiums, discounts and debt issuance costs as applicable, on the Consolidated Financial Statements. The fair value of the Company's long-term debt is a Level 2 fair value measurement and has been estimated based upon quoted market prices, where available, or at the present value of future cash flows discounted at rates consistent with comparable maturities with similar credit risks. The carrying value of the Company's variable-rate long-term debt approximates fair value because of the frequent repricing of these instruments at market rates. The following table presents the carrying value and estimated fair value of the Company's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 35,193 $ 40,522 $ 36,116 $ 40,718
PacifiCorp [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements [Text Block]	Fair Value Measurements The carrying value of PacifiCorp's cash, certain cash equivalents, receivables, payables, accrued liabilities and short-term borrowings approximates fair value because of the short-term maturity of these instruments. PacifiCorp has various financial assets and liabilities that are measured at fair value on the Consolidated Financial Statements using inputs from the three levels of the fair value hierarchy. A financial asset or liability classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels are as follows: • Level 1 - Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that PacifiCorp has the ability to access at the measurement date. • Level 2 - Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 - Unobservable inputs reflect PacifiCorp's judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. PacifiCorp develops these inputs based on the best information available, including its own data. The following table presents PacifiCorp's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ — $ 13 $ — $ (4 ) $ 9 Money market mutual funds (2) 21 — — — 21 Investment funds 21 — — — 21 $ 42 $ 13 $ — $ (4 ) $ 51 Liabilities - Commodity derivatives $ — $ (117 ) $ — $ 78 $ (39 ) As of December 31, 2016: Assets: Commodity derivatives $ — $ 27 $ — $ (7 ) $ 20 Money market mutual funds (2) 13 — — — 13 Investment funds 17 — — — 17 $ 30 $ 27 $ — $ (7 ) $ 50 Liabilities - Commodity derivatives $ — $ (104 ) $ — $ 76 $ (28 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $74 million and $69 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents, other current assets and other assets on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. When available, the fair value of derivative contracts is estimated using unadjusted quoted prices for identical contracts in the market in which PacifiCorp transacts. When quoted prices for identical contracts are not available, PacifiCorp uses forward price curves. Forward price curves represent PacifiCorp's estimates of the prices at which a buyer or seller could contract today for delivery or settlement at future dates. PacifiCorp bases its forward price curves upon market price quotations, when available, or internally developed and commercial models, with internal and external fundamental data inputs. Market price quotations are obtained from independent energy brokers, exchanges, direct communication with market participants and actual transactions executed by PacifiCorp. Market price quotations for certain major electricity and natural gas trading hubs are generally readily obtainable for the first six years; therefore, PacifiCorp's forward price curves for those locations and periods reflect observable market quotes. Market price quotations for other electricity and natural gas trading hubs are not as readily obtainable for the first six years. Given that limited market data exists for these contracts, as well as for those contracts that are not actively traded, PacifiCorp uses forward price curves derived from internal models based on perceived pricing relationships to major trading hubs that are based on unobservable inputs. The estimated fair value of these derivative contracts is a function of underlying forward commodity prices, interest rates, currency rates, related volatility, counterparty creditworthiness and duration of contracts. Refer to Note 11 for further discussion regarding PacifiCorp's risk management and hedging activities. PacifiCorp's investments in money market mutual funds and investment funds are stated at fair value and are primarily accounted for as available-for-sale securities. When available, PacifiCorp uses a readily observable quoted market price or net asset value of an identical security in an active market to record the fair value. In the absence of a quoted market price or net asset value of an identical security, the fair value is determined using pricing models or net asset values based on observable market inputs and quoted market prices of securities with similar characteristics. PacifiCorp's long-term debt is carried at cost on the Consolidated Balance Sheets. The fair value of PacifiCorp's long-term debt is a Level 2 fair value measurement and has been estimated based upon quoted market prices, where available, or at the present value of future cash flows discounted at rates consistent with comparable maturities with similar credit risks. The carrying value of PacifiCorp's variable-rate long-term debt approximates fair value because of the frequent repricing of these instruments at market rates. The following table presents the carrying value and estimated fair value of PacifiCorp's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 7,005 $ 8,370 $ 7,052 $ 8,204
MidAmerican Energy Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements [Text Block]	Fair Value Measurements The carrying value of MidAmerican Energy's cash, certain cash equivalents, receivables, payables, accrued liabilities and short-term borrowings approximates fair value because of the short-term maturity of these instruments. MidAmerican Energy has various financial assets and liabilities that are measured at fair value on the Financial Statements using inputs from the three levels of the fair value hierarchy. A financial asset or liability classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels are as follows: • Level 1 - Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that MidAmerican Energy has the ability to access at the measurement date. • Level 2 - Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 - Unobservable inputs reflect MidAmerican Energy's judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. MidAmerican Energy develops these inputs based on the best information available, including its own data. The following table presents MidAmerican Energy's assets and liabilities recognized on the Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ — $ 3 $ 4 $ (2 ) $ 5 Money market mutual funds (2) 133 — — — 133 Debt securities: United States government obligations 176 — — — 176 International government obligations — 5 — — 5 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Equity securities: United States companies 288 — — — 288 International companies 7 — — — 7 Investment funds 15 — — — 15 $ 619 $ 46 $ 4 $ (2 ) $ 667 Liabilities - commodity derivatives $ — $ (9 ) $ (1 ) $ 2 $ (8 ) As of December 31, 2016 Assets: Commodity derivatives $ — $ 9 $ 1 $ (2 ) $ 8 Money market mutual funds (2) 1 — — — 1 Debt securities: United States government obligations 161 — — — 161 International government obligations — 3 — — 3 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Agency, asset and mortgage-backed obligations — 2 — — 2 Equity securities: United States companies 250 — — — 250 International companies 5 — — — 5 Investment funds 9 — — — 9 $ 426 $ 52 $ 1 $ (2 ) $ 477 Liabilities - commodity derivatives $ — $ (3 ) $ (3 ) $ 3 $ (3 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $- million and $1 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents and investments and restricted cash and investments on the Balance Sheets. The fair value of these money market mutual funds approximates cost. Derivative contracts are recorded on the Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. When available, the fair value of derivative contracts is estimated using unadjusted quoted prices for identical contracts in the market in which MidAmerican Energy transacts. When quoted prices for identical contracts are not available, MidAmerican Energy uses forward price curves. Forward price curves represent MidAmerican Energy's estimates of the prices at which a buyer or seller could contract today for delivery or settlement at future dates. MidAmerican Energy bases its forward price curves upon market price quotations, when available, or internally developed and commercial models, with internal and external fundamental data inputs. Market price quotations are obtained from independent energy brokers, exchanges, direct communication with market participants and actual transactions executed by MidAmerican Energy. Market price quotations are generally readily obtainable for the applicable term of MidAmerican Energy's outstanding derivative contracts; therefore, MidAmerican Energy's forward price curves reflect observable market quotes. Market price quotations for certain electricity and natural gas trading hubs are not as readily obtainable due to the length of the contract. Given that limited market data exists for these contracts, as well as for those contracts that are not actively traded, MidAmerican Energy uses forward price curves derived from internal models based on perceived pricing relationships to major trading hubs that are based on unobservable inputs. The estimated fair value of these derivative contracts is a function of underlying forward commodity prices, interest rates, related volatility, counterparty creditworthiness and duration of contracts. Refer to Note 13 for further discussion regarding MidAmerican Energy's risk management and hedging activities. MidAmerican Energy's investments in money market mutual funds and debt and equity securities are stated at fair value and are primarily accounted for as available-for-sale securities. When available, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. In the absence of a quoted market price or net asset value of an identical security, the fair value is determined using pricing models or net asset values based on observable market inputs and quoted market prices of securities with similar characteristics. The following table reconciles the beginning and ending balances of MidAmerican Energy's assets measured at fair value on a recurring basis using significant Level 3 inputs for the years ended December 31 (in millions): Commodity Derivatives Auction Rate Securities 2017 2016 2015 2017 2016 2015 Beginning balance $ (2 ) $ (6 ) $ 12 $ — $ 26 $ 26 Transfer to affiliate — (4 ) — — — — Changes included in earnings (1) — — 11 — 5 — Changes in fair value recognized in OCI — — (7 ) — 4 — Changes in fair value recognized in net regulatory assets 2 (6 ) (25 ) — — — Purchases — — 1 — — — Redemptions — — — — (35 ) — Settlements 3 14 2 — — — Ending balance $ 3 $ (2 ) $ (6 ) $ — $ — $ 26 (1) Changes included in earnings related to MidAmerican Energy's unregulated retail services business that was transferred to an affiliate of BHE. Refer to Note 3 for a discussion of discontinued operations. Net unrealized gains included in earnings for the year ended December 31, 2015 , related to commodity derivatives held at December 31, 2015 , totaled $8 million . MidAmerican Energy's long-term debt is carried at cost on the Financial Statements. The fair value of MidAmerican Energy's long-term debt is a Level 2 fair value measurement and has been estimated based upon quoted market prices, where available, or at the present value of future cash flows discounted at rates consistent with comparable maturities with similar credit risks. The carrying value of MidAmerican Energy's variable-rate long-term debt approximates fair value because of the frequent repricing of these instruments at market rates. The following table presents the carrying value and estimated fair value of MidAmerican Energy's long-term debt as of December 31 (in millions): 2017 2016 Carrying Value Fair Value Carrying Value Fair Value Long-term debt $ 5,042 $ 5,686 $ 4,301 $ 4,735
MidAmerican Funding, LLC and Subsidiaries [Domain]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements [Text Block]	Fair Value Measurements Refer to Note 14 of MidAmerican Energy's Notes to Financial Statements. MidAmerican Funding's long-term debt is carried at cost on the Consolidated Financial Statements. The fair value of MidAmerican Funding's long-term debt is a Level 2 fair value measurement and has been estimated based upon quoted market prices, where available, or at the present value of future cash flows discounted at rates consistent with comparable maturities with similar credit risks. The carrying value of MidAmerican Funding's variable-rate long-term debt approximates fair value because of the frequent repricing of these instruments at market rates. The following table presents the carrying value and estimated fair value of MidAmerican Funding's long-term debt as of December 31 (in millions): 2017 2016 Carrying Value Fair Value Carrying Value Fair Value Long-term debt $ 5,282 $ 6,006 $ 4,627 $ 5,164
Nevada Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements [Text Block]	Fair Value Measurements The carrying value of Nevada Power 's cash, certain cash equivalents, receivables, payables, accrued liabilities and short-term borrowings approximates fair value because of the short-term maturity of these instruments. Nevada Power has various financial assets and liabilities that are measured at fair value on the Consolidated Balance Sheets using inputs from the three levels of the fair value hierarchy. A financial asset or liability classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels are as follows: • Level 1 - Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that Nevada Power has the ability to access at the measurement date. • Level 2 - Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 - Unobservable inputs reflect Nevada Power 's judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. Nevada Power develops these inputs based on the best information available, including its own data. The following table presents Nevada Power 's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Total As of December 31, 2017: Assets - investment funds $ 2 $ — $ — $ 2 Liabilities - commodity derivatives $ — $ — $ (3 ) $ (3 ) As of December 31, 2016: Assets: Money market mutual funds (1) $ 220 $ — $ — $ 220 Investment funds 6 — — 6 $ 226 $ — $ — $ 226 Liabilities - commodity derivatives $ — $ — $ (14 ) $ (14 ) (1) Amounts are included in cash and cash equivalents on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. When available, the fair value of derivative contracts is estimated using unadjusted quoted prices for identical contracts in the market in which Nevada Power transacts. When quoted prices for identical contracts are not available, Nevada Power uses forward price curves. Forward price curves represent Nevada Power 's estimates of the prices at which a buyer or seller could contract today for delivery or settlement at future dates. Nevada Power bases its forward price curves upon internally developed models, with internal and external fundamental data inputs. Market price quotations for certain electricity and natural gas trading hubs are not as readily obtainable due to markets that are not active. Given that limited market data exists for these contracts, Nevada Power uses forward price curves derived from internal models based on perceived pricing relationships to major trading hubs that are based on unobservable inputs. The model incorporates a mid-market pricing convention (the mid‑point price between bid and ask prices) as a practical expedient for valuing its assets and liabilities measured and reported at fair value. The determination of the fair value for derivative contracts not only includes counterparty risk, but also the impact of Nevada Power 's nonperformance risk on its liabilities, which as of December 31, 2017 , had an immaterial impact to the fair value of its derivative contracts. As such, Nevada Power considers its derivative contracts to be valued using Level 3 inputs. Refer to Note 8 for further discussion regarding Nevada Power 's risk management and hedging activities. Nevada Power 's investments in money market mutual funds and equity securities are accounted for as available-for-sale securities and are stated at fair value. When available, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. The following table reconciles the beginning and ending balances of Nevada Power 's commodity derivative liabilities measured at fair value on a recurring basis using significant Level 3 inputs for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ (14 ) $ (22 ) $ (30 ) Changes in fair value recognized in regulatory assets (3 ) (4 ) — Settlements 14 12 8 Ending balance $ (3 ) $ (14 ) $ (22 ) Nevada Power 's long-term debt is carried at cost on the Consolidated Balance Sheets. The fair value of Nevada Power 's long-term debt is a Level 2 fair value measurement and has been estimated based upon quoted market prices, where available, or at the present value of future cash flows discounted at rates consistent with comparable maturities with similar credit risks. The carrying value of Nevada Power 's variable-rate long-term debt approximates fair value because of the frequent repricing of these instruments at market rates. The following table presents the carrying value and estimated fair value of Nevada Power 's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 2,600 $ 3,088 $ 2,581 $ 3,040
Sierra Pacific Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements [Text Block]	Fair Value Measurements The carrying value of Sierra Pacific 's cash, certain cash equivalents, receivables, payables, accrued liabilities and short-term borrowings approximates fair value because of the short-term maturity of these instruments. Sierra Pacific has various financial assets and liabilities that are measured at fair value on the Consolidated Balance Sheets using inputs from the three levels of the fair value hierarchy. A financial asset or liability classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The three levels are as follows: • Level 1 - Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that Sierra Pacific has the ability to access at the measurement date. • Level 2 - Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 - Unobservable inputs reflect Sierra Pacific 's judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. Sierra Pacific develops these inputs based on the best information available, including its own data. The following table presents Sierra Pacific 's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Total As of December 31, 2017: Assets - investment funds $ — $ — $ — $ — As of December 31, 2016: Assets: Money market mutual funds (1) $ 35 $ — $ — $ 35 Investment funds 1 — — 1 $ 36 $ — $ — $ 36 (1) Amounts are included in cash and cash equivalents on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost. Sierra Pacific 's investments in money market mutual funds and equity securities are accounted for as available-for-sale securities and are stated at fair value. When available, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. Sierra Pacific 's long-term debt is carried at cost on the Consolidated Balance Sheets. The fair value of Sierra Pacific 's long-term debt is a Level 2 fair value measurement and has been estimated based upon quoted market prices, where available, or at the present value of future cash flows discounted at rates consistent with comparable maturities with similar credit risks. The carrying value of Sierra Pacific 's variable-rate long-term debt approximates fair value because of the frequent repricing of these instruments at market rates. The following table presents the carrying value and estimated fair value of Sierra Pacific 's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 1,120 $ 1,221 $ 1,119 $ 1,191

Other, Net (Notes)

Other, Net (Notes)	12 Months Ended
	Dec. 31, 2017
MidAmerican Energy Company [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, Net [Text Block]	Other Income and (Expense) - Other, Net Other, net, as shown on the Statements of Operations, includes the following other income (expense) items for the years ended December 31 (in millions): 2017 2016 2015 Corporate-owned life insurance income $ 13 $ 8 $ 4 Gain on redemption of auction rate securities — 5 — Interest income and other, net 6 1 1 Total $ 19 $ 14 $ 5
MidAmerican Funding, LLC and Subsidiaries [Domain]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, Net [Text Block]	Other Income and (Expense) - Other, Net Other, net, as shown on the Consolidated Statements of Operations, includes the following other income (expense) items for the years ended December 31 (in millions): 2017 2016 2015 Corporate-owned life insurance income $ 13 $ 8 $ 4 Gain on redemption of auction rate securities — 5 — Gains on sales of assets and other investments 1 3 13 Loss on debt tender offer (29 ) — — Interest income and other, net 6 3 2 Total $ (9 ) $ 19 $ 19 Refer to Note 9 for information regarding the debt tender offer. MidAmerican Funding recognized a $13 million pre-tax gain on the sale of an investment in a generating facility lease in 2015.

Income Taxes (Notes)

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2017
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Income Taxes [Text Block]	Income Taxes Tax Cuts and Jobs Act The 2017 Tax Reform impacts many areas of income tax law. The most material items include the reduction of the federal corporate tax rate from 35% to 21% effective January 1, 2018, the one-time repatriation tax of foreign earnings and profits and limitations on bonus depreciation for utility property. GAAP requires the effect on deferred tax assets and liabilities of a change in tax rates be recognized in the period the tax rate change was enacted. As a result of the 2017 Tax Reform, the Company reduced deferred income tax liabilities $7,115 million . As it is probable the change in deferred taxes for the Company's regulated businesses will be passed back to customers through regulatory mechanisms, the Company increased net regulatory liabilities by $5,950 million . The reduction in deferred income tax liabilities also resulted in a decrease in deferred income tax expense of $1,150 million , mostly driven by the Company's non-regulated businesses, primarily BHE Renewables, BHE's investment in BYD Company Limited and HomeServices. As a result of the 2017 Tax Reform, BHE's consolidated net income increased by $516 million primarily due to benefits from reductions in deferred income tax liabilities of $1,150 million , partially offset by an accrual for the deemed repatriation of undistributed foreign earnings and profits totaling $419 million and equity earnings charges totaling $228 million mainly for amounts to be returned to the customers of equity investments in regulated entities. In December 2017, the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") 118 to assist in the implementation process of the 2017 Tax Reform by allowing for calculations to be classified as provisional and subject to remeasurement. There are three different classifications for the accounting: (1) completed, (2) not complete but reasonably estimable or (3) not complete and amounts are not reasonably estimable. The Company has recorded the impacts of the 2017 Tax Reform and believes all the impacts to be complete with the exception of the repatriation tax on foreign earnings and interpretations of the bonus depreciation rules. The Company has determined the amounts recorded and the interpretations relating to these two items to be provisional and subject to remeasurement during the measurement period upon obtaining the necessary additional information to complete the accounting. The Company believes the estimates for the repatriation tax to be reasonable, however, additional time is required to validate the inputs to the foreign earnings and profits calculation, the basis on which the repatriation tax is determined, and additional guidance is required to determine state income tax implications. The Company also believes its interpretations for bonus depreciation to be reasonable, however, as the guidance is clarified estimates may change. The accounting is estimated to be completed by December 2018. Income tax (benefit) expense consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ (653 ) $ (743 ) $ (929 ) State (3 ) 1 29 Foreign 83 55 84 (573 ) (687 ) (816 ) Deferred: Federal (76 ) 1,164 1,310 State 100 (59 ) (53 ) Foreign 2 (7 ) 17 26 1,098 1,274 Investment tax credits (7 ) (8 ) (8 ) Total $ (554 ) $ 403 $ 450 A reconciliation of the federal statutory income tax rate to the effective income tax rate applicable to income before income tax (benefit) expense is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Income tax credits (20 ) (14 ) (11 ) State income tax, net of federal income tax benefit 3 (1 ) (1 ) Effects of tax rate change and repatriation tax (31 ) — — Income tax effect of foreign income (5 ) (6 ) (7 ) Equity income (2 ) 2 2 Other, net (2 ) (2 ) (2 ) Effective income tax rate (22 )% 14 % 16 % Effects of 2017 Tax Reform have been included in state income tax, net of federal income tax benefit, effects of tax rate change and repatriation tax and equity income. Income tax credits relate primarily to production tax credits from wind-powered generating facilities owned by MidAmerican Energy, PacifiCorp and BHE Renewables. Federal renewable electricity production tax credits are earned as energy from qualifying wind-powered generating facilities is produced and sold and are based on a per-kilowatt hour rate pursuant to the applicable federal income tax law. Wind-powered generating facilities are eligible for the credits for 10 years from the date the qualifying generating facilities are placed in-service. Income tax effect of foreign income includes, among other items, deferred income tax benefits of $16 million in 2016 and $39 million in 2015 related to the enactment of reductions in the United Kingdom corporate income tax rate. In September 2016, the corporate income tax rate was reduced from 18% to 17% effective April 1, 2020. In November 2015, the corporate income tax rate was reduced from 20% to 19% effective April 1, 2017, with a further reduction to 18% effective April 1, 2020. Berkshire Hathaway includes the Company in its United States federal income tax return. As of December 31, 2017 , the Company had current income taxes receivable from Berkshire Hathaway of $334 million . As of December 31, 2016 , the Company had current income taxes payable to Berkshire Hathaway of $27 million . The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 1,707 $ 909 Federal, state and foreign carryforwards 1,118 987 AROs 223 326 Employee benefits 45 209 Derivative contracts 2 29 Other 448 707 Total deferred income tax assets 3,543 3,167 Valuation allowances (126 ) (64 ) Total deferred income tax assets, net 3,417 3,103 Deferred income tax liabilities: Property-related items (9,950 ) (14,237 ) Investments (843 ) (962 ) Regulatory assets (651 ) (1,449 ) Other (215 ) (334 ) Total deferred income tax liabilities (11,659 ) (16,982 ) Net deferred income tax liability $ (8,242 ) $ (13,879 ) The following table provides the Company's net operating loss and tax credit carryforwards and expiration dates as of December 31, 2017 (in millions): Federal State Foreign Total Net operating loss carryforwards (1) $ 172 $ 10,813 $ 605 $ 11,590 Deferred income taxes on net operating loss carryforwards $ 37 $ 858 $ 163 $ 1,058 Expiration dates 2023-2025 2018-2037 2035-2037 Tax credits $ 31 $ 29 $ — $ 60 Expiration dates 2023- indefinite 2018- indefinite (1) The federal net operating loss carryforwards relate principally to net operating loss carryforwards of subsidiaries that are tax residents in both the United States and the United Kingdom. The federal net operating loss carryforwards were generated prior to Berkshire Hathaway Inc.'s ownership and will begin to expire in 2023. The United States Internal Revenue Service has closed its examination of the Company's income tax returns through December 31, 2009. State tax agencies have closed their examinations of, or the statute of limitations has expired for, the Company's income tax returns through December 31, 2005, for California and Utah, through December 31, 2007 for Kansas and Minnesota, through December 31, 2008 for Illinois, through December 31, 2009 for Idaho, Montana, Nebraska and Oregon and through December 31, 2013 for Iowa. The closure of examinations, or the expiration of the statute of limitations, for state filings may not preclude the state from adjusting the state net operating loss carryforward utilized in a year for which the examination is not closed. A reconciliation of the beginning and ending balances of the Company's net unrecognized tax benefits is as follows for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 128 $ 198 Additions based on tax positions related to the current year 6 7 Additions for tax positions of prior years 70 6 Reductions for tax positions of prior years (18 ) (11 ) Statute of limitations (4 ) (1 ) Settlements (1 ) (67 ) Interest and penalties — (4 ) Ending balance $ 181 $ 128 As of December 31, 2017 and 2016 , the Company had unrecognized tax benefits totaling $158 million and $104 million , respectively, that if recognized, would have an impact on the effective tax rate. The remaining unrecognized tax benefits relate to tax positions for which ultimate deductibility is highly certain but for which there is uncertainty as to the timing of such deductibility. Recognition of these tax benefits, other than applicable interest and penalties, would not affect the Company's effective income tax rate.
PacifiCorp [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Income Taxes [Text Block]	Income Taxes Tax Cuts and Jobs Act The 2017 Tax Reform impacts many areas of income tax law. The most material items include the reduction of the federal corporate tax rate from 35% to 21% effective January 1, 2018 and limitations on bonus depreciation for utility property. GAAP requires the effect on deferred tax assets and liabilities of a change in tax rates be recognized in the period the tax rate change was enacted. As a result of the 2017 Tax Reform, PacifiCorp reduced deferred income tax liabilities $2,361 million . As it is probable the change in deferred taxes will be passed back to customers through regulatory mechanisms, PacifiCorp increased net regulatory liabilities by $2,358 million . In December 2017, the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") 118 to assist in the implementation process of the 2017 Tax Reform by allowing for calculations to be classified as provisional and subject to remeasurement. There are three different classifications for the accounting: (1) completed, (2) not complete but reasonably estimable or (3) not complete and amounts are not reasonably estimable. PacifiCorp has recorded the impacts of the 2017 Tax Reform and believes all the impacts to be complete with the exception of interpretations of the bonus depreciation rules. PacifiCorp has determined the amounts recorded and the interpretations relating to this item to be provisional and subject to remeasurement during the measurement period upon obtaining the necessary additional information to complete the accounting. PacifiCorp believes its interpretations for bonus depreciation to be reasonable, however, as the guidance is clarified estimates may change. The accounting is estimated to be completed by December 2018. Income tax expense (benefit) consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ 249 $ 169 $ 130 State 41 32 26 Total 290 201 156 Deferred: Federal 59 123 148 State 15 21 29 Total 74 144 177 Investment tax credits (4 ) (5 ) (5 ) Total income tax expense $ 360 $ 340 $ 328 A reconciliation of the federal statutory income tax rate to the effective income tax rate applicable to income before income tax expense is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % State income taxes, net of federal income tax benefit 3 3 3 Federal income tax credits (5 ) (6 ) (6 ) Other (1 ) (1 ) — Effective income tax rate 32 % 31 % 32 % Income tax credits relate primarily to production tax credits earned by PacifiCorp's wind-powered generating facilities. Federal renewable electricity production tax credits are earned as energy from qualifying wind-powered generating facilities is produced and sold and are based on a per-kilowatt hour rate pursuant to the applicable federal income tax law. Wind-powered generating facilities are eligible for the credits for 10 years from the date the qualifying generating facilities are placed in-service. The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 756 $ 393 Employee benefits 84 202 Derivative contracts and unamortized contract values 48 67 State carryforwards 83 69 Asset retirement obligations 50 78 Other 50 94 1,071 903 Deferred income tax liabilities: Property, plant and equipment (3,381 ) (5,161 ) Regulatory assets (261 ) (586 ) Other (11 ) (36 ) (3,653 ) (5,783 ) Net deferred income tax liability $ (2,582 ) $ (4,880 ) The following table provides PacifiCorp's net operating loss and tax credit carryforwards and expiration dates as of December 31, 2017 (in millions): State Net operating loss carryforwards $ 1,356 Deferred income taxes on net operating loss carryforwards $ 63 Expiration dates 2018 - 2032 Tax credit carryforwards $ 20 Expiration dates 2018 - indefinite The United States Internal Revenue Service has closed its examination of PacifiCorp's income tax returns through December 31, 2009. The statute of limitations for PacifiCorp's state income tax returns have expired through December 31, 2009, with the exception of California and Utah, for which the statute of limitations have expired through March 31, 2006. The statute of limitations expiring for state filings may not preclude the state from adjusting the state net operating loss carryforward utilized in a year for which the examination is not closed. As of December 31, 2017 and 2016 , PacifiCorp had unrecognized tax benefits totaling $10 million and $12 million , respectively, related to tax positions for which ultimate deductibility is highly certain but for which there is uncertainty as to the timing of such deductibility. Recognition of these tax benefits, other than applicable interest and penalties, would not affect PacifiCorp's effective income tax rate.
MidAmerican Energy Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Income Taxes [Text Block]	Income Taxes Tax Cuts and Jobs Act The 2017 Tax Reform impacts many areas of income tax law. The most material items include the reduction of the federal corporate tax rate from 35% to 21% effective January 1, 2018 and limitations on bonus depreciation for utility property. GAAP requires the effect on deferred tax assets and liabilities of a change in tax rates be recognized in the period the tax rate change was enacted. As a result of the 2017 Tax Reform, MidAmerican Energy reduced deferred income tax liabilities $1,824 million . As it is probable the change in deferred taxes will be passed back to customers through regulatory mechanisms, MidAmerican Energy increased net regulatory liabilities by $1,845 million . In December 2017, the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") 118 to assist in the implementation process of the 2017 Tax Reform by allowing for calculations to be classified as provisional and subject to remeasurement. There are three different classifications for the accounting: (1) completed, (2) not complete but reasonably estimable or (3) not complete and amounts are not reasonably estimable. MidAmerican Energy has recorded the impacts of 2017 Tax Reform and believes all the impacts to be complete with the exception of interpretations of the bonus depreciation rules. MidAmerican Energy has determined the amounts recorded and the interpretations relating to this item to be provisional and subject to remeasurement during the measurement period upon obtaining the necessary additional information to complete the accounting. MidAmerican Energy believes its interpretations for bonus depreciation to be reasonable; however, as the guidance is clarified estimates may change. The accounting is estimated to be completed by December 2018. MidAmerican Energy's income tax benefit from continuing operations consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ (490 ) $ (479 ) $ (415 ) State (25 ) (14 ) (6 ) (515 ) (493 ) (421 ) Deferred: Federal 335 366 281 State (2 ) (4 ) (6 ) 333 362 275 Investment tax credits (1 ) (1 ) (1 ) Total $ (183 ) $ (132 ) $ (147 ) A reconciliation of the federal statutory income tax rate to MidAmerican Energy's effective income tax rate applicable to income before income tax benefit from continuing operations is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Income tax credits (68 ) (61 ) (71 ) State income tax, net of federal income tax benefit (4 ) (3 ) (2 ) Effects of ratemaking (7 ) (3 ) (12 ) 2017 Tax Reform 2 — — Other, net (1 ) — 1 Effective income tax rate (43 )% (32 )% (49 )% Income tax credits relate primarily to production tax credits earned by MidAmerican Energy's wind-powered generating facilities. Federal renewable electricity production tax credits are earned as energy from qualifying wind-powered generating facilities is produced and sold and are based on a per-kilowatt hour rate pursuant to the applicable federal income tax law. Interim recognition of production tax credits in income is based on the annualized effective tax rate applied each period, similar to all book to tax differences. Recognition of production tax credits in income during interim periods of the year may vary significantly from actual amounts earned. Wind-powered generating facilities are eligible for the credits for 10 years from the date the qualifying generating facilities are placed in service. MidAmerican Energy's net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 443 $ 333 Asset retirement obligations 160 230 Employee benefits 45 66 Other 57 74 Total deferred income tax assets 705 703 Deferred income tax liabilities: Depreciable property (2,865 ) (3,763 ) Regulatory assets (42 ) (471 ) Other (35 ) (41 ) Total deferred income tax liabilities (2,942 ) (4,275 ) Net deferred income tax liability $ (2,237 ) $ (3,572 ) As of December 31, 2017 , MidAmerican Energy has available $40 million of state tax carryforwards, principally related to $583 million of net operating losses, that expire at various intervals between 2018 and 2036 . The United States Internal Revenue Service has closed its examination of BHE's income tax returns through December 31, 2009, including components related to MidAmerican Energy. In addition, state jurisdictions have closed their examinations of MidAmerican Energy's income tax returns for Iowa through December 31, 2013, for Illinois through December 31, 2008, and for other jurisdictions through December 31, 2009. A reconciliation of the beginning and ending balances of MidAmerican Energy's net unrecognized tax benefits is as follows for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 10 $ 10 Additions based on tax positions related to the current year 1 — Additions for tax positions of prior years 23 10 Reductions based on tax positions related to the current year (4 ) (2 ) Reductions for tax positions of prior years (19 ) (8 ) Interest and penalties 1 — Ending balance $ 12 $ 10 As of December 31, 2017 , MidAmerican Energy had unrecognized tax benefits totaling $38 million that, if recognized, would have an impact on the effective tax rate. The remaining unrecognized tax benefits relate to tax positions for which ultimate deductibility is highly certain but for which there is uncertainty as to the timing of such deductibility. Recognition of these tax benefits, other than applicable interest and penalties, would not affect MidAmerican Energy's effective income tax rate.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Income Taxes [Text Block]	Income Taxes Tax Cuts and Jobs Act On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law, which impacts many areas of income tax law. The most material items include the reduction of the federal corporate tax rate from 35% to 21% effective January 1, 2018 and limitations on bonus depreciation for utility property. Accounting principles generally accepted in the United States of America ("GAAP") require the effect on deferred tax assets and liabilities of a change in tax rates be recognized in the period the tax rate change was enacted. As a result of the 2017 Tax Reform, MidAmerican Funding reduced deferred income tax liabilities $1,822 million . As it is probable the change in deferred taxes for the MidAmerican Funding's regulated businesses will be passed back to customers through regulatory mechanisms, MidAmerican Funding increased net regulatory liabilities by $1,845 million . In December 2017, the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") 118 to assist in the implementation process of the 2017 Tax Reform by allowing for calculations to be classified as provisional and subject to remeasurement. There are three different classifications for the accounting: (1) completed, (2) not complete but reasonably estimable or (3) not complete and amounts are not reasonably estimable. MidAmerican Funding has recorded the impacts of 2017 Tax Reform and believes all the impacts to be complete with the exception of interpretations of the bonus depreciation rules. MidAmerican Funding has determined the amounts recorded and the interpretations relating to this item to be provisional and subject to remeasurement during the measurement period upon obtaining the necessary additional information to complete the accounting. MidAmerican Funding believes its interpretations for bonus depreciation to be reasonable; however, as the guidance is clarified estimates may change. The accounting is estimated to be completed by December 2018. MidAmerican Funding's income tax benefit from continuing operations consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ (505 ) $ (485 ) $ (418 ) State (31 ) (16 ) (8 ) (536 ) (501 ) (426 ) Deferred: Federal 338 367 282 State (3 ) (4 ) (5 ) 335 363 277 Investment tax credits (1 ) (1 ) (1 ) Total $ (202 ) $ (139 ) $ (150 ) A reconciliation of the federal statutory income tax rate MidAmerican Funding's the effective income tax rate applicable to income before income tax benefit from continuing operations is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Income tax credits (77 ) (64 ) (72 ) State income tax, net of federal income tax benefit (6 ) (3 ) (3 ) Effects of ratemaking (8 ) (3 ) (12 ) 2017 Tax Reform 3 — — Other, net (1 ) — 1 Effective income tax rate (54 )% (35 )% (51 )% Income tax credits relate primarily to production tax credits earned by MidAmerican Energy's wind-powered generating facilities. Federal renewable electricity production tax credits are earned as energy from qualifying wind-powered generating facilities is produced and sold and are based on a per-kilowatt hour rate pursuant to the applicable federal income tax law. Interim recognition of production tax credits in income is based on the annualized effective tax rate applied each period, similar to all book to tax differences. Recognition of production tax credits in income during interim periods of the year may vary significantly from actual amounts earned. Wind-powered generating facilities are eligible for the credits for 10 years from the date the qualifying generating facilities are placed in service. MidAmerican Funding's net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 443 $ 333 Employee benefits 45 66 Asset retirement obligations 160 230 Other 62 82 Total deferred income tax assets 710 711 Deferred income tax liabilities: Depreciable property (2,868 ) (3,767 ) Regulatory assets (42 ) (471 ) Other (35 ) (41 ) Total deferred income tax liabilities (2,945 ) (4,279 ) Net deferred income tax liability $ (2,235 ) $ (3,568 ) As of December 31, 2017 , MidAmerican Funding has available $40 million of state tax carryforwards, principally related to $583 million of net operating losses, that expire at various intervals between 2018 and 2036 . The United States Internal Revenue Service has closed its examination of BHE's income tax returns through December 31, 2009, including components related to MidAmerican Funding. In addition, state jurisdictions have closed their examinations of MidAmerican Funding's income tax returns for Iowa through December 31, 2013, for Illinois through December 31, 2008, and for other jurisdictions through December 31, 2009. A reconciliation of the beginning and ending balances of MidAmerican Funding's net unrecognized tax benefits is as follows for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 10 $ 10 Additions based on tax positions related to the current year 1 — Additions for tax positions of prior years 23 10 Reductions based on tax positions related to the current year (4 ) (2 ) Reductions for tax positions of prior years (19 ) (8 ) Interest and penalties 1 — Ending balance $ 12 $ 10 As of December 31, 2017 , MidAmerican Funding had unrecognized tax benefits totaling $39 million that, if recognized, would have an impact on the effective tax rate. The remaining unrecognized tax benefits relate to tax positions for which ultimate deductibility is highly certain but for which there is uncertainty as to the timing of such deductibility. Recognition of these tax benefits, other than applicable interest and penalties, would not affect MidAmerican Funding's effective income tax rate.
Nevada Power Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Income Taxes [Text Block]	Income Taxes Tax Cuts and Jobs Act The 2017 Tax Reform impacts many areas of income tax law. The most material items include the reduction of the federal corporate tax rate from 35% to 21% effective January 1, 2018, limitations on bonus depreciation for utility property and the elimination of the deduction for production activities. GAAP requires the effect on deferred tax assets and liabilities of a change in tax rates be recognized in the period the tax rate change was enacted. As a result of the 2017 Tax Reform, Nevada Power reduced deferred income tax liabilities $787 million . As it is probable the change in deferred taxes will be passed back to customers through regulatory mechanisms, Nevada Power increased net regulatory liabilities by $792 million . In December 2017, the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") 118 to assist in the implementation process of the 2017 Tax Reform by allowing for calculations to be classified as provisional and subject to remeasurement. There are three different classifications for the accounting: (1) completed, (2) not complete but reasonably estimable or (3) not complete and amounts are not reasonably estimable. Nevada Power has recorded the impacts of the 2017 Tax Reform and believes all the impacts to be complete with the exception of the interpretation of the bonus depreciation rules. Nevada Power has determined the amounts recorded and the interpretation relating to this item to be provisional and subject to remeasurement during the measurement period upon obtaining the necessary additional information to complete the accounting. Nevada Power believes its interpretations for bonus depreciation to be reasonable, however, as the guidance is clarified estimates may change. The accounting is estimated to be completed by December 2018. Income tax expense (benefit) consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current – Federal $ 62 $ 68 $ — Deferred – Federal 95 79 163 Investment tax credits (1 ) (1 ) (1 ) Total income tax expense $ 156 $ 146 $ 162 A reconciliation of the federal statutory income tax rate to the effective income tax rate applicable to income before income tax expense is as follows for the years ended December 31 : 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Effect of ratemaking 1 — 1 Effect of tax rate change 1 — — Other 1 (1 ) — Effective income tax rate 38 % 34 % 36 % The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 201 $ 83 Capital and financial leases 100 170 Employee benefits 18 29 Customer advances 14 23 Federal net operating loss and credit carryforwards — 5 Other 6 16 Total deferred income tax assets 339 326 Valuation allowance — (5 ) Total deferred income tax assets, net 339 321 Deferred income tax liabilities: Property related items (796 ) (1,293 ) Regulatory assets (206 ) (321 ) Capital and financial leases (97 ) (165 ) Other (7 ) (16 ) Total deferred income tax liabilities (1,106 ) (1,795 ) Net deferred income tax liability $ (767 ) $ (1,474 ) The United States federal jurisdiction is the only significant income tax jurisdiction for NV Energy . In July 2012, the United States Internal Revenue Service and the Joint Committee on Taxation concluded their examination of NV Energy with respect to its United States federal income tax returns for December 31, 2005 through December 31, 2008.
Sierra Pacific Power Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Income Taxes [Text Block]	Income Taxes Tax Cuts and Jobs Act The 2017 Tax Reform impacts many areas of income tax law. The most material items include the reduction of the federal corporate tax rate from 35% to 21% effective January 1, 2018, limitations on bonus depreciation for utility property and the elimination of the deduction for production activities. GAAP requires the effect on deferred tax assets and liabilities of a change in tax rates be recognized in the period the tax rate change was enacted. As a result of the 2017 Tax Reform, Sierra Pacific reduced deferred income tax liabilities $342 million . As it is probable the change in deferred taxes will be passed back to customers through regulatory mechanisms, Sierra Pacific increased net regulatory liabilities by $341 million . In December 2017, the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") 118 to assist in the implementation process of the 2017 Tax Reform by allowing for calculations to be classified as provisional and subject to remeasurement. There are three different classifications for the accounting: (1) completed, (2) not complete but reasonably estimable or (3) not complete and amounts are not reasonably estimable. Sierra Pacific has recorded the impacts of the 2017 Tax Reform and believes all the impacts to be complete with the exception of the interpretation of the bonus depreciation rules. Sierra Pacific has determined the amounts recorded and the interpretation relating to this item to be provisional and subject to remeasurement during the measurement period upon obtaining the necessary additional information to complete the accounting. Sierra Pacific believes its interpretations for bonus depreciation to be reasonable, however, as the guidance is clarified estimates may change. The accounting is estimated to be completed by December 2018. Income tax expense (benefit) consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Deferred - Federal $ 56 $ 50 $ 48 Investment tax credits (1 ) (1 ) (1 ) Total income tax expense $ 55 $ 49 $ 47 A reconciliation of the federal statutory income rate to the effective income tax rate applicable to income before income tax expense is as follows for the years ended December 31 : 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Effects of ratemaking — 1 1 Effect of tax rate change (1 ) — — Other — 1 — Effective income tax rate 34 % 37 % 36 % The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 67 $ 16 Federal net operating loss and credit carryforwards 10 25 Employee benefit plans 10 22 Capital and financial leases 7 12 Customer Advances 7 9 Commodity derivative contract — 5 Other 6 6 Total deferred income tax assets 107 95 Deferred income tax liabilities: Property related items (349 ) (562 ) Regulatory assets (74 ) (124 ) Capital and financial leases (7 ) (12 ) Other (7 ) (14 ) Total deferred income tax liabilities (437 ) (712 ) Net deferred income tax liability $ (330 ) $ (617 ) The following table provides Sierra Pacific 's federal net operating loss and tax credit carryforwards and expiration dates as of December 31 , 2017 (in millions): Net operating loss carryforwards $ 18 Deferred income taxes on federal net operating loss carryforwards $ 4 Expiration dates 2033 Other tax credits $ 6 Expiration dates 2021 - 2032 The United States federal jurisdiction is the only significant income tax jurisdiction for NV Energy . In July 2012, the United States Internal Revenue Service and the Joint Committee on Taxation concluded their examination of NV Energy with respect to its United States federal income tax returns for December 31, 2005 through December 31, 2008.

Supplemental Cash Flow Disclosu

Supplemental Cash Flow Disclosures Supplemental Cash Flow Disclosures (Notes)	12 Months Ended
	Dec. 31, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Supplemental Cash Flow Disclosures [Text Block]	Supplemental Cash Flow Disclosures The summary of supplemental cash flow disclosures as of and for the years ending December 31 is as follows (in millions): 2017 2016 2015 Supplemental disclosure of cash flow information: Interest paid, net of amounts capitalized $ 1,715 $ 1,673 $ 1,764 Income taxes received, net (1) $ 540 $ 1,016 $ 1,666 Supplemental disclosure of non-cash investing and financing transactions: Accruals related to property, plant and equipment additions $ 653 $ 547 $ 718 Common stock exchanged for junior subordinated debentures $ 100 $ — $ — (1) Includes $636 million , $1.1 billion and $1.8 billion of income taxes received from Berkshire Hathaway in 2017 , 2016 and 2015 , respectively.
PacifiCorp [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Supplemental Cash Flow Disclosures [Text Block]	Supplemental Cash Flow Disclosures The summary of supplemental cash flow disclosures as of and for the years ended December 31 is as follows (in millions): 2017 2016 2015 Interest paid, net of amounts capitalized $ 350 $ 350 $ 342 Income taxes paid, net $ 340 $ 201 $ 40 Supplemental disclosure of non-cash investing and financing activities: Accounts payable related to property, plant and equipment additions $ 147 $ 101 $ 147 Accounts receivable related to property, plant and equipment sales $ — $ — $ 40
MidAmerican Energy Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Supplemental Cash Flow Disclosures [Text Block]	Supplemental Cash Flow Disclosures The summary of supplemental cash flow disclosures as of and for the years ending December 31 is as follows (in millions): 2017 2016 2015 Supplemental cash flow information: Interest paid, net of amounts capitalized $ 193 $ 181 $ 154 Income taxes received, net $ 465 $ 601 $ 629 Supplemental disclosure of non-cash investing transactions: Accounts payable related to utility plant additions $ 224 $ 131 $ 249 Dividend of unregulated retail services business (Note 3) $ — $ 90 $ —
MidAmerican Funding, LLC and Subsidiaries [Domain]
Condensed Cash Flow Statements, Captions [Line Items]
Supplemental Cash Flow Disclosures [Text Block]	Supplemental Cash Flow Information The summary of supplemental cash flow information as of and for the years ending December 31 is as follows (in millions): 2017 2016 2015 Supplemental cash flow information: Interest paid, net of amounts capitalized $ 218 $ 204 $ 177 Income taxes received, net $ 472 $ 609 $ 630 Supplemental disclosure of non-cash investing transactions: Accounts payable related to utility plant additions $ 224 $ 131 $ 249 Transfer of assets and liabilities to affiliate (Note 3) $ — $ 90 $ —
Nevada Power Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Supplemental Cash Flow Disclosures [Text Block]	Supplemental Cash Flow Disclosures The summary of supplemental cash flow disclosures as of and for the years ended December 31 is as follows (in millions): 2017 2016 2015 Supplemental disclosure of cash flow information - Interest paid, net of amounts capitalized $ 167 $ 173 $ 186 Income taxes paid $ 89 $ — $ — Supplemental disclosure of non-cash investing and financing transactions: Accruals related to property, plant and equipment additions $ 18 $ 19 $ 51 Capital and financial lease obligations incurred $ — $ (1 ) $ (5 )
Sierra Pacific Power Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Supplemental Cash Flow Disclosures [Text Block]	Supplemental Cash Flow Disclosures The summary of supplemental cash flow disclosures as of and for the years ended December 31 is as follows (in millions): 2017 2016 2015 Supplemental disclosure of cash flow information - Interest paid, net of amounts capitalized $ 40 $ 47 $ 54 Supplemental disclosure of non-cash investing and financing transactions: Accruals related to property, plant and equipment additions $ 10 $ 15 $ 24 Capital and financial lease obligations incurred $ 1 $ — $ 13

Related Party Transactions Rela

Related Party Transactions Related Party Transactions (Notes)	12 Months Ended
	Dec. 31, 2017
PacifiCorp [Member]
Related Party Transaction [Line Items]
Related Party Transactions Disclosure [Text Block]	PacifiCorp has an intercompany administrative services agreement with BHE and its subsidiaries. Amounts charged to PacifiCorp by BHE and its subsidiaries under this agreement totaled $11 million during the year ended December 31, 2017 , and $10 million during each of the years ended 2016 and 2015 . Payables associated with these administrative services were $2 million as of December 31, 2017 and 2016 , respectively. Amounts charged by PacifiCorp to BHE and its subsidiaries under this agreement totaled $3 million , $4 million and $7 million during the years ended December 31, 2017 , 2016 and 2015 , respectively. Receivables associated with these administrative services were $1 million as of December 31, 2017 and 2016 , respectively. PacifiCorp also engages in various transactions with several subsidiaries of BHE in the ordinary course of business. Services provided by these subsidiaries in the ordinary course of business and charged to PacifiCorp primarily relate to wholesale electricity purchases and transmission of electricity, transportation of natural gas and employee relocation services. These expenses totaled $6 million , $7 million and $8 million during the years ended December 31, 2017 , 2016 and 2015 , respectively. Payables associated with these services were $1 million as of December 31, 2017 and 2016 , respectively. Amounts charged by PacifiCorp to subsidiaries of BHE for wholesale electricity sales in the ordinary course of business totaled $1 million , $1 million and $2 million during the years ended December 31, 2017 , 2016 and 2015 , respectively. PacifiCorp has long-term transportation contracts with BNSF Railway Company ("BNSF"), an indirect wholly owned subsidiary of Berkshire Hathaway, PacifiCorp's ultimate parent company. Transportation costs under these contracts were $35 million , $37 million and $39 million during the years ended December 31, 2017 , 2016 and 2015 , respectively. As of December 31, 2017 and 2016 , PacifiCorp had $3 million and $1 million , respectively, of accounts payable to BNSF outstanding under these contracts, including indirect payables related to a jointly owned facility. PacifiCorp is party to a tax-sharing agreement and is part of the Berkshire Hathaway consolidated United States federal income tax return. Federal and state income taxes receivable from BHE were $59 million and $17 million as of December 31, 2017 and 2016 , respectively. For the years ended December 31, 2017 , 2016 and 2015 , cash paid for federal and state income taxes to BHE totaled $340 million , $201 million and $40 million , respectively. PacifiCorp transacts with its equity investees, Bridger Coal and Trapper Mining Inc. During the years ended December 31, 2017 , 2016 and 2015 , PacifiCorp charged Bridger Coal $2 million , $2 million and $19 million , respectively, primarily for the sale of mining equipment in 2015, administrative support and management services, as well as materials, provided by PacifiCorp to Bridger Coal. Receivables for these services, as well as for certain expenses paid by PacifiCorp and reimbursed by Bridger Coal, were $5 million and $5 million as of December 31, 2017 and 2016 , respectively. Services provided by equity investees to PacifiCorp primarily relate to coal purchases. During the years ended December 31, 2017 , 2016 and 2015 , coal purchases from PacifiCorp's equity investees totaled $170 million , $174 million and $181 million , respectively. Payables to PacifiCorp's equity investees were $18 million and $17 million as of December 31, 2017 and 2016 , respectively.
MidAmerican Energy Company [Member]
Related Party Transaction [Line Items]
Related Party Transactions Disclosure [Text Block]	Related Party Transactions The companies identified as affiliates of MidAmerican Energy are Berkshire Hathaway and its subsidiaries, including BHE and its subsidiaries. The basis for the following transactions is provided for in service agreements between MidAmerican Energy and the affiliates. MidAmerican Energy is reimbursed for charges incurred on behalf of its affiliates. The majority of these reimbursed expenses are for general costs, such as insurance and building rent, and for employee wages, benefits and costs related to corporate functions such as information technology, human resources, treasury, legal and accounting. The amount of such reimbursements was $53 million , $41 million and $46 million for 2017 , 2016 and 2015 , respectively. MidAmerican Energy reimbursed BHE in the amount of $9 million , $6 million and $7 million in 2017 , 2016 and 2015 , respectively, for its share of corporate expenses. MidAmerican Energy purchases natural gas transportation and storage capacity services from Northern Natural Gas Company, a wholly owned subsidiary of BHE, and coal transportation services from BNSF Railway Company, a wholly-owned subsidiary of Berkshire Hathaway, in the normal course of business at either tariffed or market prices. These purchases totaled $122 million , $135 million and $165 million in 2017 , 2016 and 2015 , respectively. MidAmerican Energy had accounts receivable from affiliates of $9 million and $5 million as of December 31, 2017 and 2016 , respectively, that are included in receivables on the Balance Sheets. MidAmerican Energy also had accounts payable to affiliates of $16 million and $13 million as of December 31, 2017 and 2016 , respectively, that are included in accounts payable on the Balance Sheets. MidAmerican Energy is party to a tax-sharing agreement and is part of the Berkshire Hathaway consolidated United States federal income tax return. For current federal and state income taxes, MidAmerican Energy had a receivable from BHE of $51 million as of December 31, 2017 , and a payable to BHE of $6 million as of December 31, 2016 . MidAmerican Energy received net cash receipts for federal and state income taxes from BHE totaling $465 million , $601 million and $629 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. MidAmerican Energy recognizes the full amount of the funded status for its pension and postretirement plans, and amounts attributable to MidAmerican Energy's affiliates that have not previously been recognized through income are recognized as an intercompany balance with such affiliates. MidAmerican Energy adjusts these balances when changes to the funded status of the respective plans are recognized and does not intend to settle the balances currently. Amounts receivable from affiliates attributable to the funded status of employee benefit plans totaled $16 million and $12 million as of December 31, 2017 and 2016 , respectively, and similar amounts payable to affiliates totaled $45 million and $36 million as of December 31, 2017 and 2016 , respectively. See Note 11 for further information pertaining to pension and postretirement accounting.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Related Party Transaction [Line Items]
Related Party Transactions Disclosure [Text Block]	Related Party Transactions The companies identified as affiliates of MidAmerican Funding are Berkshire Hathaway and its subsidiaries, including BHE and its subsidiaries. The basis for the following transactions is provided for in service agreements between MidAmerican Funding and the affiliates. MidAmerican Funding is reimbursed for charges incurred on behalf of its affiliates. The majority of these reimbursed expenses are for allocated general costs, such as insurance and building rent, and for employee wages, benefits and costs for corporate functions, such as information technology, human resources, treasury, legal and accounting. The amount of such reimbursements was $46 million , $35 million and $35 million for 2017 , 2016 and 2015 , respectively. MidAmerican Funding reimbursed BHE in the amount of $9 million , $6 million and $7 million in 2017 , 2016 and 2015 , respectively, for its share of corporate expenses. MidAmerican Energy purchases natural gas transportation and storage capacity services from Northern Natural Gas Company, a wholly owned subsidiary of BHE, and coal transportation services from BNSF Railway Company, a wholly-owned subsidiary of Berkshire Hathaway, in the normal course of business at either tariffed or market prices. These purchases totaled $122 million , $135 million and $165 million in 2017 , 2016 and 2015 , respectively. MHC has a $300 million revolving credit arrangement carrying interest at the 30-day LIBOR rate plus a spread to borrow from BHE. Outstanding balances are unsecured and due on demand. The outstanding balance was $164 million at an interest rate of 1.629% as of December 31, 2017 , and $31 million at an interest rate of 0.885% as of December 31, 2016 , and is reflected as note payable to affiliate on the Consolidated Balance Sheet. BHE has a $100 million revolving credit arrangement, carrying interest at the 30-day LIBOR rate plus a spread to borrow from MHC. Outstanding balances are unsecured and due on demand. There were no borrowings outstanding throughout 2017 and 2016 . MidAmerican Funding had accounts receivable from affiliates of $9 million and $7 million as of December 31, 2017 and 2016 , respectively, that are included in receivables, net on the Consolidated Balance Sheets. MidAmerican Funding also had accounts payable to affiliates of $14 million and $12 million as of December 31, 2017 and 2016 , respectively, that are included in accounts payable on the Consolidated Balance Sheets. MidAmerican Funding is party to a tax-sharing agreement and is part of the Berkshire Hathaway consolidated United States federal income tax return. For current federal and state income taxes, MidAmerican Funding had a receivable from BHE of $64 million as of December 31, 2017 , and a payable to BHE of $7 million as of December 31, 2016 . MidAmerican Funding received net cash receipts for federal and state income taxes from BHE totaling $472 million , $609 million and $631 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. MidAmerican Funding recognizes the full amount of the funded status for its pension and postretirement plans, and amounts attributable to MidAmerican Funding's affiliates that have not previously been recognized through income are recognized as an intercompany balance with such affiliates. MidAmerican Funding adjusts these balances when changes to the funded status of the respective plans are recognized and does not intend to settle the balances currently. Amounts receivable from affiliates attributable to the funded status of employee benefit plans totaled $16 million and $12 million as of December 31, 2017 and 2016 , respectively, and similar amounts payable to affiliates totaled $45 million and $36 million as of December 31, 2017 and 2016 , respectively. See Note 11 for further information pertaining to pension and postretirement accounting. The indenture pertaining to MidAmerican Funding's long-term debt restricts MidAmerican Funding from paying a distribution on its equity securities, unless after making such distribution either its debt to total capital ratio does not exceed 0.67:1 and its interest coverage ratio is not less than 2.2:1 or its senior secured long-term debt rating is at least BBB or its equivalent. MidAmerican Funding may seek a release from this restriction upon delivery to the indenture trustee of written confirmation from the ratings agencies that without this restriction MidAmerican Funding's senior secured long-term debt would be rated at least BBB+.
Nevada Power Company [Member]
Related Party Transaction [Line Items]
Related Party Transactions Disclosure [Text Block]	Related Party Transactions Nevada Power has an intercompany administrative services agreement with BHE and its subsidiaries. Amounts charged to Nevada Power under this agreement totaled $2 million for the year ended December 31 , 2017 , 2016 and 2015 . Kern River Gas Transmission Company, an indirect subsidiary of BHE , provided natural gas transportation and other services to Nevada Power of $66 million , $68 million and $68 million for each of the years ended December 31 , 2017 , 2016 and 2015 . As of December 31 , 2017 and 2016 , Nevada Power 's Consolidated Balance Sheets included amounts due to Kern River Gas Transmission Company of $5 million . Nevada Power provided electricity and other services to PacifiCorp , an indirect subsidiary of BHE , of $3 million , $2 million and $3 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. There were no receivables associated with these services as of December 31 , 2017 and 2016 . PacifiCorp provided electricity and the sale of renewable energy credits to Nevada Power of $- million, $- million and $2 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. There were no payables associated with these transactions as of December 31 , 2017 and 2016 . Nevada Power provided electricity to Sierra Pacific of $104 million , $78 million and $69 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Receivables associated with these transactions were $10 million and $45 million as of December 31 , 2017 and 2016 , respectively. Nevada Power purchased electricity from Sierra Pacific of $21 million , $17 million and $2 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Payables associated with these transactions were $- million and $12 million as of December 31 , 2017 and 2016 , respectively. Nevada Power incurs intercompany administrative and shared facility costs with NV Energy and Sierra Pacific . These transactions are governed by an intercompany service agreement and are priced at cost. Nevada Power provided services to NV Energy of $- million , $1 million , $1 million for each of the years ending December 31 , 2017 , 2016 and 2015 , respectively. NV Energy provided services to Nevada Power of $10 million , $10 million and $12 million for the years ending December 31 , 2017 , 2016 and 2015 , respectively. Nevada Power provided services to Sierra Pacific of $27 million , $24 million and $22 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Sierra Pacific provided services to Nevada Power of $17 million , $14 million and $16 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. As of December 31 , 2017 and 2016 , Nevada Power 's Consolidated Balance Sheets included amounts due to NV Energy of $29 million and $32 million , respectively. There were no receivables due from NV Energy as of December 31 , 2017 and 2016 . As of December 31 , 2017 and 2016 , Nevada Power 's Consolidated Balance Sheets included receivables due from Sierra Pacific of $5 million and $4 million , respectively. There were no payables due to Sierra Pacific as of December 31 , 2017 and 2016 . Nevada Power is party to a tax-sharing agreement with NV Energy and NV Energy is part of the Berkshire Hathaway consolidated United States federal income tax return. Federal income taxes payable to NV Energy were $38 million and $68 million as of December 31, 2017 and 2016 , respectively. Nevada Power made cash payments of $89 million , $- million and $- million for federal income taxes for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Certain disbursements for accounts payable and payroll are made by NV Energy on behalf of Nevada Power and reimbursed automatically when settled by the bank. These amounts are recorded as accounts payable at the time of disbursement.
Sierra Pacific Power Company [Member]
Related Party Transaction [Line Items]
Related Party Transactions Disclosure [Text Block]	Related Party Transactions Sierra Pacific has an intercompany administrative services agreement with BHE and its subsidiaries. Amounts charged to Sierra Pacific under this agreement totaled $1 million for the year ended December 31 , 2017 , 2016 and 2015 . Sierra Pacific provided electricity to Nevada Power of $21 million , $17 million and $2 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Receivables associated with these transactions were $- million and $12 million as of December 31 , 2017 and 2016 . Sierra Pacific purchased electricity from Nevada Power of $104 million , $78 million and $69 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Payables associated with these transactions were $10 million and $45 million as of December 31 , 2017 and 2016 , respectively. Sierra Pacific incurs intercompany administrative and shared facility costs with NV Energy and Nevada Power . These transactions are governed by an intercompany service agreement and are priced at cost. NV Energy provided services to Sierra Pacific of $5 million , $5 million and $6 million for the years ending December 31 , 2017 , 2016 and 2015 , respectively. Sierra Pacific provided services to Nevada Power of $17 million , $14 million , and $16 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Nevada Power provided services to Sierra Pacific of $27 million , $24 million , and $22 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. As of December 31 , 2017 and 2016 , Sierra Pacific 's Consolidated Balance Sheets included amounts due to NV Energy of $17 million and $18 million , respectively. There were no receivables due from NV Energy as of December 31 , 2017 and 2016 . As of December 31 , 2017 and 2016 , Sierra Pacific 's Consolidated Balance Sheets included payables due to Nevada Power of $5 million and $4 million , respectively. There were no receivables due from Nevada Power as of December 31 , 2017 and 2016 . Sierra Pacific is party to a tax-sharing agreement with NV Energy and NV Energy is part of the Berkshire Hathaway consolidated United States federal income tax return. There were no federal income taxes payable to NV Energy as of December 31, 2017 and 2016 . No cash payments were made for federal income taxes for the years ended December 31 , 2017 , 2016 and 2015 . Certain disbursements for accounts payable and payroll are made by NV Energy on behalf of Sierra Pacific and reimbursed automatically when settled by the bank. These amounts are recorded as accounts payable at the time of disbursement.

Employee Benefit Plans (Notes)

Employee Benefit Plans (Notes)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Employee Benefit Plans [Text Block]	Employee Benefit Plans Defined Benefit Plans Domestic Operations PacifiCorp, MidAmerican Energy and NV Energy sponsor defined benefit pension plans that cover a majority of all employees of BHE and its domestic energy subsidiaries. These pension plans include noncontributory defined benefit pension plans, supplemental executive retirement plans ("SERP") and a restoration plan for certain executives of NV Energy. PacifiCorp, MidAmerican Energy and NV Energy also provide certain postretirement healthcare and life insurance benefits through various plans to eligible retirees. Net Periodic Benefit Cost For purposes of calculating the expected return on plan assets, a market-related value is used. The market-related value of plan assets is calculated by spreading the difference between expected and actual investment returns over a five-year period beginning after the first year in which they occur. Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ 24 $ 29 $ 33 $ 9 $ 9 $ 11 Interest cost 116 126 121 29 31 31 Expected return on plan assets (160 ) (160 ) (169 ) (40 ) (41 ) (45 ) Net amortization 25 46 53 (14 ) (12 ) (11 ) Net periodic benefit cost (credit) $ 5 $ 41 $ 38 $ (16 ) $ (13 ) $ (14 ) Funded Status The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, beginning of year $ 2,525 $ 2,489 $ 666 $ 662 Employer contributions 64 78 5 2 Participant contributions — — 10 10 Actual return on plan assets 390 163 106 41 Settlement (15 ) (11 ) — — Benefits paid (203 ) (194 ) (51 ) (49 ) Plan assets at fair value, end of year $ 2,761 $ 2,525 $ 736 $ 666 The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Benefit obligation, beginning of year $ 2,952 $ 2,934 $ 734 $ 740 Service cost 24 29 9 9 Interest cost 116 126 29 31 Participant contributions — — 10 10 Actuarial loss (gain) 132 67 (10 ) (7 ) Amendment — 1 — — Settlement (15 ) (11 ) — — Benefits paid (203 ) (194 ) (51 ) (49 ) Benefit obligation, end of year $ 3,006 $ 2,952 $ 721 $ 734 Accumulated benefit obligation, end of year $ 2,988 $ 2,929 The funded status of the plans and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, end of year $ 2,761 $ 2,525 $ 736 $ 666 Benefit obligation, end of year 3,006 2,952 721 734 Funded status $ (245 ) $ (427 ) $ 15 $ (68 ) Amounts recognized on the Consolidated Balance Sheets: Other assets $ 66 $ 26 $ 32 $ 19 Other current liabilities (14 ) (15 ) — — Other long-term liabilities (297 ) (438 ) (17 ) (87 ) Amounts recognized $ (245 ) $ (427 ) $ 15 $ (68 ) The SERPs and restoration plan have no plan assets; however, the Company has Rabbi trusts that hold corporate-owned life insurance and other investments to provide funding for the future cash requirements of the SERPs and restoration plan. The cash surrender value of all of the policies included in the Rabbi trusts, net of amounts borrowed against the cash surrender value, plus the fair market value of other Rabbi trust investments, was $272 million and $242 million as of December 31, 2017 and 2016 , respectively. These assets are not included in the plan assets in the above table, but are reflected in noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of plan assets, projected benefit obligation and accumulated benefit obligation for (1) pension and other postretirement benefit plans with a projected benefit obligation in excess of the fair value of plan assets and (2) pension plans with an accumulated benefit obligation in excess of the fair value of plan assets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Fair value of plan assets $ 2,016 $ 1,841 $ 126 $ 413 Projected benefit obligation $ 2,327 $ 2,294 $ 143 $ 500 Accumulated benefit obligation $ 2,316 $ 2,278 Unrecognized Amounts The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Net loss $ 649 $ 775 $ 14 $ 88 Prior service credit (3 ) (7 ) (37 ) (52 ) Regulatory deferrals (4 ) (7 ) 7 7 Total $ 642 $ 761 $ (16 ) $ 43 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2017 and 2016 is as follows (in millions): Accumulated Other Regulatory Regulatory Comprehensive Asset Liability Loss Total Pension Balance, December 31, 2015 $ 729 $ (1 ) $ 13 $ 741 Net loss (gain) arising during the year 76 (11 ) — 65 Net prior service cost arising during the year 1 — — 1 Net amortization (45 ) (1 ) — (46 ) Total 32 (12 ) — 20 Balance, December 31, 2016 761 (13 ) 13 761 Net (gain) loss arising during the year (68 ) (29 ) 3 (94 ) Net amortization (28 ) (1 ) 4 (25 ) Total (96 ) (30 ) 7 (119 ) Balance, December 31, 2017 $ 665 $ (43 ) $ 20 $ 642 Regulatory Regulatory Asset Liability Total Other Postretirement Balance, December 31, 2015 $ 49 $ (12 ) $ 37 Net gain arising during the year (5 ) (1 ) (6 ) Net amortization 11 1 12 Total 6 — 6 Balance, December 31, 2016 55 (12 ) 43 Net gain arising during the year (52 ) (21 ) (73 ) Net amortization 7 7 14 Total (45 ) (14 ) (59 ) Balance, December 31, 2017 $ 10 $ (26 ) $ (16 ) The net loss, prior service credit and regulatory deferrals that will be amortized in 2018 into net periodic benefit cost are estimated to be as follows (in millions): Net Prior Service Regulatory Loss Credit Deferrals Total Pension $ 32 $ (1 ) $ (3 ) $ 28 Other postretirement 1 (15 ) 1 (13 ) Total $ 33 $ (16 ) $ (2 ) $ 15 Plan Assumptions Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost were as follows: Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Benefit obligations as of December 31: Discount rate 3.60 % 4.06 % 4.43 % 3.57 % 4.01 % 4.33 % Rate of compensation increase 2.75 % 2.75 % 2.75 % NA NA NA Net periodic benefit cost for the years ended December 31: Discount rate 4.06 % 4.43 % 4.00 % 4.01 % 4.33 % 3.93 % Expected return on plan assets 6.55 % 6.78 % 6.88 % 6.73 % 7.03 % 7.00 % Rate of compensation increase 2.75 % 2.75 % 2.75 % NA NA NA In establishing its assumption as to the expected return on plan assets, the Company utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets. 2017 2016 Assumed healthcare cost trend rates as of December 31: Healthcare cost trend rate assumed for next year 7.10 % 7.40 % Rate that the cost trend rate gradually declines to 5.00 % 5.00 % Year that the rate reaches the rate it is assumed to remain at 2025 2025 A one percentage-point change in assumed healthcare cost trend rates would have the following effects (in millions): One Percentage-Point Increase Decrease Increase (decrease) in: Total service and interest cost for the year ended December 31, 2017 $ — $ — Other postretirement benefit obligation as of December 31, 2017 4 (4 ) Contributions and Benefit Payments Employer contributions to the pension and other postretirement benefit plans are expected to be $39 million and $3 million , respectively, during 2018 . Funding to the established pension trusts is based upon the actuarially determined costs of the plans and the requirements of the Internal Revenue Code, the Employee Retirement Income Security Act of 1974 and the Pension Protection Act of 2006, as amended. The Company considers contributing additional amounts from time to time in order to achieve certain funding levels specified under the Pension Protection Act of 2006, as amended. The Company's funding policy for its other postretirement benefit plans is to generally contribute an amount equal to the net periodic benefit cost. The expected benefit payments to participants in the Company's pension and other postretirement benefit plans for 2018 through 2022 and for the five years thereafter are summarized below (in millions): Projected Benefit Payments Other Pension Postretirement 2018 $ 226 $ 54 2019 224 55 2020 224 57 2021 222 55 2022 214 54 2023-2027 979 243 Plan Assets Investment Policy and Asset Allocations The Company's investment policy for its pension and other postretirement benefit plans is to balance risk and return through a diversified portfolio of debt securities, equity securities and other alternative investments. Maturities for debt securities are managed to targets consistent with prudent risk tolerances. The plans retain outside investment advisors to manage plan investments within the parameters outlined by each plan's Pension and Employee Benefits Plans Administrative Committee. The investment portfolio is managed in line with the investment policy with sufficient liquidity to meet near-term benefit payments. The target allocations (percentage of plan assets) for the Company's pension and other postretirement benefit plan assets are as follows as of December 31, 2017 : Other Pension Postretirement % % PacifiCorp: Debt securities (1) 33-38 33-37 Equity securities (1) 49-60 61-65 Limited partnership interests 7-12 1-3 Other 0-1 0-1 MidAmerican Energy: Debt securities (1) 20-50 25-45 Equity securities (1) 60-80 45-80 Real estate funds 2-8 — Other 0-3 0-5 NV Energy: Debt securities (1) 53-77 40 Equity securities (1) 23-47 60 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities. Fair Value Measurements The following table presents the fair value of plan assets, by major category, for the Company's defined benefit pension plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 10 $ 76 $ — $ 86 Debt securities: United States government obligations 218 — — 218 Corporate obligations — 350 — 350 Municipal obligations — 16 — 16 Agency, asset and mortgage-backed obligations — 110 — 110 Equity securities: United States companies 622 — — 622 International companies 136 — — 136 Investment funds (2) 83 20 — 103 Total assets in the fair value hierarchy $ 1,069 $ 572 $ — 1,641 Investment funds (2) measured at net asset value 1,019 Limited partnership interests (3) measured at net asset value 63 Real estate funds measured at net asset value 38 Total assets measured at fair value $ 2,761 As of December 31, 2016: Cash equivalents $ 4 $ 54 $ — $ 58 Debt securities: United States government obligations 161 — — 161 International government obligations — 2 — 2 Corporate obligations — 295 — 295 Municipal obligations — 20 — 20 Agency, asset and mortgage-backed obligations — 112 — 112 Equity securities: United States companies 583 — — 583 International companies 117 — — 117 Investment funds (2) 146 — — 146 Total assets in the fair value hierarchy $ 1,011 $ 483 $ — 1,494 Investment funds (2) measured at net asset value 920 Limited partnership interests (3) measured at net asset value 61 Real estate funds measured at net asset value 50 Total assets measured at fair value $ 2,525 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 62% and 38% , respectively, for both 2017 and 2016 . Additionally, these funds are invested in United States and international securities of approximately 68% and 32% , respectively, for 2017 and 60% and 40% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of plan assets, by major category, for the Company's defined benefit other postretirement plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 11 $ 3 $ — $ 14 Debt securities: United States government obligations 20 — — 20 Corporate obligations — 36 — 36 Municipal obligations — 46 — 46 Agency, asset and mortgage-backed obligations — 29 — 29 Equity securities: United States companies 185 — — 185 International companies 8 — — 8 Investment funds 219 1 — 220 Total assets in the fair value hierarchy $ 443 $ 115 $ — 558 Investment funds measured at net asset value 174 Limited partnership interests measured at net asset value 4 Total assets measured at fair value $ 736 As of December 31, 2016: Cash equivalents $ 18 $ 2 $ — $ 20 Debt securities: United States government obligations 19 — — 19 Corporate obligations — 29 — 29 Municipal obligations — 39 — 39 Agency, asset and mortgage-backed obligations — 25 — 25 Equity securities: United States companies 217 — — 217 International companies 5 — — 5 Investment funds (2) 152 — — 152 Total assets in the fair value hierarchy $ 411 $ 95 $ — 506 Investment funds (2) measured at net asset value 156 Limited partnership interests (3) measured at net asset value 4 Total assets measured at fair value $ 666 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 68% and 32% , respectively, for 2017 and 63% and 37% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 73% and 27% , respectively, for 2017 and 72% and 28% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. For level 1 investments, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. For level 2 investments, the fair value is determined using pricing models based on observable market inputs. Shares of mutual funds not registered under the Securities Act of 1933, private equity limited partnership interests, common and commingled trust funds and investment entities are reported at fair value based on the net asset value per unit, which is used for expedience purposes. A fund's net asset value is based on the fair value of the underlying assets held by the fund less its liabilities. Foreign Operations Certain wholly-owned subsidiaries of Northern Powergrid participate in the Northern Powergrid group of the United Kingdom industry-wide Electricity Supply Pension Scheme (the "UK Plan"), which provides pension and other related defined benefits, based on final pensionable pay, to the majority of the employees of Northern Powergrid . The UK Plan is closed to employees hired after July 23, 1997. Employees hired after that date are covered by a defined contribution plan sponsored by a wholly-owned subsidiary of Northern Powergrid . Net Periodic Benefit Cost For purposes of calculating the expected return on pension plan assets, a market-related value is used. The market-related value of plan assets is calculated by spreading the difference between expected and actual investment returns over a five-year period beginning after the first year in which they occur. Net periodic benefit cost for the UK Plan included the following components for the years ended December 31 (in millions): 2017 2016 2015 Service cost $ 23 $ 20 $ 24 Interest cost 58 72 79 Expected return on plan assets (100 ) (110 ) (116 ) Settlement 31 — — Net amortization 63 44 62 Net periodic benefit cost $ 75 $ 26 $ 49 Funded Status The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): 2017 2016 Plan assets at fair value, beginning of year $ 2,169 $ 2,276 Employer contributions 58 55 Participant contributions 1 1 Actual return on plan assets 145 349 Settlement (144 ) — Benefits paid (68 ) (115 ) Foreign currency exchange rate changes 207 (397 ) Plan assets at fair value, end of year $ 2,368 $ 2,169 The following table is a reconciliation of the benefit obligation for the years ended December 31 (in millions): 2017 2016 Benefit obligation, beginning of year $ 2,125 $ 2,142 Service cost 23 20 Interest cost 58 72 Participant contributions 1 1 Actuarial loss (gain) (4 ) 387 Settlement (131 ) — Benefits paid (68 ) (115 ) Foreign currency exchange rate changes 197 (382 ) Benefit obligation, end of year $ 2,201 $ 2,125 Accumulated benefit obligation, end of year $ 1,933 $ 1,858 The funded status of the UK Plan and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): 2017 2016 Plan assets at fair value, end of year $ 2,368 $ 2,169 Benefit obligation, end of year 2,201 2,125 Funded status $ 167 $ 44 Amounts recognized on the Consolidated Balance Sheets: Other assets $ 167 $ 44 Unrecognized Amounts The portion of the funded status of the UK Plan not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): 2017 2016 Net loss $ 510 $ 590 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost, which are included in accumulated other comprehensive loss on the Consolidated Balance Sheets, for the years ended December 31 is as follows (in millions): 2017 2016 Balance, beginning of year $ 590 $ 592 Net (gain) loss arising during the year (50 ) 148 Settlement (17 ) — Net amortization (63 ) (44 ) Foreign currency exchange rate changes 50 (106 ) Total (80 ) (2 ) Balance, end of year $ 510 $ 590 The net loss that will be amortized from accumulated other comprehensive loss in 2018 into net periodic benefit cost is estimated to be $60 million . Plan Assumptions Assumptions used to determine benefit obligations and net periodic benefit cost were as follows: 2017 2016 2015 Benefit obligations as of December 31: Discount rate 2.60 % 2.70 % 3.70 % Rate of compensation increase 3.45 % 3.00 % 2.90 % Rate of future price inflation 2.95 % 3.00 % 2.90 % Net periodic benefit cost for the years ended December 31: Discount rate 2.70 % 3.70 % 3.60 % Expected return on plan assets 5.00 % 5.60 % 5.60 % Rate of compensation increase 3.00 % 2.90 % 2.80 % Rate of future price inflation 3.00 % 2.90 % 2.80 % Contributions and Benefit Payments Employer contributions to the UK Plan are expected to be £45 million during 2018 . The expected benefit payments to participants in the UK Plan for 2018 through 2022 and for the five years thereafter excluding lump sum settlement elections, using the foreign currency exchange rate as of December 31, 2017 , are summarized below (in millions): 2018 $ 72 2019 74 2020 75 2021 77 2022 79 2023-2027 427 Plan Assets Investment Policy and Asset Allocations The investment policy for the UK Plan is to balance risk and return through a diversified portfolio of debt securities, equity securities, real estate and other asset classes. Maturities for debt securities are managed to targets consistent with prudent risk tolerances. The UK Plan retains outside investment advisors to manage plan investments within the parameters set by the trustees of the UK Plan in consultation with Northern Powergrid . The investment portfolio is managed in line with the investment policy with sufficient liquidity to meet near-term benefit payments. The return on assets assumption is based on a weighted-average of the expected historical performance for the types of assets in which the UK Plan invests. The target allocations (percentage of plan assets) for the UK Plan assets are as follows as of December 31, 2017 : % Debt securities (1) 50-55 Equity securities (1) 35-40 Real estate funds and other 5-15 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds have been allocated based on the underlying investments in debt and equity securities. Fair Value Measurements The following table presents the fair value of the UK Plan assets, by major category (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 4 $ 30 $ — $ 34 Debt securities: United Kingdom government obligations 870 — — 870 Equity securities: Investment funds (2) — 1,027 — 1,027 Real estate funds — — 230 230 Total $ 874 $ 1,057 $ 230 2,161 Investment funds (2) measured at net asset value 207 Total assets measured at fair value $ 2,368 As of December 31, 2016: Cash equivalents $ 4 $ 83 $ — $ 87 Debt securities: United Kingdom government obligations 718 — — 718 Equity securities: Investment funds (2) — 1,095 — 1,095 Real estate funds — — 105 105 Total $ 722 $ 1,178 $ 105 2,005 Investment funds (2) measured at net asset value 164 Total assets measured at fair value $ 2,169 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 21% and 79% , respectively, for 2017 and 44% and 56% , respectively, for 2016 . The fair value of the UK Plan's assets are determined similar to the plan assets of the domestic plans as previously discussed. The following table reconciles the beginning and ending balances of the UK Plan assets measured at fair value using significant Level 3 inputs for the years ended December 31 (in millions): Real Estate Funds 2017 2016 2015 Beginning balance $ 105 $ 204 $ 199 Actual return on plan assets still held at period end 6 10 18 Purchases (sales) 104 (80 ) — Foreign currency exchange rate changes 15 (29 ) (13 ) Ending balance $ 230 $ 105 $ 204 Defined Contribution Plans The Company sponsors various defined contribution plans covering substantially all employees. The Company's contributions vary depending on the plan, but matching contributions are based on each participant's level of contribution, and certain participants receive contributions based on eligible pre-tax annual compensation. Contributions cannot exceed the maximum allowable for tax purposes. The Company's contributions to these plans were $103 million , $102 million and $90 million for the years ended December 31, 2017 , 2016 and 2015 , respectively.
PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee Benefit Plans [Text Block]	Employee Benefit Plans PacifiCorp sponsors defined benefit pension and other postretirement benefit plans that cover the majority of its employees, as well as a defined contribution 401(k) employee savings plan ("401(k) Plan"). In addition, PacifiCorp contributes to a joint trustee pension plan and a subsidiary previously contributed to a multiemployer pension plan for benefits offered to certain bargaining units. Pension and Other Postretirement Benefit Plans PacifiCorp's pension plans include non-contributory defined benefit pension plans, collectively the PacifiCorp Retirement Plan ("Retirement Plan"), and the Supplemental Executive Retirement Plan ("SERP"). The Retirement Plan is closed to all non-union employees hired after January 1, 2008. All non-union Retirement Plan participants hired prior to January 1, 2008 that did not elect to receive equivalent fixed contributions to the 401(k) Plan effective January 1, 2009 earned benefits based on a cash balance formula through December 31, 2016. Effective January 1, 2017, non-union employee participants with a cash balance benefit in the Retirement Plan are no longer eligible to receive pay credits in their cash balance formula. In general for union employees, benefits under the Retirement Plan were frozen at various dates from December 31, 2007 through December 31, 2011 as they are now being provided with enhanced 401(k) Plan benefits. However, certain limited union Retirement Plan participants continue to earn benefits under the Retirement Plan based on the employee's years of service and a final average pay formula. The SERP was closed to new participants as of March 21, 2006 and froze future accruals for active participants as of December 31, 2014. PacifiCorp's other postretirement benefit plan provides healthcare and life insurance benefits to eligible retirees. Net Periodic Benefit Cost For purposes of calculating the expected return on plan assets, a market-related value is used. The market-related value of plan assets is calculated by spreading the difference between expected and actual investment returns over a five-year period beginning after the first year in which they occur. Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ — $ 4 $ 4 $ 2 $ 2 $ 3 Interest cost 49 54 53 14 15 16 Expected return on plan assets (72 ) (75 ) (77 ) (21 ) (21 ) (23 ) Net amortization 14 34 42 (6 ) (5 ) (4 ) Net periodic benefit cost (credit) $ (9 ) $ 17 $ 22 $ (11 ) $ (9 ) $ (8 ) Funded Status The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, beginning of year $ 999 $ 1,043 $ 302 $ 305 Employer contributions 54 5 1 1 Participant contributions — — 7 6 Actual return on plan assets 166 51 49 17 Benefits paid (108 ) (100 ) (27 ) (27 ) Plan assets at fair value, end of year $ 1,111 $ 999 $ 332 $ 302 The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Benefit obligation, beginning of year $ 1,276 $ 1,289 $ 358 $ 362 Service cost — 4 2 2 Interest cost 49 54 14 15 Participant contributions — — 7 6 Actuarial (gain) loss 34 29 (23 ) — Benefits paid (108 ) (100 ) (27 ) (27 ) Benefit obligation, end of year $ 1,251 $ 1,276 $ 331 $ 358 Accumulated benefit obligation, end of year $ 1,251 $ 1,276 The funded status of the plans and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, end of year $ 1,111 $ 999 $ 332 $ 302 Less - Benefit obligation, end of year 1,251 1,276 331 358 Funded status $ (140 ) $ (277 ) $ 1 $ (56 ) Amounts recognized on the Consolidated Balance Sheets: Other assets $ 5 $ — $ 1 $ — Other current liabilities (4 ) (5 ) — — Other long-term liabilities (141 ) (272 ) — (56 ) Amounts recognized $ (140 ) $ (277 ) $ 1 $ (56 ) The SERP has no plan assets; however, PacifiCorp has a Rabbi trust that holds corporate-owned life insurance and other investments to provide funding for the future cash requirements of the SERP. The cash surrender value of all of the policies included in the Rabbi trust, net of amounts borrowed against the cash surrender value, plus the fair market value of other Rabbi trust investments, was $60 million and $55 million as of December 31, 2017 and 2016 , respectively. These assets are not included in the plan assets in the above table, but are reflected in cash and cash equivalents, totaling $9 million and $- million as of December 31, 2017 and 2016 , respectively, and noncurrent other assets, totaling $51 million and 55 million as of December 31, 2017 and 2016 , respectively, on the Consolidated Balance Sheets. Unrecognized Amounts The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Net loss (gain) $ 442 $ 518 $ (12 ) $ 39 Prior service credit — — (6 ) (13 ) Regulatory deferrals (4 ) (7 ) 7 8 Total $ 438 $ 511 $ (11 ) $ 34 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2017 and 2016 is as follows (in millions): Accumulated Other Regulatory Comprehensive Asset Loss Total Pension Balance, December 31, 2015 $ 473 $ 19 $ 492 Net loss arising during the year 51 2 53 Net amortization (33 ) (1 ) (34 ) Total 18 1 19 Balance, December 31, 2016 491 20 511 Net (gain) loss arising during the year (60 ) 1 (59 ) Net amortization (13 ) (1 ) (14 ) Total (73 ) — (73 ) Balance, December 31, 2017 $ 418 $ 20 $ 438 Regulatory Asset (Liability) Other Postretirement Balance, December 31, 2015 $ 26 Net loss arising during the year 3 Net amortization 5 Total 8 Balance, December 31, 2016 34 Net gain arising during the year (51 ) Net amortization 6 Total (45 ) Balance, December 31, 2017 $ (11 ) The net loss, prior service credit and regulatory deferrals that will be amortized in 2018 into net periodic benefit cost are estimated to be as follows (in millions): Net Prior Service Regulatory Loss Credit Deferrals Total Pension $ 16 $ — $ (2 ) $ 14 Other postretirement — (6 ) 1 (5 ) Total $ 16 $ (6 ) $ (1 ) $ 9 Plan Assumptions Assumptions used to determine benefit obligations and net periodic benefit cost were as follows: Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Benefit obligations as of December 31: Discount rate 3.60 % 4.05 % 4.40 % 3.60 % 4.05 % 4.35 % Rate of compensation increase N/A N/A 2.75 N/A N/A N/A Net periodic benefit cost for the years ended December 31: Discount rate 4.05 % 4.40 % 4.00 % 4.05 % 4.35 % 3.99 % Expected return on plan assets 7.25 7.50 7.50 7.25 7.50 7.08 Rate of compensation increase N/A 2.75 2.75 N/A N/A N/A In establishing its assumption as to the expected return on plan assets, PacifiCorp utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets. As a result of a plan amendment effective on January 1, 2017, the benefit obligation for the Retirement Plan is no longer affected by future increases in compensation. As a result of a labor settlement reached with UMWA in December 2014, the benefit obligation for the other postretirement plan is no longer affected by healthcare cost trends. Contributions and Benefit Payments Employer contributions to the pension and other postretirement benefit plans are expected to be $4 million and $- million, respectively, during 2018 . Funding to PacifiCorp's Retirement Plan trust is based upon the actuarially determined costs of the plan and the requirements of the Internal Revenue Code, the Employee Retirement Income Security Act of 1974 ("ERISA") and the Pension Protection Act of 2006, as amended ("PPA"). PacifiCorp considers contributing additional amounts from time to time in order to achieve certain funding levels specified under the PPA. PacifiCorp's funding of its other postretirement benefit plan is subject to tax deductibility and subordination limits and other considerations. The expected benefit payments to participants in PacifiCorp's pension and other postretirement benefit plans for 2018 through 2022 and for the five years thereafter are summarized below (in millions): Projected Benefit Payments Pension Other Postretirement 2018 $ 108 $ 25 2019 107 25 2020 103 26 2021 99 23 2022 94 23 2023-2027 393 100 Plan Assets Investment Policy and Asset Allocations PacifiCorp's investment policy for its pension and other postretirement benefit plans is to balance risk and return through a diversified portfolio of debt securities, equity securities and other alternative investments. Maturities for debt securities are managed to targets consistent with prudent risk tolerances. The plans retain outside investment advisors to manage plan investments within the parameters outlined by the PacifiCorp Pension Committee. The investment portfolio is managed in line with the investment policy with sufficient liquidity to meet near-term benefit payments. The target allocations (percentage of plan assets) for PacifiCorp's pension and other postretirement benefit plan assets are as follows as of December 31, 2017 : Pension (1) Other Postretirement (1) % % Debt securities (2) 33 - 38 33 - 37 Equity securities (2) 49 - 60 61 - 65 Limited partnership interests 7 - 12 1 - 3 Other 0 - 1 0 - 1 (1) PacifiCorp's Retirement Plan trust includes a separate account that is used to fund benefits for the other postretirement benefit plan. In addition to this separate account, the assets for the other postretirement benefit plan are held in Voluntary Employees' Beneficiary Association ("VEBA") trusts, each of which has its own investment allocation strategies. Target allocations for the other postretirement benefit plan include the separate account of the Retirement Plan trust and the VEBA trusts. (2) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities. Fair Value Measurements The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit pension plan (in millions): Input Levels for Fair Value Measurements Level 1 (1) Level 2 (1) Level 3 (1) Total As of December 31, 2017: Cash equivalents $ — $ 43 $ — $ 43 Debt securities: United States government obligations 45 — — 45 Corporate obligations — 60 — 60 Municipal obligations — 9 — 9 Agency, asset and mortgage-backed obligations — 37 — 37 Equity securities: United States companies 416 — — 416 International companies 22 — — 22 Total assets in the fair value hierarchy $ 483 $ 149 $ — 632 Investment funds (2) measured at net asset value 416 Limited partnership interests (3) measured at net asset value 63 Investments at fair value $ 1,111 As of December 31, 2016: Cash equivalents $ — $ 10 $ — $ 10 Debt securities: United States government obligations 25 — — 25 Corporate obligations — 36 — 36 Municipal obligations — 6 — 6 Agency, asset and mortgage-backed obligations — 37 — 37 Equity securities: United States companies 389 — — 389 International companies 15 — — 15 Investment funds (2) 83 — — 83 Total assets in the fair value hierarchy $ 512 $ 89 $ — 601 Investment funds (2) measured at net asset value 337 Limited partnership interests (3) measured at net asset value 61 Investments at fair value $ 999 (1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 60% and 40% respectively, for 2017 and 54% and 46% , respectively, for 2016 , and are invested in United States and international securities of approximately 57% and 43% , respectively, for 2017 and 39% and 61% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit other postretirement plan (in millions): Input Levels for Fair Value Measurements Level 1 (1) Level 2 (1) Level 3 (1) Total As of December 31, 2017: Cash and cash equivalents $ 4 $ 3 $ — $ 7 Debt securities: United States government obligations 11 — — 11 Corporate obligations — 16 — 16 Municipal obligations — 2 — 2 Agency, asset and mortgage-backed obligations — 16 — 16 Equity securities: United States companies 98 — — 98 International companies 6 — — 6 Investment funds (2) 32 — — 32 Total assets in the fair value hierarchy $ 151 $ 37 $ — 188 Investment funds (2) measured at net asset value 140 Limited partnership interests (3) measured at net asset value 4 Investments at fair value $ 332 As of December 31, 2016: Cash and cash equivalents $ 4 $ 1 $ — $ 5 Debt securities: United States government obligations 11 — — 11 Corporate obligations — 13 — 13 Municipal obligations — 2 — 2 Agency, asset and mortgage-backed obligations — 13 — 13 Equity securities: United States companies 93 — — 93 International companies 4 — — 4 Investment funds (2) 32 — — 32 Total assets in the fair value hierarchy $ 144 $ 29 $ — 173 Investment funds (2) measured at net asset value 125 Limited partnership interests (3) measured at net asset value 4 Investments at fair value $ 302 (1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 63% and 37% , respectively, for 2017 and 62% and 38% , respectively, for 2016 , and are invested in United States and international securities of approximately 77% and 23% , respectively, for 2017 and 71% and 29% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. For level 1 investments, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. For level 2 investments, the fair value is determined using pricing models based on observable market inputs. Shares of mutual funds not registered under the Securities Act of 1933, private equity limited partnership interests, common and commingled trust funds and investment entities are reported at fair value based on the net asset value per unit, which is used for expedience purposes. A fund's net asset value is based on the fair value of the underlying assets held by the fund less its liabilities. Multiemployer and Joint Trustee Pension Plans PacifiCorp contributes to the PacifiCorp/IBEW Local 57 Retirement Trust Fund ("Local 57 Trust Fund") (plan number 001) and its subsidiary, Energy West Mining Company, previously contributed to the UMWA 1974 Pension Plan (plan number 002). Contributions to these pension plans are based on the terms of collective bargaining agreements. As a result of the Utah Mine Disposition and UMWA labor settlement, PacifiCorp's subsidiary, Energy West Mining Company, triggered involuntary withdrawal from the UMWA 1974 Pension Plan in June 2015 when the UMWA employees ceased performing work for the subsidiary. PacifiCorp recorded its estimate of the withdrawal obligation in December 2014 when withdrawal was considered probable and deferred the portion of the obligation considered probable of recovery to a regulatory asset. PacifiCorp has subsequently revised its estimate due to changes in facts and circumstances for a withdrawal occurring by July 2015. As communicated in a letter received in August 2016, the plan trustees have determined a withdrawal liability of $115 million . Energy West Mining Company began making installment payments in November 2016 and has the option to elect a lump sum payment to settle the withdrawal obligation. The ultimate amount paid by Energy West Mining Company to settle the obligation is dependent on a variety of factors, including the results of ongoing negotiations with the plan trustees. The Local 57 Trust Fund is a joint trustee plan such that the board of trustees is represented by an equal number of trustees from PacifiCorp and the union. The Local 57 Trust Fund was established pursuant to the provisions of the Taft-Hartley Act and although formed with the ability for other employers to participate in the plan, there are no other employers that participate in this plan. The risk of participating in multiemployer pension plans generally differs from single-employer plans in that assets are pooled such that contributions by one employer may be used to provide benefits to employees of other participating employers and plan assets cannot revert back to employers. If an employer ceases participation in the plan, the employer may be obligated to pay a withdrawal liability based on the participants' unfunded, vested benefits in the plan. This occurred as a result of Energy West Mining Company's withdrawal from the UMWA 1974 Pension Plan. If participating employers withdraw from a multiemployer plan, the unfunded obligations of the plan may be borne by the remaining participating employers, including any employers that withdrew during the three years prior to a mass withdrawal. The following table presents PacifiCorp's and Energy West Mining Company's participation in individually significant joint trustee and multiemployer pension plans for the years ended December 31 (dollars in millions): PPA zone status or plan funded status percentage for plan years beginning July 1, Contributions (1) Plan name Employer Identification Number 2017 2016 2015 Funding improvement plan Surcharge imposed under PPA (1) 2017 2016 2015 Year contributions to plan exceeded more than 5% of total contributions (2) UMWA 1974 Pension Plan 52-1050282 Critical and Declining Critical and Declining Critical and Declining Implemented Yes $ — $ — $ 1 None Local 57 Trust Fund 87-0640888 At least 80% At least 80% At least 80% None None $ 7 $ 8 $ 8 2015, 2014, 2013 (1) PacifiCorp's and Energy West Mining Company's minimum contributions to the plans are based on the amount of wages paid to employees covered by the Local 57 Trust Fund collective bargaining agreements and the number of mining hours worked for the UMWA 1974 Pension Plan, respectively, subject to ERISA minimum funding requirements. As a result of the plan's critical status, Energy West Mining Company was required to begin paying a surcharge for hours worked on and after December 1, 2014. (2) For the UMWA 1974 Pension Plan, information is for plan years beginning July 1, 2015, 2014 and 2013. Information for the plan year beginning July 1, 2016 is not yet available. For the Local 57 Trust Fund, information is for plan years beginning July 1, 2015, 2014 and 2013. Information for the plan year beginning July 1, 2016 is not yet available. The current collective bargaining agreements governing the Local 57 Trust Fund expire in 2020. Defined Contribution Plan PacifiCorp's 401(k) plan covers substantially all employees. PacifiCorp's matching contributions are based on each participant's level of contribution and, as of January 1, 2017, all participants receive contributions based on eligible pre-tax annual compensation. Contributions cannot exceed the maximum allowable for tax purposes. PacifiCorp's contributions to the 401(k) plan were $39 million , $34 million and $35 million for the years ended December 31, 2017 , 2016 and 2015 , respectively.
MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee Benefit Plans [Text Block]	Employee Benefit Plans MidAmerican Energy sponsors a noncontributory defined benefit pension plan covering a majority of all employees of BHE and its domestic energy subsidiaries other than PacifiCorp and NV Energy, Inc. Benefit obligations under the plan are based on a cash balance arrangement for salaried employees and most union employees and final average pay formulas for other union employees. MidAmerican Energy also maintains noncontributory, nonqualified defined benefit supplemental executive retirement plans ("SERP") for certain active and retired participants. MidAmerican Energy also sponsors certain postretirement healthcare and life insurance benefits covering substantially all retired employees of BHE and its domestic energy subsidiaries other than PacifiCorp and NV Energy, Inc. Under the plans, a majority of all employees of the participating companies may become eligible for these benefits if they reach retirement age. New employees are not eligible for benefits under the plans. MidAmerican Energy has been allowed to recover accrued pension and other postretirement benefit costs in its electric and gas service rates. Net Periodic Benefit Cost For purposes of calculating the expected return on pension plan assets, a market-related value is used. The market-related value of plan assets is calculated by spreading the difference between expected and actual investment returns on equity investments over a five-year period beginning after the first year in which they occur. MidAmerican Energy bills to and is reimbursed currently for affiliates' share of the net periodic benefit costs from all plans in which such affiliates participate. In 2017 , 2016 and 2015 , MidAmerican Energy's share of the pension net periodic benefit cost (credit) was $(6) million , $(2) million and $(4) million , respectively. MidAmerican Energy's share of the other postretirement net periodic benefit cost (credit) in 2017 , 2016 and 2015 totaled $(1) million , $(1) million and $- million, respectively. Net periodic benefit cost for the plans of MidAmerican Energy and the aforementioned affiliates included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ 9 $ 10 $ 12 $ 5 $ 5 $ 7 Interest cost 31 34 32 9 10 9 Expected return on plan assets (44 ) (44 ) (46 ) (14 ) (13 ) (15 ) Net amortization 2 2 2 (4 ) (4 ) (3 ) Net periodic benefit (credit) cost $ (2 ) $ 2 $ — $ (4 ) $ (2 ) $ (2 ) Funded Status The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, beginning of year $ 684 $ 678 $ 252 $ 249 Employer contributions 7 7 1 1 Participant contributions — — 1 1 Actual return on plan assets 114 57 36 14 Benefits paid (60 ) (58 ) (13 ) (13 ) Plan assets at fair value, end of year $ 745 $ 684 $ 277 $ 252 The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Benefit obligation, beginning of year $ 773 $ 785 $ 233 $ 234 Service cost 9 10 5 5 Interest cost 31 34 9 10 Participant contributions — — 1 1 Actuarial loss (gain) 46 2 11 (4 ) Benefits paid (60 ) (58 ) (13 ) (13 ) Benefit obligation, end of year $ 799 $ 773 $ 246 $ 233 Accumulated benefit obligation, end of year $ 790 $ 764 The funded status of the plans and the amounts recognized on the Balance Sheets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, end of year $ 745 $ 684 $ 277 $ 252 Less - Benefit obligation, end of year 799 773 246 233 Funded status $ (54 ) $ (89 ) $ 31 $ 19 Amounts recognized on the Balance Sheets: Other assets $ 66 $ 26 $ 31 $ 19 Other current liabilities (8 ) (8 ) — — Other liabilities (112 ) (107 ) — — Amounts recognized $ (54 ) $ (89 ) $ 31 $ 19 The SERP has no plan assets; however, MidAmerican Energy has Rabbi trusts that hold corporate-owned life insurance and other investments to provide funding for the future cash requirements of the SERP. The cash surrender value of all of the policies included in the Rabbi trusts, net of amounts borrowed against the cash surrender value, plus the fair market value of other Rabbi trust investments, was $118 million and $110 million as of December 31, 2017 and 2016 , respectively. These assets are not included in the plan assets in the above table, but are reflected in investments and restricted cash and investments on the Balance Sheets. Unrecognized Amounts The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Net (gain) loss $ (11 ) $ 15 $ 23 $ 36 Prior service cost (credit) 1 1 (25 ) (31 ) Total $ (10 ) $ 16 $ (2 ) $ 5 MidAmerican Energy sponsors pension and other postretirement benefit plans on behalf of certain of its affiliates in addition to itself, and therefore, the portion of the funded status of the respective plans that has not yet been recognized in net periodic benefit cost is attributable to multiple entities. Additionally, substantially all of MidAmerican Energy's portion of such amounts is either refundable to or recoverable from its customers and is reflected as regulatory liabilities and regulatory assets. A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2017 and 2016 is as follows (in millions): Regulatory Asset Regulatory Liability Receivables (Payables) with Affiliates Total Pension Balance, December 31, 2015 $ 22 $ — $ 6 $ 28 Net loss (gain) arising during the year 1 (11 ) — (10 ) Net amortization (1 ) (1 ) — (2 ) Total — (12 ) — (12 ) Balance, December 31, 2016 22 (12 ) 6 16 Net loss (gain) arising during the year 4 (29 ) 1 (24 ) Net amortization (2 ) — — (2 ) Total 2 (29 ) 1 (26 ) Balance, December 31, 2017 $ 24 $ (41 ) $ 7 $ (10 ) Regulatory Asset Receivables (Payables) with Affiliates Total Other Postretirement Balance, December 31, 2015 $ 17 $ (11 ) $ 6 Net gain arising during the year (2 ) (3 ) (5 ) Net amortization 3 1 4 Total 1 (2 ) (1 ) Balance, December 31, 2016 18 (13 ) 5 Net gain arising during the year (7 ) (4 ) (11 ) Net amortization 3 1 4 Total (4 ) (3 ) (7 ) Balance, December 31, 2017 $ 14 $ (16 ) $ (2 ) The net loss and prior service cost (credit) that will be amortized in 2018 into net periodic benefit cost are estimated to be as follows (in millions): Net Loss Prior Service Cost (Credit) Total Pension $ 1 $ 1 $ 2 Other postretirement 1 (5 ) (4 ) Total $ 2 $ (4 ) $ (2 ) Plan Assumptions Assumptions used to determine benefit obligations and net periodic benefit cost were as follows: Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Benefit obligations as of December 31: Discount rate 3.60 % 4.10 % 4.50 % 3.50 % 3.90 % 4.25 % Rate of compensation increase 2.75 % 2.75 % 2.75 % N/A N/A N/A Net periodic benefit cost for the years ended December 31: Discount rate 4.10 % 4.50 % 4.00 % 3.90 % 4.25 % 3.75 % Expected return on plan assets (1) 6.75 % 7.00 % 7.25 % 6.50 % 6.75 % 7.00 % Rate of compensation increase 2.75 % 2.75 % 2.75 % N/A N/A N/A (1) Amounts reflected are pre-tax values. Assumed after-tax returns for a taxable, non-union other postretirement plan were 4.81% for 2017 , and 5.00% for 2016 , and 5.18% for 2015 . In establishing its assumption as to the expected return on plan assets, MidAmerican Energy utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets. 2017 2016 Assumed healthcare cost trend rates as of December 31: Healthcare cost trend rate assumed for next year 7.10 % 7.40 % Rate that the cost trend rate gradually declines to 5.00 % 5.00 % Year that the rate reaches the rate it is assumed to remain at 2025 2025 A one percentage-point change in assumed healthcare cost trend rates would have the following effects (in millions): One Percentage-Point Increase Decrease Increase (decrease) in: Total service and interest cost for the year ended December 31, 2017 $ — $ — Other postretirement benefit obligation as of December 31, 2017 3 (3 ) Contributions and Benefit Payments Employer contributions to the pension and other postretirement benefit plans are expected to be $8 million and $1 million , respectively, during 2018 . Funding to MidAmerican Energy's pension benefit plan trust is based upon the actuarially determined costs of the plan and the requirements of the Internal Revenue Code, the Employee Retirement Income Security Act of 1974 and the Pension Protection Act of 2006, as amended. MidAmerican Energy considers contributing additional amounts from time to time in order to achieve certain funding levels specified under the Pension Protection Act of 2006, as amended. MidAmerican Energy's funding policy for its other postretirement benefit plan is to generally contribute amounts consistent with its rate regulatory arrangements. Net periodic benefit costs assigned to MidAmerican Energy affiliates are reimbursed currently in accordance with its intercompany administrative services agreement. The expected benefit payments to participants in MidAmerican Energy's pension and other postretirement benefit plans for 2017 through 2021 and for the five years thereafter are summarized below (in millions): Projected Benefit Payments Pension Other Postretirement 2018 $ 60 $ 19 2019 61 20 2020 60 21 2021 59 22 2022 57 21 2023-2027 256 98 Plan Assets Investment Policy and Asset Allocations MidAmerican Energy's investment policy for its pension and other postretirement benefit plans is to balance risk and return through a diversified portfolio of debt securities, equity securities and other alternative investments. Maturities for debt securities are managed to targets consistent with prudent risk tolerances. The plans retain outside investment advisors to manage plan investments within the parameters outlined by the MidAmerican Energy Pension and Employee Benefits Plans Administrative Committee. The investment portfolio is managed in line with the investment policy with sufficient liquidity to meet near-term benefit payments. The target allocations (percentage of plan assets) for MidAmerican Energy's pension and other postretirement benefit plan assets are as follows as of December 31, 2017 : Pension Other Postretirement % % Debt securities (1) 20-50 25-45 Equity securities (1) 60-80 45-80 Real estate funds 2-8 — Other 0-3 0-5 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities. Fair Value Measurements The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit pension plan (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ — $ 17 $ — $ 17 Debt securities: United States government obligations 21 — — 21 Corporate obligations — 59 — 59 Municipal obligations — 7 — 7 Agency, asset and mortgage-backed obligations — 33 — 33 Equity securities: United States companies 137 — — 137 International equity securities 44 — — 44 Investment funds (2) 74 — — 74 Total assets in the hierarchy $ 276 $ 116 $ — 392 Investment funds (2) measured at net asset value 315 Real estate funds measured at net asset value 38 Total assets measured at fair value $ 745 As of December 31, 2016: Cash equivalents $ — $ 17 $ — $ 17 Debt securities: United States government obligations 9 — — 9 Corporate obligations — 53 — 53 Municipal obligations — 6 — 6 Agency, asset and mortgage-backed obligations — 22 — 22 Equity securities: United States companies 130 — — 130 International equity securities 39 — — 39 Investment funds (2) 63 — — 63 Total assets in the hierarchy $ 241 $ 98 $ — 339 Investment funds (2) measured at net asset value 295 Real estate funds measured at net asset value 50 Total assets measured at fair value $ 684 (1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 69% and 31% , respectively, for 2017 and 74% and 26% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 72% and 28% , respectively, for 2017 and 71% and 29% , respectively, for 2016 . The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit other postretirement plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 6 $ — $ — $ 6 Debt securities: United States government obligations 5 — — 5 Corporate obligations — 14 — 14 Municipal obligations — 44 — 44 Agency, asset and mortgage-backed obligations — 12 — 12 Equity securities: United States companies 84 — — 84 Investment funds (2) 112 — — 112 Total assets measured at fair value $ 207 $ 70 $ — $ 277 As of December 31, 2016: Cash equivalents $ 10 $ — $ — $ 10 Debt securities: United States government obligations 5 — — 5 Corporate obligations — 11 — 11 Municipal obligations — 37 — 37 Agency, asset and mortgage-backed obligations — 11 — 11 Equity securities: United States companies 122 — — 122 Investment funds (2) 56 — — 56 Total assets measured at fair value $ 193 $ 59 $ — $ 252 (1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 81% and 19% , respectively, for 2017 and 70% and 30% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 42% and 58% , respectively, for 2017 and 30% and 70% , respectively, for 2016 . For level 1 investments, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. For level 2 investments, the fair value is determined using pricing models based on observable market inputs. Shares of mutual funds not registered under the Securities Act of 1933, private equity limited partnership interests, common and commingled trust funds and investment entities are reported at fair value based on the net asset value per unit, which is used for expedience purposes. A fund's net asset value is based on the fair value of the underlying assets held by the fund less its liabilities. MidAmerican Energy sponsors a defined contribution plan ("401(k) plan") covering substantially all employees. MidAmerican Energy's matching contributions are based on each participant's level of contribution, and certain participants receive contributions based on eligible pre-tax annual compensation. Contributions cannot exceed the maximum allowable for tax purposes. Certain participants now receive enhanced benefits in the 401(k) plan and no longer accrue benefits in the noncontributory defined benefit pension plans. MidAmerican Energy's contributions to the plan were $20 million , $20 million , and $20 million for the years ended December 31, 2017 , 2016 and 2015 , respectively.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Defined Benefit Plan Disclosure [Line Items]
Employee Benefit Plans [Text Block]	Employee Benefit Plans Refer to Note 11 of MidAmerican Energy's Notes to Financial Statements for additional information regarding MidAmerican Funding's pension, supplemental retirement and postretirement benefit plans. Pension and postretirement costs allocated by MidAmerican Funding to its parent and other affiliates in each of the years ended December 31, were as follows (in millions): 2017 2016 2015 Pension costs $ 4 $ 4 $ 4 Other postretirement costs (3 ) (1 ) (2 )

Retirement Plan and Postretirem

Retirement Plan and Postretirement Benefits Retirement Plan and Postretirement Benefits (Notes)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee Benefit Plans [Text Block]	Employee Benefit Plans Defined Benefit Plans Domestic Operations PacifiCorp, MidAmerican Energy and NV Energy sponsor defined benefit pension plans that cover a majority of all employees of BHE and its domestic energy subsidiaries. These pension plans include noncontributory defined benefit pension plans, supplemental executive retirement plans ("SERP") and a restoration plan for certain executives of NV Energy. PacifiCorp, MidAmerican Energy and NV Energy also provide certain postretirement healthcare and life insurance benefits through various plans to eligible retirees. Net Periodic Benefit Cost For purposes of calculating the expected return on plan assets, a market-related value is used. The market-related value of plan assets is calculated by spreading the difference between expected and actual investment returns over a five-year period beginning after the first year in which they occur. Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ 24 $ 29 $ 33 $ 9 $ 9 $ 11 Interest cost 116 126 121 29 31 31 Expected return on plan assets (160 ) (160 ) (169 ) (40 ) (41 ) (45 ) Net amortization 25 46 53 (14 ) (12 ) (11 ) Net periodic benefit cost (credit) $ 5 $ 41 $ 38 $ (16 ) $ (13 ) $ (14 ) Funded Status The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, beginning of year $ 2,525 $ 2,489 $ 666 $ 662 Employer contributions 64 78 5 2 Participant contributions — — 10 10 Actual return on plan assets 390 163 106 41 Settlement (15 ) (11 ) — — Benefits paid (203 ) (194 ) (51 ) (49 ) Plan assets at fair value, end of year $ 2,761 $ 2,525 $ 736 $ 666 The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Benefit obligation, beginning of year $ 2,952 $ 2,934 $ 734 $ 740 Service cost 24 29 9 9 Interest cost 116 126 29 31 Participant contributions — — 10 10 Actuarial loss (gain) 132 67 (10 ) (7 ) Amendment — 1 — — Settlement (15 ) (11 ) — — Benefits paid (203 ) (194 ) (51 ) (49 ) Benefit obligation, end of year $ 3,006 $ 2,952 $ 721 $ 734 Accumulated benefit obligation, end of year $ 2,988 $ 2,929 The funded status of the plans and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, end of year $ 2,761 $ 2,525 $ 736 $ 666 Benefit obligation, end of year 3,006 2,952 721 734 Funded status $ (245 ) $ (427 ) $ 15 $ (68 ) Amounts recognized on the Consolidated Balance Sheets: Other assets $ 66 $ 26 $ 32 $ 19 Other current liabilities (14 ) (15 ) — — Other long-term liabilities (297 ) (438 ) (17 ) (87 ) Amounts recognized $ (245 ) $ (427 ) $ 15 $ (68 ) The SERPs and restoration plan have no plan assets; however, the Company has Rabbi trusts that hold corporate-owned life insurance and other investments to provide funding for the future cash requirements of the SERPs and restoration plan. The cash surrender value of all of the policies included in the Rabbi trusts, net of amounts borrowed against the cash surrender value, plus the fair market value of other Rabbi trust investments, was $272 million and $242 million as of December 31, 2017 and 2016 , respectively. These assets are not included in the plan assets in the above table, but are reflected in noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of plan assets, projected benefit obligation and accumulated benefit obligation for (1) pension and other postretirement benefit plans with a projected benefit obligation in excess of the fair value of plan assets and (2) pension plans with an accumulated benefit obligation in excess of the fair value of plan assets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Fair value of plan assets $ 2,016 $ 1,841 $ 126 $ 413 Projected benefit obligation $ 2,327 $ 2,294 $ 143 $ 500 Accumulated benefit obligation $ 2,316 $ 2,278 Unrecognized Amounts The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Net loss $ 649 $ 775 $ 14 $ 88 Prior service credit (3 ) (7 ) (37 ) (52 ) Regulatory deferrals (4 ) (7 ) 7 7 Total $ 642 $ 761 $ (16 ) $ 43 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2017 and 2016 is as follows (in millions): Accumulated Other Regulatory Regulatory Comprehensive Asset Liability Loss Total Pension Balance, December 31, 2015 $ 729 $ (1 ) $ 13 $ 741 Net loss (gain) arising during the year 76 (11 ) — 65 Net prior service cost arising during the year 1 — — 1 Net amortization (45 ) (1 ) — (46 ) Total 32 (12 ) — 20 Balance, December 31, 2016 761 (13 ) 13 761 Net (gain) loss arising during the year (68 ) (29 ) 3 (94 ) Net amortization (28 ) (1 ) 4 (25 ) Total (96 ) (30 ) 7 (119 ) Balance, December 31, 2017 $ 665 $ (43 ) $ 20 $ 642 Regulatory Regulatory Asset Liability Total Other Postretirement Balance, December 31, 2015 $ 49 $ (12 ) $ 37 Net gain arising during the year (5 ) (1 ) (6 ) Net amortization 11 1 12 Total 6 — 6 Balance, December 31, 2016 55 (12 ) 43 Net gain arising during the year (52 ) (21 ) (73 ) Net amortization 7 7 14 Total (45 ) (14 ) (59 ) Balance, December 31, 2017 $ 10 $ (26 ) $ (16 ) The net loss, prior service credit and regulatory deferrals that will be amortized in 2018 into net periodic benefit cost are estimated to be as follows (in millions): Net Prior Service Regulatory Loss Credit Deferrals Total Pension $ 32 $ (1 ) $ (3 ) $ 28 Other postretirement 1 (15 ) 1 (13 ) Total $ 33 $ (16 ) $ (2 ) $ 15 Plan Assumptions Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost were as follows: Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Benefit obligations as of December 31: Discount rate 3.60 % 4.06 % 4.43 % 3.57 % 4.01 % 4.33 % Rate of compensation increase 2.75 % 2.75 % 2.75 % NA NA NA Net periodic benefit cost for the years ended December 31: Discount rate 4.06 % 4.43 % 4.00 % 4.01 % 4.33 % 3.93 % Expected return on plan assets 6.55 % 6.78 % 6.88 % 6.73 % 7.03 % 7.00 % Rate of compensation increase 2.75 % 2.75 % 2.75 % NA NA NA In establishing its assumption as to the expected return on plan assets, the Company utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets. 2017 2016 Assumed healthcare cost trend rates as of December 31: Healthcare cost trend rate assumed for next year 7.10 % 7.40 % Rate that the cost trend rate gradually declines to 5.00 % 5.00 % Year that the rate reaches the rate it is assumed to remain at 2025 2025 A one percentage-point change in assumed healthcare cost trend rates would have the following effects (in millions): One Percentage-Point Increase Decrease Increase (decrease) in: Total service and interest cost for the year ended December 31, 2017 $ — $ — Other postretirement benefit obligation as of December 31, 2017 4 (4 ) Contributions and Benefit Payments Employer contributions to the pension and other postretirement benefit plans are expected to be $39 million and $3 million , respectively, during 2018 . Funding to the established pension trusts is based upon the actuarially determined costs of the plans and the requirements of the Internal Revenue Code, the Employee Retirement Income Security Act of 1974 and the Pension Protection Act of 2006, as amended. The Company considers contributing additional amounts from time to time in order to achieve certain funding levels specified under the Pension Protection Act of 2006, as amended. The Company's funding policy for its other postretirement benefit plans is to generally contribute an amount equal to the net periodic benefit cost. The expected benefit payments to participants in the Company's pension and other postretirement benefit plans for 2018 through 2022 and for the five years thereafter are summarized below (in millions): Projected Benefit Payments Other Pension Postretirement 2018 $ 226 $ 54 2019 224 55 2020 224 57 2021 222 55 2022 214 54 2023-2027 979 243 Plan Assets Investment Policy and Asset Allocations The Company's investment policy for its pension and other postretirement benefit plans is to balance risk and return through a diversified portfolio of debt securities, equity securities and other alternative investments. Maturities for debt securities are managed to targets consistent with prudent risk tolerances. The plans retain outside investment advisors to manage plan investments within the parameters outlined by each plan's Pension and Employee Benefits Plans Administrative Committee. The investment portfolio is managed in line with the investment policy with sufficient liquidity to meet near-term benefit payments. The target allocations (percentage of plan assets) for the Company's pension and other postretirement benefit plan assets are as follows as of December 31, 2017 : Other Pension Postretirement % % PacifiCorp: Debt securities (1) 33-38 33-37 Equity securities (1) 49-60 61-65 Limited partnership interests 7-12 1-3 Other 0-1 0-1 MidAmerican Energy: Debt securities (1) 20-50 25-45 Equity securities (1) 60-80 45-80 Real estate funds 2-8 — Other 0-3 0-5 NV Energy: Debt securities (1) 53-77 40 Equity securities (1) 23-47 60 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities. Fair Value Measurements The following table presents the fair value of plan assets, by major category, for the Company's defined benefit pension plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 10 $ 76 $ — $ 86 Debt securities: United States government obligations 218 — — 218 Corporate obligations — 350 — 350 Municipal obligations — 16 — 16 Agency, asset and mortgage-backed obligations — 110 — 110 Equity securities: United States companies 622 — — 622 International companies 136 — — 136 Investment funds (2) 83 20 — 103 Total assets in the fair value hierarchy $ 1,069 $ 572 $ — 1,641 Investment funds (2) measured at net asset value 1,019 Limited partnership interests (3) measured at net asset value 63 Real estate funds measured at net asset value 38 Total assets measured at fair value $ 2,761 As of December 31, 2016: Cash equivalents $ 4 $ 54 $ — $ 58 Debt securities: United States government obligations 161 — — 161 International government obligations — 2 — 2 Corporate obligations — 295 — 295 Municipal obligations — 20 — 20 Agency, asset and mortgage-backed obligations — 112 — 112 Equity securities: United States companies 583 — — 583 International companies 117 — — 117 Investment funds (2) 146 — — 146 Total assets in the fair value hierarchy $ 1,011 $ 483 $ — 1,494 Investment funds (2) measured at net asset value 920 Limited partnership interests (3) measured at net asset value 61 Real estate funds measured at net asset value 50 Total assets measured at fair value $ 2,525 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 62% and 38% , respectively, for both 2017 and 2016 . Additionally, these funds are invested in United States and international securities of approximately 68% and 32% , respectively, for 2017 and 60% and 40% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of plan assets, by major category, for the Company's defined benefit other postretirement plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 11 $ 3 $ — $ 14 Debt securities: United States government obligations 20 — — 20 Corporate obligations — 36 — 36 Municipal obligations — 46 — 46 Agency, asset and mortgage-backed obligations — 29 — 29 Equity securities: United States companies 185 — — 185 International companies 8 — — 8 Investment funds 219 1 — 220 Total assets in the fair value hierarchy $ 443 $ 115 $ — 558 Investment funds measured at net asset value 174 Limited partnership interests measured at net asset value 4 Total assets measured at fair value $ 736 As of December 31, 2016: Cash equivalents $ 18 $ 2 $ — $ 20 Debt securities: United States government obligations 19 — — 19 Corporate obligations — 29 — 29 Municipal obligations — 39 — 39 Agency, asset and mortgage-backed obligations — 25 — 25 Equity securities: United States companies 217 — — 217 International companies 5 — — 5 Investment funds (2) 152 — — 152 Total assets in the fair value hierarchy $ 411 $ 95 $ — 506 Investment funds (2) measured at net asset value 156 Limited partnership interests (3) measured at net asset value 4 Total assets measured at fair value $ 666 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 68% and 32% , respectively, for 2017 and 63% and 37% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 73% and 27% , respectively, for 2017 and 72% and 28% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. For level 1 investments, a readily observable quoted market price or net asset value of an identical security in an active market is used to record the fair value. For level 2 investments, the fair value is determined using pricing models based on observable market inputs. Shares of mutual funds not registered under the Securities Act of 1933, private equity limited partnership interests, common and commingled trust funds and investment entities are reported at fair value based on the net asset value per unit, which is used for expedience purposes. A fund's net asset value is based on the fair value of the underlying assets held by the fund less its liabilities. Foreign Operations Certain wholly-owned subsidiaries of Northern Powergrid participate in the Northern Powergrid group of the United Kingdom industry-wide Electricity Supply Pension Scheme (the "UK Plan"), which provides pension and other related defined benefits, based on final pensionable pay, to the majority of the employees of Northern Powergrid . The UK Plan is closed to employees hired after July 23, 1997. Employees hired after that date are covered by a defined contribution plan sponsored by a wholly-owned subsidiary of Northern Powergrid . Net Periodic Benefit Cost For purposes of calculating the expected return on pension plan assets, a market-related value is used. The market-related value of plan assets is calculated by spreading the difference between expected and actual investment returns over a five-year period beginning after the first year in which they occur. Net periodic benefit cost for the UK Plan included the following components for the years ended December 31 (in millions): 2017 2016 2015 Service cost $ 23 $ 20 $ 24 Interest cost 58 72 79 Expected return on plan assets (100 ) (110 ) (116 ) Settlement 31 — — Net amortization 63 44 62 Net periodic benefit cost $ 75 $ 26 $ 49 Funded Status The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): 2017 2016 Plan assets at fair value, beginning of year $ 2,169 $ 2,276 Employer contributions 58 55 Participant contributions 1 1 Actual return on plan assets 145 349 Settlement (144 ) — Benefits paid (68 ) (115 ) Foreign currency exchange rate changes 207 (397 ) Plan assets at fair value, end of year $ 2,368 $ 2,169 The following table is a reconciliation of the benefit obligation for the years ended December 31 (in millions): 2017 2016 Benefit obligation, beginning of year $ 2,125 $ 2,142 Service cost 23 20 Interest cost 58 72 Participant contributions 1 1 Actuarial loss (gain) (4 ) 387 Settlement (131 ) — Benefits paid (68 ) (115 ) Foreign currency exchange rate changes 197 (382 ) Benefit obligation, end of year $ 2,201 $ 2,125 Accumulated benefit obligation, end of year $ 1,933 $ 1,858 The funded status of the UK Plan and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): 2017 2016 Plan assets at fair value, end of year $ 2,368 $ 2,169 Benefit obligation, end of year 2,201 2,125 Funded status $ 167 $ 44 Amounts recognized on the Consolidated Balance Sheets: Other assets $ 167 $ 44 Unrecognized Amounts The portion of the funded status of the UK Plan not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): 2017 2016 Net loss $ 510 $ 590 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost, which are included in accumulated other comprehensive loss on the Consolidated Balance Sheets, for the years ended December 31 is as follows (in millions): 2017 2016 Balance, beginning of year $ 590 $ 592 Net (gain) loss arising during the year (50 ) 148 Settlement (17 ) — Net amortization (63 ) (44 ) Foreign currency exchange rate changes 50 (106 ) Total (80 ) (2 ) Balance, end of year $ 510 $ 590 The net loss that will be amortized from accumulated other comprehensive loss in 2018 into net periodic benefit cost is estimated to be $60 million . Plan Assumptions Assumptions used to determine benefit obligations and net periodic benefit cost were as follows: 2017 2016 2015 Benefit obligations as of December 31: Discount rate 2.60 % 2.70 % 3.70 % Rate of compensation increase 3.45 % 3.00 % 2.90 % Rate of future price inflation 2.95 % 3.00 % 2.90 % Net periodic benefit cost for the years ended December 31: Discount rate 2.70 % 3.70 % 3.60 % Expected return on plan assets 5.00 % 5.60 % 5.60 % Rate of compensation increase 3.00 % 2.90 % 2.80 % Rate of future price inflation 3.00 % 2.90 % 2.80 % Contributions and Benefit Payments Employer contributions to the UK Plan are expected to be £45 million during 2018 . The expected benefit payments to participants in the UK Plan for 2018 through 2022 and for the five years thereafter excluding lump sum settlement elections, using the foreign currency exchange rate as of December 31, 2017 , are summarized below (in millions): 2018 $ 72 2019 74 2020 75 2021 77 2022 79 2023-2027 427 Plan Assets Investment Policy and Asset Allocations The investment policy for the UK Plan is to balance risk and return through a diversified portfolio of debt securities, equity securities, real estate and other asset classes. Maturities for debt securities are managed to targets consistent with prudent risk tolerances. The UK Plan retains outside investment advisors to manage plan investments within the parameters set by the trustees of the UK Plan in consultation with Northern Powergrid . The investment portfolio is managed in line with the investment policy with sufficient liquidity to meet near-term benefit payments. The return on assets assumption is based on a weighted-average of the expected historical performance for the types of assets in which the UK Plan invests. The target allocations (percentage of plan assets) for the UK Plan assets are as follows as of December 31, 2017 : % Debt securities (1) 50-55 Equity securities (1) 35-40 Real estate funds and other 5-15 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds have been allocated based on the underlying investments in debt and equity securities. Fair Value Measurements The following table presents the fair value of the UK Plan assets, by major category (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 4 $ 30 $ — $ 34 Debt securities: United Kingdom government obligations 870 — — 870 Equity securities: Investment funds (2) — 1,027 — 1,027 Real estate funds — — 230 230 Total $ 874 $ 1,057 $ 230 2,161 Investment funds (2) measured at net asset value 207 Total assets measured at fair value $ 2,368 As of December 31, 2016: Cash equivalents $ 4 $ 83 $ — $ 87 Debt securities: United Kingdom government obligations 718 — — 718 Equity securities: Investment funds (2) — 1,095 — 1,095 Real estate funds — — 105 105 Total $ 722 $ 1,178 $ 105 2,005 Investment funds (2) measured at net asset value 164 Total assets measured at fair value $ 2,169 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 21% and 79% , respectively, for 2017 and 44% and 56% , respectively, for 2016 . The fair value of the UK Plan's assets are determined similar to the plan assets of the domestic plans as previously discussed. The following table reconciles the beginning and ending balances of the UK Plan assets measured at fair value using significant Level 3 inputs for the years ended December 31 (in millions): Real Estate Funds 2017 2016 2015 Beginning balance $ 105 $ 204 $ 199 Actual return on plan assets still held at period end 6 10 18 Purchases (sales) 104 (80 ) — Foreign currency exchange rate changes 15 (29 ) (13 ) Ending balance $ 230 $ 105 $ 204 Defined Contribution Plans The Company sponsors various defined contribution plans covering substantially all employees. The Company's contributions vary depending on the plan, but matching contributions are based on each participant's level of contribution, and certain participants receive contributions based on eligible pre-tax annual compensation. Contributions cannot exceed the maximum allowable for tax purposes. The Company's contributions to these plans were $103 million , $102 million and $90 million for the years ended December 31, 2017 , 2016 and 2015 , respectively.
Nevada Power Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee Benefit Plans [Text Block]	Retirement Plan and Postretirement Benefits Nevada Power is a participant in benefit plans sponsored by NV Energy . The NV Energy Retirement Plan includes a qualified pension plan ("Qualified Pension Plan") and a supplemental executive retirement plan and a restoration plan (collectively, "Non‑Qualified Pension Plans") that provide pension benefits for eligible employees. The NV Energy Comprehensive Welfare Benefit and Cafeteria Plan provides certain postretirement health care and life insurance benefits for eligible retirees ("Other Postretirement Plans") on behalf of Nevada Power . Nevada Power contributed $1 million , $36 million and $- million to the Qualified Pension Plan for the year ended December 31 , 2017 , 2016 and 2015 , respectively. Nevada Power contributed $ 1 million , $- million and $- million to the Non-Qualified Pension Plans for the year ended December 31 , 2017 , 2016 and 2015 , respectively. Nevada Power did not make any contributions to the Other Postretirement Plans for the year ended December 31 , 2017 , 2016 and 2015 . Amounts attributable to Nevada Power were allocated from NV Energy based upon the current, or in the case of retirees, previous, employment location. Offsetting regulatory assets and liabilities have been recorded related to the amounts not yet recognized as a component of net periodic benefit costs that will be included in regulated rates. Net periodic benefit costs not included in regulated rates are included in accumulated other comprehensive loss, net. Amounts receivable from (payable to) NV Energy are included on the Consolidated Balance Sheets and consist of the following as of December 31 (in millions): 2017 2016 Qualified Pension Plan - Other long-term liabilities $ (23 ) $ (24 ) Non-Qualified Pension Plans: Other current liabilities (1 ) (1 ) Other long-term liabilities (10 ) (9 ) Other Postretirement Plans - Other long-term liabilities 1 (4 )
Sierra Pacific Power Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee Benefit Plans [Text Block]	Retirement Plan and Postretirement Benefits Sierra Pacific is a participant in benefit plans sponsored by NV Energy . The NV Energy Retirement Plan includes a qualified pension plan ("Qualified Pension Plan") and a supplemental executive retirement plan and a restoration plan (collectively, "Non‑Qualified Pension Plans") that provide pension benefits for eligible employees. The NV Energy Comprehensive Welfare Benefit and Cafeteria Plan provides certain postretirement health care and life insurance benefits for eligible retirees ("Other Postretirement Plans") on behalf of Sierra Pacific . Sierra Pacific contributed $1 million , $27 million and $- million to the Qualified Pension Plan for the year ended December 31 , 2017 , 2016 and 2015 , respectively. For the Other Postretirement Plans, Sierra Pacific contributed $4 million , $ 1 million and $- million for the year ended December 31 , 2017 , 2016 and 2015 , respectively. Sierra Pacific contributed $ 1 million , $- million and $- million to the Non-Qualified Pension Plans for the year ended December 31 , 2017 , 2016 and 2015 , respectively. Amounts attributable to Sierra Pacific were allocated from NV Energy based upon the current, or in the case of retirees, previous, employment location. Offsetting regulatory assets and liabilities have been recorded related to the amounts not yet recognized as a component of net periodic benefit costs that will be included in regulated rates. Net periodic benefit costs not included in regulated rates are included in accumulated other comprehensive loss, net. Amounts payable to NV Energy are included on the Consolidated Balance Sheets and consist of the following as of December 31 (in millions): 2017 2016 Qualified Pension Plan - Other long-term liabilities $ (2 ) $ (12 ) Non-Qualified Pension Plans: Other current liabilities (1 ) (1 ) Other long-term liabilities (8 ) (9 ) Other Postretirement Plans - Other long-term liabilities (20 ) (28 )

Asset Retirement Obligations (N

Asset Retirement Obligations (Notes)	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations [Text Block]	Asset Retirement Obligations The Company estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work. The Company does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Consolidated Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $2.3 billion and $2.2 billion as of December 31, 2017 and 2016 , respectively. The following table presents the Company's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Fossil fuel facilities $ 380 $ 404 Quad Cities Station 342 343 Wind generating facilities 138 124 Offshore pipeline facilities 32 33 Solar generating facilities 19 12 Other 43 38 Total asset retirement obligations $ 954 $ 954 Quad Cities Station nuclear decommissioning trust funds $ 515 $ 460 The following table reconciles the beginning and ending balances of the Company's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 954 $ 921 Change in estimated costs (18 ) 33 Additions 21 25 Retirements (45 ) (63 ) Accretion 42 38 Ending balance $ 954 $ 954 Reflected as: Other current liabilities $ 60 $ 98 Other long-term liabilities 894 856 Total ARO liability $ 954 $ 954 The Nuclear Regulatory Commission regulates the decommissioning of nuclear power plants, which includes the planning and funding for the decommissioning. In accordance with these regulations, MidAmerican Energy submits a biennial report to the Nuclear Regulatory Commission providing reasonable assurance that funds will be available to pay for its share of the Quad Cities Station decommissioning. Certain of the Company's decommissioning and reclamation obligations relate to jointly owned facilities and mine sites, and as such, each subsidiary is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, the respective subsidiary may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. The Company's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities. The changes in estimated costs for 2017 and 2016 were primarily due to new decommissioning studies conducted by the operator of the Quad Cities Station that changed the estimated amount and timing of cash flows.
PacifiCorp [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations [Text Block]	Asset Retirement Obligations PacifiCorp estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work. PacifiCorp does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Consolidated Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. Cost of removal regulatory liabilities totaled $955 million and $917 million as of December 31, 2017 and 2016 , respectively. The following table reconciles the beginning and ending balances of PacifiCorp's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 215 $ 224 Change in estimated costs (8 ) 2 Additions 6 — Retirements (6 ) (19 ) Accretion 8 8 Ending balance $ 215 $ 215 Reflected as: Other current liabilities $ 25 $ 21 Other long-term liabilities 190 194 $ 215 $ 215 Certain of PacifiCorp's decommissioning and reclamation obligations relate to jointly owned facilities and mine sites. PacifiCorp is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, PacifiCorp may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. PacifiCorp's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities.
MidAmerican Energy Company [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations [Text Block]	Asset Retirement Obligations MidAmerican Energy estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work. MidAmerican Energy does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $688 million and $665 million as of December 31, 2017 and 2016 , respectively. The following table presents MidAmerican Energy's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Quad Cities Station $ 342 $ 343 Fossil-fueled generating facilities 113 132 Wind-powered generating facilities 103 91 Other 1 1 Total asset retirement obligations $ 559 $ 567 Quad Cities Station nuclear decommissioning trust funds (1) $ 515 $ 460 (1) Refer to Note 7 for a discussion of the Quad Cities Station nuclear decommissioning trust funds. The following table reconciles the beginning and ending balances of MidAmerican Energy's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 567 $ 532 Change in estimated costs (14 ) 28 Additions 8 14 Retirements (26 ) (32 ) Accretion 24 25 Ending balance $ 559 $ 567 Reflected as: Other current liabilities $ 31 $ 57 Asset retirement obligations 528 510 $ 559 $ 567 The changes in estimated costs for 2017 and 2016 were primarily due to new decommissioning studies conducted by the operator of Quad Cities Station that changed the estimated amount and timing of cash flows.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations [Text Block]	Asset Retirement Obligations Refer to Note 12 of MidAmerican Energy's Notes to Financial Statements.
Nevada Power Company [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations [Text Block]	Asset Retirement Obligations Nevada Power estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work. Nevada Power does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Consolidated Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $307 million and $294 million as of December 31 , 2017 and 2016 , respectively. The following table presents Nevada Power 's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Waste water remediation $ 39 $ 38 Evaporative ponds and dry ash landfills 11 22 Asbestos 3 4 Solar 3 2 Other 24 17 Total asset retirement obligations $ 80 $ 83 The following table reconciles the beginning and ending balances of Nevada Power 's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 83 $ 85 Change in estimated costs 6 4 Retirements (13 ) (10 ) Accretion 4 4 Ending balance $ 80 $ 83 Reflected as: Other current liabilities $ 4 $ 20 Other long-term liabilities 76 63 $ 80 $ 83 In 2008, Nevada Power signed an administrative order of consent as owner and operator of Reid Gardner Generating Station Unit Nos. 1, 2 and 3 and as co-owner and operating agent of Unit No. 4. Based on the administrative order of consent, Nevada Power recorded estimated AROs and capital remediation costs. However, actual costs of work under the administrative order of consent may vary significantly once the scope of work is defined and additional site characterization has been completed. In connection with the termination of the co-ownership arrangement, effective October 22, 2013, between Nevada Power and California Department of Water Resources ("CDWR") for the Reid Gardner Generating Station Unit No. 4, Nevada Power and CDWR entered into a cost-sharing agreement that sets forth how the parties will jointly share in costs associated with all investigation, characterization and, if necessary, remedial activities as required under the administrative order of consent. Certain of Nevada Power 's decommissioning and reclamation obligations relate to jointly-owned facilities, and as such, Nevada Power is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, the respective subsidiary may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. Management has identified legal obligations to retire generation plant assets specified in land leases for Nevada Power 's jointly-owned Navajo Generating Station and the Higgins Generating Station. Provisions of the lease require the lessees to remove the facilities upon request of the lessors at the expiration of the leases. Nevada Power 's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities in other long-term liabilities on the Consolidated Balance Sheets.
Sierra Pacific Power Company [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations [Text Block]	Asset Retirement Obligations Sierra Pacific estimates its ARO liabilities based upon detailed engineering calculations of the amount and timing of the future cash spending for a third party to perform the required work. Spending estimates are escalated for inflation and then discounted at a credit-adjusted, risk-free rate. Changes in estimates could occur for a number of reasons, including changes in laws and regulations, plan revisions, inflation and changes in the amount and timing of the expected work. Sierra Pacific does not recognize liabilities for AROs for which the fair value cannot be reasonably estimated. Due to the indeterminate removal date, the fair value of the associated liabilities on certain generation, transmission, distribution and other assets cannot currently be estimated, and no amounts are recognized on the Consolidated Financial Statements other than those included in the cost of removal regulatory liability established via approved depreciation rates in accordance with accepted regulatory practices. These accruals totaled $211 million and $205 million as of December 31 , 2017 and 2016 , respectively. The following table presents Sierra Pacific 's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Asbestos $ 5 $ 4 Evaporative ponds and dry ash landfills 2 3 Other 3 3 Total asset retirement obligations $ 10 $ 10 The following table reconciles the beginning and ending balances of Sierra Pacific 's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 10 $ 10 Retirements — — Ending balance $ 10 $ 10 Reflected as: Other current liabilities $ — $ — Other long-term liabilities 10 10 $ 10 $ 10 Certain of Sierra Pacific 's decommissioning and reclamation obligations relate to jointly-owned facilities, and as such, Sierra Pacific is committed to pay a proportionate share of the decommissioning or reclamation costs. In the event of a default by any of the other joint participants, the respective subsidiary may be obligated to absorb, directly or by paying additional sums to the entity, a proportionate share of the defaulting party's liability. Sierra Pacific 's estimated share of the decommissioning and reclamation obligations are primarily recorded as ARO liabilities in other long-term liabilities on the Consolidated Balance Sheets.

Commitments and Contingencies (

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2017
Contractual Obligation [Line Items]
Commitments and Contingencies	Commitments and Contingencies Commitments The Company has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31, 2017 are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total Contract type: Fuel, capacity and transmission contract commitments $ 2,098 $ 1,637 $ 1,435 $ 1,210 $ 1,055 $ 10,044 $ 17,479 Construction commitments 1,120 57 5 — — — 1,182 Operating leases and easements 180 157 141 121 111 1,297 2,007 Maintenance, service and other contracts 246 249 238 231 253 1,055 2,272 $ 3,644 $ 2,100 $ 1,819 $ 1,562 $ 1,419 $ 12,396 $ 22,940 Fuel, Capacity and Transmission Contract Commitments The Utilities have fuel supply and related transportation and lime contracts for their coal- and natural gas-fueled generating facilities. The Utilities expect to supplement these contracts with additional contracts and spot market purchases to fulfill their future fossil fuel needs. The Utilities acquire a portion of their electricity through long-term purchases and exchange agreements. The Utilities have several power purchase agreements with renewable generating facilities that are not included in the table above as the payments are based on the amount of energy generated and there are no minimum payments. The Utilities also have contracts for the right to transmit electricity over other entities' transmission lines to facilitate delivery to their customers. MidAmerican Energy has long-term rail transportation contracts with BNSF Railway Company ("BNSF"), an affiliate company, and Union Pacific Railroad Company for the transportation of coal to all of the MidAmerican Energy-operated coal-fueled generating facilities. For the years ended December 31, 2017 , 2016 and 2015 , $109 million , $137 million and $185 million , respectively, were incurred for coal transportation services, the majority of which was related to the BNSF agreement. Construction Commitments The Company's firm construction commitments reflected in the table above include the following major construction projects: • MidAmerican Energy's construction of wind-powered generating facilities and the last of the four Multi-Value Projects approved by the Midcontinent Independent System Operator, Inc. for high voltage transmission lines in Iowa and Illinois in 2018. • ALP's investments in directly assigned transmission projects from the AESO . • PacifiCorp's costs associated with certain generating plant, transmission and distribution projects. Operating Leases and Easements The Company has non-cancelable operating leases primarily for office equipment, office space, certain operating facilities, land and rail cars. These leases generally require the Company to pay for insurance, taxes and maintenance applicable to the leased property. Certain leases contain renewal options for varying periods and escalation clauses for adjusting rent to reflect changes in price indices. The Company also has non-cancelable easements for land on which certain of its assets, primarily wind-powered generating facilities, are located. Rent expense on non-cancelable operating leases and easements totaled $156 million for both 2017 and 2016 and $146 million for 2015 . Maintenance, Service and Other Contracts The Company has entered into service agreements related to its nonregulated solar and wind-powered projects with third parties to operate and maintain the projects under fixed-fee operating and maintenance agreements. Additionally, t he Company has various non-cancelable maintenance, service and other contracts primarily related to turbine and equipment maintenance and various other service agreements. Legal Matters The Company is party to a variety of legal actions arising out of the normal course of business. Plaintiffs occasionally seek punitive or exemplary damages. The Company does not believe that such normal and routine litigation will have a material impact on its consolidated financial results. Environmental Laws and Regulations The Company is subject to federal, state, local and foreign laws and regulations regarding air and water quality, renewable portfolio standards, emissions performance standards, climate change, coal combustion byproduct disposal, hazardous and solid waste disposal, protected species and other environmental matters that have the potential to impact the Company's current and future operations. The Company believes it is in material compliance with all applicable laws and regulations. Hydroelectric Relicensing PacifiCorp's Klamath hydroelectric system is currently operating under annual licenses with the FERC. In February 2010, PacifiCorp, the United States Department of the Interior, the United States Department of Commerce, the state of California, the state of Oregon and various other governmental and non-governmental settlement parties signed the Klamath Hydroelectric Settlement Agreement ("KHSA"). Congress failed to pass legislation needed to implement the original KHSA. On April 6, 2016, PacifiCorp, the states of California and Oregon, and the United States Departments of the Interior and Commerce and other stakeholders executed an amendment to the KHSA. Consistent with the terms of the amended KHSA, on September 23, 2016, PacifiCorp and the Klamath River Renewal Corporation ("KRRC"), a private, independent nonprofit 501(c)(3) organization formed by signatories of the amended KSHA, jointly filed an application with the FERC to transfer the license for the four mainstem Klamath River hydroelectric generating facilities from PacifiCorp to the KRRC. Also on September 23, 2016, the KRRC filed an application with the FERC to surrender the license and decommission the facilities. The KRRC's license surrender application included a request for the FERC to refrain from acting on the surrender application until after the transfer of the license to the KRRC is effective. Under the amended KHSA, PacifiCorp and its customers are protected from uncapped dam removal costs and liabilities. The KRRC must indemnify PacifiCorp from liabilities associated with dam removal. The amended KHSA also limits PacifiCorp's contribution to facilities removal costs to no more than $200 million , of which up to $184 million would be collected from PacifiCorp's Oregon customers with the remainder to be collected from PacifiCorp's California customers. California voters approved a water bond measure in November 2014 from which the state of California's contribution towards facilities removal costs are being drawn. In accordance with this bond measure, additional funding of up to $250 million for facilities removal costs was included in the California state budget in 2016, with the funding effective for at least five years. If facilities removal costs exceed the combined funding that will be available from PacifiCorp's Oregon and California customers and the state of California, sufficient funds would need to be provided by the KRRC or an entity other than PacifiCorp for removal to proceed. If certain conditions in the amended KHSA are not satisfied and the license does not transfer to the KRRC, PacifiCorp will resume relicensing with the FERC. As of December 31, 2017 , PacifiCorp's assets included $55 million of costs associated with the Klamath hydroelectric system's mainstem dams and the associated relicensing and settlement costs, which are being depreciated and amortized in accordance with state regulatory approvals through either December 31, 2019, or December 31, 2022, depending upon the state jurisdiction. Hydroelectric Commitments Certain of PacifiCorp's hydroelectric licenses contain requirements for PacifiCorp to make certain capital and operating expenditures related to its hydroelectric facilities. PacifiCorp estimates it is obligated to make capital expenditures of approximately $239 million over the next 10 years related to these licenses. Guarantees The Company has entered into guarantees as part of the normal course of business and the sale of certain assets. These guarantees are not expected to have a material impact on the Company's consolidated financial results.
PacifiCorp [Member]
Contractual Obligation [Line Items]
Commitments and Contingencies	Commitments and Contingencies Legal Matters PacifiCorp is party to a variety of legal actions arising out of the normal course of business. Plaintiffs occasionally seek punitive or exemplary damages. PacifiCorp does not believe that such normal and routine litigation will have a material impact on its consolidated financial results. Environmental Laws and Regulations PacifiCorp is subject to federal, state and local laws and regulations regarding air and water quality, renewable portfolio standards, emissions performance standards, climate change, coal combustion byproduct disposal, hazardous and solid waste disposal, protected species and other environmental matters that have the potential to impact PacifiCorp's current and future operations. PacifiCorp believes it is in material compliance with all applicable laws and regulations. Hydroelectric Relicensing PacifiCorp's Klamath hydroelectric system is currently operating under annual licenses with the FERC. In February 2010, PacifiCorp, the United States Department of the Interior, the United States Department of Commerce, the state of California, the state of Oregon and various other governmental and non-governmental settlement parties signed the Klamath Hydroelectric Settlement Agreement ("KHSA"). Among other things, the KHSA provided that the United States Department of the Interior would conduct scientific and engineering studies to assess whether removal of the Klamath hydroelectric system's mainstem dams was in the public interest and would advance restoration of the Klamath Basin's salmonid fisheries. If it was determined that dam removal should proceed, dam removal would begin no earlier than 2020. Congress failed to pass legislation needed to implement the original KHSA. Hence, in February 2016, the principal parties to the KHSA (PacifiCorp, the states of California and Oregon and the United States Departments of the Interior and Commerce) executed an agreement in principle committing to explore potential amendment of the KHSA to facilitate removal of the Klamath dams through a FERC process without the need for federal legislation. On April 6, 2016, PacifiCorp, the states of California and Oregon, and the United States Departments of the Interior and Commerce and other stakeholders executed an amendment to the KHSA. Consistent with the terms of the amended KHSA, on September 23, 2016, PacifiCorp and the Klamath River Renewal Corporation ("KRRC"), a private, independent nonprofit 501(c)(3) organization formed by signatories of the amended KSHA, jointly filed an application with the FERC to transfer the license for the four mainstem Klamath River hydroelectric generating facilities from PacifiCorp to the KRRC. Also on September 23, 2016, the KRRC filed an application with the FERC to surrender the license and decommission the facilities. The KRRC's license surrender application included a request for the FERC to refrain from acting on the surrender application until after the transfer of the license to the KRRC is effective. Under the amended KHSA, PacifiCorp and its customers continue to be protected from uncapped dam removal costs and liabilities. The KRRC must indemnify PacifiCorp from liabilities associated with dam removal. The amended KHSA also limits PacifiCorp's contribution to facilities removal costs to no more than $200 million , of which up to $184 million would be collected from PacifiCorp's Oregon customers with the remainder to be collected from PacifiCorp's California customers. California voters approved a water bond measure in November 2014 from which the state of California's contribution towards facilities removal costs will be drawn. In accordance with this bond measure, additional funding of up to $250 million for facilities removal costs was included in the California state budget in 2016, with the funding effective for at least five years. If facilities removal costs exceed the combined funding that will be available from PacifiCorp's Oregon and California customers and the state of California, sufficient funds would need to be provided by the KRRC or an entity other than PacifiCorp in order for removal to proceed. If certain conditions in the amended KHSA are not satisfied and the license does not transfer to the KRRC, PacifiCorp will resume relicensing with the FERC. As of December 31, 2017 , PacifiCorp's assets included $55 million of costs associated with the Klamath hydroelectric system's mainstem dams and the associated relicensing and settlement costs, which are being depreciated and amortized in accordance with state regulatory approvals through either December 31, 2019, or December 31, 2022, depending upon the state jurisdiction. Hydroelectric Commitments Certain of PacifiCorp's hydroelectric licenses contain requirements for PacifiCorp to make certain capital and operating expenditures related to its hydroelectric facilities. PacifiCorp estimates it is obligated to make capital expenditures of approximately $239 million over the next 10 years related to these licenses. Commitments PacifiCorp has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31, 2017 are as follows (in millions): 2018 2019 2020 2021 2022 2023 and Thereafter Total Contract type: Purchased electricity contracts - commercially operable $ 276 $ 165 $ 161 $ 150 $ 145 $ 1,574 $ 2,471 Purchased electricity contracts - non-commercially operable 9 18 26 26 27 451 557 Fuel contracts 695 619 591 453 337 1,268 3,963 Construction commitments 85 29 3 — — — 117 Transmission 112 96 66 49 39 428 790 Operating leases and easements 7 7 7 7 6 97 131 Maintenance, service and other contracts 36 34 22 25 14 80 211 Total commitments $ 1,220 $ 968 $ 876 $ 710 $ 568 $ 3,898 $ 8,240 Purchased Electricity Contracts - Commercially Operable As part of its energy resource portfolio, PacifiCorp acquires a portion of its electricity through long-term purchases and exchange agreements. PacifiCorp has several power purchase agreements with wind-powered generating facilities that are not included in the table above as the payments are based on the amount of energy generated and there are no minimum payments. Included in the purchased electricity payments are any power purchase agreements that meet the definition of a lease. Rent expense related to those power purchase agreements that meet the definition of a lease totaled $14 million for 2017 and 2016 and $13 million for 2015 . Included in the minimum fixed annual payments for purchased electricity above are commitments to purchase electricity from several hydroelectric systems under long-term arrangements with public utility districts. These purchases are made on a "cost-of-service" basis for a stated percentage of system output and for a like percentage of system operating expenses and debt service. These costs are included in energy costs on the Consolidated Statements of Operations. PacifiCorp is required to pay its portion of operating costs and its portion of the debt service, whether or not any electricity is produced. These arrangements accounted for less than 5% of PacifiCorp's 2017 , 2016 and 2015 energy sources. Purchased Electricity Contracts - Non-commercially Operable PacifiCorp has several contracts for purchases of electricity from facilities that have not yet achieved commercial operation. To the extent any of these facilities do not achieve commercial operation, PacifiCorp has no obligation to the counterparty. Fuel Contracts PacifiCorp has "take or pay" coal and natural gas contracts that require minimum payments. Construction Commitments PacifiCorp's construction commitments included in the table above relate to firm commitments and include costs associated with certain generating plant, transmission, and distribution projects. Transmission PacifiCorp has contracts for the right to transmit electricity over other entities' transmission lines to facilitate delivery to PacifiCorp's customers. Operating Leases and Easements PacifiCorp has non-cancelable operating leases primarily for certain operating facilities, office space, land and equipment that expire at various dates through the year ending December 31, 2096. These leases generally require PacifiCorp to pay for insurance, taxes and maintenance applicable to the leased property. Certain leases contain renewal options for varying periods and escalation clauses for adjusting rent to reflect changes in price indices. PacifiCorp also has non-cancelable easements for land on which certain of its assets, primarily wind-powered generating facilities, are located. Rent expense totaled $15 million for the years ended December 31, 2017 , 2016 and 2015 . Guarantees PacifiCorp has entered into guarantees as part of the normal course of business and the sale of certain assets. These guarantees are not expected to have a material impact on PacifiCorp's consolidated financial results.
MidAmerican Energy Company [Member]
Contractual Obligation [Line Items]
Commitments and Contingencies	Commitments and Contingencies Commitments MidAmerican Energy had the following firm commitments that are not reflected on the Balance Sheet. Minimum payments as of December 31, 2017 , are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total Contract type: Coal and natural gas for generation $ 112 $ 56 $ 12 $ 9 $ 8 $ — $ 197 Electric capacity and transmission 34 31 31 27 16 43 182 Natural gas contracts for gas operations 122 75 73 57 42 42 411 Construction commitments 790 28 2 — — — 820 Easements and operating leases 22 21 21 21 21 713 819 Maintenance and services contracts 96 102 119 114 154 233 818 $ 1,176 $ 313 $ 258 $ 228 $ 241 $ 1,031 $ 3,247 Coal, Natural Gas, Electric Capacity and Transmission Commitments MidAmerican Energy has coal supply and related transportation and lime contracts for its coal-fueled generating facilities. MidAmerican Energy expects to supplement the coal contracts with additional contracts and spot market purchases to fulfill its future coal supply needs. Additionally, MidAmerican Energy has a natural gas transportation contract for a natural gas-fueled generating facility. The contracts have minimum payment commitments ranging through 2022 . MidAmerican Energy has various natural gas supply and transportation contracts for its regulated and nonregulated gas operations that have minimum payment commitments ranging through 2037 . MidAmerican Energy has contracts to purchase electric capacity that have minimum payment commitments ranging through 2028 . MidAmerican Energy also has contracts for the right to transmit electricity over other entities' transmission lines with minimum payment commitments ranging through 2022 . Construction Commitments MidAmerican Energy's firm construction commitments reflected in the table above consist primarily of contracts for the construction of wind-powered generating facilities in 2018, the settlement of asset retirement obligations for ash pond closures and the construction in 2018 of the last of four Multi-Value Projects approved by the Midcontinent Independent System Operator, Inc. for high voltage transmission lines in Iowa and Illinois. Easements and Operating Leases MidAmerican Energy has non-cancelable easements with minimum payment commitments ranging through 2061 for land in Iowa on which certain of its assets, primarily wind-powered generating facilities, are located. MidAmerican Energy also has non-cancelable operating leases with minimum payment commitments ranging through 2020 primarily for office and other building space, rail cars and computer equipment. These leases generally require MidAmerican Energy to pay for insurance, taxes and maintenance applicable to the leased property. Certain leases contain renewal options for varying periods and escalation clauses for adjusting rent to reflect changes in price indices. Rent expense on non-cancelable operating leases totaled $3 million , $4 million and $4 million for 2017 , 2016 and 2015 , respectively. Maintenance and Services Contracts MidAmerican Energy has non-cancelable maintenance and services contracts related to various generating facilities with minimum payment commitments ranging through 2027 . Environmental Laws and Regulations MidAmerican Energy is subject to federal, state and local laws and regulations regarding air and water quality, emissions performance standards, climate change, coal combustion byproduct disposal, hazardous and solid waste disposal, protected species and other environmental matters that have the potential to impact its current and future operations. MidAmerican Energy believes it is in material compliance with all applicable laws and regulations. Transmission Rates MidAmerican Energy's wholesale transmission rates are set annually using FERC-approved formula rates subject to true-up for actual cost of service. Prior to September 2016, the rates in effect were based on a 12.38% return on equity ("ROE"). In November 2013 and February 2015, a coalition of intervenors filed successive complaints with the FERC requesting that the 12.38% ROE no longer be found just and reasonable and sought to reduce the base ROE to 9.15% and 8.67% , respectively. MidAmerican Energy is authorized by the FERC to include a 0.50% adder beyond the base ROE effective January 2015. In September 2016, the FERC issued an order for the first complaint, which reduces the base ROE to 10.32% and requires refunds, plus interest, for the period from November 2013 through February 2015. It is uncertain when the FERC will rule on the second complaint, covering the period from February 2015 through May 2016. MidAmerican Energy believes it is probable that the FERC will order a base ROE lower than 12.38% in the second complaint and, as of December 31, 2017, has accrued a $9 million liability for refunds of amounts collected under the higher ROE from November 2013 through May 2016. Legal Matters MidAmerican Energy is party to a variety of legal actions arising out of the normal course of business. Plaintiffs occasionally seek punitive or exemplary damages. MidAmerican Energy does not believe that such normal and routine litigation will have a material impact on its financial results.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Contractual Obligation [Line Items]
Commitments and Contingencies	Commitments and Contingencies Refer to Note 15 of MidAmerican Energy's Notes to Financial Statements. Legal Matters MidAmerican Funding is party to a variety of legal actions arising out of the normal course of business. Plaintiffs occasionally seek punitive or exemplary damages. MidAmerican Funding does not believe that such normal and routine litigation will have a material impact on its consolidated financial results.
Nevada Power Company [Member]
Contractual Obligation [Line Items]
Commitments and Contingencies	Commitments and Contingencies Environmental Laws and Regulations Nevada Power is subject to federal, state and local laws and regulations regarding air and water quality, renewable portfolio standards, emissions performance standards, climate change, coal combustion byproduct disposal, hazardous and solid waste disposal, protected species and other environmental matters that have the potential to impact Nevada Power 's current and future operations. Nevada Power believes it is in material compliance with all applicable laws and regulations. Senate Bill 123 In June 2013, the Nevada State Legislature passed Senate Bill No. 123 ("SB 123"), which included the retirement of coal plants and replacing the capacity with renewable facilities and other generating facilities. In May 2014, Nevada Power filed its ERCR Plan in compliance with SB 123. In July 2015, Nevada Power filed an amendment to its ERCR Plan with the PUCN which was approved in September 2015. In June 2015, the Nevada State Legislature passed Assembly Bill No. 498, which modified the capacity replacement components of SB 123. Consistent with the ERCR Plan, Nevada Power acquired a 272 -MW natural gas co-generating facility in 2014, acquired a 210 -MW natural gas peaking facility in 2014, constructed a 15 -MW solar photovoltaic facility in 2015, contracted two renewable power purchase agreements with 100 -MW solar photovoltaic generating facilities in 2015, contracted a renewable power purchase agreement with 100 -MW solar photovoltaic generating facility in 2016 and acquired the remaining 130 MW, 25% , of the Silverhawk natural gas-fueled generating facility in April 2017, of which 54 MW were approved as part of the ERCR Plan. Nevada Power has the option to acquire 35 MW of nameplate renewable energy capacity in the future under the ERCR Plan, subject to PUCN approval. Nevada Power retired Reid Gardner Units 1, 2, and 3, 300 MW of coal-fueled generation, in 2014 and Reid Gardner Unit 4, 257 MW of coal-fueled generation, in March 2017. These transactions are related to Nevada Power's compliance with SB 123, resulting in the retirement of 812 MW of coal-fueled generation by 2019. Legal Matters Nevada Power is party to a variety of legal actions arising out of the normal course of business. Plaintiffs occasionally seek punitive or exemplary damages. Nevada Power does not believe that such normal and routine litigation will have a material impact on its consolidated financial results. Nevada Power is also involved in other kinds of legal actions, some of which assert or may assert claims or seek to impose fines, penalties and other costs in substantial amounts and are described below. Commitments Nevada Power has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31 , 2017 are as follows (in millions): 2018 2019 2020 2021 2022 2023 and Thereafter Total Contract type: Fuel, capacity and transmission contract commitments $ 591 $ 450 $ 377 $ 378 $ 380 $ 5,208 $ 7,384 Fuel and capacity contract commitments (not commercially operable) — 15 22 24 25 421 507 Operating leases and easements 7 7 8 8 7 54 91 Maintenance, service and other contracts 46 44 43 39 37 40 249 Total commitments $ 644 $ 516 $ 450 $ 449 $ 449 $ 5,723 $ 8,231 Fuel and Capacity Contract Commitments Purchased Power Nevada Power has several contracts for long-term purchase of electric energy which have been approved by the PUCN. The expiration of these contracts range from 2018 to 2067 . Purchased power includes contracts which meet the definition of a lease. Nevada Power 's operations and maintenance expense for purchase power contracts which met the lease criteria for 2017 , 2016 and 2015 were $310 million , $302 million and $264 million , respectively, and are recorded as cost of fuel, energy and capacity on the Consolidated Statements of Operations. Coal and Natural Gas Nevada Power has a contract for the transportation of coal that extends through 2018 . Additionally, gas transportation contracts expire from 2022 to 2032 and the gas supply contract expires from 2018 to 2019 . Fuel and Capacity Contract Commitments - Not Commercially Operable Nevada Power has several contracts for long-term purchase of electric energy in which the facility remains under development. Amounts represent the estimated payments under renewable energy power purchase contracts, which have been approved by the PUCN and are contingent upon the developers obtaining commercial operation and their ability to deliver power. Operating Leases and Easements Nevada Power has non-cancelable operating leases primarily for office equipment, office space, certain operating facilities, vehicles and land. These leases generally require Nevada Power to pay for insurance, taxes and maintenance applicable to the leased property. Certain leases contain renewal options for varying periods and escalation clauses for adjusting rent to reflect changes in price indices. Nevada Power also has non-cancelable easements for land. Operations and maintenance expense on non-cancelable operating leases and easements totaled $9 million , $13 million and $11 million for the years ended December 31 , 2017 , 2016 and 2015 , respectively. Maintenance, Service and Other Contracts Nevada Power has long-term service agreements for the performance of maintenance on generation units. Obligation amounts are based on estimated usage. The estimated expiration of these service agreements range from 2019 to 2026 .
Sierra Pacific Power Company [Member]
Contractual Obligation [Line Items]
Commitments and Contingencies	Commitments and Contingencies Environmental Laws and Regulations Sierra Pacific is subject to federal, state and local laws and regulations regarding air and water quality, renewable portfolio standards, emissions performance standards, climate change, coal combustion byproduct disposal, hazardous and solid waste disposal, protected species and other environmental matters that have the potential to impact Sierra Pacific 's current and future operations. Sierra Pacific believes it is in material compliance with all applicable laws and regulations. Legal Matters Sierra Pacific is party to a variety of legal actions arising out of the normal course of business. Plaintiffs occasionally seek punitive or exemplary damages. Sierra Pacific does not believe that such normal and routine litigation will have a material impact on its consolidated financial results. Commitments Sierra Pacific has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31 , 2017 are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total Contract type: Fuel, capacity and transmission contract commitments $ 200 $ 155 $ 114 $ 74 $ 71 $ 515 $ 1,129 Fuel and capacity contract commitments (not commercially operable) — 7 17 22 22 590 658 Operating leases and easements 4 4 4 3 2 54 71 Maintenance, service and other contracts 6 6 6 7 5 12 42 Total commitments $ 210 $ 172 $ 141 $ 106 $ 100 $ 1,171 $ 1,900 Fuel and Capacity Contract Commitments Purchased Power Sierra Pacific has several contracts for long-term purchase of electric energy which have been approved by the PUCN. The expiration of these contracts range from 2018 to 2045 . Purchased power includes contracts which meet the definition of a lease. Sierra Pacific 's operating and maintenance expense for purchase power contracts which met the lease criteria for 2017 , 2016 and 2015 were $74 million , $69 million and $65 million , respectively, and are recorded as cost of fuel, energy and capacity on the Consolidated Statements of Operations. Coal and Natural Gas Sierra Pacific has a long-term contract for the transport of coal that expires in 2018 . Additionally, gas transportation contracts expire from 2019 to 2046 and the gas supply contracts expire from 2018 to 2019 . Operating Leases and Easements Sierra Pacific has non-cancelable operating leases primarily for office equipment, office space, certain operating facilities, vehicles and land. These leases generally require Sierra Pacific to pay for insurance, taxes and maintenance applicable to the leased property. Certain leases contain renewal options for varying periods and escalation clauses for adjusting rent to reflect changes in price indices. Sierra Pacific also has non-cancelable easements for land. Operating and maintenance expense on non-cancelable operating leases and easements totaled $4 million , $6 million and $7 million for the year-ended December 31 , 2017 , 2016 and 2015 , respectively. Maintenance, Service and Other Contracts Sierra Pacific has long-term service agreements for the performance of maintenance on generation units. Obligation amounts are based on estimated usage. The estimated expiration of these service agreements range from 2019 to 2039 .

Preferred Stock (Notes)

Preferred Stock (Notes)	12 Months Ended
	Dec. 31, 2017
PacifiCorp [Member]
Class of Stock [Line Items]
Preferred Stock [Text Block]	Preferred Stock PacifiCorp has 3,500 thousand shares of Serial Preferred Stock authorized at the stated value of $100 per share. PacifiCorp had 24 thousand shares of Serial Preferred Stock issued and outstanding as of December 31, 2017 and 2016 . The outstanding preferred stock series are non-redeemable and have annual dividend rates of 6.00% and 7.00% . In the event of voluntary liquidation, all preferred stock is entitled to stated value or a specified preference amount per share plus accrued dividends. Upon involuntary liquidation, all preferred stock is entitled to stated value plus accrued dividends. Dividends on all preferred stock are cumulative. Holders also have the right to elect members to the PacifiCorp Board of Directors in the event dividends payable are in default in an amount equal to four full quarterly payments. PacifiCorp also has 16 million shares of No Par Serial Preferred Stock and 127 thousand shares of 5% Preferred Stock authorized, but no shares were issued or outstanding as of December 31, 2017 and 2016 .

BHE Shareholders' Equity (Notes

BHE Shareholders' Equity (Notes)	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
BHE Shareholders' Equity [Text Block]	BHE Shareholders' Equity Common Stock On March 14, 2000, and as amended on December 7, 2005, BHE 's shareholders entered into a Shareholder Agreement that provides specific rights to certain shareholders. One of these rights allows certain shareholders the ability to put their common shares back to BHE at the then current fair value dependent on certain circumstances controlled by BHE . On June 19, 2017, BHE issued $100 million of its 5.00% junior subordinated debentures due June 2057 in exchange for 181,819 shares of its common stock from certain family interests of Mr. Walter Scott, Jr. On February 17, 2017, BHE repurchased from certain family interests of Mr. Walter Scott, Jr. 35,000 shares of its common stock for $19 million . On February 17, 2015, BHE repurchased from certain family interests of Mr. Walter Scott, Jr. 75,000 shares of its common stock for $36 million . Restricted Net Assets BHE has maximum debt-to-total capitalization percentage restrictions imposed by its senior unsecured credit facilities expiring in May 2018 and June 2020 which, in certain circumstances, limit BHE 's ability to make cash dividends or distributions. As a result of this restriction, BHE has restricted net assets of $16.9 billion as of December 31, 2017 . Certain of BHE 's subsidiaries have restrictions on their ability to dividend, loan or advance funds to BHE due to specific legal or regulatory restrictions, including, but not limited to, maximum debt-to-total capitalization percentages and commitments made to state commissions or federal agencies in connection with past acquisitions. As a result of these restrictions, BHE 's subsidiaries had restricted net assets of $19.4 billion as of December 31, 2017 .

Common Shareholder's Equity Com

Common Shareholder's Equity Common Shareholder's Equity (Notes)	12 Months Ended
	Dec. 31, 2017
Class of Stock [Line Items]
Common Shareholder's Equity [Text Block]	BHE Shareholders' Equity Common Stock On March 14, 2000, and as amended on December 7, 2005, BHE 's shareholders entered into a Shareholder Agreement that provides specific rights to certain shareholders. One of these rights allows certain shareholders the ability to put their common shares back to BHE at the then current fair value dependent on certain circumstances controlled by BHE . On June 19, 2017, BHE issued $100 million of its 5.00% junior subordinated debentures due June 2057 in exchange for 181,819 shares of its common stock from certain family interests of Mr. Walter Scott, Jr. On February 17, 2017, BHE repurchased from certain family interests of Mr. Walter Scott, Jr. 35,000 shares of its common stock for $19 million . On February 17, 2015, BHE repurchased from certain family interests of Mr. Walter Scott, Jr. 75,000 shares of its common stock for $36 million . Restricted Net Assets BHE has maximum debt-to-total capitalization percentage restrictions imposed by its senior unsecured credit facilities expiring in May 2018 and June 2020 which, in certain circumstances, limit BHE 's ability to make cash dividends or distributions. As a result of this restriction, BHE has restricted net assets of $16.9 billion as of December 31, 2017 . Certain of BHE 's subsidiaries have restrictions on their ability to dividend, loan or advance funds to BHE due to specific legal or regulatory restrictions, including, but not limited to, maximum debt-to-total capitalization percentages and commitments made to state commissions or federal agencies in connection with past acquisitions. As a result of these restrictions, BHE 's subsidiaries had restricted net assets of $19.4 billion as of December 31, 2017 .
PacifiCorp [Member]
Class of Stock [Line Items]
Common Shareholder's Equity [Text Block]	Common Shareholder's Equity In February 2018, PacifiCorp declared a dividend of $250 million payable to PPW Holdings LLC, a wholly owned subsidiary of BHE and PacifiCorp's direct parent company ("PPW Holdings") in March 2018. Through PPW Holdings, BHE is the sole shareholder of PacifiCorp's common stock. The state regulatory orders that authorized BHE's acquisition of PacifiCorp contain restrictions on PacifiCorp's ability to pay dividends to the extent that they would reduce PacifiCorp's common equity below specified percentages of defined capitalization. As of December 31, 2017 , the most restrictive of these commitments prohibits PacifiCorp from making any distribution to PPW Holdings or BHE without prior state regulatory approval to the extent that it would reduce PacifiCorp's common equity below 44% of its total capitalization, excluding short-term debt and current maturities of long-term debt. The terms of this commitment treat 50% of PacifiCorp's remaining balance of preferred stock in existence prior to the acquisition of PacifiCorp by BHE as common equity. As of December 31, 2017 , PacifiCorp's actual common equity percentage, as calculated under this measure, was 54% , and PacifiCorp would have been permitted to dividend $2.5 billion under this commitment. These commitments also restrict PacifiCorp from making any distributions to either PPW Holdings or BHE if PacifiCorp's senior unsecured debt rating is BBB- or lower by Standard & Poor's Rating Services or Fitch Ratings or Baa3 or lower by Moody's Investor Service, as indicated by two of the three rating services. As of December 31, 2017 , PacifiCorp met the minimum required senior unsecured debt ratings for making distributions. PacifiCorp is also subject to a maximum debt-to-total capitalization percentage under various financing agreements as further discussed in Note 6 .

Components of Accumulated Other

Components of Accumulated Other Comprehensive Loss, Net (Notes)	12 Months Ended
	Dec. 31, 2017
Schedule of accumulated other comprehensive income (loss)
Comprehensive Income (Loss)	Components of Accumulated Other Comprehensive Loss, Net The following table shows the change in accumulated other comprehensive loss attributable to BHE shareholders by each component of other comprehensive income (loss), net of applicable income taxes, for the year ended December 31 (in millions): Accumulated Unrealized Other Unrecognized Foreign Gains on Unrealized Comprehensive Amounts on Currency Available- Gains on Loss Attributable Retirement Translation For-Sale Cash Flow To BHE Benefits Adjustment Securities Hedges Shareholders, Net Balance, December 31, 2014 $ (490 ) $ (412 ) $ 390 $ 18 $ (494 ) Other comprehensive income (loss) 52 (680 ) 225 (11 ) (414 ) Balance, December 31, 2015 (438 ) (1,092 ) 615 7 (908 ) Other comprehensive income (loss) (9 ) (583 ) (30 ) 19 (603 ) Balance, December 31, 2016 (447 ) (1,675 ) 585 26 (1,511 ) Other comprehensive income (loss) 64 546 500 3 1,113 Balance, December 31, 2017 $ (383 ) $ (1,129 ) $ 1,085 $ 29 $ (398 ) Reclassifications from AOCI to net income for the years ended December 31, 2017 , 2016 and 2015 were insignificant. For information regarding cash flow hedge reclassifications from AOCI to net income in their entirety, refer to Note 14 . Additionally, refer to the "Foreign Operations" discussion in Note 12 for information about unrecognized amounts on retirement benefits reclassifications from AOCI that do not impact net income in their entirety.
PacifiCorp [Member]
Schedule of accumulated other comprehensive income (loss)
Comprehensive Income (Loss)	Components of Accumulated Other Comprehensive Loss, Net Accumulated other comprehensive loss, net consists of unrecognized amounts on retirement benefits, net of tax, of $15 million and $12 million as of December 31, 2017 and 2016 , respectively.
MidAmerican Energy Company [Member]
Schedule of accumulated other comprehensive income (loss)
Comprehensive Income (Loss)	Components of Accumulated Other Comprehensive Loss, Net The following table shows the change in accumulated other comprehensive loss by each component of other comprehensive income, net of applicable income taxes, for the year ended December 31, 2016 (in millions): Unrealized Unrealized Accumulated Losses on Losses Other Available-For-Sale on Cash Flow Comprehensive Securities Hedges Loss, Net Balance, December 31, 2015 $ (3 ) $ (27 ) $ (30 ) Other comprehensive income 3 — 3 Dividend (Note 3) — 27 27 Balance, December 31, 2016 $ — $ — $ — For information regarding cash flow hedge reclassifications from AOCI to net income in their entirety for the years ended December 31, 2016 and 2015 , refer to Note 13 .
MidAmerican Funding, LLC and Subsidiaries [Domain]
Schedule of accumulated other comprehensive income (loss)
Comprehensive Income (Loss)	Components of Accumulated Other Comprehensive Loss, Net Refer to Note 16 of MidAmerican Energy's Notes to Financial Statements.

Variable-Interest Entities Vari

Variable-Interest Entities Variable-Interest Entities (Notes)	12 Months Ended
	Dec. 31, 2017
PacifiCorp [Member]
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity Disclosure [Text Block]	Variable-Interest Entities PacifiCorp holds a two-thirds interest in Bridger Coal Company ("Bridger Coal"), which supplies coal to the Jim Bridger generating facility that is owned two-thirds by PacifiCorp and one-third by PacifiCorp's joint venture partner in Bridger Coal. PacifiCorp purchases two-thirds of the coal produced by Bridger Coal, while the remaining coal is purchased by the joint venture partner. The power to direct the activities that most significantly impact Bridger Coal's economic performance are shared with the joint venture partner. Each joint venture partner is jointly and severally liable for the obligations of Bridger Coal. Bridger Coal's necessary working capital to carry out its mining operations is financed by contributions from PacifiCorp and its joint venture partner. PacifiCorp's equity investment in Bridger Coal was $137 million and $165 million as of December 31, 2017 and 2016 , respectively. Refer to Note 18 for information regarding related-party transactions with Bridger Coal.

Noncontrolling Interests (Notes

Noncontrolling Interests (Notes)	12 Months Ended
	Dec. 31, 2017
Noncontrolling Interest [Line Items]
Noncontrolling Interests [Text Block]	Noncontrolling Interests Included in noncontrolling interests on the Consolidated Balance Sheets are preferred securities of subsidiaries of $58 million as of December 31, 2017 and 2016 , consisting of $56 million of 8.061% cumulative preferred securities of Northern Electric plc., a subsidiary of Northern Powergrid , which are redeemable in the event of the revocation of Northern Electric plc.'s electricity distribution license by the Secretary of State, and $2 million of nonredeemable preferred stock of PacifiCorp.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Noncontrolling Interest [Line Items]
Other, Net [Text Block]	Other Income and (Expense) - Other, Net Other, net, as shown on the Consolidated Statements of Operations, includes the following other income (expense) items for the years ended December 31 (in millions): 2017 2016 2015 Corporate-owned life insurance income $ 13 $ 8 $ 4 Gain on redemption of auction rate securities — 5 — Gains on sales of assets and other investments 1 3 13 Loss on debt tender offer (29 ) — — Interest income and other, net 6 3 2 Total $ (9 ) $ 19 $ 19 Refer to Note 9 for information regarding the debt tender offer. MidAmerican Funding recognized a $13 million pre-tax gain on the sale of an investment in a generating facility lease in 2015.

Segment Information (Notes)

Segment Information (Notes)	12 Months Ended
	Dec. 31, 2017
Segment Reporting Information [Line Items]
Segment Information [Text Block]	Segment Information The Company's reportable segments with foreign operations include Northern Powergrid , whose business is principally in the United Kingdom, BHE Transmission , whose business includes operations in Canada, and BHE Renewables , whose business includes operations in the Philippines. Intersegment eliminations and adjustments, including the allocation of goodwill, have been made. Information related to the Company's reportable segments is shown below (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: PacifiCorp $ 5,237 $ 5,201 $ 5,232 MidAmerican Funding 2,846 2,631 2,515 NV Energy 3,015 2,895 3,351 Northern Powergrid 949 995 1,140 BHE Pipeline Group 993 978 1,016 BHE Transmission 699 502 592 BHE Renewables 838 743 728 HomeServices 3,443 2,801 2,526 BHE and Other (1) 594 676 780 Total operating revenue $ 18,614 $ 17,422 $ 17,880 Depreciation and amortization: PacifiCorp $ 796 $ 783 $ 780 MidAmerican Funding 500 479 407 NV Energy 422 421 410 Northern Powergrid 214 200 202 BHE Pipeline Group 159 206 204 BHE Transmission 239 241 185 BHE Renewables 251 230 216 HomeServices 66 31 29 BHE and Other (1) (1 ) — (5 ) Total depreciation and amortization $ 2,646 $ 2,591 $ 2,428 Operating income: PacifiCorp $ 1,462 $ 1,427 $ 1,344 MidAmerican Funding 562 566 451 NV Energy 765 770 812 Northern Powergrid 436 494 593 BHE Pipeline Group 475 455 464 BHE Transmission 322 92 260 BHE Renewables 316 256 255 HomeServices 214 212 184 BHE and Other (1) (38 ) (21 ) (35 ) Total operating income 4,514 4,251 4,328 Interest expense (1,841 ) (1,854 ) (1,904 ) Capitalized interest 45 139 74 Allowance for equity funds 76 158 91 Interest and dividend income 111 120 107 Other, net (398 ) 36 39 Total income before income tax (benefit) expense and equity (loss) income $ 2,507 $ 2,850 $ 2,735 Years Ended December 31, 2017 2016 2015 Interest expense: PacifiCorp $ 381 $ 381 $ 383 MidAmerican Funding 237 218 206 NV Energy 233 250 262 Northern Powergrid 133 136 145 BHE Pipeline Group 43 50 66 BHE Transmission 169 153 146 BHE Renewables 204 198 193 HomeServices 7 2 3 BHE and Other (1) 434 466 500 Total interest expense $ 1,841 $ 1,854 $ 1,904 Income tax (benefit) expense: PacifiCorp $ 362 $ 341 $ 328 MidAmerican Funding (202 ) (139 ) (150 ) NV Energy 221 200 207 Northern Powergrid 57 22 35 BHE Pipeline Group 170 163 158 BHE Transmission (124 ) 26 63 BHE Renewables (2) (795 ) (32 ) 41 HomeServices 49 81 72 BHE and Other (1) (292 ) (259 ) (304 ) Total income tax (benefit) expense $ (554 ) $ 403 $ 450 Capital expenditures: PacifiCorp $ 769 $ 903 $ 916 MidAmerican Funding 1,776 1,637 1,448 NV Energy 456 529 571 Northern Powergrid 579 579 674 BHE Pipeline Group 286 226 240 BHE Transmission 334 466 966 BHE Renewables 323 719 1,034 HomeServices 37 20 16 BHE and Other 11 11 10 Total capital expenditures $ 4,571 $ 5,090 $ 5,875 As of December 31, 2017 2016 2015 Property, plant and equipment, net: PacifiCorp $ 19,203 $ 19,162 $ 19,039 MidAmerican Funding 14,221 12,835 11,737 NV Energy 9,770 9,825 9,767 Northern Powergrid 6,075 5,148 5,790 BHE Pipeline Group 4,587 4,423 4,345 BHE Transmission 6,330 5,810 5,301 BHE Renewables 5,637 5,302 4,805 HomeServices 117 78 70 BHE and Other (69 ) (74 ) (85 ) Total property, plant and equipment, net $ 65,871 $ 62,509 $ 60,769 Total assets: PacifiCorp $ 23,086 $ 23,563 $ 23,550 MidAmerican Funding 18,444 17,571 16,315 NV Energy 13,903 14,320 14,656 Northern Powergrid 7,565 6,433 7,317 BHE Pipeline Group 5,134 5,144 4,953 BHE Transmission 9,009 8,378 7,553 BHE Renewables 7,687 7,010 5,892 HomeServices 2,722 1,776 1,705 BHE and Other 2,658 1,245 1,677 Total assets $ 90,208 $ 85,440 $ 83,618 Years Ended December 31, 2017 2016 2015 Operating revenue by country: United States $ 16,916 $ 15,895 $ 16,121 United Kingdom 948 995 1,140 Canada 699 506 600 Philippines and other 51 26 19 Total operating revenue by country $ 18,614 $ 17,422 $ 17,880 Income before income tax (benefit) expense and equity (loss) income by country: United States $ 1,927 $ 2,264 $ 2,034 United Kingdom 313 382 472 Canada 167 135 165 Philippines and other 100 69 64 Total income before income tax (benefit) expense and equity (loss) income by country: $ 2,507 $ 2,850 $ 2,735 As of December 31, 2017 2016 2015 Property, plant and equipment, net by country: United States $ 53,579 $ 51,671 $ 49,680 United Kingdom 5,953 5,020 5,757 Canada 6,323 5,803 5,298 Philippines and other 16 15 34 Total property, plant and equipment, net by country $ 65,871 $ 62,509 $ 60,769 (1) The differences between the reportable segment amounts and the consolidated amounts, described as BHE and Other , relate to other corporate entities, including MidAmerican Energy Services, LLC, corporate functions and intersegment eliminations. (2) Income tax (benefit) expense includes the tax attributes of disregarded entities that are not required to pay income taxes and the earnings of which are taxable directly to BHE. The following table shows the change in the carrying amount of goodwill by reportable segment for the years ended December 31, 2017 and 2016 (in millions): BHE BHE MidAmerican NV Northern Pipeline BHE BHE Home- and PacifiCorp Funding Energy Powergrid Group Transmission Renewables Services Other Total December 31, 2015 $ 1,129 $ 2,102 $ 2,369 $ 1,056 $ 101 $ 1,428 $ 95 $ 794 $ 2 $ 9,076 Acquisitions — — — — — 4 — 46 — 50 Foreign currency translation — — — (126 ) — 42 — — (2 ) (86 ) Other — — — — (26 ) (4 ) — — — (30 ) December 31, 2016 1,129 2,102 2,369 930 75 1,470 95 840 — 9,010 Acquisitions — — — — — — — 508 — 508 Foreign currency translation — — — 61 — 101 — — — 162 Other — — — — (2 ) — — — — (2 ) December 31, 2017 $ 1,129 $ 2,102 $ 2,369 $ 991 $ 73 $ 1,571 $ 95 $ 1,348 $ — $ 9,678
MidAmerican Energy Company [Member]
Segment Reporting Information [Line Items]
Segment Information [Text Block]	Segment Information MidAmerican Energy has identified two reportable operating segments: regulated electric and regulated gas. The previously reported nonregulated energy segment consisted substantially of MidAmerican Energy's unregulated retail services business, which was transferred to a subsidiary of BHE and is excluded from the information below related to the statements of operations for all periods presented. The regulated electric segment derives most of its revenue from regulated retail sales of electricity to residential, commercial, and industrial customers and from wholesale sales. The regulated gas segment derives most of its revenue from regulated retail sales of natural gas to residential, commercial, and industrial customers and also obtains revenue by transporting gas owned by others through its distribution system. Pricing for regulated electric and regulated gas sales are established separately by regulatory agencies; therefore, management also reviews each segment separately to make decisions regarding allocation of resources and in evaluating performance. Common operating costs, interest income, interest expense and income tax expense are allocated to each segment based on certain factors, which primarily relate to the nature of the cost. Refer to Note 10 for a discussion of items affecting income tax (benefit) expense for the regulated electric and gas operating segments. The following tables provide information on a reportable segment basis (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: Regulated electric $ 2,108 $ 1,985 $ 1,837 Regulated gas 719 637 661 Other 10 3 4 Total operating revenue $ 2,837 $ 2,625 $ 2,502 Depreciation and amortization: Regulated electric $ 458 $ 436 $ 366 Regulated gas 42 43 41 Total depreciation and amortization $ 500 $ 479 $ 407 Operating income: Regulated electric $ 485 $ 497 $ 385 Regulated gas 77 68 64 Other (1 ) — — Total operating income $ 561 $ 565 $ 449 Interest expense: Regulated electric $ 196 $ 178 $ 166 Regulated gas 18 18 17 Total interest expense $ 214 $ 196 $ 183 Income tax (benefit) expense from continuing operations: Regulated electric $ (212 ) $ (156 ) $ (163 ) Regulated gas 29 22 16 Other — 2 — Total income tax (benefit) expense from continuing operations $ (183 ) $ (132 ) $ (147 ) Net income: Regulated electric $ 570 $ 512 $ 413 Regulated gas 35 32 33 Other — (2 ) — Income from continuing operations 605 542 446 Income on discontinued operations — — 16 Net income $ 605 $ 542 $ 462 Years Ended December 31, 2017 2016 2015 Utility construction expenditures: Regulated electric $ 1,686 $ 1,564 $ 1,365 Regulated gas 87 72 81 Total utility construction expenditures $ 1,773 $ 1,636 $ 1,446 As of December 31, 2017 2016 2015 Total assets: Regulated electric $ 14,914 $ 14,113 $ 12,970 Regulated gas 1,403 1,345 1,251 Other 1 1 164 Total assets $ 16,318 $ 15,459 $ 14,385
MidAmerican Funding, LLC and Subsidiaries [Domain]
Segment Reporting Information [Line Items]
Segment Information [Text Block]	Segment Information MidAmerican Funding has identified two reportable operating segments: regulated electric and regulated gas. The previously reported nonregulated energy segment consisted substantially of MidAmerican Energy's unregulated retail services business, which was transferred to a subsidiary of BHE and is excluded from the information below related to the statements of operations for all periods presented. The regulated electric segment derives most of its revenue from regulated retail sales of electricity to residential, commercial, and industrial customers and from wholesale sales. The regulated gas segment derives most of its revenue from regulated retail sales of natural gas to residential, commercial, and industrial customers and also obtains revenue by transporting gas owned by others through its distribution system. Pricing for regulated electric and regulated gas sales are established separately by regulatory agencies; therefore, management also reviews each segment separately to make decisions regarding allocation of resources and in evaluating performance. Common operating costs, interest income, interest expense and income tax expense are allocated to each segment based on certain factors, which primarily relate to the nature of the cost. "Other" in the tables below consists of the nonregulated subsidiaries of MidAmerican Funding not engaged in the energy business and parent company interest expense. Refer to Note 10 for a discussion of items affecting income tax (benefit) expense for the regulated electric and gas operating segments. The following tables provide information on a reportable segment basis (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: Regulated electric $ 2,108 $ 1,985 $ 1,837 Regulated gas 719 637 661 Other 19 9 17 Total operating revenue $ 2,846 $ 2,631 $ 2,515 Depreciation and amortization: Regulated electric $ 458 $ 436 $ 366 Regulated gas 42 43 41 Total depreciation and amortization $ 500 $ 479 $ 407 Operating income: Regulated electric $ 485 $ 497 $ 385 Regulated gas 77 68 64 Other — 1 2 Total operating income $ 562 $ 566 $ 451 Interest expense: Regulated electric $ 196 $ 178 $ 166 Regulated gas 18 18 17 Other 23 23 23 Total interest expense $ 237 $ 219 $ 206 Income tax (benefit) expense from continuing operations: Regulated electric $ (212 ) $ (156 ) $ (163 ) Regulated gas 29 22 16 Other (19 ) (5 ) (3 ) Total income tax (benefit) expense from continuing operations $ (202 ) $ (139 ) $ (150 ) Net income: Regulated electric $ 570 $ 512 $ 413 Regulated gas 35 32 33 Other (31 ) (12 ) (4 ) Income from continuing operations 574 532 442 Income on discontinued operations — — 16 Net income $ 574 $ 532 $ 458 Utility construction expenditures: Regulated electric $ 1,686 $ 1,564 $ 1,365 Regulated gas 87 72 81 Total utility construction expenditures $ 1,773 $ 1,636 $ 1,446 As of December 31, 2017 2016 2015 Total assets: Regulated electric $ 16,105 $ 15,304 $ 14,161 Regulated gas 1,482 1,424 1,330 Other 34 19 183 Total assets $ 17,621 $ 16,747 $ 15,674 Goodwill by reportable segment as of December 31, 2017 and 2016 , was as follows (in millions): Regulated electric $ 1,191 Regulated gas 79 Total $ 1,270
Sierra Pacific Power Company [Member]
Segment Reporting Information [Line Items]
Segment Information [Text Block]	Segment Information Sierra Pacific has identified two reportable operating segments: regulated electric and regulated natural gas. The regulated electric segment derives most of its revenue from regulated retail sales of electricity to residential, commercial, and industrial customers and from wholesale sales. The regulated natural gas segment derives most of its revenue from regulated retail sales of natural gas to residential, commercial, and industrial customers and also obtains revenue by transporting natural gas owned by others through its distribution system. Pricing for regulated electric and regulated natural gas sales are established separately by the PUCN; therefore, management also reviews each segment separately to make decisions regarding allocation of resources and in evaluating performance. Sierra Pacific believes presenting gross margin allows the reader to assess the impact of Sierra Pacific 's regulatory treatment and its overall regulatory environment on a consistent basis and is meaningful. Gross margin is calculated as operating revenue less cost of fuel, energy and capacity and natural gas purchased for resale ("cost of sales"). The following tables provide information on a reportable segment basis for the years ended December 31 (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: Regulated electric $ 713 $ 702 $ 810 Regulated gas 99 110 137 Total operating revenue $ 812 $ 812 $ 947 Cost of sales: Regulated electric $ 268 $ 265 $ 374 Regulated gas 42 55 84 Total cost of sales $ 310 $ 320 $ 458 Gross margin: Regulated electric $ 445 $ 437 $ 436 Regulated gas 57 55 53 Total gross margin $ 502 $ 492 $ 489 Operating and maintenance: Regulated electric $ 148 $ 153 $ 149 Regulated gas 18 17 18 Total operating and maintenance $ 166 $ 170 $ 167 Depreciation and amortization: Regulated electric $ 100 $ 101 $ 96 Regulated gas 14 17 17 Total depreciation and amortization $ 114 $ 118 $ 113 Operating income: Regulated electric $ 176 $ 161 $ 168 Regulated gas 22 19 16 Total operating income $ 198 $ 180 $ 184 Interest expense: Regulated electric $ 39 $ 49 $ 56 Regulated gas 4 5 5 Total interest expense $ 43 $ 54 $ 61 Income tax expense: Regulated electric $ 48 $ 44 $ 43 Regulated gas 7 5 4 Total income tax expense $ 55 $ 49 $ 47 Years Ended December 31, 2017 2016 2015 Capital expenditures: Regulated electric $ 169 $ 176 $ 229 Regulated gas 17 18 23 Total capital expenditures $ 186 $ 194 $ 252 As of December 31, Total assets: 2017 2016 2015 Regulated electric $ 3,103 $ 3,119 $ 3,060 Regulated gas 300 314 316 Regulated common assets (1) 10 60 111 Total assets $ 3,413 $ 3,493 $ 3,487 (1) Consists principally of cash and cash equivalents not included in either the regulated electric or regulated natural gas segments.

Unaudited Quarterly Operating R

Unaudited Quarterly Operating Results Unaudited Quarterly Operating Results (Notes)	12 Months Ended
	Dec. 31, 2017
MidAmerican Energy Company [Member]
Quarterly Operating Results [Line Items]
Quarterly Financial Information [Text Block]	Unaudited Quarterly Operating Results 2017 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 695 $ 658 $ 813 $ 671 Operating income 107 135 288 31 Net income (loss) 105 134 385 (19 ) 2016 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 625 $ 584 $ 795 $ 621 Operating income 100 139 284 42 Net income 76 131 320 15 Quarterly operating results are affected by, among other things, MidAmerican Energy's seasonal retail electricity prices, the timing of recognition of federal renewable electricity production tax credits related to MidAmerican Energy's wind-powered generating facilities and the seasonal impact of weather on electricity and natural gas sales.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Quarterly Operating Results [Line Items]
Quarterly Financial Information [Text Block]	Unaudited Quarterly Operating Results 2017 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 696 $ 659 $ 815 $ 676 Operating income 107 136 288 31 Net income (loss) 102 131 383 (42 ) 2016 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 626 $ 585 $ 797 $ 623 Operating income 100 140 284 42 Net income 73 127 318 14 Quarterly operating results are affected by, among other things, MidAmerican Energy's seasonal retail electricity prices, the timing of recognition of federal renewable electricity production tax credits related to MidAmerican Energy's wind-powered generating facilities and the seasonal impact of weather on electricity and natural gas sales.
Nevada Power Company [Member]
Quarterly Operating Results [Line Items]
Quarterly Financial Information [Text Block]	Unaudited Quarterly Operating Results (in millions) Three-Month Periods Ended March 31, June 30, September 30, December 31, 2017 2017 2017 2017 Operating revenues $ 392 $ 574 $ 819 $ 421 Operating income 52 157 317 37 Net income 10 77 176 (8 ) Three-Month Periods Ended March 31, June 30, September 30, December 31, 2016 2016 2016 2016 Operating revenues $ 399 $ 525 $ 766 $ 393 Operating income 46 141 324 69 Net income 3 66 188 22
Sierra Pacific Power Company [Member]
Quarterly Operating Results [Line Items]
Quarterly Financial Information [Text Block]	Unaudited Quarterly Operating Results (in millions) Three-Month Periods Ended March 31, June 30, September 30, December 31, 2017 2017 2017 2017 Regulated electric operating revenue $ 159 $ 160 $ 215 $ 179 Regulated natural gas operating revenue 34 17 15 33 Operating income 46 36 75 41 Net income 24 17 44 24 Three-Month Periods Ended March 31, June 30, September 30, December 31, 2016 2016 2016 2016 Regulated electric operating revenue $ 170 $ 162 $ 207 $ 163 Regulated natural gas operating revenue 47 19 15 29 Operating income 41 28 69 42 Net income 17 10 38 19

Condensed Financial Statements

Condensed Financial Statements (Notes)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Condensed Financial Statements [Text Block]	Schedule I Berkshire Hathaway Energy Company Parent Company Only Condensed Balance Sheets As of December 31, (Amounts in millions) 2017 2016 ASSETS Current assets: Cash and cash equivalents $ 346 $ 33 Accounts receivable — 21 Accounts receivable - affiliate 60 — Notes receivable - affiliate 391 105 Other current assets 21 2 Total current assets 818 161 Investments in subsidiaries 34,019 33,400 Other investments 2,117 1,338 Goodwill 1,221 1,221 Other assets 1,155 1,171 Total assets $ 39,330 $ 37,291 LIABILITIES AND EQUITY Current liabilities: Accounts payable and other current liabilities $ 268 $ 357 Notes payable - affiliate 182 194 Short-term debt 3,331 834 Current portion of BHE senior debt 1,000 400 Total current liabilities 4,781 1,785 BHE senior debt 5,452 7,418 BHE junior subordinated debentures 100 944 Notes payable - affiliate 1 1,859 Other long-term liabilities 800 942 Total liabilities 11,134 12,948 Equity: BHE shareholders' equity: Common stock - 115 shares authorized, no par value, 77 shares issued and outstanding — — Additional paid-in capital 6,368 6,390 Retained earnings 22,206 19,448 Accumulated other comprehensive loss, net (398 ) (1,511 ) Total BHE shareholders' equity 28,176 24,327 Noncontrolling interest 20 16 Total equity 28,196 24,343 Total liabilities and equity $ 39,330 $ 37,291 The accompanying notes are an integral part of this financial statement schedule. Schedule I Berkshire Hathaway Energy Company Parent Company Only (continued) Condensed Statements of Operations For the years ended December 31, (Amounts in millions) 2017 2016 2015 Operating costs and expenses: General and administration $ 55 $ 51 $ 58 Depreciation and amortization 4 4 3 Total operating costs and expenses 59 55 61 Operating loss (59 ) (55 ) (61 ) Other income (expense): Interest expense (475 ) (527 ) (556 ) Other, net (369 ) 37 14 Total other income (expense) (844 ) (490 ) (542 ) Loss before income tax benefit and equity income (903 ) (545 ) (603 ) Income tax benefit (335 ) (285 ) (330 ) Equity income 3,441 2,805 2,646 Net income 2,873 2,545 2,373 Net income attributable to noncontrolling interest 3 3 3 Net income attributable to BHE shareholders $ 2,870 $ 2,542 $ 2,370 The accompanying notes are an integral part of this financial statement schedule. Schedule I Berkshire Hathaway Energy Company Parent Company Only (continued) Condensed Statements of Comprehensive Income For the years ended December 31, (Amounts in millions) 2017 2016 2015 Net income $ 2,873 $ 2,545 $ 2,373 Other comprehensive income (loss), net of tax 1,113 (603 ) (414 ) Comprehensive income 3,986 1,942 1,959 Comprehensive income attributable to noncontrolling interests 3 3 3 Comprehensive income attributable to BHE shareholders $ 3,983 $ 1,939 $ 1,956 The accompanying notes are an integral part of this financial statement schedule. Schedule I Berkshire Hathaway Energy Company Parent Company Only (continued) Condensed Statements of Cash Flows For the years ended December 31, (Amounts in millions) 2017 2016 2015 Cash flows from operating activities $ 2,450 $ 2,760 $ 2,528 Cash flows from investing activities: Investments in subsidiaries (1,566 ) (1,080 ) (1,506 ) Purchases of investments (71 ) (24 ) (36 ) Proceeds from sale of investments 68 20 47 Notes receivable from affiliate, net (305 ) (307 ) 19 Other, net (8 ) (5 ) (7 ) Net cash flows from investing activities (1,882 ) (1,396 ) (1,483 ) Cash flows from financing activities: Repayments of BHE senior debt (1,379 ) — — Repayments of BHE subordinated debt (944 ) (2,000 ) (850 ) Common stock purchases (19 ) — (36 ) Net proceeds from (repayments of) short-term debt 2,498 581 (142 ) Tender offer premium paid (406 ) — — Notes payable to affiliate, net — 69 4 Other, net (5 ) (4 ) (1 ) Net cash flows from financing activities (255 ) (1,354 ) (1,025 ) Net change in cash and cash equivalents 313 10 20 Cash and cash equivalents at beginning of year 33 23 3 Cash and cash equivalents at end of year $ 346 $ 33 $ 23 The accompanying notes are an integral part of this financial statement schedule. Schedule I BERKSHIRE HATHAWAY ENERGY COMPANY NOTES TO CONDENSED FINANCIAL STATEMENTS Basis of Presentation - The condensed financial information of BHE investments in subsidiaries are presented under the equity method of accounting. Under this method, the assets and liabilities of subsidiaries are not consolidated. The investments in subsidiaries are recorded in the Condensed Balance Sheets. The income from operations of subsidiaries is reported on a net basis as equity income in the Condensed Statements of Operations. Other investments - BHE 's investment in BYD Company Limited ("BYD") common stock is accounted for as an available-for-sale security with changes in fair value recognized in AOCI. As of December 31, 2017 and 2016 , the fair value of BHE 's investment in BYD common stock was $1,961 million and $1,185 million , respectively, which resulted in an unrealized gain of $1,729 million and $953 million as of December 31, 2017 and 2016 , respectively. Dividends and distributions from subsidiaries - Cash dividends paid to BHE by its subsidiaries for the years ended December 31, 2017 , 2016 and 2015 were $3.0 billion for each of the three years. In January and February 2018 , BHE received cash dividends from its subsidiaries totaling $158 million . Guarantees and commitments - BHE has issued guarantees up to a maximum of $236 million in support of various obligations of consolidated subsidiaries and commitments, subject to satisfaction of certain specified conditions, to provide equity contributions in support of renewable tax equity investments totaling $265 million . See the notes to the consolidated BHE financial statements in Part II, Item 8 for other disclosures regarding long-term obligations (Notes 8, 9 and 10) and shareholders' equity (Note 17).
MidAmerican Funding LLC [Member]
Condensed Financial Statements, Captions [Line Items]
Condensed Financial Statements [Text Block]	MIDAMERICAN FUNDING, LLC PARENT COMPANY ONLY NOTES TO CONDENSED FINANCIAL STATEMENTS Incorporated by reference are MidAmerican Funding, LLC and Subsidiaries Consolidated Statements of Changes in Equity for the three years ended December 31, 2017 in Part II, Item 8. Basis of Presentation - The condensed financial information of MidAmerican Funding, LLC's ("MidAmerican Funding's") investments in subsidiaries is presented under the equity method of accounting. Under this method, the assets and liabilities of subsidiaries are not consolidated. The investments in and advances to subsidiaries are recorded on the Condensed Balance Sheets. The income from operations of the subsidiaries is reported on a net basis as equity in undistributed earnings of subsidiary companies on the Condensed Statements of Operations. Payable to Affiliate - MHC, Inc. ("MHC") settles all obligations of MidAmerican Funding including primarily interest costs on, and repayments of, MidAmerican Funding's long-term debt. Net amounts paid by MHC on behalf of MidAmerican Funding totaled $130 million , $13 million and $13 million for the years 2017 , 2016 and 2015 , respectively. See the notes to the consolidated MidAmerican Funding financial statements in Part II, Item 8 for other disclosures.

Schedule II Consolidated Valuat

Schedule II Consolidated Valuation and Qualifying Accounts (Notes)	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts Disclosure [Line Items]
Consolidated Valuation and Qualifying Accounts [Text Block]	Schedule II BERKSHIRE HATHAWAY ENERGY COMPANY CONSOLIDATED VALUATION AND QUALIFYING ACCOUNTS FOR THE THREE YEARS ENDED DECEMBER 31, 2017 (Amounts in millions) Column B Column C Column E Balance at Charged Balance Column A Beginning to Acquisition Column D at End Description of Year Income Reserves Deductions of Year Reserves Deducted From Assets To Which They Apply: Reserve for uncollectible accounts receivable: Year ended 2017 $ 33 $ 42 $ — $ (35 ) $ 40 Year ended 2016 31 39 — (37 ) 33 Year ended 2015 37 33 — (39 ) 31 Reserves Not Deducted From Assets (1) : Year ended 2017 $ 13 $ 7 $ — $ (7 ) $ 13 Year ended 2016 13 5 — (5 ) 13 Year ended 2015 11 7 — (5 ) 13 The notes to the consolidated BHE financial statements are an integral part of this financial statement schedule. (1) Reserves not deducted from assets relate primarily to estimated liabilities for losses retained by BHE for workers compensation, public liability and property damage claims.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Valuation and Qualifying Accounts Disclosure [Line Items]
Consolidated Valuation and Qualifying Accounts [Text Block]	MIDAMERICAN FUNDING, LLC AND SUBSIDIARIES MHC INC. AND SUBSIDIARIES CONSOLIDATED VALUATION AND QUALIFYING ACCOUNTS FOR THE THREE YEARS ENDED DECEMBER 31, 2017 (Amounts in millions) Column B Column C Column E Balance at Additions Balance Column A Beginning Charged Column D at End Description of Year to Income Deductions of Year Reserves Deducted From Assets To Which They Apply: Reserve for uncollectible accounts receivable: Year ended 2017 $ 7 $ 8 $ (8 ) $ 7 Year ended 2016 $ 6 $ 7 $ (6 ) $ 7 Year ended 2015 $ 7 $ 7 $ (8 ) $ 6 Reserves Not Deducted From Assets (1) : Year ended 2017 $ 13 $ 7 $ (7 ) $ 13 Year ended 2016 $ 13 $ 5 $ (5 ) $ 13 Year ended 2015 $ 11 $ 7 $ (5 ) $ 13 (1) Reserves not deducted from assets include primarily estimated liabilities for losses retained by MidAmerican Funding and MHC for workers compensation, public liability and property damage claims.
MidAmerican Energy Company [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Consolidated Valuation and Qualifying Accounts [Text Block]	MIDAMERICAN ENERGY COMPANY VALUATION AND QUALIFYING ACCOUNTS FOR THE THREE YEARS ENDED DECEMBER 31, 2017 (Amounts in millions) Column B Column C Column E Balance at Additions Balance Column A Beginning Charged Column D at End Description of Year to Income Deductions of Year Reserves Deducted From Assets To Which They Apply: Reserve for uncollectible accounts receivable: Year ended 2017 $ 7 $ 8 $ (8 ) $ 7 Year ended 2016 $ 6 $ 7 $ (6 ) $ 7 Year ended 2015 $ 7 $ 7 $ (8 ) $ 6 Reserves Not Deducted From Assets (1) : Year ended 2017 $ 13 $ 7 $ (7 ) $ 13 Year ended 2016 $ 13 $ 5 $ (5 ) $ 13 Year ended 2015 $ 11 $ 7 $ (5 ) $ 13 (1) Reserves not deducted from assets include estimated liabilities for losses retained by MidAmerican Energy for workers compensation, public liability and property damage claims.

Discontinued Operations Discont

Discontinued Operations Discontinued Operations - Unregulated Retail Services [Member]	12 Months Ended
	Dec. 31, 2017
MidAmerican Funding, LLC and Subsidiaries [Domain]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Disclosure	Discontinued Operations Refer to Note 3 of MidAmerican Energy's Notes to Financial Statements. The transfer of MidAmerican Energy's unregulated retail services business to a subsidiary of BHE repaid $117 million of MHC's note payable to BHE.
MidAmerican Energy Company [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Disclosure	Discontinued Operations On January 1, 2016, MidAmerican Energy transferred the assets and liabilities of its unregulated retail services business to a subsidiary of BHE. The transfer was made at MidAmerican Energy's carrying value of the assets, liabilities and AOCI as of December 31, 2015, totaling $90 million , and was recorded by MidAmerican Energy as a noncash dividend. Financial results of the unregulated retail services business for the year ended December 31, 2015 have been reclassified to discontinued operations in the Statement of Operations. Significant line items constituting pre-tax income from discontinued operations and total cash flows from operating activities for the years ended December 31 are as follows (in millions): 2015 Operating revenue $ 905 Cost of sales $ 854 Cash flows from operating activities $ 30

Summary of Significant Accoun41

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Allowance for Doubtful Accounts [Line Items]
Basis of consolidation and presentation [Policy Text Block]	Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of BHE and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. The Consolidated Statements of Operations include the revenue and expenses of any acquired entities from the date of acquisition. Intercompany accounts and transactions have been eliminated.
Use of estimates in preparation of financial statements [Policy Text Block]	Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; impairment of goodwill; recovery of long-lived assets; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; fair value of assets acquired and liabilities assumed in business combinations; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements.
Accounting for the effects of certain types of regulation [Policy Text Block]	Accounting for the Effects of Certain Types of Regulation PacifiCorp, MidAmerican Energy, Nevada Power, Sierra Pacific, Northern Natural Gas, Kern River and ALP (the "Regulated Businesses") prepare their financial statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, the Regulated Businesses defer the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. The Company continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit the Regulated Businesses' ability to recover their costs. The Company believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at the federal, state and provincial levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be recognized in net income, returned to customers or re-established as accumulated other comprehensive income (loss) ("AOCI").
Fair value measurement [Policy Text Block]	Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Alternative valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange.
Cash equivalent and restricted cash and investments [Policy Text Block]	Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other current assets and investments and restricted cash and investments on the Consolidated Balance Sheets.
Investments [Policy Text Block]	Investments The Company's management determines the appropriate classification of investments in debt and equity securities at the acquisition date and reevaluates the classification at each balance sheet date. Investments and restricted cash and investments that management does not intend to use or is restricted from using in current operations are presented as noncurrent on the Consolidated Balance Sheets. Available-for-sale securities are carried at fair value with realized gains and losses, as determined on a specific identification basis, recognized in earnings and unrealized gains and losses recognized in AOCI, net of tax. Realized and unrealized gains and losses on securities in a trust related to the decommissioning of nuclear generation assets are recorded as a net regulatory liability since the Company expects to recover costs for these activities through regulated rates. Trading securities are carried at fair value with realized and unrealized gains and losses recognized in earnings. Held-to-maturity securities are carried at amortized cost, reflecting the ability and intent to hold the securities to maturity. The Company utilizes the equity method of accounting with respect to investments when it possesses the ability to exercise significant influence, but not control, over the operating and financial policies of the investee. The ability to exercise significant influence is presumed when an investor possesses more than 20% of the voting interests of the investee. This presumption may be overcome based on specific facts and circumstances that demonstrate the ability to exercise significant influence is restricted. In applying the equity method, the Company records the investment at cost and subsequently increases or decreases the carrying value of the investment by the Company's share of the net earnings or losses and other comprehensive income (loss) ("OCI") of the investee. The Company records dividends or other equity distributions as reductions in the carrying value of the investment. Certain equity investments are presented on the Consolidated Balance Sheets net of related investment tax credits. Investments gains and losses arise when investments are sold (as determined on a specific identification basis) or are other-than-temporarily impaired. If a decline in value of an investment below cost is deemed other than temporary, the cost of the investment is written down to fair value, with a corresponding charge to earnings. Factors considered in judging whether an impairment is other than temporary include: the financial condition, business prospects and creditworthiness of the issuer; the relative amount of the decline; the Company's ability and intent to hold the investment until the fair value recovers; and the length of time that fair value has been less than cost. Impairment losses on equity securities are charged to earnings. With respect to an investment in a debt security, any resulting impairment loss is recognized in earnings if the Company intends to sell, or expects to be required to sell, the debt security before its amortized cost is recovered. If the Company does not expect to ultimately recover the amortized cost basis even if it does not intend to sell the security, the credit loss component is recognized in earnings and any difference between fair value and the amortized cost basis, net of the credit loss, is reflected in OCI. For regulated investments, any impairment charge is offset by the establishment of a regulatory asset to the extent recovery in regulated rates is probable.
Allowance for doubtful accounts [Policy Text Block]	Allowance for Doubtful Accounts Trade receivables are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on the Company's assessment of the collectibility of amounts owed to the Company by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. As of December 31, 2017 and 2016 , the allowance for doubtful accounts totaled $40 million and $33 million , respectively, and is included in trade receivables, net on the Consolidated Balance Sheets.
Derivatives [Policy Text Block]	Derivatives The Company employs a number of different derivative contracts, which may include forwards, futures, options, swaps and other agreements, to manage its commodity price, interest rate, and foreign currency exchange rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Cash collateral received from or paid to counterparties to secure derivative contract assets or liabilities in excess of amounts offset is included in other current assets on the Consolidated Balance Sheets. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked-to-market and settled amounts are recognized as operating revenue or cost of sales on the Consolidated Statements of Operations. For the Company's derivatives not designated as hedging contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For the Company's derivatives not designated as hedging contracts and for which changes in fair value are not recorded as regulatory assets and liabilities, unrealized gains and losses are recognized on the Consolidated Statements of Operations as operating revenue for sales contracts; cost of sales and operating expense for purchase contracts and electricity, natural gas and fuel swap contracts; and other, net for interest rate swap derivatives. For the Company's derivatives designated as hedging contracts, the Company formally assesses, at inception and thereafter, whether the hedging contract is highly effective in offsetting changes in the hedged item. The Company formally documents hedging activity by transaction type and risk management strategy. Changes in the estimated fair value of a derivative contract designated and qualified as a cash flow hedge, to the extent effective, are included on the Consolidated Statements of Changes in Equity as AOCI, net of tax, until the contract settles and the hedged item is recognized in earnings. The Company discontinues hedge accounting prospectively when it has determined that a derivative contract no longer qualifies as an effective hedge, or when it is no longer probable that the hedged forecasted transaction will occur. When hedge accounting is discontinued because the derivative contract no longer qualifies as an effective hedge, future changes in the estimated fair value of the derivative contract are charged to earnings. Gains and losses related to discontinued hedges that were previously recorded in AOCI will remain in AOCI until the contract settles and the hedged item is recognized in earnings, unless it becomes probable that the hedged forecasted transaction will not occur at which time associated deferred amounts in AOCI are immediately recognized in earnings.
Inventories [Policy Text Block]	Inventories Inventories consist mainly of fuel, which includes coal stocks, stored gas and fuel oil, totaling $352 million and $402 million as of December 31, 2017 and 2016 , respectively, and materials and supplies totaling $536 million and $523 million as of December 31, 2017 and 2016 , respectively. The cost of materials and supplies, coal stocks and fuel oil is determined primarily using the average cost method. The cost of stored gas is determined using either the last-in-first-out ("LIFO") method or the lower of average cost or market. With respect to inventories carried at LIFO cost, the replacement cost would be $22 million and $27 million higher as of December 31, 2017 and 2016 , respectively.
Property, plant and equipment, net - general [Policy Text Block]	Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. The Company capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include capitalized interest, including debt allowance for funds used during construction ("AFUDC"), and equity AFUDC, as applicable to the Regulated Businesses. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. Additionally, MidAmerican Energy has regulatory arrangements in Iowa in which the carrying cost of certain utility plant has been reduced for amounts associated with electric returns on equity exceeding specified thresholds. Depreciation and amortization are generally computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by the Company's various regulatory authorities. Depreciation studies are completed by the Regulated Businesses to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as either a cost of removal regulatory liability or an ARO liability on the Consolidated Balance Sheets, depending on whether the obligation meets the requirements of an ARO. As actual removal costs are incurred, the associated liability is reduced. Generally when the Company retires or sells a component of regulated property, plant and equipment, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of regulated facilities, is capitalized by the Regulated Businesses as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. AFUDC is computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC") and the Alberta Utilities Commission ("AUC"). After construction is completed, the Company is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets.
Property, plant and equipment, net - asset retirement obligations [Policy Text Block]	Asset Retirement Obligations The Company recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. The Company's AROs are primarily related to the decommissioning of nuclear generating facilities and obligations associated with its other generating facilities and offshore natural gas pipelines. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. For the Regulated Businesses, the difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability.
Property, plant and equipment, net - impairment [Policy Text Block]	Impairment The Company evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. The impacts of regulation are considered when evaluating the carrying value of regulated assets.
Goodwill [Policy Text Block]	Goodwill Goodwill represents the excess of the purchase price over the fair value of identifiable net assets acquired in business combinations. The Company evaluates goodwill for impairment at least annually and completed its annual review as of October 31. When evaluating goodwill for impairment, the Company estimates the fair value of the reporting unit. If the carrying amount of a reporting unit, including goodwill, exceeds the estimated fair value, then the identifiable assets, including identifiable intangible assets, and liabilities of the reporting unit are estimated at fair value as of the current testing date. The excess of the estimated fair value of the reporting unit over the current estimated fair value of net assets establishes the implied value of goodwill. The excess of the recorded goodwill over the implied goodwill value is charged to earnings as an impairment loss. Significant judgment is required in estimating the fair value of the reporting unit and performing goodwill impairment tests. The Company uses a variety of methods to estimate a reporting unit's fair value, principally discounted projected future net cash flows. Key assumptions used include, but are not limited to, the use of estimated future cash flows; multiples of earnings; and an appropriate discount rate. In estimating future cash flows, the Company incorporates current market information, as well as historical factors. As such, the determination of fair value incorporates significant unobservable inputs. During 2017 , 2016 and 2015 , the Company did not record any material goodwill impairments. The Company records goodwill adjustments for (a) the tax benefit associated with the excess of tax-deductible goodwill over the reported amount of goodwill and (b) changes to the purchase price allocation prior to the end of the measurement period, which is not to exceed one year from the acquisition date.
Revenue recognition [Policy Text Block]	Revenue Recognition Energy Businesses Revenue from energy business customers is recognized as electricity or natural gas is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31, 2017 and 2016 , unbilled revenue was $665 million and $643 million , respectively, and is included in trade receivables, net on the Consolidated Balance Sheets. Rates for energy businesses are established by regulators or contractual arrangements. When preliminary regulated rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. The Company records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations. Real Estate Commission Revenue, Mortgage Revenue and Franchise Royalty Fees Commission revenue from real estate brokerage transactions and related amounts due to agents are recognized when a real estate transaction is closed. Title and escrow closing fee revenue from real estate transactions and related amounts due to the title insurer are recognized at closing. Mortgage fee revenue consists of amounts earned related to application and underwriting fees, and fees on canceled loans. Fees associated with the origination and acquisition of mortgage loans are recognized as earned. Franchise royalty fees are based on a percentage of commissions earned by franchisees on real estate sales and are recognized when the sale closes.
Unamortized debt premiums, discounts and financing costs [Policy Text Block]	Unamortized Debt Premiums, Discounts and Debt Issuance Costs Premiums, discounts and debt issuance costs incurred for the issuance of long-term debt are amortized over the term of the related financing using the effective interest method.
Foreign currency [Policy Text Block]	Foreign Currency The accounts of foreign-based subsidiaries are measured in most instances using the local currency of the subsidiary as the functional currency. Revenue and expenses of these businesses are translated into United States dollars at the average exchange rate for the period. Assets and liabilities are translated at the exchange rate as of the end of the reporting period. Gains or losses from translating the financial statements of foreign-based operations are included in equity as a component of AOCI. Gains or losses arising from transactions denominated in a currency other than the functional currency of the entity that is party to the transaction are included in earnings.
Income taxes [Policy Text Block]	Income Taxes Berkshire Hathaway includes the Company in its consolidated United States federal income tax return. The Company's provision for income taxes has been computed on a stand-alone basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of OCI are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that the Company's regulated businesses deems probable to be passed on to their customers in most state and provincial jurisdictions are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties or as prescribed by various regulatory jurisdictions.
Unremitted earnings in foreign investment [Policy Text Block]	The 2017 Tax Reform also creates a one-time repatriation tax on the Company's undistributed foreign corporations' post-1986 accumulated earnings and profits. Therefore, the cumulative undistributed foreign earnings were deemed repatriated to the United States as of December 31, 2017. The Company currently does not believe the deemed repatriation has altered the Company's existing assertion that undistributed earnings will be reinvested indefinitely; however, the Company periodically evaluates its capital requirements and that conclusion could change. As a result of the 2017 Tax Reform, future undistributed earnings are not expected to be subject to tax in the United States.
Income tax uncertainties [Policy Text Block]	In determining the Company's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by the Company's various regulatory jurisdictions. The Company's income tax returns are subject to continuous examinations by federal, state, local and foreign income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. The Company recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of the Company's federal, state, local and foreign income tax examinations is uncertain, the Company believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on the Company's consolidated financial results. The Company's unrecognized tax benefits are primarily included in accrued property, income and other taxes and other long-term liabilities on the Consolidated Balance Sheets. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2018-02, which amends FASB Accounting Standards Codification ("ASC") Topic 220, "Income Statement - Reporting Comprehensive Income." The amendments in this guidance require a reclassification from accumulated other comprehensive income to retained earnings for the stranded tax effects that were created from the enactment of the 2017 Tax Reform. The reclassification is the difference between the historical income tax rates and the enacted rate for the items previously recorded in accumulated other comprehensive income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted retrospectively to each period(s) in which the effect of the change in the 2017 Tax Reform is recognized. Considering the significant components of the Company's accumulated other comprehensive income relate to (a) unrecognized amounts on retirement benefits of foreign pension plans and (b) unrealized gains on available-for-sale securities, which were reclassified as required by ASU No. 2016-01 that was adopted on January 1, 2018, the adoption of ASU No. 2018-02 will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2017, the FASB issued ASU No. 2017-12, which amends FASB ASC Topic 815, "Derivatives and Hedging." The amendments in this guidance update the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements, expands an entity's ability to hedge non-financial and financial risk components and reduces complexity in fair value hedges of interest rate risk. In addition, it eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in fair value of a hedging instrument to be presented in the same income statement line as the hedged item and also eases certain documentation and assessment requirements. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach by means of a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The Company is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In March 2017, the FASB issued ASU No. 2017-07, which amends FASB ASC Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, “Statement of Cash Flows - Overall.” The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. The Company plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The Company adopted this guidance effective January 1, 2018 with a cumulative-effect increase to retained earnings of $1,085 million and a corresponding decrease to AOCI. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. The Company adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when the Company has the right to invoice as it corresponds directly with the value to the customer of the Company's performance to date. The Company's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by regulated energy, nonregulated energy and real estate, with further disaggregation of regulated energy by customer class and line of business and real estate by line of business.
PacifiCorp [Member]
Allowance for Doubtful Accounts [Line Items]
Basis of consolidation and presentation [Policy Text Block]	Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of PacifiCorp and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated.
Use of estimates in preparation of financial statements [Policy Text Block]	Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements.
Accounting for the effects of certain types of regulation [Policy Text Block]	Accounting for the Effects of Certain Types of Regulation PacifiCorp prepares its financial statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, PacifiCorp defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in rates occur. PacifiCorp continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit PacifiCorp's ability to recover its costs. PacifiCorp believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future rates, the related regulatory assets and liabilities will be written off to net income or re-established as accumulated other comprehensive income (loss) ("AOCI").
Fair value measurement [Policy Text Block]	Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange.
Cash equivalent and restricted cash and investments [Policy Text Block]	Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other current assets and other assets on the Consolidated Balance Sheets.
Investments [Policy Text Block]	Investments Available-for-sale securities are carried at fair value with realized gains and losses, as determined on a specific identification basis, recognized in earnings and unrealized gains and losses recognized in AOCI, net of tax. As of December 31, 2017 and 2016 , PacifiCorp had no unrealized gains and losses on available-for-sale securities. Trading securities are carried at fair value with realized and unrealized gains and losses recognized in earnings. PacifiCorp utilizes the equity method of accounting with respect to investments when it possesses the ability to exercise significant influence, but not control, over the operating and financial policies of the investee. The ability to exercise significant influence is presumed when an investor possesses more than 20% of the voting interests of the investee. This presumption may be overcome based on specific facts and circumstances that demonstrate the ability to exercise significant influence is restricted. In applying the equity method, PacifiCorp records the investment at cost and subsequently increases or decreases the carrying value of the investment by PacifiCorp's proportionate share of the net earnings or losses and other comprehensive income (loss) ("OCI") of the investee. PacifiCorp records dividends or other equity distributions as reductions in the carrying value of the investment.
Allowance for doubtful accounts [Policy Text Block]	Allowance for Doubtful Accounts Accounts receivable are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on PacifiCorp's assessment of the collectibility of amounts owed to PacifiCorp by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 7 $ 7 $ 7 Charged to operating costs and expenses, net 15 12 10 Write-offs, net (12 ) (12 ) (10 ) Ending balance $ 10 $ 7 $ 7
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 7 $ 7 $ 7 Charged to operating costs and expenses, net 15 12 10 Write-offs, net (12 ) (12 ) (10 ) Ending balance $ 10 $ 7 $ 7
Derivatives [Policy Text Block]	Derivatives PacifiCorp employs a number of different derivative contracts, which may include forwards, options, swaps and other agreements, to manage price risk for electricity, natural gas and other commodities and interest rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked-to-market and settled amounts are recognized as operating revenue or energy costs on the Consolidated Statements of Operations. For PacifiCorp's derivative contracts, the settled amount is generally included in rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in rates are recorded as regulatory liabilities or assets. For a derivative contract not probable of inclusion in rates, changes in the fair value are recognized in earnings.
Inventories [Policy Text Block]	Inventories Inventories consist mainly of materials and supplies totaling $235 million and $228 million as of December 31, 2017 , and 2016 , respectively, and fuel stocks, totaling $198 million and $215 million as of December 31, 2017 , and 2016 , respectively. Inventories are stated at the lower of average cost or net realizable value.
Property, plant and equipment, net - general [Policy Text Block]	Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. PacifiCorp capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs, which include debt and equity allowance for funds used during construction ("AFUDC"). The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. Depreciation and amortization are generally computed on the straight-line method based on composite asset class lives prescribed by PacifiCorp's various regulatory authorities or over the assets' estimated useful lives. Depreciation studies are completed periodically to determine the appropriate composite asset class lives, net salvage and depreciation rates. These studies are reviewed and rates are ultimately approved by the various regulatory authorities. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as either a cost of removal regulatory liability or an ARO liability on the Consolidated Balance Sheets, depending on whether the obligation meets the requirements of an ARO. As actual removal costs are incurred, the associated liability is reduced. Generally when PacifiCorp retires or sells a component of regulated property, plant and equipment, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of property, plant and equipment, is capitalized as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. AFUDC is computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC"). After construction is completed, PacifiCorp is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets.
Property, plant and equipment, net - asset retirement obligations [Policy Text Block]	Asset Retirement Obligations PacifiCorp recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. PacifiCorp's AROs are primarily associated with its generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability.
Property, plant and equipment, net - impairment [Policy Text Block]	Impairment The Company evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. The impacts of regulation are considered when evaluating the carrying value of regulated assets.
Revenue recognition [Policy Text Block]	Revenue Recognition Revenue is recognized as electricity is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31, 2017 and 2016 , unbilled revenue was $255 million and $275 million , respectively, and is included in accounts receivable, net on the Consolidated Balance Sheets. Rates charged are established by regulators or contractual arrangements. The determination of sales to individual customers is based on the reading of the customer's meter, which is performed on a systematic basis throughout the month. At the end of each month, energy provided to customers since the date of the last meter reading is estimated, and the corresponding unbilled revenue is recorded. The estimate is reversed in the following month and actual revenue is recorded based on subsequent meter readings. The monthly unbilled revenues of PacifiCorp are determined by the estimation of unbilled energy provided during the period, the assignment of unbilled energy provided to customer classes and the average rate per customer class. Factors that can impact the estimate of unbilled energy include, but are not limited to, seasonal weather patterns, total volumes supplied to the system, line losses, economic impacts and composition of sales among customer classes. PacifiCorp records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations.
Income taxes [Policy Text Block]	Income Taxes Berkshire Hathaway includes PacifiCorp in its consolidated United States federal income tax return. Consistent with established regulatory practice, PacifiCorp's provision for income taxes has been computed on a stand-alone basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of OCI are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that PacifiCorp deems probable to be passed on to its customers in most state jurisdictions are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties or as prescribed by various regulatory jurisdictions. Investment tax credits are included in other long-term liabilities on the Consolidated Balance Sheets and were $16 million and $18 million as of December 31, 2017 and 2016 , respectively.
Income tax uncertainties [Policy Text Block]	In determining PacifiCorp's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by PacifiCorp's various regulatory jurisdictions. PacifiCorp's income tax returns are subject to continuous examinations by federal, state and local income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. PacifiCorp recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of PacifiCorp's federal, state and local income tax examinations is uncertain, PacifiCorp believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on PacifiCorp's consolidated financial results. PacifiCorp's unrecognized tax benefits are primarily included in other long-term liabilities on the Consolidated Balance Sheets. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations.
Segment reporting	Segment Information PacifiCorp currently has one segment, which includes its regulated electric utility operations.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. PacifiCorp adopted this guidance January 1, 2018 and the adoption of this guidance will not have a material impact on the Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. PacifiCorp plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. PacifiCorp adopted this guidance on January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when PacifiCorp has the right to invoice as it corresponds directly with the value to the customer of PacifiCorp's performance to date. PacifiCorp plans to quantitatively disaggregate revenue in the required financial statement footnote by customer class.
MidAmerican Energy Company [Member]
Allowance for Doubtful Accounts [Line Items]
Use of estimates in preparation of financial statements [Policy Text Block]	Use of Estimates in Preparation of Financial Statements The preparation of the Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Financial Statements.
Accounting for the effects of certain types of regulation [Policy Text Block]	A ccounting for the Effects of Certain Types of Regulation MidAmerican Energy's utility operations are subject to the regulation of the Iowa Utilities Board ("IUB"), the Illinois Commerce Commission ("ICC"), the South Dakota Public Utilities Commission, and the Federal Energy Regulatory Commission ("FERC"). MidAmerican Energy's accounting policies and the accompanying Financial Statements conform to GAAP applicable to rate-regulated enterprises and reflect the effects of the ratemaking process. MidAmerican Energy prepares its financial statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, MidAmerican Energy defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. MidAmerican Energy continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition, that could limit MidAmerican Energy's ability to recover its costs. MidAmerican Energy believes the application of the guidance for regulated operations is appropriate, and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be written off to net income, returned to customers or re-established as accumulated other comprehensive income (loss) ("AOCI").
Fair value measurement [Policy Text Block]	Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange.
Cash equivalent and restricted cash and investments [Policy Text Block]	Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other current assets and restricted cash and investments on the Balance Sheets.
Investments [Policy Text Block]	Investments MidAmerican Energy's management determines the appropriate classification of investments in debt and equity securities at the acquisition date and reevaluates the classification at each balance sheet date. Investments that management does not intend to use or is restricted from using in current operations are presented as noncurrent on the Balance Sheets. Available-for-sale securities are carried at fair value with realized gains and losses, as determined on a specific identification basis, recognized in earnings and unrealized gains and losses recognized in AOCI, net of tax. Realized and unrealized gains and losses on securities in a trust related to the decommissioning of the Quad Cities Generating Station Units 1 and 2 ("Quad Cities Station") are recorded as a net regulatory liability because MidAmerican Energy expects to recover costs for these activities through regulated rates. Held-to-maturity securities are carried at amortized cost, reflecting the ability and intent to hold the securities to maturity. Investments gains and losses arise when investments are sold (as determined on a specific identification basis) or are other-than-temporarily impaired. If a decline in value of an investment below cost is deemed other than temporary, the cost of the investment is written down to fair value, with a corresponding charge to earnings. Factors considered in judging whether an impairment is other than temporary include: the financial condition, business prospects and creditworthiness of the issuer; the relative amount of the decline; MidAmerican Energy's ability and intent to hold the investment until the fair value recovers; and the length of time that fair value has been less than cost. Impairment losses on equity securities are charged to earnings. With respect to an investment in a debt security, any resulting impairment loss is recognized in earnings if MidAmerican Energy intends to sell, or expects to be required to sell, the debt security before its amortized cost is recovered. If MidAmerican Energy does not expect to ultimately recover the amortized cost basis even if it does not intend to sell the security, the credit loss component is recognized in earnings and any difference between fair value and the amortized cost basis, net of the credit loss, is reflected in other comprehensive income (loss) ("OCI"). For regulated investments, any impairment charge is offset by the establishment of a regulatory asset to the extent recovery in regulated rates is probable.
Allowance for doubtful accounts [Policy Text Block]	Allowance for Doubtful Accounts Receivables are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on MidAmerican Energy's assessment of the collectibility of amounts owed to it by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. As of December 31, 2017 and 2016 , the allowance for doubtful accounts totaled $7 million and is included in receivables, net on the Balance Sheets.
Derivatives [Policy Text Block]	Derivatives MidAmerican Energy employs a number of different derivative contracts, including forwards, futures, options, swaps and other agreements, to manage price risk for electricity, natural gas and other commodities, and interest rate risk. Derivative contracts are recorded on the Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Cash collateral received from or paid to counterparties to secure derivative contract assets or liabilities in excess of amounts offset is included in other current assets on the Balance Sheets. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked to market, and settled amounts are recognized as operating revenue or cost of sales on the Statements of Operations. For MidAmerican Energy's derivatives not designated as hedging contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For MidAmerican Energy's derivatives designated as hedging contracts, MidAmerican Energy formally assesses, at inception and thereafter, whether the hedging contract is highly effective in offsetting changes in the hedged item. MidAmerican Energy formally documents hedging activity by transaction type and risk management strategy. Changes in the estimated fair value of a derivative contract designated and qualified as a cash flow hedge, to the extent effective, are included on the Statements of Changes in Equity as AOCI, net of tax, until the contract settles and the hedged item is recognized in earnings. All of MidAmerican Energy's derivatives designated as cash flow hedges and the related AOCI were transferred to a subsidiary of BHE on January 1, 2016, as discussed in Note 3 .
Inventories [Policy Text Block]	Inventories Inventories consist mainly of coal stocks, totaling $117 million and $137 million as of December 31, 2017 and 2016 , respectively, materials and supplies, totaling $100 million and $99 million as of December 31, 2017 and 2016 , respectively, and natural gas in storage, totaling $24 million as of December 31, 2017 and 2016 . The cost of materials and supplies, coal stocks and fuel oil is determined using the average cost method. The cost of stored natural gas is determined using the last-in-first-out method. With respect to stored natural gas, the replacement cost would be $22 million and $27 million higher as of December 31, 2017 and 2016 , respectively.
Property, plant and equipment, net - general [Policy Text Block]	Utility Plant, Net General Additions to utility plant are recorded at cost. MidAmerican Energy capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include debt allowance for funds used during construction ("AFUDC") and equity AFUDC. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. Additionally, MidAmerican Energy has regulatory arrangements in Iowa in which the carrying cost of certain utility plant has been reduced for amounts associated with electric returns on equity exceeding specified thresholds and energy benefits associated with certain wind-powered generation. Amounts expensed under this arrangement are included as a component of depreciation and amortization. Depreciation and amortization for MidAmerican Energy's utility operations are computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by its various regulatory authorities. Depreciation studies are completed by MidAmerican Energy to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as either a cost of removal regulatory liability or an ARO liability on the Balance Sheets, depending on whether the obligation meets the requirements of an ARO. As actual removal costs are incurred, the associated liability is reduced. Generally, when MidAmerican Energy retires or sells a component of utility plant, it charges the original cost, net of any proceeds from the disposition to accumulated depreciation. Any gain or loss on disposals of nonregulated assets is recorded through earnings. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of its regulated facilities, is capitalized by MidAmerican Energy as a component of utility plant, with offsetting credits to the Statements of Operations. AFUDC is computed based on guidelines set forth by the FERC. After construction is completed, MidAmerican Energy is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets.
Property, plant and equipment, net - asset retirement obligations [Policy Text Block]	Asset Retirement Obligations MidAmerican Energy recognizes AROs when it has a legal obligation to perform decommissioning or removal activities upon retirement of an asset. MidAmerican Energy's AROs are primarily related to decommissioning of the Quad Cities Station and obligations associated with its other generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to utility plant) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in utility plant, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability.
Property, plant and equipment, net - impairment [Policy Text Block]	Impairment MidAmerican Energy evaluates long-lived assets for impairment, including utility plant, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value. The impacts of regulation are considered when evaluating the carrying value of regulated assets. For all other assets, any resulting impairment loss is reflected on the Statements of Operations.
Revenue recognition [Policy Text Block]	Revenue Recognition Revenue from electric and natural gas customers is recognized as electricity or natural gas is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31, 2017 and 2016 , unbilled revenue was $89 million and $87 million , respectively, and is included in receivables, net on the Balance Sheets. The determination of customer billings is based on a systematic reading of customer meters and applicable rates. At the end of each month, amounts of energy provided to customers since the date of the last meter reading are estimated, and the corresponding unbilled revenue is recorded. Factors that can impact the estimate of unbilled energy include, but are not limited to, seasonal weather patterns, total volumes supplied to the system, line losses, economic impacts and composition of customer classes. Unbilled revenue is reversed in the following month and billed revenue is recorded based on the subsequent meter readings. All of MidAmerican Energy's regulated retail electric and gas sales are subject to energy adjustment clauses. MidAmerican Energy also has costs that are recovered, at least in part, through bill riders, including demand-side management and certain transmission costs. The clauses and riders allow MidAmerican Energy to adjust the amounts charged for electric and gas service as the related costs change. The costs recovered in revenue through use of the adjustment clauses and bill riders are charged to expense in the same year the related revenue is recognized. At any given time, these costs may be over or under collected from customers. The total under collection included in receivables at December 31, 2017 and 2016 , was $72 million and $31 million , respectively. MidAmerican Energy collects from its customers sales and excise taxes assessed by governmental authorities on transactions with customers and later remits the collected taxes to the appropriate authority. If the obligation to pay a particular tax resides with the customer, MidAmerican Energy reports such taxes collected on a net basis and, accordingly, they do not affect the Statement of Operations. Taxes for which the obligation resides with MidAmerican Energy are reported on a gross basis in operating revenue and operating expenses. The amounts reported on a gross basis are not material.
Unamortized debt premiums, discounts and financing costs [Policy Text Block]	Unamortized Debt Premiums, Discounts and Issuance Costs Premiums, discounts and issuance costs incurred for the issuance of long-term debt are amortized over the term of the related financing using the effective interest method.
Income taxes [Policy Text Block]	Income Taxes Berkshire Hathaway includes MidAmerican Funding and MidAmerican Energy in its consolidated United States federal income tax return. MidAmerican Funding's and MidAmerican Energy's provisions for income taxes have been computed on a stand-alone basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of OCI are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21%. Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that MidAmerican Energy deems probable to be passed on to its customers in most state jurisdictions are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties or as prescribed by various regulatory jurisdictions.
Income tax uncertainties [Policy Text Block]	In determining MidAmerican Funding's and MidAmerican Energy's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by MidAmerican Energy's various regulatory jurisdictions. MidAmerican Funding's and MidAmerican Energy's income tax returns are subject to continuous examinations by federal, state and local tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. MidAmerican Funding and MidAmerican Energy recognize the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of their federal, state and local income tax examinations is uncertain, each company believes it has made adequate provisions for its income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on its consolidated financial results. MidAmerican Funding's and MidAmerican Energy's unrecognized tax benefits are primarily included in taxes accrued and other long-term liabilities on their respective Consolidated Balance Sheets. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, “Statement of Cash Flows - Overall.” The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively, wherein the statement of cash flows of each period presented should be adjusted to reflect the new guidance. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. MidAmerican Energy plans to adopt this guidance effective January 1, 2019, and is currently evaluating the impact on its Financial Statements and disclosures included within Notes to Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No.2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. MidAmerican Energy adopted this guidance effective January 1, 2018, under the modified retrospective method and the adoption will not have an impact on its Financial Statements but will increase the disclosures included within Notes to Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized equal to what MidAmerican Energy has the right to invoice as it corresponds directly with the value to the customer of MidAmerican Energy's performance to date. MidAmerican Energy's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by customer class for each segment.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Allowance for Doubtful Accounts [Line Items]
Basis of consolidation and presentation [Policy Text Block]	Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of MidAmerican Funding and its subsidiaries in which it held a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated, other than those between rate-regulated operations.
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	Goodwill Goodwill represents the excess of the purchase price over the fair value of identifiable net assets acquired when MidAmerican Funding purchased MHC. MidAmerican Funding evaluates goodwill for impairment at least annually and completed its annual review as of October 31. When evaluating goodwill for impairment, MidAmerican Funding estimates the fair value of the reporting unit. If the carrying amount of a reporting unit, including goodwill, exceeds the estimated fair value, then the identifiable assets, including identifiable intangible assets, and liabilities of the reporting unit are estimated at fair value as of the current testing date. The excess of the estimated fair value of the reporting unit over the current estimated fair value of net assets establishes the implied value of goodwill. The excess of the recorded goodwill over the implied goodwill value is charged to earnings as an impairment loss. Significant judgment is required in estimating the fair value of the reporting unit and performing goodwill impairment tests. MidAmerican Funding uses a variety of methods to estimate a reporting unit's fair value, principally discounted projected future net cash flows. Key assumptions used include, but are not limited to, the use of estimated future cash flows; multiples of earnings; and an appropriate discount rate. In estimating future cash flows, MidAmerican Funding incorporates current market information, as well as historical factors. As such, the determination of fair value incorporates significant unobservable inputs. During 2017 , 2016 and 2015 , MidAmerican Funding did not record any goodwill impairments.
Nevada Power Company [Member]
Allowance for Doubtful Accounts [Line Items]
Basis of consolidation and presentation [Policy Text Block]	Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of Nevada Power and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated. The Consolidated Statements of Comprehensive Income have been omitted as net income equals comprehensive income for the years ended December 31, 2017 , 2016 and 2015 . Certain amounts in the prior period Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported operating income, net income or retained earnings.
Use of estimates in preparation of financial statements [Policy Text Block]	Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; recovery of long-lived assets; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements.
Accounting for the effects of certain types of regulation [Policy Text Block]	Accounting for the Effects of Certain Types of Regulation Nevada Power prepares its Consolidated Financial Statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, Nevada Power defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. Nevada Power continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit Nevada Power 's ability to recover its costs. Nevada Power believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be written off to net income, returned to customers or re-established as accumulated other comprehensive income (loss).
Fair value measurement [Policy Text Block]	Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange.
Cash equivalent and restricted cash and investments [Policy Text Block]	Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other assets and other current assets on the Consolidated Balance Sheets.
Allowance for doubtful accounts [Policy Text Block]	Allowance for Doubtful Accounts Accounts receivable are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on Nevada Power 's assessment of the collectibility of amounts owed to Nevada Power by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. Nevada Power also has the ability to assess deposits on customers who have delayed payments or who are deemed to be a credit risk. The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 12 $ 13 $ 14 Charged to operating costs and expenses, net 15 16 16 Write-offs, net (11 ) (17 ) (17 ) Ending balance $ 16 $ 12 $ 13
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 12 $ 13 $ 14 Charged to operating costs and expenses, net 15 16 16 Write-offs, net (11 ) (17 ) (17 ) Ending balance $ 16 $ 12 $ 13
Derivatives [Policy Text Block]	Derivatives Nevada Power employs a number of different derivative contracts, which may include forwards, futures, options, swaps and other agreements, to manage its commodity price and interest rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked‑to‑market and settled amounts are recognized as cost of fuel, energy and capacity on the Consolidated Statements of Operations. For Nevada Power 's derivative contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For a derivative contract not probable of inclusion in rates, changes in the fair value are recognized in earnings.
Inventories [Policy Text Block]	Inventories Inventories consist mainly of materials and supplies totaling $56 million and $60 million as of December 31 , 2017 and 2016 , respectively, and fuel, which includes coal stock, stored natural gas and fuel oil, totaling $3 million and $13 million as of December 31 , 2017 and 2016 , respectively. The cost is determined using the average cost method. Materials are charged to inventory when purchased and are expensed or capitalized to construction work in process, as appropriate, when used. Fuel costs are recovered from retail customers through the base tariff energy rates and deferred energy accounting adjustment charges approved by the Public Utilities Commission of Nevada ("PUCN").
Property, plant and equipment, net - general [Policy Text Block]	Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. Nevada Power capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include debt allowance for funds used during construction ("AFUDC"), and equity AFUDC, as applicable. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. The cost of repairs and minor replacements are charged to expense when incurred with the exception of costs for generation plant maintenance under certain long-term service agreements. Costs under these agreements are expensed straight-line over the term of the agreements as approved by the PUCN. Depreciation and amortization are generally computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by Nevada Power 's various regulatory authorities. Depreciation studies are completed by Nevada Power to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as a non-current regulatory liability on the Consolidated Balance Sheets. As actual removal costs are incurred, the associated liability is reduced. Generally when Nevada Power retires or sells a component of regulated property, plant and equipment depreciated using the composite method, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings with the exception of material gains or losses on regulated property, plant and equipment depreciated on a straight-line basis, which is then recorded to a regulatory asset or liability. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of regulated facilities, are capitalized as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. The rate applied to construction costs is the lower of the PUCN allowed rate of return and rates computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC"). After construction is completed, Nevada Power is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets. Nevada Power 's AFUDC rate used during 2017 and 2016 was 8.09% .
Property, plant and equipment, net - asset retirement obligations [Policy Text Block]	Asset Retirement Obligations Nevada Power recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. Nevada Power 's AROs are primarily associated with its generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability on the Consolidated Balance Sheets. The costs are not recovered in rates until the work has been completed.
Property, plant and equipment, net - impairment [Policy Text Block]	Impairment of Long-Lived Assets Nevada Power evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. As substantially all property, plant and equipment was used in regulated businesses as of December 31 , 2017 , the impacts of regulation are considered when evaluating the carrying value of regulated assets.
Revenue recognition [Policy Text Block]	Revenue Recognition Revenue is recognized as electricity is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31 , 2017 and 2016 , unbilled revenue was $111 million and $91 million , respectively, and is included in accounts receivable, net on the Consolidated Balance Sheets. Rates are established by regulators or contractual arrangements. When preliminary rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. Nevada Power records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations. Nevada Power primarily buys energy and natural gas to satisfy its customer load requirements. Due to changes in retail customer load requirements, Nevada Power may not take physical delivery of the energy or natural gas. Nevada Power may sell the excess energy or natural gas to the wholesale market. In such instances, it is Nevada Power 's policy to record such sales net in cost of fuel, energy and capacity.
Unamortized debt premiums, discounts and financing costs [Policy Text Block]	Unamortized Debt Premiums, Discounts and Issuance Costs Premiums, discounts and financing costs incurred for the issuance of long-term debt are amortized over the term of the related financing on a straight-line basis.
Income taxes [Policy Text Block]	Income Taxes Berkshire Hathaway includes Nevada Power in its consolidated United States federal income tax return. Consistent with established regulatory practice, Nevada Power 's provision for income taxes has been computed on a separate return basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of other comprehensive income ("OCI") are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property‑related basis differences and other various differences that Nevada Power deems probable to be passed on to its customers are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties.
Income tax uncertainties [Policy Text Block]	In determining Nevada Power 's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by Nevada Power 's various regulatory jurisdictions. Nevada Power 's income tax returns are subject to continuous examinations by federal, state and local income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. Nevada Power recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of Nevada Power 's federal, state and local income tax examinations is uncertain, Nevada Power believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on Nevada Power 's consolidated financial results. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations.
Segment reporting	Segment Information Nevada Power currently has one segment, which includes its regulated electric utility operations.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. Nevada Power plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Nevada Power adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when Nevada Power has the right to invoice as it corresponds directly with the value to the customer of Nevada Power's performance to date. Nevada Power's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by customer class.
Sierra Pacific Power Company [Member]
Allowance for Doubtful Accounts [Line Items]
Basis of consolidation and presentation [Policy Text Block]	Basis of Consolidation and Presentation The Consolidated Financial Statements include the accounts of Sierra Pacific and its subsidiaries in which it holds a controlling financial interest as of the financial statement date. Intercompany accounts and transactions have been eliminated. The Consolidated Statements of Comprehensive Income have been omitted as net income equals comprehensive income for the years ended December 31, 2017 , 2016 and 2015 . Certain amounts in the prior period Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported operating income, net income or retained earnings.
Use of estimates in preparation of financial statements [Policy Text Block]	Use of Estimates in Preparation of Financial Statements The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. These estimates include, but are not limited to, the effects of regulation; recovery of long-lived assets; certain assumptions made in accounting for pension and other postretirement benefits; asset retirement obligations ("AROs"); income taxes; unbilled revenue; valuation of certain financial assets and liabilities, including derivative contracts; and accounting for contingencies. Actual results may differ from the estimates used in preparing the Consolidated Financial Statements.
Accounting for the effects of certain types of regulation [Policy Text Block]	Accounting for the Effects of Certain Types of Regulation Sierra Pacific prepares its Consolidated Financial Statements in accordance with authoritative guidance for regulated operations, which recognizes the economic effects of regulation. Accordingly, Sierra Pacific defers the recognition of certain costs or income if it is probable that, through the ratemaking process, there will be a corresponding increase or decrease in future regulated rates. Regulatory assets and liabilities are established to reflect the impacts of these deferrals, which will be recognized in earnings in the periods the corresponding changes in regulated rates occur. Sierra Pacific continually evaluates the applicability of the guidance for regulated operations and whether its regulatory assets and liabilities are probable of inclusion in future regulated rates by considering factors such as a change in the regulator's approach to setting rates from cost-based ratemaking to another form of regulation, other regulatory actions or the impact of competition that could limit Sierra Pacific 's ability to recover its costs. Sierra Pacific believes the application of the guidance for regulated operations is appropriate and its existing regulatory assets and liabilities are probable of inclusion in future regulated rates. The evaluation reflects the current political and regulatory climate at both the federal and state levels. If it becomes no longer probable that the deferred costs or income will be included in future regulated rates, the related regulatory assets and liabilities will be written off to net income, returned to customers or re-established as accumulated other comprehensive income (loss).
Fair value measurement [Policy Text Block]	Fair Value Measurements As defined under GAAP, fair value is the price that would be received to sell an asset or paid to transfer a liability between market participants in the principal market or in the most advantageous market when no principal market exists. Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. Different valuation techniques may be appropriate under the circumstances to determine the value that would be received to sell an asset or paid to transfer a liability in an orderly transaction. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not under duress. Nonperformance or credit risk is considered in determining fair value. Considerable judgment may be required in interpreting market data used to develop the estimates of fair value. Accordingly, estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized in a current or future market exchange.
Cash equivalent and restricted cash and investments [Policy Text Block]	Cash Equivalents and Restricted Cash and Investments Cash equivalents consist of funds invested in money market mutual funds, United States Treasury Bills and other investments with a maturity of three months or less when purchased. Cash and cash equivalents exclude amounts where availability is restricted by legal requirements, loan agreements or other contractual provisions. Restricted amounts are included in other assets and other current assets on the Consolidated Balance Sheets.
Allowance for doubtful accounts [Policy Text Block]	Allowance for Doubtful Accounts Accounts receivable are stated at the outstanding principal amount, net of an estimated allowance for doubtful accounts. The allowance for doubtful accounts is based on Sierra Pacific 's assessment of the collectibility of amounts owed to Sierra Pacific by its customers. This assessment requires judgment regarding the ability of customers to pay or the outcome of any pending disputes. Sierra Pacific also has the ability to assess deposits on customers who have delayed payments or who are deemed to be a credit risk. The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 2 $ 1 $ 2 Charged to operating costs and expenses, net 2 2 1 Write-offs, net (2 ) (1 ) (2 ) Ending balance $ 2 $ 2 $ 1
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 2 $ 1 $ 2 Charged to operating costs and expenses, net 2 2 1 Write-offs, net (2 ) (1 ) (2 ) Ending balance $ 2 $ 2 $ 1
Derivatives [Policy Text Block]	Derivatives Sierra Pacific employs a number of different derivative contracts, which may include forwards, futures, options, swaps and other agreements, to manage its commodity price and interest rate risk. Derivative contracts are recorded on the Consolidated Balance Sheets as either assets or liabilities and are stated at estimated fair value unless they are designated as normal purchases or normal sales and qualify for the exception afforded by GAAP. Derivative balances reflect offsetting permitted under master netting agreements with counterparties and cash collateral paid or received under such agreements. Commodity derivatives used in normal business operations that are settled by physical delivery, among other criteria, are eligible for and may be designated as normal purchases or normal sales. Normal purchases or normal sales contracts are not marked‑to‑market and settled amounts are recognized as cost of fuel, energy and capacity or natural gas purchased for resale on the Consolidated Statements of Operations. For Sierra Pacific 's derivative contracts, the settled amount is generally included in regulated rates. Accordingly, the net unrealized gains and losses associated with interim price movements on contracts that are accounted for as derivatives and probable of inclusion in regulated rates are recorded as regulatory assets and liabilities. For a derivative contract not probable of inclusion in rates, changes in the fair value are recognized in earnings.
Inventories [Policy Text Block]	Inventories Inventories consist mainly of materials and supplies totaling $42 million and $36 million as of December 31 , 2017 and 2016 , respectively, and fuel, which includes coal stock, stored natural gas and fuel oil, totaling $7 million and $9 million as of December 31 , 2017 and 2016 , respectively. The cost is determined using the average cost method. Materials are charged to inventory when purchased and are expensed or capitalized to construction work in process, as appropriate, when used. Fuel costs are recovered from retail customers through the base tariff energy rates and deferred energy accounting adjustment charges approved by the Public Utilities Commission of Nevada ("PUCN").
Property, plant and equipment, net - general [Policy Text Block]	Property, Plant and Equipment, Net General Additions to property, plant and equipment are recorded at cost. Sierra Pacific capitalizes all construction-related material, direct labor and contract services, as well as indirect construction costs. Indirect construction costs include debt allowance for funds used during construction ("AFUDC"), and equity AFUDC, as applicable. The cost of additions and betterments are capitalized, while costs incurred that do not improve or extend the useful lives of the related assets are generally expensed. The cost of repairs and minor replacements are charged to expense when incurred with the exception of costs for generation plant maintenance under certain long-term service agreements. Costs under these agreements are expensed straight-line over the term of the agreements as approved by the PUCN. Depreciation and amortization are generally computed by applying the composite or straight-line method based on either estimated useful lives or mandated recovery periods as prescribed by Sierra Pacific 's various regulatory authorities. Depreciation studies are completed by Sierra Pacific to determine the appropriate group lives, net salvage and group depreciation rates. These studies are reviewed and rates are ultimately approved by the applicable regulatory commission. Net salvage includes the estimated future residual values of the assets and any estimated removal costs recovered through approved depreciation rates. Estimated removal costs are recorded as a non-current regulatory liability on the Consolidated Balance Sheets. As actual removal costs are incurred, the associated liability is reduced. Generally when Sierra Pacific retires or sells a component of regulated property, plant and equipment depreciated using the composite method, it charges the original cost, net of any proceeds from the disposition, to accumulated depreciation. Any gain or loss on disposals of all other assets is recorded through earnings with the exception of material gains or losses on regulated property, plant and equipment depreciated on a straight-line basis, which is then recorded to a regulatory asset or liability. Debt and equity AFUDC, which represent the estimated costs of debt and equity funds necessary to finance the construction of regulated facilities, are capitalized as a component of property, plant and equipment, with offsetting credits to the Consolidated Statements of Operations. The rate applied to construction costs is the lower of the PUCN allowed rate of return and rates computed based on guidelines set forth by the Federal Energy Regulatory Commission ("FERC"). After construction is completed, Sierra Pacific is permitted to earn a return on these costs as a component of the related assets, as well as recover these costs through depreciation expense over the useful lives of the related assets. Sierra Pacific 's AFUDC rate used during 2017 and 2016 was 6.65% and 7.62% for electric, 5.63% and 6.02% for natural gas, and 6.55% and 7.44% for common facilities, respectively.
Property, plant and equipment, net - asset retirement obligations [Policy Text Block]	Asset Retirement Obligations Sierra Pacific recognizes AROs when it has a legal obligation to perform decommissioning, reclamation or removal activities upon retirement of an asset. Sierra Pacific 's AROs are primarily associated with its generating facilities. The fair value of an ARO liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made, and is added to the carrying amount of the associated asset, which is then depreciated over the remaining useful life of the asset. Subsequent to the initial recognition, the ARO liability is adjusted for any revisions to the original estimate of undiscounted cash flows (with corresponding adjustments to property, plant and equipment, net) and for accretion of the ARO liability due to the passage of time. The difference between the ARO liability, the corresponding ARO asset included in property, plant and equipment, net and amounts recovered in rates to satisfy such liabilities is recorded as a regulatory asset or liability on the Consolidated Balance Sheets. The costs are not recovered in rates until the work has been completed.
Property, plant and equipment, net - impairment [Policy Text Block]	Impairment of Long-Lived Assets Sierra Pacific evaluates long-lived assets for impairment, including property, plant and equipment, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable or the assets are being held for sale. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value and any resulting impairment loss is reflected on the Consolidated Statements of Operations. As substantially all property, plant and equipment was used in regulated businesses as of December 31 , 2017 , the impacts of regulation are considered when evaluating the carrying value of regulated assets.
Revenue recognition [Policy Text Block]	Revenue Recognition Revenue is recognized as electricity or natural gas is delivered or services are provided. Revenue recognized includes billed and unbilled amounts. As of December 31 , 2017 and 2016 , unbilled revenue was $62 million and $52 million , respectively, and is included in accounts receivable, net on the Consolidated Balance Sheets. Rates are established by regulators or contractual arrangements. When preliminary rates are permitted to be billed prior to final approval by the applicable regulator, certain revenue collected may be subject to refund and a liability for estimated refunds is accrued. Sierra Pacific records sales, franchise and excise taxes collected directly from customers and remitted directly to the taxing authorities on a net basis on the Consolidated Statements of Operations. Sierra Pacific primarily buys energy and natural gas to satisfy its customer load requirements. Due to changes in retail customer load requirements, Sierra Pacific may not take physical delivery of the energy or natural gas. Sierra Pacific may sell the excess energy or natural gas to the wholesale market. In such instances, it is Sierra Pacific 's policy to allocate the natural gas sales between generation and natural gas retail based on usage. The energy sales and natural gas sales allocated to generation are recorded net in cost of fuel, energy and capacity. The natural gas sales allocated to natural gas retail is recorded as wholesale revenue.
Unamortized debt premiums, discounts and financing costs [Policy Text Block]	Unamortized Debt Premiums, Discounts and Issuance Costs Premiums, discounts and financing costs incurred for the issuance of long-term debt are amortized over the term of the related financing on a straight-line basis.
Income taxes [Policy Text Block]	Income Taxes Berkshire Hathaway includes Sierra Pacific in its consolidated United States federal income tax return. Consistent with established regulatory practice, Sierra Pacific 's provision for income taxes has been computed on a separate return basis. Deferred income tax assets and liabilities are based on differences between the financial statement and income tax basis of assets and liabilities using estimated income tax rates expected to be in effect for the year in which the differences are expected to reverse. Changes in deferred income tax assets and liabilities that are associated with components of other comprehensive income ("OCI") are charged or credited directly to OCI. On December 22, 2017, the Tax Cuts and Jobs Act ("2017 Tax Reform") was signed into law which, among other items, reduces the federal corporate tax rate from 35% to 21% . Changes in deferred income tax assets and liabilities that are associated with income tax benefits and expense for the federal tax rate change from 35% to 21%, certain property-related basis differences and other various differences that Sierra Pacific deems probable to be passed on to its customers are charged or credited directly to a regulatory asset or liability and will be included in regulated rates when the temporary differences reverse. Other changes in deferred income tax assets and liabilities are included as a component of income tax expense. Changes in deferred income tax assets and liabilities attributable to changes in enacted income tax rates are charged or credited to income tax expense or a regulatory asset or liability in the period of enactment. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount that is more-likely-than-not to be realized. Investment tax credits are generally deferred and amortized over the estimated useful lives of the related properties.
Income tax uncertainties [Policy Text Block]	In determining Sierra Pacific 's income taxes, management is required to interpret complex income tax laws and regulations, which includes consideration of regulatory implications imposed by Sierra Pacific 's various regulatory jurisdictions. Sierra Pacific 's income tax returns are subject to continuous examinations by federal, state and local income tax authorities that may give rise to different interpretations of these complex laws and regulations. Due to the nature of the examination process, it generally takes years before these examinations are completed and these matters are resolved. Sierra Pacific recognizes the tax benefit from an uncertain tax position only if it is more-likely-than-not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the Consolidated Financial Statements from such a position are measured based on the largest benefit that is more-likely-than-not to be realized upon ultimate settlement. Although the ultimate resolution of Sierra Pacific 's federal, state and local income tax examinations is uncertain, Sierra Pacific believes it has made adequate provisions for these income tax positions. The aggregate amount of any additional income tax liabilities that may result from these examinations, if any, is not expected to have a material impact on Sierra Pacific 's consolidated financial results. Estimated interest and penalties, if any, related to uncertain tax positions are included as a component of income tax expense on the Consolidated Statements of Operations.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. Sierra Pacific plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Sierra Pacific adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when Sierra Pacific has the right to invoice as it corresponds directly with the value to the customer of Sierra Pacific's performance to date. Sierra Pacific's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by segment and customer class.

Summary of Significant Accoun42

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2018-02, which amends FASB Accounting Standards Codification ("ASC") Topic 220, "Income Statement - Reporting Comprehensive Income." The amendments in this guidance require a reclassification from accumulated other comprehensive income to retained earnings for the stranded tax effects that were created from the enactment of the 2017 Tax Reform. The reclassification is the difference between the historical income tax rates and the enacted rate for the items previously recorded in accumulated other comprehensive income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted retrospectively to each period(s) in which the effect of the change in the 2017 Tax Reform is recognized. Considering the significant components of the Company's accumulated other comprehensive income relate to (a) unrecognized amounts on retirement benefits of foreign pension plans and (b) unrealized gains on available-for-sale securities, which were reclassified as required by ASU No. 2016-01 that was adopted on January 1, 2018, the adoption of ASU No. 2018-02 will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2017, the FASB issued ASU No. 2017-12, which amends FASB ASC Topic 815, "Derivatives and Hedging." The amendments in this guidance update the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements, expands an entity's ability to hedge non-financial and financial risk components and reduces complexity in fair value hedges of interest rate risk. In addition, it eliminates the requirement to separately measure and report hedge ineffectiveness and generally requires the entire change in fair value of a hedging instrument to be presented in the same income statement line as the hedged item and also eases certain documentation and assessment requirements. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach by means of a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The Company is currently evaluating the impact of adopting this guidance on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In March 2017, the FASB issued ASU No. 2017-07, which amends FASB ASC Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, “Statement of Cash Flows - Overall.” The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. The Company adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. The Company plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The Company adopted this guidance effective January 1, 2018 with a cumulative-effect increase to retained earnings of $1,085 million and a corresponding decrease to AOCI. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. The Company adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when the Company has the right to invoice as it corresponds directly with the value to the customer of the Company's performance to date. The Company's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by regulated energy, nonregulated energy and real estate, with further disaggregation of regulated energy by customer class and line of business and real estate by line of business.
PacifiCorp [Member]
Accounting Policies [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. PacifiCorp adopted this guidance January 1, 2018 and the adoption of this guidance will not have a material impact on the Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. PacifiCorp plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. PacifiCorp adopted this guidance on January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. PacifiCorp adopted this guidance on January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when PacifiCorp has the right to invoice as it corresponds directly with the value to the customer of PacifiCorp's performance to date. PacifiCorp plans to quantitatively disaggregate revenue in the required financial statement footnote by customer class.
Allowance for Doubtful Accounts [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility Plant: Generation 14 - 67 years $ 12,490 $ 12,371 Transmission 58 - 75 years 6,226 6,055 Distribution 20 - 70 years 6,792 6,590 Intangible plant (1) 5 - 62 years 937 884 Other 5 - 60 years 1,435 1,384 Utility plant in service 27,880 27,284 Accumulated depreciation and amortization (9,366 ) (8,790 ) Utility plant in service, net 18,514 18,494 Other non-regulated, net of accumulated depreciation and amortization 45 years 11 11 Plant, net 18,525 18,505 Construction work-in-progress 678 657 Property, plant and equipment, net $ 19,203 $ 19,162 (1) Computer software costs included in intangible plant are initially assigned a depreciable life of 5 to 10 years.
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 7 $ 7 $ 7 Charged to operating costs and expenses, net 15 12 10 Write-offs, net (12 ) (12 ) (10 ) Ending balance $ 10 $ 7 $ 7
MidAmerican Energy Company [Member]
Accounting Policies [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, “Statement of Cash Flows - Overall.” The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively, wherein the statement of cash flows of each period presented should be adjusted to reflect the new guidance. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. MidAmerican Energy plans to adopt this guidance effective January 1, 2019, and is currently evaluating the impact on its Financial Statements and disclosures included within Notes to Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, which amends FASB ASC Subtopic 825-10, "Financial Instruments - Overall." The amendments in this guidance address certain aspects of recognition, measurement, presentation and disclosure of financial instruments including a requirement that all investments in equity securities that do not qualify for equity method accounting or result in consolidation of the investee be measured at fair value with changes in fair value recognized in net income. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption not permitted, and is required to be adopted prospectively by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. MidAmerican Energy adopted this guidance effective January 1, 2018, and the adoption will not have a material impact on its Financial Statements and disclosures included within Notes to Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No.2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. MidAmerican Energy adopted this guidance effective January 1, 2018, under the modified retrospective method and the adoption will not have an impact on its Financial Statements but will increase the disclosures included within Notes to Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized equal to what MidAmerican Energy has the right to invoice as it corresponds directly with the value to the customer of MidAmerican Energy's performance to date. MidAmerican Energy's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by customer class for each segment.
Allowance for Doubtful Accounts [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant in service: Generation 20-70 years $ 12,107 $ 11,282 Transmission 52-75 years 1,838 1,726 Electric distribution 20-75 years 3,380 3,197 Gas distribution 29-75 years 1,640 1,565 Utility plant in service 18,965 17,770 Accumulated depreciation and amortization (5,561 ) (5,448 ) Utility plant in service, net 13,404 12,322 Nonregulated property, net: Nonregulated property gross 20-50 years 7 7 Accumulated depreciation and amortization (1 ) (1 ) Nonregulated property, net 6 6 13,410 12,328 Construction work-in-progress 797 493 Property, plant and equipment, net $ 14,207 $ 12,821
Nevada Power Company [Member]
Accounting Policies [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Nevada Power adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. Nevada Power plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Nevada Power adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when Nevada Power has the right to invoice as it corresponds directly with the value to the customer of Nevada Power's performance to date. Nevada Power's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by customer class.
Allowance for Doubtful Accounts [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant: Generation 30 - 55 years $ 3,707 $ 4,271 Distribution 20 - 65 years 3,314 3,231 Transmission 45 - 65 years 1,860 1,846 General and intangible plant 5 - 65 years 793 738 Utility plant 9,674 10,086 Accumulated depreciation and amortization (2,871 ) (3,205 ) Utility plant, net 6,803 6,881 Other non-regulated, net of accumulated depreciation and amortization 45 years 1 2 Plant, net 6,804 6,883 Construction work-in-progress 73 114 Property, plant and equipment, net $ 6,877 $ 6,997
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 12 $ 13 $ 14 Charged to operating costs and expenses, net 15 16 16 Write-offs, net (11 ) (17 ) (17 ) Ending balance $ 16 $ 12 $ 13
Sierra Pacific Power Company [Member]
Accounting Policies [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements In March 2017, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2017-07, which amends FASB Accounting Standards Codification ("ASC") Topic 715, "Compensation - Retirement Benefits." The amendments in this guidance require that an employer disaggregate the service cost component from the other components of net benefit cost and report the service cost component in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the statement of operations separately from the service cost component and outside the subtotal of operating income. Additionally, the guidance only allows the service cost component to be eligible for capitalization when applicable. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. This guidance must be adopted retrospectively for the presentation of the service cost component and the other components of net benefit cost in the statement of operations and prospectively for the capitalization of the service cost component in the balance sheet. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016-18, which amends FASB ASC Subtopic 230-10, "Statement of Cash Flows - Overall." The amendments in this guidance require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In August 2016, the FASB issued ASU No. 2016-15, which amends FASB ASC Topic 230, "Statement of Cash Flows." The amendments in this guidance address the classification of eight specific cash flow issues within the statement of cash flows with the objective of reducing the existing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted, and is required to be adopted retrospectively. Sierra Pacific adopted this guidance effective January 1, 2018 and the adoption will not have a material impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, which creates FASB ASC Topic 842, "Leases" and supersedes Topic 840 "Leases." This guidance increases transparency and comparability among entities by recording lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. A lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee have not significantly changed from previous guidance. In January 2018, the FASB issued ASU No. 2018-01 that provides for an optional transition practical expedient allowing companies to not have to evaluate existing land easements if they were not previously accounted for under ASC Topic 840, "Leases." This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted, and is required to be adopted using a modified retrospective approach. Sierra Pacific plans to adopt this guidance effective January 1, 2019 and is currently evaluating the impact on its Consolidated Financial Statements and disclosures included within Notes to Consolidated Financial Statements. In May 2014, the FASB issued ASU No. 2014-09, which creates FASB ASC Topic 606, "Revenue from Contracts with Customers" and supersedes ASC Topic 605, "Revenue Recognition." The guidance replaces industry-specific guidance and establishes a single five-step model to identify and recognize revenue. The core principle of the guidance is that an entity should recognize revenue upon transfer of control of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods or services. Additionally, the guidance requires the entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In August 2015, the FASB issued ASU No. 2015-14, which defers the effective date of ASU No. 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017. During 2016 and 2017, the FASB issued several ASUs that clarify the implementation guidance for ASU No. 2014-09 but do not change the core principle of the guidance. This guidance may be adopted retrospectively or under a modified retrospective method where the cumulative effect is recognized at the date of initial application. Sierra Pacific adopted this guidance effective January 1, 2018 under the modified retrospective method and the adoption will not have an impact on its Consolidated Financial Statements but will increase the disclosures included within Notes to Consolidated Financial Statements. The timing and amount of revenue recognized after adoption of the new guidance will not be different than before as a majority of revenue is recognized when Sierra Pacific has the right to invoice as it corresponds directly with the value to the customer of Sierra Pacific's performance to date. Sierra Pacific's current plan is to quantitatively disaggregate revenue in the required financial statement footnote by segment and customer class.
Allowance for Doubtful Accounts [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant: Electric generation 25 - 60 years $ 1,144 $ 1,137 Electric distribution 20 - 100 years 1,459 1,417 Electric transmission 50 - 100 years 786 771 Electric general and intangible plant 5 - 70 years 181 164 Natural gas distribution 35 - 70 years 390 381 Natural gas general and intangible plant 5 - 70 years 14 15 Common general 5 - 70 years 294 267 Utility plant 4,268 4,152 Accumulated depreciation and amortization (1,513 ) (1,442 ) Utility plant, net 2,755 2,710 Other non-regulated, net of accumulated depreciation and amortization 70 years 5 5 Plant, net 2,760 2,715 Construction work-in-progress 132 107 Property, plant and equipment, net $ 2,892 $ 2,822
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The change in the balance of the allowance for doubtful accounts, which is included in accounts receivable, net on the Consolidated Balance Sheets, is summarized as follows for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 2 $ 1 $ 2 Charged to operating costs and expenses, net 2 2 1 Write-offs, net (2 ) (1 ) (2 ) Ending balance $ 2 $ 2 $ 1

Property, Plant and Equipment43

Property, Plant and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Regulated assets: Utility generation, transmission and distribution systems 5-80 years $ 74,660 $ 71,536 Interstate natural gas pipeline assets 3-80 years 7,176 6,942 81,836 78,478 Accumulated depreciation and amortization (24,478 ) (23,603 ) Regulated assets, net 57,358 54,875 Nonregulated assets: Independent power plants 5-30 years 6,010 5,594 Other assets 3-30 years 1,489 1,002 7,499 6,596 Accumulated depreciation and amortization (1,542 ) (1,060 ) Nonregulated assets, net 5,957 5,536 Net operating assets 63,315 60,411 Construction work-in-progress 2,556 2,098 Property, plant and equipment, net $ 65,871 $ 62,509
MidAmerican Energy Company [Member]
Property, Plant and Equipment [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant in service: Generation 20-70 years $ 12,107 $ 11,282 Transmission 52-75 years 1,838 1,726 Electric distribution 20-75 years 3,380 3,197 Gas distribution 29-75 years 1,640 1,565 Utility plant in service 18,965 17,770 Accumulated depreciation and amortization (5,561 ) (5,448 ) Utility plant in service, net 13,404 12,322 Nonregulated property, net: Nonregulated property gross 20-50 years 7 7 Accumulated depreciation and amortization (1 ) (1 ) Nonregulated property, net 6 6 13,410 12,328 Construction work-in-progress 797 493 Property, plant and equipment, net $ 14,207 $ 12,821
Depreciation and Amortization Rates [Table Text Block]	The average depreciation and amortization rates applied to depreciable utility plant for the years ended December 31 were as follows: 2017 2016 2015 Electric 2.6 % 2.8 % 3.0 % Gas 2.7 % 2.9 % 2.9 %
PacifiCorp [Member]
Property, Plant and Equipment [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility Plant: Generation 14 - 67 years $ 12,490 $ 12,371 Transmission 58 - 75 years 6,226 6,055 Distribution 20 - 70 years 6,792 6,590 Intangible plant (1) 5 - 62 years 937 884 Other 5 - 60 years 1,435 1,384 Utility plant in service 27,880 27,284 Accumulated depreciation and amortization (9,366 ) (8,790 ) Utility plant in service, net 18,514 18,494 Other non-regulated, net of accumulated depreciation and amortization 45 years 11 11 Plant, net 18,525 18,505 Construction work-in-progress 678 657 Property, plant and equipment, net $ 19,203 $ 19,162 (1) Computer software costs included in intangible plant are initially assigned a depreciable life of 5 to 10 years.
Nevada Power Company [Member]
Property, Plant and Equipment [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant: Generation 30 - 55 years $ 3,707 $ 4,271 Distribution 20 - 65 years 3,314 3,231 Transmission 45 - 65 years 1,860 1,846 General and intangible plant 5 - 65 years 793 738 Utility plant 9,674 10,086 Accumulated depreciation and amortization (2,871 ) (3,205 ) Utility plant, net 6,803 6,881 Other non-regulated, net of accumulated depreciation and amortization 45 years 1 2 Plant, net 6,804 6,883 Construction work-in-progress 73 114 Property, plant and equipment, net $ 6,877 $ 6,997
Sierra Pacific Power Company [Member]
Property, Plant and Equipment [Line Items]
Public Utility Property, Plant, and Equipment (NPC, SPPC, PacifiCorp) [Table Text Block]	Property, plant and equipment, net consists of the following as of December 31 (in millions): Depreciable Life 2017 2016 Utility plant: Electric generation 25 - 60 years $ 1,144 $ 1,137 Electric distribution 20 - 100 years 1,459 1,417 Electric transmission 50 - 100 years 786 771 Electric general and intangible plant 5 - 70 years 181 164 Natural gas distribution 35 - 70 years 390 381 Natural gas general and intangible plant 5 - 70 years 14 15 Common general 5 - 70 years 294 267 Utility plant 4,268 4,152 Accumulated depreciation and amortization (1,513 ) (1,442 ) Utility plant, net 2,755 2,710 Other non-regulated, net of accumulated depreciation and amortization 70 years 5 5 Plant, net 2,760 2,715 Construction work-in-progress 132 107 Property, plant and equipment, net $ 2,892 $ 2,822

Jointly Owned Utility Facilit44

Jointly Owned Utility Facilities (Tables)	12 Months Ended
	Dec. 31, 2017
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Table Text Block]	The amounts shown in the table below represent the Company's share in each jointly owned facility included in property, plant and equipment, net as of December 31, 2017 (dollars in millions): Accumulated Construction Company Facility In Depreciation and Work-in- Share Service Amortization Progress PacifiCorp: Jim Bridger Nos. 1-4 67 % $ 1,442 $ 616 $ 12 Hunter No. 1 94 474 172 7 Hunter No. 2 60 297 106 1 Wyodak 80 469 216 1 Colstrip Nos. 3 and 4 10 247 131 4 Hermiston 50 180 81 1 Craig Nos. 1 and 2 19 365 231 3 Hayden No. 1 25 74 34 — Hayden No. 2 13 43 21 — Foote Creek 79 40 26 — Transmission and distribution facilities Various 794 238 67 Total PacifiCorp 4,425 1,872 96 MidAmerican Energy: Louisa No. 1 88 % 807 432 8 Quad Cities Nos. 1 and 2 (1) 25 698 387 20 Walter Scott, Jr. No. 3 79 617 316 8 Walter Scott, Jr. No. 4 (2) 60 456 112 1 George Neal No. 4 41 307 159 1 Ottumwa No. 1 52 567 206 40 George Neal No. 3 72 425 183 7 Transmission facilities Various 249 87 1 Total MidAmerican Energy 4,126 1,882 86 NV Energy: Navajo 11 % 220 152 — Valmy 50 388 233 1 Transmission facilities Various 206 45 — Total NV Energy 814 430 1 BHE Pipeline Group - common facilities Various 286 169 — Total $ 9,651 $ 4,353 $ 183 (1) Includes amounts related to nuclear fuel. (2) Facility in-service and accumulated depreciation and amortization amounts are net of credits applied under Iowa revenue sharing arrangements totaling $319 million and $81 million , respectively.
PacifiCorp [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Table Text Block]	The amounts shown in the table below represent PacifiCorp's share in each jointly owned facility included in property, plant and equipment, net as of December 31, 2017 (dollars in millions): Facility Accumulated Construction PacifiCorp in Depreciation and Work-in- Share Service Amortization Progress Jim Bridger Nos. 1 - 4 67 % $ 1,442 $ 616 $ 12 Hunter No. 1 94 474 172 7 Hunter No. 2 60 297 106 1 Wyodak 80 469 216 1 Colstrip Nos. 3 and 4 10 247 131 4 Hermiston 50 180 81 1 Craig Nos. 1 and 2 19 365 231 3 Hayden No. 1 25 74 34 — Hayden No. 2 13 43 21 — Foote Creek 79 40 26 — Transmission and distribution facilities Various 794 238 67 Total $ 4,425 $ 1,872 $ 96
MidAmerican Energy Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Table Text Block]	The amounts shown in the table below represent MidAmerican Energy's share in each jointly owned facility included in property, plant and equipment, net as of December 31, 2017 (dollars in millions): Accumulated Construction Company Plant in Depreciation and Work-in- Share Service Amortization Progress Louisa Unit No. 1 88 % $ 807 $ 432 $ 8 Quad Cities Unit Nos. 1 & 2 (1) 25 698 387 20 Walter Scott, Jr. Unit No. 3 79 617 316 8 Walter Scott, Jr. Unit No. 4 (2) 60 456 112 1 George Neal Unit No. 4 41 307 159 1 Ottumwa Unit No. 1 52 567 206 40 George Neal Unit No. 3 72 425 183 7 Transmission facilities Various 249 87 1 Total $ 4,126 $ 1,882 $ 86 (1) Includes amounts related to nuclear fuel. (2) Plant in service and accumulated depreciation and amortization amounts are net of credits applied under Iowa revenue sharing arrangements totaling $319 million and $81 million , respectively.
Nevada Power Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Table Text Block]	The amounts shown in the table below represent Nevada Power 's share in each jointly owned facility included in property, plant and equipment, net as of December 31 , 2017 (dollars in millions): Nevada Construction Power's Utility Accumulated Work-in- Share Plant Depreciation Progress Navajo Generating Station 11 % $ 220 $ 152 $ — ON Line Transmission Line 24 146 16 — Other transmission facilities Various 48 26 — Total $ 414 $ 194 $ —
Sierra Pacific Power Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Facilities [Table Text Block]	The amounts shown in the table below represent Sierra Pacific 's share in each jointly owned facility included in property, plant and equipment, net as of December 31 , 2017 (dollars in millions): Sierra Construction Pacific's Utility Accumulated Work-in- Share Plant Depreciation Progress Valmy Generating Station 50 % $ 388 $ 233 $ 1 ON Line Transmission Line 1 8 1 — Valmy Transmission 50 4 2 — Total $ 400 $ 236 $ 1

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets [Table Text Block]	Regulatory assets represent costs that are expected to be recovered in future regulated rates. The Company's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Employee benefit plans (1) 16 years $ 675 $ 816 Asset disposition costs Various 387 281 Asset retirement obligations 13 years 334 301 Abandoned projects 3 years 156 159 Deferred operating costs 13 years 147 97 Deferred income taxes (2) Various 143 1,754 Unrealized loss on regulated derivative contracts 4 years 122 154 Unamortized contract values 6 years 89 98 Deferred net power costs 2 years 58 38 Other Various 839 759 Total regulatory assets $ 2,950 $ 4,457 Reflected as: Current assets $ 189 $ 150 Noncurrent assets 2,761 4,307 Total regulatory assets $ 2,950 $ 4,457 (1) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized. (2) Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
Regulatory Liabilities [Table Text Block]	Regulatory liabilities represent income to be recognized or amounts to be returned to customers in future periods. The Company's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) Various $ 4,143 $ 25 Cost of removal (2) 27 years 2,349 2,242 Levelized depreciation 22 years 332 244 Asset retirement obligations 35 years 177 122 Impact fees 6 years 89 90 Employee benefit plans (3) 11 years 69 25 Deferred net power costs 2 years 8 64 Unrealized gain on regulated derivative contracts 1 year 3 6 Other Various 341 302 Total regulatory liabilities $ 7,511 $ 3,120 Reflected as: Current liabilities $ 202 $ 187 Noncurrent liabilities 7,309 2,933 Total regulatory liabilities $ 7,511 $ 3,120 (1) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts. (2) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost. (3) Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized.
PacifiCorp [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets [Table Text Block]	Regulatory assets represent costs that are expected to be recovered in future rates. PacifiCorp's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) N/A $ — $ 421 Employee benefit plans (2) 20 years 418 525 Utah mine disposition (3) Various 156 166 Unamortized contract values 6 years 89 98 Deferred net power costs 1 year 21 33 Unrealized loss on derivative contracts 4 years 101 73 Asset retirement obligation 22 years 100 82 Other Various 176 145 Total regulatory assets $ 1,061 $ 1,543 Reflected as: Current assets $ 31 $ 53 Noncurrent assets 1,030 1,490 Total regulatory assets $ 1,061 $ 1,543 (1) Amount primarily represents income tax benefits and expense related to certain property-related basis differences and other various items that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. (2) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in rates when recognized. (3) Amounts represent regulatory assets established as a result of the Utah mine disposition in 2015 for the net property, plant and equipment not considered probable of disallowance and for the portion of losses associated with the assets held for sale, UMWA 1974 Pension Plan withdrawal and closure costs incurred to date considered probable of recove
Regulatory Liabilities [Table Text Block]	es Regulatory liabilities represent income to be recognized or amounts to be returned to customers in future periods. PacifiCorp's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Cost of removal (1) 26 years $ 955 $ 917 Deferred income taxes (2) Various 1,960 9 Other Various 156 106 Total regulatory liabilities $ 3,071 $ 1,032 Reflected as: Current liabilities $ 75 $ 54 Noncurrent liabilities 2,996 978 Total regulatory liabilities $ 3,071 $ 1,032 (1) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying c
MidAmerican Energy Company [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets [Table Text Block]	Regulatory assets represent costs that are expected to be recovered in future regulated rates. MidAmerican Energy's regulatory assets reflected on the Balance Sheets consist of the following as of December 31 (in millions): Average Remaining Life 2017 2016 Deferred income taxes, net (1) N/A $ — $ 985 Asset retirement obligations (2) 10 years 133 105 Employee benefit plans (3) 13 years 38 40 Unrealized loss on regulated derivative contracts 1 year 6 2 Other Various 27 29 Total $ 204 $ 1,161 (1) Amounts primarily represent income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. (2) Amount predominantly relates to asset retirement obligations for fossil-fueled and wind-powered generating facilities. Refer to Note 12 for a discussion of asset retirement obligations. (3) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.
Regulatory Liabilities [Table Text Block]	Regulatory liabilities represent income to be recognized or amounts to be returned to customers in future periods. MidAmerican Energy's regulatory liabilities reflected on the Balance Sheets consist of the following as of December 31 (in millions): Average Remaining Life 2017 2016 Cost of removal accrual (1) 28 years $ 688 $ 665 Deferred income taxes (2) 28 years 681 — Asset retirement obligations (3) 35 years 173 117 Employee benefit plans (4) 11 years 41 12 Pre-funded AFUDC on transmission MVPs (5) 55 years 35 35 Iowa electric revenue sharing accrual (6) 1 year 26 30 Unrealized gain on regulated derivative contracts 1 year 3 6 Other Various 14 18 Total $ 1,661 $ 883 (1) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing utility plant in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost. (2) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts. (3) Amount predominantly represents the excess of nuclear decommission trust assets over the related asset retirement obligation. Refer to Note 12 for a discussion of asset retirement obligations. (4) Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized. (5) Represents AFUDC accrued on transmission MVPs that is deducted from rate base as a result of the inclusion of related construction work-in-progress in rate base. (6) Represents current-year accruals under a regulatory arrangement in Iowa in which equity returns exceeding specified thresholds reduce utility plant upon final determination.
Nevada Power Company [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets [Table Text Block]	Regulatory assets represent costs that are expected to be recovered in future rates. Nevada Power 's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Decommissioning costs 6 years $ 231 $ 114 Deferred operating costs 12 years 169 127 Merger costs from 1999 merger 27 years 130 136 Employee benefit plans (1) 8 years 89 105 Asset retirement obligations 7 years 72 74 Abandoned projects 3 years 58 75 Legacy meters 15 years 56 60 ON Line deferrals 36 years 47 44 Deferred energy costs 2 years 46 46 Deferred income taxes (2) N/A — 141 Other Various 71 98 Total regulatory assets $ 969 $ 1,020 Reflected as: Current assets $ 28 $ 20 Other assets 941 1,000 Total regulatory assets $ 969 $ 1,020 (1) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized. (2) Amounts primarily represent income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
Regulatory Liabilities [Table Text Block]	Regulatory liabilities represent amounts to be returned to customers in future periods. Nevada Power 's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) 33 years $ 670 $ 9 Cost of removal (2) 31 years 307 294 Impact fees 6 years 89 90 Energy efficiency program 1 year 27 37 Other Various 28 23 Total regulatory liabilities $ 1,121 $ 453 Reflected as: Current liabilities $ 91 $ 37 Other long-term liabilities 1,030 416 Total regulatory liabilities $ 1,121 $ 453 (1) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts. (2) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.
Sierra Pacific Power Company [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets [Table Text Block]	Regulatory assets represent costs that are expected to be recovered in future rates. Sierra Pacific 's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Employee benefit plans (1) 8 years $ 110 $ 128 Merger costs from 1999 merger 29 years 77 80 Abandoned projects 7 years 34 39 Renewable energy programs 2 years 23 25 Losses on reacquired debt 16 years 21 22 Deferred income taxes (2) N/A — 85 Other Various 67 56 Total regulatory assets $ 332 $ 435 Reflected as: Current assets $ 32 $ 25 Other assets 300 410 Total regulatory assets $ 332 $ 435 (1) Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized. (2) Amounts represent income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
Regulatory Liabilities [Table Text Block]	Regulatory liabilities represent amounts to be returned to customers in future periods. Sierra Pacific 's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions): Weighted Average Remaining Life 2017 2016 Deferred income taxes (1) 29 years $ 264 $ 6 Cost of removal (2) 41 years 211 205 Deferred energy costs 2 years 8 64 Other Various 17 15 Total regulatory liabilities $ 500 $ 290 Reflected as: Current liabilities $ 19 $ 69 Other long-term liabilities 481 221 Total regulatory liabilities $ 500 $ 290 (1) Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 9 for further discussion of 2017 Tax Reform impacts. (2) Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

Investments and Restricted Ca46

Investments and Restricted Cash and Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Investments and Restricted Cash and Investments [Table Text Block]	Investments and restricted cash and investments consists of the following as of December 31 (in millions): 2017 2016 Investments: BYD Company Limited common stock $ 1,961 $ 1,185 Rabbi trusts 441 403 Other 124 106 Total investments 2,526 1,694 Equity method investments: Tax equity investments 1,025 741 Electric Transmission Texas, LLC 524 672 Bridger Coal Company 137 165 Other 148 142 Total equity method investments 1,834 1,720 Restricted cash and investments: Quad Cities Station nuclear decommissioning trust funds 515 460 Other 348 282 Total restricted cash and investments 863 742 Total investments and restricted cash and investments $ 5,223 $ 4,156 Reflected as: Current assets $ 351 $ 211 Noncurrent assets 4,872 3,945 Total investments and restricted cash and investments $ 5,223 $ 4,156
MidAmerican Energy Company [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Investments and Restricted Cash and Investments [Table Text Block]	Investments and restricted cash and investments consists of the following amounts as of December 31 (in millions): 2017 2016 Nuclear decommissioning trust $ 515 $ 460 Rabbi trusts 198 184 Other 15 9 Total $ 728 $ 653

Short-Term Debt and Credit Fa47

Short-Term Debt and Credit Facilities (Tables)	12 Months Ended
	Dec. 31, 2017
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Short-Term Debt and Credit Facilities The following table summarizes BHE's and its subsidiaries' availability under their credit facilities as of December 31 (in millions): MidAmerican NV Northern BHE PacifiCorp Funding Energy Powergrid AltaLink Other Total (1) 2017: Credit facilities (2) $ 3,600 $ 1,000 $ 909 $ 650 $ 203 $ 1,054 $ 1,635 $ 9,051 Less: Short-term debt (3,331 ) (80 ) — — — (345 ) (732 ) (4,488 ) Tax-exempt bond support and letters of credit (7 ) (130 ) (370 ) (80 ) — (7 ) — (594 ) Net credit facilities $ 262 $ 790 $ 539 $ 570 $ 203 $ 702 $ 903 $ 3,969 2016: Credit facilities $ 2,000 $ 1,000 $ 609 $ 650 $ 185 $ 986 $ 915 $ 6,345 Less: Short-term debt (834 ) (270 ) (99 ) — — (289 ) (377 ) (1,869 ) Tax-exempt bond support and letters of credit (7 ) (142 ) (220 ) (80 ) — (8 ) — (457 ) Net credit facilities $ 1,159 $ 588 $ 290 $ 570 $ 185 $ 689 $ 538 $ 4,019 (1) The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method. (2) Includes amounts borrowed on a short-term loan totaling $600 million at BHE that was repaid in full in January 2018. As of December 31, 2017 , the Company was in compliance with the covenants of its credit facilities and letter of credit arrangements. BHE BHE has a $2.0 billion unsecured credit facility expiring in June 2020 with a one-year extension option subject to lender consent and a $1.0 billion unsecured credit facility expiring in May 2018 . These credit facilities, which are for general corporate purposes and also support BHE's commercial paper program and provide for the issuance of letters of credit, have variable interest rates based on the Eurodollar rate or a base rate, at BHE's option, plus a spread that varies based on BHE's credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 1.74% and 0.88% , respectively. These credit facilities require that BHE's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.70 to 1.0 as of the last day of each quarter. As of December 31, 2017 and 2016 , BHE had $96 million and $123 million , respectively, of letters of credit outstanding, of which $7 million as of December 31, 2017 and 2016 were issued under the credit facilities. These letters of credit primarily support power purchase agreements and debt service requirements at certain subsidiaries of BHE Renewables, LLC expiring through December 2018 and have provisions that automatically extend the annual expiration dates for an additional year unless the issuing bank elects not to renew a letter of credit prior to the expiration date. As of December 31, 2017, BHE had a $600 million term loan outstanding expiring in June 2018. The term loan had a variable interest rate based on the Eurodollar rate, plus a fixed spread, or a base rate, at BHE's option. In January 2018, BHE repaid the term loan at par plus accrued interest. As of December 31, 2017, the interest rate on the outstanding term loan was 2.27% . PacifiCorp PacifiCorp has a $600 million unsecured credit facility expiring in June 2020 with two one-year extension options subject to lender consent and a $400 million unsecured credit facility expiring in June 2020 with a one-year extension option subject to lender consent. These credit facilities, which support PacifiCorp's commercial paper program, certain series of its tax-exempt bond obligations and provide for the issuance of letters of credit, have variable interest rates based on the Eurodollar rate or a base rate, at PacifiCorp's option, plus a spread that varies based on PacifiCorp's credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 1.83% and 0.96% , respectively. These credit facilities require that PacifiCorp's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. As of December 31, 2017 and 2016 , PacifiCorp had $230 million and $269 million , respectively, of fully available letters of credit issued under committed arrangements. As of December 31, 2017 and 2016 , $216 million and $255 million , respectively, of these letters of credit support PacifiCorp's variable-rate tax-exempt bond obligations and expire through March 2019 and $14 million support certain transactions required by third parties and have provisions that automatically extend the annual expiration dates for an additional year unless the issuing bank elects not to renew a letter of credit prior to the expiration date. MidAmerican Funding MidAmerican Energy has a $900 million unsecured credit facility expiring in June 2020 with two one-year extension options subject to lender consent. The credit facility, which supports MidAmerican Energy's commercial paper program and its variable-rate tax-exempt bond obligations and provides for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at MidAmerican Energy's option, plus a spread that varies based on MidAmerican Energy's credit ratings for senior unsecured long-term debt securities. As of December 31, 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 0.73% . The credit facility requires that MidAmerican Energy's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. NV Energy Nevada Power has a $400 million secured credit facility expiring in June 2020 and Sierra Pacific has a $250 million secured credit facility expiring in June 2020 each w ith two one-year extension options subject to lender consent. These credit facilities, which are for general corporate purposes and provide for the issuance of letters of credit, have a variable interest rate based on the Eurodollar rate or a base rate, at each of the Nevada Utilities' option, plus a spread that varies based on each of the Nevada Utilities' credit ratings for its senior secured long‑term debt securities. Amounts due under each credit facility are collateralized by each of the Nevada Utilities' general and refunding mortgage bonds. These credit facilities require that each of the Nevada Utilities' ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. Northern Powergrid Northern Powergrid has a £150 million unsecured credit facility expiring in April 2020. The credit facility has a variable interest rate based on sterling London Interbank Offered Rate ("LIBOR") plus a spread that varies based on its credit ratings. The credit facility requires that the ratio of consolidated senior total net debt, including current maturities, to regulated asset value not exceed 0.8 to 1.0 at Northern Powergrid and 0.65 to 1.0 at Northern Powergrid (Northeast) Limited and Northern Powergrid (Yorkshire) plc as of June 30 and December 31. Northern Powergrid 's interest coverage ratio shall not be less than 2.5 to 1.0. AltaLink ALP has a C$750 million secured revolving credit facility expiring in December 2019 with a recurring one-year extension option subject to lender consent. The credit facility, which provides support for borrowings under the unsecured commercial paper program and may also be used for general corporate purposes, has a variable interest rate based on the Canadian bank prime lending rate or a spread above the Bankers' Acceptance rate, at ALP 's option, based on ALP 's credit ratings for its senior secured long-term debt securities. In addition, ALP has a C$75 million secured revolving credit facility expiring in December 2019 with a recurring one-year extension option subject to lender consent. The credit facility, which may be used for general corporate purposes and letters of credit, has a variable interest rate based on the Canadian bank prime lending rate, United States base rate, a spread above the United States LIBOR loan rate or a spread above the Bankers' Acceptance rate, at ALP 's option, based on ALP 's credit ratings for its senior secured long-term debt securities. At the renewal date, ALP has the option to convert these facilities to one-year term facilities. As of December 31, 2017 and 2016 , ALP had $121 million and $26 million outstanding under these facilities at a weighted average interest rate of 1.42% and 0.99% , respectively. The credit facilities require the consolidated indebtedness to total capitalization not exceed 0.75 to 1.0 measured as of the last day of each quarter. AltaLink Investments, L.P. has a C$300 million unsecured revolving term credit facility expiring in December 2022 and a C$200 million unsecured revolving credit facility expiring in December 2018 each with a recurring one-year extension option subject to lender consent. The credit facilities, which may be used for general corporate purposes and letters of credit to a maximum of C$10 million , have a variable interest rate based on the Canadian bank prime lending rate, United States base rate, a spread above the United States LIBOR loan rate or a spread above the Bankers' Acceptance rate, at AltaLink Investments, L.P.'s option, based on AltaLink Investments, L.P.'s credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , AltaLink Investments, L.P. had $224 million and $263 million outstanding under these facilities at a weighted average interest rate of 2.40% and 1.74% , respectively. The credit facilities require the consolidated total debt to capitalization to not exceed 0.8 to 1.0 and earnings before interest, taxes, depreciation and amortization to interest expense for the four fiscal quarters ended to not be less than 2.25 to 1.0 measured as of the last day of each quarter. HomeServices HomeServices has a $600 million unsecured credit facility expiring in September 2022. The credit facility, which is for general corporate purposes and provides for the issuance of letters of credit, has a variable interest rate based on the LIBOR or a base rate, at HomeServices' option, plus a spread that varies based on HomeServices' total net leverage ratio as of the last day of each quarter. As of December 31, 2017 and 2016 , HomeServices had $292 million and $50 million , respectively, outstanding under its credit facility with a weighted average interest rate of 2.75% and 1.77% , respectively. Through its subsidiaries, HomeServices maintains mortgage lines of credit totaling $1.0 billion and $565 million as of December 31, 2017 and 2016 , respectively, used for mortgage banking activities that expire beginning in January 2018 through December 2018 or are due on demand. The mortgage lines of credit have variable rates based on LIBOR plus a spread. Collateral for these credit facilities is comprised of residential property being financed and is equal to the loans funded with the facilities. As of December 31, 2017 and 2016 , HomeServices had $440 million and $327 million , respectively, outstanding under these mortgage lines of credit at a weighted average interest rate of 3.60% and 2.77% , respectively. BHE Renewables Letters of Credit In connection with their bond offerings, Topaz and Solar Star entered into separate letter of credit and reimbursement facilities totaling $435 million and $627 million as of December 31, 2017 and 2016 . Letters of credit issued under the letter of credit facilities will be used to (a) provide security under the power purchase agreement and large generator interconnection agreements, (b) fund the debt service reserve requirement and the operation and maintenance debt service reserve requirement and (c) provide security for remediation and mitigation liabilities. As of December 31, 2017 and 2016 , $357 million and $599 million , respectively, of letters of credit had been issued under these facilities. As of December 31, 2017 and 2016 , certain other renewable projects collectively have letters of credit outstanding of $118 million and $106 million , respectively, primarily in support of the power purchase agreements associated with the projects.
Short-Term Debt and Credit Facilities [Table Text Block]	The following table summarizes BHE's and its subsidiaries' availability under their credit facilities as of December 31 (in millions): MidAmerican NV Northern BHE PacifiCorp Funding Energy Powergrid AltaLink Other Total (1) 2017: Credit facilities (2) $ 3,600 $ 1,000 $ 909 $ 650 $ 203 $ 1,054 $ 1,635 $ 9,051 Less: Short-term debt (3,331 ) (80 ) — — — (345 ) (732 ) (4,488 ) Tax-exempt bond support and letters of credit (7 ) (130 ) (370 ) (80 ) — (7 ) — (594 ) Net credit facilities $ 262 $ 790 $ 539 $ 570 $ 203 $ 702 $ 903 $ 3,969 2016: Credit facilities $ 2,000 $ 1,000 $ 609 $ 650 $ 185 $ 986 $ 915 $ 6,345 Less: Short-term debt (834 ) (270 ) (99 ) — — (289 ) (377 ) (1,869 ) Tax-exempt bond support and letters of credit (7 ) (142 ) (220 ) (80 ) — (8 ) — (457 ) Net credit facilities $ 1,159 $ 588 $ 290 $ 570 $ 185 $ 689 $ 538 $ 4,019 (1) The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.
Sierra Pacific Power Company [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Credit Facility The following table summarizes Sierra Pacific's availability under its credit facilities as of December 31 (in millions): 2017 2016 Credit facilities $ 250 $ 250 Less - Water Facilities Refunding Revenue Bond support (80 ) (80 ) Net credit facilities $ 170 $ 170 Sierra Pacific has a $250 million secured credit facility expiring in June 2020 with two one-year extension options subject to lender consent. The credit facility, which is for general corporate purposes and provides for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at Sierra Pacific 's option, plus a spread that varies based on Sierra Pacific 's credit ratings for its senior secured long‑term debt securities. As of December 31 , 2017 and 2016 , Sierra Pacific had no borrowings outstanding under the credit facility. Amounts due under Sierra Pacific 's credit facility are collateralized by Sierra Pacific 's general and refunding mortgage bonds. The credit facility requires Sierra Pacific 's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter.
Short-Term Debt and Credit Facilities [Table Text Block]	The following table summarizes Sierra Pacific's availability under its credit facilities as of December 31 (in millions): 2017 2016 Credit facilities $ 250 $ 250 Less - Water Facilities Refunding Revenue Bond support (80 ) (80 ) Net credit facilities $ 170 $ 170
PacifiCorp [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Short-term Debt and Other Financing Agreements The following table summarizes PacifiCorp's availability under its credit facilities as of December 31 (in millions): 2017: Credit facilities $ 1,000 Less: Short-term debt (80 ) Tax-exempt bond support (130 ) Net credit facilities $ 790 2016: Credit facilities $ 1,000 Less: Short-term debt (270 ) Tax-exempt bond support (142 ) Net credit facilities $ 588 PacifiCorp has a $600 million unsecured credit facility expiring in June 2020 with two one-year extension options subject to lender consent and a $400 million unsecured credit facility expiring in June 2020 with a one-year extension option subject to lender consent. These credit facilities, which support PacifiCorp's commercial paper program, certain series of its tax-exempt bond obligations and provide for the issuance of letters of credit, have variable interest rates based on the Eurodollar rate or a base rate, at PacifiCorp's option, plus a spread that varies based on PacifiCorp's credit ratings for its senior unsecured long-term debt securities. As of December 31, 2017 and 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 1.83% and 0.96% , respectively. These credit facilities require that PacifiCorp's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter. As of December 31, 2017 and 2016 , PacifiCorp had $230 million and $269 million , respectively, of fully available letters of credit issued under committed arrangements. As of December 31, 2017 and 2016 , $216 million and $255 million , respectively, of these letters of credit, support PacifiCorp's variable-rate tax-exempt bond obligations and expire through March 2019 and $14 million support certain transactions required by third parties and have provisions that automatically extend the annual expiration dates for an additional year unless the issuing bank elects not to renew a letter of credit prior to the expiration date.
Short-Term Debt and Credit Facilities [Table Text Block]	The following table summarizes PacifiCorp's availability under its credit facilities as of December 31 (in millions): 2017: Credit facilities $ 1,000 Less: Short-term debt (80 ) Tax-exempt bond support (130 ) Net credit facilities $ 790 2016: Credit facilities $ 1,000 Less: Short-term debt (270 ) Tax-exempt bond support (142 ) Net credit facilities $ 588
MidAmerican Energy Company [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Short-Term Debt and Credit Facilities Interim financing of working capital needs and the construction program is obtained from unaffiliated parties through the sale of commercial paper or short-term borrowing from banks. MidAmerican Energy has a $900 million unsecured credit facility expiring June 2020 with two one-year extension options subject to lender consent. The credit facility, which supports MidAmerican Energy's commercial paper program and its variable-rate tax-exempt bond obligations and provides for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at MidAmerican Energy's option, plus a spread that varies based on MidAmerican Energy's credit ratings for senior unsecured long-term debt securities. In addition, MidAmerican Energy has a $5 million unsecured credit facility, which expires in June 2018 and has a variable interest rate based on LIBOR plus a spread. As of December 31, 2016 , the weighted average interest rate on commercial paper borrowings outstanding was 0.73% . The $900 million credit facility requires that MidAmerican Energy's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of any quarter. As of December 31, 2017 , MidAmerican Energy was in compliance with the covenants of its credit facilities. MidAmerican Energy has authority from the FERC to issue commercial paper and bank notes aggregating $905 million through February 28, 2019. The following table summarizes MidAmerican Energy's availability under its two unsecured revolving credit facilities as of December 31 (in millions): 2017 2016 Credit facilities $ 905 $ 605 Less: Short-term debt outstanding — (99 ) Variable-rate tax-exempt bond support (370 ) (220 ) Net credit facilities $ 535 $ 286
Short-Term Debt and Credit Facilities [Table Text Block]	The following table summarizes MidAmerican Energy's availability under its two unsecured revolving credit facilities as of December 31 (in millions): 2017 2016 Credit facilities $ 905 $ 605 Less: Short-term debt outstanding — (99 ) Variable-rate tax-exempt bond support (370 ) (220 ) Net credit facilities $ 535 $ 286
Nevada Power Company [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Credit Facility Nevada Power has a $400 million secured credit facility expiring in June 2020 w ith two one-year extension options subject to lender consent. The credit facility, which is for general corporate purposes and provide for the issuance of letters of credit, has a variable interest rate based on the Eurodollar rate or a base rate, at Nevada Power 's option, plus a spread that varies based on Nevada Power 's credit ratings for its senior secured long‑term debt securities. As of December 31 , 2017 and 2016 , Nevada Power had no borrowings outstanding under the credit facility. Amounts due under Nevada Power 's credit facility are collateralized by Nevada Power 's general and refunding mortgage bonds. The credit facility requires Nevada Power 's ratio of consolidated debt, including current maturities, to total capitalization not exceed 0.65 to 1.0 as of the last day of each quarter.

BHE Debt (Tables)

BHE Debt (Tables)	12 Months Ended
	Dec. 31, 2017
MEHC Debt [Abstract]
BHE Debt [Table Text Block]	Senior Debt BHE senior debt represents unsecured senior obligations of BHE that are redeemable in whole or in part at any time generally with make-whole premiums. BHE senior debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (in millions): Par Value 2017 2016 1.10% Senior Notes, due 2017 $ — $ — $ 400 5.75% Senior Notes, due 2018 650 650 649 2.00% Senior Notes, due 2018 350 350 349 2.40% Senior Notes, due 2020 350 349 349 3.75% Senior Notes, due 2023 500 498 497 3.50% Senior Notes, due 2025 400 398 397 8.48% Senior Notes, due 2028 301 302 477 6.125% Senior Bonds, due 2036 1,670 1,660 1,690 5.95% Senior Bonds, due 2037 550 547 547 6.50% Senior Bonds, due 2037 225 222 987 5.15% Senior Notes, due 2043 750 739 739 4.50% Senior Notes, due 2045 750 737 737 Total BHE Senior Debt $ 6,496 $ 6,452 $ 7,818 Reflected as: Current liabilities $ 1,000 $ 400 Noncurrent liabilities 5,452 7,418 Total BHE Senior Debt $ 6,452 $ 7,818 Junior Subordinated Debentures BHE junior subordinated debentures consists of the following as of December 31 (in millions): Par Value 2017 2016 Junior subordinated debentures, due 2044 $ — $ — $ 944 Junior subordinated debentures, due 2057 100 100 — Total BHE junior subordinated debentures - noncurrent $ 100 $ 100 $ 944 Long-term debt of subsidiaries consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (in millions): Par Value 2017 2016 PacifiCorp $ 7,061 $ 7,025 $ 7,079 MidAmerican Funding 5,319 5,259 4,592 NV Energy 4,577 4,581 4,582 Northern Powergrid 2,792 2,805 2,379 BHE Pipeline Group 800 796 990 BHE Transmission 4,348 4,334 4,058 BHE Renewables 3,636 3,594 3,674 HomeServices 247 247 — Total subsidiary debt $ 28,780 $ 28,641 $ 27,354 Reflected as: Current liabilities $ 2,431 $ 606 Noncurrent liabilities 26,210 26,748 Total subsidiary debt $ 28,641 $ 27,354 MidAmerican Energy's long-term debt consists of the following, including amounts maturing within one year and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 First mortgage bonds: 2.40%, due 2019 $ 500 $ 499 $ 499 3.70%, due 2023 250 248 248 3.50%, due 2024 500 501 501 3.10%, due 2027 375 372 — 4.80%, due 2043 350 346 345 4.40%, due 2044 400 394 394 4.25%, due 2046 450 445 445 3.95%, due 2047 475 470 — Notes: 5.95% Series, due 2017 — — 250 5.3% Series, due 2018 350 350 350 6.75% Series, due 2031 400 396 396 5.75% Series, due 2035 300 298 298 5.8% Series, due 2036 350 347 347 Transmission upgrade obligation, 4.45% and 3.42% due through 2035 and 2036, respectively 8 6 7 Variable-rate tax-exempt bond obligation series: (weighted average interest rate- 2017-1.91%, 2016-0.76%): Due 2023, issued in 1993 7 7 7 Due 2023, issued in 2008 57 57 57 Due 2024 35 35 35 Due 2025 13 13 13 Due 2036 33 33 33 Due 2038 45 45 45 Due 2046 30 29 29 Due 2047 150 149 — Capital lease obligations - 4.16%, due through 2020 2 2 2 Total $ 5,080 $ 5,042 $ 4,301

Subsidiary Debt (Tables)

Subsidiary Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	Senior Debt BHE senior debt represents unsecured senior obligations of BHE that are redeemable in whole or in part at any time generally with make-whole premiums. BHE senior debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (in millions): Par Value 2017 2016 1.10% Senior Notes, due 2017 $ — $ — $ 400 5.75% Senior Notes, due 2018 650 650 649 2.00% Senior Notes, due 2018 350 350 349 2.40% Senior Notes, due 2020 350 349 349 3.75% Senior Notes, due 2023 500 498 497 3.50% Senior Notes, due 2025 400 398 397 8.48% Senior Notes, due 2028 301 302 477 6.125% Senior Bonds, due 2036 1,670 1,660 1,690 5.95% Senior Bonds, due 2037 550 547 547 6.50% Senior Bonds, due 2037 225 222 987 5.15% Senior Notes, due 2043 750 739 739 4.50% Senior Notes, due 2045 750 737 737 Total BHE Senior Debt $ 6,496 $ 6,452 $ 7,818 Reflected as: Current liabilities $ 1,000 $ 400 Noncurrent liabilities 5,452 7,418 Total BHE Senior Debt $ 6,452 $ 7,818 Junior Subordinated Debentures BHE junior subordinated debentures consists of the following as of December 31 (in millions): Par Value 2017 2016 Junior subordinated debentures, due 2044 $ — $ — $ 944 Junior subordinated debentures, due 2057 100 100 — Total BHE junior subordinated debentures - noncurrent $ 100 $ 100 $ 944 Long-term debt of subsidiaries consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (in millions): Par Value 2017 2016 PacifiCorp $ 7,061 $ 7,025 $ 7,079 MidAmerican Funding 5,319 5,259 4,592 NV Energy 4,577 4,581 4,582 Northern Powergrid 2,792 2,805 2,379 BHE Pipeline Group 800 796 990 BHE Transmission 4,348 4,334 4,058 BHE Renewables 3,636 3,594 3,674 HomeServices 247 247 — Total subsidiary debt $ 28,780 $ 28,641 $ 27,354 Reflected as: Current liabilities $ 2,431 $ 606 Noncurrent liabilities 26,210 26,748 Total subsidiary debt $ 28,641 $ 27,354 MidAmerican Energy's long-term debt consists of the following, including amounts maturing within one year and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 First mortgage bonds: 2.40%, due 2019 $ 500 $ 499 $ 499 3.70%, due 2023 250 248 248 3.50%, due 2024 500 501 501 3.10%, due 2027 375 372 — 4.80%, due 2043 350 346 345 4.40%, due 2044 400 394 394 4.25%, due 2046 450 445 445 3.95%, due 2047 475 470 — Notes: 5.95% Series, due 2017 — — 250 5.3% Series, due 2018 350 350 350 6.75% Series, due 2031 400 396 396 5.75% Series, due 2035 300 298 298 5.8% Series, due 2036 350 347 347 Transmission upgrade obligation, 4.45% and 3.42% due through 2035 and 2036, respectively 8 6 7 Variable-rate tax-exempt bond obligation series: (weighted average interest rate- 2017-1.91%, 2016-0.76%): Due 2023, issued in 1993 7 7 7 Due 2023, issued in 2008 57 57 57 Due 2024 35 35 35 Due 2025 13 13 13 Due 2036 33 33 33 Due 2038 45 45 45 Due 2046 30 29 29 Due 2047 150 149 — Capital lease obligations - 4.16%, due through 2020 2 2 2 Total $ 5,080 $ 5,042 $ 4,301
Maturities of Long-term Debt [Table Text Block]	ly. Annual Repayments of Long-Term Debt The annual repayments of BHE and subsidiary debt for the years beginning January 1, 2018 and thereafter, excluding fair value adjustments and unamortized premiums, discounts and debt issuance costs, are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total BHE senior notes $ 1,000 $ — $ 350 $ — $ — $ 5,146 $ 6,496 BHE junior subordinated debentures — — — — — 100 100 PacifiCorp 588 351 39 425 606 5,052 7,061 MidAmerican Funding 350 501 2 — — 4,466 5,319 NV Energy 844 520 336 27 28 2,822 4,577 Northern Powergrid 66 78 483 26 501 1,638 2,792 BHE Pipeline Group 200 — — 200 — 400 800 BHE Transmission 160 160 269 — 378 3,381 4,348 BHE Renewables 209 473 168 175 172 2,439 3,636 HomeServices 14 20 27 33 153 — 247 Totals $ 3,431 $ 2,103 $ 1,674 $ 886 $ 1,838 $ 25,444 $ 35,376
MidAmerican Energy Company [Member]
Debt Instrument [Line Items]
Maturities of Long-term Debt [Table Text Block]	The annual repayments of MidAmerican Energy's long-term debt for the years beginning January 1, 2018 , and thereafter, excluding unamortized premiums, discounts and debt issuance costs, are as follows (in millions): 2018 $ 350 2019 501 2020 2 2021 — 2022 — 2023 and thereafter 4,227
Sierra Pacific Power Company [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	Sierra Pacific 's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 General and refunding mortgage securities: 3.375% Series T, due 2023 $ 250 $ 248 $ 248 2.600% Series U, due 2026 400 396 395 6.750% Series P, due 2037 252 255 255 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.250% Pollution Control Series 2016A, due 2029 (1) 20 20 20 1.500% Gas Facilities Series 2016A, due 2031 (1) 59 58 58 3.000% Gas and Water Series 2016B, due 2036 (2) 60 63 64 Variable-rate series (2017 - 1.690% to 1.840%, 2016 - 0.788% to 0.800%): Water Facilities Series 2016C, due 2036 30 30 29 Water Facilities Series 2016D, due 2036 25 25 25 Water Facilities Series 2016E, due 2036 25 25 25 Capital and financial lease obligations (2017 - 2.700% to 10.396%, 2016 - 2.700% to 10.130%), due through 2054 34 34 34 Total long-term debt and financial and capital leases $ 1,155 $ 1,154 $ 1,153 Reflected as: Current portion of long-term debt and financial and capital lease obligations $ 2 $ 1 Long-term debt and financial and capital lease obligations 1,152 1,152 Total long-term debt and financial and capital leases $ 1,154 $ 1,153 (1) Subject to mandatory purchase by Sierra Pacific in June 2019 at which date the interest rate may be adjusted from time to time. (2) Subject to mandatory purchase by Sierra Pacific in June 2022 at which date the interest rate may be adjusted from time to time.
Maturities of Long-term Debt [Table Text Block]	The annual repayments of long-term debt and capital and financial leases for the years beginning January 1, 2018 and thereafter, are as follows (in millions): Long-term Capital and Financial Debt Lease Obligations Total 2018 $ — $ 4 $ 4 2019 — 4 4 2020 — 4 4 2021 — 4 4 2022 — 3 3 Thereafter 1,121 47 1,168 Total 1,121 66 1,187 Unamortized premium, discount and debt issuance cost (1 ) — (1 ) Amounts representing interest — (32 ) (32 ) Total $ 1,120 $ 34 $ 1,154
Nevada Power Company [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	Nevada Power 's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 General and refunding mortgage securities: 6.500% Series O, due 2018 $ 324 $ 324 $ 324 6.500% Series S, due 2018 499 499 498 7.125% Series V, due 2019 500 499 499 6.650% Series N, due 2036 367 357 357 6.750% Series R, due 2037 349 346 345 5.375% Series X, due 2040 250 247 247 5.450% Series Y, due 2041 250 236 236 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.800% Pollution Control Bonds Series 2017A, due 2032 (1) 40 40 — 1.600% Pollution Control Bonds Series 2017, due 2036 (1) 40 39 — 1.600% Pollution Control Bonds Series 2017B, due 2039 (1) 13 13 — Variable-rate series - 1.890% to 1.928% Pollution Control Bonds Series 2006A, due 2032 — — 38 Pollution Control Bonds Series 2006, due 2036 — — 37 Capital and financial lease obligations - 2.750% to 11.600%, due through 2054 475 475 485 Total long-term debt and financial and capital leases $ 3,107 $ 3,075 $ 3,066 Reflected as: Current portion of long-term debt and financial and capital lease obligations $ 842 $ 17 Long-term debt and financial and capital lease obligations 2,233 3,049 Total long-term debt and financial and capital leases $ 3,075 $ 3,066 (1) Subject to mandatory purchase by Nevada Power in May 2020 at which date the interest rate may be adjusted from time to time.
Maturities of Long-term Debt [Table Text Block]	The annual repayments of long-term debt and capital and financial leases for the years beginning January 1, 2018 and thereafter, are as follows (in millions): Long-term Capital and Financial Debt Lease Obligations Total 2018 $ 823 $ 75 $ 898 2019 500 76 576 2020 — 76 76 2021 — 80 80 2022 — 75 75 Thereafter 1,309 760 2,069 Total 2,632 1,142 3,774 Unamortized premium, discount and debt issuance cost (32 ) — (32 ) Executory costs — (92 ) (92 ) Amounts representing interest — (575 ) (575 ) Total $ 2,600 $ 475 $ 3,075
PacifiCorp [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	PacifiCorp's long-term debt and capital lease obligations were as follows as of December 31 (dollars in millions): 2017 2016 Average Average Principal Carrying Interest Carrying Interest Amount Value Rate Value Rate First mortgage bonds: 2.95% to 8.53%, due 2018 to 2022 $ 1,875 $ 1,872 4.80 % $ 1,872 4.80 % 2.95% to 8.23%, due 2023 to 2026 1,224 1,218 4.10 1,217 4.10 7.70% due 2031 300 298 7.70 298 7.70 5.25% to 6.25%, due 2034 to 2037 2,050 2,040 5.90 2,039 5.90 4.10% to 6.35%, due 2038 to 2042 1,250 1,236 5.60 1,235 5.60 Variable-rate series, tax-exempt bond obligations (2017-1.60% to 1.87%; 2016-0.69% to 0.86%): Due 2018 to 2020 79 79 1.77 91 0.85 Due 2018 to 2025 (1) 70 70 1.81 108 0.74 Due 2024 (1)(2) 143 142 1.73 142 0.70 Due 2024 to 2025 (2) 50 50 1.72 50 0.80 Total long-term debt 7,041 7,005 7,052 Capital lease obligations: 8.75% to 14.61%, due through 2035 20 20 11.46 27 11.09 Total long-term debt and capital lease obligations $ 7,061 $ 7,025 $ 7,079 Reflected as: 2017 2016 Current portion of long-term debt and capital lease obligations $ 588 $ 58 Long-term debt and capital lease obligations 6,437 7,021 Total long-term debt and capital lease obligations $ 7,025 $ 7,079 1) Supported by $216 million and $255 million of fully available letters of credit issued under committed bank arrangements as of December 31, 2017 and 2016 , respectively. 2) Secured by pledged first mortgage bonds registered to and held by the tax-exempt bond trustee generally with the same interest rates, maturity dates and redemption provisions as the tax-exempt bond obligations.
Maturities of Long-term Debt [Table Text Block]	As of December 31, 2017 , the annual principal maturities of long-term debt and total capital lease obligations for 2018 and thereafter are as follows (in millions): Long-term Capital Lease Debt Obligations Total 2018 $ 586 $ 4 $ 590 2019 350 4 354 2020 38 3 41 2021 420 6 426 2022 605 2 607 Thereafter 5,042 18 5,060 Total 7,041 37 7,078 Unamortized discount and debt issuance costs (36 ) — (36 ) Amounts representing interest — (17 ) (17 ) Total $ 7,005 $ 20 $ 7,025
PacifiCorp [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	PacifiCorp PacifiCorp's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs as of December 31 (dollars in millions): Par Value 2017 2016 First mortgage bonds: 2.95% to 8.53%, due through 2022 $ 1,875 $ 1,872 $ 1,872 2.95% to 8.23%, due 2023 to 2026 1,224 1,218 1,217 7.70% due 2031 300 298 298 5.25% to 6.25%, due 2034 to 2037 2,050 2,040 2,039 4.10% to 6.35%, due 2038 to 2042 1,250 1,236 1,235 Variable-rate series, tax-exempt bond obligations (2017-1.60% to 1.87%; 2016-0.69% to 0.86%): Due 2018 to 2020 79 79 91 Due 2018 to 2025 (1) 70 70 108 Due 2024 (1)(2) 143 142 142 Due 2024 to 2025 (2) 50 50 50 Capital lease obligations - 8.75% to 14.61%, due through 2035 20 20 27 Total PacifiCorp $ 7,061 $ 7,025 $ 7,079 (1) Supported by $216 million and $255 million of fully available letters of credit issued under committed bank arrangements as of December 31, 2017 and 2016 , respectively. (2) Secured by pledged first mortgage bonds registered to and held by the tax-exempt bond trustee generally with the same interest rates, maturity dates and redemption provisions as the tax-exempt bond obligations.
MidAmerican Funding [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	MidAmerican Funding MidAmerican Funding's long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 MidAmerican Funding: 6.927% Senior Bonds, due 2029 $ 239 $ 216 $ 291 MidAmerican Energy: Tax-exempt bond obligations - Variable-rate tax-exempt bond obligation series: (2017-1.91%, 2016-0.76%), due 2023-2047 370 368 219 First Mortgage Bonds: 2.40%, due 2019 500 499 499 3.70%, due 2023 250 248 248 3.50%, due 2024 500 501 501 3.10%, due 2027 375 372 — 4.80%, due 2043 350 346 345 4.40%, due 2044 400 394 394 4.25%, due 2046 450 445 445 3.95%, due 2047 475 470 — Notes: 5.95% Series, due 2017 — — 250 5.30% Series, due 2018 350 350 350 6.75% Series, due 2031 400 396 396 5.75% Series, due 2035 300 298 298 5.80% Series, due 2036 350 348 347 Transmission upgrade obligation, 4.45% and 3.42% due through 2035 and 2036, respectively 8 6 7 Capital lease obligations - 4.16%, due through 2020 2 2 2 Total MidAmerican Energy 5,080 5,043 4,301 Total MidAmerican Funding $ 5,319 $ 5,259 $ 4,592
NV Energy, Inc. [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	NV Energy NV Energy's long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 NV Energy - 6.250% Senior Notes, due 2020 $ 315 $ 337 $ 363 Nevada Power: General and refunding mortgage securities: 6.500% Series O, due 2018 324 324 324 6.500% Series S, due 2018 499 499 498 7.125% Series V, due 2019 500 499 499 6.650% Series N, due 2036 367 359 357 6.750% Series R, due 2037 349 348 345 5.375% Series X, due 2040 250 248 247 5.450% Series Y, due 2041 250 244 236 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.800% Pollution Control Bonds Series 2017A, due 2032 (1) 40 40 — 1.600% Pollution Control Bonds Series 2017, due 2036 (1) 40 39 — 1.600% Pollution Control Bonds Series 2017B, due 2039 (1) 13 13 — Variable-rate series - 1.890% to 1.928% Pollution Control Bonds Series 2006A, due 2032 — — 38 Pollution Control Bonds Series 2006, due 2036 — — 37 Capital and financial lease obligations - 2.750% to 11.600%, due through 2054 475 475 485 Total Nevada Power 3,107 3,088 3,066 Sierra Pacific: General and refunding mortgage securities: 3.375% Series T, due 2023 250 249 248 2.600% Series U, due 2026 400 396 395 6.750% Series P, due 2037 252 256 255 Tax-exempt refunding revenue bond obligations: Fixed-rate series: 1.250% Pollution Control Series 2016A, due 2029 (2) 20 20 20 1.500% Gas Facilities Series 2016A, due 2031 (2) 59 58 58 3.000% Gas and Water Series 2016B, due 2036 (3) 60 63 64 Variable-rate series (2017 - 1.690% to 1.840%, 2016 - 0.788% to 0.800%): Water Facilities Series 2016C, due 2036 30 30 29 Water Facilities Series 2016D, due 2036 25 25 25 Water Facilities Series 2016E, due 2036 25 25 25 Capital and financial lease obligations (2017 - 2.700% to 10.396%, 2016 - 2.700% to 10.130%), due through 2054 34 34 34 Total Sierra Pacific 1,155 1,156 1,153 Total NV Energy $ 4,577 $ 4,581 $ 4,582
Northern Powergrid Holdings [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	gages. Northern Powergrid Northern Powergrid and its subsidiaries' long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value (1) 2017 2016 8.875% Bonds, due 2020 $ 135 $ 144 $ 136 9.25% Bonds, due 2020 270 279 259 3.901% to 4.586% European Investment Bank loans, due 2018 to 2022 366 366 333 7.25% Bonds, due 2022 270 279 257 2.50% Bonds due 2025 203 200 182 2.073% European Investment Bank loan, due 2025 68 69 62 2.564% European Investment Bank loans, due 2027 338 336 308 7.25% Bonds, due 2028 250 256 234 4.375% Bonds, due 2032 203 199 182 5.125% Bonds, due 2035 270 267 243 5.125% Bonds, due 2035 203 200 183 Variable-rate bond, due 2026 (2) 216 210 — Total Northern Powergrid $ 2,792 $ 2,805 $ 2,379 (1) The par values for these debt instruments are denominated in sterling. (2) Amortizes semiannually and the Company has entered into an interest rate swap that fixes the interest rate on 85% of the outstanding debt. The variable interest rate as of December 31, 2017 was 2.27% while the fixed interest rate was 2.82% .
BHE Pipeline Group [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	BHE Pipeline Group BHE Pipeline Group 's long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 Northern Natural Gas: 5.75% Senior Notes, due 2018 $ 200 $ 200 $ 199 4.25% Senior Notes, due 2021 200 199 199 5.8% Senior Bonds, due 2037 150 149 149 4.1% Senior Bonds, due 2042 250 248 248 Total Northern Natural Gas 800 796 795 Kern River: 4.893% Senior Notes, due 2018 — — 195 Total BHE Pipeline Group $ 800 $ 796 $ 990
BHE Transmission [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	BHE Transmission BHE Transmission 's long-term debt consists of the following, including fair value adjustments and unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value (1) 2017 2016 AltaLink Investments, L.P.: Series 12-1 Senior Bonds, 3.674%, due 2019 $ 159 $ 162 $ 153 Series 13-1 Senior Bonds, 3.265%, due 2020 159 161 152 Series 15-1 Senior Bonds, 2.244%, due 2022 159 158 148 Total AltaLink Investments, L.P. 477 481 453 AltaLink, L.P.: Series 2008-1 Notes, 5.243%, due 2018 159 159 148 Series 2013-2 Notes, 3.621%, due 2020 100 99 93 Series 2012-2 Notes, 2.978%, due 2022 219 218 204 Series 2013-4 Notes, 3.668%, due 2023 398 397 371 Series 2014-1 Notes, 3.399%, due 2024 278 278 260 Series 2016-1 Notes, 2.747%, due 2026 278 277 259 Series 2006-1 Notes, 5.249%, due 2036 119 119 111 Series 2010-1 Notes, 5.381%, due 2040 100 99 93 Series 2010-2 Notes, 4.872%, due 2040 119 119 111 Series 2011-1 Notes, 4.462%, due 2041 219 218 204 Series 2012-1 Notes, 3.990%, due 2042 418 412 385 Series 2013-3 Notes, 4.922%, due 2043 278 278 260 Series 2014-3 Notes, 4.054%, due 2044 235 233 218 Series 2015-1 Notes, 4.090%, due 2045 278 277 259 Series 2016-2 Notes, 3.717%, due 2046 358 356 333 Series 2013-1 Notes, 4.446%, due 2053 199 198 186 Series 2014-2 Notes, 4.274%, due 2064 103 103 97 Total AltaLink, L.P. 3,858 3,840 3,592 Other: Construction Loan, 5.660%, due 2020 13 13 13 Total BHE Transmission $ 4,348 $ 4,334 $ 4,058 (1) The par values for these debt instruments are denominated in Canadian dollars.
BHE Renewables [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	llars. BHE Renewables BHE Renewables ' long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 Fixed-rate (1) : CE Generation Bonds, 7.416%, due 2018 $ — $ — $ 67 Salton Sea Funding Corporation Bonds, 7.475%, due 2018 — — 31 Cordova Funding Corporation Bonds, 8.48% to 9.07%, due 2019 — — 97 Bishop Hill Holdings Senior Notes, 5.125%, due 2032 94 93 99 Solar Star Funding Senior Notes, 3.950%, due 2035 314 310 311 Solar Star Funding Senior Notes, 5.375%, due 2035 975 965 966 Grande Prairie Wind Senior Notes, 3.860%, due 2037 408 404 414 Topaz Solar Farms Senior Notes, 5.750%, due 2039 755 745 780 Topaz Solar Farms Senior Notes, 4.875%, due 2039 219 217 229 Alamo 6 Senior Notes, 4.170%, due 2042 232 229 — Other 19 19 22 Variable-rate (1) : Pinyon Pines I and II Term Loans, due 2019 (2) 334 333 355 Wailuku Special Purpose Revenue Bonds, 0.90%, due 2021 — — 7 TX Jumbo Road Term Loan, due 2025 (2) 198 193 206 Marshall Wind Term Loan, due 2026 (2) 88 86 90 Total BHE Renewables $ 3,636 $ 3,594 $ 3,674 (1) Amortizes quarterly or semiannually. (2) The term loans have variable interest rates based on LIBOR plus a margin that varies during the terms of the agreements. The Company has entered into interest rate swaps that fix the interest rate on 75% of the Pinyon Pines outstanding debt and 100% of the TX Jumbo Road and Marshall Wind outstanding debt. The variable interest rate as of December 31, 2017 and 2016 was 3.32% and 2.62% , respectively, while the fixed interest rates as of December 31, 2017 and 2016 ranged from 3.21% to 3.63% .
HomeServices [Member]
Debt Instrument [Line Items]
Subsidiary Debt [Table Text Block]	HomeServices HomeServices ' long-term debt consists of the following, including unamortized premiums, discounts and debt issuance costs, as of December 31 (dollars in millions): Par Value 2017 2016 Variable-rate (1) : Variable-rate term loan, 2017 - 2.819%, due 2022 $ 247 $ 247 $ — (1) Amortizes quarterly.

Risk Management and Hedging A50

Risk Management and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table, which reflects master netting arrangements and excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of the Company's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Consolidated Balance Sheets (in millions): Other Other Other Current Other Current Long-term Assets Assets Liabilities Liabilities Total As of December 31, 2017: Not designated as hedging contracts: Commodity assets (1) $ 29 $ 92 $ 6 $ 4 $ 131 Commodity liabilities (1) (6 ) — (64 ) (93 ) (163 ) Interest rate assets 16 — — — 16 Interest rate liabilities — — (1 ) (7 ) (8 ) Total 39 92 (59 ) (96 ) (24 ) Designated as hedging contracts: Commodity assets 4 9 2 1 16 Commodity liabilities (3 ) (7 ) (3 ) (4 ) (17 ) Interest rate assets — 8 — — 8 Interest rate liabilities — — — — — Total 1 10 (1 ) (3 ) 7 Total derivatives 40 102 (60 ) (99 ) (17 ) Cash collateral receivable — — 18 58 76 Total derivatives - net basis $ 40 $ 102 $ (42 ) $ (41 ) $ 59 As of December 31, 2016: Not designated as hedging contracts: Commodity assets (1) $ 42 $ 86 $ 5 $ 2 $ 135 Commodity liabilities (1) (10 ) — (46 ) (150 ) (206 ) Interest rate assets 15 — — — 15 Interest rate liabilities — — (4 ) (6 ) (10 ) Total 47 86 (45 ) (154 ) (66 ) Designated as hedging contracts: Commodity assets 1 — 2 3 6 Commodity liabilities — — (14 ) (8 ) (22 ) Interest rate assets — 8 — — 8 Interest rate liabilities — — (3 ) — (3 ) Total 1 8 (15 ) (5 ) (11 ) Total derivatives 48 94 (60 ) (159 ) (77 ) Cash collateral receivable — — 13 61 74 Total derivatives - net basis $ 48 $ 94 $ (47 ) $ (98 ) $ (3 ) (1) The Company's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of December 31, 2017 and 2016 , a net regulatory asset of $119 million and $148 million , respectively, was recorded related to the net derivative liability of $32 million and $71 million , respectively. The difference between the net regulatory asset and the net derivative liability relates primarily to a power purchase agreement derivative at BHE Renewables.
Schedule of Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Contracts [Table Text Block]	The following table reconciles the beginning and ending balances of the Company's net regulatory assets and summarizes the pre-tax gains and losses on commodity derivative contracts recognized in net regulatory assets, as well as amounts reclassified to earnings for the years ended December 31 (in millions): Commodity Derivatives 2017 2016 2015 Beginning balance $ 148 $ 250 $ 223 Changes in fair value recognized in net regulatory assets 53 (30 ) 128 Net gains (losses) reclassified to operating revenue 10 (5 ) 1 Net losses reclassified to cost of sales (92 ) (67 ) (102 ) Ending balance $ 119 $ 148 $ 250
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Certain commodity derivative contracts have settled and the fair value at the date of settlement remains in AOCI and is recognized in earnings when the forecasted transactions impact earnings. The following table reconciles the beginning and ending balances of the Company's AOCI (pre-tax) and summarizes pre-tax gains and losses on commodity derivative contracts designated and qualifying as cash flow hedges recognized in OCI, as well as amounts reclassified to earnings for the years ended December 31 (in millions): Commodity Derivatives 2017 2016 2015 Beginning balance $ 16 $ 46 $ 32 Changes in fair value recognized in OCI 15 26 52 Net gains reclassified to operating revenue 1 1 9 Net losses reclassified to cost of sales (32 ) (57 ) (47 ) Ending balance $ — $ 16 $ 46
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The following table summarizes the net notional amounts of outstanding derivative contracts with fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Electricity purchases Megawatt hours 4 5 Natural gas purchases Decatherms 310 271 Fuel purchases Gallons — 11 Interest rate swaps US$ 679 714 Interest rate swaps £ 136 — Mortgage commitments, net US$ (422 ) (309 )
PacifiCorp [Member]
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table, which reflects master netting arrangements and excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of PacifiCorp's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Consolidated Balance Sheets (in millions): Other Other Other Current Other Current Long-term Assets Assets Liabilities Liabilities Total As of December 31, 2017: Not designated as hedging contracts (1) : Commodity assets $ 11 $ 1 $ 1 $ — $ 13 Commodity liabilities (3 ) — (32 ) (82 ) (117 ) Total 8 1 (31 ) (82 ) (104 ) Total derivatives 8 1 (31 ) (82 ) (104 ) Cash collateral receivable — — 17 57 74 Total derivatives - net basis $ 8 $ 1 $ (14 ) $ (25 ) $ (30 ) As of December 31, 2016: Not designated as hedging contracts (1) : Commodity assets $ 24 $ 2 $ 1 $ — $ 27 Commodity liabilities (6 ) — (14 ) (84 ) (104 ) Total 18 2 (13 ) (84 ) (77 ) Total derivatives 18 2 (13 ) (84 ) (77 ) Cash collateral receivable — — 10 59 69 Total derivatives - net basis $ 18 $ 2 $ (3 ) $ (25 ) $ (8 ) (1) PacifiCorp's commodity derivatives are generally included in rates and as of December 31, 2017 and 2016 , a regulatory asset of $101 million and $73 million , respectively, was recorded related to the net derivative liability of $104 million and $77 million , respectively.
Schedule of Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Contracts [Table Text Block]	The following table reconciles the beginning and ending balances of PacifiCorp's regulatory assets and summarizes the pre-tax gains and losses on commodity derivative contracts recognized in regulatory assets, as well as amounts reclassified to earnings for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ 73 $ 133 $ 85 Changes in fair value recognized in regulatory assets 47 (27 ) 82 Net gains reclassified to operating revenue 9 10 40 Net losses reclassified to energy costs (28 ) (43 ) (74 ) Ending balance $ 101 $ 73 $ 133
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The following table summarizes the net notional amounts of outstanding commodity derivative contracts with fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Electricity (sales) Megawatt hours (9 ) (3 ) Natural gas purchases Decatherms 113 84 Fuel oil purchases Gallons — 11
MidAmerican Energy Company [Member]
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table, which reflects master netting arrangements and excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of MidAmerican Energy's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Balance Sheets (in millions): Other Other Other Current Other Current Long-term Assets Assets Liabilities Liabilities Total As of December 31, 2017: Not designated as hedging contracts (1) : Commodity assets $ 6 $ — $ 1 $ — $ 7 Commodity liabilities (1 ) — (7 ) (2 ) (10 ) Total derivatives 5 — (6 ) (2 ) (3 ) Cash collateral receivable — — — — — Total derivatives - net basis $ 5 $ — $ (6 ) $ (2 ) $ (3 ) As of December 31, 2016: Not designated as hedging contracts (1) : Commodity assets $ 8 $ 2 $ — $ — $ 10 Commodity liabilities (2 ) — (3 ) (1 ) (6 ) Total derivatives 6 2 (3 ) (1 ) 4 Cash collateral receivable — — 1 — 1 Total derivatives - net basis $ 6 $ 2 $ (2 ) $ (1 ) $ 5 (1) MidAmerican Energy's commodity derivatives not designated as hedging contracts are generally included in regulated rates. Accordingly, as of December 31, 2017 , a net regulatory asset of $3 million was recorded related to the net derivative a liability of $3 million , and as of December 31, 2016 , a net regulatory liability of $(4) million was recorded related to the net derivative asset of $4 million .
Schedule of Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Contracts [Table Text Block]	The following table reconciles the beginning and ending balances of MidAmerican Energy's net regulatory assets (liabilities) and summarizes the pre-tax gains and losses on commodity derivative contracts recognized in net regulatory assets (liabilities), as well as amounts reclassified to earnings for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ (4 ) $ 20 $ 38 Changes in fair value recognized in net regulatory assets (liabilities) 16 3 40 Net gains (losses) reclassified to operating revenue 1 (15 ) (42 ) Net losses reclassified to cost of fuel, energy and capacity (4 ) — (1 ) Net losses reclassified to cost of gas sold (6 ) (12 ) (15 ) Ending balance $ 3 $ (4 ) $ 20
Schedule Of Nonregulated Derivatives Not Designated As Hedging Instruments Gain (Loss) In Statement Of Financial Performance [Table Text Block]	The following table summarizes the pre-tax unrealized gains (losses) included on the Statements of Operations associated with MidAmerican Energy's derivative contracts not designated as hedging contracts and not recorded as a net regulatory asset or liability for the years ended December 31 (in millions): 2017 2016 2015 Nonregulated operating revenue $ — $ — $ 15 Regulated cost of fuel, energy and capacity — — 2 Nonregulated cost of sales — — (21 ) Total $ — $ — $ (4 )
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table reconciles the beginning and ending balances of MidAmerican Energy's accumulated other comprehensive loss (pre-tax) and summarizes pre-tax gains and losses on derivative contracts designated and qualifying as cash flow hedges recognized in OCI, as well as amounts reclassified to earnings, for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ — $ 45 $ 34 Transfer to affiliate — (45 ) — Changes in fair value recognized in OCI — — 58 Net losses reclassified to nonregulated cost of sales — — (47 ) Ending balance $ — $ — $ 45
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The following table summarizes the net notional amounts of outstanding derivative contracts with fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Natural gas purchases Decatherms 21 18
Nevada Power Company [Member]
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table, which excludes contracts that have been designated as normal under the normal purchases or normal sales exception afforded by GAAP, summarizes the fair value of Nevada Power 's derivative contracts, on a gross basis, and reconciles those amounts to the amounts presented on a net basis on the Consolidated Balance Sheets (in millions): Other Other Current Long-term Liabilities Liabilities Total As of December 31, 2017: Commodity derivative liabilities (1) $ (2 ) $ (1 ) $ (3 ) As of December 31, 2016: Commodity derivative liabilities (1) $ (7 ) $ (7 ) $ (14 ) (1) Nevada Power 's commodity derivatives not designated as hedging contracts are included in regulated rates and as of December 31 , 2017 and 2016 , a regulatory asset of $3 million and $14 million , respectively, was recorded related to the derivative liability of $3 million and $14 million , respectively.
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The following table summarizes the net notional amounts of outstanding derivative contracts with indexed and fixed price terms that comprise the mark-to-market values as of December 31 (in millions): Unit of Measure 2017 2016 Electricity sales Megawatt hours — (2 ) Natural gas purchases Decatherms 125 114

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets and Liabilities Net Measured On Recurring Basis Unobservable Input Reconciliation [Table Text Block]	The following table reconciles the beginning and ending balances of the Company's assets and liabilities measured at fair value on a recurring basis using significant Level 3 inputs for the years ended December 31 (in millions): Commodity Derivatives Interest Rate Derivatives Auction Rate Securities 2017 2016 2015 2017 2016 2015 2017 2016 2015 Beginning balance $ 60 $ 47 $ 51 $ 6 $ 4 $ — $ — $ 44 $ 45 Changes included in earnings 23 8 19 147 121 87 — 5 — Changes in fair value recognized in OCI (3 ) (2 ) (7 ) — — — — 8 (1 ) Changes in fair value recognized in net regulatory assets (1 ) (11 ) (19 ) — — — — — — Purchases 1 1 1 4 — — — — — Redemptions — — — — — — — (57 ) — Settlements 14 17 2 (148 ) (119 ) (86 ) — — — Transfers from Level 2 — — — — — 3 — — — Ending balance $ 94 $ 60 $ 47 $ 9 $ 6 $ 4 $ — $ — $ 44
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents the fair value of plan assets, by major category, for the Company's defined benefit pension plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 10 $ 76 $ — $ 86 Debt securities: United States government obligations 218 — — 218 Corporate obligations — 350 — 350 Municipal obligations — 16 — 16 Agency, asset and mortgage-backed obligations — 110 — 110 Equity securities: United States companies 622 — — 622 International companies 136 — — 136 Investment funds (2) 83 20 — 103 Total assets in the fair value hierarchy $ 1,069 $ 572 $ — 1,641 Investment funds (2) measured at net asset value 1,019 Limited partnership interests (3) measured at net asset value 63 Real estate funds measured at net asset value 38 Total assets measured at fair value $ 2,761 As of December 31, 2016: Cash equivalents $ 4 $ 54 $ — $ 58 Debt securities: United States government obligations 161 — — 161 International government obligations — 2 — 2 Corporate obligations — 295 — 295 Municipal obligations — 20 — 20 Agency, asset and mortgage-backed obligations — 112 — 112 Equity securities: United States companies 583 — — 583 International companies 117 — — 117 Investment funds (2) 146 — — 146 Total assets in the fair value hierarchy $ 1,011 $ 483 $ — 1,494 Investment funds (2) measured at net asset value 920 Limited partnership interests (3) measured at net asset value 61 Real estate funds measured at net asset value 50 Total assets measured at fair value $ 2,525 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 62% and 38% , respectively, for both 2017 and 2016 . Additionally, these funds are invested in United States and international securities of approximately 68% and 32% , respectively, for 2017 and 60% and 40% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of plan assets, by major category, for the Company's defined benefit other postretirement plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 11 $ 3 $ — $ 14 Debt securities: United States government obligations 20 — — 20 Corporate obligations — 36 — 36 Municipal obligations — 46 — 46 Agency, asset and mortgage-backed obligations — 29 — 29 Equity securities: United States companies 185 — — 185 International companies 8 — — 8 Investment funds 219 1 — 220 Total assets in the fair value hierarchy $ 443 $ 115 $ — 558 Investment funds measured at net asset value 174 Limited partnership interests measured at net asset value 4 Total assets measured at fair value $ 736 As of December 31, 2016: Cash equivalents $ 18 $ 2 $ — $ 20 Debt securities: United States government obligations 19 — — 19 Corporate obligations — 29 — 29 Municipal obligations — 39 — 39 Agency, asset and mortgage-backed obligations — 25 — 25 Equity securities: United States companies 217 — — 217 International companies 5 — — 5 Investment funds (2) 152 — — 152 Total assets in the fair value hierarchy $ 411 $ 95 $ — 506 Investment funds (2) measured at net asset value 156 Limited partnership interests (3) measured at net asset value 4 Total assets measured at fair value $ 666 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 68% and 32% , respectively, for 2017 and 63% and 37% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 73% and 27% , respectively, for 2017 and 72% and 28% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of the UK Plan assets, by major category (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 4 $ 30 $ — $ 34 Debt securities: United Kingdom government obligations 870 — — 870 Equity securities: Investment funds (2) — 1,027 — 1,027 Real estate funds — — 230 230 Total $ 874 $ 1,057 $ 230 2,161 Investment funds (2) measured at net asset value 207 Total assets measured at fair value $ 2,368 As of December 31, 2016: Cash equivalents $ 4 $ 83 $ — $ 87 Debt securities: United Kingdom government obligations 718 — — 718 Equity securities: Investment funds (2) — 1,095 — 1,095 Real estate funds — — 105 105 Total $ 722 $ 1,178 $ 105 2,005 Investment funds (2) measured at net asset value 164 Total assets measured at fair value $ 2,169 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 21% and 79% , respectively, for 2017 and 44% and 56% , respectively, for 2016 . The following table presents the Company's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ 1 $ 42 $ 104 $ (29 ) $ 118 Interest rate derivatives — 15 9 — 24 Mortgage loans held for sale — 465 — — 465 Money market mutual funds (2) 685 — — — 685 Debt securities: United States government obligations 176 — — — 176 International government obligations — 5 — — 5 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Equity securities: United States companies 288 — — — 288 International companies 1,968 — — — 1,968 Investment funds 178 — — — 178 $ 3,296 $ 565 $ 113 $ (29 ) $ 3,945 Liabilities: Commodity derivatives $ (3 ) $ (167 ) $ (10 ) $ 105 $ (75 ) Interest rate derivatives — (8 ) — — (8 ) $ (3 ) $ (175 ) $ (10 ) $ 105 $ (83 ) As of December 31, 2016: Assets: Commodity derivatives $ 5 $ 49 $ 87 $ (22 ) $ 119 Interest rate derivatives — 16 7 — 23 Mortgage loans held for sale — 359 — — 359 Money market mutual funds (2) 586 — — — 586 Debt securities: United States government obligations 161 — — — 161 International government obligations — 3 — — 3 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Agency, asset and mortgage-backed obligations — 2 — — 2 Equity securities: United States companies 250 — — — 250 International companies 1,190 — — — 1,190 Investment funds 147 — — — 147 $ 2,339 $ 467 $ 94 $ (22 ) $ 2,878 Liabilities: Commodity derivatives $ (2 ) $ (199 ) $ (27 ) $ 96 $ (132 ) Interest rate derivatives (1 ) (11 ) (1 ) — (13 ) $ (3 ) $ (210 ) $ (28 ) $ 96 $ (145 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $76 million and $74 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying value and estimated fair value of the Company's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 35,193 $ 40,522 $ 36,116 $ 40,718
Nevada Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents Nevada Power 's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Total As of December 31, 2017: Assets - investment funds $ 2 $ — $ — $ 2 Liabilities - commodity derivatives $ — $ — $ (3 ) $ (3 ) As of December 31, 2016: Assets: Money market mutual funds (1) $ 220 $ — $ — $ 220 Investment funds 6 — — 6 $ 226 $ — $ — $ 226 Liabilities - commodity derivatives $ — $ — $ (14 ) $ (14 ) (1) Amounts are included in cash and cash equivalents on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table reconciles the beginning and ending balances of Nevada Power 's commodity derivative liabilities measured at fair value on a recurring basis using significant Level 3 inputs for the years ended December 31 (in millions): 2017 2016 2015 Beginning balance $ (14 ) $ (22 ) $ (30 ) Changes in fair value recognized in regulatory assets (3 ) (4 ) — Settlements 14 12 8 Ending balance $ (3 ) $ (14 ) $ (22 )
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying value and estimated fair value of Nevada Power 's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 2,600 $ 3,088 $ 2,581 $ 3,040
PacifiCorp [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit pension plan (in millions): Input Levels for Fair Value Measurements Level 1 (1) Level 2 (1) Level 3 (1) Total As of December 31, 2017: Cash equivalents $ — $ 43 $ — $ 43 Debt securities: United States government obligations 45 — — 45 Corporate obligations — 60 — 60 Municipal obligations — 9 — 9 Agency, asset and mortgage-backed obligations — 37 — 37 Equity securities: United States companies 416 — — 416 International companies 22 — — 22 Total assets in the fair value hierarchy $ 483 $ 149 $ — 632 Investment funds (2) measured at net asset value 416 Limited partnership interests (3) measured at net asset value 63 Investments at fair value $ 1,111 As of December 31, 2016: Cash equivalents $ — $ 10 $ — $ 10 Debt securities: United States government obligations 25 — — 25 Corporate obligations — 36 — 36 Municipal obligations — 6 — 6 Agency, asset and mortgage-backed obligations — 37 — 37 Equity securities: United States companies 389 — — 389 International companies 15 — — 15 Investment funds (2) 83 — — 83 Total assets in the fair value hierarchy $ 512 $ 89 $ — 601 Investment funds (2) measured at net asset value 337 Limited partnership interests (3) measured at net asset value 61 Investments at fair value $ 999 (1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 60% and 40% respectively, for 2017 and 54% and 46% , respectively, for 2016 , and are invested in United States and international securities of approximately 57% and 43% , respectively, for 2017 and 39% and 61% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit other postretirement plan (in millions): Input Levels for Fair Value Measurements Level 1 (1) Level 2 (1) Level 3 (1) Total As of December 31, 2017: Cash and cash equivalents $ 4 $ 3 $ — $ 7 Debt securities: United States government obligations 11 — — 11 Corporate obligations — 16 — 16 Municipal obligations — 2 — 2 Agency, asset and mortgage-backed obligations — 16 — 16 Equity securities: United States companies 98 — — 98 International companies 6 — — 6 Investment funds (2) 32 — — 32 Total assets in the fair value hierarchy $ 151 $ 37 $ — 188 Investment funds (2) measured at net asset value 140 Limited partnership interests (3) measured at net asset value 4 Investments at fair value $ 332 As of December 31, 2016: Cash and cash equivalents $ 4 $ 1 $ — $ 5 Debt securities: United States government obligations 11 — — 11 Corporate obligations — 13 — 13 Municipal obligations — 2 — 2 Agency, asset and mortgage-backed obligations — 13 — 13 Equity securities: United States companies 93 — — 93 International companies 4 — — 4 Investment funds (2) 32 — — 32 Total assets in the fair value hierarchy $ 144 $ 29 $ — 173 Investment funds (2) measured at net asset value 125 Limited partnership interests (3) measured at net asset value 4 Investments at fair value $ 302 (1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 63% and 37% , respectively, for 2017 and 62% and 38% , respectively, for 2016 , and are invested in United States and international securities of approximately 77% and 23% , respectively, for 2017 and 71% and 29% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents PacifiCorp's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ — $ 13 $ — $ (4 ) $ 9 Money market mutual funds (2) 21 — — — 21 Investment funds 21 — — — 21 $ 42 $ 13 $ — $ (4 ) $ 51 Liabilities - Commodity derivatives $ — $ (117 ) $ — $ 78 $ (39 ) As of December 31, 2016: Assets: Commodity derivatives $ — $ 27 $ — $ (7 ) $ 20 Money market mutual funds (2) 13 — — — 13 Investment funds 17 — — — 17 $ 30 $ 27 $ — $ (7 ) $ 50 Liabilities - Commodity derivatives $ — $ (104 ) $ — $ 76 $ (28 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $74 million and $69 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents, other current assets and other assets on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying value and estimated fair value of PacifiCorp's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 7,005 $ 8,370 $ 7,052 $ 8,204
MidAmerican Energy Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit pension plan (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ — $ 17 $ — $ 17 Debt securities: United States government obligations 21 — — 21 Corporate obligations — 59 — 59 Municipal obligations — 7 — 7 Agency, asset and mortgage-backed obligations — 33 — 33 Equity securities: United States companies 137 — — 137 International equity securities 44 — — 44 Investment funds (2) 74 — — 74 Total assets in the hierarchy $ 276 $ 116 $ — 392 Investment funds (2) measured at net asset value 315 Real estate funds measured at net asset value 38 Total assets measured at fair value $ 745 As of December 31, 2016: Cash equivalents $ — $ 17 $ — $ 17 Debt securities: United States government obligations 9 — — 9 Corporate obligations — 53 — 53 Municipal obligations — 6 — 6 Agency, asset and mortgage-backed obligations — 22 — 22 Equity securities: United States companies 130 — — 130 International equity securities 39 — — 39 Investment funds (2) 63 — — 63 Total assets in the hierarchy $ 241 $ 98 $ — 339 Investment funds (2) measured at net asset value 295 Real estate funds measured at net asset value 50 Total assets measured at fair value $ 684 (1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 69% and 31% , respectively, for 2017 and 74% and 26% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 72% and 28% , respectively, for 2017 and 71% and 29% , respectively, for 2016 . The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit other postretirement plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 6 $ — $ — $ 6 Debt securities: United States government obligations 5 — — 5 Corporate obligations — 14 — 14 Municipal obligations — 44 — 44 Agency, asset and mortgage-backed obligations — 12 — 12 Equity securities: United States companies 84 — — 84 Investment funds (2) 112 — — 112 Total assets measured at fair value $ 207 $ 70 $ — $ 277 As of December 31, 2016: Cash equivalents $ 10 $ — $ — $ 10 Debt securities: United States government obligations 5 — — 5 Corporate obligations — 11 — 11 Municipal obligations — 37 — 37 Agency, asset and mortgage-backed obligations — 11 — 11 Equity securities: United States companies 122 — — 122 Investment funds (2) 56 — — 56 Total assets measured at fair value $ 193 $ 59 $ — $ 252 (1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 81% and 19% , respectively, for 2017 and 70% and 30% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 42% and 58% , respectively, for 2017 and 30% and 70% , respectively, for 2016 . The following table presents MidAmerican Energy's assets and liabilities recognized on the Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ — $ 3 $ 4 $ (2 ) $ 5 Money market mutual funds (2) 133 — — — 133 Debt securities: United States government obligations 176 — — — 176 International government obligations — 5 — — 5 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Equity securities: United States companies 288 — — — 288 International companies 7 — — — 7 Investment funds 15 — — — 15 $ 619 $ 46 $ 4 $ (2 ) $ 667 Liabilities - commodity derivatives $ — $ (9 ) $ (1 ) $ 2 $ (8 ) As of December 31, 2016 Assets: Commodity derivatives $ — $ 9 $ 1 $ (2 ) $ 8 Money market mutual funds (2) 1 — — — 1 Debt securities: United States government obligations 161 — — — 161 International government obligations — 3 — — 3 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Agency, asset and mortgage-backed obligations — 2 — — 2 Equity securities: United States companies 250 — — — 250 International companies 5 — — — 5 Investment funds 9 — — — 9 $ 426 $ 52 $ 1 $ (2 ) $ 477 Liabilities - commodity derivatives $ — $ (3 ) $ (3 ) $ 3 $ (3 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $- million and $1 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents and investments and restricted cash and investments on the Balance Sheets. The fair value of these money market mutual funds approximates cost.
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table reconciles the beginning and ending balances of MidAmerican Energy's assets measured at fair value on a recurring basis using significant Level 3 inputs for the years ended December 31 (in millions): Commodity Derivatives Auction Rate Securities 2017 2016 2015 2017 2016 2015 Beginning balance $ (2 ) $ (6 ) $ 12 $ — $ 26 $ 26 Transfer to affiliate — (4 ) — — — — Changes included in earnings (1) — — 11 — 5 — Changes in fair value recognized in OCI — — (7 ) — 4 — Changes in fair value recognized in net regulatory assets 2 (6 ) (25 ) — — — Purchases — — 1 — — — Redemptions — — — — (35 ) — Settlements 3 14 2 — — — Ending balance $ 3 $ (2 ) $ (6 ) $ — $ — $ 26 (1) Changes included in earnings related to MidAmerican Energy's unregulated retail services business that was transferred to an affiliate of BHE. Refer to Note 3 for a discussion of discontinued operations. Net unrealized gains included in earnings for the year ended December 31, 2015 , related to commodity derivatives held at December 31, 2015 , totaled $8 million .
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying value and estimated fair value of MidAmerican Energy's long-term debt as of December 31 (in millions): 2017 2016 Carrying Value Fair Value Carrying Value Fair Value Long-term debt $ 5,042 $ 5,686 $ 4,301 $ 4,735
MidAmerican Funding, LLC and Subsidiaries [Domain]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying value and estimated fair value of MidAmerican Funding's long-term debt as of December 31 (in millions): 2017 2016 Carrying Value Fair Value Carrying Value Fair Value Long-term debt $ 5,282 $ 6,006 $ 4,627 $ 5,164
Sierra Pacific Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents Sierra Pacific 's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Total As of December 31, 2017: Assets - investment funds $ — $ — $ — $ — As of December 31, 2016: Assets: Money market mutual funds (1) $ 35 $ — $ — $ 35 Investment funds 1 — — 1 $ 36 $ — $ — $ 36 (1) Amounts are included in cash and cash equivalents on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents the carrying value and estimated fair value of Sierra Pacific 's long-term debt as of December 31 (in millions): 2017 2016 Carrying Fair Carrying Fair Value Value Value Value Long-term debt $ 1,120 $ 1,221 $ 1,119 $ 1,191

Other, Net (Tables)

Other, Net (Tables)	12 Months Ended
	Dec. 31, 2017
MidAmerican Energy Company [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Schedule of Other Nonoperating Income (Expense) [Table Text Block]	Other, net, as shown on the Statements of Operations, includes the following other income (expense) items for the years ended December 31 (in millions): 2017 2016 2015 Corporate-owned life insurance income $ 13 $ 8 $ 4 Gain on redemption of auction rate securities — 5 — Interest income and other, net 6 1 1 Total $ 19 $ 14 $ 5
MidAmerican Funding, LLC and Subsidiaries [Domain]
Component of Other Income (Expense), Nonoperating [Line Items]
Schedule of Other Nonoperating Income (Expense) [Table Text Block]	Other, net, as shown on the Consolidated Statements of Operations, includes the following other income (expense) items for the years ended December 31 (in millions): 2017 2016 2015 Corporate-owned life insurance income $ 13 $ 8 $ 4 Gain on redemption of auction rate securities — 5 — Gains on sales of assets and other investments 1 3 13 Loss on debt tender offer (29 ) — — Interest income and other, net 6 3 2 Total $ (9 ) $ 19 $ 19 Refer to Note 9 for information regarding the debt tender offer. MidAmerican Funding recognized a $13 million pre-tax gain on the sale of an investment in a generating facility lease in 2015.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Components of Income Tax Expense (Benefit) [Table Text Block]	Income tax (benefit) expense consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ (653 ) $ (743 ) $ (929 ) State (3 ) 1 29 Foreign 83 55 84 (573 ) (687 ) (816 ) Deferred: Federal (76 ) 1,164 1,310 State 100 (59 ) (53 ) Foreign 2 (7 ) 17 26 1,098 1,274 Investment tax credits (7 ) (8 ) (8 ) Total $ (554 ) $ 403 $ 450
Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the federal statutory income tax rate to the effective income tax rate applicable to income before income tax (benefit) expense is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Income tax credits (20 ) (14 ) (11 ) State income tax, net of federal income tax benefit 3 (1 ) (1 ) Effects of tax rate change and repatriation tax (31 ) — — Income tax effect of foreign income (5 ) (6 ) (7 ) Equity income (2 ) 2 2 Other, net (2 ) (2 ) (2 ) Effective income tax rate (22 )% 14 % 16 %
Components of Net Deferred Income Tax Liability [Table Text Block]	The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 1,707 $ 909 Federal, state and foreign carryforwards 1,118 987 AROs 223 326 Employee benefits 45 209 Derivative contracts 2 29 Other 448 707 Total deferred income tax assets 3,543 3,167 Valuation allowances (126 ) (64 ) Total deferred income tax assets, net 3,417 3,103 Deferred income tax liabilities: Property-related items (9,950 ) (14,237 ) Investments (843 ) (962 ) Regulatory assets (651 ) (1,449 ) Other (215 ) (334 ) Total deferred income tax liabilities (11,659 ) (16,982 ) Net deferred income tax liability $ (8,242 ) $ (13,879 )
Summary of Operating Loss Carryforwards [Table Text Block]	The following table provides the Company's net operating loss and tax credit carryforwards and expiration dates as of December 31, 2017 (in millions): Federal State Foreign Total Net operating loss carryforwards (1) $ 172 $ 10,813 $ 605 $ 11,590 Deferred income taxes on net operating loss carryforwards $ 37 $ 858 $ 163 $ 1,058 Expiration dates 2023-2025 2018-2037 2035-2037 Tax credits $ 31 $ 29 $ — $ 60 Expiration dates 2023- indefinite 2018- indefinite (1) The federal net operating loss carryforwards relate principally to net operating loss carryforwards of subsidiaries that are tax residents in both the United States and the United Kingdom. The federal net operating loss carryforwards were generated prior to Berkshire Hathaway Inc.'s ownership and will begin to expire in 2023.
Net Unrecognized Tax Benefits Roll Forward [Table Text Block]	A reconciliation of the beginning and ending balances of the Company's net unrecognized tax benefits is as follows for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 128 $ 198 Additions based on tax positions related to the current year 6 7 Additions for tax positions of prior years 70 6 Reductions for tax positions of prior years (18 ) (11 ) Statute of limitations (4 ) (1 ) Settlements (1 ) (67 ) Interest and penalties — (4 ) Ending balance $ 181 $ 128
PacifiCorp [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Components of Income Tax Expense (Benefit) [Table Text Block]	Income tax expense (benefit) consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ 249 $ 169 $ 130 State 41 32 26 Total 290 201 156 Deferred: Federal 59 123 148 State 15 21 29 Total 74 144 177 Investment tax credits (4 ) (5 ) (5 ) Total income tax expense $ 360 $ 340 $ 328
Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the federal statutory income tax rate to the effective income tax rate applicable to income before income tax expense is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % State income taxes, net of federal income tax benefit 3 3 3 Federal income tax credits (5 ) (6 ) (6 ) Other (1 ) (1 ) — Effective income tax rate 32 % 31 % 32 %
Components of Net Deferred Income Tax Liability [Table Text Block]	The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 756 $ 393 Employee benefits 84 202 Derivative contracts and unamortized contract values 48 67 State carryforwards 83 69 Asset retirement obligations 50 78 Other 50 94 1,071 903 Deferred income tax liabilities: Property, plant and equipment (3,381 ) (5,161 ) Regulatory assets (261 ) (586 ) Other (11 ) (36 ) (3,653 ) (5,783 ) Net deferred income tax liability $ (2,582 ) $ (4,880 )
Summary of Operating Loss Carryforwards [Table Text Block]	The following table provides PacifiCorp's net operating loss and tax credit carryforwards and expiration dates as of December 31, 2017 (in millions): State Net operating loss carryforwards $ 1,356 Deferred income taxes on net operating loss carryforwards $ 63 Expiration dates 2018 - 2032 Tax credit carryforwards $ 20 Expiration dates 2018 - indefinite
MidAmerican Energy Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Components of Income Tax Expense (Benefit) [Table Text Block]	MidAmerican Energy's income tax benefit from continuing operations consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ (490 ) $ (479 ) $ (415 ) State (25 ) (14 ) (6 ) (515 ) (493 ) (421 ) Deferred: Federal 335 366 281 State (2 ) (4 ) (6 ) 333 362 275 Investment tax credits (1 ) (1 ) (1 ) Total $ (183 ) $ (132 ) $ (147 )
Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the federal statutory income tax rate to MidAmerican Energy's effective income tax rate applicable to income before income tax benefit from continuing operations is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Income tax credits (68 ) (61 ) (71 ) State income tax, net of federal income tax benefit (4 ) (3 ) (2 ) Effects of ratemaking (7 ) (3 ) (12 ) 2017 Tax Reform 2 — — Other, net (1 ) — 1 Effective income tax rate (43 )% (32 )% (49 )%
Components of Net Deferred Income Tax Liability [Table Text Block]	MidAmerican Energy's net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 443 $ 333 Asset retirement obligations 160 230 Employee benefits 45 66 Other 57 74 Total deferred income tax assets 705 703 Deferred income tax liabilities: Depreciable property (2,865 ) (3,763 ) Regulatory assets (42 ) (471 ) Other (35 ) (41 ) Total deferred income tax liabilities (2,942 ) (4,275 ) Net deferred income tax liability $ (2,237 ) $ (3,572 )
Net Unrecognized Tax Benefits Roll Forward [Table Text Block]	A reconciliation of the beginning and ending balances of MidAmerican Energy's net unrecognized tax benefits is as follows for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 10 $ 10 Additions based on tax positions related to the current year 1 — Additions for tax positions of prior years 23 10 Reductions based on tax positions related to the current year (4 ) (2 ) Reductions for tax positions of prior years (19 ) (8 ) Interest and penalties 1 — Ending balance $ 12 $ 10
MidAmerican Funding, LLC and Subsidiaries [Domain]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Components of Income Tax Expense (Benefit) [Table Text Block]	MidAmerican Funding's income tax benefit from continuing operations consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current: Federal $ (505 ) $ (485 ) $ (418 ) State (31 ) (16 ) (8 ) (536 ) (501 ) (426 ) Deferred: Federal 338 367 282 State (3 ) (4 ) (5 ) 335 363 277 Investment tax credits (1 ) (1 ) (1 ) Total $ (202 ) $ (139 ) $ (150 )
Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the federal statutory income tax rate MidAmerican Funding's the effective income tax rate applicable to income before income tax benefit from continuing operations is as follows for the years ended December 31: 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Income tax credits (77 ) (64 ) (72 ) State income tax, net of federal income tax benefit (6 ) (3 ) (3 ) Effects of ratemaking (8 ) (3 ) (12 ) 2017 Tax Reform 3 — — Other, net (1 ) — 1 Effective income tax rate (54 )% (35 )% (51 )%
Components of Net Deferred Income Tax Liability [Table Text Block]	MidAmerican Funding's net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 443 $ 333 Employee benefits 45 66 Asset retirement obligations 160 230 Other 62 82 Total deferred income tax assets 710 711 Deferred income tax liabilities: Depreciable property (2,868 ) (3,767 ) Regulatory assets (42 ) (471 ) Other (35 ) (41 ) Total deferred income tax liabilities (2,945 ) (4,279 ) Net deferred income tax liability $ (2,235 ) $ (3,568 )
Net Unrecognized Tax Benefits Roll Forward [Table Text Block]	A reconciliation of the beginning and ending balances of MidAmerican Funding's net unrecognized tax benefits is as follows for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 10 $ 10 Additions based on tax positions related to the current year 1 — Additions for tax positions of prior years 23 10 Reductions based on tax positions related to the current year (4 ) (2 ) Reductions for tax positions of prior years (19 ) (8 ) Interest and penalties 1 — Ending balance $ 12 $ 10
Nevada Power Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Components of Income Tax Expense (Benefit) [Table Text Block]	Income tax expense (benefit) consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Current – Federal $ 62 $ 68 $ — Deferred – Federal 95 79 163 Investment tax credits (1 ) (1 ) (1 ) Total income tax expense $ 156 $ 146 $ 162
Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the federal statutory income tax rate to the effective income tax rate applicable to income before income tax expense is as follows for the years ended December 31 : 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Effect of ratemaking 1 — 1 Effect of tax rate change 1 — — Other 1 (1 ) — Effective income tax rate 38 % 34 % 36 %
Components of Net Deferred Income Tax Liability [Table Text Block]	The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 201 $ 83 Capital and financial leases 100 170 Employee benefits 18 29 Customer advances 14 23 Federal net operating loss and credit carryforwards — 5 Other 6 16 Total deferred income tax assets 339 326 Valuation allowance — (5 ) Total deferred income tax assets, net 339 321 Deferred income tax liabilities: Property related items (796 ) (1,293 ) Regulatory assets (206 ) (321 ) Capital and financial leases (97 ) (165 ) Other (7 ) (16 ) Total deferred income tax liabilities (1,106 ) (1,795 ) Net deferred income tax liability $ (767 ) $ (1,474 )
Sierra Pacific Power Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Components of Income Tax Expense (Benefit) [Table Text Block]	Income tax expense (benefit) consists of the following for the years ended December 31 (in millions): 2017 2016 2015 Deferred - Federal $ 56 $ 50 $ 48 Investment tax credits (1 ) (1 ) (1 ) Total income tax expense $ 55 $ 49 $ 47
Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the federal statutory income rate to the effective income tax rate applicable to income before income tax expense is as follows for the years ended December 31 : 2017 2016 2015 Federal statutory income tax rate 35 % 35 % 35 % Effects of ratemaking — 1 1 Effect of tax rate change (1 ) — — Other — 1 — Effective income tax rate 34 % 37 % 36 %
Components of Net Deferred Income Tax Liability [Table Text Block]	The net deferred income tax liability consists of the following as of December 31 (in millions): 2017 2016 Deferred income tax assets: Regulatory liabilities $ 67 $ 16 Federal net operating loss and credit carryforwards 10 25 Employee benefit plans 10 22 Capital and financial leases 7 12 Customer Advances 7 9 Commodity derivative contract — 5 Other 6 6 Total deferred income tax assets 107 95 Deferred income tax liabilities: Property related items (349 ) (562 ) Regulatory assets (74 ) (124 ) Capital and financial leases (7 ) (12 ) Other (7 ) (14 ) Total deferred income tax liabilities (437 ) (712 ) Net deferred income tax liability $ (330 ) $ (617 )
Summary of Operating Loss Carryforwards [Table Text Block]	The following table provides Sierra Pacific 's federal net operating loss and tax credit carryforwards and expiration dates as of December 31 , 2017 (in millions): Net operating loss carryforwards $ 18 Deferred income taxes on federal net operating loss carryforwards $ 4 Expiration dates 2033 Other tax credits $ 6 Expiration dates 2021 - 2032

Supplemental Cash Flow Disclo54

Supplemental Cash Flow Disclosures (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The summary of supplemental cash flow disclosures as of and for the years ending December 31 is as follows (in millions): 2017 2016 2015 Supplemental disclosure of cash flow information: Interest paid, net of amounts capitalized $ 1,715 $ 1,673 $ 1,764 Income taxes received, net (1) $ 540 $ 1,016 $ 1,666 Supplemental disclosure of non-cash investing and financing transactions: Accruals related to property, plant and equipment additions $ 653 $ 547 $ 718 Common stock exchanged for junior subordinated debentures $ 100 $ — $ — (1) Includes $636 million , $1.1 billion and $1.8 billion of income taxes received from Berkshire Hathaway in 2017 , 2016 and 2015 , respectively.
PacifiCorp [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The summary of supplemental cash flow disclosures as of and for the years ended December 31 is as follows (in millions): 2017 2016 2015 Interest paid, net of amounts capitalized $ 350 $ 350 $ 342 Income taxes paid, net $ 340 $ 201 $ 40 Supplemental disclosure of non-cash investing and financing activities: Accounts payable related to property, plant and equipment additions $ 147 $ 101 $ 147 Accounts receivable related to property, plant and equipment sales $ — $ — $ 40
MidAmerican Energy Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The summary of supplemental cash flow disclosures as of and for the years ending December 31 is as follows (in millions): 2017 2016 2015 Supplemental cash flow information: Interest paid, net of amounts capitalized $ 193 $ 181 $ 154 Income taxes received, net $ 465 $ 601 $ 629 Supplemental disclosure of non-cash investing transactions: Accounts payable related to utility plant additions $ 224 $ 131 $ 249 Dividend of unregulated retail services business (Note 3) $ — $ 90 $ —
MidAmerican Funding, LLC and Subsidiaries [Domain]
Condensed Cash Flow Statements, Captions [Line Items]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The summary of supplemental cash flow information as of and for the years ending December 31 is as follows (in millions): 2017 2016 2015 Supplemental cash flow information: Interest paid, net of amounts capitalized $ 218 $ 204 $ 177 Income taxes received, net $ 472 $ 609 $ 630 Supplemental disclosure of non-cash investing transactions: Accounts payable related to utility plant additions $ 224 $ 131 $ 249 Transfer of assets and liabilities to affiliate (Note 3) $ — $ 90 $ —
Nevada Power Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The summary of supplemental cash flow disclosures as of and for the years ended December 31 is as follows (in millions): 2017 2016 2015 Supplemental disclosure of cash flow information - Interest paid, net of amounts capitalized $ 167 $ 173 $ 186 Income taxes paid $ 89 $ — $ — Supplemental disclosure of non-cash investing and financing transactions: Accruals related to property, plant and equipment additions $ 18 $ 19 $ 51 Capital and financial lease obligations incurred $ — $ (1 ) $ (5 )
Sierra Pacific Power Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The summary of supplemental cash flow disclosures as of and for the years ended December 31 is as follows (in millions): 2017 2016 2015 Supplemental disclosure of cash flow information - Interest paid, net of amounts capitalized $ 40 $ 47 $ 54 Supplemental disclosure of non-cash investing and financing transactions: Accruals related to property, plant and equipment additions $ 10 $ 15 $ 24 Capital and financial lease obligations incurred $ 1 $ — $ 13

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	Net periodic benefit cost for the UK Plan included the following components for the years ended December 31 (in millions): 2017 2016 2015 Service cost $ 23 $ 20 $ 24 Interest cost 58 72 79 Expected return on plan assets (100 ) (110 ) (116 ) Settlement 31 — — Net amortization 63 44 62 Net periodic benefit cost $ 75 $ 26 $ 49 Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ 24 $ 29 $ 33 $ 9 $ 9 $ 11 Interest cost 116 126 121 29 31 31 Expected return on plan assets (160 ) (160 ) (169 ) (40 ) (41 ) (45 ) Net amortization 25 46 53 (14 ) (12 ) (11 ) Net periodic benefit cost (credit) $ 5 $ 41 $ 38 $ (16 ) $ (13 ) $ (14 )
Changes in Fair Value of Plan Assets [Table Text Block]	The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, beginning of year $ 2,525 $ 2,489 $ 666 $ 662 Employer contributions 64 78 5 2 Participant contributions — — 10 10 Actual return on plan assets 390 163 106 41 Settlement (15 ) (11 ) — — Benefits paid (203 ) (194 ) (51 ) (49 ) Plan assets at fair value, end of year $ 2,761 $ 2,525 $ 736 $ 666 The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): 2017 2016 Plan assets at fair value, beginning of year $ 2,169 $ 2,276 Employer contributions 58 55 Participant contributions 1 1 Actual return on plan assets 145 349 Settlement (144 ) — Benefits paid (68 ) (115 ) Foreign currency exchange rate changes 207 (397 ) Plan assets at fair value, end of year $ 2,368 $ 2,169
Changes in Projected Benefit Obligations [Table Text Block]	The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Benefit obligation, beginning of year $ 2,952 $ 2,934 $ 734 $ 740 Service cost 24 29 9 9 Interest cost 116 126 29 31 Participant contributions — — 10 10 Actuarial loss (gain) 132 67 (10 ) (7 ) Amendment — 1 — — Settlement (15 ) (11 ) — — Benefits paid (203 ) (194 ) (51 ) (49 ) Benefit obligation, end of year $ 3,006 $ 2,952 $ 721 $ 734 Accumulated benefit obligation, end of year $ 2,988 $ 2,929 following table is a reconciliation of the benefit obligation for the years ended December 31 (in millions): 2017 2016 Benefit obligation, beginning of year $ 2,125 $ 2,142 Service cost 23 20 Interest cost 58 72 Participant contributions 1 1 Actuarial loss (gain) (4 ) 387 Settlement (131 ) — Benefits paid (68 ) (115 ) Foreign currency exchange rate changes 197 (382 ) Benefit obligation, end of year $ 2,201 $ 2,125 Accumulated benefit obligation, end of year $ 1,933 $ 1,858
Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]	The funded status of the plans and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, end of year $ 2,761 $ 2,525 $ 736 $ 666 Benefit obligation, end of year 3,006 2,952 721 734 Funded status $ (245 ) $ (427 ) $ 15 $ (68 ) Amounts recognized on the Consolidated Balance Sheets: Other assets $ 66 $ 26 $ 32 $ 19 Other current liabilities (14 ) (15 ) — — Other long-term liabilities (297 ) (438 ) (17 ) (87 ) Amounts recognized $ (245 ) $ (427 ) $ 15 $ (68 ) The fair value of plan assets, projected benefit obligation and accumulated benefit obligation for (1) pension and other postretirement benefit plans with a projected benefit obligation in excess of the fair value of plan assets and (2) pension plans with an accumulated benefit obligation in excess of the fair value of plan assets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Fair value of plan assets $ 2,016 $ 1,841 $ 126 $ 413 Projected benefit obligation $ 2,327 $ 2,294 $ 143 $ 500 Accumulated benefit obligation $ 2,316 $ 2,278 The funded status of the UK Plan and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): 2017 2016 Plan assets at fair value, end of year $ 2,368 $ 2,169 Benefit obligation, end of year 2,201 2,125 Funded status $ 167 $ 44 Amounts recognized on the Consolidated Balance Sheets: Other assets $ 167 $ 44
Net Periodic Benefit Costs Not Yet Recognized [Table Text Block]	A reconciliation of the amounts not yet recognized as components of net periodic benefit cost, which are included in accumulated other comprehensive loss on the Consolidated Balance Sheets, for the years ended December 31 is as follows (in millions): 2017 2016 Balance, beginning of year $ 590 $ 592 Net (gain) loss arising during the year (50 ) 148 Settlement (17 ) — Net amortization (63 ) (44 ) Foreign currency exchange rate changes 50 (106 ) Total (80 ) (2 ) Balance, end of year $ 510 $ 590 The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Net loss $ 649 $ 775 $ 14 $ 88 Prior service credit (3 ) (7 ) (37 ) (52 ) Regulatory deferrals (4 ) (7 ) 7 7 Total $ 642 $ 761 $ (16 ) $ 43 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2017 and 2016 is as follows (in millions): Accumulated Other Regulatory Regulatory Comprehensive Asset Liability Loss Total Pension Balance, December 31, 2015 $ 729 $ (1 ) $ 13 $ 741 Net loss (gain) arising during the year 76 (11 ) — 65 Net prior service cost arising during the year 1 — — 1 Net amortization (45 ) (1 ) — (46 ) Total 32 (12 ) — 20 Balance, December 31, 2016 761 (13 ) 13 761 Net (gain) loss arising during the year (68 ) (29 ) 3 (94 ) Net amortization (28 ) (1 ) 4 (25 ) Total (96 ) (30 ) 7 (119 ) Balance, December 31, 2017 $ 665 $ (43 ) $ 20 $ 642 Regulatory Regulatory Asset Liability Total Other Postretirement Balance, December 31, 2015 $ 49 $ (12 ) $ 37 Net gain arising during the year (5 ) (1 ) (6 ) Net amortization 11 1 12 Total 6 — 6 Balance, December 31, 2016 55 (12 ) 43 Net gain arising during the year (52 ) (21 ) (73 ) Net amortization 7 7 14 Total (45 ) (14 ) (59 ) Balance, December 31, 2017 $ 10 $ (26 ) $ (16 ) The portion of the funded status of the UK Plan not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): 2017 2016 Net loss $ 510 $ 590
Defined Benefit Plans, Amounts To Be Recognized In Following Year [Table Text Block]	The net loss, prior service credit and regulatory deferrals that will be amortized in 2018 into net periodic benefit cost are estimated to be as follows (in millions): Net Prior Service Regulatory Loss Credit Deferrals Total Pension $ 32 $ (1 ) $ (3 ) $ 28 Other postretirement 1 (15 ) 1 (13 ) Total $ 33 $ (16 ) $ (2 ) $ 15
Plan Assumptions [Table Text Block]	Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost were as follows: Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Benefit obligations as of December 31: Discount rate 3.60 % 4.06 % 4.43 % 3.57 % 4.01 % 4.33 % Rate of compensation increase 2.75 % 2.75 % 2.75 % NA NA NA Net periodic benefit cost for the years ended December 31: Discount rate 4.06 % 4.43 % 4.00 % 4.01 % 4.33 % 3.93 % Expected return on plan assets 6.55 % 6.78 % 6.88 % 6.73 % 7.03 % 7.00 % Rate of compensation increase 2.75 % 2.75 % 2.75 % NA NA NA Assumptions used to determine benefit obligations and net periodic benefit cost were as follows: 2017 2016 2015 Benefit obligations as of December 31: Discount rate 2.60 % 2.70 % 3.70 % Rate of compensation increase 3.45 % 3.00 % 2.90 % Rate of future price inflation 2.95 % 3.00 % 2.90 % Net periodic benefit cost for the years ended December 31: Discount rate 2.70 % 3.70 % 3.60 % Expected return on plan assets 5.00 % 5.60 % 5.60 % Rate of compensation increase 3.00 % 2.90 % 2.80 % Rate of future price inflation 3.00 % 2.90 % 2.80 % In establishing its assumption as to the expected return on plan assets, the Company utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets. 2017 2016 Assumed healthcare cost trend rates as of December 31: Healthcare cost trend rate assumed for next year 7.10 % 7.40 % Rate that the cost trend rate gradually declines to 5.00 % 5.00 % Year that the rate reaches the rate it is assumed to remain at 2025 2025
Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]	A one percentage-point change in assumed healthcare cost trend rates would have the following effects (in millions): One Percentage-Point Increase Decrease Increase (decrease) in: Total service and interest cost for the year ended December 31, 2017 $ — $ — Other postretirement benefit obligation as of December 31, 2017 4 (4 )
Expected Benefit Payments [Table Text Block]	Employer contributions to the UK Plan are expected to be £45 million during 2018 . The expected benefit payments to participants in the UK Plan for 2018 through 2022 and for the five years thereafter excluding lump sum settlement elections, using the foreign currency exchange rate as of December 31, 2017 , are summarized below (in millions): 2018 $ 72 2019 74 2020 75 2021 77 2022 79 2023-2027 427 The expected benefit payments to participants in the Company's pension and other postretirement benefit plans for 2018 through 2022 and for the five years thereafter are summarized below (in millions): Projected Benefit Payments Other Pension Postretirement 2018 $ 226 $ 54 2019 224 55 2020 224 57 2021 222 55 2022 214 54 2023-2027 979 243
Allocation of Plan Assets [Table Text Block]	The target allocations (percentage of plan assets) for the UK Plan assets are as follows as of December 31, 2017 : % Debt securities (1) 50-55 Equity securities (1) 35-40 Real estate funds and other 5-15 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds have been allocated based on the underlying investments in debt and equity securities. The target allocations (percentage of plan assets) for the Company's pension and other postretirement benefit plan assets are as follows as of December 31, 2017 : Other Pension Postretirement % % PacifiCorp: Debt securities (1) 33-38 33-37 Equity securities (1) 49-60 61-65 Limited partnership interests 7-12 1-3 Other 0-1 0-1 MidAmerican Energy: Debt securities (1) 20-50 25-45 Equity securities (1) 60-80 45-80 Real estate funds 2-8 — Other 0-3 0-5 NV Energy: Debt securities (1) 53-77 40 Equity securities (1) 23-47 60 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents the fair value of plan assets, by major category, for the Company's defined benefit pension plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 10 $ 76 $ — $ 86 Debt securities: United States government obligations 218 — — 218 Corporate obligations — 350 — 350 Municipal obligations — 16 — 16 Agency, asset and mortgage-backed obligations — 110 — 110 Equity securities: United States companies 622 — — 622 International companies 136 — — 136 Investment funds (2) 83 20 — 103 Total assets in the fair value hierarchy $ 1,069 $ 572 $ — 1,641 Investment funds (2) measured at net asset value 1,019 Limited partnership interests (3) measured at net asset value 63 Real estate funds measured at net asset value 38 Total assets measured at fair value $ 2,761 As of December 31, 2016: Cash equivalents $ 4 $ 54 $ — $ 58 Debt securities: United States government obligations 161 — — 161 International government obligations — 2 — 2 Corporate obligations — 295 — 295 Municipal obligations — 20 — 20 Agency, asset and mortgage-backed obligations — 112 — 112 Equity securities: United States companies 583 — — 583 International companies 117 — — 117 Investment funds (2) 146 — — 146 Total assets in the fair value hierarchy $ 1,011 $ 483 $ — 1,494 Investment funds (2) measured at net asset value 920 Limited partnership interests (3) measured at net asset value 61 Real estate funds measured at net asset value 50 Total assets measured at fair value $ 2,525 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 62% and 38% , respectively, for both 2017 and 2016 . Additionally, these funds are invested in United States and international securities of approximately 68% and 32% , respectively, for 2017 and 60% and 40% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of plan assets, by major category, for the Company's defined benefit other postretirement plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 11 $ 3 $ — $ 14 Debt securities: United States government obligations 20 — — 20 Corporate obligations — 36 — 36 Municipal obligations — 46 — 46 Agency, asset and mortgage-backed obligations — 29 — 29 Equity securities: United States companies 185 — — 185 International companies 8 — — 8 Investment funds 219 1 — 220 Total assets in the fair value hierarchy $ 443 $ 115 $ — 558 Investment funds measured at net asset value 174 Limited partnership interests measured at net asset value 4 Total assets measured at fair value $ 736 As of December 31, 2016: Cash equivalents $ 18 $ 2 $ — $ 20 Debt securities: United States government obligations 19 — — 19 Corporate obligations — 29 — 29 Municipal obligations — 39 — 39 Agency, asset and mortgage-backed obligations — 25 — 25 Equity securities: United States companies 217 — — 217 International companies 5 — — 5 Investment funds (2) 152 — — 152 Total assets in the fair value hierarchy $ 411 $ 95 $ — 506 Investment funds (2) measured at net asset value 156 Limited partnership interests (3) measured at net asset value 4 Total assets measured at fair value $ 666 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 68% and 32% , respectively, for 2017 and 63% and 37% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 73% and 27% , respectively, for 2017 and 72% and 28% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of the UK Plan assets, by major category (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 4 $ 30 $ — $ 34 Debt securities: United Kingdom government obligations 870 — — 870 Equity securities: Investment funds (2) — 1,027 — 1,027 Real estate funds — — 230 230 Total $ 874 $ 1,057 $ 230 2,161 Investment funds (2) measured at net asset value 207 Total assets measured at fair value $ 2,368 As of December 31, 2016: Cash equivalents $ 4 $ 83 $ — $ 87 Debt securities: United Kingdom government obligations 718 — — 718 Equity securities: Investment funds (2) — 1,095 — 1,095 Real estate funds — — 105 105 Total $ 722 $ 1,178 $ 105 2,005 Investment funds (2) measured at net asset value 164 Total assets measured at fair value $ 2,169 (1) Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 21% and 79% , respectively, for 2017 and 44% and 56% , respectively, for 2016 . The following table presents the Company's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ 1 $ 42 $ 104 $ (29 ) $ 118 Interest rate derivatives — 15 9 — 24 Mortgage loans held for sale — 465 — — 465 Money market mutual funds (2) 685 — — — 685 Debt securities: United States government obligations 176 — — — 176 International government obligations — 5 — — 5 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Equity securities: United States companies 288 — — — 288 International companies 1,968 — — — 1,968 Investment funds 178 — — — 178 $ 3,296 $ 565 $ 113 $ (29 ) $ 3,945 Liabilities: Commodity derivatives $ (3 ) $ (167 ) $ (10 ) $ 105 $ (75 ) Interest rate derivatives — (8 ) — — (8 ) $ (3 ) $ (175 ) $ (10 ) $ 105 $ (83 ) As of December 31, 2016: Assets: Commodity derivatives $ 5 $ 49 $ 87 $ (22 ) $ 119 Interest rate derivatives — 16 7 — 23 Mortgage loans held for sale — 359 — — 359 Money market mutual funds (2) 586 — — — 586 Debt securities: United States government obligations 161 — — — 161 International government obligations — 3 — — 3 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Agency, asset and mortgage-backed obligations — 2 — — 2 Equity securities: United States companies 250 — — — 250 International companies 1,190 — — — 1,190 Investment funds 147 — — — 147 $ 2,339 $ 467 $ 94 $ (22 ) $ 2,878 Liabilities: Commodity derivatives $ (2 ) $ (199 ) $ (27 ) $ 96 $ (132 ) Interest rate derivatives (1 ) (11 ) (1 ) — (13 ) $ (3 ) $ (210 ) $ (28 ) $ 96 $ (145 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $76 million and $74 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
Level Three Defined Benefit Plan Assets Roll Forward [Table Text Block]	The following table reconciles the beginning and ending balances of the UK Plan assets measured at fair value using significant Level 3 inputs for the years ended December 31 (in millions): Real Estate Funds 2017 2016 2015 Beginning balance $ 105 $ 204 $ 199 Actual return on plan assets still held at period end 6 10 18 Purchases (sales) 104 (80 ) — Foreign currency exchange rate changes 15 (29 ) (13 ) Ending balance $ 230 $ 105 $ 204
PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ — $ 4 $ 4 $ 2 $ 2 $ 3 Interest cost 49 54 53 14 15 16 Expected return on plan assets (72 ) (75 ) (77 ) (21 ) (21 ) (23 ) Net amortization 14 34 42 (6 ) (5 ) (4 ) Net periodic benefit cost (credit) $ (9 ) $ 17 $ 22 $ (11 ) $ (9 ) $ (8 )
Changes in Fair Value of Plan Assets [Table Text Block]	The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, beginning of year $ 999 $ 1,043 $ 302 $ 305 Employer contributions 54 5 1 1 Participant contributions — — 7 6 Actual return on plan assets 166 51 49 17 Benefits paid (108 ) (100 ) (27 ) (27 ) Plan assets at fair value, end of year $ 1,111 $ 999 $ 332 $ 302
Changes in Projected Benefit Obligations [Table Text Block]	The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Benefit obligation, beginning of year $ 1,276 $ 1,289 $ 358 $ 362 Service cost — 4 2 2 Interest cost 49 54 14 15 Participant contributions — — 7 6 Actuarial (gain) loss 34 29 (23 ) — Benefits paid (108 ) (100 ) (27 ) (27 ) Benefit obligation, end of year $ 1,251 $ 1,276 $ 331 $ 358 Accumulated benefit obligation, end of year $ 1,251 $ 1,276
Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]	The funded status of the plans and the amounts recognized on the Consolidated Balance Sheets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, end of year $ 1,111 $ 999 $ 332 $ 302 Less - Benefit obligation, end of year 1,251 1,276 331 358 Funded status $ (140 ) $ (277 ) $ 1 $ (56 ) Amounts recognized on the Consolidated Balance Sheets: Other assets $ 5 $ — $ 1 $ — Other current liabilities (4 ) (5 ) — — Other long-term liabilities (141 ) (272 ) — (56 ) Amounts recognized $ (140 ) $ (277 ) $ 1 $ (56 )
Net Periodic Benefit Costs Not Yet Recognized [Table Text Block]	The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Net loss (gain) $ 442 $ 518 $ (12 ) $ 39 Prior service credit — — (6 ) (13 ) Regulatory deferrals (4 ) (7 ) 7 8 Total $ 438 $ 511 $ (11 ) $ 34 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2017 and 2016 is as follows (in millions): Accumulated Other Regulatory Comprehensive Asset Loss Total Pension Balance, December 31, 2015 $ 473 $ 19 $ 492 Net loss arising during the year 51 2 53 Net amortization (33 ) (1 ) (34 ) Total 18 1 19 Balance, December 31, 2016 491 20 511 Net (gain) loss arising during the year (60 ) 1 (59 ) Net amortization (13 ) (1 ) (14 ) Total (73 ) — (73 ) Balance, December 31, 2017 $ 418 $ 20 $ 438 Regulatory Asset (Liability) Other Postretirement Balance, December 31, 2015 $ 26 Net loss arising during the year 3 Net amortization 5 Total 8 Balance, December 31, 2016 34 Net gain arising during the year (51 ) Net amortization 6 Total (45 ) Balance, December 31, 2017 $ (11 )
Defined Benefit Plans, Amounts To Be Recognized In Following Year [Table Text Block]	The net loss, prior service credit and regulatory deferrals that will be amortized in 2018 into net periodic benefit cost are estimated to be as follows (in millions): Net Prior Service Regulatory Loss Credit Deferrals Total Pension $ 16 $ — $ (2 ) $ 14 Other postretirement — (6 ) 1 (5 ) Total $ 16 $ (6 ) $ (1 ) $ 9
Plan Assumptions [Table Text Block]	Assumptions used to determine benefit obligations and net periodic benefit cost were as follows: Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Benefit obligations as of December 31: Discount rate 3.60 % 4.05 % 4.40 % 3.60 % 4.05 % 4.35 % Rate of compensation increase N/A N/A 2.75 N/A N/A N/A Net periodic benefit cost for the years ended December 31: Discount rate 4.05 % 4.40 % 4.00 % 4.05 % 4.35 % 3.99 % Expected return on plan assets 7.25 7.50 7.50 7.25 7.50 7.08 Rate of compensation increase N/A 2.75 2.75 N/A N/A N/A In establishing its assumption as to the expected return on plan assets, PacifiCorp utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets. As a result of a plan amendment effective on January 1, 2017, the benefit obligation for the Retirement Plan is no longer affected by future increases in compensation. As a result of a labor settlement reached with UMWA in December 2014, the benefit obligation for the other postretirement plan is no longer affected by healthcare cost trends.
Expected Benefit Payments [Table Text Block]	The expected benefit payments to participants in PacifiCorp's pension and other postretirement benefit plans for 2018 through 2022 and for the five years thereafter are summarized below (in millions): Projected Benefit Payments Pension Other Postretirement 2018 $ 108 $ 25 2019 107 25 2020 103 26 2021 99 23 2022 94 23 2023-2027 393 100
Allocation of Plan Assets [Table Text Block]	The target allocations (percentage of plan assets) for PacifiCorp's pension and other postretirement benefit plan assets are as follows as of December 31, 2017 : Pension (1) Other Postretirement (1) % % Debt securities (2) 33 - 38 33 - 37 Equity securities (2) 49 - 60 61 - 65 Limited partnership interests 7 - 12 1 - 3 Other 0 - 1 0 - 1 (1) PacifiCorp's Retirement Plan trust includes a separate account that is used to fund benefits for the other postretirement benefit plan. In addition to this separate account, the assets for the other postretirement benefit plan are held in Voluntary Employees' Beneficiary Association ("VEBA") trusts, each of which has its own investment allocation strategies. Target allocations for the other postretirement benefit plan include the separate account of the Retirement Plan trust and the VEBA trusts. (2) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit pension plan (in millions): Input Levels for Fair Value Measurements Level 1 (1) Level 2 (1) Level 3 (1) Total As of December 31, 2017: Cash equivalents $ — $ 43 $ — $ 43 Debt securities: United States government obligations 45 — — 45 Corporate obligations — 60 — 60 Municipal obligations — 9 — 9 Agency, asset and mortgage-backed obligations — 37 — 37 Equity securities: United States companies 416 — — 416 International companies 22 — — 22 Total assets in the fair value hierarchy $ 483 $ 149 $ — 632 Investment funds (2) measured at net asset value 416 Limited partnership interests (3) measured at net asset value 63 Investments at fair value $ 1,111 As of December 31, 2016: Cash equivalents $ — $ 10 $ — $ 10 Debt securities: United States government obligations 25 — — 25 Corporate obligations — 36 — 36 Municipal obligations — 6 — 6 Agency, asset and mortgage-backed obligations — 37 — 37 Equity securities: United States companies 389 — — 389 International companies 15 — — 15 Investment funds (2) 83 — — 83 Total assets in the fair value hierarchy $ 512 $ 89 $ — 601 Investment funds (2) measured at net asset value 337 Limited partnership interests (3) measured at net asset value 61 Investments at fair value $ 999 (1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 60% and 40% respectively, for 2017 and 54% and 46% , respectively, for 2016 , and are invested in United States and international securities of approximately 57% and 43% , respectively, for 2017 and 39% and 61% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents the fair value of plan assets, by major category, for PacifiCorp's defined benefit other postretirement plan (in millions): Input Levels for Fair Value Measurements Level 1 (1) Level 2 (1) Level 3 (1) Total As of December 31, 2017: Cash and cash equivalents $ 4 $ 3 $ — $ 7 Debt securities: United States government obligations 11 — — 11 Corporate obligations — 16 — 16 Municipal obligations — 2 — 2 Agency, asset and mortgage-backed obligations — 16 — 16 Equity securities: United States companies 98 — — 98 International companies 6 — — 6 Investment funds (2) 32 — — 32 Total assets in the fair value hierarchy $ 151 $ 37 $ — 188 Investment funds (2) measured at net asset value 140 Limited partnership interests (3) measured at net asset value 4 Investments at fair value $ 332 As of December 31, 2016: Cash and cash equivalents $ 4 $ 1 $ — $ 5 Debt securities: United States government obligations 11 — — 11 Corporate obligations — 13 — 13 Municipal obligations — 2 — 2 Agency, asset and mortgage-backed obligations — 13 — 13 Equity securities: United States companies 93 — — 93 International companies 4 — — 4 Investment funds (2) 32 — — 32 Total assets in the fair value hierarchy $ 144 $ 29 $ — 173 Investment funds (2) measured at net asset value 125 Limited partnership interests (3) measured at net asset value 4 Investments at fair value $ 302 (1) Refer to Note 12 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 63% and 37% , respectively, for 2017 and 62% and 38% , respectively, for 2016 , and are invested in United States and international securities of approximately 77% and 23% , respectively, for 2017 and 71% and 29% , respectively, for 2016 . (3) Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital. The following table presents PacifiCorp's assets and liabilities recognized on the Consolidated Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ — $ 13 $ — $ (4 ) $ 9 Money market mutual funds (2) 21 — — — 21 Investment funds 21 — — — 21 $ 42 $ 13 $ — $ (4 ) $ 51 Liabilities - Commodity derivatives $ — $ (117 ) $ — $ 78 $ (39 ) As of December 31, 2016: Assets: Commodity derivatives $ — $ 27 $ — $ (7 ) $ 20 Money market mutual funds (2) 13 — — — 13 Investment funds 17 — — — 17 $ 30 $ 27 $ — $ (7 ) $ 50 Liabilities - Commodity derivatives $ — $ (104 ) $ — $ 76 $ (28 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $74 million and $69 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents, other current assets and other assets on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
Schedule of Multiemployer Plans [Table Text Block]	The following table presents PacifiCorp's and Energy West Mining Company's participation in individually significant joint trustee and multiemployer pension plans for the years ended December 31 (dollars in millions): PPA zone status or plan funded status percentage for plan years beginning July 1, Contributions (1) Plan name Employer Identification Number 2017 2016 2015 Funding improvement plan Surcharge imposed under PPA (1) 2017 2016 2015 Year contributions to plan exceeded more than 5% of total contributions (2) UMWA 1974 Pension Plan 52-1050282 Critical and Declining Critical and Declining Critical and Declining Implemented Yes $ — $ — $ 1 None Local 57 Trust Fund 87-0640888 At least 80% At least 80% At least 80% None None $ 7 $ 8 $ 8 2015, 2014, 2013 (1) PacifiCorp's and Energy West Mining Company's minimum contributions to the plans are based on the amount of wages paid to employees covered by the Local 57 Trust Fund collective bargaining agreements and the number of mining hours worked for the UMWA 1974 Pension Plan, respectively, subject to ERISA minimum funding requirements. As a result of the plan's critical status, Energy West Mining Company was required to begin paying a surcharge for hours worked on and after December 1, 2014. (2) For the UMWA 1974 Pension Plan, information is for plan years beginning July 1, 2015, 2014 and 2013. Information for the plan year beginning July 1, 2016 is not yet available. For the Local 57 Trust Fund, information is for plan years beginning July 1, 2015, 2014 and 2013. Information for the plan year beginning July 1, 2016 is not yet available.
MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	Net periodic benefit cost for the plans of MidAmerican Energy and the aforementioned affiliates included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ 9 $ 10 $ 12 $ 5 $ 5 $ 7 Interest cost 31 34 32 9 10 9 Expected return on plan assets (44 ) (44 ) (46 ) (14 ) (13 ) (15 ) Net amortization 2 2 2 (4 ) (4 ) (3 ) Net periodic benefit (credit) cost $ (2 ) $ 2 $ — $ (4 ) $ (2 ) $ (2 )
Changes in Fair Value of Plan Assets [Table Text Block]	The following table is a reconciliation of the fair value of plan assets for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, beginning of year $ 684 $ 678 $ 252 $ 249 Employer contributions 7 7 1 1 Participant contributions — — 1 1 Actual return on plan assets 114 57 36 14 Benefits paid (60 ) (58 ) (13 ) (13 ) Plan assets at fair value, end of year $ 745 $ 684 $ 277 $ 252
Changes in Projected Benefit Obligations [Table Text Block]	The following table is a reconciliation of the benefit obligations for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2017 2016 Benefit obligation, beginning of year $ 773 $ 785 $ 233 $ 234 Service cost 9 10 5 5 Interest cost 31 34 9 10 Participant contributions — — 1 1 Actuarial loss (gain) 46 2 11 (4 ) Benefits paid (60 ) (58 ) (13 ) (13 ) Benefit obligation, end of year $ 799 $ 773 $ 246 $ 233 Accumulated benefit obligation, end of year $ 790 $ 764
Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]	The funded status of the plans and the amounts recognized on the Balance Sheets as of December 31 are as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Plan assets at fair value, end of year $ 745 $ 684 $ 277 $ 252 Less - Benefit obligation, end of year 799 773 246 233 Funded status $ (54 ) $ (89 ) $ 31 $ 19 Amounts recognized on the Balance Sheets: Other assets $ 66 $ 26 $ 31 $ 19 Other current liabilities (8 ) (8 ) — — Other liabilities (112 ) (107 ) — — Amounts recognized $ (54 ) $ (89 ) $ 31 $ 19
Net Periodic Benefit Costs Not Yet Recognized [Table Text Block]	The portion of the funded status of the plans not yet recognized in net periodic benefit cost as of December 31 is as follows (in millions): Pension Other Postretirement 2017 2016 2017 2016 Net (gain) loss $ (11 ) $ 15 $ 23 $ 36 Prior service cost (credit) 1 1 (25 ) (31 ) Total $ (10 ) $ 16 $ (2 ) $ 5 A reconciliation of the amounts not yet recognized as components of net periodic benefit cost for the years ended December 31, 2017 and 2016 is as follows (in millions): Regulatory Asset Regulatory Liability Receivables (Payables) with Affiliates Total Pension Balance, December 31, 2015 $ 22 $ — $ 6 $ 28 Net loss (gain) arising during the year 1 (11 ) — (10 ) Net amortization (1 ) (1 ) — (2 ) Total — (12 ) — (12 ) Balance, December 31, 2016 22 (12 ) 6 16 Net loss (gain) arising during the year 4 (29 ) 1 (24 ) Net amortization (2 ) — — (2 ) Total 2 (29 ) 1 (26 ) Balance, December 31, 2017 $ 24 $ (41 ) $ 7 $ (10 ) Regulatory Asset Receivables (Payables) with Affiliates Total Other Postretirement Balance, December 31, 2015 $ 17 $ (11 ) $ 6 Net gain arising during the year (2 ) (3 ) (5 ) Net amortization 3 1 4 Total 1 (2 ) (1 ) Balance, December 31, 2016 18 (13 ) 5 Net gain arising during the year (7 ) (4 ) (11 ) Net amortization 3 1 4 Total (4 ) (3 ) (7 ) Balance, December 31, 2017 $ 14 $ (16 ) $ (2 )
Defined Benefit Plans, Amounts To Be Recognized In Following Year [Table Text Block]	The net loss and prior service cost (credit) that will be amortized in 2018 into net periodic benefit cost are estimated to be as follows (in millions): Net Loss Prior Service Cost (Credit) Total Pension $ 1 $ 1 $ 2 Other postretirement 1 (5 ) (4 ) Total $ 2 $ (4 ) $ (2 )
Plan Assumptions [Table Text Block]	Assumptions used to determine benefit obligations and net periodic benefit cost were as follows: Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Benefit obligations as of December 31: Discount rate 3.60 % 4.10 % 4.50 % 3.50 % 3.90 % 4.25 % Rate of compensation increase 2.75 % 2.75 % 2.75 % N/A N/A N/A Net periodic benefit cost for the years ended December 31: Discount rate 4.10 % 4.50 % 4.00 % 3.90 % 4.25 % 3.75 % Expected return on plan assets (1) 6.75 % 7.00 % 7.25 % 6.50 % 6.75 % 7.00 % Rate of compensation increase 2.75 % 2.75 % 2.75 % N/A N/A N/A (1) Amounts reflected are pre-tax values. Assumed after-tax returns for a taxable, non-union other postretirement plan were 4.81% for 2017 , and 5.00% for 2016 , and 5.18% for 2015 . In establishing its assumption as to the expected return on plan assets, MidAmerican Energy utilizes the asset allocation and return assumptions for each asset class based on historical performance and forward-looking views of the financial markets. 2017 2016 Assumed healthcare cost trend rates as of December 31: Healthcare cost trend rate assumed for next year 7.10 % 7.40 % Rate that the cost trend rate gradually declines to 5.00 % 5.00 % Year that the rate reaches the rate it is assumed to remain at 2025 2025
Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]	A one percentage-point change in assumed healthcare cost trend rates would have the following effects (in millions): One Percentage-Point Increase Decrease Increase (decrease) in: Total service and interest cost for the year ended December 31, 2017 $ — $ — Other postretirement benefit obligation as of December 31, 2017 3 (3 )
Expected Benefit Payments [Table Text Block]	Net periodic benefit costs assigned to MidAmerican Energy affiliates are reimbursed currently in accordance with its intercompany administrative services agreement. The expected benefit payments to participants in MidAmerican Energy's pension and other postretirement benefit plans for 2017 through 2021 and for the five years thereafter are summarized below (in millions): Projected Benefit Payments Pension Other Postretirement 2018 $ 60 $ 19 2019 61 20 2020 60 21 2021 59 22 2022 57 21 2023-2027 256 98
Allocation of Plan Assets [Table Text Block]	The target allocations (percentage of plan assets) for MidAmerican Energy's pension and other postretirement benefit plan assets are as follows as of December 31, 2017 : Pension Other Postretirement % % Debt securities (1) 20-50 25-45 Equity securities (1) 60-80 45-80 Real estate funds 2-8 — Other 0-3 0-5 (1) For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.
Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit pension plan (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ — $ 17 $ — $ 17 Debt securities: United States government obligations 21 — — 21 Corporate obligations — 59 — 59 Municipal obligations — 7 — 7 Agency, asset and mortgage-backed obligations — 33 — 33 Equity securities: United States companies 137 — — 137 International equity securities 44 — — 44 Investment funds (2) 74 — — 74 Total assets in the hierarchy $ 276 $ 116 $ — 392 Investment funds (2) measured at net asset value 315 Real estate funds measured at net asset value 38 Total assets measured at fair value $ 745 As of December 31, 2016: Cash equivalents $ — $ 17 $ — $ 17 Debt securities: United States government obligations 9 — — 9 Corporate obligations — 53 — 53 Municipal obligations — 6 — 6 Agency, asset and mortgage-backed obligations — 22 — 22 Equity securities: United States companies 130 — — 130 International equity securities 39 — — 39 Investment funds (2) 63 — — 63 Total assets in the hierarchy $ 241 $ 98 $ — 339 Investment funds (2) measured at net asset value 295 Real estate funds measured at net asset value 50 Total assets measured at fair value $ 684 (1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 69% and 31% , respectively, for 2017 and 74% and 26% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 72% and 28% , respectively, for 2017 and 71% and 29% , respectively, for 2016 . The following table presents the fair value of plan assets, by major category, for MidAmerican Energy's defined benefit other postretirement plans (in millions): Input Levels for Fair Value Measurements (1) Level 1 Level 2 Level 3 Total As of December 31, 2017: Cash equivalents $ 6 $ — $ — $ 6 Debt securities: United States government obligations 5 — — 5 Corporate obligations — 14 — 14 Municipal obligations — 44 — 44 Agency, asset and mortgage-backed obligations — 12 — 12 Equity securities: United States companies 84 — — 84 Investment funds (2) 112 — — 112 Total assets measured at fair value $ 207 $ 70 $ — $ 277 As of December 31, 2016: Cash equivalents $ 10 $ — $ — $ 10 Debt securities: United States government obligations 5 — — 5 Corporate obligations — 11 — 11 Municipal obligations — 37 — 37 Agency, asset and mortgage-backed obligations — 11 — 11 Equity securities: United States companies 122 — — 122 Investment funds (2) 56 — — 56 Total assets measured at fair value $ 193 $ 59 $ — $ 252 (1) Refer to Note 14 for additional discussion regarding the three levels of the fair value hierarchy. (2) Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 81% and 19% , respectively, for 2017 and 70% and 30% , respectively, for 2016 . Additionally, these funds are invested in United States and international securities of approximately 42% and 58% , respectively, for 2017 and 30% and 70% , respectively, for 2016 . The following table presents MidAmerican Energy's assets and liabilities recognized on the Balance Sheets and measured at fair value on a recurring basis (in millions): Input Levels for Fair Value Measurements Level 1 Level 2 Level 3 Other (1) Total As of December 31, 2017: Assets: Commodity derivatives $ — $ 3 $ 4 $ (2 ) $ 5 Money market mutual funds (2) 133 — — — 133 Debt securities: United States government obligations 176 — — — 176 International government obligations — 5 — — 5 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Equity securities: United States companies 288 — — — 288 International companies 7 — — — 7 Investment funds 15 — — — 15 $ 619 $ 46 $ 4 $ (2 ) $ 667 Liabilities - commodity derivatives $ — $ (9 ) $ (1 ) $ 2 $ (8 ) As of December 31, 2016 Assets: Commodity derivatives $ — $ 9 $ 1 $ (2 ) $ 8 Money market mutual funds (2) 1 — — — 1 Debt securities: United States government obligations 161 — — — 161 International government obligations — 3 — — 3 Corporate obligations — 36 — — 36 Municipal obligations — 2 — — 2 Agency, asset and mortgage-backed obligations — 2 — — 2 Equity securities: United States companies 250 — — — 250 International companies 5 — — — 5 Investment funds 9 — — — 9 $ 426 $ 52 $ 1 $ (2 ) $ 477 Liabilities - commodity derivatives $ — $ (3 ) $ (3 ) $ 3 $ (3 ) (1) Represents netting under master netting arrangements and a net cash collateral receivable of $- million and $1 million as of December 31, 2017 and 2016 , respectively. (2) Amounts are included in cash and cash equivalents and investments and restricted cash and investments on the Balance Sheets. The fair value of these money market mutual funds approximates cost.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	Pension and postretirement costs allocated by MidAmerican Funding to its parent and other affiliates in each of the years ended December 31, were as follows (in millions): 2017 2016 2015 Pension costs $ 4 $ 4 $ 4 Other postretirement costs (3 ) (1 ) (2 )

Retirement Plan and Postretir56

Retirement Plan and Postretirement Benefits Retirement Plan and Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	Net periodic benefit cost for the UK Plan included the following components for the years ended December 31 (in millions): 2017 2016 2015 Service cost $ 23 $ 20 $ 24 Interest cost 58 72 79 Expected return on plan assets (100 ) (110 ) (116 ) Settlement 31 — — Net amortization 63 44 62 Net periodic benefit cost $ 75 $ 26 $ 49 Net periodic benefit cost for the plans included the following components for the years ended December 31 (in millions): Pension Other Postretirement 2017 2016 2015 2017 2016 2015 Service cost $ 24 $ 29 $ 33 $ 9 $ 9 $ 11 Interest cost 116 126 121 29 31 31 Expected return on plan assets (160 ) (160 ) (169 ) (40 ) (41 ) (45 ) Net amortization 25 46 53 (14 ) (12 ) (11 ) Net periodic benefit cost (credit) $ 5 $ 41 $ 38 $ (16 ) $ (13 ) $ (14 )
Nevada Power Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Amounts Recognized in Balance Sheet [Table Text Block]	Amounts receivable from (payable to) NV Energy are included on the Consolidated Balance Sheets and consist of the following as of December 31 (in millions): 2017 2016 Qualified Pension Plan - Other long-term liabilities $ (23 ) $ (24 ) Non-Qualified Pension Plans: Other current liabilities (1 ) (1 ) Other long-term liabilities (10 ) (9 ) Other Postretirement Plans - Other long-term liabilities 1 (4 )
Sierra Pacific Power Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Amounts Recognized in Balance Sheet [Table Text Block]	Amounts payable to NV Energy are included on the Consolidated Balance Sheets and consist of the following as of December 31 (in millions): 2017 2016 Qualified Pension Plan - Other long-term liabilities $ (2 ) $ (12 ) Non-Qualified Pension Plans: Other current liabilities (1 ) (1 ) Other long-term liabilities (8 ) (9 ) Other Postretirement Plans - Other long-term liabilities (20 ) (28 )

Asset Retirement Oblilgations (

Asset Retirement Oblilgations (Tables)	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations By Type [Table Text Block]	The following table presents the Company's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Fossil fuel facilities $ 380 $ 404 Quad Cities Station 342 343 Wind generating facilities 138 124 Offshore pipeline facilities 32 33 Solar generating facilities 19 12 Other 43 38 Total asset retirement obligations $ 954 $ 954 Quad Cities Station nuclear decommissioning trust funds $ 515 $ 460
Asset Retirement Obligation Disclosure [Table Text Block]	The following table reconciles the beginning and ending balances of the Company's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 954 $ 921 Change in estimated costs (18 ) 33 Additions 21 25 Retirements (45 ) (63 ) Accretion 42 38 Ending balance $ 954 $ 954 Reflected as: Other current liabilities $ 60 $ 98 Other long-term liabilities 894 856 Total ARO liability $ 954 $ 954
PacifiCorp [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligation Disclosure [Table Text Block]	The following table reconciles the beginning and ending balances of PacifiCorp's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 215 $ 224 Change in estimated costs (8 ) 2 Additions 6 — Retirements (6 ) (19 ) Accretion 8 8 Ending balance $ 215 $ 215 Reflected as: Other current liabilities $ 25 $ 21 Other long-term liabilities 190 194 $ 215 $ 215
MidAmerican Energy Company [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations By Type [Table Text Block]	The following table presents MidAmerican Energy's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Quad Cities Station $ 342 $ 343 Fossil-fueled generating facilities 113 132 Wind-powered generating facilities 103 91 Other 1 1 Total asset retirement obligations $ 559 $ 567 Quad Cities Station nuclear decommissioning trust funds (1) $ 515 $ 460 (1) Refer to Note 7 for a discussion of the Quad Cities Station nuclear decommissioning trust funds.
Asset Retirement Obligation Disclosure [Table Text Block]	The following table reconciles the beginning and ending balances of MidAmerican Energy's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 567 $ 532 Change in estimated costs (14 ) 28 Additions 8 14 Retirements (26 ) (32 ) Accretion 24 25 Ending balance $ 559 $ 567 Reflected as: Other current liabilities $ 31 $ 57 Asset retirement obligations 528 510 $ 559 $ 567
Nevada Power Company [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations By Type [Table Text Block]	The following table presents Nevada Power 's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Waste water remediation $ 39 $ 38 Evaporative ponds and dry ash landfills 11 22 Asbestos 3 4 Solar 3 2 Other 24 17 Total asset retirement obligations $ 80 $ 83
Asset Retirement Obligation Disclosure [Table Text Block]	The following table reconciles the beginning and ending balances of Nevada Power 's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 83 $ 85 Change in estimated costs 6 4 Retirements (13 ) (10 ) Accretion 4 4 Ending balance $ 80 $ 83 Reflected as: Other current liabilities $ 4 $ 20 Other long-term liabilities 76 63 $ 80 $ 83
Sierra Pacific Power Company [Member]
Asset Retirement Obligations Disclosure [Line Items]
Asset Retirement Obligations By Type [Table Text Block]	The following table presents Sierra Pacific 's ARO liabilities by asset type as of December 31 (in millions): 2017 2016 Asbestos $ 5 $ 4 Evaporative ponds and dry ash landfills 2 3 Other 3 3 Total asset retirement obligations $ 10 $ 10
Asset Retirement Obligation Disclosure [Table Text Block]	The following table reconciles the beginning and ending balances of Sierra Pacific 's ARO liabilities for the years ended December 31 (in millions): 2017 2016 Beginning balance $ 10 $ 10 Retirements — — Ending balance $ 10 $ 10 Reflected as: Other current liabilities $ — $ — Other long-term liabilities 10 10 $ 10 $ 10

Commitments and Contingencies58

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Contractual Obligation [Line Items]
Contractual Obligation, Fiscal Year Maturity Schedule	The Company has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31, 2017 are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total Contract type: Fuel, capacity and transmission contract commitments $ 2,098 $ 1,637 $ 1,435 $ 1,210 $ 1,055 $ 10,044 $ 17,479 Construction commitments 1,120 57 5 — — — 1,182 Operating leases and easements 180 157 141 121 111 1,297 2,007 Maintenance, service and other contracts 246 249 238 231 253 1,055 2,272 $ 3,644 $ 2,100 $ 1,819 $ 1,562 $ 1,419 $ 12,396 $ 22,940
PacifiCorp [Member]
Contractual Obligation [Line Items]
Contractual Obligation, Fiscal Year Maturity Schedule	PacifiCorp has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31, 2017 are as follows (in millions): 2018 2019 2020 2021 2022 2023 and Thereafter Total Contract type: Purchased electricity contracts - commercially operable $ 276 $ 165 $ 161 $ 150 $ 145 $ 1,574 $ 2,471 Purchased electricity contracts - non-commercially operable 9 18 26 26 27 451 557 Fuel contracts 695 619 591 453 337 1,268 3,963 Construction commitments 85 29 3 — — — 117 Transmission 112 96 66 49 39 428 790 Operating leases and easements 7 7 7 7 6 97 131 Maintenance, service and other contracts 36 34 22 25 14 80 211 Total commitments $ 1,220 $ 968 $ 876 $ 710 $ 568 $ 3,898 $ 8,240
MidAmerican Energy Company [Member]
Contractual Obligation [Line Items]
Contractual Obligation, Fiscal Year Maturity Schedule	MidAmerican Energy had the following firm commitments that are not reflected on the Balance Sheet. Minimum payments as of December 31, 2017 , are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total Contract type: Coal and natural gas for generation $ 112 $ 56 $ 12 $ 9 $ 8 $ — $ 197 Electric capacity and transmission 34 31 31 27 16 43 182 Natural gas contracts for gas operations 122 75 73 57 42 42 411 Construction commitments 790 28 2 — — — 820 Easements and operating leases 22 21 21 21 21 713 819 Maintenance and services contracts 96 102 119 114 154 233 818 $ 1,176 $ 313 $ 258 $ 228 $ 241 $ 1,031 $ 3,247
Nevada Power Company [Member]
Contractual Obligation [Line Items]
Contractual Obligation, Fiscal Year Maturity Schedule	Nevada Power has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31 , 2017 are as follows (in millions): 2018 2019 2020 2021 2022 2023 and Thereafter Total Contract type: Fuel, capacity and transmission contract commitments $ 591 $ 450 $ 377 $ 378 $ 380 $ 5,208 $ 7,384 Fuel and capacity contract commitments (not commercially operable) — 15 22 24 25 421 507 Operating leases and easements 7 7 8 8 7 54 91 Maintenance, service and other contracts 46 44 43 39 37 40 249 Total commitments $ 644 $ 516 $ 450 $ 449 $ 449 $ 5,723 $ 8,231
Sierra Pacific Power Company [Member]
Contractual Obligation [Line Items]
Contractual Obligation, Fiscal Year Maturity Schedule	Sierra Pacific has the following firm commitments that are not reflected on the Consolidated Balance Sheet. Minimum payments as of December 31 , 2017 are as follows (in millions): 2023 and 2018 2019 2020 2021 2022 Thereafter Total Contract type: Fuel, capacity and transmission contract commitments $ 200 $ 155 $ 114 $ 74 $ 71 $ 515 $ 1,129 Fuel and capacity contract commitments (not commercially operable) — 7 17 22 22 590 658 Operating leases and easements 4 4 4 3 2 54 71 Maintenance, service and other contracts 6 6 6 7 5 12 42 Total commitments $ 210 $ 172 $ 141 $ 106 $ 100 $ 1,171 $ 1,900

Components of Accumulated Oth59

Components of Accumulated Other Comprehensive Loss, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of accumulated other comprehensive income (loss)
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table shows the change in accumulated other comprehensive loss attributable to BHE shareholders by each component of other comprehensive income (loss), net of applicable income taxes, for the year ended December 31 (in millions): Accumulated Unrealized Other Unrecognized Foreign Gains on Unrealized Comprehensive Amounts on Currency Available- Gains on Loss Attributable Retirement Translation For-Sale Cash Flow To BHE Benefits Adjustment Securities Hedges Shareholders, Net Balance, December 31, 2014 $ (490 ) $ (412 ) $ 390 $ 18 $ (494 ) Other comprehensive income (loss) 52 (680 ) 225 (11 ) (414 ) Balance, December 31, 2015 (438 ) (1,092 ) 615 7 (908 ) Other comprehensive income (loss) (9 ) (583 ) (30 ) 19 (603 ) Balance, December 31, 2016 (447 ) (1,675 ) 585 26 (1,511 ) Other comprehensive income (loss) 64 546 500 3 1,113 Balance, December 31, 2017 $ (383 ) $ (1,129 ) $ 1,085 $ 29 $ (398 )
MidAmerican Energy Company [Member]
Schedule of accumulated other comprehensive income (loss)
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table shows the change in accumulated other comprehensive loss by each component of other comprehensive income, net of applicable income taxes, for the year ended December 31, 2016 (in millions): Unrealized Unrealized Accumulated Losses on Losses Other Available-For-Sale on Cash Flow Comprehensive Securities Hedges Loss, Net Balance, December 31, 2015 $ (3 ) $ (27 ) $ (30 ) Other comprehensive income 3 — 3 Dividend (Note 3) — 27 27 Balance, December 31, 2016 $ — $ — $ —

Noncontrolling Interests Noncon

Noncontrolling Interests Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2017
MidAmerican Funding, LLC and Subsidiaries [Domain]
Noncontrolling Interest [Line Items]
Schedule of Other Nonoperating Income (Expense) [Table Text Block]	Other, net, as shown on the Consolidated Statements of Operations, includes the following other income (expense) items for the years ended December 31 (in millions): 2017 2016 2015 Corporate-owned life insurance income $ 13 $ 8 $ 4 Gain on redemption of auction rate securities — 5 — Gains on sales of assets and other investments 1 3 13 Loss on debt tender offer (29 ) — — Interest income and other, net 6 3 2 Total $ (9 ) $ 19 $ 19 Refer to Note 9 for information regarding the debt tender offer. MidAmerican Funding recognized a $13 million pre-tax gain on the sale of an investment in a generating facility lease in 2015.

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting Information [Line Items]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Information related to the Company's reportable segments is shown below (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: PacifiCorp $ 5,237 $ 5,201 $ 5,232 MidAmerican Funding 2,846 2,631 2,515 NV Energy 3,015 2,895 3,351 Northern Powergrid 949 995 1,140 BHE Pipeline Group 993 978 1,016 BHE Transmission 699 502 592 BHE Renewables 838 743 728 HomeServices 3,443 2,801 2,526 BHE and Other (1) 594 676 780 Total operating revenue $ 18,614 $ 17,422 $ 17,880 Depreciation and amortization: PacifiCorp $ 796 $ 783 $ 780 MidAmerican Funding 500 479 407 NV Energy 422 421 410 Northern Powergrid 214 200 202 BHE Pipeline Group 159 206 204 BHE Transmission 239 241 185 BHE Renewables 251 230 216 HomeServices 66 31 29 BHE and Other (1) (1 ) — (5 ) Total depreciation and amortization $ 2,646 $ 2,591 $ 2,428 Operating income: PacifiCorp $ 1,462 $ 1,427 $ 1,344 MidAmerican Funding 562 566 451 NV Energy 765 770 812 Northern Powergrid 436 494 593 BHE Pipeline Group 475 455 464 BHE Transmission 322 92 260 BHE Renewables 316 256 255 HomeServices 214 212 184 BHE and Other (1) (38 ) (21 ) (35 ) Total operating income 4,514 4,251 4,328 Interest expense (1,841 ) (1,854 ) (1,904 ) Capitalized interest 45 139 74 Allowance for equity funds 76 158 91 Interest and dividend income 111 120 107 Other, net (398 ) 36 39 Total income before income tax (benefit) expense and equity (loss) income $ 2,507 $ 2,850 $ 2,735 Years Ended December 31, 2017 2016 2015 Interest expense: PacifiCorp $ 381 $ 381 $ 383 MidAmerican Funding 237 218 206 NV Energy 233 250 262 Northern Powergrid 133 136 145 BHE Pipeline Group 43 50 66 BHE Transmission 169 153 146 BHE Renewables 204 198 193 HomeServices 7 2 3 BHE and Other (1) 434 466 500 Total interest expense $ 1,841 $ 1,854 $ 1,904 Income tax (benefit) expense: PacifiCorp $ 362 $ 341 $ 328 MidAmerican Funding (202 ) (139 ) (150 ) NV Energy 221 200 207 Northern Powergrid 57 22 35 BHE Pipeline Group 170 163 158 BHE Transmission (124 ) 26 63 BHE Renewables (2) (795 ) (32 ) 41 HomeServices 49 81 72 BHE and Other (1) (292 ) (259 ) (304 ) Total income tax (benefit) expense $ (554 ) $ 403 $ 450 Capital expenditures: PacifiCorp $ 769 $ 903 $ 916 MidAmerican Funding 1,776 1,637 1,448 NV Energy 456 529 571 Northern Powergrid 579 579 674 BHE Pipeline Group 286 226 240 BHE Transmission 334 466 966 BHE Renewables 323 719 1,034 HomeServices 37 20 16 BHE and Other 11 11 10 Total capital expenditures $ 4,571 $ 5,090 $ 5,875 As of December 31, 2017 2016 2015 Property, plant and equipment, net: PacifiCorp $ 19,203 $ 19,162 $ 19,039 MidAmerican Funding 14,221 12,835 11,737 NV Energy 9,770 9,825 9,767 Northern Powergrid 6,075 5,148 5,790 BHE Pipeline Group 4,587 4,423 4,345 BHE Transmission 6,330 5,810 5,301 BHE Renewables 5,637 5,302 4,805 HomeServices 117 78 70 BHE and Other (69 ) (74 ) (85 ) Total property, plant and equipment, net $ 65,871 $ 62,509 $ 60,769 Total assets: PacifiCorp $ 23,086 $ 23,563 $ 23,550 MidAmerican Funding 18,444 17,571 16,315 NV Energy 13,903 14,320 14,656 Northern Powergrid 7,565 6,433 7,317 BHE Pipeline Group 5,134 5,144 4,953 BHE Transmission 9,009 8,378 7,553 BHE Renewables 7,687 7,010 5,892 HomeServices 2,722 1,776 1,705 BHE and Other 2,658 1,245 1,677 Total assets $ 90,208 $ 85,440 $ 83,618 Years Ended December 31, 2017 2016 2015 Operating revenue by country: United States $ 16,916 $ 15,895 $ 16,121 United Kingdom 948 995 1,140 Canada 699 506 600 Philippines and other 51 26 19 Total operating revenue by country $ 18,614 $ 17,422 $ 17,880 Income before income tax (benefit) expense and equity (loss) income by country: United States $ 1,927 $ 2,264 $ 2,034 United Kingdom 313 382 472 Canada 167 135 165 Philippines and other 100 69 64 Total income before income tax (benefit) expense and equity (loss) income by country: $ 2,507 $ 2,850 $ 2,735 As of December 31, 2017 2016 2015 Property, plant and equipment, net by country: United States $ 53,579 $ 51,671 $ 49,680 United Kingdom 5,953 5,020 5,757 Canada 6,323 5,803 5,298 Philippines and other 16 15 34 Total property, plant and equipment, net by country $ 65,871 $ 62,509 $ 60,769 (1) The differences between the reportable segment amounts and the consolidated amounts, described as BHE and Other , relate to other corporate entities, including MidAmerican Energy Services, LLC, corporate functions and intersegment eliminations. (2) Income tax (benefit) expense includes the tax attributes of disregarded entities that are not required to pay income taxes and the earnings of which are taxable directly to BHE.
Schedule of Goodwill [Table Text Block]	The following table shows the change in the carrying amount of goodwill by reportable segment for the years ended December 31, 2017 and 2016 (in millions): BHE BHE MidAmerican NV Northern Pipeline BHE BHE Home- and PacifiCorp Funding Energy Powergrid Group Transmission Renewables Services Other Total December 31, 2015 $ 1,129 $ 2,102 $ 2,369 $ 1,056 $ 101 $ 1,428 $ 95 $ 794 $ 2 $ 9,076 Acquisitions — — — — — 4 — 46 — 50 Foreign currency translation — — — (126 ) — 42 — — (2 ) (86 ) Other — — — — (26 ) (4 ) — — — (30 ) December 31, 2016 1,129 2,102 2,369 930 75 1,470 95 840 — 9,010 Acquisitions — — — — — — — 508 — 508 Foreign currency translation — — — 61 — 101 — — — 162 Other — — — — (2 ) — — — — (2 ) December 31, 2017 $ 1,129 $ 2,102 $ 2,369 $ 991 $ 73 $ 1,571 $ 95 $ 1,348 $ — $ 9,678
MidAmerican Energy Company [Member]
Segment Reporting Information [Line Items]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	The following tables provide information on a reportable segment basis (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: Regulated electric $ 2,108 $ 1,985 $ 1,837 Regulated gas 719 637 661 Other 10 3 4 Total operating revenue $ 2,837 $ 2,625 $ 2,502 Depreciation and amortization: Regulated electric $ 458 $ 436 $ 366 Regulated gas 42 43 41 Total depreciation and amortization $ 500 $ 479 $ 407 Operating income: Regulated electric $ 485 $ 497 $ 385 Regulated gas 77 68 64 Other (1 ) — — Total operating income $ 561 $ 565 $ 449 Interest expense: Regulated electric $ 196 $ 178 $ 166 Regulated gas 18 18 17 Total interest expense $ 214 $ 196 $ 183 Income tax (benefit) expense from continuing operations: Regulated electric $ (212 ) $ (156 ) $ (163 ) Regulated gas 29 22 16 Other — 2 — Total income tax (benefit) expense from continuing operations $ (183 ) $ (132 ) $ (147 ) Net income: Regulated electric $ 570 $ 512 $ 413 Regulated gas 35 32 33 Other — (2 ) — Income from continuing operations 605 542 446 Income on discontinued operations — — 16 Net income $ 605 $ 542 $ 462 Years Ended December 31, 2017 2016 2015 Utility construction expenditures: Regulated electric $ 1,686 $ 1,564 $ 1,365 Regulated gas 87 72 81 Total utility construction expenditures $ 1,773 $ 1,636 $ 1,446 As of December 31, 2017 2016 2015 Total assets: Regulated electric $ 14,914 $ 14,113 $ 12,970 Regulated gas 1,403 1,345 1,251 Other 1 1 164 Total assets $ 16,318 $ 15,459 $ 14,385
MidAmerican Funding, LLC and Subsidiaries [Domain]
Segment Reporting Information [Line Items]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	The following tables provide information on a reportable segment basis (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: Regulated electric $ 2,108 $ 1,985 $ 1,837 Regulated gas 719 637 661 Other 19 9 17 Total operating revenue $ 2,846 $ 2,631 $ 2,515 Depreciation and amortization: Regulated electric $ 458 $ 436 $ 366 Regulated gas 42 43 41 Total depreciation and amortization $ 500 $ 479 $ 407 Operating income: Regulated electric $ 485 $ 497 $ 385 Regulated gas 77 68 64 Other — 1 2 Total operating income $ 562 $ 566 $ 451 Interest expense: Regulated electric $ 196 $ 178 $ 166 Regulated gas 18 18 17 Other 23 23 23 Total interest expense $ 237 $ 219 $ 206 Income tax (benefit) expense from continuing operations: Regulated electric $ (212 ) $ (156 ) $ (163 ) Regulated gas 29 22 16 Other (19 ) (5 ) (3 ) Total income tax (benefit) expense from continuing operations $ (202 ) $ (139 ) $ (150 ) Net income: Regulated electric $ 570 $ 512 $ 413 Regulated gas 35 32 33 Other (31 ) (12 ) (4 ) Income from continuing operations 574 532 442 Income on discontinued operations — — 16 Net income $ 574 $ 532 $ 458 Utility construction expenditures: Regulated electric $ 1,686 $ 1,564 $ 1,365 Regulated gas 87 72 81 Total utility construction expenditures $ 1,773 $ 1,636 $ 1,446 As of December 31, 2017 2016 2015 Total assets: Regulated electric $ 16,105 $ 15,304 $ 14,161 Regulated gas 1,482 1,424 1,330 Other 34 19 183 Total assets $ 17,621 $ 16,747 $ 15,674
Schedule of Goodwill [Table Text Block]	Goodwill by reportable segment as of December 31, 2017 and 2016 , was as follows (in millions): Regulated electric $ 1,191 Regulated gas 79 Total $ 1,270
Sierra Pacific Power Company [Member]
Segment Reporting Information [Line Items]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	The following tables provide information on a reportable segment basis for the years ended December 31 (in millions): Years Ended December 31, 2017 2016 2015 Operating revenue: Regulated electric $ 713 $ 702 $ 810 Regulated gas 99 110 137 Total operating revenue $ 812 $ 812 $ 947 Cost of sales: Regulated electric $ 268 $ 265 $ 374 Regulated gas 42 55 84 Total cost of sales $ 310 $ 320 $ 458 Gross margin: Regulated electric $ 445 $ 437 $ 436 Regulated gas 57 55 53 Total gross margin $ 502 $ 492 $ 489 Operating and maintenance: Regulated electric $ 148 $ 153 $ 149 Regulated gas 18 17 18 Total operating and maintenance $ 166 $ 170 $ 167 Depreciation and amortization: Regulated electric $ 100 $ 101 $ 96 Regulated gas 14 17 17 Total depreciation and amortization $ 114 $ 118 $ 113 Operating income: Regulated electric $ 176 $ 161 $ 168 Regulated gas 22 19 16 Total operating income $ 198 $ 180 $ 184 Interest expense: Regulated electric $ 39 $ 49 $ 56 Regulated gas 4 5 5 Total interest expense $ 43 $ 54 $ 61 Income tax expense: Regulated electric $ 48 $ 44 $ 43 Regulated gas 7 5 4 Total income tax expense $ 55 $ 49 $ 47 Years Ended December 31, 2017 2016 2015 Capital expenditures: Regulated electric $ 169 $ 176 $ 229 Regulated gas 17 18 23 Total capital expenditures $ 186 $ 194 $ 252 As of December 31, Total assets: 2017 2016 2015 Regulated electric $ 3,103 $ 3,119 $ 3,060 Regulated gas 300 314 316 Regulated common assets (1) 10 60 111 Total assets $ 3,413 $ 3,493 $ 3,487 (1) Consists principally of cash and cash equivalents not included in either the regulated electric or regulated natural gas segments.

Unaudited Quarterly Operating62

Unaudited Quarterly Operating Results Unaudited Quarterly Operating Results (Tables)	12 Months Ended
	Dec. 31, 2017
MidAmerican Energy Company [Member]
Quarterly Operating Results [Line Items]
Schedule of Quarterly Financial Information [Table Text Block]	2017 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 695 $ 658 $ 813 $ 671 Operating income 107 135 288 31 Net income (loss) 105 134 385 (19 ) 2016 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 625 $ 584 $ 795 $ 621 Operating income 100 139 284 42 Net income 76 131 320 15 Quarterly operating results are affected by, among other things, MidAmerican Energy's seasonal retail electricity prices, the timing of recognition of federal renewable electricity production tax credits related to MidAmerican Energy's wind-powered generating facilities and the seasonal impact of weather on electricity and natural gas sales.
MidAmerican Funding, LLC and Subsidiaries [Domain]
Quarterly Operating Results [Line Items]
Schedule of Quarterly Financial Information [Table Text Block]	2017 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 696 $ 659 $ 815 $ 676 Operating income 107 136 288 31 Net income (loss) 102 131 383 (42 ) 2016 1 st Quarter 2 nd Quarter 3 rd Quarter 4 th Quarter (In millions) Operating revenue $ 626 $ 585 $ 797 $ 623 Operating income 100 140 284 42 Net income 73 127 318 14 Quarterly operating results are affected by, among other things, MidAmerican Energy's seasonal retail electricity prices, the timing of recognition of federal renewable electricity production tax credits related to MidAmerican Energy's wind-powered generating facilities and the seasonal impact of weather on electricity and natural gas sales.
Nevada Power Company [Member]
Quarterly Operating Results [Line Items]
Schedule of Quarterly Financial Information [Table Text Block]	Three-Month Periods Ended March 31, June 30, September 30, December 31, 2017 2017 2017 2017 Operating revenues $ 392 $ 574 $ 819 $ 421 Operating income 52 157 317 37 Net income 10 77 176 (8 ) Three-Month Periods Ended March 31, June 30, September 30, December 31, 2016 2016 2016 2016 Operating revenues $ 399 $ 525 $ 766 $ 393 Operating income 46 141 324 69 Net income 3 66 188 22
Sierra Pacific Power Company [Member]
Quarterly Operating Results [Line Items]
Schedule of Quarterly Financial Information [Table Text Block]	Three-Month Periods Ended March 31, June 30, September 30, December 31, 2017 2017 2017 2017 Regulated electric operating revenue $ 159 $ 160 $ 215 $ 179 Regulated natural gas operating revenue 34 17 15 33 Operating income 46 36 75 41 Net income 24 17 44 24 Three-Month Periods Ended March 31, June 30, September 30, December 31, 2016 2016 2016 2016 Regulated electric operating revenue $ 170 $ 162 $ 207 $ 163 Regulated natural gas operating revenue 47 19 15 29 Operating income 41 28 69 42 Net income 17 10 38 19

Discontinued Operations Disco63

Discontinued Operations Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2017
MidAmerican Energy Company [Member] | Unregulated Retail Services [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Groups, Including Discontinued Operations [Table Text Block]	Significant line items constituting pre-tax income from discontinued operations and total cash flows from operating activities for the years ended December 31 are as follows (in millions): 2015 Operating revenue $ 905 Cost of sales $ 854 Cash flows from operating activities $ 30

Organization and Operations (De

Organization and Operations (Details)	12 Months Ended
	Dec. 31, 2017OperatingSegmentsOwnedAndOperatedCompanies
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Reportable Segments | OperatingSegments	8
Number of owned and operated utility companies in the United States	4
Number of states owned and operated utility companies serve customers	11
Number of owned and operated electricity distribution companies in Great Britain	2
Number of owned and operated interstate natural gas pipeline companies in the United States	2
Number of owned and operated electricity transmission companies in Canada	1
Number of owned and operated renewable energy businesses	1
Number of owned and operated residential real estate brokerage firms in the United States	1
Number of owned and operated real estate franchise networks in the United States	1

Summary of Significant Accoun65

Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts [Line Items]
Allowance for doubtful accounts	$ 40	$ 33

Summary of Significant Accoun66

Summary of Significant Accounting Policies - Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Summary of Significant Accounting Policies - Inventory [Abstract]
Energy Related Inventory, Other Fossil Fuel	$ 352	$ 402
Inventory, Raw Materials and Supplies, Gross	536	523
Replacement cost of inventory	$ 22	$ 27

Summary of Significant Accoun67

Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Significant Accounting Policies - Revenue Recognition [Abstract]
Unbilled revenue	$ 665	$ 643

Summary of Significant Accoun68

Summary of Significant Accounting Policies New Accounting Pronouncements (Details) - BHE - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 1,085
Tax Cuts and Jobs Act of 2017 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Federal statutory income tax rate	21.00%

Summary of SIgnificant Accoun69

Summary of SIgnificant Accounting Policies - PacifiCorp - Investments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
PacifiCorp [Member]
Unrealized gains and losses on available-for-sale securities	$ 0	$ 0

Summary of Significant Accoun70

Summary of Significant Accounting Policies - PacifiCorp - Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ 33
Ending balance	40	$ 33
PacifiCorp [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	7	7
Ending balance	10	7	$ 7
Allowance for Doubtful Accounts [Member] | PacifiCorp [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	7	7	7
Charged to operating costs and expenses, net	15	12	10
Write-offs, net	$ 12	12	10
Ending balance		$ 7	$ 7

Summary of Significant Accoun71

Summary of Significant Accounting Policies - PacifiCorp - Revenue Recognition (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Unbilled revenue	$ 665	$ 643
PacifiCorp [Member]
Unbilled revenue	$ 255	$ 275

Summary of Significant Accoun72

Summary of Significant Accounting Policies - PacifiCorp - Income Taxes (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Total regulatory assets		$ 2,950	$ 4,457
Regulatory Liabilities		7,511	3,120
Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets	[1]	143	1,754
Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities	[2]	$ 4,143	$ 25
PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Total regulatory assets		$ 1,061	$ 1,543
Regulatory Liabilities		3,071	1,032
Deferred investment tax credit		16	18
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets	[3]	0	421
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities		$ 1,960	$ 9
Tax Cuts and Jobs Act of 2017 [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities	[4]	$ 5,950
Tax Cuts and Jobs Act of 2017 [Member] | PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities		$ 2,358
[1]	Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[3]	(1)Amount primarily represents income tax benefits and expense related to certain property-related basis differences and other various items that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[4]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Summary of Significant Accoun73

Summary of Significant Accounting Policies - MEC - Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts Receivable, Current	$ 40	$ 33
MidAmerican Energy Company [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts Receivable, Current	$ 7	$ 7

Summary of Significant Accoun74

Summary of Significant Accounting Policies - MEC - Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Inventory [Line Items]
Inventory, Raw Materials and Supplies, Gross	$ 536	$ 523
Replacement cost of inventory	22	27
MidAmerican Energy Company [Member]
Inventory [Line Items]
Inventory, Raw Materials and Supplies, Gross	100	99
Public utility inventory, coal	117	137
Public utility inventory - natural gas in storage	24	24
Replacement cost of inventory	$ 22	$ 27

Summary of Significant Accoun75

Summary of Significant Accounting Policies - MEC - Revenue Recognition (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Unbilled revenue	$ 665	$ 643
MidAmerican Energy Company [Member]
Unbilled revenue	89	87
Adjustment clause accounts receivable (payable)	$ 72	$ 31

Summary of Significant Accoun76

Summary of Significant Accounting Policies Summary of Significant Accounting Policies - MEC - Income Taxes (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities, noncurrent		$ 7,309	$ 2,933
Regulatory assets		2,761	4,307
MidAmerican Energy Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities, noncurrent		1,661	883
Regulatory assets		204	1,161
Deferred Income Tax Charge [Member] | MidAmerican Energy Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory assets	[1]	0	985
Deferred Income Tax Charge [Member] | MidAmerican Energy Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities, noncurrent	[2]	$ 681	$ 0
[1]	(1)Amounts primarily represent income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[2]	(3)Amount predominantly represents the excess of nuclear decommission trust assets over the related asset retirement obligation. Refer to Note 12 for a discussion of asset retirement obligations.

Summary of Significant Accoun77

Summary of Significant Accounting Policies Summary of Significant Accounting Policies - MEC - New Accounting Pronouncements (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for Doubtful Accounts Receivable, Current	$ 40	$ 33
MidAmerican Energy Company [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for Doubtful Accounts Receivable, Current	7	7
Energy Related Inventory, Gas Stored Underground	$ 24	$ 24

Summary of Significant Accoun78

Summary of Significant Accounting Policies - MidAmerican Funding - Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
MidAmerican Funding, LLC and Subsidiaries [Domain]
Goodwill [Line Items]
Goodwill impairment	$ 0	$ 0	$ 0

Summary of Significant Accoun79

Summary of Significant Accounting Policies - NPC - Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts [Line Items]
Beginning balance	$ 33
Ending balance	40	$ 33
Nevada Power Company [Member] | Allowance for Doubtful Accounts [Member]
Allowance for Doubtful Accounts [Line Items]
Beginning balance	12	13	$ 14
Charged to operating costs and expenses, net	15	16	16
Write-offs, net	11	17	17
Ending balance	$ 16	$ 12	$ 13

Summary of Significant Accoun80

Summary of Significant Accounting Policies - NPC - Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Inventory [Line Items]
Inventory, Raw Materials and Supplies, Gross	$ 536	$ 523
Energy Related Inventory, Other Fossil Fuel	352	402
Nevada Power Company [Member]
Inventory [Line Items]
Inventory, Raw Materials and Supplies, Gross	56	60
Energy Related Inventory, Other Fossil Fuel	$ 3	$ 13

Summary of Significant Accoun81

Summary of Significant Accounting Policies Summary of Significant Accounting Policies - NPC - Property, Plant and Equipment, Net (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Nevada Power Company [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Allowance for Funds Used During Construction, Rate	8.09%	8.09%

Summary of Significant Accoun82

Summary of Significant Accounting Policies Summary of Significant Accounting Policies - NPC - Income Taxes (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Nevada Power Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Tax Cuts and Jobs Act of 2017 [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Nevada Power Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	21.00%

Summary of Significant Accoun83

Summary of Significant Accounting Policies - NPC - Revenue Recognition (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Unbilled Receivables, Current	$ 665	$ 643
Nevada Power Company [Member]
Unbilled Receivables, Current	$ 111	$ 91

Summary of Significant Accoun84

Summary of Significant Accounting Policies - SPPC - Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts [Line Items]
Beginning balance	$ 33
Ending balance	40	$ 33
Sierra Pacific Power Company [Member] | Allowance for Doubtful Accounts [Member]
Allowance for Doubtful Accounts [Line Items]
Beginning balance	2	1	$ 2
Charged to operating costs and expenses, net	2	2	1
Write-offs, net	2	1	2
Ending balance	$ 2	$ 2	$ 1

Summary of Significant Accoun85

Summary of Significant Accounting Policies - SPPC - Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Inventory [Line Items]
Inventory, Raw Materials and Supplies, Gross	$ 536	$ 523
Energy Related Inventory, Other Fossil Fuel	352	402
Sierra Pacific Power Company [Member]
Inventory [Line Items]
Inventory, Raw Materials and Supplies, Gross	42	36
Energy Related Inventory, Other Fossil Fuel	$ 7	$ 9

Summary of Significant Accoun86

Summary of Significant Accounting Policies - SPPC - Property, Plant and Equipment, Net (Details) - Sierra Pacific Power Company [Member]	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Electricity Generation Plant, Non-Nuclear [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Allowance for Funds Used During Construction, Rate	6.65%	7.62%
Natural Gas Processing Plant [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Allowance for Funds Used During Construction, Rate	5.63%	6.02%
Common Facilities [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Allowance for Funds Used During Construction, Rate	6.55%	7.44%

Summary of Significant Accoun87

Summary of Significant Accounting Policies - SPPC - Income Taxes (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Sierra Pacific Power Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Tax Cuts and Jobs Act of 2017 [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Sierra Pacific Power Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate	21.00%

Summary of Significant Accoun88

Summary of Significant Accounting Policies - SPPC - Revenue Recognition (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Unbilled revenue	$ 665	$ 643
Sierra Pacific Power Company [Member]
Unbilled revenue	$ 62	$ 52

Business Acquisitions (Details)

Business Acquisitions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Acquisition, net of cash acquired	$ (1,113)	$ (66)	$ (164)
Goodwill	9,678	9,010	9,076
Other acquisitions [Member]
Business Acquisition [Line Items]
Acquisition, net of cash acquired	1,100	66	164
Total assets assumed	1,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	487	54	84
Goodwill	$ 508	$ 50	$ 33

Property, Plant and Equipment90

Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 65,871	$ 62,509	$ 60,769
Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	81,836	78,478
Accumulated depreciation and amortization	(24,478)	(23,603)
Property, plant and equipment in service, net	57,358	54,875
Construction work-in-progress	2,200	1,800
Regulated Operation [Member] | Utility generation, distribution and transmission system [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 74,660	71,536
Regulated Operation [Member] | Utility generation, distribution and transmission system [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Regulated Operation [Member] | Utility generation, distribution and transmission system [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	80 years
Regulated Operation [Member] | Interstate natural gas pipeline assets [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 7,176	6,942
Regulated Operation [Member] | Interstate natural gas pipeline assets [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Regulated Operation [Member] | Interstate natural gas pipeline assets [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	80 years
Nonregulated Operation [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 7,499	6,596
Accumulated depreciation and amortization	(1,542)	(1,060)
Property, plant and equipment in service, net	5,957	5,536
Nonregulated Operation [Member] | Independent power plants [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	6,010	5,594
Nonregulated Operation [Member] | Other assets [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,489	1,002
Common Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment in service, net	63,315	60,411
Construction work-in-progress	2,556	2,098
Property, plant and equipment, net	$ 65,871	62,509
Nonregulated Operation [Member] | Independent power plants [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Nonregulated Operation [Member] | Independent power plants [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Nonregulated Operation [Member] | Other assets [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Nonregulated Operation [Member] | Other assets [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
PacifiCorp [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 19,203	19,162	19,039
MidAmerican Funding [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 14,221	$ 12,835	$ 11,737

Property, Plant and Equipment91

Property, Plant and Equipment, Net - PacifiCorp (Details) - PacifiCorp [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Electric Property Plant And Equipment In Service Gross		$ 27,880	$ 27,284
Public utility accumulated depreciation and amortization		(9,366)	(8,790)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress		18,525	18,505
Public Utilities, Property, Plant and Equipment, Construction Work in Progress		678	657
Public Utilities, Property, Plant and Equipment, Net		$ 19,203	$ 19,162
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service		2.90%	2.90%	2.90%
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments		$ 156
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation		$ 122	$ 117
Minimum [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life		14 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life		58 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life		20 years
Finite-Lived Intangible Asset, Useful Life	[1]	5 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life		5 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life		67 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life		75 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life		70 years
Finite-Lived Intangible Asset, Useful Life	[1]	62 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life		60 years
Electricity Generation Plant, Non-Nuclear [Member]
Property, Plant and Equipment [Line Items]
Electric Property Plant And Equipment In Service Gross		$ 12,490	12,371
Electric Transmission [Member]
Property, Plant and Equipment [Line Items]
Electric Property Plant And Equipment In Service Gross		6,226	6,055
Electric Distribution [Member]
Property, Plant and Equipment [Line Items]
Electric Property Plant And Equipment In Service Gross		6,792	6,590
Other Intangible Assets [Member]
Property, Plant and Equipment [Line Items]
Electric Property Plant And Equipment In Service Gross	[1]	937	884
Other Capitalized Property Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Electric Property Plant And Equipment In Service Gross		$ 1,435	1,384
Computer Software, Intangible Asset [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Asset, Useful Life		5 years
Computer Software, Intangible Asset [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Asset, Useful Life		10 years
Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress		$ 18,514	18,494
Nonregulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress		$ 11	$ 11
[1]	Computer software costs included in intangible plant are initially assigned a depreciable life of 5 to 10 years.

Property, Plant and Equipment92

Property, Plant and Equipment, Net Property, Plant and Equipment - MEC (Details) - MidAmerican Energy Company [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 13,410	$ 12,328
Public Utilities, Property, Plant and Equipment, Net	$ 14,207	$ 12,821
Regulated Electric [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service	2.60%	2.80%	3.00%
Natural Gas Processing Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service	2.70%	2.90%	2.90%
Regulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Plant in Service, Excluding Construction Work In Progress	$ 18,965	$ 17,770
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(5,561)	(5,448)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	13,404	12,322
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	797	493
Regulated Operation [Member] | Electric Operations [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation or Processing	12,107	11,282
Public Utilities, Property, Plant and Equipment, Transmission	1,838	1,726
Public Utilities, Property, Plant and Equipment, Distribution	3,380	3,197
Regulated Operation [Member] | Natural Gas Processing Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution	1,640	1,565
Nonregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(1)	(1)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	6	6
Gross public utility property, plant and equipment in service	$ 7	$ 7
Minimum [Member] | Regulated Operation [Member] | Electric Operations [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life	20 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life	52 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	20 years
Minimum [Member] | Regulated Operation [Member] | Natural Gas Processing Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	29 years
Minimum [Member] | Nonregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	25 years
Maximum [Member] | Regulated Operation [Member] | Electric Operations [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life	70 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life	75 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	75 years
Maximum [Member] | Regulated Operation [Member] | Natural Gas Processing Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	75 years
Maximum [Member] | Nonregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	50 years
Electricity Generation Plant, Non-Nuclear [Member] | Regulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Change in Accounting Estimates, Impact on Period of Change	$ 3
Change in Accounting Estimates, Impact on Future Periods	$ 34

Property, Plant and Equipment93

Property, Plant and Equipment, Net Property, Plant and Equipment - LLC (Details) - Other Capitalized Property Plant and Equipment [Member] - MidAmerican Funding, LLC and Subsidiaries [Domain] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 24
Accumulated depreciation and amortization	$ 10	$ 9
Construction in Progress, Gross		$ 1

Property, Plant and Equipment94

Property, Plant and Equipment, Net - NPC (Details) - Nevada Power Company [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Apr. 30, 2017
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 6,804	$ 6,883
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	73	114
Public Utilities, Property, Plant and Equipment, Net	$ 6,877	$ 6,997
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service	3.20%	3.20%	3.00%
Silverhawk Generating Station [Member]
Property, Plant and Equipment [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	25.00%
Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation or Processing	$ 3,707	$ 4,271
Public Utilities, Property, Plant and Equipment, Distribution	3,314	3,231
Public Utilities, Property, Plant and Equipment, Transmission	1,860	1,846
Public Utilities, Property, Plant and Equipment, Other Property, Plant and Equipment	793	738
Public Utilities, Property, Plant and Equipment, Plant in Service, Excluding Construction Work In Progress	9,674	10,086
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	2,871	3,205
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	6,803	6,881
Nonregulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 1	$ 2
130 Megawatts of Natural Gas Energy [Member]
Property, Plant and Equipment [Line Items]
Business Acquisition, Transaction Costs				$ 77
Minimum [Member] | Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life	30 years	30 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	20 years	20 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life	45 years	45 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	5 years	5 years
Minimum [Member] | Nonregulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	45 years	45 years
Maximum [Member] | Regulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life	55 years	55 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	65 years	65 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life	65 years	65 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	65 years	65 years
Maximum [Member] | Nonregulated Operation [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	45 years	45 years

Property, Plant and Equipment95

Property, Plant and Equipment, Net - SPPC (Details) - Sierra Pacific Power Company [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 2,760	$ 2,715
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	132	107
Public Utilities, Property, Plant and Equipment, Net	$ 2,892	$ 2,822
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service	3.00%	3.00%	2.90%
Electricity Generation Plant, Non-Nuclear [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation or Processing	$ 1,144	$ 1,137
Public Utilities, Property, Plant and Equipment, Distribution	1,459	1,417
Public Utilities, Property, Plant and Equipment, Transmission	786	771
Public Utilities, Property, Plant and Equipment, Other Property, Plant and Equipment	$ 181	$ 164
Electricity Generation Plant, Non-Nuclear [Member] | Minimum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life	25 years	25 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	20 years	20 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life	50 years	50 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	5 years	5 years
Electricity Generation Plant, Non-Nuclear [Member] | Maximum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Generation, Useful Life	60 years	60 years
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	100 years	100 years
Public Utilities, Property, Plant and Equipment, Transmission, Useful Life	100 years	100 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	70 years	70 years
Natural Gas Processing Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution	$ 390	$ 381
Public Utilities, Property, Plant and Equipment, Other Property, Plant and Equipment	$ 14	$ 15
Natural Gas Processing Plant [Member] | Minimum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	35 years	35 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	5 years	5 years
Natural Gas Processing Plant [Member] | Maximum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Distribution, Useful Life	70 years	70 years
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	70 years	70 years
Common Facilities [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Common	$ 294	$ 267
Public Utilities, Property, Plant and Equipment, Plant in Service, Excluding Construction Work In Progress	4,268	4,152
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(1,513)	(1,442)
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 2,755	$ 2,710
Common Facilities [Member] | Minimum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Common, Useful Life	5 years	5 years
Common Facilities [Member] | Maximum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Common, Useful Life	70 years	70 years
Nonregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Net, Excluding Construction Work In Progress	$ 5	$ 5
Nonregulated Operation [Member] | Minimum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	70 years	70 years
Nonregulated Operation [Member] | Maximum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life	70 years	70 years
Electricity Generation Plant, Non-Nuclear [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Change in Accounting Estimates, Impact on Future Periods	$ 9
Change in Accounting Estimate, Amount Deferred to Future Periods	$ 7

Jointly Owned Utility Facilit96

Jointly Owned Utility Facilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 9,651
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	4,353
Construction Work in Progress	183
PacifiCorp [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	4,425
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	1,872
Construction Work in Progress	$ 96
PacifiCorp [Member] | Jim Bridger Unit Nos 1 thru 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	67.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 1,442
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	616
Construction Work in Progress	$ 12
PacifiCorp [Member] | Hunter Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	94.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 474
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	172
Construction Work in Progress	$ 7
PacifiCorp [Member] | Hunter No. 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	60.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 297
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	106
Construction Work in Progress	$ 1
PacifiCorp [Member] | Wyodak [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	80.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 469
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	216
Construction Work in Progress	$ 1
PacifiCorp [Member] | Colstrip Unit Nos 3 and 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	10.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 247
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	131
Construction Work in Progress	$ 4
PacifiCorp [Member] | Hermiston [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 180
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	81
Construction Work in Progress	$ 1
PacifiCorp [Member] | Craig Units Nos 1 and 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	19.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 365
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	231
Construction Work in Progress	$ 3
PacifiCorp [Member] | Hayden Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	25.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 74
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	34
Construction Work in Progress	$ 0
PacifiCorp [Member] | Hayden No. 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	13.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 43
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	21
Construction Work in Progress	$ 0
PacifiCorp [Member] | Foote Creek [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	79.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 40
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	26
Construction Work in Progress	$ 0
PacifiCorp [Member] | Transmission and distribution facilities
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 794
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	238
Construction Work in Progress	67
MidAmerican Energy Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	4,126
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	1,882
Construction Work in Progress	$ 86
MidAmerican Energy Company [Member] | Transmission and distribution facilities
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 249
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	87
Construction Work in Progress	$ 1
MidAmerican Energy Company [Member] | Louisa Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	88.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 807
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	432
Construction Work in Progress	$ 8
MidAmerican Energy Company [Member] | Quad Cities Unit Nos 1 and 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	25.00%	[1]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 698	[1]
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	387	[1]
Construction Work in Progress	$ 20	[1]
MidAmerican Energy Company [Member] | Walter Scott, Jr. No. 3 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	79.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 617
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	316
Construction Work in Progress	$ 8
MidAmerican Energy Company [Member] | Walter Scott Jr Unit No 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	60.00%	[2]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 456	[2]
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	112	[2]
Construction Work in Progress	1	[2]
Revenue sharing credits netted against facility in service	319
Revenue sharing credits netted against accumulated depreciation	$ 81
MidAmerican Energy Company [Member] | George Neal No. 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	41.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 307
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	159
Construction Work in Progress	$ 1
MidAmerican Energy Company [Member] | Ottumwa Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	52.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 567
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	206
Construction Work in Progress	$ 40
MidAmerican Energy Company [Member] | George Neal Unit No 3 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	72.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 425
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	183
Construction Work in Progress	7
NV Energy [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	814
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	430
Construction Work in Progress	$ 1
NV Energy [Member] | Transmission and distribution facilities
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 206
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	45
Construction Work in Progress	$ 0
NV Energy [Member] | Navajo Generating Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	11.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 220
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	152
Construction Work in Progress	$ 0
NV Energy [Member] | Valmy [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 388
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	233
Construction Work in Progress	$ 1
BHE Pipeline Group [Member] | BHE Pipeline Group - common facilities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 286
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	169
Construction Work in Progress	$ 0
[1]	Includes amounts related to nuclear fuel.
[2]	Facility in-service and accumulated depreciation and amortization amounts are net of credits applied under Iowa revenue sharing arrangements totaling $319 million and $81 million, respectively.

Jointly Owned Utility Facilit97

Jointly Owned Utility Facilities - PacifiCorp (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 9,651
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	4,353
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	183
PacifiCorp [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	4,425
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	1,872
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 96
PacifiCorp [Member] | Jim Bridger Unit Nos 1 thru 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	67.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 1,442
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	616
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 12
PacifiCorp [Member] | Hunter Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	94.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 474
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	172
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 7
PacifiCorp [Member] | Hunter No. 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	60.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 297
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	106
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
PacifiCorp [Member] | Wyodak [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	80.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 469
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	216
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
PacifiCorp [Member] | Colstrip Unit Nos 3 and 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	10.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 247
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	131
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 4
PacifiCorp [Member] | Hermiston [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 180
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	81
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
PacifiCorp [Member] | Craig Units Nos 1 and 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	19.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 365
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	231
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 3
PacifiCorp [Member] | Hayden Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	25.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 74
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	34
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
PacifiCorp [Member] | Hayden No. 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	13.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 43
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	21
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
PacifiCorp [Member] | Foote Creek [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	79.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 40
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	26
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
PacifiCorp [Member] | Transmission and distribution facilities
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 794
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	238
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 67

Jointly Owned Utility Facilit98

Jointly Owned Utility Facilities Jointly Owned Utility Facilities - MEC (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 9,651
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	4,353
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	183
MidAmerican Energy Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	4,126
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	1,882
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 86
MidAmerican Energy Company [Member] | Louisa Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	88.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 807
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	432
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 8
MidAmerican Energy Company [Member] | Quad Cities Unit Nos 1 and 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	25.00%	[1]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 698	[1]
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	387	[1]
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 20	[1]
MidAmerican Energy Company [Member] | Walter Scott, Jr. No. 3 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	79.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 617
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	316
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 8
MidAmerican Energy Company [Member] | Walter Scott Jr Unit No 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	60.00%	[2]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 456	[2]
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	112	[2]
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	1	[2]
Revenue sharing credits netted against facility in service	319
Revenue sharing credits netted against accumulated depreciation	$ 81
MidAmerican Energy Company [Member] | George Neal No. 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	41.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 307
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	159
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
MidAmerican Energy Company [Member] | Ottumwa Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	52.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 567
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	206
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 40
MidAmerican Energy Company [Member] | George Neal Unit No 3 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	72.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 425
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	183
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 7
MidAmerican Energy Company [Member] | Transmission facilities
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 249
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	87
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
[1]	(1)Includes amounts related to nuclear fuel.
[2]	(2)Plant in service and accumulated depreciation and amortization amounts are net of credits applied under Iowa revenue sharing arrangements totaling $319 million and $81 million, respectively.

Jointly Owned Utility Facilit99

Jointly Owned Utility Facilities - NPC (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 9,651
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	4,353
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	183
Nevada Power Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	414
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	194
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
Nevada Power Company [Member] | Navajo Generating Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	11.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 220
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	152
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
Nevada Power Company [Member] | ON Line Transmission Line [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	24.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 146
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	16
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
Nevada Power Company [Member] | Other Transmission Facilities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 48
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	26
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0

Jointly Owned Utility Facili100

Jointly Owned Utility Facilities - SPPC (Details) $ in Millions	Dec. 31, 2017USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 9,651
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	4,353
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	183
Sierra Pacific Power Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	400
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	236
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
Sierra Pacific Power Company [Member] | Valmy [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 388
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	233
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
Sierra Pacific Power Company [Member] | ON Line Transmission Line [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	1.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 8
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	1
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
Sierra Pacific Power Company [Member] | Valmy Transmission Line [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 4
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	2
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0

Regulatory Matters - Regulatory

Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Regulatory assets		$ 189	$ 150
Regulatory assets, noncurrent		2,761	4,307
Total regulatory assets		2,950	4,457
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		1,100	2,800
Deferred Income Tax Charge [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[1]	$ 143	1,754
Regulatory asset amortization period years	[1]	Various
Employee benefit plans [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[2]	$ 675	816
Regulatory asset amortization period years	[2]	15.7540740740741
Asset disposition costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 387	281
Regulatory asset amortization period years		Various
Deferred net power costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 58	38
Regulatory asset amortization period years		2.27586206896552
Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 334	301
Regulatory asset amortization period years		13.1467065868263
Unrealized loss on regulated derivative contracts [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 122	154
Regulatory asset amortization period years		4
Abandoned Projects [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 156	159
Regulatory asset amortization period years		3.35897435897436
Deferred Operating Costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 147	97
Regulatory asset amortization period years		13
Unamortized contract values [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 89	98
Regulatory asset amortization period years		6
Regulatory assets other [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 839	$ 759
Regulatory asset amortization period years		Various
[1]	Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[2]	(1)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.

Regulatory Matters - Regulat102

Regulatory Matters - Regulatory Liabilities (Details) - USD ($) $ in Millions		1 Months Ended			12 Months Ended
		Jul. 31, 2016	Oct. 31, 2015	Nov. 30, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Liabilities [Line Items]
Federal statutory income tax rate					35.00%	35.00%	35.00%
Regulatory liabilities					$ 202	$ 187
Regulatory liabilities, noncurrent					7,309	2,933
Regulatory Liabilities					7,511	3,120
Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[1]				$ 4,143	25
Weighted average remaining life	[1]				Various
Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[2]				$ 2,349	2,242
Weighted average remaining life	[2]				26.845466155811
Deferred net power costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities					$ 8	64
Weighted average remaining life					2
Asset Retirement Obligation Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities					$ 177	122
Weighted average remaining life					34.638418079096
Levelized depreciation [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities					$ 332	244
Weighted average remaining life					22
Impact fees [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities					$ 89	90
Weighted average remaining life					6
Employee benefit plans [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[3]				$ 69	25
Weighted average remaining life	[3]				10.6086956521739
Unrealized gain on regulated derivative contracts [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities					$ 3	6
Weighted average remaining life					1
Regulatory liabilities other [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities					$ 341	$ 302
Weighted average remaining life					Various
Amount for discontinuance of CWIP in rate base [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount			$ 82
Amount for change to flow through method for income taxes [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount					$ 45
AltaLink [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 415
Public Utilities, Approved Rate Increase (Decrease), Amount					200
AltaLink [Member] | 2015-2016 GTA [Member] | GTA 2015 [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount		599
AltaLink [Member] | 2015-2016 GTA [Member] | GTA 2016 [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount		685
AltaLink [Member] | Amount previously collected as CWIP given as refund [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount		277			$ 200
AltaLink [Member] | Amount previously collected as CWIP given as returns [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount		12
AltaLink [Member] | Amount for change to flow through method for income taxes [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount		$ 68
2015-2016 GTA [Member] | AltaLink [Member] | GTA 2015 [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount			672	$ 811
2015-2016 GTA [Member] | AltaLink [Member] | GTA 2016 [Member] | Alberta Utilities Commission [Member]
Regulatory Liabilities [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount			$ 704	$ 1,000
Tax Cuts and Jobs Act of 2017 [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate					21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[4]				$ 5,950
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.
[3]	(3)Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized.
[4]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Regulatory Matters - PacifiCorp

Regulatory Matters - PacifiCorp - Regulatory Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Regulatory assets		$ 189	$ 150
Regulatory assets, noncurrent		2,761	4,307
Total regulatory assets		2,950	4,457
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		1,100	2,800
Deferred Income Tax Charge [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[1]	$ 143	1,754
Regulatory asset amortization period years	[1]	Various
Employee benefit plans [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[2]	$ 675	816
Regulatory asset amortization period years	[2]	15.7540740740741
Unamortized contract values [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 89	98
Regulatory asset amortization period years		6
Deferred net power costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 58	38
Regulatory asset amortization period years		2.27586206896552
Unrealized loss on regulated derivative contracts [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 122	154
Regulatory asset amortization period years		4
Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 334	301
Regulatory asset amortization period years		13.1467065868263
PacifiCorp [Member]
Regulatory Assets [Line Items]
Regulatory assets		$ 31	53
Regulatory assets, noncurrent		1,030	1,490
Total regulatory assets		1,061	1,543
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		589	1,019
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[3]	$ 0	421
Regulatory asset amortization period years	[3]	N/A
PacifiCorp [Member] | Employee benefit plans [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[4]	$ 418	525
Regulatory asset amortization period years	[4]	20 years
PacifiCorp [Member] | Utah mine disposition [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[5]	$ 156	166
Regulatory asset amortization period years	[5]	Various
PacifiCorp [Member] | Unamortized contract values [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 89	98
Regulatory asset amortization period years		6 years
PacifiCorp [Member] | Deferred net power costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 21	33
Regulatory asset amortization period years		1 year
PacifiCorp [Member] | Unrealized loss on regulated derivative contracts [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 101	73
Regulatory asset amortization period years		4 years
PacifiCorp [Member] | Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 100	82
Regulatory asset amortization period years		22 years
PacifiCorp [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 176	$ 145
Regulatory asset amortization period years		Various
[1]	Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[2]	(1)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.
[3]	(1)Amount primarily represents income tax benefits and expense related to certain property-related basis differences and other various items that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[4]	(2)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in rates when recognized.
[5]	(3)Amounts represent regulatory assets established as a result of the Utah mine disposition in 2015 for the net property, plant and equipment not considered probable of disallowance and for the portion of losses associated with the assets held for sale, UMWA 1974 Pension Plan withdrawal and closure costs incurred to date considered probable of recove

Regulatory Matters - PacifiC104

Regulatory Matters - PacifiCorp - Regulatory Liabilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Regulatory liabilities		$ 202	$ 187
Regulatory liabilities, noncurrent		7,309	2,933
Regulatory Liabilities		7,511	3,120
Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[1]	$ 2,349	2,242
Regulatory liability amortization period years	[1]	26.845466155811
Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[2]	$ 4,143	$ 25
Regulatory liability amortization period years	[2]	Various
PacifiCorp [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Regulatory liabilities		$ 75	$ 54
Regulatory liabilities, noncurrent		2,996	978
Regulatory Liabilities		3,071	1,032
PacifiCorp [Member] | Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities, noncurrent		955	917
Regulatory Liabilities	[3]	$ 955	917
Regulatory liability amortization period years	[3]	26 years
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities		$ 1,960	9
Regulatory liability amortization period years		Various
PacifiCorp [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities		$ 156	$ 106
Regulatory liability amortization period years		Various
Tax Cuts and Jobs Act of 2017 [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[4]	$ 5,950
Tax Cuts and Jobs Act of 2017 [Member] | PacifiCorp [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities		$ 2,358
[1]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[3]	(1)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying c
[4]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Regulatory Matters - MEC - Regu

Regulatory Matters - MEC - Regulatory Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Regulatory assets		$ 2,761	$ 4,307
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		$ 1,100	2,800
Deferred Income Tax Charge [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years	[1]	Various
Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		13.1467065868263
Employee benefit plans [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years	[2]	15.7540740740741
Unrealized loss on regulated derivative contracts [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		4
MidAmerican Energy Company [Member]
Regulatory Assets [Line Items]
Regulatory assets		$ 204	1,161
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		200	1,200
MidAmerican Energy Company [Member] | Deferred Income Tax Charge [Member]
Regulatory Assets [Line Items]
Regulatory assets	[3]	$ 0	985
MidAmerican Energy Company [Member] | Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period	[4]	10 years
Regulatory assets	[4]	$ 133	105
MidAmerican Energy Company [Member] | Employee benefit plans [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period	[5]	13 years
Regulatory assets	[5]	$ 38	40
MidAmerican Energy Company [Member] | Unrealized loss on regulated derivative contracts [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		1 year
Regulatory assets		$ 6	2
MidAmerican Energy Company [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		Various
Regulatory assets		$ 27	$ 29
[1]	Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[2]	(1)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.
[3]	(1)Amounts primarily represent income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.
[4]	(2)Amount predominantly relates to asset retirement obligations for fossil-fueled and wind-powered generating facilities. Refer to Note 12 for a discussion of asset retirement obligations.
[5]	(3)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.

Regulatory Matters - MEC - R106

Regulatory Matters - MEC - Regulatory Liabilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Regulatory Liabilities [Line Items]
Regulatory liabilities		$ 7,309	$ 2,933
Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[1]	26.845466155811
Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[2]	Various
Asset Retirement Obligation Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		34.638418079096
Pension and other postretirement costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[3]	10.6086956521739
Unrealized gain on regulated derivative contracts [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		1
MidAmerican Energy Company [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities		$ 1,661	883
MidAmerican Energy Company [Member] | Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[4]	28 years
Regulatory liabilities	[4]	$ 688	665
MidAmerican Energy Company [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[5]	28 years
Regulatory liabilities	[5]	$ 681	0
MidAmerican Energy Company [Member] | Asset Retirement Obligation Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[5]	35 years
Regulatory liabilities	[5]	$ 173	117
MidAmerican Energy Company [Member] | Transmission MVP CWIP Return [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[6]	55 years
Regulatory liabilities	[6]	$ 35	35
MidAmerican Energy Company [Member] | Regulatory revenue sharing arrangement [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[7]	1 year
Regulatory liabilities	[7]	$ 26	30
MidAmerican Energy Company [Member] | Pension and other postretirement costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[8]	11 years
Regulatory liabilities	[8]	$ 41	12
MidAmerican Energy Company [Member] | Unrealized gain on regulated derivative contracts [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		1 year
Regulatory liabilities		$ 3	6
MidAmerican Energy Company [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		Various
Regulatory liabilities		$ 14	$ 18
[1]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[3]	(3)Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized.
[4]	(1)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing utility plant in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.
[5]	(3)Amount predominantly represents the excess of nuclear decommission trust assets over the related asset retirement obligation. Refer to Note 12 for a discussion of asset retirement obligations.
[6]	(4)Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized.
[7]	(5)Represents AFUDC accrued on transmission MVPs that is deducted from rate base as a result of the inclusion of related construction work-in-progress in rate base.
[8]	(6)Represents current-year accruals under a regulatory arrangement in Iowa in which equity returns exceeding specified thresholds reduce utility plant upon final determination.

Regulatory Matters Regulatory M

Regulatory Matters Regulatory Matters - NPC - Regulatory Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Total regulatory assets		$ 2,950	$ 4,457
Regulatory assets		189	150
Regulatory assets		2,761	4,307
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		$ 1,100	2,800
Deferred Operating Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		13
Total regulatory assets		$ 147	97
Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		13.1467065868263
Total regulatory assets		$ 334	301
Abandoned Projects [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		3.35897435897436
Total regulatory assets		$ 156	159
Regulatory assets other [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		Various
Total regulatory assets		$ 839	759
Nevada Power Company [Member]
Regulatory Assets [Line Items]
Total regulatory assets		969	1,020
Regulatory assets		28	20
Regulatory assets		941	1,000
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		$ 363	560
Nevada Power Company [Member] | Decommissioning costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P6Y
Total regulatory assets		$ 231	114
Nevada Power Company [Member] | Deferred Operating Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P12Y
Total regulatory assets		$ 169	127
Nevada Power Company [Member] | Acquisition-related Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P27Y
Total regulatory assets		$ 130	136
Nevada Power Company [Member] | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years	[1]	P8Y
Total regulatory assets	[1]	$ 89	105
Nevada Power Company [Member] | Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P7Y
Total regulatory assets		$ 72	74
Nevada Power Company [Member] | Abandoned Projects [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P3Y
Total regulatory assets		$ 58	75
Nevada Power Company [Member] | Legacy Meters [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P15Y
Total regulatory assets		$ 56	60
Nevada Power Company [Member] | ON Line Transmission Line [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P36Y
Total regulatory assets		$ 47	44
Nevada Power Company [Member] | Deferred Excess Energy Costs [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		P2Y
Total regulatory assets		$ 46	46
Nevada Power Company [Member] | Deferred Income Taxes [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[2]	$ 0	141
Nevada Power Company [Member] | Regulatory assets other [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		Various
Nevada Power Company [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 71	$ 98
[1]	(1)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.
[2]	Amounts primarily represent income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

Regulatory Matters - NPC - Regu

Regulatory Matters - NPC - Regulatory Liabilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Liabilities [Line Items]
Regulatory Liabilities		$ 7,511	$ 3,120
Regulatory liabilities		202	187
Regulatory liabilities		$ 7,309	$ 2,933
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[1]	Various
Regulatory Liabilities	[1]	$ 4,143	$ 25
Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[2]	26.845466155811
Regulatory Liabilities	[2]	$ 2,349	2,242
Impact fees [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		6
Regulatory Liabilities		$ 89	90
Regulatory liabilities other [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		Various
Regulatory Liabilities		$ 341	302
Nevada Power Company [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities		1,121	453
Regulatory liabilities		91	37
Regulatory liabilities		$ 1,030	$ 416
Federal statutory income tax rate		35.00%	35.00%	35.00%
Nevada Power Company [Member] | Deferred Income Taxes [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[3]	P33Y
Nevada Power Company [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[3]	$ 670	$ 9
Nevada Power Company [Member] | Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years	[4]	P31Y
Regulatory Liabilities	[4]	$ 307	294
Nevada Power Company [Member] | Impact fees [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		P6Y
Regulatory Liabilities		$ 89	90
Nevada Power Company [Member] | Energy Efficiency Program [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		P1Y
Regulatory Liabilities		$ 27	37
Nevada Power Company [Member] | Regulatory liabilities other [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		Various
Regulatory Liabilities		$ 28	$ 23
Tax Cuts and Jobs Act of 2017 [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[3]	$ 5,950
Tax Cuts and Jobs Act of 2017 [Member] | Nevada Power Company [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Nevada Power Company [Member] | Deferred Income Tax Charge [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[3]	$ 792
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.
[3]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.
[4]	(2)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

Regulatory Matters - NPC - Othe

Regulatory Matters - NPC - Other (Details)	1 Months Ended		12 Months Ended
	May 31, 2017USD ($)	Mar. 31, 2017USD ($)MW	Dec. 31, 2017USD ($)number	Dec. 31, 2016USD ($)
Public Utilities, General Disclosures [Line Items]
Regulatory assets			$ 2,761,000,000	$ 4,307,000,000
Nevada Power Company [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets			941,000,000	1,000,000,000
Nevada Power Company [Member] | Public Utilities Commission, Nevada [Member]
Public Utilities, General Disclosures [Line Items]
Customer Refund Liability, Current			$ 16,000,000
Impact Fee Payment Term | number			6
Nevada Power Company [Member] | General Rate Case [Member] | Public Utilities Commission, Nevada [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount			$ 29,000,000
Public Utilities, Filed Rate Increase (Decrease), Percent			2.00%
Public Utilities, Requested Rate Increase (Decrease), Amount			$ 0
Public Utilities, Approved Rate Increase (Decrease), Amount			$ 26,000,000
Public Utilities, Revenue Sharing, Percent			50.00%
Public Utilities, Return on Equity, Percentage			10.00%
Expense Related to Regulatory Rate Review			$ 28,000,000
Nevada Power Company [Member] | Energy Efficiency Rate Case [Member] | Public Utilities Commission, Nevada [Member]
Public Utilities, General Disclosures [Line Items]
Customer Refund Liability, Current			$ 10,000,000
257 Megawatts of Coal Energy [Member] | Nevada Power Company [Member]
Public Utilities, General Disclosures [Line Items]
Coal-Fired Power Plant Capacity | MW		257
Regulatory assets		$ 151,000,000
MGM Resorts International [Member] | Nevada Power Company [Member] | Public Utilities Commission, Nevada [Member]
Public Utilities, General Disclosures [Line Items]
Total impact fee				82,000,000
Wynn Las Vegas, LLC [Member] | Nevada Power Company [Member] | Public Utilities Commission, Nevada [Member]
Public Utilities, General Disclosures [Line Items]
Total impact fee				$ 15,000,000
Switch, Ltd. [Member] | Nevada Power Company [Member] | Public Utilities Commission, Nevada [Member]
Public Utilities, General Disclosures [Line Items]
Total impact fee	$ 27,000,000

Regulatory Matters - SPPC - Reg

Regulatory Matters - SPPC - Regulatory Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Total regulatory assets		$ 2,950	$ 4,457
Regulatory assets		189	150
Regulatory assets		2,761	4,307
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		1,100	2,800
Abandoned Projects [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 156	159
Regulatory asset amortization period years		3.35897435897436
Regulatory assets other [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 839	759
Regulatory asset amortization period years		Various
Sierra Pacific Power Company [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 332	435
Regulatory assets		32	25
Regulatory assets		300	410
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		$ 188	305
Sierra Pacific Power Company [Member] | Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period	[1]	8 years
Total regulatory assets	[1]	$ 110	128
Sierra Pacific Power Company [Member] | Acquisition-related Costs [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		29 years
Total regulatory assets		$ 77	80
Sierra Pacific Power Company [Member] | Abandoned Projects [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		7 years
Total regulatory assets		$ 34	39
Sierra Pacific Power Company [Member] | Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		2 years
Total regulatory assets		$ 23	25
Sierra Pacific Power Company [Member] | Loss on Reacquired Debt [Member]
Regulatory Assets [Line Items]
Regulatory Asset, Amortization Period		16 years
Total regulatory assets		$ 21	22
Sierra Pacific Power Company [Member] | Deferred Income Taxes [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 0	85
Sierra Pacific Power Company [Member] | Regulatory assets other [Member]
Regulatory Assets [Line Items]
Regulatory asset amortization period years		Various
Sierra Pacific Power Company [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 67	$ 56
[1]	Amounts represent income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

Regulatory Matters - SPPC - 111

Regulatory Matters - SPPC - Regulatory Liabilities - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Regulatory Liabilities		$ 7,511	$ 3,120
Regulatory liabilities		202	187
Regulatory liabilities		7,309	2,933
Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	[1]	$ 2,349	2,242
Regulatory liability amortization period years	[1]	26.845466155811
Regulatory liabilities other [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities		$ 341	$ 302
Regulatory liability amortization period years		Various
Sierra Pacific Power Company [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Regulatory Liabilities		$ 500	$ 290
Regulatory liabilities		19	69
Regulatory liabilities		$ 481	221
Sierra Pacific Power Company [Member] | Deferred Income Taxes [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		29 years
Regulatory Liabilities		$ 264	6
Sierra Pacific Power Company [Member] | Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		41 years
Regulatory Liabilities		$ 211	205
Sierra Pacific Power Company [Member] | Deferred Excess Energy Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory liability amortization period years		2 years
Regulatory Liabilities		$ 8	64
Sierra Pacific Power Company [Member] | Regulatory liabilities other [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities		$ 17	$ 15
Tax Cuts and Jobs Act of 2017 [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Sierra Pacific Power Company [Member]
Regulatory Liabilities [Line Items]
Federal statutory income tax rate		21.00%
[1]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

Regulatory Matters - SPPC - Oth

Regulatory Matters - SPPC - Other (Details) - Sierra Pacific Power Company [Member] - Public Utilities Commission, Nevada [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)number	Dec. 31, 2016USD ($)
Public Utilities, General Disclosures [Line Items]
Impact Fee Payment Term | number	3
Energy Efficiency Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Customer Refund Liability, Current	$ 1	$ 2
Electric Distribution [Member] | General Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	3
Gas Distribution [Member] | General Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	$ 2

Investments and Restricted C113

Investments and Restricted Cash and Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments [Abstract]
Investments	$ 2,526	$ 1,694
Equity Method Investments [Abstract]
Tax Equity Contributions	403	584	$ 170
Equity method investments	1,834	1,720
Restricted Cash and Investments [Abstract]
Restricted cash and investments	863	742
Investments, including equity method and restricted cash and investments, current	351	211
Investments, including equity method and restricted cash and investments, noncurrent	4,872	3,945
Investments, including equity method and restricted cash and investments	5,223	4,156
Quad Cities Station nuclear decommissioning trust funds [Member]
Restricted Cash and Investments [Abstract]
Decommissioning Fund Investments, Fair Value	515	460
Restricted Cash and Investments, Other [Member]
Restricted Cash and Investments [Abstract]
Restricted cash and investments	348	282
Electric Transmission Texas, LLC [Member]
Equity Method Investments [Abstract]
Equity method investments	$ 524	672
Equity method investment, ownership percentage	50.00%
Bridger Coal Company [Member]
Equity Method Investments [Abstract]
Equity method investments	$ 137	165
Equity method investment, ownership percentage	66.67%
Tax Equity Investments
Equity Method Investments [Abstract]
Equity method investments	$ 1,025	741
Other equity method investments [Member]
Equity Method Investments [Abstract]
Equity method investments	148	142
BYD Company Limited common stock [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) before Taxes	1,729	953
Investments [Abstract]
Available-for-sale Securities, Equity Securities	1,961	1,185
Rabbi trusts [Member]
Investments [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	441	403
Other investments [Member]
Investments [Abstract]
Other Investments	$ 124	$ 106

Investments and Restricted C114

Investments and Restricted Cash and Investments Investments and Restricted Cash and Investments - MEC - (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Investments and restricted cash and investments	$ 4,872	$ 3,945
MidAmerican Energy Company [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Decommissioning Fund Investments, Fair Value	515	460
Life Insurance, Corporate or Bank Owned, Amount	198	184
Other Investments	15	9
Investments and restricted cash and investments	$ 728	$ 653
MidAmerican Energy Company [Member] | Domestic Equity Securities [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Nuclear Decommissioning Trust Fund Ownership Percentage	56.00%	54.00%
MidAmerican Energy Company [Member] | US Government Corporations and Agencies Securities [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Nuclear Decommissioning Trust Fund Ownership Percentage	34.00%	35.00%
MidAmerican Energy Company [Member] | Domestic Corporate Debt Securities [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Nuclear Decommissioning Trust Fund Ownership Percentage	7.00%	8.00%
MidAmerican Energy Company [Member] | Other Securities [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Nuclear Decommissioning Trust Fund Ownership Percentage	3.00%	3.00%

Investments and Restricted C115

Investments and Restricted Cash and Investments - MidAmerican Funding - (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
MidAmerican Funding, LLC and Subsidiaries [Domain]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Life Insurance, Corporate or Bank Owned, Amount	$ 2	$ 2

Short-Term Debt and Credit F116

Short-Term Debt and Credit Facilities Short-Term Debt and Credit Facilities - Credit Facilities (Details) $ in Millions		Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051		$ 6,345
Short-term debt	[1]	4,488		1,869
Line of Credit Facility, Amounts Supported	[1]	594		457
Line of Credit Facility, Remaining Borrowing Capacity	[1]	3,969		4,019
Berkshire Hathaway Energy [Member]
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount		96		123
Line of Credit Facility, Maximum Borrowing Capacity		3,600	[2]	2,000
Short-term debt		3,331		834
Line of Credit Facility, Amounts Supported		7		7
Line of Credit Facility, Remaining Borrowing Capacity		262		1,159
PacifiCorp [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,000	[2]	1,000
Short-term debt		80		270
Line of Credit Facility, Amounts Supported		130		142
Line of Credit Facility, Remaining Borrowing Capacity		790		588
MidAmerican Funding [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		909	[2]	609
Short-term debt		0		99
Line of Credit Facility, Amounts Supported		370		220
Line of Credit Facility, Remaining Borrowing Capacity		539		290
NV Energy [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		650	[2]	650
Short-term debt		0		0
Line of Credit Facility, Amounts Supported		80		80
Line of Credit Facility, Remaining Borrowing Capacity		570		570
Northern Powergrid Holdings [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		203	[2]	185
Short-term debt		0		0
Line of Credit Facility, Amounts Supported		0		0
Line of Credit Facility, Remaining Borrowing Capacity		203		185
AltaLink [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,054	[2]	986
Short-term debt		345		289
Line of Credit Facility, Amounts Supported		7		8
Line of Credit Facility, Remaining Borrowing Capacity		702		689
Other [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,635	[2]	915
Short-term debt		732		377
Line of Credit Facility, Amounts Supported		0		0
Line of Credit Facility, Remaining Borrowing Capacity		903		538
Tax exempt bond obligations and commodity contract collateral requirement [Member] | PacifiCorp [Member]
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount		230		269
Line of Credit Facility, Amounts Supported		216		255
Certain transactions required by third parties [Member] | PacifiCorp [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amounts Supported		$ 14
Line of Credit [Member] | AltaLink Investments, L.P. [Member]
Line of Credit Facility [Line Items]
Debt to capitalization ratio		0.8
EBITDA to interest expense ratio		2.25
Short-term debt		$ 224		$ 263
Line of Credit [Member] | Berkshire Hathaway Energy [Member]
Line of Credit Facility [Line Items]
Debt to capitalization ratio		0.70
Line of Credit [Member] | PacifiCorp [Member]
Line of Credit Facility [Line Items]
Debt to capitalization ratio		0.65
Line of Credit [Member] | MidAmerican Funding [Member]
Line of Credit Facility [Line Items]
Debt to capitalization ratio		0.65
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.
[2]	(2)Includes amounts borrowed on a short-term loan totaling $600 million at BHE that was repaid in full in January 2018.

Short-Term Debt and Credit F117

Short-Term Debt and Credit Faciliites (Details) £ in Millions, CAD in Millions, $ in Millions		Dec. 31, 2017USD ($)		Dec. 31, 2017CAD	Dec. 31, 2017GBP (£)	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051				$ 6,345
Line of Credit Facility, Amounts Supported	[1]	(594)				(457)
Short-term Debt	[1]	(4,488)				(1,869)
Berkshire Hathaway Energy [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		3,600	[2]			2,000
Letters of Credit Outstanding, Amount		96				123
Line of Credit Facility, Amounts Supported		(7)				(7)
Short-term Debt		$ (3,331)				$ (834)
Berkshire Hathaway Energy [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		1.74%		1.74%	1.74%	0.88%
Debt to capitalization ratio		0.70		0.70	0.70
Berkshire Hathaway Energy [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amounts Supported		$ (7)				$ (7)
PacifiCorp [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,000	[2]			1,000
Line of Credit Facility, Amounts Supported		(130)				(142)
Short-term Debt		$ (80)				$ (270)
PacifiCorp [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		1.83%		1.83%	1.83%	0.96%
Debt to capitalization ratio		0.65		0.65	0.65
MidAmerican Funding [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 909	[2]			$ 609
Line of Credit Facility, Amounts Supported		(370)				(220)
Short-term Debt		$ 0				(99)
MidAmerican Funding [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		0.73%		0.73%	0.73%
Debt to capitalization ratio		0.65		0.65	0.65
Sierra Pacific Power Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 250				250
Line of Credit Facility, Amounts Supported		(80)				(80)
Northern Powergrid Holdings [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		203	[2]			185
Line of Credit Facility, Amounts Supported		0				0
Short-term Debt		$ 0				$ 0
AltaLink, L.P. [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		1.42%		1.42%	1.42%	0.99%
Debt to capitalization ratio		0.75		0.75	0.75
Short-term Debt		$ (121)				$ (26)
ALP Investments [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		2.40%		2.40%	2.40%	1.74%
Debt to capitalization ratio		0.8		0.8	0.8
Short-term Debt		$ (224)				$ (263)
EBITDA to interest expense ratio		2.25		2.25	2.25
ALP Investments [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | CAD				CAD 10
HomeServices [Member]
Line of Credit Facility [Line Items]
Short-term Debt		$ (292)				(50)
BHE Renewables [Member]
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount		118				$ 106
Unsecured credit facility, $600 million, expiring June 2020 [Member] | PacifiCorp [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		600
Unsecured credit facility, $600 million, expiring June 2020 [Member] | MidAmerican Funding [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		900
Unsecured credit facility, $400 million, expiring June 2020 [Member] | PacifiCorp [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		400
Unsecured credit facility, $2 billion, expiring June 2020 [Member] | Berkshire Hathaway Energy [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 2,000
Unsecured credit facility, £150 million, expiring August 2020 [Member] | Northern Powergrid Holdings [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | £					£ 150
Debt to regulated asset value		0.8		0.8	0.8
Interest coverage ratio		2.5		2.5	2.5
Unsecured credit facility, £150 million, expiring August 2020 [Member] | Northern Powergrid (Northeast) Limited [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt to regulated asset value		0.65		0.65	0.65
Unsecured credit facility, £150 million, expiring August 2020 [Member] | Northern Powergrid (Yorkshire) plc [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt to regulated asset value		0.65		0.65	0.65
Unsecured credit facility, $600 million, expiring September 2022 [Member] | HomeServices [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 600
Debt, Weighted Average Interest Rate		2.75%		2.75%	2.75%	1.77%
Unsecured credit facility, $1 billion, expiring January 2018 to December 2018 [Member] | HomeServices [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 1,035
Debt, Weighted Average Interest Rate		3.60%		3.60%	3.60%
Short-term Debt		$ (440)
Unsecured credit facility, $565 million, expiring January 2018 to December 2018 [Member] | HomeServices [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						$ 565
Debt, Weighted Average Interest Rate						2.77%
Short-term Debt						$ (327)
Letter of credit and reimbursement facility, Topaz and Solar Star [Member] | BHE Renewables [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		435				627
Letters of Credit Outstanding, Amount		357				$ 599
Unsecured credit facility, $1 billion, expiring May 2018 [Member] | Berkshire Hathaway Energy [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,000
Secured credit facility, C$750 million, expiring December 2019 [Member] | AltaLink, L.P. [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | CAD				CAD 750
Secured credit facility, C$75 million, expiring December 2019 [Member] | AltaLink, L.P. [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | CAD				75
Unsecured credit facility, C$300 million, expiring December 2022 [Member] | ALP Investments [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | CAD				300
Unsecured credit facility, C$200 million, expiring December 2018 [Member] | ALP Investments [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity | CAD				CAD 200
Line of Credit [Member] | Sierra Pacific Power Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 250
Debt to capitalization ratio		0.65		0.65	0.65
Line of Credit [Member] | Secured credit facility, $250 million, expiring June 2020 [Domain] | Sierra Pacific Power Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 250
Debt to capitalization ratio		0.65		0.65	0.65
Line of Credit [Member] | Senior unsecured credit facility, $400 million, expiring June 2020 [Member] | Nevada Power Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 400
Debt to capitalization ratio		0.65		0.65	0.65
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.
[2]	(2)Includes amounts borrowed on a short-term loan totaling $600 million at BHE that was repaid in full in January 2018.

Short-Term Debt and Credit F118

Short-Term Debt and Credit Facilities Short-Term Debt (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Short-term debt	[1]	$ 4,488	$ 1,869
Short-term Debt [Member] | Variable-rate Term Loan, 2.27%, expiring June 2018 [Member]
Short-term Debt [Line Items]
Short-term debt		$ 600
Debt, Weighted Average Interest Rate		2.27%
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.

Short-Term Debt and Credit F119

Short-Term Debt and Credit Facilities - PacifiCorp - Credit Facility (Details) $ in Millions		Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051		$ 6,345
Short-term Debt	[1]	(4,488)		(1,869)
Line of Credit Facility, Amounts Supported	[1]	(594)		(457)
Line of Credit Facility, Remaining Borrowing Capacity	[1]	3,969		4,019
PacifiCorp [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,000	[2]	1,000
Short-term Debt		(80)		(270)
Line of Credit Facility, Amounts Supported		(130)		(142)
Line of Credit Facility, Remaining Borrowing Capacity		$ 790		$ 588
PacifiCorp [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		1.83%		0.96%
Debt to capitalization ratio		0.65
PacifiCorp [Member] | Commercial Paper [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		1.83%		0.96%
PacifiCorp [Member] | Unsecured credit facility, $600 million, expiring June 2017 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 600
PacifiCorp [Member] | Unsecured credit facility, $600 million, expiring March 2018 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		400
PacifiCorp [Member] | Certain transactions required by third parties [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amounts Supported		(14)
PacifiCorp [Member] | Tax exempt bond obligations and commodity contract collateral requirement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amounts Supported		(216)		$ (255)
Letters of Credit Outstanding, Amount		$ 230		$ 269
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.
[2]	(2)Includes amounts borrowed on a short-term loan totaling $600 million at BHE that was repaid in full in January 2018.

Short-Term Debt and Credit F120

Short-Term Debt and Credit Facilities - MEC - Credit Facility (Details) $ in Millions		Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051	$ 6,345
Short-term Debt	[1]	(4,488)	(1,869)
Line of Credit Facility, Amounts Supported	[1]	(594)	(457)
Line of Credit Facility, Remaining Borrowing Capacity	[1]	3,969	4,019
MidAmerican Energy Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		905	605
Short-term Debt		0	(99)
Line of Credit Facility, Amounts Supported		(370)	(220)
Line of Credit Facility, Remaining Borrowing Capacity		$ 535	$ 286
MidAmerican Energy Company [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt to capitalization ratio		0.65
MidAmerican Energy Company [Member] | Commercial Paper [Member]
Line of Credit Facility [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time			0.73%
Regulatory Approval for Additional Short-Term Debt Issuances		$ 905
MidAmerican Energy Company [Member] | Unsecured credit facility, $900 million, expiring March 2020 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		900
MidAmerican Energy Company [Member] | Unsecured 364-day Credit Facility, $5 million, expiring June [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 5
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.

Short-Term Debt and Credit F121

Short-Term Debt and Credit Facilities - MidAmerican Funding (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051	$ 6,345
MidAmerican Funding, LLC and Subsidiaries [Domain] | Unsecured 364-day credit facility, $4 million, expiring June [Member] | MHC, Inc. [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		4
Outstanding balance on credit facility		$ 0	$ 0
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.

Short-Term Debt and Credit F122

Short-Term Debt and Credit Facilities - NPC - Credit Facility (Details)		Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051,000,000	$ 6,345,000,000
Nevada Power Company [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit		0	$ 0
Nevada Power Company [Member] | Senior unsecured credit facility, $400 million, expiring June 2020 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 400,000,000
Debt to capitalization ratio		0.65
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.

Short-Term Debt and Credit F123

Short-Term Debt and Credit Facilities - SPPC - Credit Facility (Details)		Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051,000,000	$ 6,345,000,000
Line of Credit Facility, Amounts Supported	[1]	(594,000,000)	(457,000,000)
Line of Credit Facility, Remaining Borrowing Capacity	[1]	3,969,000,000	4,019,000,000
Sierra Pacific Power Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		250,000,000	250,000,000
Line of Credit Facility, Amounts Supported		(80,000,000)	(80,000,000)
Line of Credit Facility, Remaining Borrowing Capacity		170,000,000	170,000,000
Sierra Pacific Power Company [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		250,000,000
Long-term Line of Credit		$ 0	$ 0
Debt to capitalization ratio		0.65
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.

BHE Debt (Details)

BHE Debt (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 31, 2018	Sep. 30, 2017
BHE Debt [Line Items]
Par value		$ 35,376
Noncurrent senior debt		5,452	$ 7,418
BHE junior subordinated debentures		100	944
Interest expense to Berkshire Hathaway		16	65	$ 104
PacifiCorp [Member] | First Mortgage Bonds, 4.10% To 6.35%, Due 2038 To 2042 [Member]
BHE Debt [Line Items]
Par value		1,250
PacifiCorp [Member] | First Mortgage Bonds, 5.25% To 6.25%, Due 2034 to 2037 [Member]
BHE Debt [Line Items]
Par value		2,050
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member]
BHE Debt [Line Items]
Par value		1,875
PacifiCorp [Member] | Tax-exempt bond obligations, variable rate series, due 2018 to 2020 [Member]
BHE Debt [Line Items]
Par value		79
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member]
BHE Debt [Line Items]
Par value		1,224
BHE [Member] | BHE Junior Subordinated Debentures, due 2044 [Member]
BHE Debt [Line Items]
Debt Instrument, Repurchased Face Amount						$ 944
BHE [Member] | BHE Junior Subordinated Debentures, due June 2057 [Member]
BHE Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.00%
Conversion of Stock, Shares Converted	181,819
Senior Notes [Member] | Berkshire Hathaway Energy [Member]
BHE Debt [Line Items]
Par value		6,496
Total BHE Senior Debt		6,452	7,818
Current senior debt		1,000	400
Noncurrent senior debt		5,452	7,418
Gain (Loss) on Extinguishment of Debt		410
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 1.10%, Senior Notes, due 2017 [Member]
BHE Debt [Line Items]
Par value		0
Total BHE Senior Debt		$ 0	$ 400
Debt Instrument, Interest Rate, Stated Percentage		1.10%	1.10%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 5.75%, Senior Notes, due 2018 [Member]
BHE Debt [Line Items]
Par value		$ 650
Total BHE Senior Debt		$ 650	$ 649
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 2.00%, Senior Notes, due 2018 [Member]
BHE Debt [Line Items]
Par value		$ 350
Total BHE Senior Debt		$ 350	$ 349
Debt Instrument, Interest Rate, Stated Percentage		2.00%	2.00%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 2.40% Senior Notes, due 2020 [Member]
BHE Debt [Line Items]
Par value		$ 350
Total BHE Senior Debt		$ 349	$ 349
Debt Instrument, Interest Rate, Stated Percentage		2.40%	2.40%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 3.75%, Senior Notes, due 2023 [Member]
BHE Debt [Line Items]
Par value		$ 500
Total BHE Senior Debt		$ 498	$ 497
Debt Instrument, Interest Rate, Stated Percentage		3.75%	3.75%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 3.50% Senior Notes, due 2025 [Member]
BHE Debt [Line Items]
Par value		$ 400
Total BHE Senior Debt		$ 398	$ 397
Debt Instrument, Interest Rate, Stated Percentage		3.50%	3.50%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 8.48%, Senior Notes, due 2028 [Member]
BHE Debt [Line Items]
Par value		$ 301
Total BHE Senior Debt		$ 302	$ 477
Debt Instrument, Interest Rate, Stated Percentage		8.48%	8.48%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 6.125%, Senior Bonds, due 2036 [Member]
BHE Debt [Line Items]
Par value		$ 1,670
Total BHE Senior Debt		$ 1,660	$ 1,690
Debt Instrument, Interest Rate, Stated Percentage		6.125%	6.125%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 5.95%, Senior Bonds, due 2037 [Member]
BHE Debt [Line Items]
Par value		$ 550
Total BHE Senior Debt		$ 547	$ 547
Debt Instrument, Interest Rate, Stated Percentage		5.95%	5.95%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 6.50%, Senior Bonds, due 2037 [Member]
BHE Debt [Line Items]
Par value		$ 225
Total BHE Senior Debt		$ 222	$ 987
Debt Instrument, Interest Rate, Stated Percentage		6.50%	6.50%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 5.15%, Senior Notes, due 2043 [Member]
BHE Debt [Line Items]
Par value		$ 750
Total BHE Senior Debt		$ 739	$ 739
Debt Instrument, Interest Rate, Stated Percentage		5.15%	5.15%
Senior Notes [Member] | Berkshire Hathaway Energy [Member] | 4.50% Senior Notes, due 2045 [Member]
BHE Debt [Line Items]
Par value		$ 750
Total BHE Senior Debt		$ 737	$ 737
Debt Instrument, Interest Rate, Stated Percentage		4.50%	4.50%
Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member]
BHE Debt [Line Items]
Par value		$ 100
BHE junior subordinated debentures		$ 100	$ 944
Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due 2043 [Member]
BHE Debt [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		3.00%
Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due 2044 [Member]
BHE Debt [Line Items]
Par value		$ 0
BHE junior subordinated debentures		0	944
Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due June 2057 [Member]
BHE Debt [Line Items]
Par value		100
BHE junior subordinated debentures		100	$ 0
Interest Expense, Debt		$ 3
Basis Point Spread, Up To 3rd Anniversary Date [Member] | Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due 2043 [Member]
BHE Debt [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate
Basis Point Spread, 3rd Anniversary up to 7th Anniversary Date [Member] | Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due 2043 [Member]
BHE Debt [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate
Basis Point Spread, If 50% of principal is paid by 3rd Anniversary Date [Member] | Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due 2043 [Member]
BHE Debt [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate
Basis Point Spread, 7th Anniversary Date Until Maturity Date [Member] | Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due 2043 [Member]
BHE Debt [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate
Subsequent Event [Member] | Senior Notes [Member] | Berkshire Hathaway Energy [Member] | Senior Notes, 2.375%, due 2021 [Member]
BHE Debt [Line Items]
Par value					$ 450
Debt Instrument, Interest Rate, Stated Percentage					2.00%
Subsequent Event [Member] | Senior Notes [Member] | Berkshire Hathaway Energy [Member] | Senior Notes, 2.800%, due 2023 [Member]
BHE Debt [Line Items]
Par value					$ 400
Debt Instrument, Interest Rate, Stated Percentage					3.00%
Subsequent Event [Member] | Senior Notes [Member] | Berkshire Hathaway Energy [Member] | Senior Notes, 3.250%, due 2028 [Member]
BHE Debt [Line Items]
Par value					$ 600
Debt Instrument, Interest Rate, Stated Percentage					3.00%
Subsequent Event [Member] | Senior Notes [Member] | Berkshire Hathaway Energy [Member] | Senior Notes, 3.80%, due 2048 [Member]
BHE Debt [Line Items]
Par value					$ 750
Debt Instrument, Interest Rate, Stated Percentage					4.00%

Subsidiary Debt - Summary (Deta

Subsidiary Debt - Summary (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Long-term Debt		35,193	$ 36,116
Other Long-term Debt, Noncurrent		26,210	26,748
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other Long-term Debt, Current		2,431	606
Other Long-term Debt, Noncurrent		26,210	26,748
Other long-term debt		28,641	27,354
Subsidiary Debt [Member] | BHE Pipeline Group [Member]
Debt Instrument [Line Items]
Par value		800
Other long-term debt		796	990
Subsidiary Debt [Member] | Northern Powergrid Holdings [Member]
Debt Instrument [Line Items]
Par value	[1]	2,792
Other long-term debt		2,805	2,379
Subsidiary Debt [Member] | BHE Renewables [Member]
Debt Instrument [Line Items]
Par value		3,636
Other long-term debt		3,594	3,674
Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		7,061
Other long-term debt		7,025	7,079
Eligible Property Subject To Lien Of Mortgages		27,000
Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		5,319
Other long-term debt		5,259	4,592
Subsidiary Debt [Member] | HomeServices [Member]
Debt Instrument [Line Items]
Par value		247
Other long-term debt		247	0
Letters of credit supporting tax-exempt bond obligations [Member] | Letter of Credit [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		$ 216	$ 255
Maximum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.87%	0.86%
Minimum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.60%	0.69%
PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 7,005	$ 7,052
Eligible Property Subject To Lien Of Mortgages		27,000
PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		7,061
Other long-term debt		7,025	7,079
PacifiCorp [Member] | Letters of credit supporting tax-exempt bond obligations [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		216	255
MidAmerican Funding LLC [Member]
Debt Instrument [Line Items]
Long-term Debt		240	326
MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		5,080
Other long-term debt		5,043	4,301
Eligible Property Subject To Lien Of Mortgages		16,000
European Investment Bank loan, 2.073%, due 2025 [Member] | Subsidiary Debt [Member] | Northern Powergrid Holdings [Member]
Debt Instrument [Line Items]
Par value	[1]	68
Other long-term debt		$ 69	$ 62
Debt Instrument, Interest Rate, Stated Percentage		2.073%	2.073%
First Mortgage Bonds, 2.95% To 8.53%, Due 2021 To 2025 [Member] | Maximum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.53%	8.53%
First Mortgage Bonds, 2.95% To 8.53%, Due 2021 To 2025 [Member] | Minimum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.95%	2.95%
First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		$ 1,875
First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 1,872	$ 1,872
First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member] | PacifiCorp [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.53%	8.53%
First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member] | PacifiCorp [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.85%	3.85%
First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | Maximum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.23%	8.23%
First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | Minimum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.95%	2.95%
First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		$ 1,224
First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 1,218	$ 1,217
First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | PacifiCorp [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.27%	8.27%
First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | PacifiCorp [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.95%	2.95%
First Mortgage Bonds, 7.70%, Due 2031 [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.70%	7.70%
First Mortgage Bonds, 7.70%, Due 2031 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		$ 300
Debt Instrument, Interest Rate, Stated Percentage		7.70%	7.70%
First Mortgage Bonds, 7.70%, Due 2031 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 298	$ 298
First Mortgage Bonds, 5.25% To 6.10%, Due 2034 to 2036 [Member] | Maximum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.25%	6.25%
First Mortgage Bonds, 5.25% To 6.10%, Due 2034 to 2036 [Member] | Minimum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.25%	5.25%
First Mortgage Bonds, 5.25% To 6.10%, Due 2034 to 2036 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		$ 2,050
First Mortgage Bonds, 5.25% To 6.10%, Due 2034 to 2036 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 2,040	$ 2,039
First Mortgage Bonds, 5.25% To 6.10%, Due 2034 to 2036 [Member] | PacifiCorp [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.10%	6.10%
First Mortgage Bonds, 5.25% To 6.10%, Due 2034 to 2036 [Member] | PacifiCorp [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.25%	5.25%
First Mortgage Bonds, 5.75% To 6.35%, Due 2037 To 2039 [Member] | Maximum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.35%	6.35%
First Mortgage Bonds, 5.75% To 6.35%, Due 2037 To 2039 [Member] | Minimum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.10%	4.10%
First Mortgage Bonds, 5.75% To 6.35%, Due 2037 To 2039 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		$ 1,250
First Mortgage Bonds, 5.75% To 6.35%, Due 2037 To 2039 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 1,236	$ 1,235
First Mortgage Bonds, 5.75% To 6.35%, Due 2037 To 2039 [Member] | PacifiCorp [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.35%	6.35%
First Mortgage Bonds, 5.75% To 6.35%, Due 2037 To 2039 [Member] | PacifiCorp [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
Tax-exempt bond obligations, variable rate series, due 2017 to 2018 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		$ 79
Tax-exempt bond obligations, variable rate series, due 2017 to 2018 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		79	$ 91
Tax-exempt bond obligations, variable rate series, due 2018 to 2025 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value	[2]	70
Tax-exempt bond obligations, variable rate series, due 2018 to 2025 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt	[2]	70	108
Variable-rate tax-exempt obligation series due 2024 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value	[2],[3]	143
Variable-rate tax-exempt obligation series due 2024 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt	[2],[3]	142	142
Variable-rate tax-exempt obligation series due 2024 to 2025 [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value	[3]	50
Variable-rate tax-exempt obligation series due 2024 to 2025 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt	[3]	$ 50	$ 50
Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | Maximum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		14.61%	14.61%
Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | Minimum [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.75%	8.75%
Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | PacifiCorp [Member] | Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Capital Lease Obligations		$ 20	$ 27
Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | PacifiCorp [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		14.61%	14.61%
Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | PacifiCorp [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.75%	8.75%
Senior Notes, 6.927%, due 2029 [Member] | MidAmerican Funding LLC [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 239
Other long-term debt		$ 216	$ 291
Debt Instrument, Interest Rate, Stated Percentage		6.927%	6.927%
Tax-exempt bond obligations, variable rate, due 2016-2046 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.91%	0.76%
Par value		$ 370
Other long-term debt		368	$ 219
MEC First Mortgage Bonds, 2.40%, Due March 2019 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		500
Other long-term debt		$ 499	$ 499
Debt Instrument, Interest Rate, Stated Percentage		2.40%	2.40%
MEC First Mortgage Bonds, 3.70%, Due September 2023 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 250
Other long-term debt		$ 248	$ 248
Debt Instrument, Interest Rate, Stated Percentage		3.70%	3.70%
MEC First Mortgage Bonds, 3.50%, Due October 2024 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 500
Other long-term debt		$ 501	$ 501
Debt Instrument, Interest Rate, Stated Percentage		3.50%	3.50%
MEC First Mortgage Bonds, 3.10%, Due May 2027 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 375
Other long-term debt		$ 372	$ 0
Debt Instrument, Interest Rate, Stated Percentage		3.10%	3.10%
MEC First Mortgage Bonds, 4.80%, Due September 2043 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 350
Other long-term debt		$ 346	$ 345
Debt Instrument, Interest Rate, Stated Percentage		4.80%	4.80%
MEC First Mortgage Bonds, 4.40%, Due October 2044 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 400
Other long-term debt		$ 394	$ 394
Debt Instrument, Interest Rate, Stated Percentage		4.40%	4.40%
MEC First Mortgage Bonds, 4.25%, Due May 2046 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 450
Other long-term debt		$ 445	$ 445
Debt Instrument, Interest Rate, Stated Percentage		4.25%	4.25%
MEC Notes, 5.95% Series, due 2017 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 0
Other long-term debt		$ 0	$ 250
Debt Instrument, Interest Rate, Stated Percentage		5.95%	5.95%
MEC Notes, 6.75% Series, due 2031 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 400
Other long-term debt		$ 396	$ 396
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
MEC Notes, 5.75% Series, due 2035 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 300
Other long-term debt		$ 298	$ 298
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
MEC Notes, 5.8% Series, due 2036 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 350
Other long-term debt		$ 348	$ 347
Debt Instrument, Interest Rate, Stated Percentage		5.80%	5.80%
MEC Notes, 5.3% Series, due 2018 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 350
Other long-term debt		$ 350	$ 350
Debt Instrument, Interest Rate, Stated Percentage		5.30%	5.30%
MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 8
Other long-term debt		$ 6	$ 7
Vendor Financing, Discount Rate Applied			4.45%
MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member] | MidAmerican Energy Company [Member] | Maximum [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		4.45%
MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member] | MidAmerican Energy Company [Member] | Minimum [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		3.42%
Capital Lease Obligations, 4.16%, Due Through 2020 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 2
Other long-term debt		2	$ 2
MEC First Mortgage Bonds, 3.95%, Due 2047 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		475
Other long-term debt		$ 470	$ 0
Debt Instrument, Interest Rate, Stated Percentage		3.95%	3.95%
Secured Debt [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Par value		$ 180
Capital Lease Obligations, 4.16%, Due Through 2020 [Member] | MidAmerican Energy Company [Member] | Subsidiary Debt [Member] | MidAmerican Funding [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied		4.16%	4.16%
Kern River [Member] | Senior Notes, 4.893%, due 2018 [Member] | Subsidiary Debt [Member] | BHE Pipeline Group [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.893%	4.893%
[1]	(1)The par values for these debt instruments are denominated in sterling.
[2]	Supported by $216 million and $255 million of fully available letters of credit issued under committed bank arrangements as of December 31, 2017 and 2016, respectively.
[3]	Secured by pledged first mortgage bonds registered to and held by the tax-exempt bond trustee generally with the same interest rates, maturity dates and redemption provisions as the tax-exempt bond obligations.

Subsidiary Debt - NV Energy (De

Subsidiary Debt - NV Energy (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other long-term debt		28,641	$ 27,354
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	[1]	2,792
Other long-term debt		2,805	2,379
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | European Investment Bank loans, 2.564%, due 2027 [Member]
Debt Instrument [Line Items]
Par value	[1]	338
Other long-term debt		$ 336	$ 308
Debt Instrument, Interest Rate, Stated Percentage		2.564%	2.564%
MidAmerican Funding [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 5,319
Other long-term debt		5,259	$ 4,592
NV Energy [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		4,577
Other long-term debt		4,581	4,582
BHE Renewables [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		3,636
Other long-term debt		3,594	3,674
BHE Renewables [Member] | Subsidiary Debt [Member] | Marshall Wind term loan, variable interest rate, due 2026 [Member]
Debt Instrument [Line Items]
Par value	[2],[3]	88
Other long-term debt	[2],[3]	$ 86	$ 90
Debt Instrument, Interest Rate, Stated Percentage		3.212%	3.212%
BHE Renewables [Member] | Subsidiary Debt [Member] | Grande Prairie Wind, Senior Notes, 3.860%, due 2037 [Member]
Debt Instrument [Line Items]
Par value	[2]	$ 408
Other long-term debt		$ 404	$ 414
Debt Instrument, Interest Rate, Stated Percentage		5.375%	5.375%
BHE Renewables [Member] | Subsidiary Debt [Member] | Topaz Solar Farms Senior Notes, 4.875%, due September 2015 through September 2039 [Member]
Debt Instrument [Line Items]
Par value	[2]	$ 219
Other long-term debt	[2]	$ 217	$ 229
Debt Instrument, Interest Rate, Stated Percentage		4.875%	4.875%
BHE Renewables [Member] | Subsidiary Debt [Member] | Alamo 6, LLC Senior Secured Notes, 4.17%, due March 2018 through March 2042 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.17%	4.17%
HomeServices [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 247
Other long-term debt		$ 247	$ 0
HomeServices [Member] | Subsidiary Debt [Member] | Variable-rate Term Loan - Due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.819%	0.00%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 5,080
Other long-term debt		5,043	$ 4,301
Eligible Property Subject To Lien Of Mortgages		16,000
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | Tax-exempt bond obligations, variable rate, due 2023-2047 [Member]
Debt Instrument [Line Items]
Par value		370
Other long-term debt		$ 368	$ 219
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.91%	0.76%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.50%, Due October 2024 [Member]
Debt Instrument [Line Items]
Par value		$ 500
Other long-term debt		$ 501	$ 501
Debt Instrument, Interest Rate, Stated Percentage		3.50%	3.50%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 4.25%, Due May 2046 [Member]
Debt Instrument [Line Items]
Par value		$ 450
Other long-term debt		$ 445	$ 445
Debt Instrument, Interest Rate, Stated Percentage		4.25%	4.25%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.95%, Due 2047 [Member]
Debt Instrument [Line Items]
Par value		$ 475
Other long-term debt		$ 470	$ 0
Debt Instrument, Interest Rate, Stated Percentage		3.95%	3.95%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.10%, Due May 2027 [Member]
Debt Instrument [Line Items]
Par value		$ 375
Other long-term debt		$ 372	$ 0
Debt Instrument, Interest Rate, Stated Percentage		3.10%	3.10%
NV Energy, Inc. [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Senior Notes, 6.250%, due 2020 [Member]
Debt Instrument [Line Items]
Par value		$ 315
Other long-term debt		$ 337	$ 363
Debt Instrument, Interest Rate, Stated Percentage		6.25%	6.25%
Nevada Power Company [Member]
Debt Instrument [Line Items]
Par value		$ 3,107
Eligible Property Subject To Lien Of Mortgages		8,400
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series O due 2018 [Member]
Debt Instrument [Line Items]
Other long-term debt		324	$ 324
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series S due 2018 [Member]
Debt Instrument [Line Items]
Other long-term debt		499	498
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 7.125%, Series V due 2019 [Member]
Debt Instrument [Line Items]
Other long-term debt		499	499
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.650%, Series N due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		357	357
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.750%, Series R due 2037 [Member]
Debt Instrument [Line Items]
Other long-term debt		346	345
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.375%, Series X due 2040 [Member]
Debt Instrument [Line Items]
Other long-term debt		247	247
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.450%, Series Y due 2041 [Member]
Debt Instrument [Line Items]
Other long-term debt		236	236
Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.80%, Series 2017A, due 2032 [Member]
Debt Instrument [Line Items]
Other long-term debt	[4]	40	0
Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017, Due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt	[4]	39	0
Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017B, due 2039 [Member]
Debt Instrument [Line Items]
Other long-term debt	[4]	13	0
Nevada Power Company [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Other long-term debt		0	38
Nevada Power Company [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006 due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		0	37
Nevada Power Company [Member] | Subsidiary Debt [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Other long-term debt		475	$ 485
Nevada Power Company [Member] | NV Energy [Member] | Mortgage Securities, 6.500%, Series O due 2018 [Member]
Debt Instrument [Line Items]
Par value		324
Nevada Power Company [Member] | NV Energy [Member] | Mortgage Securities, 6.500%, Series S due 2018 [Member]
Debt Instrument [Line Items]
Par value		499
Nevada Power Company [Member] | NV Energy [Member] | Mortgage Securities, 7.125%, Series V due 2019 [Member]
Debt Instrument [Line Items]
Par value		500
Nevada Power Company [Member] | NV Energy [Member] | Mortgage Securities, 6.650%, Series N due 2036 [Member]
Debt Instrument [Line Items]
Par value		367
Nevada Power Company [Member] | NV Energy [Member] | Mortgage Securities, 6.750%, Series R due 2037 [Member]
Debt Instrument [Line Items]
Par value		349
Nevada Power Company [Member] | NV Energy [Member] | Mortgage Securities, 5.375%, Series X due 2040 [Member]
Debt Instrument [Line Items]
Par value		250
Nevada Power Company [Member] | NV Energy [Member] | Mortgage Securities, 5.450%, Series Y due 2041 [Member]
Debt Instrument [Line Items]
Par value		250
Nevada Power Company [Member] | NV Energy [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.80%, Series 2017A, due 2032 [Member]
Debt Instrument [Line Items]
Par value	[4]	40
Nevada Power Company [Member] | NV Energy [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017, Due 2036 [Member]
Debt Instrument [Line Items]
Par value	[4]	40
Nevada Power Company [Member] | NV Energy [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017B, due 2039 [Member]
Debt Instrument [Line Items]
Par value	[4]	$ 13
Debt Instrument, Interest Rate, Stated Percentage		1.60%	0.00%
Nevada Power Company [Member] | NV Energy [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Par value		$ 0
Nevada Power Company [Member] | NV Energy [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006 due 2036 [Member]
Debt Instrument [Line Items]
Par value		0
Nevada Power Company [Member] | NV Energy [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Par value		475
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		3,107
Other long-term debt		$ 3,088	$ 3,066
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series O due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.50%	6.50%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series S due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.50%	6.50%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage Securities, 7.125%, Series V due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.125%	7.125%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.650%, Series N due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 359
Debt Instrument, Interest Rate, Stated Percentage		6.65%	6.65%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.750%, Series R due 2037 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 348
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.375%, Series X due 2040 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 248
Debt Instrument, Interest Rate, Stated Percentage		5.375%	5.375%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.450%, Series Y due 2041 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 244
Debt Instrument, Interest Rate, Stated Percentage		5.45%	5.45%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.80%, Series 2017A, due 2032 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.80%	0.00%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017, Due 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.60%	0.00%
Nevada Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017B, due 2039 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.60%	0.00%
Nevada Power Company [Member] | Minimum [Member] | NV Energy [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		2.75%	2.75%
Nevada Power Company [Member] | Minimum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.89%
Nevada Power Company [Member] | Minimum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006 due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.89%
Nevada Power Company [Member] | Minimum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		2.75%	2.75%
Nevada Power Company [Member] | Maximum [Member] | NV Energy [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		11.60%	11.60%
Nevada Power Company [Member] | Maximum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.928%
Nevada Power Company [Member] | Maximum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006 due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.928%
Nevada Power Company [Member] | Maximum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		11.60%	11.60%
Sierra Pacific Power Company [Member]
Debt Instrument [Line Items]
Par value		$ 1,155
Eligible Property Subject To Lien Of Mortgages		$ 3,900
Sierra Pacific Power Company [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.375%	3.375%
Sierra Pacific Power Company [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 248	$ 248
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member]
Debt Instrument [Line Items]
Other long-term debt		396	395
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member]
Debt Instrument [Line Items]
Other long-term debt		255	255
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member]
Debt Instrument [Line Items]
Other long-term debt	[5]	20	20
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member]
Debt Instrument [Line Items]
Other long-term debt	[5]	58	58
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt	[6]	63	64
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		30	29
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		25	25
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		25	25
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Capital and financial lease obligations, 2.700% to 8.548%, due through 2054 [Member]
Debt Instrument [Line Items]
Other long-term debt		34	34
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Par value		250
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member]
Debt Instrument [Line Items]
Par value		400
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member]
Debt Instrument [Line Items]
Par value		252
Sierra Pacific Power Company [Member] | NV Energy [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member]
Debt Instrument [Line Items]
Par value	[5]	20
Sierra Pacific Power Company [Member] | NV Energy [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member]
Debt Instrument [Line Items]
Par value	[5]	59
Sierra Pacific Power Company [Member] | NV Energy [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member]
Debt Instrument [Line Items]
Par value	[6]	60
Sierra Pacific Power Company [Member] | NV Energy [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Par value		30
Sierra Pacific Power Company [Member] | NV Energy [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Par value		25
Sierra Pacific Power Company [Member] | NV Energy [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Par value		25
Sierra Pacific Power Company [Member] | NV Energy [Member] | Capital and financial lease obligations, 2.700% to 8.548%, due through 2054 [Member]
Debt Instrument [Line Items]
Par value		34
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		1,155
Other long-term debt		1,156	$ 1,153
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 249
Debt Instrument, Interest Rate, Stated Percentage		3.375%	3.375%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 396
Debt Instrument, Interest Rate, Stated Percentage		2.60%	2.60%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 256
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.25%	1.25%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.50%	1.50%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.00%	3.00%
Sierra Pacific Power Company [Member] | Minimum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.69%	0.788%
Sierra Pacific Power Company [Member] | Minimum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.69%	0.788%
Sierra Pacific Power Company [Member] | Minimum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.69%	0.788%
Sierra Pacific Power Company [Member] | Maximum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.84%	0.80%
Sierra Pacific Power Company [Member] | Maximum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.84%	0.80%
Sierra Pacific Power Company [Member] | Maximum [Member] | NV Energy [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.84%	0.80%
[1]	(1)The par values for these debt instruments are denominated in sterling.
[2]	(1)Amortizes quarterly or semiannually.
[3]	(2)The term loans have variable interest rates based on LIBOR plus a margin that varies during the terms of the agreements. The Company has entered into interest rate swaps that fix the interest rate on 75% of the Pinyon Pines outstanding debt and 100% of the TX Jumbo Road and Marshall Wind outstanding debt. The variable interest rate as of December 31, 2017 and 2016 was 3.32% and 2.62%, respectively, while the fixed interest rates as of December 31, 2017 and 2016 ranged from 3.21% to 3.63%.
[4]	(1) Subject to mandatory purchase by Nevada Power in May 2020 at which date the interest rate may be adjusted from time to time.
[5]	(2) Subject to mandatory purchase by Sierra Pacific in June 2019 at which date the interest rate may be adjusted from time to time.
[6]	(3) Subject to mandatory purchase by Sierra Pacific in June 2022 at which date the interest rate may be adjusted from time to time.

Subsidiary Debt - Northern Powe

Subsidiary Debt - Northern Powergrid (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other long-term debt		28,641	$ 27,354
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	[1]	2,792
Other long-term debt		2,805	2,379
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 8.875%, due 2020 [Member]
Debt Instrument [Line Items]
Par value	[1]	135
Other long-term debt		$ 144	$ 136
Debt Instrument, Interest Rate, Stated Percentage		8.875%	8.875%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 9.25%, due 2020 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 270
Other long-term debt		$ 279	$ 259
Debt Instrument, Interest Rate, Stated Percentage		9.25%	9.25%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | European Investment Bank loans, 3.901% to 4.586%, due 2018 to 2022 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 366
Other long-term debt		$ 366	$ 333
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | European Investment Bank loans, 3.901% to 4.586%, due 2018 to 2022 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.901%	3.901%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | European Investment Bank loans, 3.901% to 4.586%, due 2018 to 2022 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.586%	4.586%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 7.25%, due 2022 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 270
Other long-term debt		$ 279	$ 257
Debt Instrument, Interest Rate, Stated Percentage		7.25%	7.25%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 2.50%, due 2025 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 203
Other long-term debt		$ 200	$ 182
Debt Instrument, Interest Rate, Stated Percentage		2.50%	2.50%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | European Investment Bank loan, 2.073%, due 2025 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 68
Other long-term debt		$ 69	$ 62
Debt Instrument, Interest Rate, Stated Percentage		2.073%	2.073%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | European Investment Bank loans, 2.564%, due 2017 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 338
Other long-term debt		$ 336	$ 308
Debt Instrument, Interest Rate, Stated Percentage		2.564%	2.564%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 7.25%, due 2028 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 250
Other long-term debt		$ 256	$ 234
Debt Instrument, Interest Rate, Stated Percentage		7.25%	7.25%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 5.125%, due 2035 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 270
Other long-term debt		$ 267	$ 243
Debt Instrument, Interest Rate, Stated Percentage		5.125%	5.125%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 5.125%, due 2035 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 203
Other long-term debt		$ 200	$ 183
Debt Instrument, Interest Rate, Stated Percentage		5.125%	5.125%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Bonds, 4.375%, due 2032 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 203
Other long-term debt		$ 199	$ 182
Debt Instrument, Interest Rate, Stated Percentage		4.375%	4.375%
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member] | Variable-rate bond, due 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		2.27%
Par value	[1],[2]	$ 216
Other long-term debt	[2]	$ 210	$ 0
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.82%
[1]	(1)The par values for these debt instruments are denominated in sterling.
[2]	(2)Amortizes semiannually and the Company has entered into an interest rate swap that fixes the interest rate on 85% of the outstanding debt. The variable interest rate as of December 31, 2017 was 2.27% while the fixed interest rate was 2.82%.

Subsidiary Debt - BHE Pipeline

Subsidiary Debt - BHE Pipeline Group (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value	$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	28,780
Other long-term debt	28,641	$ 27,354
BHE Pipeline Group [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	800
Other long-term debt	796	990
Northern Natural Gas [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	800
Other long-term debt	796	795
Northern Natural Gas [Member] | Subsidiary Debt [Member] | Senior Notes, 5.75%, due 2018 [Member]
Debt Instrument [Line Items]
Par value	200
Other long-term debt	200	199
Northern Natural Gas [Member] | Subsidiary Debt [Member] | Senior Notes, 4.25%, due 2021 [Member]
Debt Instrument [Line Items]
Par value	200
Other long-term debt	199	199
Northern Natural Gas [Member] | Subsidiary Debt [Member] | Senior Bonds, 5.8%, due 2037 [Member]
Debt Instrument [Line Items]
Par value	150
Other long-term debt	149	149
Northern Natural Gas [Member] | Subsidiary Debt [Member] | Senior Bonds, 4.1%, due 2042 [Member]
Debt Instrument [Line Items]
Par value	250
Other long-term debt	248	248
Kern River [Member] | Subsidiary Debt [Member] | Kern River Senior Notes, 4.893%, Due 2018 [Member]
Debt Instrument [Line Items]
Par value	0
Other long-term debt	$ 0	$ 195
Kern River [Member] | BHE Pipeline Group [Member] | Subsidiary Debt [Member] | Kern River Senior Notes, 4.893%, Due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.89%
Extinguishment of Debt, Gain (Loss), Net of Tax	$ 5
Northern Natural Gas [Member] | BHE Pipeline Group [Member] | Subsidiary Debt [Member] | Senior Notes, 5.75%, due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.75%	5.75%
Northern Natural Gas [Member] | BHE Pipeline Group [Member] | Subsidiary Debt [Member] | Senior Notes, 4.25%, due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.25%	4.25%
Northern Natural Gas [Member] | BHE Pipeline Group [Member] | Subsidiary Debt [Member] | Senior Bonds, 5.8%, due 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.80%	5.80%
Northern Natural Gas [Member] | BHE Pipeline Group [Member] | Subsidiary Debt [Member] | Senior Bonds, 4.1%, due 2042 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.10%	4.10%

Subsidiary Debt Subsidiary Debt

Subsidiary Debt Subsidiary Debt - AltaLink (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other long-term debt		28,641	$ 27,354
ALP Investments [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	[1]	477
Other long-term debt		$ 481	$ 453
ALP Investments [Member] | Subsidiary Debt [Member] | Series 09-1 Senior Bonds, 5.207%, due 2016 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.207%	5.207%
ALP Investments [Member] | Subsidiary Debt [Member] | Series 12-1 Senior Bonds, 3.674%, due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.674%	3.674%
Par value	[1]	$ 159
Other long-term debt		$ 162	$ 153
ALP Investments [Member] | Subsidiary Debt [Member] | Series 13-1 Senior Bonds, 3.265%, due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.265%	3.265%
Par value	[1]	$ 159
Other long-term debt		$ 161	$ 152
ALP Investments [Member] | Subsidiary Debt [Member] | Series 15-1 Senior Bonds, 2.244%, due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.244%	2.244%
Par value	[1]	$ 159
Other long-term debt		158	$ 148
AltaLink, L.P. [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	[1]	3,858
Other long-term debt		$ 3,840	$ 3,592
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2008-1 Notes, 5.243%, due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.243%	5.243%
Par value	[1]	$ 159
Other long-term debt		$ 159	$ 148
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2013-2 Notes, 3.621%, due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.621%	3.621%
Par value	[1]	$ 100
Other long-term debt		$ 99	$ 93
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2012-2 Notes, 2.978%, due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.978%	2.978%
Par value	[1]	$ 219
Other long-term debt		$ 218	$ 204
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2013-4 Notes, 3.668%, due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.668%	3.668%
Par value	[1]	$ 398
Other long-term debt		$ 397	$ 371
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2014-1 Notes, 3.399%, due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.399%	3.399%
Par value	[1]	$ 278
Other long-term debt		$ 278	$ 260
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2016-1 Notes, 2.747%, due 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.747%	0.00%
Par value	[1]	$ 278
Other long-term debt		$ 277	$ 259
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2006-1 Notes, 5.249%, due 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.249%	5.249%
Par value	[1]	$ 119
Other long-term debt		$ 119	$ 111
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2010-1 Notes, 5.381%, due 2040 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.381%	5.381%
Par value	[1]	$ 100
Other long-term debt		$ 99	$ 93
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2010-2 Notes, 4.872%, due 2040 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.872%	4.872%
Par value	[1]	$ 119
Other long-term debt		$ 119	$ 111
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2011-1 Notes, 4.462%, due 2041 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.462%	4.462%
Par value	[1]	$ 219
Other long-term debt		$ 218	$ 204
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2012-1 Notes, 3.99%, due 2042 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.99%	3.99%
Par value	[1]	$ 418
Other long-term debt		$ 412	$ 385
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2013-3 Notes, 4.922%, due 2043 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.922%	4.922%
Par value	[1]	$ 278
Other long-term debt		$ 278	$ 260
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2014-3 Notes, 4.054%, due 2044 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.054%	4.054%
Par value	[1]	$ 235
Other long-term debt		$ 233	$ 218
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2015-1 Notes, 4.090%, due 2045 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.09%	4.09%
Par value	[1]	$ 278
Other long-term debt		$ 277	$ 259
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2016-2 Notes, 3.717%, due 2046 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.717%	0.00%
Par value	[1]	$ 358
Other long-term debt		$ 356	$ 333
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2013-1 Notes, 4.446%, due 2053 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.446%	4.446%
Par value	[1]	$ 199
Other long-term debt		$ 198	$ 186
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2014-2 Notes, 4.274%, due 2064 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.274%	4.274%
Par value	[1]	$ 103
Other long-term debt		$ 103	$ 97
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Construction Loan, 4.950%, due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.66%	0.00%
Par value	[1]	$ 13
Other long-term debt		13	$ 13
BHE Transmission [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	[1]	4,348
Other long-term debt		$ 4,334	$ 4,058
[1]	ns): Par Value(1) 2017 2016AltaLink Investments, L.P.: Series 12-1 Senior Bonds, 3.674%, due 2019$159 $162 $153Series 13-1 Senior Bonds, 3.265%, due 2020159 161 152Series 15-1 Senior Bonds, 2.244%, due 2022159 158 148Total AltaLink Investments, L.P.477 481 453 AltaLink, L.P.: Series 2008-1 Notes, 5.243%, due 2018159 159 148Series 2013-2 Notes, 3.621%, due 2020100 99 93Series 2012-2 Notes, 2.978%, due 2022219 218 204Series 2013-4 Notes, 3.668%, due 2023398 397 371Series 2014-1 Notes, 3.399%, due 2024278 278 260Series 2016-1 Notes, 2.747%, due 2026278 277 259Series 2006-1 Notes, 5.249%, due 2036119 119 111Series 2010-1 Notes, 5.381%, due 2040100 99 93Series 2010-2 Notes, 4.872%, due 2040119 119 111Series 2011-1 Notes, 4.462%, due 2041219 218 204Series 2012-1 Notes, 3.990%, due 2042418 412 385Series 2013-3 Notes, 4.922%, due 2043278 278 260Series 2014-3 Notes, 4.054%, due 2044235 233 218Series 2015-1 Notes, 4.090%, due 2045278 277 259Series 2016-2 Notes, 3.717%, due 2046358 356 333Series 2013-1 Notes, 4.446%, due 2053199 198 186Series 2014-2 Notes, 4.274%, due 2064103 103 97Total AltaLink, L.P.3,858 3,840 3,592 Other: Construction Loan, 5.660%, due 202013 13 13 Total BHE Transmission$4,348 $4,334 $4,058(1)The par values for these debt instruments are denominated in Canadian

Subsidiary Debt - BHE Renewable

Subsidiary Debt - BHE Renewables (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other long-term debt		28,641	$ 27,354
BHE Renewables [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		3,636
Other long-term debt		3,594	3,674
Extinguishment of Debt, Gain (Loss), Net of Tax		$ 15
BHE Renewables [Member] | Subsidiary Debt [Member] | Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		3.21%
BHE Renewables [Member] | Subsidiary Debt [Member] | Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		3.63%
BHE Renewables [Member] | Subsidiary Debt [Member] | CE Generation Bonds 7.416% due 2018 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 0
Other long-term debt	[1]	$ 0	$ 67
Debt Instrument, Interest Rate, Stated Percentage		7.416%	7.416%
BHE Renewables [Member] | Subsidiary Debt [Member] | Salton Sea Funding Corporation Bonds 7.475% due 2018 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 0
Other long-term debt	[1]	$ 0	$ 31
Debt Instrument, Interest Rate, Stated Percentage		7.475%	7.475%
BHE Renewables [Member] | Subsidiary Debt [Member] | Cordova Funding Corporation Bonds, 8.48% to 9.07%, due 2019 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 0
Other long-term debt	[1]	$ 0	$ 97
BHE Renewables [Member] | Subsidiary Debt [Member] | Cordova Funding Corporation Bonds, 8.48% to 9.07%, due 2019 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.48%	8.48%
BHE Renewables [Member] | Subsidiary Debt [Member] | Cordova Funding Corporation Bonds, 8.48% to 9.07%, due 2019 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		9.07%	9.07%
BHE Renewables [Member] | Subsidiary Debt [Member] | Bishop Hill Holdings Senior Notes, 5.125%, due 2032 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 94
Other long-term debt	[1]	$ 93	$ 99
Debt Instrument, Interest Rate, Stated Percentage		5.125%	5.125%
BHE Renewables [Member] | Subsidiary Debt [Member] | Solar Star Funding, LLC Series A Senior Secured Notes, 3.950%, due June 2035 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 314
Other long-term debt	[1]	$ 310	$ 311
Debt Instrument, Interest Rate, Stated Percentage		3.95%	3.95%
BHE Renewables [Member] | Subsidiary Debt [Member] | Solar Star Funding, LLC Series A Senior Secured Notes, 5.375%, due June 2016 through June 2035 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 975
Other long-term debt	[1]	965	$ 966
BHE Renewables [Member] | Subsidiary Debt [Member] | Grande Prairie Wind, Senior Notes, 3.860%, due 2037 [Member]
Debt Instrument [Line Items]
Par value	[1]	408
Other long-term debt		$ 404	$ 414
Debt Instrument, Interest Rate, Stated Percentage		5.375%	5.375%
BHE Renewables [Member] | Subsidiary Debt [Member] | Topaz Solar Farms Senior Notes, 5.75%, due 2039 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 755
Other long-term debt	[1]	$ 745	$ 780
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
BHE Renewables [Member] | Subsidiary Debt [Member] | Topaz Solar Farms Senior Notes, 4.875%, due 2039
Debt Instrument [Line Items]
Par value	[1]	$ 219
Other long-term debt	[1]	$ 217	$ 229
Debt Instrument, Interest Rate, Stated Percentage		4.875%	4.875%
BHE Renewables [Member] | Subsidiary Debt [Member] | Alamo 6, LLC Senior Secured Notes, 4.17%, due March 2018 through March 2042 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.17%	4.17%
BHE Renewables [Member] | Subsidiary Debt [Member] | Alamo 6 Senior Notes, 4.170%, due 2042 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 232
Other long-term debt	[1]	229	$ 0
BHE Renewables [Member] | Subsidiary Debt [Member] | Other debt obligations [Member]
Debt Instrument [Line Items]
Par value	[1]	19
Other long-term debt	[1]	19	22
BHE Renewables [Member] | Subsidiary Debt [Member] | Pinyon Pines I and II Term Loans, due 2019 [Member]
Debt Instrument [Line Items]
Par value	[1],[2]	334
Other long-term debt	[1],[2]	$ 333	$ 355
Variable interest rate		3.32%	2.62%
Debt Instrument, Interest Rate, Stated Percentage		3.32%	2.62%
BHE Renewables [Member] | Subsidiary Debt [Member] | Wailuku Special Purpose Revenue Bonds, 0.09% due 2021 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 0
Other long-term debt	[1]	$ 0	$ 7
Debt Instrument, Interest Rate, Stated Percentage		0.90%	0.90%
BHE Renewables [Member] | Subsidiary Debt [Member] | TX Jumbo Road Term Loan, 3.626% due 2025 [Member]
Debt Instrument [Line Items]
Par value	[1],[2]	$ 198
Other long-term debt	[1],[2]	$ 193	$ 206
Debt Instrument, Interest Rate, Stated Percentage		3.626%	3.626%
BHE Renewables [Member] | Subsidiary Debt [Member] | Marshall Wind term loan, variable interest rate, due 2026 [Member]
Debt Instrument [Line Items]
Par value	[1],[2]	$ 88
Other long-term debt	[1],[2]	$ 86	$ 90
Debt Instrument, Interest Rate, Stated Percentage		3.212%	3.212%
[1]	(1)Amortizes quarterly or semiannually.
[2]	(2)The term loans have variable interest rates based on LIBOR plus a margin that varies during the terms of the agreements. The Company has entered into interest rate swaps that fix the interest rate on 75% of the Pinyon Pines outstanding debt and 100% of the TX Jumbo Road and Marshall Wind outstanding debt. The variable interest rate as of December 31, 2017 and 2016 was 3.32% and 2.62%, respectively, while the fixed interest rates as of December 31, 2017 and 2016 ranged from 3.21% to 3.63%.

Subsidiary Debt - Maturity Sche

Subsidiary Debt - Maturity Schedule (Details) $ in Millions	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 3,431
Long-term Debt, Maturities, Repayments of Principal in Year Two	2,103
Long-term Debt, Maturities, Repayments of Principal in Year Three	1,674
Long-term Debt, Maturities, Repayments of Principal in Year Four	886
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,838
Long-term Debt, Maturities, Repayments of Principal after Year Five	25,444
Par value	35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	28,780
PacifiCorp [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	588
Long-term Debt, Maturities, Repayments of Principal in Year Two	351
Long-term Debt, Maturities, Repayments of Principal in Year Three	39
Long-term Debt, Maturities, Repayments of Principal in Year Four	425
Long-term Debt, Maturities, Repayments of Principal in Year Five	606
Long-term Debt, Maturities, Repayments of Principal after Year Five	5,052
Par value	7,061
MidAmerican Funding [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	350
Long-term Debt, Maturities, Repayments of Principal in Year Two	501
Long-term Debt, Maturities, Repayments of Principal in Year Three	2
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	4,466
Par value	5,319
NV Energy [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	844
Long-term Debt, Maturities, Repayments of Principal in Year Two	520
Long-term Debt, Maturities, Repayments of Principal in Year Three	336
Long-term Debt, Maturities, Repayments of Principal in Year Four	27
Long-term Debt, Maturities, Repayments of Principal in Year Five	28
Long-term Debt, Maturities, Repayments of Principal after Year Five	2,822
Par value	4,577
Northern Powergrid Holdings [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	66
Long-term Debt, Maturities, Repayments of Principal in Year Two	78
Long-term Debt, Maturities, Repayments of Principal in Year Three	483
Long-term Debt, Maturities, Repayments of Principal in Year Four	26
Long-term Debt, Maturities, Repayments of Principal in Year Five	501
Long-term Debt, Maturities, Repayments of Principal after Year Five	1,638
Par value	2,792	[1]
BHE Pipeline Group [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	200
Long-term Debt, Maturities, Repayments of Principal in Year Two	0
Long-term Debt, Maturities, Repayments of Principal in Year Three	0
Long-term Debt, Maturities, Repayments of Principal in Year Four	200
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	400
Par value	800
BHE Transmission [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	160
Long-term Debt, Maturities, Repayments of Principal in Year Two	160
Long-term Debt, Maturities, Repayments of Principal in Year Three	269
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	378
Long-term Debt, Maturities, Repayments of Principal after Year Five	3,381
Par value	4,348	[2]
BHE Renewables [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	209
Long-term Debt, Maturities, Repayments of Principal in Year Two	473
Long-term Debt, Maturities, Repayments of Principal in Year Three	168
Long-term Debt, Maturities, Repayments of Principal in Year Four	175
Long-term Debt, Maturities, Repayments of Principal in Year Five	172
Long-term Debt, Maturities, Repayments of Principal after Year Five	2,439
Par value	3,636
HomeServices [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	14
Long-term Debt, Maturities, Repayments of Principal in Year Two	20
Long-term Debt, Maturities, Repayments of Principal in Year Three	27
Long-term Debt, Maturities, Repayments of Principal in Year Four	33
Long-term Debt, Maturities, Repayments of Principal in Year Five	153
Long-term Debt, Maturities, Repayments of Principal after Year Five	0
Par value	247
Berkshire Hathaway Energy [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	1,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	0
Long-term Debt, Maturities, Repayments of Principal in Year Three	350
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	5,146
Par value	6,496
Berkshire Hathaway Energy [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	0
Long-term Debt, Maturities, Repayments of Principal in Year Two	0
Long-term Debt, Maturities, Repayments of Principal in Year Three	0
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	100
Par value	$ 100
[1]	(1)The par values for these debt instruments are denominated in sterling.
[2]	ns): Par Value(1) 2017 2016AltaLink Investments, L.P.: Series 12-1 Senior Bonds, 3.674%, due 2019$159 $162 $153Series 13-1 Senior Bonds, 3.265%, due 2020159 161 152Series 15-1 Senior Bonds, 2.244%, due 2022159 158 148Total AltaLink Investments, L.P.477 481 453 AltaLink, L.P.: Series 2008-1 Notes, 5.243%, due 2018159 159 148Series 2013-2 Notes, 3.621%, due 2020100 99 93Series 2012-2 Notes, 2.978%, due 2022219 218 204Series 2013-4 Notes, 3.668%, due 2023398 397 371Series 2014-1 Notes, 3.399%, due 2024278 278 260Series 2016-1 Notes, 2.747%, due 2026278 277 259Series 2006-1 Notes, 5.249%, due 2036119 119 111Series 2010-1 Notes, 5.381%, due 2040100 99 93Series 2010-2 Notes, 4.872%, due 2040119 119 111Series 2011-1 Notes, 4.462%, due 2041219 218 204Series 2012-1 Notes, 3.990%, due 2042418 412 385Series 2013-3 Notes, 4.922%, due 2043278 278 260Series 2014-3 Notes, 4.054%, due 2044235 233 218Series 2015-1 Notes, 4.090%, due 2045278 277 259Series 2016-2 Notes, 3.717%, due 2046358 356 333Series 2013-1 Notes, 4.446%, due 2053199 198 186Series 2014-2 Notes, 4.274%, due 2064103 103 97Total AltaLink, L.P.3,858 3,840 3,592 Other: Construction Loan, 5.660%, due 202013 13 13 Total BHE Transmission$4,348 $4,334 $4,058(1)The par values for these debt instruments are denominated in Canadian

Subsidiary Debt Subsidiary D132

Subsidiary Debt Subsidiary Debt - Pacificorp (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Long-term Debt		35,193	$ 36,116
Line of Credit Facility, Amounts Supported	[1]	594	457
PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt		7,005	7,052
Long-term Debt and Capital Lease Obligations, Principal Amount		7,061
Current portion of long-term debt and capital lease obligations		588	58
Long-term debt and capital lease obligations		6,437	7,021
Total long-term debt and capital lease obligations		7,025	7,079
Line of Credit Facility, Amounts Supported		130	142
Maximum amount of additional long-term debt approved by regulators		1,325
Eligible Property Subject To Lien Of Mortgages		27,000
Capital Leases, Balance Sheet, Assets by Major Class, Net		20	27
PacifiCorp [Member] | Tax exempt bond obligations and commodity contract collateral requirement [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		230	269
Line of Credit Facility, Amounts Supported		216	255
PacifiCorp [Member] | Letters of credit supporting tax-exempt bond obligations [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		216	$ 255
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member]
Debt Instrument [Line Items]
Par value		$ 1,875
Long-term Debt, Weighted Average Interest Rate, at Point in Time		4.80%	4.80%
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.85%	3.85%
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.53%	8.53%
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member]
Debt Instrument [Line Items]
Par value		$ 1,224
Long-term Debt, Weighted Average Interest Rate, at Point in Time		4.10%	4.10%
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.95%	2.95%
PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.27%	8.27%
PacifiCorp [Member] | First Mortgage Bonds, 7.70%, Due 2031 [Member]
Debt Instrument [Line Items]
Par value		$ 300
Long-term Debt, Weighted Average Interest Rate, at Point in Time		7.70%	7.70%
Debt Instrument, Interest Rate, Stated Percentage		7.70%	7.70%
PacifiCorp [Member] | First Mortgage Bonds, 5.25% To 6.25%, Due 2034 to 2037 [Member]
Debt Instrument [Line Items]
Par value		$ 2,050
Long-term Debt, Weighted Average Interest Rate, at Point in Time		5.90%	5.90%
PacifiCorp [Member] | First Mortgage Bonds, 5.25% To 6.25%, Due 2034 to 2037 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.25%	5.25%
PacifiCorp [Member] | First Mortgage Bonds, 5.25% To 6.25%, Due 2034 to 2037 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.10%	6.10%
PacifiCorp [Member] | First Mortgage Bonds, 4.10% To 6.35%, Due 2038 To 2042 [Member]
Debt Instrument [Line Items]
Par value		$ 1,250
Long-term Debt, Weighted Average Interest Rate, at Point in Time		5.60%	5.60%
PacifiCorp [Member] | First Mortgage Bonds, 4.10% To 6.35%, Due 2038 To 2042 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.75%	5.75%
PacifiCorp [Member] | First Mortgage Bonds, 4.10% To 6.35%, Due 2038 To 2042 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.35%	6.35%
PacifiCorp [Member] | Tax-exempt bond obligations, variable rate series, due 2018 to 2020 [Member]
Debt Instrument [Line Items]
Par value		$ 79
Long-term Debt, Weighted Average Interest Rate, at Point in Time		1.77%	0.85%
PacifiCorp [Member] | Tax-exempt bond obligations, variable rate series, due 2018 to 2025 [Member]
Debt Instrument [Line Items]
Par value	[2]	$ 70
Long-term Debt, Weighted Average Interest Rate, at Point in Time	[2]	1.81%	0.74%
PacifiCorp [Member] | Variable-rate tax-exempt obligation series due 2024 [Member]
Debt Instrument [Line Items]
Par value	[2],[3]	$ 143
Long-term Debt, Weighted Average Interest Rate, at Point in Time	[2],[3]	1.73%	0.70%
PacifiCorp [Member] | Variable-rate tax-exempt obligation series due 2024 to 2025 [Member]
Debt Instrument [Line Items]
Par value	[3]	$ 50
Long-term Debt, Weighted Average Interest Rate, at Point in Time	[3]	1.72%	0.80%
PacifiCorp [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Par value		$ 7,041
Long-term Debt		$ 7,005	$ 7,052
PacifiCorp [Member] | Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member]
Debt Instrument [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time		11.46%	11.09%
PacifiCorp [Member] | Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.75%	8.75%
PacifiCorp [Member] | Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		14.61%	14.61%
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 28,780
Other long-term debt		28,641	$ 27,354
Subsidiary Debt [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		7,061
Eligible Property Subject To Lien Of Mortgages		27,000
Other long-term debt		$ 7,025	$ 7,079
Subsidiary Debt [Member] | PacifiCorp [Member] | Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.60%	0.69%
Subsidiary Debt [Member] | PacifiCorp [Member] | Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		1.87%	0.86%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.53%, Due 2021 To 2025 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.95%	2.95%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.53%, Due 2021 To 2025 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.53%	8.53%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.95%	2.95%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.23%	8.23%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 7.70%, Due 2031 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.70%	7.70%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 5.25% To 6.25%, Due 2034 to 2037 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.25%	5.25%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 5.25% To 6.25%, Due 2034 to 2037 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.25%	6.25%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 4.10% To 6.35%, Due 2038 To 2042 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.10%	4.10%
Subsidiary Debt [Member] | PacifiCorp [Member] | First Mortgage Bonds, 4.10% To 6.35%, Due 2038 To 2042 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.35%	6.35%
Subsidiary Debt [Member] | PacifiCorp [Member] | Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.75%	8.75%
Subsidiary Debt [Member] | PacifiCorp [Member] | Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		14.61%	14.61%
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member]
Debt Instrument [Line Items]
Par value		$ 7,061
Other long-term debt		7,025	$ 7,079
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.53%, Due 2018 Through 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt		1,872	1,872
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | First Mortgage Bonds, 2.95% To 8.23%, Due 2023 To 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt		1,218	1,217
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | First Mortgage Bonds, 7.70%, Due 2031 [Member]
Debt Instrument [Line Items]
Long-term Debt		298	298
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | First Mortgage Bonds, 5.25% To 6.25%, Due 2034 to 2037 [Member]
Debt Instrument [Line Items]
Long-term Debt		2,040	2,039
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | First Mortgage Bonds, 4.10% To 6.35%, Due 2038 To 2042 [Member]
Debt Instrument [Line Items]
Long-term Debt		1,236	1,235
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | Tax-exempt bond obligations, variable rate series, due 2018 to 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt		79	91
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | Tax-exempt bond obligations, variable rate series, due 2018 to 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt	[2]	70	108
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | Variable-rate tax-exempt obligation series due 2024 [Member]
Debt Instrument [Line Items]
Long-term Debt	[2],[3]	142	142
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | Variable-rate tax-exempt obligation series due 2024 to 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt	[3]	50	50
Subsidiary Debt [Member] | PacifiCorp [Member] | PacifiCorp [Member] | Capital Lease Obligations, 8.75% To 14.61%, Due Through 2035 [Member]
Debt Instrument [Line Items]
Capital Lease Obligations		$ 20	$ 27
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.
[2]	Supported by $216 million and $255 million of fully available letters of credit issued under committed bank arrangements as of December 31, 2017 and 2016, respectively.
[3]	Secured by pledged first mortgage bonds registered to and held by the tax-exempt bond trustee generally with the same interest rates, maturity dates and redemption provisions as the tax-exempt bond obligations.

Subsidiary Debt Subsidiary D133

Subsidiary Debt Subsidiary Debt - PacifiCorp - Annual Payment on Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 3,431
Long-term Debt, Maturities, Repayments of Principal in Year Two	2,103
Long-term Debt, Maturities, Repayments of Principal in Year Three	1,674
Long-term Debt, Maturities, Repayments of Principal in Year Four	886
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,838
Long-term Debt, Maturities, Repayments of Principal after Year Five	25,444
Par value	35,376
Long-term Debt	35,193	$ 36,116
PacifiCorp [Member]
Debt Instrument [Line Items]
Long-term Debt and Capital Lease Obligations, Repayments of Principal in Next Twelve Months	590
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	354
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	41
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	426
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	607
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	5,060
Total Long-term Debt Maturities and Capital Leases Future Minimum Payments	7,078
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	(36)
Long-term Debt	7,005	7,052
Total long-term debt and capital lease obligations	7,025	$ 7,079
PacifiCorp [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	586
Long-term Debt, Maturities, Repayments of Principal in Year Two	350
Long-term Debt, Maturities, Repayments of Principal in Year Three	38
Long-term Debt, Maturities, Repayments of Principal in Year Four	420
Long-term Debt, Maturities, Repayments of Principal in Year Five	605
Long-term Debt, Maturities, Repayments of Principal after Year Five	5,042
Par value	7,041
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	(36)
Long-term Debt	7,005
PacifiCorp [Member] | Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Capital Leases, Future Minimum Payments Due, Next Twelve Months	4
Capital Leases, Future Minimum Payments Due in Two Years	4
Capital Leases, Future Minimum Payments Due in Three Years	3
Capital Leases, Future Minimum Payments Due in Four Years	6
Capital Leases, Future Minimum Payments Due in Five Years	2
Capital Leases, Future Minimum Payments Due Thereafter	18
Capital Leases, Future Minimum Payments Due	37
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	0
Capital Lease Obligations	$ 20

Subsidiary Debt Subsidiary D134

Subsidiary Debt Subsidiary Debt - MEC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 28, 2018	Dec. 01, 2017	Dec. 31, 2016	Dec. 01, 2016
Debt Instrument [Line Items]
Par value	$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	28,780
Other long-term debt	28,641			$ 27,354
MidAmerican Funding [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	5,319
Other long-term debt	5,259			4,592
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	5,080
Other long-term debt	5,043			4,301
Eligible Property Subject To Lien Of Mortgages	16,000
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 2.40%, Due March 2019 [Member]
Debt Instrument [Line Items]
Par value	500
Other long-term debt	$ 499			$ 499
Debt Instrument, Interest Rate, Stated Percentage	2.40%			2.40%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.70%, Due September 2023 [Member]
Debt Instrument [Line Items]
Par value	$ 250
Other long-term debt	$ 248			$ 248
Debt Instrument, Interest Rate, Stated Percentage	3.70%			3.70%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.50%, Due October 2024 [Member]
Debt Instrument [Line Items]
Par value	$ 500
Other long-term debt	$ 501			$ 501
Debt Instrument, Interest Rate, Stated Percentage	3.50%			3.50%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.10%, Due May 2027 [Member]
Debt Instrument [Line Items]
Par value	$ 375
Other long-term debt	$ 372			$ 0
Debt Instrument, Interest Rate, Stated Percentage	3.10%			3.10%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 4.80%, Due September 2043 [Member]
Debt Instrument [Line Items]
Par value	$ 350
Other long-term debt	$ 346			$ 345
Debt Instrument, Interest Rate, Stated Percentage	4.80%			4.80%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 4.40%, Due October 2044 [Member]
Debt Instrument [Line Items]
Par value	$ 400
Other long-term debt	$ 394			$ 394
Debt Instrument, Interest Rate, Stated Percentage	4.40%			4.40%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 4.25%, Due May 2046 [Member]
Debt Instrument [Line Items]
Par value	$ 450
Other long-term debt	$ 445			$ 445
Debt Instrument, Interest Rate, Stated Percentage	4.25%			4.25%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.95%, Due 2047 [Member]
Debt Instrument [Line Items]
Par value	$ 475
Other long-term debt	$ 470			$ 0
Debt Instrument, Interest Rate, Stated Percentage	3.95%			3.95%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 5.95% Series, due 2017 [Member]
Debt Instrument [Line Items]
Par value	$ 0
Other long-term debt	$ 0			$ 250
Debt Instrument, Interest Rate, Stated Percentage	5.95%			5.95%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 5.3% Series, due 2018 [Member]
Debt Instrument [Line Items]
Par value	$ 350
Other long-term debt	$ 350			$ 350
Debt Instrument, Interest Rate, Stated Percentage	5.30%			5.30%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 6.75% Series, due 2031 [Member]
Debt Instrument [Line Items]
Par value	$ 400
Other long-term debt	$ 396			$ 396
Debt Instrument, Interest Rate, Stated Percentage	6.75%			6.75%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 5.75% Series, due 2035 [Member]
Debt Instrument [Line Items]
Par value	$ 300
Other long-term debt	$ 298			$ 298
Debt Instrument, Interest Rate, Stated Percentage	5.75%			5.75%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Notes, 5.8% Series, due 2036 [Member]
Debt Instrument [Line Items]
Par value	$ 350
Other long-term debt	$ 348			$ 347
Debt Instrument, Interest Rate, Stated Percentage	5.80%			5.80%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Par value	$ 8
Other long-term debt	$ 6			$ 7
Vendor Financing, Discount Rate Applied				4.45%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | Capital Lease Obligations, 4.16%, Due Through 2020 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied	4.16%			4.16%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Par value	$ 180
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Maximum [Member] | Subsidiary Debt [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied	4.45%
MidAmerican Energy Company [Member] | MidAmerican Funding [Member] | Minimum [Member] | Subsidiary Debt [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied	3.42%
MidAmerican Energy Company [Member] | Subsequent Event [Member] | MidAmerican Funding [Member] | Subsidiary Debt [Member] | MEC First Mortgage Bonds, 3.65%, Due August 2048 [Member]
Debt Instrument [Line Items]
Par value		$ 700
Debt Instrument, Interest Rate, Stated Percentage		4.00%
MidAmerican Energy Company [Member]
Debt Instrument [Line Items]
Par value	$ 5,080
Other long-term debt	5,042			$ 4,301
Eligible Property Subject To Lien Of Mortgages	$ 16,000
MidAmerican Energy Company [Member] | Tax-exempt bond obligations, variable rate, due 2016-2046 [Member]
Debt Instrument [Line Items]
Variable interest rate	1.91%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 2.40%, Due March 2019 [Member]
Debt Instrument [Line Items]
Par value	$ 500
Other long-term debt	$ 499			$ 499
Debt Instrument, Interest Rate, Stated Percentage	2.40%			2.40%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.70%, Due September 2023 [Member]
Debt Instrument [Line Items]
Par value	$ 250
Other long-term debt	$ 248			$ 248
Debt Instrument, Interest Rate, Stated Percentage	3.70%			3.70%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.50%, Due October 2024 [Member]
Debt Instrument [Line Items]
Par value	$ 500
Other long-term debt	$ 501			$ 501
Debt Instrument, Interest Rate, Stated Percentage	3.50%			3.50%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.10%, Due May 2027 [Member]
Debt Instrument [Line Items]
Par value	$ 375
Other long-term debt	372			$ 0
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 4.80%, Due September 2043 [Member]
Debt Instrument [Line Items]
Par value	350
Other long-term debt	$ 346			$ 345
Debt Instrument, Interest Rate, Stated Percentage	4.80%			4.80%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 4.40%, Due October 2044 [Member]
Debt Instrument [Line Items]
Par value	$ 400
Other long-term debt	$ 394			$ 394
Debt Instrument, Interest Rate, Stated Percentage	4.40%			4.40%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 4.25%, Due May 2046 [Member]
Debt Instrument [Line Items]
Par value	$ 450
Other long-term debt	$ 445			$ 445
Debt Instrument, Interest Rate, Stated Percentage	4.25%			4.25%
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.95%, Due 2047 [Member]
Debt Instrument [Line Items]
Par value	$ 475
Other long-term debt	470			$ 0
MidAmerican Energy Company [Member] | MEC Notes, 5.95% Series, due 2017 [Member]
Debt Instrument [Line Items]
Par value	0
Other long-term debt	$ 0			$ 250
Debt Instrument, Interest Rate, Stated Percentage	5.95%			5.95%
MidAmerican Energy Company [Member] | MEC Notes, 5.3% Series, due 2018 [Member]
Debt Instrument [Line Items]
Par value	$ 350
Other long-term debt	$ 350			$ 350
Debt Instrument, Interest Rate, Stated Percentage	5.30%			5.30%
MidAmerican Energy Company [Member] | MEC Notes, 6.75% Series, due 2031 [Member]
Debt Instrument [Line Items]
Par value	$ 400
Other long-term debt	$ 396			$ 396
Debt Instrument, Interest Rate, Stated Percentage	6.75%			6.75%
MidAmerican Energy Company [Member] | MEC Notes, 5.75% Series, due 2035 [Member]
Debt Instrument [Line Items]
Par value	$ 300
Other long-term debt	$ 298			$ 298
Debt Instrument, Interest Rate, Stated Percentage	5.75%			5.75%
MidAmerican Energy Company [Member] | MEC Notes, 5.8% Series, due 2036 [Member]
Debt Instrument [Line Items]
Par value	$ 350
Other long-term debt	$ 347			$ 347
Debt Instrument, Interest Rate, Stated Percentage	5.80%			5.80%
MidAmerican Energy Company [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Par value	$ 8
Other long-term debt	6			$ 7
MidAmerican Energy Company [Member] | MEC Transmission Upgrade Obligation, 4.449%, Due Through 2035 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied				4.45%
MidAmerican Energy Company [Member] | Variable Rate Tax Exempt Obligation Series due 2023, issued 1993 [Member]
Debt Instrument [Line Items]
Par value	7
Other long-term debt	7			$ 7
MidAmerican Energy Company [Member] | Variable Rate Tax Exempt Obligation Series Due 2023, issued in 2008 [Member]
Debt Instrument [Line Items]
Par value	57
Other long-term debt	57			57
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series due 2024 [Member]
Debt Instrument [Line Items]
Par value	35
Other long-term debt	35			35
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2025 [Member]
Debt Instrument [Line Items]
Par value	13
Other long-term debt	13			13
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2036 [Member]
Debt Instrument [Line Items]
Par value	33
Other long-term debt	33			33
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2038 [Member]
Debt Instrument [Line Items]
Par value	45
Other long-term debt	45			45
MidAmerican Energy Company [Member] | Variable-rate tax-exempt obligation series, due 2046 [Member]
Debt Instrument [Line Items]
Par value	30				$ 30
Other long-term debt	29			29
MidAmerican Energy Company [Member] | Variable Rate Tax Exempt Obligation Series Due 2047 [Member]
Debt Instrument [Line Items]
Par value	150		$ 150
Other long-term debt	149			0
MidAmerican Energy Company [Member] | Capital Lease Obligations, 4.16%, Due Through 2020 [Member]
Debt Instrument [Line Items]
Par value	2
Other long-term debt	$ 2			$ 2
Debt Instrument, Interest Rate, Stated Percentage	4.16%
MidAmerican Energy Company [Member] | Tax-exempt bond obligations, variable rate, due 2016-2038 [Member]
Debt Instrument [Line Items]
Variable interest rate				0.76%
MidAmerican Energy Company [Member] | Committed Common Equity Percentage To Regulators [Member]
Debt Instrument [Line Items]
Common equity to total capitalization percentage	42.00%
MidAmerican Energy Company [Member] | Committed Common Equity Percentage To Regulators Beyond Companies Control [Member]
Debt Instrument [Line Items]
Common equity to total capitalization percentage below which reasonable efforts to maintain agreed to percentage is not required	39.00%
MidAmerican Energy Company [Member] | Dividend Restriction For Common Equity Commitment [Member]
Debt Instrument [Line Items]
Amount Available for Dividend Distribution without Affecting Capital Adequacy Requirements	$ 2,100
MidAmerican Energy Company [Member] | Common Equity Level To Total Capitalization [Member]
Debt Instrument [Line Items]
Common Equity Level To Total Capitalization	53.00%
MidAmerican Energy Company [Member] | Maximum [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied	4.45%
MidAmerican Energy Company [Member] | Minimum [Member] | MEC Transmission Upgrade Obligations, 4.45% and 3.42% Due Through 2035 and 2036 [Member]
Debt Instrument [Line Items]
Vendor Financing, Discount Rate Applied	3.42%
MidAmerican Energy Company [Member] | Subsequent Event [Member] | MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.65%, Due August 2048 [Member]
Debt Instrument [Line Items]
Par value		$ 700
Debt Instrument, Interest Rate, Stated Percentage		3.65%
MidAmerican Energy Company [Member] | Variable Rate Tax Exempt Obligation Series Due 2047 [Member]
Debt Instrument [Line Items]
Restricted Cash and Cash Equivalents, Current	$ 108

Subsidiary Debt Subsidiary D135

Subsidiary Debt Subsidiary Debt - MEC - Maturity Schedule (Details) $ in Millions	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 3,431
Long-term Debt, Maturities, Repayments of Principal in Year Two	2,103
Long-term Debt, Maturities, Repayments of Principal in Year Three	1,674
Long-term Debt, Maturities, Repayments of Principal in Year Four	886
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,838
Long-term Debt, Maturities, Repayments of Principal after Year Five	25,444
MidAmerican Energy Company [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	350
Long-term Debt, Maturities, Repayments of Principal in Year Two	501
Long-term Debt, Maturities, Repayments of Principal in Year Three	2
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 4,227

Subsidiary Debt - MidAmerican F

Subsidiary Debt - MidAmerican Funding (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Equity Restrictions		16,900
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other long-term debt		28,641	$ 27,354
BHE Renewables [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		3,636
Other long-term debt		3,594	3,674
BHE Renewables [Member] | Subsidiary Debt [Member] | Solar Star Funding, LLC Series A Senior Secured Notes, 3.950%, due June 2035 [Member]
Debt Instrument [Line Items]
Par value	[1]	314
Other long-term debt	[1]	$ 310	$ 311
Debt Instrument, Interest Rate, Stated Percentage		3.95%	3.95%
BHE Renewables [Member] | Subsidiary Debt [Member] | Marshall Wind term loan, variable interest rate, due 2026 [Member]
Debt Instrument [Line Items]
Par value	[1],[2]	$ 88
Other long-term debt	[1],[2]	$ 86	$ 90
Debt Instrument, Interest Rate, Stated Percentage		3.212%	3.212%
BHE Renewables [Member] | Subsidiary Debt [Member] | Pinyon Pines I and II Term Loans, due 2019 [Member]
Debt Instrument [Line Items]
Par value	[1],[2]	$ 334
Other long-term debt	[1],[2]	$ 333	$ 355
Debt Instrument, Interest Rate, Stated Percentage		3.32%	2.62%
Variable interest rate		3.32%	2.62%
BHE Renewables [Member] | Subsidiary Debt [Member] | Wailuku Special Purpose Revenue Bonds, 0.09% due 2021 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 0
Other long-term debt	[1]	$ 0	$ 7
Debt Instrument, Interest Rate, Stated Percentage		0.90%	0.90%
BHE Renewables [Member] | Subsidiary Debt [Member] | Grande Prairie Wind, Senior Notes, 3.860%, due 2037 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 408
Other long-term debt		$ 404	$ 414
Debt Instrument, Interest Rate, Stated Percentage		5.375%	5.375%
NV Energy, Inc. [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 4,577
Other long-term debt		4,581	$ 4,582
AltaLink, L.P. [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value	[3]	3,858
Other long-term debt		3,840	3,592
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2015-1 Notes, 4.090%, due 2045 [Member]
Debt Instrument [Line Items]
Par value	[3]	278
Other long-term debt		$ 277	$ 259
Debt Instrument, Interest Rate, Stated Percentage		4.09%	4.09%
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2014-1 Notes, 3.399%, due 2024 [Member]
Debt Instrument [Line Items]
Par value	[3]	$ 278
Other long-term debt		$ 278	$ 260
Debt Instrument, Interest Rate, Stated Percentage		3.399%	3.399%
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2014-2 Notes, 4.274%, due 2064 [Member]
Debt Instrument [Line Items]
Par value	[3]	$ 103
Other long-term debt		$ 103	$ 97
Debt Instrument, Interest Rate, Stated Percentage		4.274%	4.274%
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2016-1 Notes, 2.747%, due 2026 [Member]
Debt Instrument [Line Items]
Par value	[3]	$ 278
Other long-term debt		$ 277	$ 259
Debt Instrument, Interest Rate, Stated Percentage		2.747%	0.00%
AltaLink, L.P. [Member] | Subsidiary Debt [Member] | Series 2016-2 Notes, 3.717%, due 2046 [Member]
Debt Instrument [Line Items]
Par value	[3]	$ 358
Other long-term debt		$ 356	$ 333
Debt Instrument, Interest Rate, Stated Percentage		3.717%	0.00%
Sierra Pacific Power Company [Member]
Debt Instrument [Line Items]
Par value		$ 1,155
Eligible Property Subject To Lien Of Mortgages		$ 3,900
Sierra Pacific Power Company [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.375%	3.375%
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member]
Debt Instrument [Line Items]
Other long-term debt	[4]	$ 20	$ 20
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member]
Debt Instrument [Line Items]
Other long-term debt		396	395
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Other long-term debt		248	248
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member]
Debt Instrument [Line Items]
Other long-term debt	[4]	58	58
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt	[5]	63	64
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		30	29
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		25	25
Sierra Pacific Power Company [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		25	25
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member]
Debt Instrument [Line Items]
Par value	[4]	20
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member]
Debt Instrument [Line Items]
Par value		400
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Par value		250
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member]
Debt Instrument [Line Items]
Par value	[4]	59
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member]
Debt Instrument [Line Items]
Par value	[5]	60
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Par value		30
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Par value		25
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Par value		25
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		1,155
Other long-term debt		$ 1,156	$ 1,153
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.25%	1.25%
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 396
Debt Instrument, Interest Rate, Stated Percentage		2.60%	2.60%
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 249
Debt Instrument, Interest Rate, Stated Percentage		3.375%	3.375%
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.50%	1.50%
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.00%	3.00%
MidAmerican Funding, LLC and Subsidiaries [Domain]
Debt Instrument [Line Items]
Equity Restrictions		$ 3,700
MidAmerican Funding LLC [Member] | Senior Notes, 6.927%, due 2029 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Gain (Loss), Net of Tax		29
MidAmerican Funding LLC [Member] | MidAmerican Funding LLC [Member] | Senior Notes, 6.927%, due 2029 [Member]
Debt Instrument [Line Items]
Par value		239
Other long-term debt		$ 240	$ 326
Debt Instrument, Interest Rate, Stated Percentage		6.927%
Minimum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2031 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.69%	0.788%
Minimum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.69%	0.788%
Minimum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.69%	0.788%
Minimum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.69%	0.788%
Maximum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2031 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.84%	0.80%
Maximum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.84%	0.80%
Maximum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.84%	0.80%
Maximum [Member] | Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member] | Subsidiary Debt [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Variable interest rate		1.84%	0.80%
[1]	(1)Amortizes quarterly or semiannually.
[2]	(2)The term loans have variable interest rates based on LIBOR plus a margin that varies during the terms of the agreements. The Company has entered into interest rate swaps that fix the interest rate on 75% of the Pinyon Pines outstanding debt and 100% of the TX Jumbo Road and Marshall Wind outstanding debt. The variable interest rate as of December 31, 2017 and 2016 was 3.32% and 2.62%, respectively, while the fixed interest rates as of December 31, 2017 and 2016 ranged from 3.21% to 3.63%.
[3]	ns): Par Value(1) 2017 2016AltaLink Investments, L.P.: Series 12-1 Senior Bonds, 3.674%, due 2019$159 $162 $153Series 13-1 Senior Bonds, 3.265%, due 2020159 161 152Series 15-1 Senior Bonds, 2.244%, due 2022159 158 148Total AltaLink Investments, L.P.477 481 453 AltaLink, L.P.: Series 2008-1 Notes, 5.243%, due 2018159 159 148Series 2013-2 Notes, 3.621%, due 2020100 99 93Series 2012-2 Notes, 2.978%, due 2022219 218 204Series 2013-4 Notes, 3.668%, due 2023398 397 371Series 2014-1 Notes, 3.399%, due 2024278 278 260Series 2016-1 Notes, 2.747%, due 2026278 277 259Series 2006-1 Notes, 5.249%, due 2036119 119 111Series 2010-1 Notes, 5.381%, due 2040100 99 93Series 2010-2 Notes, 4.872%, due 2040119 119 111Series 2011-1 Notes, 4.462%, due 2041219 218 204Series 2012-1 Notes, 3.990%, due 2042418 412 385Series 2013-3 Notes, 4.922%, due 2043278 278 260Series 2014-3 Notes, 4.054%, due 2044235 233 218Series 2015-1 Notes, 4.090%, due 2045278 277 259Series 2016-2 Notes, 3.717%, due 2046358 356 333Series 2013-1 Notes, 4.446%, due 2053199 198 186Series 2014-2 Notes, 4.274%, due 2064103 103 97Total AltaLink, L.P.3,858 3,840 3,592 Other: Construction Loan, 5.660%, due 202013 13 13 Total BHE Transmission$4,348 $4,334 $4,058(1)The par values for these debt instruments are denominated in Canadian
[4]	(2) Subject to mandatory purchase by Sierra Pacific in June 2019 at which date the interest rate may be adjusted from time to time.
[5]	(3) Subject to mandatory purchase by Sierra Pacific in June 2022 at which date the interest rate may be adjusted from time to time.

Subsidiary Debt Subsidiary D137

Subsidiary Debt Subsidiary Debt - NPC - Capital and Financial Lease Obligations (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other long-term debt		28,641	$ 27,354
Nevada Power Company [Member]
Debt Instrument [Line Items]
Par value		3,107
Total Long-term Debt and Capital and Financial Lease Obligations		3,075	3,066
Long-term Debt and Capital and Financial Lease Obligations, Current		842	17
Long-term Debt and Capital and Financial Lease Obligations		2,233	3,049
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series O due 2018 [Member]
Debt Instrument [Line Items]
Other long-term debt		324	324
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series S due 2018 [Member]
Debt Instrument [Line Items]
Other long-term debt		499	498
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 7.125%, Series V due 2019 [Member]
Debt Instrument [Line Items]
Other long-term debt		499	499
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.650%, Series N due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		357	357
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.750%, Series R due 2037 [Member]
Debt Instrument [Line Items]
Other long-term debt		346	345
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.375%, Series X due 2040 [Member]
Debt Instrument [Line Items]
Other long-term debt		247	247
Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.450%, Series Y due 2041 [Member]
Debt Instrument [Line Items]
Other long-term debt		236	236
Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.80%, Series 2017A, due 2032 [Member]
Debt Instrument [Line Items]
Other long-term debt	[1]	40	0
Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017, Due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt	[1]	39	0
Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017B, due 2039 [Member]
Debt Instrument [Line Items]
Other long-term debt	[1]	13	0
Nevada Power Company [Member] | Subsidiary Debt [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Other long-term debt		0	38
Nevada Power Company [Member] | Subsidiary Debt [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Other long-term debt		475	485
NV Energy [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		4,577
Other long-term debt		4,581	$ 4,582
NV Energy [Member] | Nevada Power Company [Member] | Mortgage Securities, 6.500%, Series O due 2018 [Member]
Debt Instrument [Line Items]
Par value		324
NV Energy [Member] | Nevada Power Company [Member] | Mortgage Securities, 6.500%, Series S due 2018 [Member]
Debt Instrument [Line Items]
Par value		499
NV Energy [Member] | Nevada Power Company [Member] | Mortgage Securities, 7.125%, Series V due 2019 [Member]
Debt Instrument [Line Items]
Par value		500
NV Energy [Member] | Nevada Power Company [Member] | Mortgage Securities, 6.650%, Series N due 2036 [Member]
Debt Instrument [Line Items]
Par value		367
NV Energy [Member] | Nevada Power Company [Member] | Mortgage Securities, 6.750%, Series R due 2037 [Member]
Debt Instrument [Line Items]
Par value		349
NV Energy [Member] | Nevada Power Company [Member] | Mortgage Securities, 5.375%, Series X due 2040 [Member]
Debt Instrument [Line Items]
Par value		250
NV Energy [Member] | Nevada Power Company [Member] | Mortgage Securities, 5.450%, Series Y due 2041 [Member]
Debt Instrument [Line Items]
Par value		250
NV Energy [Member] | Nevada Power Company [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.80%, Series 2017A, due 2032 [Member]
Debt Instrument [Line Items]
Par value	[1]	40
NV Energy [Member] | Nevada Power Company [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017, Due 2036 [Member]
Debt Instrument [Line Items]
Par value	[1]	40
NV Energy [Member] | Nevada Power Company [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017B, due 2039 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 13
Debt Instrument, Interest Rate, Stated Percentage		1.60%	0.00%
NV Energy [Member] | Nevada Power Company [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Par value		$ 0
NV Energy [Member] | Nevada Power Company [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Par value		$ 475
NV Energy [Member] | Nevada Power Company [Member] | Minimum [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		2.75%	2.75%
NV Energy [Member] | Nevada Power Company [Member] | Maximum [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		11.60%	11.60%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 3,107
Other long-term debt		$ 3,088	$ 3,066
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series O due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.50%	6.50%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.500%, Series S due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.50%	6.50%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 7.125%, Series V due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		7.125%	7.125%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.650%, Series N due 2036 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 359
Debt Instrument, Interest Rate, Stated Percentage		6.65%	6.65%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 6.750%, Series R due 2037 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 348
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.375%, Series X due 2040 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 248
Debt Instrument, Interest Rate, Stated Percentage		5.375%	5.375%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Mortgage Securities, 5.450%, Series Y due 2041 [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 244
Debt Instrument, Interest Rate, Stated Percentage		5.45%	5.45%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.80%, Series 2017A, due 2032 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.80%	0.00%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017, Due 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.60%	0.00%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | NPC Pollution Control Refunding Revenue Bonds, 1.60%, Series 2017B, due 2039 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.60%	0.00%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Minimum [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.89%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Minimum [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006 due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.89%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Minimum [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		2.75%	2.75%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Maximum [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006A due 2032 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.928%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Maximum [Member] | Pollution Control Revenue Bonds, Variable-Rate, Series 2006 due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		0.00%	1.928%
NV Energy [Member] | Nevada Power Company [Member] | Subsidiary Debt [Member] | Maximum [Member] | Capital lease obligations, 2.75% to 11.60%, due through 2054 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		11.60%	11.60%
[1]	(1) Subject to mandatory purchase by Nevada Power in May 2020 at which date the interest rate may be adjusted from time to time.

Subsidiary Debt Subsidiary D138

Subsidiary Debt Subsidiary Debt - NPC - Annual Payment on Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 3,431
Long-term Debt, Maturities, Repayments of Principal in Year Two	2,103
Long-term Debt, Maturities, Repayments of Principal in Year Three	1,674
Long-term Debt, Maturities, Repayments of Principal in Year Four	886
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,838
Long-term Debt, Maturities, Repayments of Principal after Year Five	25,444
Par value	35,376
Long-term Debt	35,193	$ 36,116
Nevada Power Company [Member]
Debt Instrument [Line Items]
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Next Twelve Months	898
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Two	576
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Three	76
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Four	80
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Five	75
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal Thereafter	2,069
Par value	3,107
Total Long-term Debt Maturities and Capital and Financial Leases Future Minimum Payments	3,774
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	32
Executory costs	92
Capital and Financial Leases, Future Minimum Payments, Interest Included in Payments	575
Long-term Debt	2,600	$ 2,581
Long-term Debt and Capital and Financial Lease Obligations, Including Current Maturities	3,075
Nevada Power Company [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	823
Long-term Debt, Maturities, Repayments of Principal in Year Two	500
Long-term Debt, Maturities, Repayments of Principal in Year Three	0
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	1,309
Par value	2,632
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	32
Executory costs	0
Capital and Financial Leases, Future Minimum Payments, Interest Included in Payments	0
Long-term Debt	2,600
Nevada Power Company [Member] | Capital and Financial Lease Obligations [Member]
Debt Instrument [Line Items]
Capital and Financial Leases, Future Minimum Payments Due, Next Twelve Months	75
Capital and Financial Leases, Future Minimum Payments Due in Two Years	76
Capital and Financial Leases, Future Minimum Payments Due in Three Years	76
Capital and Financial Leases, Future Minimum Payments Due in Four Years	80
Capital and Financial Leases, Future Minimum Payments Due in Five Years	75
Capital and Financial Leases, Future Minimum Payments Due Thereafter	760
Capital and Financial Leases, Future Minimum Payments Due	1,142
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	0
Executory costs	92
Capital and Financial Leases, Future Minimum Payments, Interest Included in Payments	575
Capital and Financial Lease Obligations	$ 475

Subsidiary Debt Subsidiary D139

Subsidiary Debt Subsidiary Debt - NPC - (Details) - Nevada Power Company [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)option	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Eligible Property Subject To Lien Of Mortgages	$ 8,400
Building [Member]
Debt Instrument [Line Items]
Terms Of Capital Lease	30 years
Renewal Options Under Capital Lease, Number | option	5
Number Of Years In Renewal Period	5 years
Number Of Renewal Options Exercised Under Capital Lease | option	3
Number Of Additional Renewal Options Under Capital Lease | option	2
Extended Additional Term Of Capital Lease	10 years
Capital Leased Assets, Gross	$ 24	$ 25
Land and Building [Member]
Debt Instrument [Line Items]
Terms Of Capital Lease	20 years
Renewal Options Under Capital Lease, Number | option	3
Number Of Years In Renewal Period	10 years
Capital Leased Assets, Gross	$ 6	7
Long-Term Energy Purchase Contracts [Member]
Debt Instrument [Line Items]
Number Of Years In Renewal Period	30 years
Capital Leased Assets, Gross	$ 34	38
Equipment [Member]
Debt Instrument [Line Items]
Terms Of Capital Lease	7 years
Capital Leased Assets, Gross	$ 3	1
ON Line Transmission Line [Member]
Debt Instrument [Line Items]
Terms Of Capital Lease	41 years
Capital Leased Assets, Gross	$ 396	$ 402
Utilities Aggregate Share Transmission Line Project	25.00%
Remaining Share Transmission Line Project	75.00%
Nevada Power Company [Member] | ON Line Transmission Line [Member]
Debt Instrument [Line Items]
Utilities Aggregate Share Transmission Line Project	95.00%
Sierra Pacific Power Company [Member] | ON Line Transmission Line [Member]
Debt Instrument [Line Items]
Utilities Aggregate Share Transmission Line Project	5.00%

Subsidiary Debt Subsidiary D140

Subsidiary Debt Subsidiary Debt - SPPC - Capital and Financial Lease Obligations (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
Other long-term debt		28,641	$ 27,354
NV Energy [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		4,577
Other long-term debt		4,581	4,582
Sierra Pacific Power Company [Member]
Debt Instrument [Line Items]
Par value		1,155
Total Long-term Debt and Capital and Financial Lease Obligations		1,154	1,153
Long-term Debt and Capital and Financial Lease Obligations, Current		2	1
Long-term Debt and Capital and Financial Lease Obligations		1,152	1,152
Long-term Debt and Capital and Financial Lease Obligations, Including Current Maturities		$ 1,154	$ 1,153
Sierra Pacific Power Company [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.375%	3.375%
Sierra Pacific Power Company [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 248	$ 248
Sierra Pacific Power Company [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 396	$ 395
Sierra Pacific Power Company [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
Sierra Pacific Power Company [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 255	$ 255
Sierra Pacific Power Company [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt	[1]	20	20
Sierra Pacific Power Company [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt	[1]	58	58
Sierra Pacific Power Company [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt	[2]	63	64
Sierra Pacific Power Company [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		30	29
Sierra Pacific Power Company [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		25	25
Sierra Pacific Power Company [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 25	$ 25
Sierra Pacific Power Company [Member] | Minimum [Member] | Capital and financial lease obligations, 2.700% to 8.548%, due through 2054 [Member]
Debt Instrument [Line Items]
Variable interest rate		2.70%	2.70%
Sierra Pacific Power Company [Member] | Maximum [Member] | Capital and financial lease obligations, 2.700% to 8.548%, due through 2054 [Member]
Debt Instrument [Line Items]
Variable interest rate		10.396%	10.13%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 1,155
Other long-term debt		1,156	$ 1,153
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member]
Debt Instrument [Line Items]
Par value		250
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 3.375%, Series T due 2023 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 249
Debt Instrument, Interest Rate, Stated Percentage		3.375%	3.375%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member]
Debt Instrument [Line Items]
Par value		$ 400
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 2.600%, Series U due 2026 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 396
Debt Instrument, Interest Rate, Stated Percentage		2.60%	2.60%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member]
Debt Instrument [Line Items]
Par value		$ 252
Sierra Pacific Power Company [Member] | NV Energy [Member] | Mortgage securities, 6.750%, Series P due 2037 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Other long-term debt		$ 256
Debt Instrument, Interest Rate, Stated Percentage		6.75%	6.75%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 20
Sierra Pacific Power Company [Member] | NV Energy [Member] | Pollution Control Refunding Revenue Bonds, 1.250%, Series 2016A, due 2029 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.25%	1.25%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member]
Debt Instrument [Line Items]
Par value	[1]	$ 59
Sierra Pacific Power Company [Member] | NV Energy [Member] | Gas facilities refunding revenue bonds, 1.500%, series 2016A, due 2031 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.50%	1.50%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member]
Debt Instrument [Line Items]
Par value	[2]	$ 60
Sierra Pacific Power Company [Member] | NV Energy [Member] | Gas and water facilities refunding revenue bonds, 3.000% series 2016B, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.00%	3.00%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member]
Debt Instrument [Line Items]
Par value		$ 30
Sierra Pacific Power Company [Member] | NV Energy [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member]
Debt Instrument [Line Items]
Par value		25
Sierra Pacific Power Company [Member] | NV Energy [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member]
Debt Instrument [Line Items]
Par value		$ 25
Sierra Pacific Power Company [Member] | NV Energy [Member] | Minimum [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		1.69%	0.788%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Minimum [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		1.69%	0.788%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Minimum [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		1.69%	0.788%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Minimum [Member] | Capital and financial lease obligations, 2.700% to 8.548%, due through 2054 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		2.70%	2.70%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Maximum [Member] | Water facilities refunding revenue bonds, series 2016C, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		1.84%	0.80%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Maximum [Member] | Water facilities refunding revenue bonds, series 2016D, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		1.84%	0.80%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Maximum [Member] | Water facilities refunding revenue bonds, series 2016E, due 2036 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		1.84%	0.80%
Sierra Pacific Power Company [Member] | NV Energy [Member] | Maximum [Member] | Capital and financial lease obligations, 2.700% to 8.548%, due through 2054 [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Variable interest rate		10.396%	10.13%
[1]	(2) Subject to mandatory purchase by Sierra Pacific in June 2019 at which date the interest rate may be adjusted from time to time.
[2]	(3) Subject to mandatory purchase by Sierra Pacific in June 2022 at which date the interest rate may be adjusted from time to time.

Subsidiary Debt Subsidiary D141

Subsidiary Debt Subsidiary Debt - SPPC - Annual Payment on Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 3,431
Long-term Debt, Maturities, Repayments of Principal in Year Two	2,103
Long-term Debt, Maturities, Repayments of Principal in Year Three	1,674
Long-term Debt, Maturities, Repayments of Principal in Year Four	886
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,838
Long-term Debt, Maturities, Repayments of Principal after Year Five	25,444
Par value	35,376
Long-term Debt	35,193	$ 36,116
Sierra Pacific Power Company [Member]
Debt Instrument [Line Items]
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Next Twelve Months	4
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Two	4
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Three	4
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Four	4
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal in Year Five	3
Long-term Debt and Capital and Financial Lease Obligations, Repayments of Principal Thereafter	1,168
Par value	1,155
Total Long-term Debt Maturities and Capital and Financial Leases Future Minimum Payments	1,187
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	(1)
Capital and Financial Leases, Future Minimum Payments, Interest Included in Payments	(32)
Long-term Debt	1,120	1,119
Long-term Debt and Capital and Financial Lease Obligations, Including Current Maturities	1,154	$ 1,153
Eligible Property Subject To Lien Of Mortgages	3,900
Sierra Pacific Power Company [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	0
Long-term Debt, Maturities, Repayments of Principal in Year Two	0
Long-term Debt, Maturities, Repayments of Principal in Year Three	0
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	1,121
Par value	1,121
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	(1)
Capital and Financial Leases, Future Minimum Payments, Interest Included in Payments	0
Long-term Debt	1,120
Sierra Pacific Power Company [Member] | Capital and Financial Lease Obligations [Member]
Debt Instrument [Line Items]
Capital and Financial Leases, Future Minimum Payments Due, Next Twelve Months	4
Capital and Financial Leases, Future Minimum Payments Due in Two Years	4
Capital and Financial Leases, Future Minimum Payments Due in Three Years	4
Capital and Financial Leases, Future Minimum Payments Due in Four Years	4
Capital and Financial Leases, Future Minimum Payments Due in Five Years	3
Capital and Financial Leases, Future Minimum Payments Due Thereafter	47
Capital and Financial Leases, Future Minimum Payments Due	66
Debt Instrument, Unamortized Premium, Discount and Debt Issuance Cost	0
Capital and Financial Leases, Future Minimum Payments, Interest Included in Payments	(32)
Capital and Financial Lease Obligations	$ 34

Subsidiary Debt Subsidiary D142

Subsidiary Debt Subsidiary Debt - SPPC (Details) - Sierra Pacific Power Company [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Equipment [Member]
Debt Instrument [Line Items]
Terms Of Capital Lease	7 years
Capital Leased Assets, Gross	$ 3	$ 3
ON Line Transmission Line [Member]
Debt Instrument [Line Items]
Terms Of Capital Lease	41 years
Capital Leased Assets, Gross	$ 21	21
Utilities Aggregate Share Transmission Line Project	25.00%
Remaining Share Transmission Line Project	75.00%
Solar Generating Facility [Member]
Debt Instrument [Line Items]
Terms Of Capital Lease	20 years
Capital Leased Assets, Gross	$ 9	$ 10
Sierra Pacific Power Company [Member] | ON Line Transmission Line [Member]
Debt Instrument [Line Items]
Utilities Aggregate Share Transmission Line Project	5.00%
Nevada Power Company [Member] | ON Line Transmission Line [Member]
Debt Instrument [Line Items]
Utilities Aggregate Share Transmission Line Project	95.00%

Subsidiary Debt Subsidiary D143

Subsidiary Debt Subsidiary Debt - HomeServices (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par value		$ 35,376
Long-term Debt		35,193	$ 36,116
Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		28,780
HomeServices [Member] | Variable-rate Term Loan - Due 2022 [Member]
Debt Instrument [Line Items]
Par value	[1]	247
HomeServices [Member] | Subsidiary Debt [Member]
Debt Instrument [Line Items]
Par value		$ 247
HomeServices [Member] | Subsidiary Debt [Member] | Variable-rate Term Loan - Due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.819%	0.00%
HomeServices [Member] | HomeServices [Member] | Subsidiary Debt [Member] | Variable-rate Term Loan - Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt	[1]	$ 247	$ 0
[1]	(1)Amortizes quarterly.

Risk Management and Hedging 144

Risk Management and Hedging Activities - Balance Sheet Location (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		$ (17)	$ (77)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		76	74
Derivative Assets (Liabilities), at Fair Value, Net		59	(3)
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		40	48
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		40	48
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		102	94
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		102	94
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(60)	(60)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		18	13
Derivative Assets (Liabilities), at Fair Value, Net		(42)	(47)
Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(99)	(159)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		58	61
Derivative Assets (Liabilities), at Fair Value, Net		(41)	(98)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(24)	(66)
Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		39	47
Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		92	86
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(59)	(45)
Not Designated as Hedging Instrument [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(96)	(154)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		7	(11)
Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		1	1
Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		10	8
Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(1)	(15)
Designated as Hedging Instrument [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(3)	(5)
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	131	135
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(163)	(206)
Derivative, Fair Value, Net		(32)	(71)
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		119	148	$ 250	$ 223
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	29	42
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(6)	(10)
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	92	86
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	0	0
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	6	5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(64)	(46)
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	4	2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(93)	(150)
Commodity Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		16	6
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(17)	(22)
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		4	1
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	0
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		9	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(7)	0
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		2	2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	(14)
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	3
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(4)	(8)
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		16	15
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(8)	(10)
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		16	15
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(1)	(4)
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(7)	(6)
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		8	8
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	(3)
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		8	8
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	(3)
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		$ 0	$ 0
[1]	The Company's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of December 31, 2017 and 2016, a net regulatory asset of $119 million and $148 million, respectively, was recorded related to the net derivative liability of $32 million and $71 million, respectively. The difference between the net regulatory asset and the net derivative liability relates primarily to a power purchase agreement derivative at BHE Renewables.

Risk Management and Hedging 145

Risk Management and Hedging Activities - Not Designated as Hedging Contracts (Details) - Commodity Contract [Member] - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 148	$ 250	$ 223
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	53	(30)	128
Net Gains (Losses) Reclassified To Operating Revenue	10	(5)	1
Net losses reclassified to cost of sales	(92)	(67)	(102)
Ending balance	$ 119	$ 148	$ 250

Risk Management and Hedging 146

Risk Management and Hedging Activities - Designated as Hedging Contracts (Details) - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive (Income) Loss, Net, Derivatives [Roll Forward]
Cash flow hedge ineffectiveness	insignificant	Insignificant	Insignificant
Commodity Contract [Member]
Accumulated Other Comprehensive (Income) Loss, Net, Derivatives [Roll Forward]
Beginning balance	$ 16	$ 46	$ 32
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	15	26	52
Net gains reclassified to operating revenue	1	1	9
Net losses reclassified to cost of sales	(32)	(57)	(47)
Ending balance	$ 0	$ 16	$ 46

Risk Management and Hedging 147

Risk Management and Hedging Activities - Derivative Contract Volumes (Details) gal in Millions, MWh in Millions, Dth in Millions, $ in Millions	Dec. 31, 2017USD ($)galDthMWh	Dec. 31, 2016USD ($)galDthMWh
Commodity Contract [Member] | Electricity purchases (sales), net, in megawatt hours [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | MWh	4	5
Commodity Contract [Member] | Natural gas purchases, in decatherms [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | Dth	310	271
Commodity Contract [Member] | Fuel purchases (in gallons) [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | gal	0	11
Interest Rate Contract [Member] | Mortgage Sale Commitments, Net [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Notional Amount	$ (422)	$ (309)
United States of America, Dollars | Interest Rate Contract [Member] | Interest Rate Swap [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Notional Amount	(679)	(714)
United Kingdom, Pounds | Interest Rate Contract [Member] | Interest Rate Swap [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Notional Amount	$ (136)	$ 0

Risk Management and Hedging 148

Risk Management and Hedging Activities - Collateral and Contingent Features (Details) - Commodity Contract [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ (145)	$ (190)
Collateral Already Posted, Aggregate Fair Value	74	69
Additional Collateral, Aggregate Fair Value	$ 56	$ 110

Risk Management and Hedging 149

Risk Management and Hedging Activities - PacifiCorp - Balance Sheet Location (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		$ (17)	$ (77)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		76	74
Derivative Assets (Liabilities), at Fair Value, Net		59	(3)
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		40	48
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		40	48
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(60)	(60)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		18	13
Derivative Assets (Liabilities), at Fair Value, Net		(42)	(47)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(24)	(66)
Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		39	47
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(59)	(45)
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	131	135
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(163)	(206)
Derivative, Fair Value, Net		(32)	(71)
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		119	148	$ 250	$ 223
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	29	42
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(6)	(10)
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	6	5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(64)	(46)
PacifiCorp [Member] | Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(104)	(77)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		74	69
Derivative Assets (Liabilities), at Fair Value, Net		(30)	(8)
PacifiCorp [Member] | Commodity Contract [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		8	18
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		8	18
PacifiCorp [Member] | Commodity Contract [Member] | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		1	2
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		1	2
PacifiCorp [Member] | Commodity Contract [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(31)	(13)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		17	10
Derivative Assets (Liabilities), at Fair Value, Net		(14)	(3)
PacifiCorp [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(82)	(84)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		57	59
Derivative Assets (Liabilities), at Fair Value, Net		(25)	(25)
PacifiCorp [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		13	27
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(117)	(104)
Derivative, Fair Value, Net		(104)	(77)
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		101	73	$ 133	$ 85
PacifiCorp [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		11	24
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	(6)
Derivative, Fair Value, Net		8	18
PacifiCorp [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	2
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Derivative, Fair Value, Net		1	2
PacifiCorp [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	1
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(32)	(14)
Derivative, Fair Value, Net		(31)	(13)
PacifiCorp [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(82)	(84)
Derivative, Fair Value, Net		$ (82)	$ (84)
[1]	The Company's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of December 31, 2017 and 2016, a net regulatory asset of $119 million and $148 million, respectively, was recorded related to the net derivative liability of $32 million and $71 million, respectively. The difference between the net regulatory asset and the net derivative liability relates primarily to a power purchase agreement derivative at BHE Renewables.

Risk Management and Hedging 150

Risk Management and Hedging Activities - PacifiCorp - Not Designated as Hedging Contracts (Details) - Not Designated as Hedging Instrument [Member] - Commodity Contract [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 148	$ 250	$ 223
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	53	(30)	128
Net Gains (Losses) Reclassified To Operating Revenue	10	(5)	1
Ending balance	119	148	250
PacifiCorp [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	73	133	85
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	47	(27)	82
Net Gains (Losses) Reclassified To Operating Revenue	9	10	40
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	(28)	(43)	(74)
Ending balance	$ 101	$ 73	$ 133

Risk Management and Hedging 151

Risk Management and Hedging Activities - PacifiCorp - Derivative Contract Volumes (Details) - Commodity Contract [Member] gal in Millions, MWh in Millions, Dth in Millions	Dec. 31, 2017galDthMWh	Dec. 31, 2016galDthMWh
Electricity purchases (sales), net, in megawatt hours [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | MWh	(4)	(5)
Natural gas purchases, in decatherms [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | Dth	(310)	(271)
Fuel purchases (in gallons) [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | gal	0	(11)
PacifiCorp [Member] | Electricity purchases (sales), net, in megawatt hours [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | MWh	(9)	(3)
PacifiCorp [Member] | Natural gas purchases, in decatherms [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | Dth	(113)	(84)
PacifiCorp [Member] | Fuel purchases (in gallons) [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | gal	0	(11)

Risk Management and Hedging 152

Risk Management and Hedging Activities - PacifiCorp - Collateral and Contingent Features (Details) - Commodity Contract [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ (145)	$ (190)
Collateral Already Posted, Aggregate Fair Value	74	69
Additional Collateral, Aggregate Fair Value	56	110
PacifiCorp [Member]
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	110	97
Collateral Already Posted, Aggregate Fair Value	74	69
Additional Collateral, Aggregate Fair Value	$ 34	$ 22

Risk Management and Hedging 153

Risk Management and Hedging Activities - MEC - Balance Sheet Location (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		$ (17)	$ (77)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		76	74
Derivative Assets (Liabilities), at Fair Value, Net		59	(3)
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		40	48
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		40	48
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(60)	(60)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		18	13
Derivative Assets (Liabilities), at Fair Value, Net		(42)	(47)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(24)	(66)
Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		39	47
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(59)	(45)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		7	(11)
Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		1	1
Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(1)	(15)
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(32)	(71)
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		119	148	$ 250	$ 223
MidAmerican Energy Company [Member] | Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(3)	4
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	1
Derivative Assets (Liabilities), at Fair Value, Net		(3)	5
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		5	6
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		5	6
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		0	2
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		0	2
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(6)	(3)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	1
Derivative Assets (Liabilities), at Fair Value, Net		(6)	(2)
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net		(2)	(1)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	0
Derivative Assets (Liabilities), at Fair Value, Net		(2)	(1)
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	7	10
Derivative Liability, Fair Value, Gross Liability	[1]	(10)	(6)
Derivative, Fair Value, Net	[1]	(3)	4
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		3	(4)	$ 20	$ 38
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	6	8
Derivative Liability, Fair Value, Gross Liability	[1]	(1)	(2)
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	0	2
Derivative Liability, Fair Value, Gross Liability	[1]	0	0
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	1	0
Derivative Liability, Fair Value, Gross Liability	[1]	(7)	(3)
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	0	0
Derivative Liability, Fair Value, Gross Liability	[1]	$ (2)	$ (1)
[1]	(1)MidAmerican Energy's commodity derivatives not designated as hedging contracts are generally included in regulated rates. Accordingly, as of December 31, 2017, a net regulatory asset of $3 million was recorded related to the net derivative a liability of $3 million, and as of December 31, 2016, a net regulatory liability of $(4) million was recorded related to the net derivative asset of $4 million

Risk Management and Hedging 154

Risk Management and Hedging Activities Risk Management and Hedging Activities - MEC - Not Designated as Hedging Contracts (Details) - Commodity Contract [Member] - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 148	$ 250	$ 223
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	53	(30)	128
Net Gains (Losses) Reclassified To Operating Revenue	10	(5)	1
Ending balance	119	148	250
MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	(4)	20	38
Changes In Fair Value Derivatives Recognized In Regulatory Assets Or Liabilities, Net	16	3	40
Net Gains (Losses) Reclassified To Operating Revenue	1	(15)	(42)
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	(4)	0	(1)
Net Gains (Losses) Reclassified To Cost Of Natural Gas Purchases	(6)	(12)	(15)
Ending balance	3	(4)	20
Derivative, Gain (Loss) on Derivative, Net	0	0	(4)
Other Revenue Net [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	0	0	15
Cost Of Natural Gas [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	0	0	2
Cost Of Sales Nonregulated [Member] | MidAmerican Energy Company [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Derivative, Gain (Loss) on Derivative, Net	$ 0	$ 0	$ (21)

Risk Management and Hedging 155

Risk Management and Hedging Activities - MEC - Designated as Hedging Activities (Details) - Commodity Contract [Member] - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive (Income) Loss, Net, Derivatives [Roll Forward]
Beginning balance	$ 16	$ 46	$ 32
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(15)	(26)	(52)
Ending balance	0	16	46
MidAmerican Energy Company [Member]
Accumulated Other Comprehensive (Income) Loss, Net, Derivatives [Roll Forward]
Beginning balance	0	45	34
Cumulative Net Gain (Loss) From Cash Flow Hedges, Before Taxes Transferred to Affiliate	0	(45)	0
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	0	0	58
Cash Flow Hedge Gain (Loss) Reclassified To Cost Of Sales Nonregulated	0	0	(47)
Ending balance	$ 0	$ 0	$ 45

Risk Management and Hedging 156

Risk Management and Hedging Activities - MEC - Derivative Contract Volumes (Details) - Commodity Contract [Member] MWh in Millions, Dth in Millions	Dec. 31, 2017DthMWh	Dec. 31, 2016DthMWh
Electricity purchases (sales), net, in megawatt hours [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | MWh	4	5
Natural gas purchases, in decatherms [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount	310	271
Natural gas purchases, in decatherms [Member] | MidAmerican Energy Company [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount	21	18

Risk Management and Hedging 157

Risk Management and Hedging Activities - MEC - Collateral and Contingent Features (Details) - Commodity Contract [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ (145)	$ (190)
Additional Collateral, Aggregate Fair Value	56	110
Collateral Already Posted, Aggregate Fair Value	74	69
MidAmerican Energy Company [Member]
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	8	3
Additional Collateral, Aggregate Fair Value	0	2
Collateral Already Posted, Aggregate Fair Value	$ 0	$ 0

Risk Management and Hedging 158

Risk Management and Hedging Activities Risk Management and Hedging Activities - NPC - Balance Sheet Location (Details) - Commodity Contract [Member] - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	$ 163	$ 206
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		119	148	$ 250	$ 223
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	64	46
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		10	27
Nevada Power Company [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[2]	2	7
Nevada Power Company [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[2]	1	7
Nevada Power Company [Member] | Fair Value, Measurements, Recurring [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		3	14
Nevada Power Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		3	14
Net Regulatory Asset (Liability), Unrealized Loss (Gain) On Derivative Contracts		$ (3)	$ (14)
[1]	The Company's commodity derivatives not designated as hedging contracts are generally included in regulated rates, and as of December 31, 2017 and 2016, a net regulatory asset of $119 million and $148 million, respectively, was recorded related to the net derivative liability of $32 million and $71 million, respectively. The difference between the net regulatory asset and the net derivative liability relates primarily to a power purchase agreement derivative at BHE Renewables.
[2]	Nevada Power's commodity derivatives not designated as hedging contracts are included in regulated rates and as of December 31, 2017 and 2016, a regulatory asset of $3 million and $14 million, respectively, was recorded related to the derivative liability of $3 million and $14 million, respectively.

Risk Management and Hedging 159

Risk Management and Hedging Activities Risk Management and Hedging Activities - NPC - Derivative Contract Volumes (Details) - Commodity Contract [Member] MWh in Millions, Dth in Millions	Dec. 31, 2017DthMWh	Dec. 31, 2016DthMWh
Electricity purchases (sales), net, in megawatt hours [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | MWh	(4)	(5)
Natural gas purchases, in decatherms [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | Dth	(310)	(271)
Nevada Power Company [Member] | Electricity purchases (sales), net, in megawatt hours [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | MWh	0	(2)
Nevada Power Company [Member] | Natural gas purchases, in decatherms [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | Dth	(125)	(114)

Risk Management and Hedging 160

Risk Management and Hedging Activities Risk Management and Hedging Activities - NPC - Collateral and Contingent Features (Details) - Commodity Contract [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ (145)	$ (190)
Nevada Power Company [Member]
Derivative [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ 1	$ 2

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash collateral receivable (payable), offset against derivative positions		$ 76	$ 74
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	(29)	(22)
Assets, Fair Value Disclosure		3,945	2,878
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	105	96
Derivative Liability		(83)	(145)
Cash collateral receivable (payable), offset against derivative positions	[1]	76	74
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		3,296	2,339
Derivative Liability		(3)	(3)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		565	467
Derivative Liability		(175)	(210)
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		113	94
Derivative Liability		(10)	(28)
Mortgage loans held for sale [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		465	359
Mortgage loans held for sale [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Mortgage loans held for sale [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		465	359
Mortgage loans held for sale [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	685	586
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	685	586
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	0	0
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	0	0
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		176	161
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		176	161
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
United States government obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
International governement obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		5	3
International governement obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
International governement obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		5	3
International governement obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		36	36
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		36	36
Corporate obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	2
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	2
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			2
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			0
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			2
Agency, asset and mortgage-backed obligations [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			0
United States companies [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		288	250
United States companies [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		288	250
United States companies [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
United States companies [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
International companies [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		1,968	1,190
International companies [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		1,968	1,190
International companies [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
International companies [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Investment funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	(29)	(22)
Derivative assets		118	119
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	105	96
Derivative Liability		(75)	(132)
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		3	2
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		42	49
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		167	199
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		104	87
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		10	27
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		24	23
Derivative Liability		(8)	(13)
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	1
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		15	16
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		8	11
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		9	7
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		$ 0	$ 1
[1]	Represents netting under master netting arrangements and a net cash collateral receivable of $76 million and $74 million as of December 31, 2017 and 2016, respectively.
[2]	Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.

Fair Value Measurements - Level

Fair Value Measurements - Level 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commodity [Member]
Fair Value, Assets (Liabilities), Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 60	$ 47	$ 51
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings	23	8	19
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)	(3)	(2)	(7)
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net	(1)	(11)	(19)
Purchases	1	1	1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0	0	0
Settlements	14	17	2
Transfers from level 2	0	0	0
Ending balance	94	60	47
Interest Rate Lock Commitments [Member]
Fair Value, Assets (Liabilities), Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	6	4	0
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings	147	121	87
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net	0	0	0
Purchases	4	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0	0	0
Settlements	(148)	(119)	(86)
Transfers from level 2	0	0	3
Ending balance	9	6	4
Auction Rate Securities [Member]
Fair Value, Assets (Liabilities), Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	44	45
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings	0	5	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	8	(1)
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net	0	0	0
Purchases	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0	(57)	0
Settlements	0	0	0
Transfers from level 2	0	0	0
Ending balance	$ 0	$ 0	$ 44

Fair Value Measurements - Debt

Fair Value Measurements - Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 35,193	$ 36,116
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 40,522	$ 40,718

Fair Value Measurements - Pacif

Fair Value Measurements - PacifiCorp (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		$ 76	$ 74
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	(29)	(22)
Assets, Fair Value Disclosure		3,945	2,878
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	105	96
Derivative Liability		(83)	(145)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions	[1]	76	74
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		3,296	2,339
Derivative Liability		(3)	(3)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		565	467
Derivative Liability		(175)	(210)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		113	94
Derivative Liability		(10)	(28)
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	(29)	(22)
Derivative assets		118	119
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	105	96
Derivative Liability		(75)	(132)
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	(2)
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		42	49
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(167)	(199)
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		104	87
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(10)	(27)
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	685	586
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	685	586
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	0	0
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]	0	0
Investment funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
PacifiCorp [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		51	50
PacifiCorp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		42	30
PacifiCorp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		13	27
PacifiCorp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		0	0
PacifiCorp [Member] | Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		74	69
PacifiCorp [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[3]	(4)	(7)
Derivative assets		9	20
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[3]	78	76
Derivative Liability		(39)	(28)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		74	69
PacifiCorp [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
PacifiCorp [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		13	27
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(117)	(104)
PacifiCorp [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
PacifiCorp [Member] | Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	21	13
PacifiCorp [Member] | Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	21	13
PacifiCorp [Member] | Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	0	0
PacifiCorp [Member] | Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	0	0
PacifiCorp [Member] | Investment funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment funds		21	17	[4]
PacifiCorp [Member] | Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment funds		21	17	[4]
PacifiCorp [Member] | Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment funds		0	0	[4]
PacifiCorp [Member] | Investment funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment funds		$ 0	$ 0	[4]
[1]	Represents netting under master netting arrangements and a net cash collateral receivable of $76 million and $74 million as of December 31, 2017 and 2016, respectively.
[2]	Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
[3]	Represents netting under master netting arrangements and a net cash collateral receivable of $74 million and $69 million as of December 31, 2017 and 2016, respectively.
[4]	Amounts are included in cash and cash equivalents, other current assets and other assets on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.

Fair Value Measurements - Pa165

Fair Value Measurements - PacifiCorp - Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 35,193	$ 36,116
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	40,522	40,718
PacifiCorp [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	7,005	7,052
PacifiCorp [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 8,370	$ 8,204

Fair Value Measurements - MEC (

Fair Value Measurements - MEC (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		$ 76	$ 74
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		3,945	2,878
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	(29)	(22)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	105	96
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions	[1]	76	74
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		3,296	2,339
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		565	467
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		113	94
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[1]	(29)	(22)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1]	105	96
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		1	5
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	(2)
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		42	49
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(167)	(199)
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		104	87
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(10)	(27)
MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		667	477
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[2]	(2)	(2)
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	1
MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		619	426
MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		46	52
MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		4	1
MidAmerican Energy Company [Member] | Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Collateral, Net Receivable (Payable), Offset Against Derivative Positions		0	1
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		5	8
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	[2]	(2)	(2)
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(8)	(3)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[2]	2	3
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		0	0
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		3	9
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(9)	(3)
MidAmerican Energy Company [Member] | Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		4	1
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(1)	(3)
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[3]	685	586
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[3]	685	586
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[3]	0	0
Money market mutual funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[3]	0	0
Money market mutual funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	133	1
Money market mutual funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	133	1
Money market mutual funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	0	0
Money market mutual funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[4]	0	0
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		176	161
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		176	161
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
US Treasury Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		176	161
US Treasury Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		176	161
US Treasury Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
US Treasury Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Government Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		5	3
Foreign Government Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Government Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		5	3
Foreign Government Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Government Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		5	3
Foreign Government Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Government Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		5	3
Foreign Government Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		36	36
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		36	36
Domestic Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Domestic Corporate Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		36	36
Domestic Corporate Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Domestic Corporate Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		36	36
Domestic Corporate Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	2
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	2
Municipal Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Municipal Bonds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	2
Municipal Bonds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Municipal Bonds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	2
Municipal Bonds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			2
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			2
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			0
US Government-sponsored Enterprises Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			2
US Government-sponsored Enterprises Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			0
US Government-sponsored Enterprises Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			2
US Government-sponsored Enterprises Debt Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities			0
Domestic Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		288	250
Domestic Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		288	250
Domestic Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Domestic Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Domestic Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		288	250
Domestic Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		288	250
Domestic Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Domestic Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		1,968	1,190
Foreign Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		1,968	1,190
Foreign Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Equity Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		7	5
Foreign Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		7	5
Foreign Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Foreign Equity Securities [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Equity Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Equity Funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Equity Funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Equity Funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Equity Funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		15	9
Equity Funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		15	9
Equity Funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Equity Funds [Member] | MidAmerican Energy Company [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		$ 0	$ 0
[1]	Represents netting under master netting arrangements and a net cash collateral receivable of $76 million and $74 million as of December 31, 2017 and 2016, respectively.
[2]	(1)Represents netting under master netting arrangements and a net cash collateral receivable of $- million and $1 million as of December 31, 2017 and 2016, respectively.
[3]	Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
[4]	(2)Amounts are included in cash and cash equivalents and investments and restricted cash and investments on the Balance Sheets. The fair value of these money market mutual funds approximates cost.

Fair Value Measurements - MEC -

Fair Value Measurements - MEC - Level 3 (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Auction Rate Securities [Member]
Fair Value, Assets (Liabilities), Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance		$ 0	$ 44	$ 45
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings		0	5	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)		0	8	(1)
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net		0	0	0
Purchases		0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		0	57	0
Settlements		0	0	0
Ending balance		0	0	44
MidAmerican Energy Company [Member] | Derivative [Member]
Fair Value, Assets (Liabilities), Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance		(2)	(6)	12
Fair Value, Measurements With Unobservable Inputs Reconciliation, Recurring Basis, Transferred To Affiliate		0	(4)	0
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings	[1]	0	0	11
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)		0	0	(7)
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net		2	(6)	(25)
Purchases		0	0	1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		0	0	0
Settlements		3	14	2
Ending balance		3	(2)	(6)
Unrealized Gain (Loss) on Derivatives and Commodity Contracts				8
MidAmerican Energy Company [Member] | Auction Rate Securities [Member]
Fair Value, Assets (Liabilities), Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance		0	26	26
Fair Value, Measurements With Unobservable Inputs Reconciliation, Recurring Basis, Transferred To Affiliate		0	0	0
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings		0	5	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)		0	4	0
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net		0	0	0
Purchases		0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		0	35	0
Settlements		0	0	0
Ending balance		$ 0	$ 0	$ 26
[1]	(1)Changes included in earnings related to MidAmerican Energy's unregulated retail services business that was transferred to an affiliate of BHE. Refer to Note 3 for a discussion of discontinued operations. Net unrealized gains included in earnings for the year ended December 31, 2015, related to commodity derivatives held at December 31, 2015, totaled $8 million.

Fair Value Measurements - ME168

Fair Value Measurements - MEC - Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 35,193	$ 36,116
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	40,522	40,718
MidAmerican Energy Company [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	5,042	4,301
Long-term Debt, Fair Value		$ 4,735
MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 5,686

Fair Value Measurements - MidAm

Fair Value Measurements - MidAmerican Funding - Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 35,193	$ 36,116
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	40,522	40,718
MidAmerican Funding, LLC and Subsidiaries [Domain]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	5,282	4,627
Long-term Debt, Fair Value		$ 5,164
MidAmerican Funding, LLC and Subsidiaries [Domain] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 6,006

Fair Value Measurements - NPC (

Fair Value Measurements - NPC (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 3,945	$ 2,878
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		3,296	2,339
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		565	467
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		113	94
Commodity Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	(2)
Commodity Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(167)	(199)
Commodity Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(10)	(27)
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	685	586
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	685	586
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	0	0
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	0	0
Equity Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Nevada Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			226
Nevada Power Company [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			226
Nevada Power Company [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			0
Nevada Power Company [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			0
Nevada Power Company [Member] | Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	(14)
Nevada Power Company [Member] | Commodity Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Nevada Power Company [Member] | Commodity Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		0	0
Nevada Power Company [Member] | Commodity Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		(3)	(14)
Nevada Power Company [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		220
Nevada Power Company [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		220
Nevada Power Company [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		0
Nevada Power Company [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		0
Nevada Power Company [Member] | Equity Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	6
Nevada Power Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		2	6
Nevada Power Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Nevada Power Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		$ 0	$ 0
[1]	Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
[2]	Amounts are included in cash and cash equivalents on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.

Fair Value Measurements - NPC -

Fair Value Measurements - NPC - Level 3 (Details) - Commodity [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability), Net, Value	$ 94	$ 60	$ 47	$ 51
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net	(1)	(11)	(19)
Purchases	1	1	1
Settlements	14	17	2
Ending balance	94	60	47
Nevada Power Company [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset (Liability), Net, Value	(3)	(14)	(22)	$ (30)
Fair Value, Measurements with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included In Regulatory Assets and Liabilities, Net	(3)	(4)	0
Settlements	14	12	8
Ending balance	$ (3)	$ (14)	$ (22)

Fair Value Measurements - NP172

Fair Value Measurements - NPC - Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 35,193	$ 36,116
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	40,522	40,718
Nevada Power Company [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	2,600	2,581
Nevada Power Company [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 3,088	$ 3,040

Fair Value Measurements - SPPC

Fair Value Measurements - SPPC (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 3,945	$ 2,878
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		3,296	2,339
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		565	467
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		113	94
Equity Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		178	147
Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	685	586
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	685	586
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	0	0
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[1]	0	0
Sierra Pacific Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			36
Sierra Pacific Power Company [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			36
Sierra Pacific Power Company [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			0
Sierra Pacific Power Company [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			0
Sierra Pacific Power Company [Member] | Equity Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	1
Sierra Pacific Power Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	1
Sierra Pacific Power Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		0	0
Sierra Pacific Power Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		$ 0	0
Sierra Pacific Power Company [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		35
Sierra Pacific Power Company [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		35
Sierra Pacific Power Company [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		0
Sierra Pacific Power Company [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	[2]		$ 0
[1]	Amounts are included in cash and cash equivalents; other current assets; and noncurrent investments and restricted cash and investments on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.
[2]	Amounts are included in cash and cash equivalents on the Consolidated Balance Sheets. The fair value of these money market mutual funds approximates cost.

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements - SPPC - Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	$ 35,193	$ 36,116
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	40,522	40,718
Sierra Pacific Power Company [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt	1,120	1,119
Sierra Pacific Power Company [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 1,221	$ 1,191

Other, Net - MEC (Details)

Other, Net - MEC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ (398)	$ 36	$ 39
MidAmerican Energy Company [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	19	14	5
MidAmerican Energy Company [Member] | Corporate Owned Life Insurance Income (Loss) [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	13	8	4
MidAmerican Energy Company [Member] | Available-For-Sale Securities, Gross Gain (Loss) [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	0	5	0
MidAmerican Energy Company [Member] | Other Income (Expense) [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ 6	$ 1	$ 1

Other, Net - MidAmerican Fundin

Other, Net - MidAmerican Funding (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Component of Other Income (Expense), Nonoperating [Line Items]
Other Nonrecurring (Income) Expense	$ 455	$ 62	$ (8)
Other, net	(398)	36	39
MidAmerican Funding, LLC and Subsidiaries [Domain]
Component of Other Income (Expense), Nonoperating [Line Items]
Other Nonrecurring (Income) Expense	29	0	0
Other, net	(9)	19	19
MidAmerican Funding, LLC and Subsidiaries [Domain] | Corporate Owned Life Insurance Income (Loss) [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	13	8	4
MidAmerican Funding, LLC and Subsidiaries [Domain] | Available-For-Sale Securities, Gross Gain (Loss) [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	0	5	0
MidAmerican Funding, LLC and Subsidiaries [Domain] | Gains (Losses) on Disposition of Assets [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other Nonrecurring (Income) Expense			13
Other, net	1	3	13
MidAmerican Funding, LLC and Subsidiaries [Domain] | Gain (Loss) on Extinguishment of Debt [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	(29)	0	0
MidAmerican Funding, LLC and Subsidiaries [Domain] | Other Income (Expense) [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ 6	$ 3	$ 2

Income Taxes Income Taxes - Tax

Income Taxes Income Taxes - Tax Reform (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate			35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net			$ 8,242	$ 13,879
Regulatory Liabilities			7,511	3,120
Deferred Income Tax Expense (Benefit)			26	1,098	$ 1,274
Net income (loss) attributable to parent			2,870	2,542	2,370
Income tax (benefit) expense			(554)	403	450
Equity income (loss)			(151)	123	$ 115
Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[1]		$ 4,143	$ 25
Tax Cuts and Jobs Act of 2017 [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate			21.00%
Deferred Tax Liabilities, Net	[2]		$ 7,115
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]		5,950
Deferred Income Tax Expense (Benefit)	[2]	$ 1,150
Net income (loss) attributable to parent	[2]		$ 516
Income tax (benefit) expense	[2]	1,150
Foreign Earnings Repatriated		419
Equity income (loss)		$ 228
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)	$ (653)	$ (743)	$ (929)
Current State and Local Tax Expense (Benefit)	(3)	1	29
Current foreign	83	55	84
Current Income Tax Expense (Benefit)	(573)	(687)	(816)
Deferred Federal Income Tax Expense (Benefit)	(76)	1,164	1,310
Deferred State and Local Income Tax Expense (Benefit)	100	(59)	(53)
Deferred foreign	2	(7)	17
Deferred Income Tax Expense (Benefit)	26	1,098	1,274
Other Tax Expense (Benefit)	(7)	(8)	(8)
Total income tax expense (benefit)	$ (554)	$ 403	$ 450

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Nov. 30, 2015	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal statutory income tax rate			35.00%	35.00%	35.00%
Income tax credits			(20.00%)	(14.00%)	(11.00%)
State income tax, net of federal income tax benefit			3.00%	(1.00%)	(1.00%)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent			(31.00%)	(0.00%)	(0.00%)
Income tax effect of foreign income			(5.00%)	(6.00%)	(7.00%)
Equity income			2.00%	(2.00%)	(2.00%)
Other, net			(2.00%)	(2.00%)	(2.00%)
Effective income tax rate			(22.00%)	14.00%	16.00%
Production Tax Credit Carryforwards [Abstract]
Years Eligible For Renewable Energy Production Tax Credit			10 years
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred state			$ (100)	$ 59	$ 53
Related Party Tax Expense [Abstract]
Income Taxes Receivable From (Payable To) Related Parties Current			(334)	27
UNITED KINGDOM
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount			$ 16	$ 39
Corporate Income Tax Rate, Effective April 1, 2020 [Member] | UNITED KINGDOM
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(18.00%)	0.00%
Corporate Income Tax Rate, Effective April 1, 2020 further reduction [Member] | UNITED KINGDOM
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		(17.00%)
Corporate Income Tax Rate Enacted November 2015, Effective April 1, 2017 [Member] | UNITED KINGDOM
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(20.00%)
Corporate Income Tax Rate Enacted November 2015, Effective April 1, 2017 19% [Member] | UNITED KINGDOM
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(19.00%)

Income Taxes - Components of Ne

Income Taxes - Components of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets: [Abstract]
Federal, state and foreign carryforwards	$ 1,118	$ 987
Regulatory liabilities	1,707	909
AROs	223	326
Employee benefits	45	209
Derivative contracts	2	29
Other	448	707
Total deferred income tax assets	3,543	3,167
Valuation allowances	(126)	(64)
Total deferred income tax assets, net	3,417	3,103
Deferred income tax liabilities: [ Abstract]
Property-related items	(9,950)	(14,237)
Regulatory assets	(651)	(1,449)
Investments	(843)	(962)
Other	(215)	(334)
Total deferred income tax liabilities	(11,659)	(16,982)
Net deferred income tax liability	$ (8,242)	$ (13,879)

Income Taxes - Summary of Opera

Income Taxes - Summary of Operating Loss Carryforwards (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 172	[1]
Deferred Tax Assets, Operating Loss Carryforwards	37
Deferred Tax Assets, Tax Credit Carryforwards	31
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	10,813	[1]
Deferred Tax Assets, Operating Loss Carryforwards	858
Deferred Tax Assets, Tax Credit Carryforwards	29
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	605	[1]
Deferred Tax Assets, Operating Loss Carryforwards	163
Deferred Tax Assets, Tax Credit Carryforwards	0
Income Tax Authority, Name [Domain]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	11,590	[1]
Deferred Tax Assets, Operating Loss Carryforwards	1,058
Deferred Tax Assets, Tax Credit Carryforwards	$ 60
Minimum [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2023
Tax Credit Carryforward, Expiration Date	Dec. 31, 2023
Minimum [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2017
Tax Credit Carryforward, Expiration Date	Dec. 31, 2016
Maximum [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2025
Maximum [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2036
[1]	The federal net operating loss carryforwards relate principally to net operating loss carryforwards of subsidiaries that are tax residents in both the United States and the United Kingdom. The federal net operating loss carryforwards were generated prior to Berkshire Hathaway Inc.'s ownership and will begin to expire in 2023.

Income Taxes - Net Unrecognized

Income Taxes - Net Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 128	$ 198
Additions based on tax positions related to the current year	6	7
Additions for tax positions of prior years	70	6
Reductions for tax positions of prior years	(18)	(11)
Statute of limitations	(4)	(1)
Settlements	(1)	(67)
Interest and penalties	0	(4)
Ending balance	181	128
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	158	104
Unrecognized tax benefits that would not impact the effective tax rate	$ 23	$ 24

Income Taxes Income Taxes - Pac

Income Taxes Income Taxes - PacifiCorp - Tax Reform (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 8,242	$ 13,879
Regulatory Liabilities		$ 7,511	$ 3,120
PacifiCorp [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 2,582	$ 4,880
Regulatory Liabilities		3,071	1,032
Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[1]	4,143	25
Deferred Income Tax Charge [Member] | PacifiCorp [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities		$ 1,960	$ 9
Tax Cuts and Jobs Act of 2017 [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 7,115
Tax Cuts and Jobs Act of 2017 [Member] | PacifiCorp [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net		$ 2,361
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	5,950
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member] | PacifiCorp [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities		$ 2,358
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Income Taxes - PacifiCorp - Com

Income Taxes - PacifiCorp - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Income Tax Expense (Benefit) Components [Line Items]
Current Federal Tax Expense (Benefit)	$ (653)	$ (743)	$ (929)
Current State and Local Tax Expense (Benefit)	(3)	1	29
Current Income Tax Expense (Benefit)	(573)	(687)	(816)
Deferred Federal Income Tax Expense (Benefit)	(76)	1,164	1,310
Deferred State and Local Income Tax Expense (Benefit)	100	(59)	(53)
Deferred Income Tax Expense (Benefit)	26	1,098	1,274
Other Tax Expense (Benefit)	(7)	(8)	(8)
Income tax (benefit) expense	(554)	403	450
PacifiCorp [Member]
Schedule of Income Tax Expense (Benefit) Components [Line Items]
Current Federal Tax Expense (Benefit)	249	169	130
Current State and Local Tax Expense (Benefit)	41	32	26
Current Income Tax Expense (Benefit)	290	201	156
Deferred Federal Income Tax Expense (Benefit)	59	123	148
Deferred State and Local Income Tax Expense (Benefit)	15	21	29
Deferred Income Tax Expense (Benefit)	74	144	177
Other Tax Expense (Benefit)	(4)	(5)	(5)
Income tax (benefit) expense	$ 360	$ 340	$ 328

Income Taxes - PacifiCorp - Rec

Income Taxes - PacifiCorp - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	(3.00%)	1.00%	1.00%
Income tax credits	(20.00%)	(14.00%)	(11.00%)
Other, net	(2.00%)	(2.00%)	(2.00%)
Effective income tax rate	(22.00%)	14.00%	16.00%
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Years Eligible For Renewable Energy Production Tax Credit	10 years
PacifiCorp [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	3.00%	3.00%	3.00%
Income tax credits	(5.00%)	(6.00%)	(6.00%)
Other, net	(1.00%)	(1.00%)	0.00%
Effective income tax rate	32.00%	31.00%	32.00%
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Years Eligible For Renewable Energy Production Tax Credit	10 years

Income Taxes - PacifiCorp - 186

Income Taxes - PacifiCorp - Component of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	$ 1,707	$ 909
AROs	223	326
Other	448	707
Total deferred income tax assets, net	3,417	3,103
Property-related items	(9,950)	(14,237)
Regulatory assets	(651)	(1,449)
Other	(215)	(334)
Total deferred income tax liabilities	(11,659)	(16,982)
Net deferred income tax liability	(8,242)	(13,879)
PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	756	393
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	84	202
Deferred Tax Assets, Derivative Instruments And Unamortized Contract Values	48	67
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards, State and Local	83	69
AROs	50	78
Other	50	94
Total deferred income tax assets, net	1,071	903
Property-related items	(3,381)	(5,161)
Regulatory assets	(261)	(586)
Other	(11)	(36)
Total deferred income tax liabilities	(3,653)	(5,783)
Net deferred income tax liability	$ (2,582)	$ (4,880)

Income Taxes - PacifiCorp - Sum

Income Taxes - PacifiCorp - Summary of Operating Loss Carryforwards (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 10,813	[1]
Deferred Tax Assets, Operating Loss Carryforwards	858
Deferred Tax Assets, Tax Credit Carryforwards	29
PacifiCorp [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	1,356
Deferred Tax Assets, Operating Loss Carryforwards	63
Deferred Tax Assets, Tax Credit Carryforwards	$ 20
Minimum [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2017
Tax Credit Carryforward, Expiration Date	Dec. 31, 2016
Minimum [Member] | PacifiCorp [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2018
Minimum [Member] | PacifiCorp [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2018
Maximum [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2036
Maximum [Member] | PacifiCorp [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2032
[1]	The federal net operating loss carryforwards relate principally to net operating loss carryforwards of subsidiaries that are tax residents in both the United States and the United Kingdom. The federal net operating loss carryforwards were generated prior to Berkshire Hathaway Inc.'s ownership and will begin to expire in 2023.

Income Taxes Income Taxes - 188

Income Taxes Income Taxes - PacifiCorp - Net Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 181	$ 128	$ 198
PacifiCorp [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 10	$ 12

Income Taxes Income Taxes - MEC

Income Taxes Income Taxes - MEC - Tax Reform (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 8,242	$ 13,879
Regulatory Liabilities		$ 7,511	$ 3,120
MidAmerican Energy Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 2,237	$ 3,572
Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[1]	$ 4,143	$ 25
Tax Cuts and Jobs Act of 2017 [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 7,115
Tax Cuts and Jobs Act of 2017 [Member] | MidAmerican Energy Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 1,824
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	5,950
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member] | MidAmerican Energy Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	$ 1,845
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Income Taxes Income Taxes - 190

Income Taxes Income Taxes - MEC - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	$ (653)	$ (743)	$ (929)
Current State and Local Tax Expense (Benefit)	(3)	1	29
Current Income Tax Expense (Benefit)	(573)	(687)	(816)
Deferred Federal Income Tax Expense (Benefit)	(76)	1,164	1,310
Deferred State and Local Income Tax Expense (Benefit)	100	(59)	(53)
Deferred Income Tax Expense (Benefit)	26	1,098	1,274
Other Tax Expense (Benefit)	(7)	(8)	(8)
Income tax (benefit) expense	(554)	403	450
MidAmerican Energy Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	(490)	(479)	(415)
Current State and Local Tax Expense (Benefit)	(25)	(14)	(6)
Current Income Tax Expense (Benefit)	(515)	(493)	(421)
Deferred Federal Income Tax Expense (Benefit)	335	366	281
Deferred State and Local Income Tax Expense (Benefit)	(2)	(4)	(6)
Deferred Income Tax Expense (Benefit)	333	362	275
Other Tax Expense (Benefit)	(1)	(1)	(1)
Income tax (benefit) expense	$ (183)	$ (132)	$ (147)

Income Taxes Income Taxes - 191

Income Taxes Income Taxes - MEC - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Tax Credit, Percent	(20.00%)	(14.00%)	(11.00%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	(3.00%)	1.00%	1.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(31.00%)	(0.00%)	(0.00%)
Other, net	(2.00%)	(2.00%)	(2.00%)
Effective income tax rate	(22.00%)	14.00%	16.00%
Years Eligible For Renewable Energy Production Tax Credit	10 years
MidAmerican Energy Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Tax Credit, Percent	(68.00%)	(61.00%)	(71.00%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	(4.00%)	(3.00%)	(2.00%)
Effective Income Tax Rate Reconciliation Regulatory Differences	(7.00%)	(3.00%)	(12.00%)
Other, net	(1.00%)	0.00%	1.00%
Effective income tax rate	(43.00%)	(32.00%)	(49.00%)
Years Eligible For Renewable Energy Production Tax Credit	10 years
Tax Cuts and Jobs Act of 2017 [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	21.00%
Tax Cuts and Jobs Act of 2017 [Member] | MidAmerican Energy Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	21.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	2.00%	(0.00%)	(0.00%)

Income Taxes - MEC - Components

Income Taxes - MEC - Components of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	$ 1,707	$ 909
Derivative contracts	2	29
AROs	223	326
Other	448	707
Total deferred income tax assets, net	3,417	3,103
Property-related items	(9,950)	(14,237)
Regulatory assets	(651)	(1,449)
Other	(215)	(334)
Total deferred income tax liabilities	(11,659)	(16,982)
Net deferred income tax liability	(8,242)	(13,879)
MidAmerican Energy Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	443	333
AROs	45	66
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	160	230
Other	57	74
Total deferred income tax assets, net	705	703
Property-related items	(2,865)	(3,763)
Regulatory assets	(42)	(471)
Other	(35)	(41)
Total deferred income tax liabilities	(2,942)	(4,275)
Net deferred income tax liability	$ (2,237)	$ (3,572)

Income Taxes - MEC - Summary of

Income Taxes - MEC - Summary of Operating Loss Carryforwards (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Federal, state and foreign carryforwards		$ 1,118	$ 987
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	[1]	10,813
MidAmerican Energy Company [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Federal, state and foreign carryforwards		40
Operating Loss Carryforwards		$ 583
MidAmerican Energy Company [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate		2,018
MidAmerican Energy Company [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate		2,036
[1]	The federal net operating loss carryforwards relate principally to net operating loss carryforwards of subsidiaries that are tax residents in both the United States and the United Kingdom. The federal net operating loss carryforwards were generated prior to Berkshire Hathaway Inc.'s ownership and will begin to expire in 2023.

Income Taxes - MEC - Net Unreco

Income Taxes - MEC - Net Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 128	$ 198
Additions based on tax positions related to the current year	6	7
Additions for tax positions of prior years	70	6
Reductions for tax positions of prior years	(18)	(11)
Statute of limitations	(4)	(1)
Settlements	(1)	(67)
Interest and penalties	0	(4)
Ending balance	181	128
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	158	104
MidAmerican Energy Company [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	10	10
Additions based on tax positions related to the current year	1	0
Additions for tax positions of prior years	23	10
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	(4)	(2)
Reductions for tax positions of prior years	(19)	(8)
Interest and penalties	1	0
Ending balance	12	$ 10
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 38

Income Taxes Income Taxes - Mid

Income Taxes Income Taxes - MidAmerican Funding - Tax Reform (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 8,242	$ 13,879
Regulatory Liabilities		7,511	3,120
Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[1]	$ 4,143	$ 25
MidAmerican Funding, LLC and Subsidiaries [Domain]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 2,235	$ 3,568
Tax Cuts and Jobs Act of 2017 [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 7,115
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	$ 5,950
Tax Cuts and Jobs Act of 2017 [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 1,822
Tax Cuts and Jobs Act of 2017 [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	$ 1,845
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Income Taxes - MidAmerican Fund

Income Taxes - MidAmerican Funding - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	$ (653)	$ (743)	$ (929)
Current State and Local Tax Expense (Benefit)	(3)	1	29
Current Income Tax Expense (Benefit)	(573)	(687)	(816)
Deferred Federal Income Tax Expense (Benefit)	(76)	1,164	1,310
Deferred State and Local Income Tax Expense (Benefit)	100	(59)	(53)
Deferred Income Tax Expense (Benefit)	26	1,098	1,274
Other Tax Expense (Benefit)	(7)	(8)	(8)
Income tax (benefit) expense	(554)	403	450
MidAmerican Funding, LLC and Subsidiaries [Domain]
Components of Income Tax Expense (Benefit) [Line Items]
Current Federal Tax Expense (Benefit)	(505)	(485)	(418)
Current State and Local Tax Expense (Benefit)	(31)	(16)	(8)
Current Income Tax Expense (Benefit)	(536)	(501)	(426)
Deferred Federal Income Tax Expense (Benefit)	338	367	282
Deferred State and Local Income Tax Expense (Benefit)	(3)	(4)	(5)
Deferred Income Tax Expense (Benefit)	335	363	277
Other Tax Expense (Benefit)	(1)	(1)	(1)
Income tax (benefit) expense	$ (202)	$ (139)	$ (150)

Income Taxes Income Taxes - 197

Income Taxes Income Taxes - MidAmerican Funding - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Income tax credits	(20.00%)	(14.00%)	(11.00%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	(3.00%)	1.00%	1.00%
Other, net	(2.00%)	(2.00%)	(2.00%)
Effective income tax rate	(22.00%)	14.00%	16.00%
Years Eligible For Renewable Energy Production Tax Credit	10 years
MidAmerican Funding, LLC and Subsidiaries [Domain]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Income tax credits	(77.00%)	(64.00%)	(72.00%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	(6.00%)	(3.00%)	(3.00%)
Effective Income Tax Rate Reconciliation Regulatory Differences	(8.00%)	(3.00%)	(12.00%)
Other, net	(1.00%)	0.00%	1.00%
Effective income tax rate	(54.00%)	(35.00%)	(51.00%)
Years Eligible For Renewable Energy Production Tax Credit	10 years

Income Taxes Income Taxes - 198

Income Taxes Income Taxes - MidAmerican Funding - Components of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities		$ 1,707	$ 909
Derivative contracts		2	29
AROs		223	326
Other		448	707
Total deferred income tax assets, net		3,417	3,103
Property-related items		(9,950)	(14,237)
Regulatory assets		(651)	(1,449)
Other		(215)	(334)
Total deferred income tax liabilities		(11,659)	(16,982)
Net deferred income tax liability		(8,242)	(13,879)
Federal, state and foreign carryforwards		1,118	987
MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities		443	333
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits		45	66
AROs		160	230
Other		62	82
Total deferred income tax assets, net		710	711
Property-related items		(2,868)	(3,767)
Regulatory assets		(42)	(471)
Other		(35)	(41)
Total deferred income tax liabilities		(2,945)	(4,279)
Net deferred income tax liability		(2,235)	$ (3,568)
State and Local Jurisdiction [Member]
Deferred Tax Assets and Liabilities [Line Items]
Operating Loss Carryforwards	[1]	10,813
State and Local Jurisdiction [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Federal, state and foreign carryforwards		40
Operating Loss Carryforwards		$ 583
Minimum [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate		2,018
Maximum [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Deferred Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Operating Loss and Tax Credit Carry Forwards, Domestic Federal and State, ExpirationDate		2,036
[1]	The federal net operating loss carryforwards relate principally to net operating loss carryforwards of subsidiaries that are tax residents in both the United States and the United Kingdom. The federal net operating loss carryforwards were generated prior to Berkshire Hathaway Inc.'s ownership and will begin to expire in 2023.

Income Taxes - MidAmerican F199

Income Taxes - MidAmerican Funding - Net Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 128	$ 198
Additions based on tax positions related to the current year	6	7
Additions for tax positions of prior years	70	6
Reductions for tax positions of prior years	(18)	(11)
Statute of limitations	(4)	(1)
Settlements	(1)	(67)
Interest and penalties	0	(4)
Ending balance	181	128
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	158	104
MidAmerican Funding, LLC and Subsidiaries [Domain]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	10	10
Additions based on tax positions related to the current year	1	0
Additions for tax positions of prior years	23	10
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	(4)	(2)
Reductions for tax positions of prior years	(19)	(8)
Interest and penalties	1	0
Ending balance	12	$ 10
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 39

Income Taxes Income Taxes - NPC

Income Taxes Income Taxes - NPC - Tax Reform (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 8,242	$ 13,879
Regulatory Liabilities		7,511	3,120
Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[1]	$ 4,143	$ 25
Nevada Power Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 767	$ 1,474
Regulatory Liabilities		1,121	453
Nevada Power Company [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	$ 670	$ 9
Tax Cuts and Jobs Act of 2017 [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 7,115
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	$ 5,950
Tax Cuts and Jobs Act of 2017 [Member] | Nevada Power Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 787
Tax Cuts and Jobs Act of 2017 [Member] | Nevada Power Company [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	$ 792
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Income Taxes - NPC - Components

Income Taxes - NPC - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Current federal tax expense (benefit)	$ (573)	$ (687)	$ (816)
Deferred federal income tax expense (benefit)	26	1,098	1,274
Other Tax Expense (Benefit)	(7)	(8)	(8)
Income tax (benefit) expense	(554)	403	450
Nevada Power Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Current federal tax expense (benefit)	62	68	0
Deferred federal income tax expense (benefit)	95	79	163
Other Tax Expense (Benefit)	(1)	(1)	(1)
Income tax (benefit) expense	$ 156	$ 146	$ 162

Income Taxes - NPC - Reconcilia

Income Taxes - NPC - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	31.00%	0.00%	0.00%
Other, net	(2.00%)	(2.00%)	(2.00%)
Effective income tax rate	(22.00%)	14.00%	16.00%
Nevada Power Company [Member]
Income Tax Contingency [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Merger Charges, Percent	1.00%	0.00%	1.00%
Other, net	1.00%	(1.00%)	0.00%
Effective income tax rate	38.00%	34.00%	36.00%
Tax Cuts and Jobs Act of 2017 [Member]
Income Tax Contingency [Line Items]
Federal statutory income tax rate	21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Nevada Power Company [Member]
Income Tax Contingency [Line Items]
Federal statutory income tax rate	21.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	1.00%	0.00%	0.00%

Income Taxes - NPC - Compone203

Income Taxes - NPC - Components of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	$ 1,707	$ 909
Employee benefits	45	209
Other	448	707
Total deferred income tax assets	3,543	3,167
Valuation allowances	(126)	(64)
Property-related items	(9,950)	(14,237)
Regulatory assets	(651)	(1,449)
Other	(215)	(334)
Total deferred income tax liabilities	(11,659)	(16,982)
Net deferred income tax liability	(8,242)	(13,879)
Nevada Power Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	201	83
Deferred Tax Assets, Tax Deferred Expense, Leases	100	170
Employee benefits	18	29
Deferred Tax Assets, Customer Advances	14	23
Deferred Tax Assets, Operating Loss and Credit Carryforwards, Federal	0	5
Other	6	16
Total deferred income tax assets	339	326
Valuation allowances	0	(5)
Deferred Tax Assets, Net	339	321
Property-related items	(796)	(1,293)
Regulatory assets	(206)	(321)
Deferred Tax Liabilities, Tax Deferred Expense, Leases	(97)	(165)
Other	(7)	(16)
Total deferred income tax liabilities	(1,106)	(1,795)
Net deferred income tax liability	$ (767)	$ (1,474)

Income Taxes Income Taxes - SPP

Income Taxes Income Taxes - SPPC - Tax Reform (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 8,242	$ 13,879
Regulatory Liabilities		7,511	3,120
Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[1]	$ 4,143	$ 25
Sierra Pacific Power Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Deferred Tax Liabilities, Net		$ 330	$ 617
Regulatory Liabilities		$ 500	$ 290
Tax Cuts and Jobs Act of 2017 [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Deferred Tax Liabilities, Net	[2]	$ 7,115
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Regulatory Liabilities	[2]	$ 5,950
Tax Cuts and Jobs Act of 2017 [Member] | Sierra Pacific Power Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Sierra Pacific Power Company [Member] | Deferred Income Tax Charge [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Deferred Tax Liabilities, Net	[2]	$ 342
Regulatory Liabilities	[2]	$ 341
[1]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.
[2]	(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 10 for further discussion of 2017 Tax Reform impacts.

Income Taxes - SPPC - Component

Income Taxes - SPPC - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of Income Tax Expense (Benefit) [Line Items]
Deferred Federal Income Tax Expense (Benefit)	$ (76)	$ 1,164	$ 1,310
Other Tax Expense (Benefit)	(7)	(8)	(8)
Income tax (benefit) expense	(554)	403	450
Sierra Pacific Power Company [Member]
Components of Income Tax Expense (Benefit) [Line Items]
Deferred Federal Income Tax Expense (Benefit)	56	50	48
Other Tax Expense (Benefit)	(1)	(1)	(1)
Income tax (benefit) expense	$ 55	$ 49	$ 47

Income Taxes - SPPC - Reconcili

Income Taxes - SPPC - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	31.00%	0.00%	0.00%
Other, net	(2.00%)	(2.00%)	(2.00%)
Effective income tax rate	(22.00%)	14.00%	16.00%
Sierra Pacific Power Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation Regulatory Differences	0.00%	1.00%	1.00%
Other, net	0.00%	1.00%	0.00%
Effective income tax rate	34.00%	37.00%	36.00%
Tax Cuts and Jobs Act of 2017 [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Sierra Pacific Power Company [Member]
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	21.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	(1.00%)	0.00%	0.00%

Income Taxes - SPPC - Compon207

Income Taxes - SPPC - Components of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	$ 1,707	$ 909
Employee benefits	45	209
Derivative contracts	2	29
Other	448	707
Total deferred income tax assets	3,543	3,167
Property-related items	(9,950)	(14,237)
Regulatory assets	(651)	(1,449)
Other	(215)	(334)
Total deferred income tax liabilities	(11,659)	(16,982)
Net deferred income tax liability	(8,242)	(13,879)
Sierra Pacific Power Company [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	67	16
Deferred Tax Assets, Operating Loss and Credit Carryforwards, Federal	10	25
Employee benefits	10	22
Deferred Tax Assets, Tax Deferred Expense, Leases	7	12
Deferred Tax Assets, Customer Advances	7	9
Derivative contracts	0	5
Other	6	6
Total deferred income tax assets	107	95
Property-related items	(349)	(562)
Regulatory assets	(74)	(124)
Deferred Tax Liabilities, Tax Deferred Expense, Leases	(7)	(12)
Other	(7)	(14)
Total deferred income tax liabilities	(437)	(712)
Net deferred income tax liability	$ (330)	$ (617)

Income Taxes - SPPC - Summary o

Income Taxes - SPPC - Summary of Operating Loss Carryforwards (Details) - Sierra Pacific Power Company [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 18
Deferred Tax Assets, Operating Loss Carryforwards	4
Deferred Tax Assets, Tax Credit Carryforwards	$ 6
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2033
Tax Credit Carryforward, Expiration Date	Dec. 31, 2021
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2033
Tax Credit Carryforward, Expiration Date	Dec. 31, 2032

Supplemental Cash Flow Discl209

Supplemental Cash Flow Disclosures (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized		$ 1,715	$ 1,673	$ 1,764
Income Taxes Paid, Net	[1]	(540)	(1,016)	(1,666)
Related Party Transaction, Cash Received for Income Taxes, Net		600	1,100	1,781
Capital Expenditures Incurred but Not yet Paid		653	547	718
Capital Expenditures Incurred Deferred Payments		$ 100	$ 0	$ 0
[1]	Includes $636 million, $1.1 billion and $1.8 billion of income taxes received from Berkshire Hathaway in 2017, 2016 and 2015, respectively.

Supplemental Cash Flow Discl210

Supplemental Cash Flow Disclosures - PacifiCorp (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		$ 1,715	$ 1,673	$ 1,764
Income Taxes Paid, Net	[1]	(540)	(1,016)	(1,666)
Accruals related to property, plant and equipment additions		653	547	718
PacifiCorp [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		350	350	342
Income Taxes Paid, Net		340	201	40
Accruals related to property, plant and equipment additions		147	101	147
Accounts receivable related to property, plant and equipment sales		$ 0	$ 0	$ 40
[1]	Includes $636 million, $1.1 billion and $1.8 billion of income taxes received from Berkshire Hathaway in 2017, 2016 and 2015, respectively.

Supplemental Cash Flow Discl211

Supplemental Cash Flow Disclosures - MEC (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		$ 1,715	$ 1,673	$ 1,764
Income taxes received, net	[1]	540	1,016	1,666
Accruals related to property, plant and equipment additions		653	547	718
MidAmerican Energy Company [Member]
Condensed Income Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		193	181	154
Income taxes received, net		465	601	629
Accruals related to property, plant and equipment additions		224	131	249
Dividend, Noncash, Transfer Of Operations		$ 0	$ 90	$ 0
[1]	Includes $636 million, $1.1 billion and $1.8 billion of income taxes received from Berkshire Hathaway in 2017, 2016 and 2015, respectively.

Supplemental Cash Flow Discl212

Supplemental Cash Flow Disclosures - MidAmerican Funding (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		$ 1,715	$ 1,673	$ 1,764
Income taxes received, net	[1]	540	1,016	1,666
Accruals related to property, plant and equipment additions		653	547	718
MidAmerican Funding, LLC and Subsidiaries [Domain]
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized		218	204	177
Income taxes received, net		472	609	630
Accruals related to property, plant and equipment additions		224	131	249
Dividend, Noncash, Transfer Of Operations		$ 0	$ 90	$ 0
[1]	Includes $636 million, $1.1 billion and $1.8 billion of income taxes received from Berkshire Hathaway in 2017, 2016 and 2015, respectively.

Supplemental Cash Flow Discl213

Supplemental Cash Flow Disclosures - NPC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized	$ 1,715	$ 1,673	$ 1,764
Accruals related to property, plant and equipment additions	653	547	718
Nevada Power Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized	167	173	186
Income Taxes Paid	89	0	0
Accruals related to property, plant and equipment additions	18	19	51
Capital and Financial Lease Obligations Incurred	$ 0	$ (1)	$ (5)

Supplemental Cash Flow Discl214

Supplemental Cash Flow Disclosures - SPPC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized	$ 1,715	$ 1,673	$ 1,764
Accruals related to property, plant and equipment additions	653	547	718
Sierra Pacific Power Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid, net of amounts capitalized	40	47	54
Accruals related to property, plant and equipment additions	10	15	24
Capital and Financial Lease Obligations Incurred	$ 1	$ 0	$ 13

Related Party Transactions - Pa

Related Party Transactions - PacifiCorp (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Income Taxes Receivable From (Payable To) Related Parties Current	$ 334	$ (27)
Related Party Transaction, Cash Received for Income Taxes, Net	600	1,100	$ 1,781
PacifiCorp [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	11	10	10
Due to Affiliate, Current	2		2
Related Party Transaction, Expense Reimbursement	3	4	7
Due from Affiliate, Current	1
PacifiCorp [Member] | Subsidiary of Common Parent [Member]
Related Party Transaction [Line Items]
Due to Affiliate, Current		1	1
Purchases from Related Party	6	7	8
Revenue from Related Parties	1	1	2
PacifiCorp [Member] | BNSF Railway Company [Member]
Related Party Transaction [Line Items]
Due to Affiliate, Current	3	1
Purchases from Related Party	35	37	39
PacifiCorp [Member] | MEHC Insurance Services Ltd. [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Proceeds From Insurance Claims	0	0	2
PacifiCorp [Member] | BHE [Member]
Related Party Transaction [Line Items]
Income Taxes Receivable From (Payable To) Related Parties Current	59	17
Related Party Transaction, Cash Received for Income Taxes, Net	(340)	(201)	(40)
PacifiCorp [Member] | Bridger Coal Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expense Reimbursement	2	2	19
Due from Affiliate, Current	5
PacifiCorp [Member] | Equity Method Investee [Member]
Related Party Transaction [Line Items]
Due to Affiliate, Current	18	17
Purchases from Related Party	$ 170	$ 174	$ 181

Related Party Transactions R216

Related Party Transactions Related Party Transactions - MEC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Income Taxes Receivable From (Payable To) Related Parties Current	$ 334	$ (27)
Related Party Transaction, Cash Received for Income Taxes, Net	600	1,100	$ 1,781
MidAmerican Energy Company [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expense Reimbursement	53	41	46
Due from Affiliate, Current	9	5
Due to Affiliate, Current	16	13
Due from Affiliate, Noncurrent	16	12
Due to Affiliate, Noncurrent	45	36
MidAmerican Energy Company [Member] | BHE [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	9	6	7
Income Taxes Receivable From (Payable To) Related Parties Current	51	(6)
Related Party Transaction, Cash Received for Income Taxes, Net	465	601	629
MidAmerican Energy Company [Member] | Northern Natural Gas and BNSF Railway Company [Member]
Related Party Transaction [Line Items]
Purchases from Related Party	$ 122	$ 135	$ 165

Related Party Transactions - Mi

Related Party Transactions - MidAmerican Funding (Details) $ in Millions		12 Months Ended
		Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Related Party Transaction [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 9,051	$ 6,345
Income Taxes Receivable From (Payable To) Related Parties Current		334	(27)
Related Party Transaction, Cash Received for Income Taxes, Net		600	1,100	$ 1,781
MidAmerican Funding, LLC and Subsidiaries [Domain]
Related Party Transaction [Line Items]
Notes Payable, Related Parties, Current		$ 164	31
Maximum Debt to Capitalization Ratio		0.67
Minumum Interest Coverage Ratio		2.2
MidAmerican Funding, LLC and Subsidiaries [Domain] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expense Reimbursement		$ 46	35	35
Due from Affiliate, Current		9	7
Due to Affiliate, Current		14	12
Due from Affiliate, Noncurrent		16	12
Due to Affiliate, Noncurrent		45	36
MidAmerican Funding, LLC and Subsidiaries [Domain] | BHE [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party		9	6	7
Income Taxes Receivable From (Payable To) Related Parties Current		64	(7)
Related Party Transaction, Cash Received for Income Taxes, Net		472	609	631
MidAmerican Funding, LLC and Subsidiaries [Domain] | Northern Natural Gas and BNSF Railway Company [Member]
Related Party Transaction [Line Items]
Purchases from Related Party		122	135	$ 165
MidAmerican Funding, LLC and Subsidiaries [Domain] | Revolving Credit Arrangement, $300 million [Member] | Line of Credit [Member] | MHC, Inc. [Member] | BHE [Member]
Related Party Transaction [Line Items]
Line of Credit Arrangement Offered to Affiliate, Maximum Amount Available		300
Notes Payable, Related Parties, Current		$ 164	$ 31
Debt, Weighted Average Interest Rate		1.629%	0.885%
MidAmerican Funding, LLC and Subsidiaries [Domain] | Revolving Credit Arrangement, $100 million [Member] | Line of Credit [Member] | MHC, Inc. [Member] | BHE [Member]
Related Party Transaction [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 100
Notes Receivable, Related Parties, Current		$ 0	$ 0
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.

Related Party Transactions - NP

Related Party Transactions - NPC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Income Taxes Receivable From (Payable To) Related Parties Current	$ 334	$ (27)
Related Party Transaction, Cash Received for Income Taxes, Net	600	1,100	$ 1,781
Nevada Power Company [Member] | Kern River [Member]
Related Party Transaction [Line Items]
Purchases from Related Party	66	68	68
Due to Affiliate, Current	5	5
Nevada Power Company [Member] | Sierra Pacific Power Company [Member]
Related Party Transaction [Line Items]
Due from Affiliates	5	4
Due to Affiliate	0	0
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	17	14	16
Related Party Transaction, Expense Reimbursement	27	24	22
Nevada Power Company [Member] | NV Energy, Inc. [Member]
Related Party Transaction [Line Items]
Due from Affiliates	0	0
Due to Affiliate	29	32
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	10	10	12
Related Party Transaction, Expense Reimbursement	0	1	1
Income Taxes Receivable From (Payable To) Related Parties Current	38	68
Related Party Transaction, Cash Received for Income Taxes, Net	89	0	0
Nevada Power Company [Member] | Berkshire Hathaway Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	2	2	2
Nevada Power Company [Member] | Electric Distribution [Member] | PacifiCorp [Member]
Related Party Transaction [Line Items]
Purchases from Related Party	0	0	2
Revenue from Related Parties	3	2	3
Due from Affiliates	0	0
Due to Affiliate	0	0
Nevada Power Company [Member] | Electric Distribution [Member] | Sierra Pacific Power Company [Member]
Related Party Transaction [Line Items]
Purchases from Related Party	21	17	2
Revenue from Related Parties	104	78	$ 69
Due from Affiliates	10	45
Due to Affiliate	$ 0	$ 12

Related Party Transactions - SP

Related Party Transactions - SPPC (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Income Taxes Receivable From (Payable To) Related Parties Current	$ 334,000,000	$ (27,000,000)
Related Party Transaction, Cash Received for Income Taxes, Net	600,000,000	1,100,000,000	$ 1,781,000,000
Sierra Pacific Power Company [Member] | BHE [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	1,000,000	1,000,000	1,000,000
Sierra Pacific Power Company [Member] | NV Energy, Inc. [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	5,000,000	5,000,000	6,000,000
Due from Affiliates	0	0
Due to Affiliate	17,000,000	18,000,000
Income Taxes Receivable From (Payable To) Related Parties Current	0	0	0
Related Party Transaction, Cash Received for Income Taxes, Net	0	0	0
Sierra Pacific Power Company [Member] | Nevada Power Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	27,000,000	24,000,000	22,000,000
Related Party Transaction, Expense Reimbursement	17,000,000	14,000,000	16,000,000
Due from Affiliates	0	0
Due to Affiliate	5,000,000	4,000,000
Sierra Pacific Power Company [Member] | Electric Distribution [Member] | Nevada Power Company [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	21,000,000	17,000,000	2,000,000
Purchases from Related Party	104,000,000	78,000,000	$ 69,000,000
Due from Affiliates	0	12,000,000
Due to Affiliate	$ 10,000,000	$ 45,000,000

Employee Benefit Plans - Net Pe

Employee Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member] | UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 23	$ 20	$ 24
Defined Benefit Plan, Interest Cost	58	72	79
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(100)	(110)	(116)
Defined Benefit Plan, Accumulated Benefit Obligation, (Increase) Decrease for Settlement and Curtailment	31	0	0
Defined Benefit Plan Net Amortization	63	44	62
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	75	26	49
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	4	7
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(160)	(160)	(169)
Defined Benefit Plan Net Amortization	25	46	53
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	5	41	38
Pension Plan [Member] | Domestic Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	9	10	12
Defined Benefit Plan, Interest Cost	31	34	32
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(44)	(44)	(46)
Defined Benefit Plan Net Amortization	2	2	2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(2)	2	0
Pension Plan [Member] | Domestic Plan [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(6)	(2)	(4)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	(7)	(7)
Defined Benefit Plan, Service Cost	9	9	11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(40)	(41)	(45)
Defined Benefit Plan Net Amortization	(14)	(12)	(11)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(16)	(13)	(14)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	5	5	7
Defined Benefit Plan, Interest Cost	9	10	9
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(14)	(13)	(15)
Defined Benefit Plan Net Amortization	(4)	(4)	(3)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(4)	(2)	(2)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (1)	$ (1)	$ 0

Employee Benefit Plans - Funded

Employee Benefit Plans - Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Fair Value of Plan Assets	$ 666	$ 662	$ 662	$ 736	$ 666
Defined Benefit Plan, Benefit Obligation	734	740	740	721	734
Defined Benefit Plan, Funded (Unfunded) Status of Plan				15	(68)
Other assets				32	19
Other current liabilities				0	0
Liability, Defined Benefit Plan, Noncurrent				(17)	(87)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				15	(68)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	666	662
Defined Benefit Plan, Plan Assets, Contributions by Employer	5	2
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	106	41
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(51)	(49)
Ending balance	736	666	662
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	734	740
Defined Benefit Plan, Service Cost	9	9	11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(10)	(7)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	0
Benefits Paid	(51)	(49)
Ending balance	721	734	740
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	0	0
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets				126	413
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Benefit Obligation				143	500
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount				272	242
UNITED KINGDOM | Pension Plan [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Fair Value of Plan Assets	2,169	2,276	2,276	2,368	2,169
Defined Benefit Plan, Benefit Obligation	2,125	2,142	2,142	2,201	2,125
Defined Benefit Plan, Funded (Unfunded) Status of Plan				167	44
Other assets				167	44
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,169	2,276
Defined Benefit Plan, Plan Assets, Contributions by Employer	58	55
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	1	1
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	145	349
Defined Benefit Plan, Plan Assets, Payment for Settlement	(144)	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(68)	(115)
Foreign Currency Exchange Rate Changes	(207)	(397)
Ending balance	2,368	2,169	2,276
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	2,125	2,142
Defined Benefit Plan, Service Cost	23	20	24
Defined Benefit Plan, Interest Cost	58	72	79
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	1	1
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(4)	387
Benefits Paid	(68)	(115)
Foreign currency exchange rate changes	197	(382)
Ending balance	2,201	2,125	2,142
Defined Benefit Plan, Accumulated Benefit Obligation				1,933	1,858
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	(131)	0
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Fair Value of Plan Assets	2,525	2,489	2,489	2,761	2,525
Defined Benefit Plan, Benefit Obligation	2,952	2,934	2,934	3,006	2,952
Defined Benefit Plan, Funded (Unfunded) Status of Plan				(245)	(427)
Other assets				66	26
Other current liabilities				(14)	(15)
Liability, Defined Benefit Plan, Noncurrent				(297)	(438)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				(245)	(427)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,525	2,489
Defined Benefit Plan, Plan Assets, Contributions by Employer	64	78
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	390	163
Defined Benefit Plan, Plan Assets, Payment for Settlement	(15)	(11)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(203)	(194)
Ending balance	2,761	2,525	2,489
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	2,952	2,934
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	132	67
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	1
Benefits Paid	(203)	(194)
Ending balance	3,006	2,952	$ 2,934
Defined Benefit Plan, Accumulated Benefit Obligation				2,988	2,929
Defined Benefit Plan, Benefit Obligation, Payment for Settlement	$ (15)	$ (11)
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets				2,016	1,841
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Benefit Obligation				2,327	2,294
Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation				$ 2,316	$ 2,278

Employee Benefit Plans - Unreco

Employee Benefit Plans - Unrecognized Amounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	$ 16
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	33
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	16
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	(2)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	15
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax			$ 14	$ 88
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax			(37)	(52)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax			7	7
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	43	$ 37	(16)	43
Beginning balance	43	37
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	73	(6)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	15
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	14	(12)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(59)	6
Ending balance	(16)	43
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	1
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	15
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	1
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	(13)
Other Postretirement Benefits Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	55	49	10	55
Beginning balance	55	49
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(52)	(5)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	7	(11)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(45)	6
Ending balance	10	55
Other Postretirement Benefits Plan [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(12)	(12)	(26)	(12)
Beginning balance	(12)	(12)
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	21	(1)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(7)	(1)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(14)	0
Ending balance	(26)	(12)
Pension Plan [Member] | UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax			510	590
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	60
Pension Plan [Member] | UNITED KINGDOM | Accumulated Other Comprehensive Income (Loss) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	590	592	510	590
Beginning balance	590	592
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(50)	(148)
Defined Benefit Plan, Accumulated Benefit Obligation, (Increase) Decrease for Settlement and Curtailment	(17)	0
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	63	(44)
Foreign currency exchange rate changes	50	(106)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(80)	(2)
Ending balance	510	590
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax			649	775
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax			(3)	(7)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax			(4)	(7)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	761	741	642	761
Beginning balance	761	741
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	94	(65)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	1	1
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	25	46
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(119)	20
Ending balance	642	761
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	32
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	1	1
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	(3)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	28
Pension Plan [Member] | Domestic Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	761	729	665	761
Beginning balance	761	729
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(68)	76
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		1
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(28)	45
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(96)	32
Ending balance	665	761
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		1
Pension Plan [Member] | Domestic Plan [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(13)	(1)	(43)	(13)
Beginning balance	(13)	(1)
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	29	(11)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		0
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	1	(1)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(30)	(12)
Ending balance	(43)	(13)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		0
Pension Plan [Member] | Domestic Plan [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	13	13	$ 20	$ 13
Beginning balance	13	13
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	3	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		0
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	4	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	7	0
Ending balance	$ 20	13
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		$ 0

Employee Benefit Plans - Plan A

Employee Benefit Plans - Plan Assumptions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	7.10%	7.40%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%	5.00%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2,025	2,025
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	$ 0
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	0
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	4
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	$ (4)
Pension Plan [Member] | UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.60%	2.70%	3.70%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	3.45%	3.00%	2.90%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Rate Of Future Price Inflation	2.95%	3.00%	2.90%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.70%	3.70%	3.60%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	5.00%	5.60%	5.60%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.00%	2.90%	2.80%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Rate of Future Price Inflation	3.00%	2.90%	2.80%
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	4.06%	4.43%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	2.75%	2.75%	2.75%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.06%	4.43%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.55%	6.78%	6.88%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	2.75%	2.75%	2.75%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.57%	4.01%	4.33%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.01%	4.33%	3.93%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.73%	7.03%	7.00%

Employee Benefit Plans - Contri

Employee Benefit Plans - Contributions and Benefit Payments (Details) - Dec. 31, 2017 £ in Millions, $ in Millions	USD ($)	GBP (£)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 3
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	54
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	55
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	57
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	55
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	54
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	243
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	39
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	226
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	224
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	224
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	222
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	214
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	979
UNITED KINGDOM | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year | £		£ 45
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	72
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	74
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	75
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	77
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	79
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 427

Employee Benefit Plans - Asset

Employee Benefit Plans - Asset Allocations (Details)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Other Postretirement Benefits Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of Investment Funds Comprised Of Equity Securitites		68.00%	63.00%
Percentage of Investment Funds Comprised Of Debt Securities		32.00%	37.00%
Other Postretirement Benefits Plan [Member] | NV Energy, Inc. [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	[1]	4000.00%
Other Postretirement Benefits Plan [Member] | NV Energy, Inc. [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	[1]	6000.00%
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of Investment Funds Comprised Of Equity Securitites		62.00%	62.00%
Percentage of Investment Funds Comprised Of Debt Securities		38.00%	38.00%
UNITED KINGDOM | Pension Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of Investment Funds Comprised Of Equity Securitites		21.00%	44.00%
Percentage of Investment Funds Comprised Of Debt Securities		79.00%	56.00%
Minimum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.33
Minimum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.61
Minimum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.01
Minimum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.00
Minimum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.25
Minimum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.5
Minimum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.00
Minimum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.00
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.33
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.53
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.08
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.00
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.20
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.60
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.02
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.00
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | NV Energy, Inc. [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.53
Minimum [Member] | Domestic Plan [Member] | Pension Plan [Member] | NV Energy, Inc. [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.23
Minimum [Member] | UNITED KINGDOM | Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.50
Minimum [Member] | UNITED KINGDOM | Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.35
Minimum [Member] | UNITED KINGDOM | Pension Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.05
Maximum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.37
Maximum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.65
Maximum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.03
Maximum [Member] | Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.01
Maximum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.45
Maximum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.80
Maximum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		0
Maximum [Member] | Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.05
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.37
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	.57
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.12
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.01
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.4
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.8
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.08
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.05
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | NV Energy, Inc. [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.77
Maximum [Member] | Domestic Plan [Member] | Pension Plan [Member] | NV Energy, Inc. [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	[1]	0.47
Maximum [Member] | UNITED KINGDOM | Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.55
Maximum [Member] | UNITED KINGDOM | Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.40
Maximum [Member] | UNITED KINGDOM | Pension Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage		.15
[1]	For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.

Employee Benefit Plans - Fair V

Employee Benefit Plans - Fair Value Measurements (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)		$ 106		$ 41
Defined Benefit Plan, Plan Assets, Payment for Settlement		0		0
Defined Benefit Plan, Fair Value of Plan Assets		736		666		$ 662
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		443		411
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		115		95
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		14		20
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		11		18	[1]
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		3		2	[1]
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20		19
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20		19
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		36		29
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		36		29
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		46		39
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		46		39
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		29		25
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		29		25
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		185		217
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		185		217	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		8		5
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		8		5	[1]
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 220		$ 152
Percentage of Investment Funds Comprised Of Equity Securitites		68.00%		63.00%
Percentage of Investment Funds Comprised Of Debt Securities		32.00%		37.00%
Percentage Of Investment Funds Invested in United States Securities		73.00%		72.00%
Percentage Of Investment Funds Invested In International Securities		27.00%		28.00%
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 219		$ 152
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1		0
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1],[2]
Other Postretirement Benefits Plan [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		558		506
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		736		666
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		174		156	[2]
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		4		4
UNITED KINGDOM | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)		145		349
Defined Benefit Plan, Plan Assets, Payment for Settlement		(144)		0
Defined Benefit Plan, Fair Value of Plan Assets		2,368		2,169		2,276
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)		207		397
UNITED KINGDOM | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	874		722
UNITED KINGDOM | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,057		1,178
UNITED KINGDOM | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	230		105
UNITED KINGDOM | Pension Plan [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		34		87
UNITED KINGDOM | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		4		4	[3]
UNITED KINGDOM | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	30		83
UNITED KINGDOM | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	0		0
UNITED KINGDOM | Pension Plan [Member] | United Kingdom Government Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		870		718
UNITED KINGDOM | Pension Plan [Member] | United Kingdom Government Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		870		718
UNITED KINGDOM | Pension Plan [Member] | United Kingdom Government Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	[3]	0
UNITED KINGDOM | Pension Plan [Member] | United Kingdom Government Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
UNITED KINGDOM | Pension Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	$ 1,027		$ 1,095
Percentage of Investment Funds Comprised Of Equity Securitites		21.00%		44.00%
Percentage of Investment Funds Comprised Of Debt Securities		79.00%		56.00%
UNITED KINGDOM | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3],[4]	$ 0		$ 0
UNITED KINGDOM | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,027		1,095
UNITED KINGDOM | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[3],[4]
UNITED KINGDOM | Pension Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		230		105
UNITED KINGDOM | Pension Plan [Member] | Real Estate Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
UNITED KINGDOM | Pension Plan [Member] | Real Estate Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
UNITED KINGDOM | Pension Plan [Member] | Real Estate Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		230	[3]	105	[3]	204	$ 199
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held		6		10		18
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchases, Sales, and Settlements		104		(80)		0
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)		15		(29)		(13)
UNITED KINGDOM | Pension Plan [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2,161		2,005
UNITED KINGDOM | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2,368		2,169
UNITED KINGDOM | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	207		164
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)		390		163
Defined Benefit Plan, Plan Assets, Payment for Settlement		(15)		(11)
Defined Benefit Plan, Fair Value of Plan Assets		2,761		2,525		$ 2,489
Domestic Plan [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,069		1,011
Domestic Plan [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		572		483	[5]
Domestic Plan [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		86		58
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		10		4
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		76		54
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		218		161
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		218		161
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				2
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets				0
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]			2
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]			0
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		350		295
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		350		295	[5]
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16		20
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16		20
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		110		112
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		110		112
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		622		583
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		622		583	[5]
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		136		117
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		136		117
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 103		$ 146	[6]
Percentage of Investment Funds Comprised Of Equity Securitites		62.00%		62.00%
Percentage of Investment Funds Comprised Of Debt Securities		38.00%		38.00%
Percentage Of Investment Funds Invested in United States Securities		68.00%		60.00%
Percentage Of Investment Funds Invested In International Securities		32.00%		40.00%
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 83		$ 146	[5],[6]
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20		0
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[5],[6]
Domestic Plan [Member] | Pension Plan [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,641		1,494
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2,761		2,525
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,019		920	[6]
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		63		61	[7]
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 38		$ 50
[1]	Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.
[2]	Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 68% and 32%, respectively, for 2017 and 63% and 37%, respectively, for 2016. Additionally, these funds are invested in United States and international securities of approximately 73% and 27%, respectively, for 2017 and 72% and 28%, respectively, for 2016.
[3]	Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.
[4]	Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 21% and 79%, respectively, for 2017 and 44% and 56%, respectively, for 2016.
[5]	Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.
[6]	Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 62% and 38%, respectively, for both 2017 and 2016. Additionally, these funds are invested in United States and international securities of approximately 68% and 32%, respectively, for 2017 and 60% and 40%, respectively, for 2016.
[7]	Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital.

Employee Benefit Plans - Level

Employee Benefit Plans - Level 3 Rollforward (Details) - UNITED KINGDOM - Pension Plan [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance		$ 2,169		$ 2,276
Foreign Currency Exchange Rate Changes		207		397
Ending balance		2,368		2,169		$ 2,276
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	[1]	105
Ending balance	[1]	230		105
Real Estate Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance		105
Ending balance		230		105
Real Estate Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance		105	[1]	204		199
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held		6		10		18
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchases, Sales, and Settlements		104		(80)		0
Foreign Currency Exchange Rate Changes		15		(29)		(13)
Ending balance		$ 230	[1]	$ 105	[1]	$ 204
[1]	Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.

Employee Benefit Plans - Define

Employee Benefit Plans - Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost	$ 103	$ 102	$ 90

Employee Benefit Plans - Pacifi

Employee Benefit Plans - PacifiCorp - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 9	$ 9	$ 11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(40)	(41)	(45)
Defined Benefit Plan Net Amortization	(14)	(12)	(11)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(16)	(13)	(14)
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	2	2	3
Defined Benefit Plan, Interest Cost	14	15	16
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(21)	(21)	(23)
Defined Benefit Plan Net Amortization	(6)	(5)	(4)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(11)	(9)	(8)
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(160)	(160)	(169)
Defined Benefit Plan Net Amortization	25	46	53
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	5	41	38
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	0	4	4
Defined Benefit Plan, Interest Cost	49	54	53
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(72)	(75)	(77)
Defined Benefit Plan Net Amortization	14	34	42
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (9)	$ 17	$ 22

Employee Benefit Plans - Pac230

Employee Benefit Plans - PacifiCorp - Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	$ 666	$ 662
Defined Benefit Plan, Plan Assets, Contributions by Employer	5	2
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	106	41
Defined Benefit Plan, Plan Assets, Payment for Settlement	0	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(51)	(49)
Ending balance	736	666	$ 662
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	734	740
Defined Benefit Plan, Service Cost	9	9	11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(10)	(7)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(51)	(49)
Defined Benefit Plan, Benefit Obligation	734	740	740	$ 721	$ 734
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				15	(68)
Assets for Plan Benefits, Defined Benefit Plan				32	19
Other current liabilities				0	0
Liability, Defined Benefit Plan, Noncurrent				(17)	(87)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				15	(68)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount				272	242
PacifiCorp [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	302	305
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	1
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	7	6
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	49	17
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(27)	(27)
Ending balance	332	302	305
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	358	362
Defined Benefit Plan, Service Cost	2	2	3
Defined Benefit Plan, Interest Cost	14	15	16
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	7	6
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(23)	0
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(27)	(27)
Defined Benefit Plan, Benefit Obligation	358	362	362	331	358
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				1	(56)
Assets for Plan Benefits, Defined Benefit Plan				1	0
Other current liabilities				0	0
Liability, Defined Benefit Plan, Noncurrent				0	(56)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				1	(56)
PacifiCorp [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount				60	55
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,525	2,489
Defined Benefit Plan, Plan Assets, Contributions by Employer	64	78
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	390	163
Defined Benefit Plan, Plan Assets, Payment for Settlement	(15)	(11)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(203)	(194)
Ending balance	2,761	2,525	2,489
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	2,952	2,934
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	132	67
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(203)	(194)
Defined Benefit Plan, Benefit Obligation	2,952	2,934	2,934	3,006	2,952
Defined Benefit Plan, Accumulated Benefit Obligation				2,988	2,929
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				(245)	(427)
Assets for Plan Benefits, Defined Benefit Plan				66	26
Other current liabilities				(14)	(15)
Liability, Defined Benefit Plan, Noncurrent				(297)	(438)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				(245)	(427)
Domestic Plan [Member] | PacifiCorp [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	999	1,043
Defined Benefit Plan, Plan Assets, Contributions by Employer	54	5
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	166	51
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(108)	(100)
Ending balance	1,111	999	1,043
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	1,276	1,289
Defined Benefit Plan, Service Cost	0	4	4
Defined Benefit Plan, Interest Cost	49	54	53
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	34	29
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(108)	(100)
Defined Benefit Plan, Benefit Obligation	$ 1,276	$ 1,289	$ 1,289	1,251	1,276
Defined Benefit Plan, Accumulated Benefit Obligation				1,251	1,276
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan				(140)	(277)
Assets for Plan Benefits, Defined Benefit Plan				5	0
Other current liabilities				(4)	(5)
Liability, Defined Benefit Plan, Noncurrent				(141)	(272)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position				$ (140)	$ (277)

Employee Benefit Plans - Pac231

Employee Benefit Plans - PacifiCorp - Unrecognized Amounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	$ 33
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(16)
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	(2)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	15
PacifiCorp [Member]
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	16
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(6)
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	(1)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	9
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	14	$ 88
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(37)	(52)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	7	7
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(16)	43	$ 37
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	73	(6)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	14	(12)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(59)	6
Defined Benefit Plan, Amortization of Gains (Losses), Net	1
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(15)
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	1
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	(13)
Other Postretirement Benefits Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	10	55	49
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(52)	(5)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	7	(11)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(45)	6
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	(12)	39
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(6)	(13)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	7	8
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(11)	34
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(6)
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	1
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	(5)
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(11)	34	26
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(51)	3
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	6	5
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(45)	8
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	649	775
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(3)	(7)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	(4)	(7)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	642	761	741
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	94	(65)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	25	46
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(119)	20
Defined Benefit Plan, Amortization of Gains (Losses), Net	32
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(1)	(1)
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	(3)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	28
Domestic Plan [Member] | Pension Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	665	761	729
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(68)	76
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(28)	45
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(96)	32
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		(1)
Domestic Plan [Member] | Pension Plan [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	20	13	13
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	3	0
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	4	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	7	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	442	518
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	0	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	(4)	(7)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	438	511	492
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(59)	53
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(14)	(34)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(73)	19
Defined Benefit Plan, Amortization of Gains (Losses), Net	16
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	0
Defined Benefit Plan, Amortization of Regulatory Deferrals, Net	(2)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	14
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	418	491	473
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(60)	51
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(13)	(33)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(73)	18
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	20	20	$ 19
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	1	2
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(1)	(1)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	$ 0	$ 1

Employee Benefit Plans - Pac232

Employee Benefit Plans - PacifiCorp - Plan Assumptions (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.57%	4.01%	4.33%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.01%	4.33%	3.93%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.73%	7.03%	7.00%
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	4.05%	4.35%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.05%	4.35%	3.99%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	7.25%	7.50%	7.08%
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	4.06%	4.43%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	2.75%	2.75%	2.75%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.06%	4.43%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.55%	6.78%	6.88%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	2.75%	2.75%	2.75%
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	4.05%	4.40%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase			2.75%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.05%	4.40%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	7.25%	7.50%	7.50%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase		2.75%	2.75%

Employee Benefit Plans - Pac233

Employee Benefit Plans - PacifiCorp - Contributions and Benefit Payments (Details) $ in Millions	Dec. 31, 2017USD ($)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 3
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	54
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	55
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	57
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	55
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	54
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	243
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	0
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	25
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	25
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	26
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	23
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	23
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	100
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	39
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	226
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	224
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	224
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	222
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	214
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	979
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	4
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	108
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	107
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	103
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	99
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	94
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 393

Employee Benefit Plans - Pac234

Employee Benefit Plans - PacifiCorp - Asset Allocations (Details) - PacifiCorp [Member]	12 Months Ended
	Dec. 31, 2017	[2]
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.33	[1]
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.61	[1]
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.01
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.37	[1]
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.65	[1]
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.03
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.01
Domestic Plan [Member] | Minimum [Member] | Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.33	[1]
Domestic Plan [Member] | Minimum [Member] | Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.49	[1]
Domestic Plan [Member] | Minimum [Member] | Pension Plan [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.07
Domestic Plan [Member] | Minimum [Member] | Pension Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0
Domestic Plan [Member] | Maximum [Member] | Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.38	[1]
Domestic Plan [Member] | Maximum [Member] | Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.6	[1]
Domestic Plan [Member] | Maximum [Member] | Pension Plan [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.12
Domestic Plan [Member] | Maximum [Member] | Pension Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0.01
[1]	For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.
[2]	PacifiCorp's Retirement Plan trust includes a separate account that is used to fund benefits for the other postretirement benefit plan. In addition to this separate account, the assets for the other postretirement benefit plan are held in Voluntary Employees' Beneficiary Association ("VEBA") trusts, each of which has its own investment allocation strategies. Target allocations for the other postretirement benefit plan include the separate account of the Retirement Plan trust and the VEBA trusts.

Employee Benefit Plans - Pac235

Employee Benefit Plans - PacifiCorp - Fair Value Measurements (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 736	$ 666		$ 662
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		443	411
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		115	95
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		558	506
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		14	20
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		11	18	[1]
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		3	2	[1]
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20	19
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20	19
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		36	29
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		36	29
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[1]
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		46	39
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		46	39
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[1]
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		29	25
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		29	25
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		185	217
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		185	217	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[1]
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		8	5
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		8	5	[1]
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 220	$ 152
Percentage of Investment Funds Comprised Of Equity Securitites		68.00%	63.00%
Percentage of Investment Funds Comprised Of Debt Securities		32.00%	37.00%
Percentage Of Investment Funds Invested in United States Securities		73.00%	72.00%
Percentage Of Investment Funds Invested In International Securities		27.00%	28.00%
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 219	$ 152
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1	0
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[1],[2]
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		332	302		305
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		151	144
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		37	29
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		188	173
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		7	5
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		4	4
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		3	1
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		11	11
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		11	11
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16	13
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16	13
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2	2
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2	2
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16	13
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16	13
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		98	93
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		98	93
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		6	4
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		6	4
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 32	$ 32
Percentage of Investment Funds Comprised Of Equity Securitites		63.00%	62.00%
Percentage of Investment Funds Comprised Of Debt Securities		37.00%	38.00%
Percentage Of Investment Funds Invested in United States Securities		77.00%	71.00%
Percentage Of Investment Funds Invested In International Securities		23.00%	29.00%
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 32	$ 32
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		736	666
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		174	156	[2]
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		4	4
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		332	302
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | PacifiCorp [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	140	125
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | PacifiCorp [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	4	4
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2,761	2,525		2,489
Domestic Plan [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,069	1,011
Domestic Plan [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		572	483	[5]
Domestic Plan [Member] | Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,641	1,494
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		86	58
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		10	4
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		76	54
Domestic Plan [Member] | Pension Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		218	161
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		218	161
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			2
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			0
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]		2
Domestic Plan [Member] | Pension Plan [Member] | Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]		0
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		350	295
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		350	295	[5]
Domestic Plan [Member] | Pension Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16	20
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16	20
Domestic Plan [Member] | Pension Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		110	112
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		110	112
Domestic Plan [Member] | Pension Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		622	583
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		622	583	[5]
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		136	117
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		136	117
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5]
Domestic Plan [Member] | Pension Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 103	$ 146	[6]
Percentage of Investment Funds Comprised Of Equity Securitites		62.00%	62.00%
Percentage of Investment Funds Comprised Of Debt Securities		38.00%	38.00%
Percentage Of Investment Funds Invested in United States Securities		68.00%	60.00%
Percentage Of Investment Funds Invested In International Securities		32.00%	40.00%
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 83	$ 146	[5],[6]
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20	0
Domestic Plan [Member] | Pension Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	[5],[6]
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,111	999		$ 1,043
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		483	512
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		149	89
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		632	601
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		43	10
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		43	10
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		45	25
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		45	25
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		60	36
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		60	36
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		9	6
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		9	6
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		37	37
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		37	37
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		416	389
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		416	389
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		22	15
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		22	15
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 0	0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			$ 83
Percentage of Investment Funds Comprised Of Equity Securitites		60.00%	54.00%
Percentage of Investment Funds Comprised Of Debt Securities		40.00%	46.00%
Percentage Of Investment Funds Invested in United States Securities		57.00%	39.00%
Percentage Of Investment Funds Invested In International Securities		43.00%	61.00%
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			$ 83
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			0
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member] | Limited Partnership Interests [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 0
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2,761	2,525
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,019	920	[6]
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		63	61	[7]
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			999
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | PacifiCorp [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	416	337
Domestic Plan [Member] | Pension Plan [Member] | Accounting Standards Update 2015-07 [Member] | PacifiCorp [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	$ 63	$ 61
[1]	Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.
[2]	Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 68% and 32%, respectively, for 2017 and 63% and 37%, respectively, for 2016. Additionally, these funds are invested in United States and international securities of approximately 73% and 27%, respectively, for 2017 and 72% and 28%, respectively, for 2016.
[3]	Investment funds are substantially comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 60% and 40% respectively, for 2017 and 54% and 46%, respectively, for 2016, and are invested in United States and international securities of approximately 57% and 43%, respectively, for 2017 and 39% and 61%, respectively, for 2016.
[4]	Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital.
[5]	Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.
[6]	Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 62% and 38%, respectively, for both 2017 and 2016. Additionally, these funds are invested in United States and international securities of approximately 68% and 32%, respectively, for 2017 and 60% and 40%, respectively, for 2016.
[7]	Limited partnership interests include several funds that invest primarily in real estate, buyout, growth equity and venture capital.

Employee Benefit Plans - Pac236

Employee Benefit Plans - PacifiCorp - Multiemployer and Joint Trust Pension Plans (Details) - PacifiCorp [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Joint Trustee Plan, Percentage By Which Joint Trustee Plan was at Least Funded			0.00%		80.00%		80.00%
Joint Trustee Plan, Period Contributions	[1]	$ 7		$ 8		$ 8
UMWA Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plans, Withdrawal Obligation, Most Recent Estimate		115
Multiemployer Plan, Contributions by Employer	[1]	$ 0		$ 0		$ 1
Multiemployer Plans, Certified Zone Status			Red		Red		Red
[1]	PacifiCorp's and Energy West Mining Company's minimum contributions to the plans are based on the amount of wages paid to employees covered by the Local 57 Trust Fund collective bargaining agreements and the number of mining hours worked for the UMWA 1974 Pension Plan, respectively, subject to ERISA minimum funding requirements. As a result of the plan's critical status, Energy West Mining Company was required to begin paying a surcharge for hours worked on and after December 1, 2014.

Employee Benefit Plans Employee

Employee Benefit Plans Employee Benefit Plans - PacifiCorp - Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost	$ 39	$ 34	$ 35

Employee Benefit Plans - MEC -

Employee Benefit Plans - MEC - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 9	$ 9	$ 11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(40)	(41)	(45)
Defined Benefit Plan Net Amortization	(14)	(12)	(11)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(16)	(13)	(14)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	5	5	7
Defined Benefit Plan, Interest Cost	9	10	9
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(14)	(13)	(15)
Defined Benefit Plan Net Amortization	(4)	(4)	(3)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(4)	(2)	(2)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(1)	(1)	0
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(160)	(160)	(169)
Defined Benefit Plan Net Amortization	25	46	53
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	5	41	38
Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	9	10	12
Defined Benefit Plan, Interest Cost	31	34	32
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(44)	(44)	(46)
Defined Benefit Plan Net Amortization	2	2	2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(2)	2	0
Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (6)	$ (2)	$ (4)

Employee Benefit Plans - MEC239

Employee Benefit Plans - MEC - Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	$ 666	$ 662
Defined Benefit Plan, Plan Assets, Contributions by Employer	5	2
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	106	41
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(51)	(49)
Ending balance	736	666	$ 662
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	734	740
Defined Benefit Plan, Service Cost	9	9	11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	10	10
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(10)	(7)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(51)	(49)
Ending balance	721	734	740
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	15	(68)
Assets for Plan Benefits, Defined Benefit Plan	32	19
Other current liabilities	0	0
Liability, Defined Benefit Plan, Noncurrent	(17)	(87)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	15	(68)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	272	242
MidAmerican Energy Company [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	198	184
MidAmerican Energy Company [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	684
Ending balance	745	684
MidAmerican Energy Company [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	252	249
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	1
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	1	1
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	36	14
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(13)	(13)
Ending balance	277	252	249
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	233	234
Defined Benefit Plan, Service Cost	5	5	7
Defined Benefit Plan, Interest Cost	9	10	9
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	1	1
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	11	(4)
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(13)	(13)
Ending balance	246	233	234
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	31	19
Assets for Plan Benefits, Defined Benefit Plan	31	19
Other current liabilities	0	0
Liability, Defined Benefit Plan, Noncurrent	0	0
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	31	19
MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member] | Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Life Insurance, Corporate or Bank Owned, Amount	118	110
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,525	2,489
Defined Benefit Plan, Plan Assets, Contributions by Employer	64	78
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	390	163
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(203)	(194)
Ending balance	2,761	2,525	2,489
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	2,952	2,934
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	132	67
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(203)	(194)
Ending balance	3,006	2,952	2,934
Defined Benefit Plan, Accumulated Benefit Obligation	2,988	2,929
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(245)	(427)
Assets for Plan Benefits, Defined Benefit Plan	66	26
Other current liabilities	(14)	(15)
Liability, Defined Benefit Plan, Noncurrent	(297)	(438)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(245)	(427)
Domestic Plan [Member] | MidAmerican Energy Company [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	684	678
Defined Benefit Plan, Plan Assets, Contributions by Employer	7	7
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	114	57
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(60)	(58)
Ending balance	745	684	678
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	773	785
Defined Benefit Plan, Service Cost	9	10	12
Defined Benefit Plan, Interest Cost	31	34	32
Defined Benefit Plan, Contributions by Plan Participants (Deprecated 2017-01-31)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	46	2
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31)	(60)	(58)
Ending balance	799	773	$ 785
Defined Benefit Plan, Accumulated Benefit Obligation	790	764
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(54)	(89)
Assets for Plan Benefits, Defined Benefit Plan	66	26
Other current liabilities	(8)	(8)
Liability, Defined Benefit Plan, Noncurrent	(112)	(107)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	$ (54)	$ (89)

Employee Benefit Plans - MEC240

Employee Benefit Plans - MEC - Unrecognized Amounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	$ 33
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(16)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	15
MidAmerican Energy Company [Member]
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Amortization of Gains (Losses), Net	2
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(4)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	(2)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	14	$ 88
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(37)	(52)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(16)	43	$ 37
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	73	(6)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	14	(12)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(59)	6
Defined Benefit Plan, Amortization of Gains (Losses), Net	1
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(15)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	(13)
Other Postretirement Benefits Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	10	55	49
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(52)	(5)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	7	(11)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(45)	6
Other Postretirement Benefits Plan [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(26)	(12)	(12)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	21	(1)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(7)	(1)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(14)	0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	23	36
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(25)	(31)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(2)	5	6
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(11)	(5)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	4	4
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(7)	(1)
Defined Benefit Plan, Amortization of Gains (Losses), Net	1
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(5)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	(4)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	14	18	17
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(7)	(2)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	3	3
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(4)	1
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Receivables (Payables) With Affiliates [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(16)	(13)	(11)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(4)	(3)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	1	1
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(3)	(2)
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	649	775
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(3)	(7)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	642	761	741
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	94	(65)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	25	46
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(119)	20
Defined Benefit Plan, Amortization of Gains (Losses), Net	32
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	(1)	(1)
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	28
Domestic Plan [Member] | Pension Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	665	761	729
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(68)	76
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(28)	45
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(96)	32
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		(1)
Domestic Plan [Member] | Pension Plan [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(43)	(13)	(1)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	29	(11)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	1	(1)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(30)	(12)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		0
Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	(11)	15
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	1	1
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(10)	16	28
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(24)	(10)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(2)	(2)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(26)	(12)
Defined Benefit Plan, Amortization of Gains (Losses), Net	1
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net	1
Defined Benefit Plan, Amounts That Will Be Amortized from Regulatory Assets (Liabilities) and Accumulated Other Comprehensive Income Loss In Next Fiscal Year	2
Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	24	22	22
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	4	1
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(2)	(1)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	2	0
Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(41)	(12)	0
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(29)	(11)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	0	(1)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(29)	(12)
Domestic Plan [Member] | Pension Plan [Member] | MidAmerican Energy Company [Member] | Receivables (Payables) With Affiliates [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	7	6	$ 6
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	1	0
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	0	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	$ 1	$ 0

Employee Benefit Plans - MEC241

Employee Benefit Plans - MEC - Plan Assumptions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	7.10%	7.40%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%	5.00%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2,025	2,025
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	$ 0
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	0
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	4
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	$ (4)
United States Non-Union Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.57%	4.01%	4.33%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.01%	4.33%	3.93%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.73%	7.03%	7.00%
MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	7.10%	7.40%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%	5.00%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2,025	2,025
MidAmerican Energy Company [Member] | United States Non-Union Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.50%	3.90%	4.25%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.90%	4.25%	3.75%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.50%	6.75%	7.00%
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	$ 0
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	0
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	3
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	$ (3)
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	4.06%	4.43%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	2.75%	2.75%	2.75%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.06%	4.43%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.55%	6.78%	6.88%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	2.75%	2.75%	2.75%
Domestic Plan [Member] | MidAmerican Energy Company [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	4.10%	4.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	2.75%	2.75%	2.75%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.10%	4.50%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.75%	7.00%	7.25%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	2.75%	2.75%	2.75%
After-tax [Member] | MidAmerican Energy Company [Member] | United States Non-Union Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	4.81%	5.00%	5.18%

Employee Benefit Plans - MEC242

Employee Benefit Plans - MEC - Contributions and Benefit Payments (Details) $ in Millions	Dec. 31, 2017USD ($)
Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 8
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	60
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	61
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	60
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	59
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	57
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	256
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	3
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	54
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	55
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	57
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	55
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	54
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	243
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	1
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	19
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	20
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	21
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	22
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	21
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 98

Employee Benefit Plans - MEC243

Employee Benefit Plans - MEC - Asset Allocations (Details) - MidAmerican Energy Company [Member]	12 Months Ended
	Dec. 31, 2017
Minimum [Member] | Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.20	[1]
Minimum [Member] | Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.6	[1]
Minimum [Member] | Pension Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.02
Minimum [Member] | Pension Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.00
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.25	[1]
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.5	[1]
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.00
Minimum [Member] | Other Postretirement Benefits Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.00
Maximum [Member] | Pension Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.4	[1]
Maximum [Member] | Pension Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.8	[1]
Maximum [Member] | Pension Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.08
Maximum [Member] | Pension Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.05
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.45	[1]
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.80	[1]
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	0
Maximum [Member] | Other Postretirement Benefits Plan [Member] | Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage	.05
[1]	(1)For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.

Employee Benefit Plans - MEC244

Employee Benefit Plans - MEC - Fair Value Measurements (Details) - USD ($) $ in Millions		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 736		$ 666		$ 662
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		443		411
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		115		95
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		14		20
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		11		18	[1]
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		3		2	[1]
Other Postretirement Benefits Plan [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20		19
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		20		19
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		36		29
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		36		29
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		46		39
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		46		39
Other Postretirement Benefits Plan [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		29		25
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		29		25
Other Postretirement Benefits Plan [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		185		217
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		185		217	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1]
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		8		5
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		8		5	[1]
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 220		$ 152
Percentage of Investment Funds Comprised Of Equity Securitites		68.00%		63.00%
Percentage of Investment Funds Comprised Of Debt Securities		32.00%		37.00%
Percentage Of Investment Funds Invested in United States Securities		73.00%		72.00%
Percentage Of Investment Funds Invested In International Securities		27.00%		28.00%
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 219		$ 152
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1		0
Other Postretirement Benefits Plan [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0	[1],[2]
Other Postretirement Benefits Plan [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		558		506
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		736		666
Other Postretirement Benefits Plan [Member] | Accounting Standards Update 2015-07 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		174		156	[2]
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		277		252		$ 249
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		207		193
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		70		59
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		6		10
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		6		10
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		5		5
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		5		5
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		14		11
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		14		11
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		44		37
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		44		37
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		12		11
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		12		11
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		84		122
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		84		122
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	$ 112		$ 56
Percentage of Investment Funds Comprised Of Equity Securitites		81.00%		70.00%
Percentage of Investment Funds Comprised Of Debt Securities		19.00%		30.00%
Percentage Of Investment Funds Invested in United States Securities		42.00%		30.00%
Percentage Of Investment Funds Invested In International Securities		58.00%		70.00%
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	$ 112		$ 56
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	0		0
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	0		0
Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		745		684
Pension Plan [Member] | MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		276		241
Pension Plan [Member] | MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		116		98
Pension Plan [Member] | MidAmerican Energy Company [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		17		17
Pension Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		17		17
Pension Plan [Member] | MidAmerican Energy Company [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		21		9
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		21		9
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		59		53
Pension Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		59		53
Pension Plan [Member] | MidAmerican Energy Company [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		7		6
Pension Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		7		6
Pension Plan [Member] | MidAmerican Energy Company [Member] | Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		33		22
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		33		22
Pension Plan [Member] | MidAmerican Energy Company [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		137		130
Pension Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		137		130
Pension Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Domestic Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Foreign Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		44		39
Pension Plan [Member] | MidAmerican Energy Company [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		44		39
Pension Plan [Member] | MidAmerican Energy Company [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Foreign Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	$ 74		$ 63
Percentage of Investment Funds Comprised Of Equity Securitites		69.00%		74.00%
Percentage of Investment Funds Comprised Of Debt Securities		31.00%		26.00%
Percentage Of Investment Funds Invested in United States Securities		72.00%		71.00%
Percentage Of Investment Funds Invested In International Securities		28.00%		29.00%
Pension Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	$ 74		$ 63
Pension Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Pension Plan [Member] | MidAmerican Energy Company [Member] | Plan Asset Categories Excluding Investments Measured with a NAV excluding the Practical Expedient [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		392		339
Pension Plan [Member] | MidAmerican Energy Company [Member] | Accounting Standards Update 2015-07 [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		315	[5]	295	[4]
Pension Plan [Member] | MidAmerican Energy Company [Member] | Accounting Standards Update 2015-07 [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 38		$ 50
[1]	Refer to Note 15 for additional discussion regarding the three levels of the fair value hierarchy.
[2]	Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 68% and 32%, respectively, for 2017 and 63% and 37%, respectively, for 2016. Additionally, these funds are invested in United States and international securities of approximately 73% and 27%, respectively, for 2017 and 72% and 28%, respectively, for 2016.
[3]	(2)Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 81% and 19%, respectively, for 2017 and 70% and 30%, respectively, for 2016. Additionally, these funds are invested in United States and international securities of approximately 42% and 58%, respectively, for 2017 and 30% and 70%, respectively, for 2016.
[4]	(2)Investment funds are comprised of mutual funds and collective trust funds. These funds consist of equity and debt securities of approximately 69% and 31%, respectively, for 2017 and 74% and 26%, respectively, for 2016. Additionally, these funds are invested in United States and international securities of approximately 72% and 28%, respectively, for 2017 and 71% and 29%, respectively, for 2016.
[5]	(1)For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.

Employee Benefit Plans - MEC245

Employee Benefit Plans - MEC - Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost	$ 20	$ 20	$ 20

Employee Benefit Plans - MidAme

Employee Benefit Plans - MidAmerican Funding - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 4	$ 4	$ 4
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(16)	(13)	(14)
Other Postretirement Benefits Plan [Member] | MidAmerican Funding, LLC and Subsidiaries [Domain]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (3)	$ (1)	$ (2)

Retirement Plan and Postreti247

Retirement Plan and Postretirement Benefits - NPC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Noncurrent	$ 17	$ 87
Liability, Defined Benefit Plan, Current	0	0
Defined Benefit Plan, Plan Assets, Contributions by Employer	5	2
Nevada Power Company [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	0	0	$ 0
Nevada Power Company [Member] | NV Energy, Inc. [Member] | Other Noncurrent Liabilities [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Noncurrent	1	4
Qualified Plan [Member] | Nevada Power Company [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	36	0
Qualified Plan [Member] | Nevada Power Company [Member] | NV Energy, Inc. [Member] | Other Noncurrent Liabilities [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Noncurrent	23	24
Nonqualified Plan [Member] | Nevada Power Company [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	1		$ 0
Nonqualified Plan [Member] | Nevada Power Company [Member] | NV Energy, Inc. [Member] | Other Noncurrent Liabilities [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Noncurrent	10	9
Nonqualified Plan [Member] | Nevada Power Company [Member] | NV Energy, Inc. [Member] | Other Current Liabilities [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Current	$ 1	$ 1

Retirement Plan and Postreti248

Retirement Plan and Postretirement Benefits - SPPC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 5	$ 2
Liability, Defined Benefit Plan, Noncurrent	(17)	(87)
Other current liabilities	0	0
Sierra Pacific Power Company [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	4	1	$ 0
Sierra Pacific Power Company [Member] | Other Noncurrent Liabilities [Member] | NV Energy, Inc. [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Noncurrent	(20)	(28)
Qualified Plan [Member] | Sierra Pacific Power Company [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	27	0
Qualified Plan [Member] | Sierra Pacific Power Company [Member] | Other Noncurrent Liabilities [Member] | NV Energy, Inc. [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Noncurrent	(2)	(12)
Nonqualified Plan [Member] | Sierra Pacific Power Company [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	1	0	$ 0
Nonqualified Plan [Member] | Sierra Pacific Power Company [Member] | Other Noncurrent Liabilities [Member] | NV Energy, Inc. [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Liability, Defined Benefit Plan, Noncurrent	(8)	(9)
Nonqualified Plan [Member] | Sierra Pacific Power Company [Member] | Other Current Liabilities [Member] | NV Energy, Inc. [Member] | Other Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other current liabilities	$ (1)	$ (1)

Asset Retirement Obligations -

Asset Retirement Obligations - Asset Retirement Obligation By Type (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		$ 954	$ 954	$ 921
Regulatory Liabilities		7,511	3,120
Fossil Fuel Plant [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		380	404
Quad Cities Station [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		342	343
Wind Generating Facility [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		138	124
Offshore pipeline facilities [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		32	33
Solar Generating Facility [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		19	12
Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		43	38
Removal Costs [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities	[1]	2,349	2,242
Quad Cities Station nuclear decommissioning trust funds [Member]
Asset Retirement Obligations By Type [Line Items]
Nuclear decommissioning trust funds		$ 515	$ 460
[1]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

Asset Retirement Obligations250

Asset Retirement Obligations - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 954	$ 921
Asset Retirement Obligation, Revision of Estimate	(18)	33
Asset Retirement Obligation, Liabilities Incurred	21	25
Retirements	(45)	(63)
Asset Retirement Obligation, Accretion Expense	42	38
Asset Retirement Obligation	954	921	$ 954	$ 954
Asset Retirement Obligation, Current			60	98
Asset Retirement Obligations, Noncurrent			$ 894	$ 856
Ending Balance	$ 954	$ 954

Asset Retirement Obligations251

Asset Retirement Obligations - PacifiCorp - Asset Retirement Obligations By Type (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligations By Type [Line Items]
Regulatory liabilities	$ 7,309	$ 2,933
PacifiCorp [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory liabilities	2,996	978
PacifiCorp [Member] | Removal Costs [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory liabilities	$ 955	$ 917

Asset Retirement Obligations252

Asset Retirement Obligations - PacifiCorp - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 954	$ 921
Asset Retirement Obligation, Revision of Estimate	(18)	33
Asset Retirement Obligation, Liabilities Incurred	21	25
Retirements	(45)	(63)
Asset Retirement Obligation, Accretion Expense	42	38
Asset Retirement Obligation, Current	60	98
Asset Retirement Obligations, Noncurrent	894	856
Ending Balance	954	954
PacifiCorp [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	215	224
Asset Retirement Obligation, Revision of Estimate	(8)	2
Asset Retirement Obligation, Liabilities Incurred	6	0
Retirements	(6)	(19)
Asset Retirement Obligation, Accretion Expense	8	8
Asset Retirement Obligation, Current	25	21
Asset Retirement Obligations, Noncurrent	190	194
Ending Balance	$ 215	$ 215

Asset Retirement Obligations253

Asset Retirement Obligations - MEC - Asset Retirement Obligations By Type (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		$ 954	$ 954	$ 921
Regulatory Liabilities		7,511	3,120
Quad Cities Unit Nos 1 and 2 [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		342	343
Fossil Fuel Plant [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		380	404
Wind Generating Facility [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		138	124
Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		43	38
MidAmerican Energy Company [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		559	567	$ 532
Decommissioning Fund Investments, Fair Value		515	460
MidAmerican Energy Company [Member] | Quad Cities Unit Nos 1 and 2 [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		342	343
MidAmerican Energy Company [Member] | Fossil Fuel Plant [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		113	132
MidAmerican Energy Company [Member] | Wind Generating Facility [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		103	91
MidAmerican Energy Company [Member] | Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		1	1
Quad Cities Unit Nos 1 and 2 [Member] | MidAmerican Energy Company [Member]
Asset Retirement Obligations By Type [Line Items]
Decommissioning Fund Investments, Fair Value		515	460
Removal Costs [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities	[1]	2,349	2,242
Removal Costs [Member] | MidAmerican Energy Company [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities		$ 688	$ 665
[1]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

Asset Retirement Obligations254

Asset Retirement Obligations - MEC - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 954	$ 921
Asset Retirement Obligation, Revision of Estimate	(18)	33
Asset Retirement Obligation, Liabilities Incurred	21	25
Asset Retirement Obligation, Liabilities Settled	(45)	(63)
Asset Retirement Obligation, Accretion Expense	42	38
Asset Retirement Obligation, Current	60	98
Asset Retirement Obligations, Noncurrent	894	856
Ending Balance	954	954
MidAmerican Energy Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	567	532
Asset Retirement Obligation, Revision of Estimate	(14)	28
Asset Retirement Obligation, Liabilities Incurred	8	14
Asset Retirement Obligation, Liabilities Settled	(26)	(32)
Asset Retirement Obligation, Accretion Expense	24	25
Asset Retirement Obligation, Current	31	57
Asset Retirement Obligations, Noncurrent	528	510
Ending Balance	$ 559	$ 567

Asset Retirement Obligations255

Asset Retirement Obligations - NPC - Asset Retirement Obligation by Type (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities		$ 7,511	$ 3,120
Asset Retirement Obligation		954	954	$ 921
Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		43	38
Removal Costs [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities	[1]	2,349	2,242
Nevada Power Company [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities		1,121	453
Asset Retirement Obligation		80	83	$ 85
Nevada Power Company [Member] | Waste water remediation [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		39	38
Nevada Power Company [Member] | Evaporative Ponds and Dry Ash Landfills [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		11	22
Nevada Power Company [Member] | Asbestos [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		3	4
Nevada Power Company [Member] | Solar [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		3	2
Nevada Power Company [Member] | Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		24	17
Nevada Power Company [Member] | Removal Costs [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities	[2]	$ 307	$ 294
[1]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.
[2]	(2)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

Asset Retirement Obligations As

Asset Retirement Obligations Asset Retirement Obligations - NPC - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 954	$ 921
Asset Retirement Obligation, Revision of Estimate	(18)	33
Retirements	(45)	(63)
Asset Retirement Obligation, Accretion Expense	42	38
Ending Balance	954	954
Asset Retirement Obligation, Current	60	98
Asset Retirement Obligations, Noncurrent	894	856
Nevada Power Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	83	85
Asset Retirement Obligation, Revision of Estimate	6	4
Retirements	(13)	(10)
Asset Retirement Obligation, Accretion Expense	4	4
Ending Balance	80	83
Asset Retirement Obligation, Current	4	20
Asset Retirement Obligations, Noncurrent	$ 76	$ 63

Asset Retirement Obligations257

Asset Retirement Obligations - SPPC - Asset Retirement Obligation by Type (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities		$ 7,511	$ 3,120
Asset Retirement Obligation		954	954	$ 921
Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		43	38
Removal Costs [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities	[1]	2,349	2,242
Sierra Pacific Power Company [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities		500	290
Asset Retirement Obligation		10	10	$ 10
Sierra Pacific Power Company [Member] | Asbestos [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		5	4
Sierra Pacific Power Company [Member] | Evaporative Ponds and Dry Ash Landfills [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		2	3
Sierra Pacific Power Company [Member] | Other Plant in Service [Member]
Asset Retirement Obligations By Type [Line Items]
Asset Retirement Obligation		3	3
Sierra Pacific Power Company [Member] | Removal Costs [Member]
Asset Retirement Obligations By Type [Line Items]
Regulatory Liabilities		$ 211	$ 205
[1]	Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

Asset Retirement Obligations258

Asset Retirement Obligations - SPPC - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 954	$ 921
Retirements	(45)	(63)
Ending Balance	954	954
Asset Retirement Obligation, Current	60	98
Asset Retirement Obligations, Noncurrent	894	856
Sierra Pacific Power Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	10	10
Retirements	0	0
Ending Balance	10	10
Asset Retirement Obligation, Current	0	0
Asset Retirement Obligations, Noncurrent	$ 10	$ 10

Commitments and Contingencies -

Commitments and Contingencies - Commitments Table (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)number_of_projects	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Contractual Obligation [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 180
Operating Leases, Future Minimum Payments, Due in Two Years	157
Operating Leases, Future Minimum Payments, Due in Three Years	141
Operating Leases, Future Minimum Payments, Due in Four Years	121
Operating Leases, Future Minimum Payments, Due in Five Years	111
Operating Leases, Future Minimum Payments, Due Thereafter	1,297
Operating Leases, Future Minimum Payments Due	2,007
Contractual Obligation, Due in Next Twelve Months	3,644
Contractual Obligation, Due in Second Year	2,100
Contractual Obligation, Due in Third Year	1,819
Contractual Obligation, Due in Fourth Year	1,562
Contractual Obligation, Due in Fifth Year	1,419
Contractual Obligation, Due after Fifth Year	12,396
Contractual Obligation	22,940
Operating Leases, Rent Expense	156	$ 156	$ 146
MidAmerican Funding [Member]
Contractual Obligation [Line Items]
Coal transportation costs, railroad	$ 109	$ 137	$ 185
Number of Construction Projects | number_of_projects	4
Fuel, capacity and transmission contract commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	$ 2,098
Purchase Obligation, Due in Second Year	1,637
Purchase Obligation, Due in Third Year	1,435
Purchase Obligation, Due in Fourth Year	1,210
Purchase Obligation, Due in Fifth Year	1,055
Purchase Obligation, Due after Fifth Year	10,044
Purchase Obligation	17,479
Capital Addition Purchase Commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	1,120
Purchase Obligation, Due in Second Year	57
Purchase Obligation, Due in Third Year	5
Purchase Obligation, Due in Fourth Year	0
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	1,182
Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	246
Purchase Obligation, Due in Second Year	249
Purchase Obligation, Due in Third Year	238
Purchase Obligation, Due in Fourth Year	231
Purchase Obligation, Due in Fifth Year	253
Purchase Obligation, Due after Fifth Year	1,055
Purchase Obligation	$ 2,272

Commitments and Contingencies _

Commitments and Contingencies – Hydroelectric (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Hydroelectric [Line Items]
Operating Leases, Rent Expense	$ 156,000,000	$ 156,000,000	$ 146,000,000
PacifiCorp [Member]
Hydroelectric [Line Items]
Capital expenditures required by hydroelectric licenses	239,000,000
PacifiCorp [Member] | Klamath Hydroelectric System [Member]
Hydroelectric [Line Items]
Dam removal cost limit	200,000,000
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | OREGON
Hydroelectric [Line Items]
Dam removal cost limit	184,000,000
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | CALIFORNIA
Hydroelectric [Line Items]
Dam removal cost limit	16,000,000
Additional dam removal costs, California bond measure	250,000,000
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | VARIOUS [Domain]
Hydroelectric [Line Items]
Klamath Relicensing and Settlement Costs	55,000,000
PacifiCorp [Member]
Hydroelectric [Line Items]
Capital expenditures required by hydroelectric licenses	239,000,000
PacifiCorp [Member] | Klamath Hydroelectric System [Member]
Hydroelectric [Line Items]
Dam removal cost limit	200,000,000
Public Utilities Property Plant & Equipment, Number of Generating Facilities	4
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | OREGON
Hydroelectric [Line Items]
Dam removal cost limit	184,000,000
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | CALIFORNIA
Hydroelectric [Line Items]
Dam removal cost limit	16,000,000
Additional dam removal costs, California bond measure	$ 250,000,000

Commitments and Contingencie261

Commitments and Contingencies - PacifiCorp - Hydroelectric (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Hydroelectric [Line Items]
Assets	$ 90,208	$ 85,440	$ 83,618
PacifiCorp [Member]
Hydroelectric [Line Items]
Assets	21,920	$ 22,394
Capital expenditures required by hydroelectric licenses	239
PacifiCorp [Member] | Klamath Hydroelectric System [Member]
Hydroelectric [Line Items]
Dam removal cost limit	200
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | OREGON
Hydroelectric [Line Items]
Dam removal cost limit	184
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | CALIFORNIA
Hydroelectric [Line Items]
Dam removal cost limit	16
Additional dam removal costs, California bond measure	250
PacifiCorp [Member] | Klamath Hydroelectric System [Member] | VARIOUS [Domain]
Hydroelectric [Line Items]
Klamath Relicensing and Settlement Costs	$ 55

Commitments and Contingencie262

Commitments and Contingencies - PacifiCorp - Commitments Tables (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Contractual Obligation [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 180
Operating Leases, Future Minimum Payments, Due in Two Years	157
Operating Leases, Future Minimum Payments, Due in Three Years	141
Operating Leases, Future Minimum Payments, Due in Four Years	121
Operating Leases, Future Minimum Payments, Due in Five Years	111
Operating Leases, Future Minimum Payments, Due Thereafter	1,297
Operating Leases, Future Minimum Payments Due	2,007
Contractual Obligation, Due in Next Twelve Months	3,644
Contractual Obligation, Due in Second Year	2,100
Contractual Obligation, Due in Third Year	1,819
Contractual Obligation, Due in Fourth Year	1,562
Contractual Obligation, Due in Fifth Year	1,419
Contractual Obligation, Due after Fifth Year	12,396
Contractual Obligation	22,940
Capital Addition Purchase Commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	1,120
Purchase Obligation, Due in Second Year	57
Purchase Obligation, Due in Third Year	5
Purchase Obligation, Due in Fourth Year	0
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	1,182
Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	246
Purchase Obligation, Due in Second Year	249
Purchase Obligation, Due in Third Year	238
Purchase Obligation, Due in Fourth Year	231
Purchase Obligation, Due in Fifth Year	253
Purchase Obligation, Due after Fifth Year	1,055
Purchase Obligation	2,272
PacifiCorp [Member]
Contractual Obligation [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	7
Operating Leases, Future Minimum Payments, Due in Two Years	7
Operating Leases, Future Minimum Payments, Due in Three Years	7
Operating Leases, Future Minimum Payments, Due in Four Years	7
Operating Leases, Future Minimum Payments, Due in Five Years	6
Operating Leases, Future Minimum Payments, Due Thereafter	97
Operating Leases, Future Minimum Payments Due	131
Contractual Obligation, Due in Next Twelve Months	1,220
Contractual Obligation, Due in Second Year	968
Contractual Obligation, Due in Third Year	876
Contractual Obligation, Due in Fourth Year	710
Contractual Obligation, Due in Fifth Year	568
Contractual Obligation, Due after Fifth Year	3,898
Contractual Obligation	8,240
Rent expense for power purchase agreements meeting definition of operating lease	$ 14	$ 14	$ 13
Maximum percentage of energy sources for which a share of operating costs and debt service is required	5.00%	5.00%	5.00%
Operating leases, rent expense, net	$ 15	$ 15
PacifiCorp [Member] | Purchased electricity contracts - commercially operable
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	276
Purchase Obligation, Due in Second Year	165
Purchase Obligation, Due in Third Year	161
Purchase Obligation, Due in Fourth Year	150
Purchase Obligation, Due in Fifth Year	145
Purchase Obligation, Due after Fifth Year	1,574
Purchase Obligation	2,471
PacifiCorp [Member] | Purchased electricity contracts - not commercially operable
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	9
Purchase Obligation, Due in Second Year	18
Purchase Obligation, Due in Third Year	26
Purchase Obligation, Due in Fourth Year	26
Purchase Obligation, Due in Fifth Year	27
Purchase Obligation, Due after Fifth Year	451
Purchase Obligation	557
PacifiCorp [Member] | Fuel contracts
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	695
Purchase Obligation, Due in Second Year	619
Purchase Obligation, Due in Third Year	591
Purchase Obligation, Due in Fourth Year	453
Purchase Obligation, Due in Fifth Year	337
Purchase Obligation, Due after Fifth Year	1,268
Purchase Obligation	3,963
PacifiCorp [Member] | Capital Addition Purchase Commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	85
Purchase Obligation, Due in Second Year	29
Purchase Obligation, Due in Third Year	3
Purchase Obligation, Due in Fourth Year	0
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	117
PacifiCorp [Member] | Transmission
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	112
Purchase Obligation, Due in Second Year	96
Purchase Obligation, Due in Third Year	66
Purchase Obligation, Due in Fourth Year	49
Purchase Obligation, Due in Fifth Year	39
Purchase Obligation, Due after Fifth Year	428
Purchase Obligation	790
PacifiCorp [Member] | Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	36
Purchase Obligation, Due in Second Year	34
Purchase Obligation, Due in Third Year	22
Purchase Obligation, Due in Fourth Year	25
Purchase Obligation, Due in Fifth Year	14
Purchase Obligation, Due after Fifth Year	80
Purchase Obligation	$ 211

Commitments and Contingencie263

Commitments and Contingencies - MEC - Commitments Table (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)number_of_projects	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Contractual Obligation [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 180
Operating Leases, Future Minimum Payments, Due in Two Years	157
Operating Leases, Future Minimum Payments, Due in Three Years	141
Operating Leases, Future Minimum Payments, Due in Four Years	121
Operating Leases, Future Minimum Payments, Due in Five Years	111
Operating Leases, Future Minimum Payments, Due Thereafter	1,297
Operating Leases, Future Minimum Payments Due	2,007
Contractual Obligation, Due in Next Twelve Months	3,644
Contractual Obligation, Due in Second Year	2,100
Contractual Obligation, Due in Third Year	1,819
Contractual Obligation, Due in Fourth Year	1,562
Contractual Obligation, Due in Fifth Year	1,419
Contractual Obligation, Due after Fifth Year	12,396
Contractual Obligation	22,940
Capital Addition Purchase Commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	1,120
Purchase Obligation, Due in Second Year	57
Purchase Obligation, Due in Third Year	5
Purchase Obligation, Due in Fourth Year	0
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	1,182
Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	246
Purchase Obligation, Due in Second Year	249
Purchase Obligation, Due in Third Year	238
Purchase Obligation, Due in Fourth Year	231
Purchase Obligation, Due in Fifth Year	253
Purchase Obligation, Due after Fifth Year	1,055
Purchase Obligation	2,272
MidAmerican Energy Company [Member]
Contractual Obligation [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	22
Operating Leases, Future Minimum Payments, Due in Two Years	21
Operating Leases, Future Minimum Payments, Due in Three Years	21
Operating Leases, Future Minimum Payments, Due in Four Years	21
Operating Leases, Future Minimum Payments, Due in Five Years	21
Operating Leases, Future Minimum Payments, Due Thereafter	713
Operating Leases, Future Minimum Payments Due	819
Contractual Obligation, Due in Next Twelve Months	1,176
Contractual Obligation, Due in Second Year	313
Contractual Obligation, Due in Third Year	258
Contractual Obligation, Due in Fourth Year	228
Contractual Obligation, Due in Fifth Year	241
Contractual Obligation, Due after Fifth Year	1,031
Contractual Obligation	$ 3,247
Number of Construction Projects | number_of_projects	4
Operating leases, rent expense, net	$ 3	$ 4	$ 4
MidAmerican Energy Company [Member] | Fuel contracts
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	112
Purchase Obligation, Due in Second Year	56
Purchase Obligation, Due in Third Year	12
Purchase Obligation, Due in Fourth Year	9
Purchase Obligation, Due in Fifth Year	8
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	197
MidAmerican Energy Company [Member] | Electric capacity and transmission
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	34
Purchase Obligation, Due in Second Year	31
Purchase Obligation, Due in Third Year	31
Purchase Obligation, Due in Fourth Year	27
Purchase Obligation, Due in Fifth Year	16
Purchase Obligation, Due after Fifth Year	43
Purchase Obligation	182
MidAmerican Energy Company [Member] | Natural gas contracts for gas operations
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	122
Purchase Obligation, Due in Second Year	75
Purchase Obligation, Due in Third Year	73
Purchase Obligation, Due in Fourth Year	57
Purchase Obligation, Due in Fifth Year	42
Purchase Obligation, Due after Fifth Year	42
Purchase Obligation	411
MidAmerican Energy Company [Member] | Capital Addition Purchase Commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	790
Purchase Obligation, Due in Second Year	28
Purchase Obligation, Due in Third Year	2
Purchase Obligation, Due in Fourth Year	0
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	0
Purchase Obligation	820
MidAmerican Energy Company [Member] | Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	96
Purchase Obligation, Due in Second Year	102
Purchase Obligation, Due in Third Year	119
Purchase Obligation, Due in Fourth Year	114
Purchase Obligation, Due in Fifth Year	154
Purchase Obligation, Due after Fifth Year	233
Purchase Obligation	$ 818

Commitments and Contingencies C

Commitments and Contingencies Commitments and Contingencies - MEC - Transmission Rates (Details) - MidAmerican Energy Company [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual	$ 9
Electric Transmission [Member]
Loss Contingencies [Line Items]
Public Utilities, Approved Return on Equity Adder, Percentage	0.50%
Electric Transmission [Member] | Prior to September 2016 [Member]
Loss Contingencies [Line Items]
Public Utilities, Approved Return on Equity, Percentage	12.38%
Electric Transmission [Member] | November 2013 to February 2015 [Member]
Loss Contingencies [Line Items]
Public Utilities, Approved Return on Equity, Percentage	10.32%
Public Utilities, Intervenor Proposed Return On Equity, Percentage	9.15%
Electric Transmission [Member] | February 2015 through May 2016 [Member]
Loss Contingencies [Line Items]
Public Utilities, Intervenor Proposed Return On Equity, Percentage	8.67%

Commitments and Contingencie265

Commitments and Contingencies - NPC - Legal (Details) - Nevada Power Company [Member]	1 Months Ended		12 Months Ended
	Apr. 30, 2017MW	Mar. 31, 2017MW	Dec. 31, 2017MW	Dec. 31, 2016MW	Dec. 31, 2015power_purchase_agreementsMW	Dec. 31, 2014MW
Loss Contingencies [Line Items]
Number of Approved Renewable Power Purchase Agreements | power_purchase_agreements					2
300 Megawatts of Coal Energy [Member]
Loss Contingencies [Line Items]
Coal-Fired Power Plant Capacity						300
257 Megawatts of Coal Energy [Member]
Loss Contingencies [Line Items]
Coal-Fired Power Plant Capacity		257
812 Megawatts of Coal Energy [Member]
Loss Contingencies [Line Items]
Coal-Fired Power Plant Capacity			812
272 Megawatts of Renewable Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity						272
210 Megawatts of Renewable Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity						210
15 Megawatts of Solar Renewable Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity					15
100 Megawatts of Renewable Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity					100
100 Megawatts of Solar Renewable Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity				100
130 Megawatts of Natural Gas Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity	130
Ownership Percentage Acquired	25.00%
54 Megawatts of Natural Gas Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity	54
35 Megawatts of Renewable Energy [Member]
Loss Contingencies [Line Items]
New Generation Capacity			35

Commitments and Contingencie266

Commitments and Contingencies - NPC - Commitments Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Contractual Obligation [Line Items]
Contractual Obligation, Due in Next Twelve Months	$ 3,644
Contractual Obligation, Due in Second Year	2,100
Contractual Obligation, Due in Third Year	1,819
Contractual Obligation, Due in Fourth Year	1,562
Contractual Obligation, Due in Fifth Year	1,419
Contractual Obligation, Due after Fifth Year	12,396
Contractual Obligation	22,940
Fuel, capacity and transmission contract commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	2,098
Purchase Obligation, Due in Second Year	1,637
Purchase Obligation, Due in Third Year	1,435
Purchase Obligation, Due in Fourth Year	1,210
Purchase Obligation, Due in Fifth Year	1,055
Purchase Obligation, Due after Fifth Year	10,044
Purchase Obligation	17,479
Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	246
Purchase Obligation, Due in Second Year	249
Purchase Obligation, Due in Third Year	238
Purchase Obligation, Due in Fourth Year	231
Purchase Obligation, Due in Fifth Year	253
Purchase Obligation, Due after Fifth Year	1,055
Purchase Obligation	2,272
Nevada Power Company [Member]
Contractual Obligation [Line Items]
Contractual Obligation, Due in Next Twelve Months	644
Contractual Obligation, Due in Second Year	516
Contractual Obligation, Due in Third Year	450
Contractual Obligation, Due in Fourth Year	449
Contractual Obligation, Due in Fifth Year	449
Contractual Obligation, Due after Fifth Year	5,723
Contractual Obligation	8,231
Rent expense for power purchase agreements meeting definition of operating lease	310	$ 302	$ 264
Operating Lease and Easement, Expense	9	$ 13	$ 11
Nevada Power Company [Member] | Fuel, capacity and transmission contract commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	591
Purchase Obligation, Due in Second Year	450
Purchase Obligation, Due in Third Year	377
Purchase Obligation, Due in Fourth Year	378
Purchase Obligation, Due in Fifth Year	380
Purchase Obligation, Due after Fifth Year	5,208
Purchase Obligation	7,384
Nevada Power Company [Member] | Fuel, capacity and transmission contract commitments, Not commercially operable [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	0
Purchase Obligation, Due in Second Year	15
Purchase Obligation, Due in Third Year	22
Purchase Obligation, Due in Fourth Year	24
Purchase Obligation, Due in Fifth Year	25
Purchase Obligation, Due after Fifth Year	421
Purchase Obligation	507
Nevada Power Company [Member] | Operating Leases and easements [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	7
Purchase Obligation, Due in Second Year	7
Purchase Obligation, Due in Third Year	8
Purchase Obligation, Due in Fourth Year	8
Purchase Obligation, Due in Fifth Year	7
Purchase Obligation, Due after Fifth Year	54
Purchase Obligation	91
Nevada Power Company [Member] | Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	46
Purchase Obligation, Due in Second Year	44
Purchase Obligation, Due in Third Year	43
Purchase Obligation, Due in Fourth Year	39
Purchase Obligation, Due in Fifth Year	37
Purchase Obligation, Due after Fifth Year	40
Purchase Obligation	$ 249

Commitments and Contingencie267

Commitments and Contingencies - SPPC - Commitments Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Contractual Obligation [Line Items]
Contractual Obligation, Due in Next Twelve Months	$ 3,644
Contractual Obligation, Due in Second Year	2,100
Contractual Obligation, Due in Third Year	1,819
Contractual Obligation, Due in Fourth Year	1,562
Contractual Obligation, Due in Fifth Year	1,419
Contractual Obligation, Due after Fifth Year	12,396
Contractual Obligation	22,940
Fuel, capacity and transmission contract commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	2,098
Purchase Obligation, Due in Second Year	1,637
Purchase Obligation, Due in Third Year	1,435
Purchase Obligation, Due in Fourth Year	1,210
Purchase Obligation, Due in Fifth Year	1,055
Purchase Obligation, Due after Fifth Year	10,044
Purchase Obligation	17,479
Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	246
Purchase Obligation, Due in Second Year	249
Purchase Obligation, Due in Third Year	238
Purchase Obligation, Due in Fourth Year	231
Purchase Obligation, Due in Fifth Year	253
Purchase Obligation, Due after Fifth Year	1,055
Purchase Obligation	2,272
Sierra Pacific Power Company [Member]
Contractual Obligation [Line Items]
Contractual Obligation, Due in Next Twelve Months	210
Contractual Obligation, Due in Second Year	172
Contractual Obligation, Due in Third Year	141
Contractual Obligation, Due in Fourth Year	106
Contractual Obligation, Due in Fifth Year	100
Contractual Obligation, Due after Fifth Year	1,171
Contractual Obligation	1,900
Rent expense for power purchase agreements meeting definition of operating lease	74	$ 69	$ 65
Operating Lease and Easement, Expense	4	$ 6	$ 7
Sierra Pacific Power Company [Member] | Fuel, capacity and transmission contract commitments [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	200
Purchase Obligation, Due in Second Year	155
Purchase Obligation, Due in Third Year	114
Purchase Obligation, Due in Fourth Year	74
Purchase Obligation, Due in Fifth Year	71
Purchase Obligation, Due after Fifth Year	515
Purchase Obligation	1,129
Sierra Pacific Power Company [Member] | Fuel, capacity and transmission contract commitments, Not commercially operable [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	0
Purchase Obligation, Due in Second Year	7
Purchase Obligation, Due in Third Year	17
Purchase Obligation, Due in Fourth Year	22
Purchase Obligation, Due in Fifth Year	22
Purchase Obligation, Due after Fifth Year	590
Purchase Obligation	658
Sierra Pacific Power Company [Member] | Operating Leases, Easements, Maintenance and Service [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	4
Purchase Obligation, Due in Second Year	4
Purchase Obligation, Due in Third Year	4
Purchase Obligation, Due in Fourth Year	3
Purchase Obligation, Due in Fifth Year	2
Purchase Obligation, Due after Fifth Year	54
Purchase Obligation	71
Sierra Pacific Power Company [Member] | Maintenance, service and other contracts [Member]
Contractual Obligation [Line Items]
Purchase Obligation, Due in Next Twelve Months	6
Purchase Obligation, Due in Second Year	6
Purchase Obligation, Due in Third Year	6
Purchase Obligation, Due in Fourth Year	7
Purchase Obligation, Due in Fifth Year	5
Purchase Obligation, Due after Fifth Year	12
Purchase Obligation	$ 42

Preferred Stock - PacifiCorp (D

Preferred Stock - PacifiCorp (Details) - PacifiCorp [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2017Payments$ / sharesshares	Dec. 31, 2016$ / sharesshares
Class of Stock [Line Items]
Number Of Full Quarterly Dividend Payments In Default Before Preferred Stockholders Elect Board Of Directors | Payments	4
Preferred Stock Class, 5 Percent Preferred [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	127	127
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Dividend Rate, Percentage	5.00%	5.00%
Preferred Stock Class, Serial Preferred [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	3,500	3,500
Preferred Stock, Par or Stated Value Per Share | $ / shares	$ 100	$ 100
Preferred Stock, Shares Issued	24	24
Preferred Stock, Shares Outstanding	24	24
Preferred Stock Class, No Par Serial Preferred [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	16,000	16,000
Shares Issued for Certain Class of Preferred Stock	0	0
Shares Outstanding for Certain Class of Preferred Stock	0	0
Minimum [Member] | Preferred Stock Class, Serial Preferred [Member]
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage	6.00%	6.00%
Maximum [Member] | Preferred Stock Class, Serial Preferred [Member]
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage	7.00%	7.00%

BHE Shareholders' Equity (Detai

BHE Shareholders' Equity (Details) - USD ($) $ in Millions	1 Months Ended		6 Months Ended	12 Months Ended
	Feb. 28, 2017	Feb. 28, 2015	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2016
Class of Stock [Line Items]
BHE junior subordinated debentures				$ 100		$ 944
Common stock, value, repurchased				19	$ 36
Common Stock [Member]
Class of Stock [Line Items]
Common stock repurchased (shares)	35,000	75,000
Common stock, value, repurchased	$ 19	$ 36
BHE [Member] | BHE Junior Subordinated Debentures, due June 2057 [Member]
Class of Stock [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			5.00%
Conversion of Stock, Shares Converted			181,819
Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member]
Class of Stock [Line Items]
BHE junior subordinated debentures				100		944
Junior Subordinated Debt [Member] | Berkshire Hathaway Energy [Member] | BHE Junior Subordinated Debentures, due June 2057 [Member]
Class of Stock [Line Items]
BHE junior subordinated debentures				$ 100		$ 0

BHE Shareholders' Equity - Rest

BHE Shareholders' Equity - Restricted Net Assets (Details) $ in Billions	Dec. 31, 2017USD ($)
Stockholders' Equity Note [Abstract]
BHE restricted net assets	$ 16.9
BHE's subsidiaries restricted net assets	$ 19.4

Common Shareholder's Equity - P

Common Shareholder's Equity - PacifiCorp (Details) - PacifiCorp [Member] - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Dividends, Common Stock, Cash		$ 600	$ 875	$ 950
Minimum Common Equity To Capitalization Percentage		44.00%
Percentage of preferred stock to be treated as common equity for common equity percentage calculation		50.00%
Actual common equity percentage as calculated in accordance with acquisition commitment		54.00%
Amount available for dividend distribution without prior approval		$ 2,500
Subsequent Event [Member]
Class of Stock [Line Items]
Dividends, Common Stock, Cash	$ 250

Components of Accumulated Ot272

Components of Accumulated Other Comprehensive Loss, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (1,511)
Other comprehensive (loss) income, unrecognized amounts on retirement benefits	64	$ (9)	$ 52
Other comprehensive (loss) income, foreign currency translation adjustment	546	(583)	(680)
Other comprehensive (loss) income, unrealized gains on available-for-sale securities	500	(30)	225
Other comprehensive (loss) income, unrealized gains on cash flow hedges	3	19	(11)
Other comprehensive income (loss)	1,113	(603)	(414)
Ending balance	(398)	(1,511)
Accumulated Other Comprehensive Loss, Net [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, unrecognized amounts on retirement benefits	(447)	(438)	(490)
Balance, foreign currency translation adjustment	(1,675)	(1,092)	(412)
Beginning balance	585	615	390
Beginning balance	26	7	18
Beginning balance	(1,511)	(908)	(494)
Other comprehensive (loss) income, unrecognized amounts on retirement benefits	64	(9)	52
Other comprehensive (loss) income, foreign currency translation adjustment	546	(583)	(680)
Other comprehensive (loss) income, unrealized gains on available-for-sale securities	500	(30)	225
Other comprehensive (loss) income, unrealized gains on cash flow hedges	3	19	(11)
Other comprehensive income (loss)	1,113	(603)	(414)
Balance, unrecognized amounts on retirement benefits	(383)	(447)	(438)
Balance, foreign currency translation adjustment	(1,129)	(1,675)	(1,092)
Ending balance	1,085	585	615
Ending balance	29	26	7
Ending balance	$ (398)	$ (1,511)	$ (908)

Components of Accumulated Ot273

Components of Accumulated Other Comprehensive Loss, Net - PacifiCorp (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
PacifiCorp [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	$ (15)	$ (12)

Components of Accumulated Ot274

Components of Accumulated Other Comprehensive Loss, Net - MEC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of accumulated other comprehensive income (loss)
Beginning balance	$ (1,511)
Unrealized gains (losses) on available-for-sale securities, net of tax	500	$ (30)	$ 225
Unrealized (losses) gains on cash flow hedges, net of tax	3	19	(11)
Other comprehensive income (loss), net of tax	1,113	(603)	(414)
Ending balance	(398)	(1,511)
MidAmerican Energy Company [Member]
Schedule of accumulated other comprehensive income (loss)
Unrealized gains (losses) on available-for-sale securities, net of tax	0	3	0
Unrealized (losses) gains on cash flow hedges, net of tax	0	0	(7)
Dividend, Noncash, Transfer Of Operations	0	90	0
Other comprehensive income (loss), net of tax	0	3	(7)
Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of accumulated other comprehensive income (loss)
Beginning balance	585	615	390
Beginning balance	26	7	18
Beginning balance	(1,511)	(908)	(494)
Unrealized gains (losses) on available-for-sale securities, net of tax	500	(30)	225
Unrealized (losses) gains on cash flow hedges, net of tax	3	19	(11)
Other comprehensive income (loss), net of tax	1,113	(603)	(414)
Ending balance	1,085	585	615
Ending balance	29	26	7
Ending balance	(398)	(1,511)	(908)
Accumulated Other Comprehensive Income (Loss) [Member] | MidAmerican Energy Company [Member]
Schedule of accumulated other comprehensive income (loss)
Beginning balance	0	(3)
Beginning balance	0	(27)
Beginning balance	$ 0	(30)
Unrealized gains (losses) on available-for-sale securities, net of tax		3
Unrealized (losses) gains on cash flow hedges, net of tax		0
Dividend, Noncash, Transfer Of Operations		27
Other comprehensive income (loss), net of tax		3	(7)
Ending balance		0	(3)
Ending balance		0	(27)
Ending balance		$ 0	$ (30)

Variable-Interest Entities - Pa

Variable-Interest Entities - PacifiCorp (Details) - PacifiCorp [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity, Not Primary Beneficiary [Member]
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	66.67%
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	$ 137	$ 165
Hermiston [Member]
Schedule of Equity Method Investments [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Jim Bridger Unit Nos 1 thru 4 [Member]
Schedule of Equity Method Investments [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	67.00%
Jim Bridger Unit Nos 1 thru 4 [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Schedule of Equity Method Investments [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	66.67%
Jointly Owned Utility Plant, Joint Owner Share	33.33%
Share of coal production purchased by Company	66.67%
Share of coal production purchased by joint venture partner	33.33%

Noncontrolling Interests (Detai

Noncontrolling Interests (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Preferred Securities of Subsidiaries [Line Items]
Preferred stock of subsidiaries, value, outstanding noncontrolling interest, amount represented by preferred stock	$ 58	$ 58
PacifiCorp [Member]
Preferred Securities of Subsidiaries [Line Items]
Preferred stock of subsidiaries, value, outstanding noncontrolling interest, amount represented by preferred stock	2	2
Northern Electric Plc [Member]
Preferred Securities of Subsidiaries [Line Items]
Preferred stock of subsidiaries, value, outstanding noncontrolling interest, amount represented by preferred stock	$ 56	$ 56
Noncontrolling interest, dividend requirements of preferred stock	0.08061	0.08061

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Sales revenue from energy operations		$ 15,171	$ 14,621	$ 15,354
Real estate		3,443	2,801	2,526
Revenues		18,614	17,422	17,880
Depreciation and amortization - energy operations		2,580	2,560	2,399
Depreciation and amortization		2,646	2,591	2,428
Operating income (loss)		4,514	4,251	4,328
Interest expense		1,841	1,854	1,904
Capitalized interest		(45)	(139)	(74)
Allowance for equity funds		76	158	91
Investment Income, Interest and Dividend		111	120	107
Other, net		(398)	36	39
Income before income tax expense and equity income		2,507	2,850	2,735
Income tax (benefit) expense		(554)	403	450
Payments to Acquire Property, Plant, and Equipment		4,571	5,090	5,875
Property, plant and equipment, net		65,871	62,509	60,769
Assets		90,208	85,440	83,618
PacifiCorp [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations		5,237	5,201	5,232
Depreciation and amortization - energy operations		796	783	780
Operating income (loss)		1,462	1,427	1,344
Interest expense		381	381	383
Income tax (benefit) expense		362	341	328
Payments to Acquire Property, Plant, and Equipment		769	903	916
Property, plant and equipment, net		19,203	19,162	19,039
Assets		23,086	23,563	23,550
MidAmerican Funding [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations		2,846	2,631	2,515
Depreciation and amortization - energy operations		500	479	407
Operating income (loss)		562	566	451
Interest expense		237	218	206
Income tax (benefit) expense		(202)	(139)	(150)
Payments to Acquire Property, Plant, and Equipment		1,776	1,637	1,448
Property, plant and equipment, net		14,221	12,835	11,737
Assets		18,444	17,571	16,315
NV Energy [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations		3,015	2,895	3,351
Depreciation and amortization - energy operations		422	421	410
Operating income (loss)		765	770	812
Interest expense		233	250	262
Income tax (benefit) expense		221	200	207
Payments to Acquire Property, Plant, and Equipment		456	529	571
Property, plant and equipment, net		9,770	9,825	9,767
Assets		13,903	14,320	14,656
Northern Powergrid Holdings [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations		949	995	1,140
Depreciation and amortization - energy operations		214	200	202
Operating income (loss)		436	494	593
Interest expense		133	136	145
Income tax (benefit) expense		57	22	35
Payments to Acquire Property, Plant, and Equipment		579	579	674
Property, plant and equipment, net		6,075	5,148	5,790
Assets		7,565	6,433	7,317
BHE Pipeline Group [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations		993	978	1,016
Depreciation and amortization - energy operations		159	206	204
Operating income (loss)		475	455	464
Interest expense		43	50	66
Income tax (benefit) expense		170	163	158
Payments to Acquire Property, Plant, and Equipment		286	226	240
Property, plant and equipment, net		4,587	4,423	4,345
Assets		5,134	5,144	4,953
BHE Transmission [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations		699	502	592
Depreciation and amortization - energy operations		239	241	185
Operating income (loss)		322	92	260
Interest expense		169	153	146
Income tax (benefit) expense		(124)	26	63
Payments to Acquire Property, Plant, and Equipment		334	466	966
Property, plant and equipment, net		6,330	5,810	5,301
Assets		9,009	8,378	7,553
BHE Renewables [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations		838	743	728
Depreciation and amortization - energy operations		251	230	216
Operating income (loss)		316	256	255
Interest expense		204	198	193
Income tax (benefit) expense		(795)	(32)	41
Payments to Acquire Property, Plant, and Equipment		323	719	1,034
Property, plant and equipment, net		5,637	5,302	4,805
Assets		7,687	7,010	5,892
HomeServices [Member]
Segment Reporting Information [Line Items]
Real estate		3,443	2,801	2,526
Depreciation and amortization		66	31	29
Operating income (loss)		214	212	184
Interest expense		7	2	3
Income tax (benefit) expense		49	81	72
Payments to Acquire Property, Plant, and Equipment		37	20	16
Property, plant and equipment, net		117	78	70
Assets		2,722	1,776	1,705
Other [Member]
Segment Reporting Information [Line Items]
Sales revenue from energy operations	[1]	594	676	780
Depreciation and amortization - energy operations	[1]	(1)	0	(5)
Operating income (loss)	[1]	(38)	(21)	(35)
Interest expense	[1]	434	466	500
Income tax (benefit) expense	[1]	(292)	(259)	(304)
Payments to Acquire Property, Plant, and Equipment		11	11	10
Property, plant and equipment, net		(69)	(74)	(85)
Assets		2,658	1,245	1,677
UNITED STATES
Segment Reporting Information [Line Items]
Revenues		16,916	15,895	16,121
Income before income tax expense and equity income		1,927	2,264	2,034
Property, plant and equipment, net		53,579	51,671	49,680
UNITED KINGDOM
Segment Reporting Information [Line Items]
Revenues		948	995	1,140
Income before income tax expense and equity income		313	382	472
Property, plant and equipment, net		5,953	5,020	5,757
CANADA
Segment Reporting Information [Line Items]
Revenues		699	506	600
Income before income tax expense and equity income		167	135	165
Property, plant and equipment, net		6,323	5,803	5,298
The Philippines and other [Member]
Segment Reporting Information [Line Items]
Revenues		51	26	19
Income before income tax expense and equity income		100	69	64
Property, plant and equipment, net		$ 16	$ 15	$ 34
[1]	(1)The differences between the reportable segment amounts and the consolidated amounts, described as BHE and Other, relate to other corporate entities, including MidAmerican Energy Services, LLC, corporate functions and intersegment eliminations.

Segment Information - Goodwill

Segment Information - Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning balance	$ 9,010	$ 9,076
Acquisitions	508	50
Foreign currency translation	162	(86)
Other	(2)	(30)
Ending balance	9,678	9,010
PacifiCorp [Member]
Goodwill [Roll Forward]
Beginning balance	1,129	1,129
Acquisitions	0	0
Foreign currency translation	0	0
Other	0	0
Ending balance	1,129	1,129
MidAmerican Funding [Member]
Goodwill [Roll Forward]
Beginning balance	2,102	2,102
Acquisitions	0	0
Foreign currency translation	0	0
Other	0	0
Ending balance	2,102	2,102
NV Energy [Member]
Goodwill [Roll Forward]
Beginning balance	2,369	2,369
Acquisitions	0	0
Foreign currency translation	0	0
Other	0	0
Ending balance	2,369	2,369
Northern Powergrid Holdings [Member]
Goodwill [Roll Forward]
Beginning balance	930	1,056
Acquisitions	0	0
Foreign currency translation	61	(126)
Other	0	0
Ending balance	991	930
BHE Pipeline Group [Member]
Goodwill [Roll Forward]
Beginning balance	75	101
Acquisitions	0	0
Foreign currency translation	0	0
Other	(2)	(26)
Ending balance	73	75
BHE Transmission [Member]
Goodwill [Roll Forward]
Beginning balance	1,470	1,428
Acquisitions	0	4
Foreign currency translation	101	42
Other	0	(4)
Ending balance	1,571	1,470
BHE Renewables [Member]
Goodwill [Roll Forward]
Beginning balance	95	95
Acquisitions	0	0
Foreign currency translation	0	0
Other	0	0
Ending balance	95	95
HomeServices [Member]
Goodwill [Roll Forward]
Beginning balance	840	794
Acquisitions	508	46
Foreign currency translation	0	0
Other	0	0
Ending balance	1,348	840
Other [Member]
Goodwill [Roll Forward]
Beginning balance	0	2
Acquisitions	0	0
Foreign currency translation	0	(2)
Other	0	0
Ending balance	$ 0	$ 0

Segment Information - MEC (Deta

Segment Information - MEC (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)OperatingSegmentsTheNumberOfReportableSegments	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | OperatingSegments									8
Revenues									$ 18,614	$ 17,422	$ 17,880
Operating income (loss)									4,514	4,251	4,328
Interest expense									1,841	1,854	1,904
Income tax (benefit) expense									(554)	403	450
Net income attributable to BHE shareholders									2,870	2,542	2,370
Payments to Acquire Property, Plant, and Equipment									4,571	5,090	5,875
Assets	$ 90,208				$ 85,440				$ 90,208	85,440	83,618
MidAmerican Energy Company [Member]
Segment Reporting Information [Line Items]
Number of Reportable Segments | TheNumberOfReportableSegments									2
Electric Domestic Regulated Revenue									$ 2,108	1,985	1,837
Revenues	671	$ 813	$ 658	$ 695	621	$ 795	$ 584	$ 625	2,837	2,625	2,502
Utilities Operating Expense, Depreciation and Amortization									500	479	407
Operating income (loss)	31	288	135	107	42	284	139	100	561	565	449
Interest expense									214	196	183
Income tax (benefit) expense									(183)	(132)	(147)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									605	542	446
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									0	0	16
Net income attributable to BHE shareholders	(19)	$ 385	$ 134	$ 105	15	$ 320	$ 131	$ 76	605	542	462
Payments to Acquire Property, Plant, and Equipment									1,773	1,636	1,446
Assets	16,318				15,459				16,318	15,459	14,385
MidAmerican Energy Company [Member] | Regulated Electric [Member]
Segment Reporting Information [Line Items]
Electric Domestic Regulated Revenue									2,108	1,985	1,837
Utilities Operating Expense, Depreciation and Amortization									458	436	366
Operating income (loss)									485	497	385
Interest expense									196	178	166
Income tax (benefit) expense									(212)	(156)	(163)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									570	512	413
Payments to Acquire Property, Plant, and Equipment									1,686	1,564	1,365
Assets	14,914				14,113				14,914	14,113	12,970
MidAmerican Energy Company [Member] | Regulated Gas [Member]
Segment Reporting Information [Line Items]
Gas Domestic Regulated Revenue									719	637	661
Utilities Operating Expense, Depreciation and Amortization									42	43	41
Operating income (loss)									77	68	64
Interest expense									18	18	17
Income tax (benefit) expense									29	22	16
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									35	32	33
Payments to Acquire Property, Plant, and Equipment									87	72	81
Assets	1,403				1,345				1,403	1,345	1,251
MidAmerican Energy Company [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Other Revenue, Net									10	3	4
Operating income (loss)									(1)	0	0
Income tax (benefit) expense									0	2	0
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									0	(2)	0
Assets	$ 1				$ 1				$ 1	$ 1	$ 164

Segment Information - MidAmeric

Segment Information - MidAmerican Funding (Details) $ in Millions	3 Months Ended							9 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2017USD ($)OperatingSegmentsTheNumberOfReportableSegments	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | OperatingSegments									8
Revenues									$ 18,614	$ 17,422	$ 17,880
Operating income (loss)									4,514	4,251	4,328
Interest expense									1,841	1,854	1,904
Income tax (benefit) expense									(554)	403	450
Net income (loss) attributable to parent									2,870	2,542	2,370
Payments to Acquire Property, Plant, and Equipment									4,571	5,090	5,875
Assets	$ 90,208				$ 85,440				90,208	85,440	83,618
Goodwill	9,678				9,010				$ 9,678	9,010	9,076
MidAmerican Funding, LLC and Subsidiaries [Domain]
Segment Reporting Information [Line Items]
Number of Reportable Segments | TheNumberOfReportableSegments									2
Electric Domestic Regulated Revenue									$ 2,108	1,985	1,837
Revenues	676	$ 815	$ 659	$ 696	623	$ 585	$ 626	$ 797	2,846	2,631	2,515
Utilities Operating Expense, Depreciation and Amortization									500	479	407
Operating income (loss)	31	288	136	107	42	140	100	284	562	566	451
Interest expense									237	219	206
Income tax (benefit) expense									(202)	(139)	(150)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									574	532	442
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									0	0	16
Net income (loss) attributable to parent	(42)	$ 383	$ 131	$ 102	14	$ 127	$ 73	$ 318	574	532	458
Payments to Acquire Property, Plant, and Equipment									1,773	1,636	1,446
Assets	17,621				16,747				17,621	16,747	15,674
Goodwill	1,270				1,270				1,270	1,270
MidAmerican Funding, LLC and Subsidiaries [Domain] | Regulated Electric [Member]
Segment Reporting Information [Line Items]
Electric Domestic Regulated Revenue									2,108	1,985	1,837
Utilities Operating Expense, Depreciation and Amortization									458	436	366
Operating income (loss)									485	497	385
Interest expense									196	178	166
Income tax (benefit) expense									(212)	(156)	(163)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									570	512	413
Payments to Acquire Property, Plant, and Equipment									1,686	1,564	1,365
Assets	16,105				15,304				16,105	15,304	14,161
Goodwill	1,191				1,191				1,191	1,191
MidAmerican Funding, LLC and Subsidiaries [Domain] | Regulated Gas [Member]
Segment Reporting Information [Line Items]
Gas Domestic Regulated Revenue									719	637	661
Utilities Operating Expense, Depreciation and Amortization									42	43	41
Operating income (loss)									77	68	64
Interest expense									18	18	17
Income tax (benefit) expense									29	22	16
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									35	32	33
Payments to Acquire Property, Plant, and Equipment									87	72	81
Assets	1,482				1,424				1,482	1,424	1,330
Goodwill	79				79				79	79
MidAmerican Funding, LLC and Subsidiaries [Domain] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Other Revenue, Net									19	9	17
Operating income (loss)									0	1	2
Interest expense									23	23	23
Income tax (benefit) expense									(19)	(5)	(3)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									(31)	(12)	(4)
Assets	$ 34				$ 19				$ 34	$ 19	$ 183

Segment Information - SPPC (Det

Segment Information - SPPC (Details) $ in Millions		12 Months Ended
		Dec. 31, 2017USD ($)OperatingSegmentsTheNumberOfReportableSegments	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | OperatingSegments		8
Revenues		$ 18,614	$ 17,422	$ 17,880
Cost of sales		4,518	4,315	5,079
Operating income (loss)		4,514	4,251	4,328
Income tax (benefit) expense		(554)	403	450
Payments to Acquire Property, Plant, and Equipment		4,571	5,090	5,875
Assets		$ 90,208	85,440	83,618
Sierra Pacific Power Company [Member]
Segment Reporting Information [Line Items]
Number of Reportable Segments | TheNumberOfReportableSegments		2
Electric Domestic Regulated Revenue		$ 713	702	810
Gas Domestic Regulated Revenue		99	110	137
Revenues		812	812	947
Cost of sales		268	265	374
Cost of Purchased Oil and Gas		42	55	84
Cost of Sales		310	320	458
Gross Margin		502	492	489
Operations and maintenance		166	170	167
Utilities Operating Expense, Depreciation and Amortization		114	118	113
Operating income (loss)		198	180	184
Interest expense, net of borrowed funds		43	54	61
Income tax (benefit) expense		55	49	47
Payments to Acquire Property, Plant, and Equipment		186	194	252
Assets		3,413	3,493	3,487
Sierra Pacific Power Company [Member] | Electric Operations [Member]
Segment Reporting Information [Line Items]
Electric Domestic Regulated Revenue		713	702	810
Cost of sales		268	265	374
Electric Domestic Regulated Gross Margin		445	437	436
Electricity, Utilities Operating Expense, Maintenance and Operations		148	153	149
Utilities Operating Expense, Depreciation and Amortization		100	101	96
Operating income (loss)		176	161	168
Electric, Interest Expense, net of allowance for borrowed funds		39	49	56
Income tax (benefit) expense		48	44	43
Payments to Acquire Property, Plant, and Equipment		169	176	229
Assets		3,103	3,119	3,060
Sierra Pacific Power Company [Member] | Natural Gas Operations [Member]
Segment Reporting Information [Line Items]
Gas Domestic Regulated Revenue		99	110	137
Cost of Purchased Oil and Gas		42	55	84
Gas Domestic Regulated Gross Margin		57	55	53
Gas, Utilities Operating Expense, Maintenance and Operations		18	17	18
Utilities Operating Expense, Depreciation and Amortization		14	17	17
Operating income (loss)		22	19	16
Gas, Interest Expense, net of allowance for borrowed funds		4	5	5
Income tax (benefit) expense		7	5	4
Payments to Acquire Property, Plant, and Equipment		17	18	23
Assets		300	314	316
Sierra Pacific Power Company [Member] | Regulated common assets [Member]
Segment Reporting Information [Line Items]
Assets	[1]	$ 10	$ 60	$ 111
[1]	Consists principally of cash and cash equivalents not included in either the regulated electric or regulated natural gas segments.

Subsequent Events (MEC) Subsequ

Subsequent Events (MEC) Subsequent Events - MEC (Details) - USD ($) $ in Millions	Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Par value		$ 35,376
MidAmerican Energy Company [Member]
Subsequent Event [Line Items]
Par value		5,080
MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.95%, Due 2047 [Member]
Subsequent Event [Line Items]
Par value		475
MidAmerican Energy Company [Member] | MEC Notes, 5.95% Series, due 2017 [Member]
Subsequent Event [Line Items]
Par value		$ 0
Debt Instrument, Interest Rate, Stated Percentage		5.95%	5.95%
MidAmerican Energy Company [Member] | Subsequent Event [Member] | MidAmerican Energy Company [Member] | MEC First Mortgage Bonds, 3.65%, Due August 2048 [Member]
Subsequent Event [Line Items]
Par value	$ 700
Debt Instrument, Interest Rate, Stated Percentage	3.65%

Unaudited Quarterly Operatin283

Unaudited Quarterly Operating Results - MEC (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Operating Results [Line Items]
Revenues									$ 18,614	$ 17,422	$ 17,880
Operating income (loss)									4,514	4,251	4,328
Net income attributable to BHE shareholders									2,870	2,542	2,370
MidAmerican Energy Company [Member]
Quarterly Operating Results [Line Items]
Revenues	$ 671	$ 813	$ 658	$ 695	$ 621	$ 795	$ 584	$ 625	2,837	2,625	2,502
Operating income (loss)	31	288	135	107	42	284	139	100	561	565	449
Net income attributable to BHE shareholders	$ (19)	$ 385	$ 134	$ 105	$ 15	$ 320	$ 131	$ 76	$ 605	$ 542	$ 462

Unaudited Quarterly Operatin284

Unaudited Quarterly Operating Results - MidAmerican Funding (Details) - USD ($) $ in Millions	3 Months Ended							9 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Operating Results [Line Items]
Revenues									$ 18,614	$ 17,422	$ 17,880
Operating income (loss)									4,514	4,251	4,328
Net income attributable to BHE shareholders									2,870	2,542	2,370
MidAmerican Funding, LLC and Subsidiaries [Domain]
Quarterly Operating Results [Line Items]
Revenues	$ 676	$ 815	$ 659	$ 696	$ 623	$ 585	$ 626	$ 797	2,846	2,631	2,515
Operating income (loss)	31	288	136	107	42	140	100	284	562	566	451
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent									574	532	442
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									0	0	16
Net income attributable to BHE shareholders	$ (42)	$ 383	$ 131	$ 102	$ 14	$ 127	$ 73	$ 318	$ 574	$ 532	$ 458

Unaudited Quarterly Operatin285

Unaudited Quarterly Operating Results - NPC (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Operating Results [Line Items]
Operating income (loss)									$ 4,514	$ 4,251	$ 4,328
Net income attributable to BHE shareholders									2,870	2,542	2,370
Nevada Power Company [Member]
Quarterly Operating Results [Line Items]
Electric Domestic Regulated Revenue	$ 421	$ 819	$ 574	$ 392	$ 393	$ 766	$ 525	$ 399
Operating income (loss)	37	317	157	52	69	324	141	46	563	580	613
Net income attributable to BHE shareholders	$ (8)	$ 176	$ 77	$ 10	$ 22	$ 188	$ 66	$ 3	$ 255	$ 279	$ 288

Unaudited Quarterly Operatin286

Unaudited Quarterly Operating Results - SPPC (Details) - Sierra Pacific Power Company [Member] - USD ($) $ in Millions	3 Months Ended							9 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2016
Quarterly Operating Results [Line Items]
Electric Domestic Operating Revenue, Quarterly	$ 179	$ 215	$ 160	$ 159	$ 163	$ 162	$ 170	$ 207
Gas Domestic Operating Revenue, Quarterly	33	15	17	34	29	19	47	15
Operating Income (loss), Quarterly	41	75	36	46	42	28	41	69
Net Income (Loss) Attributable to Parent, Quarterly	$ 24	$ 44	$ 17	$ 24	$ 19	$ 10	$ 17	$ 38

Schedule I Condensed Balance287

Schedule I Condensed Balance Sheets (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents		$ 935	$ 721	$ 1,108	$ 617
Accounts receivable		2,014	1,751
Income tax receivable		334	0
Other current assets		815	706
Total current assets		5,778	4,673
Goodwill		9,678	9,010	9,076
Other assets		1,248	996
Total assets		90,208	85,440	83,618
Current liabilities:
Short-term debt	[1]	4,488	1,869
Total current liabilities		11,603	6,313
BHE senior debt		5,452	7,418
BHE junior subordinated debentures		100	944
Long-term Debt		35,193	36,116
Other long-term liabilities		2,984	2,742
Total liabilities		61,900	60,977
Shareholders' equity:
Common stock		0	0
Additional paid-in capital		6,368	6,390
Retained earnings		22,206	19,448
Accumulated other comprehensive loss, net		(398)	(1,511)
Total shareholders' equity		28,176	24,327
Noncontrolling interest		132	136
Total equity		28,308	24,463	22,535	20,573
Total liabilities and equity		90,208	85,440
Parent Company [Member]
Current assets:
Cash and cash equivalents		346	33	23	3
Accounts receivable		0	21
Accounts Receivable, Related Parties		60	0
Due from Affiliates		391	105
Other current assets		21	2
Total current assets		818	161
Investments in subsidiaries		34,019	33,400
Other Investments		2,117	1,338
Goodwill		1,221	1,221
Other assets		1,155	1,171
Total assets		39,330	37,291
Current liabilities:
Accounts payable and other current liabilities		268	357
Notes Payable, Related Parties, Current		182	194
Short-term debt		3,331	834
Current portion of senior debt		1,000	400
Total current liabilities		4,781	1,785
BHE senior debt		5,452	7,418
BHE junior subordinated debentures		100	944
Notes payable - affiliate		1	1,859
Other long-term liabilities		800	942
Total liabilities		11,134	12,948
Shareholders' equity:
Common stock		0	0
Additional paid-in capital		6,368	6,390
Retained earnings		22,206	19,448
Accumulated other comprehensive loss, net		(398)	(1,511)
Total shareholders' equity		28,176	24,327
Noncontrolling interest		20	16
Total equity		28,196	24,343
Total liabilities and equity		39,330	37,291
MidAmerican Funding LLC [Member]
Current assets:
Cash and cash equivalents		0	0	$ 0	$ 0
Due from Affiliates		2	2
Income tax receivable		13	0
Total current assets		15	2
Investments in subsidiaries		7,322	6,718
Total assets		7,337	6,720
Current liabilities:
Other accrued current liabilities		6	7
Long-term Debt		240	326
Notes payable - affiliate		431	301
Total liabilities		677	634
Shareholders' equity:
Paid-in capital		1,679	1,679
Retained earnings		4,981	4,407
Total shareholders' equity		6,660	6,086
Total liabilities and equity		$ 7,337	$ 6,720
[1]	(1)The table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.

Schedule I Condensed Statements

Schedule I Condensed Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating costs and expenses:
Depreciation and amortization	$ 2,646	$ 2,591	$ 2,428
Total operating costs and expenses	14,100	13,171	13,552
Operating loss	4,514	4,251	4,328
Other income (expense):
Interest expense	(1,841)	(1,854)	(1,904)
Other, net	(398)	36	39
Total other income (expense)	(2,007)	(1,401)	(1,593)
Loss before income tax benefit and equity income	2,507	2,850	2,735
Income tax (benefit) expense	(554)	403	450
Equity income (loss)	(151)	123	115
Net income	2,910	2,570	2,400
Net income attributable to noncontrolling interests	40	28	30
Net income (loss) attributable to parent	2,870	2,542	2,370
Parent Company [Member]
Operating costs and expenses:
General and administration	55	51	58
Depreciation and amortization	4	4	3
Total operating costs and expenses	59	55	61
Operating loss	(59)	(55)	(61)
Other income (expense):
Interest expense	(475)	(527)	(556)
Other, net	(369)	37	14
Total other income (expense)	(844)	(490)	(542)
Loss before income tax benefit and equity income	(903)	(545)	(603)
Income tax (benefit) expense	(335)	(285)	(330)
Equity income (loss)	3,441	2,805	2,646
Net income	2,873	2,545	2,373
Net income attributable to noncontrolling interests	3	3	3
Net income (loss) attributable to parent	2,870	2,542	2,370
MidAmerican Funding LLC [Member]
Other income (expense):
Other, net	(30)	0	0
Interest Expense, Long-term Debt	(22)	(22)	(22)
Loss before income tax benefit and equity income	(52)	(22)	(22)
Income tax (benefit) expense	(22)	(9)	(8)
Equity income (loss)	604	545	472
Net income (loss) attributable to parent	$ 574	$ 532	$ 458

Schedule I Condensed Stateme289

Schedule I Condensed Statements of Comprehensive Income Schedule I Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Net income attributable to BHE shareholders	$ 2,870	$ 2,542	$ 2,370
Net income	2,910	2,570	2,400
Other comprehensive income (loss), net of tax	1,113	(603)	(414)
Comprehensive income	4,023	1,967	1,986
Comprehensive income attributable to noncontrolling interests	40	28	30
Comprehensive income attributable to BHE shareholders	3,983	1,939	1,956
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net income attributable to BHE shareholders	2,870	2,542	2,370
Net income	2,873	2,545	2,373
Other comprehensive income (loss), net of tax	1,113	(603)	(414)
Comprehensive income	3,986	1,942	1,959
Comprehensive income attributable to noncontrolling interests	3	3	3
Comprehensive income attributable to BHE shareholders	3,983	1,939	1,956
MidAmerican Funding LLC [Member]
Condensed Financial Statements, Captions [Line Items]
Net income attributable to BHE shareholders	574	532	458
Other comprehensive income (loss), net of tax	0	3	(7)
Comprehensive income attributable to BHE shareholders	$ 574	$ 535	$ 451

Schedule I Condensed Stateme290

Schedule I Condensed Statements of Cash Flows Schedule I Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	$ 6,066	$ 6,056	$ 6,980
Cash flows from investing activities:
Purchases of available-for-sale securities	(190)	(141)	(144)
Proceeds from sale of investments	202	191	142
Other, net	(12)	(34)	41
Net cash flows from investing activities	(6,133)	(5,746)	(6,230)
Cash flows from financing activities:
Payment for Debt Extinguishment or Debt Prepayment Cost	(435)	0	0
Payments for Repurchase of Common Stock	19	0	36
Net proceeds from (repayments of) short-term debt	2,361	879	(421)
Other, net	(73)	(65)	(73)
Net cash flows from financing activities	274	(690)	(255)
Net change in cash and cash equivalents	214	(387)	491
Cash and cash equivalents at beginning of period	721	1,108	617
Cash and cash equivalents at end of period	935	721	1,108
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	2,450	2,760	2,528
Cash flows from investing activities:
Investments in subsidiaries	(1,566)	(1,080)	(1,506)
Purchases of available-for-sale securities	(71)	(24)	(36)
Proceeds from sale of investments	68	20	47
Notes receivable from affiliate, net	(305)	(307)	19
Other, net	(8)	(5)	(7)
Net cash flows from investing activities	(1,882)	(1,396)	(1,483)
Cash flows from financing activities:
Repayments of BHE senior debt	(1,379)	0	0
Repayments of BHE subordinated debt	(944)	(2,000)	(850)
Payment for Debt Extinguishment or Debt Prepayment Cost	(406)	0	0
Payments for Repurchase of Common Stock	19	0	36
Net proceeds from (repayments of) short-term debt	2,498	581	(142)
Notes payable to affiliate, net	0	69	4
Other, net	(5)	(4)	(1)
Net cash flows from financing activities	(255)	(1,354)	(1,025)
Net change in cash and cash equivalents	313	10	20
Cash and cash equivalents at beginning of period	33	23	3
Cash and cash equivalents at end of period	346	33	23
MidAmerican Funding LLC [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	(15)	(13)	(13)
Cash flows from investing activities:
Net cash flows from investing activities	0	0	0
Cash flows from financing activities:
Repayments of Long-term Debt	(86)	0	0
Payment for Debt Extinguishment or Debt Prepayment Cost	(29)	0	0
Net change in amounts payable to subsidiary	130	13	13
Net cash flows from financing activities	15	13	13
Net change in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	$ 0	$ 0	$ 0

Condensed Financial Statemen291

Condensed Financial Statements - Other Investments (Details) - BYD Company Limited common stock [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Available-for-sale Securities, Equity Securities	$ 1,961	$ 1,185
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) before Taxes	1,729	953
Parent Company [Member]
Investments, Including Equity Method And Restricted Cash And Investments [Line Items]
Available-for-sale Securities, Equity Securities	1,961	1,185
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss) before Taxes	$ 1,729	$ 953

Condensed Financial Statemen292

Condensed Financial Statements - Dividends and Distributions (Details) - Parent Company [Member] - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 23, 2018	Dec. 31, 2017
Distribution [Line Items]
Proceeds from dividends received		$ 3,000
Subsequent Event [Member]
Distribution [Line Items]
Proceeds from dividends received	$ 158

Condensed Financial Statemen293

Condensed Financial Statements - Guarantees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Tax Equity Contributions	$ 403	$ 584	$ 170
Parent Company [Member]
Debt Instrument [Line Items]
Guarantor obligations, related party disclosure	236
Tax Equity Contributions	$ 265

Schedule I Condensed Financial

Schedule I Condensed Financial Statements Condensed Financial Statements - MidAmerican Funding - Payable to Affiliate (Details) - MidAmerican Funding LLC [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Net change in amounts payable to subsidiary	$ 130	$ 13	$ 13
MHC, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Net change in amounts payable to subsidiary	$ 130	$ 13	$ 13

Schedule II Consolidated Val295

Schedule II Consolidated Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		$ 33	$ 31	$ 37
Valuation Allowances and Reserves, Charged to Cost and Expense		42	39	33
Valuation Allowances and Reserves, Adjustments		0	0	0
Valuation Allowances and Reserves, Deductions		(35)	(37)	(39)
Balance at End of Year		40	33	31
Reserves not deducted from assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	[1]	13	13	11
Valuation Allowances and Reserves, Charged to Cost and Expense	[1]	7	5	7
Valuation Allowances and Reserves, Adjustments	[1]	0	0	0
Valuation Allowances and Reserves, Deductions	[1]	(7)	(5)	(5)
Balance at End of Year	[1]	$ 13	$ 13	$ 13
[1]	serves not deducted from assets relate primarily to estimated liabilities for losses retained by BHE for workers compensation, public liability and property damage claims.

Schedule II Consolidated Val296

Schedule II Consolidated Valuation and Qualifying Accounts - MEC (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		$ 33	$ 31	$ 37
Valuation Allowances and Reserves, Charged to Cost and Expense		42	39	33
Valuation Allowances and Reserves, Deductions		(35)	(37)	(39)
Valuation Allowances and Reserves, Balance		33	31	37	$ 40
Reserves not deducted from assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	[1]	13	13	11
Valuation Allowances and Reserves, Charged to Cost and Expense	[1]	7	5	7
Valuation Allowances and Reserves, Deductions	[1]	(7)	(5)	(5)
Valuation Allowances and Reserves, Balance	[1]	13	13	11	13
MidAmerican Energy Company [Member] | Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		7	6	7
Valuation Allowances and Reserves, Charged to Cost and Expense		8	7	7
Valuation Allowances and Reserves, Deductions		(8)	(6)	(8)
Valuation Allowances and Reserves, Balance		7	6	7	7
MidAmerican Energy Company [Member] | Reserves not deducted from assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		13	13	11
Valuation Allowances and Reserves, Charged to Cost and Expense		7	5	7
Valuation Allowances and Reserves, Deductions		(7)	(5)	(5)
Valuation Allowances and Reserves, Balance		$ 13	$ 13	$ 11	$ 13
[1]	serves not deducted from assets relate primarily to estimated liabilities for losses retained by BHE for workers compensation, public liability and property damage claims.

Schedule II Consolidated Val297

Schedule II Consolidated Valuation and Qualifying Accounts Schedule II Consolidated Valuation and Qualifying Accounts - LLC - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance		$ 40	$ 33	$ 31	$ 37
Valuation Allowances and Reserves, Charged to Cost and Expense		42	39	33
Valuation Allowances and Reserves, Deductions		35	37	39
Reserves not deducted from assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	[1]	13	13	13	11
Valuation Allowances and Reserves, Charged to Cost and Expense	[1]	7	5	7
Valuation Allowances and Reserves, Deductions	[1]	7	5	5
MidAmerican Funding, LLC and Subsidiaries [Domain] | Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance		7	7	6	7
Valuation Allowances and Reserves, Charged to Cost and Expense		8	7	7
Valuation Allowances and Reserves, Deductions		8	6	8
MidAmerican Funding, LLC and Subsidiaries [Domain] | Reserves not deducted from assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance		13	13	13	$ 11
Valuation Allowances and Reserves, Charged to Cost and Expense		7	5	7
Valuation Allowances and Reserves, Deductions		$ 7	$ 5	$ 5
[1]	serves not deducted from assets relate primarily to estimated liabilities for losses retained by BHE for workers compensation, public liability and property damage claims.

Discontinued Operations Disc298

Discontinued Operations Discontinued Operations (Details) - Unregulated Retail Services [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016
MidAmerican Funding, LLC and Subsidiaries [Domain]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operations, net assets and AOCI		$ 117
MidAmerican Energy Company [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operations, revenue	$ 905
Discontinued operations, costs of sales	854
Discontinued operations, cash flows from operations	30
Discontinued operations, net assets and AOCI	$ 90