Duke Energy Carolinas 10-K 2 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 24, 2015	Jun. 30, 2014
Document Information [Line Items]
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Entity Registrant Name	Duke Energy Corporation
Entity Central Index Key	1326160
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		707,544,168
Entity Public Float			$52,431,523,340
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Duke Energy Carolinas [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Carolinas, LLC
Entity Central Index Key	30371
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Progress Energy [Member]
Document Information [Line Items]
Entity Registrant Name	Progress Energy, Inc.
Entity Central Index Key	1094093
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Duke Energy Progress [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Progress, Inc.
Entity Central Index Key	17797
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Duke Energy Florida [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Florida, Inc.
Entity Central Index Key	37637
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Duke Energy Ohio [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Ohio, Inc.
Entity Central Index Key	20290
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Duke Energy Indiana [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Indiana, Inc.
Entity Central Index Key	81020
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Severance Expense Net Of Payments					$92
Operating Revenues [Abstract]
Regulated electric	21,550		20,329		15,515
Non-regulated electric, natural gas, and other	1,802		1,916		1,928
Regulated natural gas	573		511		469
Total operating revenues	23,925		22,756		17,912
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	7,686		7,108		5,582
Fuel used in electric generation and purchased power - non-regulated	533		540		651
Cost of natural gas and other	248		224		215
Operation, maintenance and other	5,856		5,673		4,787
Depreciation and amortization	3,066		2,668		2,145
Property and other taxes	1,213		1,274		965
Impairment charges	81		399		666
Total operating expenses	18,683		17,886		15,011
Gains (Losses) on Sales of Other Assets and Other, net	16		-16		10
Operating Income (Loss)	5,258		4,854		2,911
Other Income and Expenses [Abstract]
Equity in earnings of unconsolidated affiliates	130		122		148
Gains on sales of unconsolidated affiliates	17		100		22
Other income and expenses, net	351		262		397
Total other income and expenses	498		484		567
Interest Expense	1,622		1,543		1,244
Income (Loss) From Continuing Operations Before Income Taxes	4,134		3,795		2,234
Income Tax Expense (Benefit) from Continuing Operations	1,669		1,205		623
Net income	1,889		2,676		1,782
Income (Loss) from Continuing Operations	2,465		2,590		1,611
Income (Loss) From Discontinued Operations, net of tax	-576		86		171
Less: Net Income (Loss) Attributable to Noncontrolling Interests	6		11		14
Net Income (Loss) Attributable to Parent	1,883		2,665		1,768
Net Income (Loss) Available to Parent			2,676		1,780	[1]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments	4	[2]	38	[2]	19	[2]
Net unrealized gain (loss) on cash flow hedges	-26	[3]	59	[3]	-28	[3]
Reclassification into earnings from cash flow hedges	7		1		-1
Unrealized gain (loss) on investments in available for sale securities	3		-4		14
Other comprehensive income (loss), net of tax	-136		-99		-76
Comprehensive Income (Loss)	1,753		2,577		1,706
Less: Comprehensive Income Attributable to Noncontrolling Interests	14		5		10
Comprehensive income (loss)	1,739		2,572		1,696
Income From Continuing Operations Attributable To Parent Common Shareholders [Abstract]
Basic	$3.46		$3.64		$2.77
Diluted	$3.46		$3.63		$2.77
Income (loss) from discontinued operations attributable To Duke Energy Corporation common shareholders [Abstract]
Basic	($0.80)		$0.13		$0.30
Diluted	($0.80)		$0.13		$0.30
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$2.66		$3.77		$3.07
Diluted	$2.66		$3.76		$3.07
Weighted-average shares outstanding [Abstract]
Basic	707		706		574
Diluted	707		706		575
Duke Energy Carolinas [Member]
Operating Revenues [Abstract]
Total operating revenues	7,351		6,954		6,665
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	2,133		1,982		1,864
Operation, maintenance and other	1,995		1,868		1,979
Depreciation and amortization	1,009		921		921
Property and other taxes	316		374		365
Impairment charges	3				31
Total operating expenses	5,456		5,145		5,160
Gains (Losses) on Sales of Other Assets and Other, net					12
Operating Income (Loss)	1,895		1,809		1,517
Other Income and Expenses [Abstract]
Other income and expenses, net	172		120		185
Interest Expense	407		359		384
Income (Loss) From Continuing Operations Before Income Taxes	1,660		1,570		1,318
Income Tax Expense (Benefit) from Continuing Operations	588		594		453
Net income	1,072		976
Net Income (Loss) Attributable to Parent	1,072		976		865
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges	2		1		2
Unrealized gain (loss) on investments in available for sale securities					1
Other comprehensive income (loss), net of tax	2		1		3
Comprehensive income (loss)	1,074		977		868
Progress Energy [Member]
Severance Expense Net Of Payments					38
Operating Revenues [Abstract]
Total operating revenues	10,166		9,533		9,405
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	4,195		3,851		4,304
Operation, maintenance and other	2,335		2,247		2,445
Depreciation and amortization	1,128		883		747
Property and other taxes	517		557		570
Impairment charges	-16		380		200
Total operating expenses	8,159		7,918		8,266
Gains (Losses) on Sales of Other Assets and Other, net	11		3		-2
Operating Income (Loss)	2,018		1,618		1,137
Other Income and Expenses [Abstract]
Other income and expenses, net	77		94		130
Interest Expense	675		680		740
Income (Loss) From Continuing Operations Before Income Taxes	1,420		1,032		527
Income Tax Expense (Benefit) from Continuing Operations	540		373		172
Net income	874		675		407
Income (Loss) from Continuing Operations	880		659		355
Income (Loss) From Discontinued Operations, net of tax	-6		16		52
Less: Net Income (Loss) Attributable to Noncontrolling Interests	5		3		7
Net Income (Loss) Attributable to Parent	869		672		400
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments	9		9		-2
Net unrealized gain (loss) on cash flow hedges					-5
Reclassification into earnings from cash flow hedges	8		-1		8
Reclassification of cash flow hedges to regulatory assets					97	[4]
Unrealized gain (loss) on investments in available for sale securities	1
Other comprehensive income (loss), net of tax	18		8		98
Comprehensive Income (Loss)	892		683		505
Less: Comprehensive Income Attributable to Noncontrolling Interests	5		3		7
Comprehensive income (loss)	887		680		498
Duke Energy Progress [Member]
Severance Expense Net Of Payments					18
Operating Revenues [Abstract]
Total operating revenues	5,176		4,992		4,706
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	2,036		1,925		1,895
Operation, maintenance and other	1,470		1,357		1,494
Depreciation and amortization	582		534		535
Property and other taxes	174		223		219
Impairment charges	-18		22		54
Total operating expenses	4,244		4,061		4,197
Gains (Losses) on Sales of Other Assets and Other, net	3		1		1
Operating Income (Loss)	935		932		510
Other Income and Expenses [Abstract]
Other income and expenses, net	51		57		79
Interest Expense	234		201		207
Income (Loss) From Continuing Operations Before Income Taxes	752		788		382
Income Tax Expense (Benefit) from Continuing Operations	285		288		110
Net income	467		500		272
Less: Preferred Stock Dividend Requirement					3
Net Income (Loss) Available to Parent	467		500		269
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized gain (loss) on cash flow hedges					-4
Reclassification into earnings from cash flow hedges					4
Reclassification of cash flow hedges to regulatory assets					71	[5]
Other comprehensive income (loss), net of tax	0		0		71
Comprehensive income (loss)	467		500		343
Duke Energy Florida [Member]
Severance Expense Net Of Payments					6
Operating Revenues [Abstract]
Total operating revenues	4,975		4,527		4,689
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	2,158		1,927		2,409
Operation, maintenance and other	850		898		969
Depreciation and amortization	545		330		192
Property and other taxes	343		327		346
Impairment charges	2		358		146
Total operating expenses	3,898		3,840		4,062
Gains (Losses) on Sales of Other Assets and Other, net	1		1		2
Operating Income (Loss)	1,078		688		629
Other Income and Expenses [Abstract]
Other income and expenses, net	20		30		39
Interest Expense	201		180		255
Income (Loss) From Continuing Operations Before Income Taxes	897		538		413
Income Tax Expense (Benefit) from Continuing Operations	349		213		147
Net income	548		325		266
Less: Preferred Stock Dividend Requirement	0		0		2
Net Income (Loss) Available to Parent	548		325		264
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized gain (loss) on cash flow hedges	0		-1		0
Reclassification into earnings from cash flow hedges	1		0		1
Reclassification of cash flow hedges to regulatory assets	0	[6]	0	[6]	26	[6]
Other comprehensive income (loss), net of tax	1		-1		27
Comprehensive income (loss)	549		324		293
Duke Energy Ohio [Member]
Operating Revenues [Abstract]
Regulated electric	1,316		1,258		1,281
Non-regulated electric, natural gas, and other	19		34		68
Regulated natural gas	578		513		471
Total operating revenues	1,913		1,805		1,820
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	459		428		475
Fuel used in electric generation and purchased power - non-regulated	25		41		57
Cost of natural gas and other	185		152		142
Operation, maintenance and other	516		546		586
Depreciation and amortization	214		213		195
Property and other taxes	234		242		205
Impairment charges	94		5		2
Total operating expenses	1,727		1,627		1,662
Gains (Losses) on Sales of Other Assets and Other, net	1		4		1
Operating Income (Loss)	187		182		159
Other Income and Expenses [Abstract]
Other income and expenses, net	10		2		8
Interest Expense	86		74		89
Income (Loss) From Continuing Operations Before Income Taxes	111		110		78
Income Tax Expense (Benefit) from Continuing Operations	43		43		33
Net income	-495		102		175
Income (Loss) from Continuing Operations	68		67		45
Income (Loss) From Discontinued Operations, net of tax	-563		35		130
Net Income (Loss) Attributable to Parent	-495		102		175
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments			1		27
Other comprehensive income (loss), net of tax			1		27
Comprehensive income (loss)	-495		103		202
Duke Energy Indiana [Member]
Operating Revenues [Abstract]
Total operating revenues	3,175		2,926		2,717
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated	1,259		1,131		1,088
Operation, maintenance and other	670		649		655
Depreciation and amortization	413		342		389
Property and other taxes	128		71		81
Impairment charges	0		0		579
Total operating expenses	2,470		2,193		2,792
Operating Income (Loss)	705		733		-75
Other Income and Expenses [Abstract]
Other income and expenses, net	22		18		90
Interest Expense	171		170		138
Income (Loss) From Continuing Operations Before Income Taxes	556		581		-123
Income Tax Expense (Benefit) from Continuing Operations	197		223		-73
Net income	359		358
Net Income (Loss) Attributable to Parent	359		358		-50
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges			-2		-2
Other comprehensive income (loss), net of tax			-2		-2
Comprehensive income (loss)	$359		$356		($52)
[1]	For the year ended December 31, 2012, consolidated net income of $1,782 million includes $2 million attributable to preferred shareholders of subsidiaries. Income attributable to preferred shareholders of subsidiaries is not a component of total equity and is excluded from the table above.
[2]	Net of insignificant tax expense in 2014, $17 million tax expense in 2013 and $9 million tax expense in 2012. See Note 21 for additional information.
[3]	Net of $13 million tax benefit in 2014, $20 million tax expense in 2013 and $6 million tax expense in 2012.
[4]	Net of $62 million tax expense in 2012.
[5]	Net of $46 million tax expense in 2012.
[6]	Net of $16 million tax expense in 2012.

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012
Net unrealized gains (losses) on cash flow hedges, tax	$6
Progress Energy [Member]
Reclassification of cash flow hedges to regulatory assets, tax	62
Duke Energy Progress [Member]
Reclassification of cash flow hedges to regulatory assets, tax	46
Duke Energy Florida [Member]
Reclassification of cash flow hedges to regulatory assets, tax	$16

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss)	$1,889		$2,676		$1,782
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	-124		-197		-75
Pension and OPEB adjustments	4	[1]	38	[1]	19	[1]
Net unrealized gain (loss) on cash flow hedges	-26	[2]	59	[2]	-28	[2]
Reclassification into earnings from cash flow hedges	7		1		-1
Unrealized gain (loss) on investments in available for sale securities	3		-4		14
Reclassification into earnings from available for sale securities			4		-5
Other comprehensive income (loss), net of tax	-136		-99		-76
Comprehensive Income	1,753		2,577		1,706
Less: Comprehensive Income Attributable to Noncontrolling Interests	14		5		10
Comprehensive income (loss)	$1,739		$2,572		$1,696
[1]	Net of insignificant tax expense in 2014, $17 million tax expense in 2013 and $9 million tax expense in 2012. See Note 21 for additional information.
[2]	Net of $13 million tax benefit in 2014, $20 million tax expense in 2013 and $6 million tax expense in 2012.

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthethical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension and OPEB adjustments to AOCI, tax		$17	$9
Net unrealized gains (losses) on cash flow hedges, tax	($13)	$20	$6

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current Assets [Abstract]
Cash and cash equivalents	$2,036	$1,501
Short Term Investments		44
Receivables (net of allowance for doubtful accounts)	791	1,286
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	1,973	1,719
Inventory	3,459	3,250
Assets held for sale	364
Regulatory assets, current	1,115	895
Other	1,837	1,821
Total current assets	11,575	10,516
Investments and Other Assets [Abstract]
Investments in equity method unconsolidated affiliates	358	390
Nuclear decommissioning trust funds	5,546	5,132
Goodwill	16,321	16,340
Assets held for sale	2,642	107
Other	3,008	3,432
Total investments and other assets	27,875	25,401
Property, Plant and Equipment [Abstract]
Cost	104,861	103,115
Accumulated depreciation and amortization	-34,824	-33,625
Generation Facilities To Be Retired Net	9
Net property, plant and equipment	70,046	69,490
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets, noncurrent	11,042	9,191
Other	171	181
Total regulatory assets and deferred debits	11,213	9,372
Total Assets	120,709	114,779
Current Liabilities [Abstract]
Accounts payable	2,271	2,391
Notes payable and commercial paper	2,514	839
Taxes accrued	569	551
Interest accrued	418	440
Current maturities of long-term debt	2,807	2,104
Liabilities associated with assets held for sale	262	7
Regulatory liabilities, current	204	316
Other	2,188	1,996
Total current liabilities	11,233	8,644
Long-Term debt	37,213	38,152
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	13,423	12,097
Investment tax credits	427	442
Accrued pension and other post-retirement benefit costs	1,145	1,322
Liabilities associated with assets held for sale	35	66
Asset retirement obligations	8,466	4,950
Regulatory liabilities - noncurrent	6,193	5,949
Other	1,675	1,749
Total deferred credits and other liabilities	31,364	26,575
Commitments and Contingencies
Equity [Abstract]
Common stock	1	1
Additional paid-in capital	39,405	39,365
Retained earnings	2,012	2,363
Accumulated other comprehensive (loss) income	-543	-399
Total Common Shareholders' Equity	40,875	41,330
Noncontrolling interests	24	78
Total equity	40,899	41,408
Total Liabilities and Equity	120,709	114,779
Duke Energy Carolinas [Member]
Current Assets [Abstract]
Cash and cash equivalents	13	23
Receivables (net of allowance for doubtful accounts)	129	186
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	647	673
Receivables from affiliated companies	75	75
Notes Receivable, Related Parties, Current	150	222
Inventory	1,124	1,065
Regulatory assets, current	399	295
Other	77	309
Total current assets	2,614	2,848
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	3,042	2,840
Other	959	1,000
Total investments and other assets	4,001	3,840
Property, Plant and Equipment [Abstract]
Cost	37,372	34,906
Accumulated depreciation and amortization	-12,700	-11,894
Net property, plant and equipment	24,672	23,012
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets, noncurrent	2,465	1,527
Other	42	46
Total regulatory assets and deferred debits	2,507	1,573
Total Assets	33,794	31,273
Current Liabilities [Abstract]
Accounts payable	709	701
Accounts payable to affiliated companies	154	161
Taxes accrued	146	147
Interest accrued	95	97
Current maturities of long-term debt	507	47
Regulatory liabilities, current	34	65
Other	434	393
Total current liabilities	2,079	1,611
Long-Term debt	7,584	8,089
Long-term debt payable to affiliated companies	300	300
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	5,812	5,706
Investment tax credits	204	210
Accrued pension and other post-retirement benefit costs	111	161
Asset retirement obligations	3,428	1,594
Regulatory liabilities - noncurrent	2,710	2,576
Other	642	676
Total deferred credits and other liabilities	12,907	10,923
Commitments and Contingencies
Equity [Abstract]
Member's equity	10,937	10,365
Accumulated other comprehensive (loss) income	-13	-15
Total Member's Equity	10,924	10,350
Total Liabilities and Equity	33,794	31,273
Progress Energy [Member]
Current Assets [Abstract]
Cash and cash equivalents	42	58
Receivables (net of allowance for doubtful accounts)	129	528
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	741	417
Receivables from affiliated companies	59	4
Notes Receivable, Related Parties, Current	220	75
Inventory	1,590	1,424
Regulatory assets, current	491	353
Other	1,285	726
Total current assets	4,557	3,585
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	2,503	2,292
Goodwill	3,655	3,655
Other	670	804
Total investments and other assets	6,828	6,751
Property, Plant and Equipment [Abstract]
Cost	38,650	36,480
Accumulated depreciation and amortization	-13,506	-13,098
Net property, plant and equipment	25,144	23,382
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets, noncurrent	5,408	4,155
Other	91	96
Total regulatory assets and deferred debits	5,499	4,251
Total Assets	42,028	37,969
Current Liabilities [Abstract]
Accounts payable	847	836
Accounts payable to affiliated companies	203	123
Notes payable to affiliated companies	835	1,213
Taxes accrued	114	105
Interest accrued	184	181
Current maturities of long-term debt	1,507	485
Regulatory liabilities, current	106	207
Other	1,021	896
Total current liabilities	4,817	4,046
Long-Term debt	13,247	13,630
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	4,759	3,283
Accrued pension and other post-retirement benefit costs	533	765
Asset retirement obligations	4,711	2,562
Regulatory liabilities - noncurrent	2,379	2,292
Other	406	527
Total deferred credits and other liabilities	12,788	9,429
Commitments and Contingencies
Equity [Abstract]
Common stock	0	0
Additional paid-in capital	7,467	7,467
Retained earnings	3,782	3,452
Accumulated other comprehensive (loss) income	-41	-59
Total Common Shareholders' Equity	11,208	10,860
Noncontrolling interests	-32	4
Total equity	11,176	10,864
Total Liabilities and Equity	42,028	37,969
Duke Energy Progress [Member]
Current Assets [Abstract]
Cash and cash equivalents	9	21
Receivables (net of allowance for doubtful accounts)	43	145
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	436	417
Receivables from affiliated companies	10	2
Notes Receivable, Related Parties	237
Inventory	966	853
Regulatory assets, current	287	127
Other	384	296
Total current assets	2,372	1,861
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	1,701	1,539
Other	412	443
Total investments and other assets	2,113	1,982
Property, Plant and Equipment [Abstract]
Cost	24,207	22,273
Accumulated depreciation and amortization	-9,021	-8,623
Net property, plant and equipment	15,186	13,650
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets, noncurrent	2,675	1,384
Other	34	32
Total regulatory assets and deferred debits	2,709	1,416
Total Assets	22,380	18,909
Current Liabilities [Abstract]
Accounts payable	481	420
Accounts payable to affiliated companies	120	103
Notes payable to affiliated companies		462
Taxes accrued	47	37
Interest accrued	81	70
Current maturities of long-term debt	945	174
Regulatory liabilities, current	71	63
Other	409	392
Total current liabilities	2,154	1,721
Long-Term debt	5,256	5,061
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	2,908	2,557
Accrued pension and other post-retirement benefit costs	290	321
Asset retirement obligations	3,905	1,729
Regulatory liabilities - noncurrent	1,832	1,673
Other	168	222
Total deferred credits and other liabilities	9,103	6,502
Equity [Abstract]
Common stock	2,159	2,159
Retained earnings	3,708	3,466
Total equity	5,867	5,625
Total Liabilities and Equity	22,380	18,909
Duke Energy Florida [Member]
Current Assets [Abstract]
Cash and cash equivalents	8	16
Receivables (net of allowance for doubtful accounts)	84	375
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	305
Receivables from affiliated companies	40	3
Inventory	623	571
Regulatory assets, current	203	221
Other	521	182
Total current assets	1,784	1,368
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	803	753
Other	204	252
Total investments and other assets	1,007	1,005
Property, Plant and Equipment [Abstract]
Cost	14,433	13,863
Accumulated depreciation and amortization	-4,478	-4,252
Net property, plant and equipment	9,955	9,611
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets, noncurrent	2,733	2,729
Other	39	44
Total regulatory assets and deferred debits	2,772	2,773
Total Assets	15,518	14,757
Current Liabilities [Abstract]
Accounts payable	365	333
Accounts payable to affiliated companies	70	38
Notes payable to affiliated companies	84	181
Taxes accrued	65	66
Interest accrued	47	46
Current maturities of long-term debt	562	11
Regulatory liabilities, current	35	144
Other	586	445
Total current liabilities	1,814	1,264
Long-Term debt	4,298	4,875
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	2,452	1,829
Accrued pension and other post-retirement benefit costs	221	286
Asset retirement obligations	806	833
Regulatory liabilities - noncurrent	547	618
Other	158	255
Total deferred credits and other liabilities	4,184	3,821
Commitments and Contingencies
Equity [Abstract]
Common stock	1,762	1,762
Retained earnings	3,460	3,036
Accumulated other comprehensive (loss) income	0	-1
Total equity	5,222	4,797
Total Liabilities and Equity	15,518	14,757
Duke Energy Ohio [Member]
Current Assets [Abstract]
Cash and cash equivalents	20	36
Receivables (net of allowance for doubtful accounts)	93	121
Receivables from affiliated companies	107	121
Notes Receivable, Related Parties, Current	145	57
Inventory	97	229
Assets held for sale	316
Regulatory assets, current	49	57
Other	167	270
Total current assets	994	891
Investments and Other Assets [Abstract]
Goodwill	920	920
Assets held for sale	2,605
Other	23	232
Total investments and other assets	3,548	1,152
Property, Plant and Equipment [Abstract]
Cost	7,141	11,143
Accumulated depreciation and amortization	-2,213	-2,908
Generation Facilities To Be Retired Net	9
Net property, plant and equipment	4,937	8,235
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets, noncurrent	512	471
Other	8	14
Total regulatory assets and deferred debits	520	485
Total Assets	9,999	10,763
Current Liabilities [Abstract]
Accounts payable	209	319
Accounts payable to affiliated companies	74	77
Notes payable to affiliated companies	491	43
Taxes accrued	163	167
Interest accrued	19	17
Current maturities of long-term debt	157	47
Liabilities associated with assets held for sale	246
Regulatory liabilities, current	10	27
Other	66	110
Total current liabilities	1,435	807
Long-Term debt	1,584	2,141
Long-term debt payable to affiliated companies	25
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	1,765	2,012
Accrued pension and other post-retirement benefit costs	48	58
Liabilities associated with assets held for sale	34
Asset retirement obligations	27	28
Regulatory liabilities - noncurrent	241	262
Other	166	186
Total deferred credits and other liabilities	2,281	2,546
Equity [Abstract]
Common stock	762	762
Additional paid-in capital	4,782	4,882
Retained earnings	-870	-375
Total equity	4,674	5,269
Total Liabilities and Equity	9,999	10,763
Duke Energy Indiana [Member]
Current Assets [Abstract]
Cash and cash equivalents	6	15
Receivables (net of allowance for doubtful accounts)	87	22
Receivables from affiliated companies	115	151
Notes Receivable, Related Parties, Current		96
Inventory	537	434
Regulatory assets, current	93	118
Other	326	125
Total current assets	1,164	961
Investments and Other Assets [Abstract]
Other	251	269
Total investments and other assets	251	269
Property, Plant and Equipment [Abstract]
Cost	13,034	12,489
Accumulated depreciation and amortization	-4,219	-3,913
Net property, plant and equipment	8,815	8,576
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets, noncurrent	685	717
Other	24	25
Total regulatory assets and deferred debits	709	742
Total Assets	10,939	10,548
Current Liabilities [Abstract]
Accounts payable	179	206
Accounts payable to affiliated companies	58	56
Notes payable to affiliated companies	71
Taxes accrued	54	57
Interest accrued	56	56
Current maturities of long-term debt	5	5
Regulatory liabilities, current	54	16
Other	98	88
Total current liabilities	575	484
Long-Term debt	3,636	3,641
Long-term debt payable to affiliated companies	150	150
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	1,591	1,171
Investment tax credits	139	140
Accrued pension and other post-retirement benefit costs	82	163
Asset retirement obligations	32	30
Regulatory liabilities - noncurrent	796	782
Other	90	48
Total deferred credits and other liabilities	2,730	2,334
Commitments and Contingencies
Equity [Abstract]
Common stock	1	1
Additional paid-in capital	1,384	1,384
Retained earnings	2,460	2,551
Accumulated other comprehensive (loss) income	3	3
Total equity	3,848	3,939
Total Liabilities and Equity	$10,939	$10,548

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Receivables, allowance for doubtful accounts	$17	$30
Restricted receivables, allowance for doubtful accounts	51	43
Common stock, par or stated value	$0.00	$0.00
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	707,000,000	706,000,000
Duke Energy Carolinas [Member]
Receivables, allowance for doubtful accounts	3	3
Restricted receivables, allowance for doubtful accounts	6	6
Progress Energy [Member]
Receivables, allowance for doubtful accounts	8	14
Restricted receivables, allowance for doubtful accounts	8
Common stock, par or stated value	$0.01	$0.01
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Duke Energy Progress [Member]
Receivables, allowance for doubtful accounts	7	10
Restricted receivables, allowance for doubtful accounts	5
Common stock, par or stated value	$0	$0
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares outstanding	160,000,000	160,000,000
Duke Energy Florida [Member]
Receivables, allowance for doubtful accounts	2	4
Restricted receivables, allowance for doubtful accounts	3
Common stock, par or stated value	$0	$0
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares outstanding	100	100
Duke Energy Ohio [Member]
Receivables, allowance for doubtful accounts	2	2
Common stock, par or stated value	$8.50	$8.50
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares outstanding	89,663,086	89,663,086
Duke Energy Indiana [Member]
Receivables, allowance for doubtful accounts	$1	$1
Common stock, par or stated value	$0.01	$0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares outstanding	53,913,701	53,913,701

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	$1,889	$2,676	$1,782
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	3,507	3,229	2,652
Equity component of AFUDC	-135	-157	-300
Severance expense			92
FERC mitigation costs	-15		117
Community support and charitable contributions		34	92
(Gains) losses on sales of other assets	-33	-79	-44
Impairment charges	915	400	586
Deferred income taxes	1,149	1,264	584
Equity in earnings of unconsolidated affiliates	-130	-122	-148
Voluntary opportunity cost deferral			-101
Accrued pension and other post-retirement benefit costs	108	307	239
Contributions to qualified pension plans		-250	-304
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	44	1	60
Receivables	58	-281	39
Inventory	-269	-31	-258
Other current assets	-414	-35	140
Increase (decrease) in [Abstract]
Accounts payable	-30	73	131
Taxes accrued	-14	77	-142
Other current liabilities	-201	24	295
Other assets	16	-384	-129
Other liabilities	141	-364	-139
Net cash provided by (used in) operating activities	6,586	6,382	5,244
Net Income (Loss) Attributable to Parent	1,883	2,665	1,768
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	-5,384	-5,526	-5,501
Investment expenditures	-90	-81	-6
Acquisitions	-54		-451
Cash acquired from the merger with Progress Energy			71
Purchases of available-for-sale securities	-4,110	-6,142	-4,719
Proceeds from sales and maturities of available-for-sale securities	4,133	6,315	4,537
Net proceeds from the sales of equity investments and other assets, and sales of and collections on notes receivable	179	277	212
Change in Restricted Cash	9	167	-414
Other	-56	12	74
Net cash (used in) provided by investing activities	-5,373	-4,978	-6,197
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	2,914	3,601	4,170
Proceeds from the issuance of common stock related to employee benefit plans	25	9	23
Payments for the redemption of long-term debt	-3,037	-2,761	-2,498
Payments for the redemption of preferred stock		-96
Proceeds from issuance of short-term debt with original maturities greater than 90 days	1,066
Payments for the redemption of short-term debt with original maturities greater than 90 days	-564
Notes payable and commercial paper	1,186	93	278
Distributions to noncontrolling interests	-65	-15	-25
Contributions from noncontrolling Interests		9	76
Dividends paid	-2,234	-2,188	-1,752
Other	31	21	-5
Net cash provided by (used in) financing activities	-678	-1,327	267
Net increase (decrease) in cash and cash equivalents	535	77	-686
Cash and cash equivalents at beginning of period	1,501	1,424	2,110
Cash and cash equivalents at end of period	2,036	1,501	1,424
Supplemental Disclosures [Abstract]
Cash paid for interest, net of amount capitalized	1,659	1,665	1,032
Cash paid for (received from) income taxes	158	-202	72
Merger with Progress Energy [Abstract]
Fair value of assets acquired			48,944
Liabilities assumed			30,873
Issuance of common stock			18,071
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	664	594	684
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	1,072	976
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,273	1,167	1,143
Equity component of AFUDC	-91	-91	-154
FERC mitigation costs	3		46
Community support and charitable contributions		14	56
(Gains) losses on sales of other assets			-12
Deferred income taxes	376	534	479
Voluntary opportunity cost deferral			-101
Accrued pension and other post-retirement benefit costs	22	38	41
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions		-9
Receivables	48	-12	22
Receivables from affiliated companies		-72	-1
Inventory	-60	-9	-128
Other current assets	-236	-1	46
Increase (decrease) in [Abstract]
Accounts payable	10	58	-51
Accounts payable to affiliated companies	-7	33	-28
Taxes accrued	-15	4	-12
Other current liabilities	-10	-40	165
Other assets	17	-102	-117
Other liabilities	-22	-77	-126
Net cash provided by (used in) operating activities	2,380	2,411	2,133
Net Income (Loss) Attributable to Parent	1,072	976	865
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	-1,879	-1,695	-1,908
Purchases of available-for-sale securities	-2,064	-2,405	-2,481
Proceeds from sales and maturities of available-for-sale securities	2,044	2,363	2,445
Notes receivable from affiliated companies	72	160	541
Other	-18	-24	-12
Net cash (used in) provided by investing activities	-1,845	-1,601	-1,415
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt		100	645
Payments for the redemption of long-term debt	-45	-405	-1,177
Dividends or distributions to parent	-500	-499	-450
Other		-2	-6
Net cash provided by (used in) financing activities	-545	-806	-988
Net increase (decrease) in cash and cash equivalents	-10	4	-270
Cash and cash equivalents at beginning of period	23	19	289
Cash and cash equivalents at end of period	13	23	19
Supplemental Disclosures [Abstract]
Cash paid for interest, net of amount capitalized	388	336	385
Cash paid for (received from) income taxes	305	-7	-38
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	194	199	194
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	874	675	407
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,313	1,041	897
Equity component of AFUDC	-26	-50	-106
Severance expense			38
FERC mitigation costs	-18		71
Community support and charitable contributions		20	36
(Gains) losses on sales of other assets	-6	2	-16
Impairment charges	2	380	146
Deferred income taxes	1,014	616	263
Amount to be refunded to customers			100
Accrued pension and other post-retirement benefit costs	27	172	179
Contributions to qualified pension plans		-250	-346
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	12	55	7
Receivables	-31	-148	49
Receivables from affiliated companies	-56	11	-15
Inventory	-101	17	-71
Other current assets	-934	-156	2
Increase (decrease) in [Abstract]
Accounts payable	6	-81	175
Accounts payable to affiliated companies	80	93	30
Taxes accrued	-20	22	25
Other current liabilities	-144	61	81
Other assets	-14	-243	-25
Other liabilities	-12	-115	-87
Net cash provided by (used in) operating activities	1,966	2,122	1,840
Net Income (Loss) Attributable to Parent	869	672	400
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	-1,940	-2,490	-2,366
Purchases of available-for-sale securities	-1,689	-2,558	-1,374
Proceeds from sales and maturities of available-for-sale securities	1,652	2,513	1,325
Notes receivable from affiliated companies	-145	-75
Change in Restricted Cash			24
Other	-44	13	109
Net cash (used in) provided by investing activities	-2,166	-2,597	-2,282
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	1,572	845	2,074
Proceeds from the issuance of common stock related to employee benefit plans			6
Payments for the redemption of long-term debt	-931	-1,196	-962
Payments for the redemption of preferred stock		-96
Proceeds from issuance of short-term debt with original maturities greater than 90 days			65
Payments for the redemption of short-term debt with original maturities greater than 90 days			-65
Notes payable and commercial paper			-671
Notes payable to affiliated companies	-378	758	455
Distributions to noncontrolling interests	-37	-3	-7
Dividends paid			-445
Other	-42	-6	-7
Net cash provided by (used in) financing activities	184	302	443
Net increase (decrease) in cash and cash equivalents	-16	-173	1
Cash and cash equivalents at beginning of period	58	231	230
Cash and cash equivalents at end of period	42	58	231
Supplemental Disclosures [Abstract]
Cash paid for interest, net of amount capitalized	664	678	784
Cash paid for (received from) income taxes	141	-167	-4
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	294	255	375
Asset retirement obligation additions for spent nuclear fuel disposal related to the Progress Energy merger			837
Capital expenditures financed through capital leases			140
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	467	500	272
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	761	685	676
Equity component of AFUDC	-25	-42	-69
Severance expense			18
FERC mitigation costs	-18		71
Community support and charitable contributions		20	36
(Gains) losses on sales of other assets	-3	-1	-1
Impairment charges		22
Deferred income taxes	455	368	164
Accrued pension and other post-retirement benefit costs	-7	72	70
Contributions to qualified pension plans		-63	-141
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	13	-9	-25
Receivables	78	-88	2
Receivables from affiliated companies	-8	3	-4
Inventory	-65	-26	-58
Other current assets	-416	-39	-24
Increase (decrease) in [Abstract]
Accounts payable	27	-18	149
Accounts payable to affiliated companies	17	27	47
Taxes accrued	10	15	-5
Other current liabilities	-68	-86	23
Other assets	48	-74	-28
Other liabilities	-21	-78	-6
Net cash provided by (used in) operating activities	1,245	1,188	1,167
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	-1,241	-1,567	-1,525
Purchases of available-for-sale securities	-499	-901	-582
Proceeds from sales and maturities of available-for-sale securities	458	856	532
Notes receivable from affiliated companies	-237
Other	-12	4	91
Net cash (used in) provided by investing activities	-1,531	-1,608	-1,484
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	1,347	845	988
Payments for the redemption of long-term debt	-379	-451	-502
Payments for the redemption of preferred stock		-62	0
Notes payable and commercial paper			-188
Notes payable to affiliated companies	-462	98	333
Dividends or distributions to parent	-225		-310
Dividends paid on preferred stock			-3
Other	-7	-7	-3
Net cash provided by (used in) financing activities	274	423	315
Net increase (decrease) in cash and cash equivalents	-12	3	-2
Cash and cash equivalents at beginning of period	21	18	20
Cash and cash equivalents at end of period	9	21	18
Supplemental Disclosures [Abstract]
Cash paid for interest, net of amount capitalized	220	217	249
Cash paid for (received from) income taxes	81	-94	19
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	194	166	232
Asset retirement obligation additions for spent nuclear fuel disposal related to the Progress Energy merger			698
Capital expenditures financed through capital leases			140
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	548	325	266
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	550	335	197
Equity component of AFUDC		-8	-37
Severance expense			6
(Gains) losses on sales of other assets	-1	-1	-2
Impairment charges	2	358	146
Deferred income taxes	400	368	142
Amount to be refunded to customers			100
Accrued pension and other post-retirement benefit costs	29	79	71
Contributions to qualified pension plans		-133	-128
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	-9	55	73
Receivables	-33	-44	37
Receivables from affiliated companies	-37	17	-13
Inventory	-36	42	-13
Other current assets	-269	-109	22
Increase (decrease) in [Abstract]
Accounts payable	18	-22	21
Accounts payable to affiliated companies	32	-6	30
Taxes accrued	-31	18	15
Other current liabilities	-80	159	51
Other assets	-59	-154	8
Other liabilities	-58	-74	-94
Net cash provided by (used in) operating activities	966	1,205	898
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	-699	-915	-809
Purchases of available-for-sale securities	-1,189	-1,656	-791
Proceeds from sales and maturities of available-for-sale securities	1,195	1,658	791
Notes receivable from affiliated companies		207	-207
Other	-31		16
Net cash (used in) provided by investing activities	-724	-706	-1,000
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt	225		642
Payments for the redemption of long-term debt	-252	-435	-10
Payments for the redemption of preferred stock		-34
Proceeds from issuance of short-term debt with original maturities greater than 90 days			65
Payments for the redemption of short-term debt with original maturities greater than 90 days			-65
Notes payable and commercial paper			-233
Notes payable to affiliated companies	-97	181	-8
Dividends or distributions to parent	-124	-325	-170
Dividends paid on preferred stock			-2
Other	-2	-1	-2
Net cash provided by (used in) financing activities	-250	-614	217
Net increase (decrease) in cash and cash equivalents	-8	-115	115
Cash and cash equivalents at beginning of period	16	131	16
Cash and cash equivalents at end of period	8	16	131
Supplemental Disclosures [Abstract]
Cash paid for interest, net of amount capitalized	203	201	266
Cash paid for (received from) income taxes	59	-84	24
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	100	88	139
Asset retirement obligation additions for spent nuclear fuel disposal related to the Progress Energy merger			139
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	-495	102	175
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	258	357	342
Equity component of AFUDC	-4	-1	-6
(Gains) losses on sales of other assets	-1	-5	-7
Impairment charges	941	5	2
Deferred income taxes	-219	98	61
Accrued pension and other post-retirement benefit costs	8	17	11
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions	27	17	-5
Receivables	-56	-15	29
Receivables from affiliated companies	14	-39	61
Inventory	8	-3	15
Other current assets	-5	-1	-62
Increase (decrease) in [Abstract]
Accounts payable	27	13	5
Accounts payable to affiliated companies	-3	15	-22
Taxes accrued	-9	1	-24
Other current liabilities	27	14	-21
Other assets	-4	-6	6
Other liabilities	-33	-73	-116
Net cash provided by (used in) operating activities	481	496	444
Net Income (Loss) Attributable to Parent	-495	102	175
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	-322	-434	-514
Net proceeds from the sales of equity investments and other assets, and sales of and collections on notes receivable		11	82
Notes receivable from affiliated companies	-88	-56	400
Other	-12	1	6
Net cash (used in) provided by investing activities	-422	-478	-26
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt		450
Payments for the redemption of long-term debt	-449	-258	-556
Notes payable to affiliated companies	473	-202	245
Dividends or distributions to parent	-100		-175
Other	1	-3
Net cash provided by (used in) financing activities	-75	-13	-486
Net increase (decrease) in cash and cash equivalents	-16	5	-68
Cash and cash equivalents at beginning of period	36	31	99
Cash and cash equivalents at end of period	20	36	31
Supplemental Disclosures [Abstract]
Cash paid for interest, net of amount capitalized	76	71	93
Cash paid for (received from) income taxes	-5	9	18
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	24	27	31
Transfer of Vermillion Generating Station			28
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES [Abstract]
Net income	359	358
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Depreciation, amortization and accretion (including amortization of nuclear fuel)	416	346	393
Equity component of AFUDC	-14	-15	-84
Impairment charges			579
Deferred income taxes	308	304	-74
Accrued pension and other post-retirement benefit costs	16	25	15
(Increase) decrease in [Abstract]
Net realized and unrealized mark-to-market and hedging transactions		-30
Receivables	-35	3	6
Receivables from affiliated companies	36	-47	52
Inventory	-103	-53	-50
Other current assets	-8	-40	-25
Increase (decrease) in [Abstract]
Accounts payable	-41	32	18
Accounts payable to affiliated companies	2	-4	-12
Taxes accrued	-32	-30	-27
Other current liabilities	5	-5	6
Other assets	-21	-16	6
Other liabilities	17	-84	-37
Net cash provided by (used in) operating activities	905	744	716
Net Income (Loss) Attributable to Parent	359	358	-50
CASH FLOWS FROM INVESTING ACTIVITIES [Abstract]
Capital expenditures	-625	-545	-718
Purchases of available-for-sale securities	-20	-11	-17
Proceeds from sales and maturities of available-for-sale securities	16	7	18
Notes receivable from affiliated companies	96	-96
Other	4	-3	-1
Net cash (used in) provided by investing activities	-529	-648	-718
CASH FLOWS FROM FINANCING ACTIVITIES [Abstract]
Proceeds from the issuance of long-term debt		498	250
Payments for the redemption of long-term debt	-5	-405	-7
Notes payable to affiliated companies	71	-81	-219
Dividends or distributions to parent	-450	-125
Other	-1	-4	-2
Net cash provided by (used in) financing activities	-385	-117	22
Net increase (decrease) in cash and cash equivalents	-9	-21	20
Cash and cash equivalents at beginning of period	15	36	16
Cash and cash equivalents at end of period	6	15	36
Supplemental Disclosures [Abstract]
Cash paid for interest, net of amount capitalized	169	194	130
Cash paid for (received from) income taxes	-61	46	57
Significant Non-cash Transactions [Abstract]
Accrued capital expenditures	87	73	67
Transfer of Vermillion Generating Station			$26

Consolidated_Statements_of_Equ

Consolidated Statements of Equity (USD $)		Total		Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]		Foreign Currency Adjustments [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]	Net Gains (Losses) on Available for Sale Securities [Member]	Pension And OPEB Related Adjustments To AOCI [Member]	Common Stockholders' Equity [Member]		Noncontrolling Interest [Member]		Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member]	Progress Energy [Member]	Progress Energy [Member]	Progress Energy [Member]	Progress Energy [Member]	Progress Energy [Member]	Progress Energy [Member]	Progress Energy [Member]	Progress Energy [Member]	Progress Energy [Member]	Duke Energy Progress [Member]	Duke Energy Progress [Member]	Duke Energy Progress [Member]	Duke Energy Progress [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member]	Duke Energy Ohio [Member]	Duke Energy Ohio [Member]	Duke Energy Ohio [Member]	Duke Energy Ohio [Member]	Duke Energy Ohio [Member]	Duke Energy Indiana [Member]	Duke Energy Indiana [Member]	Duke Energy Indiana [Member]	Duke Energy Indiana [Member]	Duke Energy Indiana [Member]
In Millions, except Share data, unless otherwise specified																	Members Equity [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]	Net Gains (Losses) on Available for Sale Securities [Member]		Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]	Net Gains (Losses) on Available for Sale Securities [Member]	Pension And OPEB Related Adjustments To AOCI [Member]	Common Stockholders' Equity [Member]	Noncontrolling Interest [Member]		Common Stock [Member]	Retained Earnings [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]		Common Stock [Member]	Retained Earnings [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]		Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Pension And OPEB Related Adjustments To AOCI [Member]		Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]
Beginning Member's Equity at Dec. 31, 2011																$9,454	$9,473	($17)	($2)
Balance at Dec. 31, 2011		22,865		1	21,132	1,873		-45	-71	-9	-109	22,772		93						10,025	7,418	16	2,752	-142	0	-23	10,021	4	5,088	2,148	3,011	-71	4,675	1,757	2,945	-27	5,167	762	5,085	-652	-28	3,734	1	1,358	2,368	7
Balance (in shares) at Dec. 31, 2011		445,000,000
Net Income (Loss) Attributable to Parent		1,768														865	865			400																	175					-50			-50
Net income		1,782				1,768	[1]					1,768	[1]	12	[1]					407									272		272		266		266		175			175
Net income (loss) available to common stockholders		1,780	[1]																										269				264
Net Income Loss Including Portion Attributable To Noncontrolling Interest Equity Statement	[2]																			403			400				400	3
Other comprehensive income (loss), net of tax		-76						-71	-29	9	19	-72		-4		3		2	1	98				100		-2	98		71			71	27			27	27				27	-2				-2
Distribution to parent																-450	-450
Common stock issuances, including dividend reinvestment and employee benefits (in shares)		1,000,000
Common stock issuances, including dividend reinvestment and employee benefits		76			76							76								31	18	13					31
Common stock issued in connection with the Progress Energy Merger (in shares)		258,000,000
Common stock issued in connection with the Progress Energy Merger		18,071			18,071							18,071
Stock-based compensation expense																													11	11			5	5
Transfer of Vermillion Generating Station																																					-28		-28			-26		-26
Common stock dividends		-1,752				-1,752						-1,752								-369			-369				-369		-310		-310		-170		-170		-175		-175
Preferred stock dividends at stated rates																													-3		-3		-2		-2
Contributions from noncontrolling Interests		76
Deconsolidation of DS Cornerstone, LLC		-82												-82
Contribution from noncontrolling interest in DS Cornerstone, LLC		76												76
Changes in noncontrolling interest in subsidiaries		-17	[3]											-17	[3]					-2								-2
Recapitalization for merger with Duke Energy																					-7,436	7,436
Tax dividend																													-2		-2		-2		-2
Noncontrolling Interest Other Transactions																				-1								-1
Total Member's Equity																9,872	9,888	-15	-1
Notes To Reconciliation Of Total Equity [Details]
Net income attributable to preferred shareholders																				4
Balance at Dec. 31, 2012		40,941		1	39,279	1,889		-116	-100	0	-90	40,863		78						10,185	0	7,465	2,783	-42	0	-25	10,181	4	5,127	2,159	2,968	0	4,799	1,762	3,037	0	5,166	762	4,882	-477	-1	3,708	1	1,384	2,318	5
Balance (in shares) at Dec. 31, 2012				704,000,000
Beginning Member's Equity at Dec. 31, 2012																9,872
Net Income (Loss) Attributable to Parent		634																		153
Net income		634														244				154									110				110				-21					90
Balance at Mar. 31, 2013
Beginning Member's Equity at Dec. 31, 2012																9,872	9,888	-15	-1
Balance at Dec. 31, 2012		40,941		1	39,279	1,889		-116	-100		-90	40,863		78						10,185		7,465	2,783	-42	0	-25	10,181	4	5,127		2,968		4,799		3,037	0	5,166	762		-477	-1	3,708	1		2,318	5
Balance (in shares) at Dec. 31, 2012				704,000,000
Net Income (Loss) Attributable to Parent		2,665														976	976			672																	102					358			358
Net income		2,676				2,665						2,665		11		976				675									500		500		325		325		102			102		358
Net income (loss) available to common stockholders		2,676																											500				325
Net Income Loss Including Portion Attributable To Noncontrolling Interest Equity Statement																				675			672				672	3
Other comprehensive income (loss), net of tax		-99						-191	60		38	-93		-6		1		1	0	8				-1		9	8		0				-1			-1	1				1	-2				-2
Distribution to parent																-499	-499
Common stock issuances, including dividend reinvestment and employee benefits (in shares)		2,000,000
Common stock issuances, including dividend reinvestment and employee benefits		86			86							86
Common stock dividends		-2,188				-2,188						-2,188																					-325		-325							-125			-125
Premium on the redemption of preferred stock of subsidiaries		-3				-3						-3								-3			-3				-3		-2		-2		-1		-1
Contributions from noncontrolling Interests		9												9
Changes in noncontrolling interest in subsidiaries		-14	[3]											-14	[3]					-3								-3
Other additional paid in capital adjustments																				2		2					2
Noncontrolling Interest Other Transactions																												0
Total Member's Equity																10,350	10,365	-14	-1
Notes To Reconciliation Of Total Equity [Details]
Net income attributable to preferred shareholders		2
Balance at Dec. 31, 2013		41,408			39,365	2,363		-307	-40		-52	41,330		78						10,864	0	7,467	3,452	-43		-16	10,860	4	5,625	2,159	3,466	0	4,797	1,762	3,036	-1	5,269	762		-375	0	3,939	1	1,384	2,551	3
Balance (in shares) at Dec. 31, 2013		706,000,000																		100									160,000,000				100				89,663,086					53,913,701
Beginning Member's Equity at Sep. 30, 2013
Net Income (Loss) Attributable to Parent		688																		195
Net income		692														209				196									138				75				6					82
Total Member's Equity																10,350
Balance at Dec. 31, 2013		41,408																		10,864	0								5,625	2,159		0	4,797	1,762			5,269	762				3,939	1	1,384
Balance (in shares) at Dec. 31, 2013		706,000,000																		100									160,000,000				100				89,663,086					53,913,701
Beginning Member's Equity at Dec. 31, 2013																10,350
Net Income (Loss) Attributable to Parent		-97																		202
Net income		-93														286				203									133				108				-890					113
Balance at Mar. 31, 2014
Beginning Member's Equity at Dec. 31, 2013																10,350	10,365	-14	-1
Balance at Dec. 31, 2013		41,408		1	39,365	2,363		-307	-40		-52	41,330		78						10,864	0		3,452	-43	0	-16	10,860	4	5,625	2,159	3,466	0	4,797	1,762	3,036	-1	5,269	762	4,882	-375		3,939	1	1,384	2,551
Balance (in shares) at Dec. 31, 2013		706,000,000		706,000,000																100									160,000,000				100				89,663,086					53,913,701
Net Income (Loss) Attributable to Parent		1,883														1,072	1,072			869																	-495					359			359
Net income		1,889				1,883						1,883		6		1,072				874									467		467		548		548		-495			-495		359
Net income (loss) available to common stockholders																													467				548
Net Income Loss Including Portion Attributable To Noncontrolling Interest Equity Statement																				874			869				869	5
Other comprehensive income (loss), net of tax		-136						-132	-19	3	4	-144		8		2		2	0	18				8	1	9	18		0				1			1
Distribution to parent																-500	-500
Common stock issuances, including dividend reinvestment and employee benefits (in shares)				1,000,000
Common stock issuances, including dividend reinvestment and employee benefits		40			40							40
Common stock dividends		-2,234				-2,234						-2,234																	-225		-225		-124		-124		-100		-100			-450			-450
Changes in noncontrolling interest in subsidiaries		-65	[3]											-65	[3]					-37								-37
Other additional paid in capital adjustments		-3
Stockholders' Equity, Other																				-539			-539				-539
Noncontrolling Interest Other Transactions														-3						-4								-4
Total Member's Equity																10,924	10,937	-12	-1
Balance at Dec. 31, 2014		40,899		1	39,405	2,012		-439	-59	3	-48	40,875		24						11,176	0	7,467	3,782	-35	1	-7	11,208	-32	5,867	2,159	3,708	0	5,222	1,762	3,460	0	4,674	762	4,782	-870	0	3,848	1	1,384	2,460	3
Balance (in shares) at Dec. 31, 2014		707,000,000		707,000,000																100									160,000,000				100				89,663,086					53,913,701
Beginning Member's Equity at Sep. 30, 2014
Net Income (Loss) Attributable to Parent		97																		136
Net income		100														139				139									76				93				64					58
Total Member's Equity																10,924
Balance at Dec. 31, 2014		$40,899																		$11,176	$0	$7,467							$5,867	$2,159		$0	$5,222	$1,762			$4,674	$762			$0	$3,848	$1	$1,384		$3
Balance (in shares) at Dec. 31, 2014		707,000,000																		100									160,000,000				100				89,663,086					53,913,701
[1]	For the year ended December 31, 2012, consolidated net income of $1,782 million includes $2 million attributable to preferred shareholders of subsidiaries. Income attributable to preferred shareholders of subsidiaries is not a component of total equity and is excluded from the table above.
[2]	For the year ended December 31, 2012, consolidated net income of $407 million included $4 million attributable to preferred shareholders of subsidiaries. Income attributable to preferred shareholders of subsidiaries is not a component of total equity and is excluded from the table above.
[3]	This decrease primarily relates to cash distributions to noncontrolling interests

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Index to Combined Notes To Consolidated Financial Statements
	The notes to the consolidated financial statements are a combined presentation. The following list indicates the registrants to which the notes apply.
		Applicable Notes
	Registrant	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25
	Duke Energy Corporation	•	•	•	•	•	•	•	•	•	•	•	•		•	•	•	•	•	•	•	•	•	•	•	•
	Duke Energy Carolinas, LLC	•	•	•	•	•	•		•	•	•	•		•	•	•	•	•		•	•	•	•	•	•	•
	Progress Energy, Inc.	•	•	•	•	•	•	•	•	•	•	•		•	•	•	•	•		•	•	•	•	•	•	•
	Duke Energy Progress, Inc.	•	•	•	•	•	•		•	•	•	•		•	•	•	•	•		•	•	•	•	•	•	•
	Duke Energy Florida, Inc.	•	•	•	•	•	•	•	•	•	•	•		•	•	•	•	•		•	•	•	•	•	•	•
	Duke Energy Ohio, Inc.	•	•	•	•	•	•		•	•	•	•		•	•		•	•		•	•	•	•	•	•	•
	Duke Energy Indiana, Inc.	•	•	•	•	•	•		•	•	•	•		•	•	•	•	•		•	•	•	•	•	•	•
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Nature of Operations and Basis of Consolidation
	Duke Energy Corporation (collectively with its subsidiaries, Duke Energy) is an energy company headquartered in Charlotte, North Carolina, subject to regulation by the Federal Energy Regulatory Commission (FERC). Duke Energy operates in the United States (U.S.) and Latin America primarily through its direct and indirect subsidiaries. Duke Energy’s subsidiaries include its subsidiary registrants, Duke Energy Carolinas, LLC (Duke Energy Carolinas); Progress Energy, Inc. (Progress Energy); Duke Energy Progress, Inc. (Duke Energy Progress); Duke Energy Florida, Inc. (Duke Energy Florida); Duke Energy Ohio, Inc. (Duke Energy Ohio) and Duke Energy Indiana, Inc. (Duke Energy Indiana). When discussing Duke Energy’s consolidated financial information, it necessarily includes the results of its six separate subsidiary registrants (collectively referred to as the Subsidiary Registrants), which, along with Duke Energy, are collectively referred to as the Duke Energy Registrants (Duke Energy Registrants).
	On July 2, 2012, Duke Energy merged with Progress Energy, with Duke Energy continuing as the surviving corporation. Progress Energy became a subsidiary of Duke Energy and Progress Energy’s regulated utility subsidiaries, Duke Energy Progress (formerly Carolina Power & Light Company d/b/a Progress Energy Carolinas, Inc.) and Duke Energy Florida (formerly Florida Power Corporation d/b/a Progress Energy Florida, Inc.), became indirect subsidiaries of Duke Energy. Duke Energy’s consolidated financial statements include Progress Energy, Duke Energy Progress and Duke Energy Florida activity beginning July 2, 2012. The impacts of acquisition accounting from Progress Energy’s merger with Duke Energy were recorded by Duke Energy and were not reflected on the financial statements of Progress Energy, Duke Energy Progress and Duke Energy Florida. See Note 2 for additional information regarding the merger. On July 2, 2012, just prior to the close of the merger, Duke Energy executed a one-for-three reverse stock split with respect to the issued and outstanding shares of Duke Energy common stock. All per-share amounts included in this Form 10-K are presented as if the stock split had been effective from the beginning of the earliest period presented.
	On August 21, 2014, Duke Energy Commercial Enterprises, Inc., an indirect wholly owned subsidiary of Duke Energy Corporation, and Duke Energy SAM, LLC, a wholly owned subsidiary of Duke Energy Ohio, entered into a purchase and sale agreement (PSA) with a subsidiary of Dynegy Inc. (Dynegy) whereby Dynegy will acquire Duke Energy Ohio’s nonregulated Midwest generation business and Duke Energy Retail Sales LLC (Disposal Group). The results of operations of the nonregulated Midwest generation business have been classified as Discontinued Operations on the Consolidated Statements of Operations for the current and prior periods presented. Duke Energy has elected to present cash flows of discontinued operations combined with cash flows of continuing operations. Unless otherwise noted, the notes to these consolidated financial statements exclude amounts related to discontinued operations for all periods presented, assets held for sale and liabilities associated with assets held for sale as of December 31, 2014. See Note 2 for additional information.
	The information in these combined notes relate to each of the Duke Energy Registrants as noted in the Index to the Combined Notes to Consolidated Financial Statements. However, none of the registrants makes any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself.
	These Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries where the respective Duke Energy Registrants have control. These Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities.
	Duke Energy Carolinas is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Carolinas is subject to the regulatory provisions of the North Carolina Utilities Commission (NCUC), Public Service Commission of South Carolina (PSCSC), U.S. Nuclear Regulatory Commission (NRC) and FERC. Substantially all of Duke Energy Carolinas’ operations qualify for regulatory accounting.
	Progress Energy is a public utility holding company headquartered in Raleigh, North Carolina, subject to regulation by the FERC. Progress Energy conducts operations through its wholly owned subsidiaries, Duke Energy Progress and Duke Energy Florida. Substantially all of Progress Energy’s operations qualify for regulatory accounting.
	Duke Energy Progress is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Progress is subject to the regulatory provisions of the NCUC, PSCSC, NRC and FERC. Substantially all of Duke Energy Progress’ operations qualify for regulatory accounting.
	Duke Energy Florida is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Florida. Duke Energy Florida is subject to the regulatory provisions of the Florida Public Service Commission (FPSC), NRC and FERC. Substantially all of Duke Energy Florida’s operations qualify for regulatory accounting.
	Duke Energy Ohio is a regulated public utility primarily engaged in the transmission and distribution of electricity in Ohio and Kentucky, in the generation business in Kentucky, and the transportation and sale of natural gas in portions of Ohio and Kentucky. Operations in Kentucky are conducted through its wholly owned subsidiary, Duke Energy Kentucky, Inc. (Duke Energy Kentucky). Duke Energy Ohio conducts competitive auctions for retail electricity supply in Ohio whereby the energy price is recovered from retail customers. References herein to Duke Energy Ohio include Duke Energy Ohio and its subsidiaries, unless otherwise noted. Duke Energy Ohio is subject to the regulatory provisions of the Public Utilities Commission of Ohio (PUCO), Kentucky Public Service Commission (KPSC) and FERC. Duke Energy Ohio applies regulatory accounting to a portion of its operations. Duke Energy has agreed to sell Duke Energy Ohio's nonregulated Midwest generation business, which sells power into wholesale energy markets, to Dynegy. See Note 2 for additional information.
	Duke Energy Indiana is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Indiana. Duke Energy Indiana is subject to the regulatory provisions of the Indiana Utility Regulatory Commission (IURC) and FERC. Substantially all of Duke Energy Indiana’s operations qualify for regulatory accounting.
	Certain prior year amounts have been reclassified to conform to the current year presentation.
	Other Current and Non-Current Assets and Liabilities
	Other within Current Assets includes the current portion of deferred tax assets, which are disclosed in Note 22. Additionally, the following are included in Other within Current Assets or Current Liabilities in the Consolidated Balance Sheets of the Duke Energy Registrants at December 31, 2014 and 2013. The amounts presented exceeded 5 percent of current assets or 5 percent of current liabilities unless otherwise noted.
				December 31,
	(in millions)	Location		2014				2013
	Duke Energy
	Accrued compensation	Current Liabilities		$	638			$	621
	Duke Energy Carolinas
	Accrued compensation	Current Liabilities		$	216			$	198
	Collateral liabilities	Current Liabilities		128				120
	Progress Energy
	Income taxes receivable(b)	Current Assets		$	718			$	119
	Customer deposits	Current Liabilities		360				349
	Accrued compensation(a)	Current Liabilities		174				214
	Derivative liabilities(b)	Current Liabilities		271				—
	Duke Energy Progress
	Income taxes receivable(b)	Current Assets		$	272			$	15
	Customer deposits	Current Liabilities		135				129
	Accrued compensation	Current Liabilities		116				121
	Derivative liabilities(b)	Current Liabilities		108				38
	Duke Energy Florida
	Income taxes receivable(b)	Current Assets		$	177			$	65
	Customer deposits	Current Liabilities		225				220
	Accrued compensation(a)	Current Liabilities		57				65
	Derivative liabilities(b)	Current Liabilities		163				—
	Duke Energy Ohio
	Collateral assets(a)	Current Assets		$	13			$	122
	Duke Energy Indiana
	Income taxes receivable	Current Assets		$	98			$	56
	Accrued compensation(a)	Current Liabilities		25				25
	Collateral liabilities	Current Liabilities		43				40
	(a) Does not exceed 5 percent of total current assets or liabilities, as appropriate, on the Consolidated Balance Sheets at December 31, 2014.
	(b) Does not exceed 5 percent of total current assets or liabilities, as appropriate, on the Consolidated Balance Sheets at December 31, 2013.
	Preferred Stock
	In March 2013, Duke Energy Progress and Duke Energy Florida redeemed all series of their outstanding preferred stock at prices ranging from $101.00 to $110.00 per share for Duke Energy Progress and $101.00 to $104.25 per share for Duke Energy Florida plus accrued dividends for all series. Duke Energy Progress and Duke Energy Florida redeemed the shares for $62 million and $34 million, respectively.
	Discontinued Operations
	For the year ended December 31, 2014, Duke Energy’s Loss from Discontinued Operations, net of tax was primarily related to a write-down of the carrying amount of the assets to the estimated fair value of the Disposal Group, based on the transaction price included in the PSA, and the operations of the Disposal Group. For the years ended December 31, 2013 and 2012, Duke Energy’s Income From Discontinued Operations, net of tax was primarily related to the operations of the Disposal Group. See Note 2 for additional information.
	For the years ended December 31, 2014, 2013 and 2012. Progress Energy’s (Loss) Income From Discontinued Operations, net of tax was primarily due to tax impacts related to prior sales of diversified businesses.
	Amounts Attributable to Controlling Interests
	The following table presents Net Income Attributable to Duke Energy Corporation for continuing operations and discontinued operations.
	Years ended December 31,
	2014							2013							2012
(in millions)	Duke Energy			Progress Energy				Duke Energy			Progress Energy				Duke Energy			Progress Energy
Income from Continuing Operations	$	2,465		$	880			$	2,590		$	659			1,611			355
Income of Continuing Operations Attributable to Noncontrolling Interests	14			5				16			3				18			7
Income from Continuing Operations Attributable to Duke Energy Corporation	$	2,451		$	875			$	2,574		$	656			$	1,593		$	348
(Loss) Income From Discontinued Operations, net of tax	$	(576	)	$	(6	)		$	86		$	16			171			52
Loss of Discontinued Operations attributable to Noncontrolling Interests, net of tax	(8		)	—				(5		)	—				(4		)	—
(Loss) Income From Discontinued Operations Attributable to Duke Energy Corporation, net of tax	$	(568	)	$	(6	)		$	91		$	16			$	175		$	52
Net Income	$	1,889		$	874			$	2,676		$	675			$	1,782		$	407
Net Income Attributable to Noncontrolling Interest	6			5				11			3				14			7
Net Income Attributable to Duke Energy Corporation	$	1,883		$	869			$	2,665		$	672			$	1,768		$	400
Significant Accounting Policies
Use of Estimates
In preparing financial statements that conform to generally accepted accounting principles (GAAP) in the U.S., the Duke Energy Registrants must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses, and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.
Regulatory Accounting
The majority of the Duke Energy Registrants’ operations are subject to price regulation for the sale of electricity and gas by state utility commissions or FERC. When prices are set on the basis of specific costs of the regulated operations and an effective franchise is in place such that sufficient gas or electric services can be sold to recover those costs, the Duke Energy Registrants apply regulatory accounting. Regulatory accounting changes the timing of the recognition of costs or revenues relative to a company that does not apply regulatory accounting. As a result, Regulatory assets and Regulatory liabilities are recognized on the Consolidated Balance Sheets. Regulatory assets and liabilities are amortized consistent with the treatment of the related cost in the ratemaking process. See Note 4 for further information.
Regulated Fuel Costs and Purchased Power
The Duke Energy Registrants utilize cost-tracking mechanisms, commonly referred to as fuel adjustment clauses. These clauses allow for the recovery of fuel and fuel-related costs and portions of purchased power costs through surcharges on customer rates. The difference between the costs incurred and the surcharge revenues is recorded as an adjustment to Fuel Operating Revenues – Regulated electric on the Consolidated Statements of Operations with an off-setting impact on regulatory assets or liabilities.
Cash and Cash Equivalents
All highly liquid investments with maturities of three months or less at the date of acquisition are considered cash equivalents. At December 31, 2014, $1,680 million of Duke Energy’s total cash and cash equivalents is held by entities domiciled in foreign jurisdictions. During the fourth quarter of 2014, Duke Energy declared a taxable dividend of historical foreign earnings in the form of notes payable that will result in the repatriation of approximately $2.7 billion in cash held and expected to be generated by International Energy over a period of up to 8 years. See Note 22 to the Consolidated Financial Statements, “Income Taxes,” for additional information.
Restricted Cash
The Duke Energy Registrants have restricted cash related primarily to collateral assets, escrow deposits and variable interest entities (VIEs). Restricted cash balances are reflected in Other within Current Assets and in Other within Investments and Other Assets on the Consolidated Balance Sheets. At December 31, 2014 and 2013, Duke Energy had restricted cash totaling $298 million and $307 million, respectively.
Inventory
Inventory is used for operations and is recorded primarily using the average cost method. Inventory related to regulated operations is valued at historical cost. Inventory related to nonregulated operations is valued at the lower of cost or market. Materials and supplies are recorded as inventory when purchased and subsequently charged to expense or capitalized to property, plant and equipment when installed. Reserves are established for excess and obsolete inventory. The components of inventory are presented in the tables below.
	December 31, 2014
(in millions)	Duke				Duke				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke				Duke
	Energy				Energy Carolinas																Energy				Energy
																					Ohio				Indiana
Materials and supplies	$	2,102			$	719			$	981			$	676			$	305			$	67			$	258
Coal held for electric generation	997				362				329				150				178				21				275
Oil, gas and other fuel held for electric generation	360				43				280				140				140				9				4
Total inventory	$	3,459			$	1,124			$	1,590			$	966			$	623			$	97			$	537
	December 31, 2013
(in millions)	Duke				Duke				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke				Duke
	Energy				Energy Carolinas																Energy				Energy
																					Ohio				Indiana
Materials and supplies	$	1,901			$	654			$	854			$	567			$	287			$	117			$	193
Coal held for electric generation	1,018				374				334				187				147				65				238
Oil, gas and other fuel held for electric generation	331				37				236				99				137				47				3
Total inventory	$	3,250			$	1,065			$	1,424			$	853			$	571			$	229			$	434
Investments in Debt and Equity Securities
The Duke Energy Registrants classify investments into two categories — trading and available-for-sale. Both categories are recorded at fair value on the Consolidated Balance Sheets. Realized and unrealized gains and losses on trading securities are included in earnings. For certain investments of regulated operations such as the Nuclear Decommissioning Trust Fund (NDTF), realized and unrealized gains and losses (including any other-than-temporary impairments) on available-for-sale securities are recorded as a regulatory asset or liability. Otherwise, unrealized gains and losses are included in Accumulated Other Comprehensive Income (AOCI), unless other-than-temporarily impaired. Other-than-temporary impairments for equity securities and the credit loss portion of debt securities of nonregulated operations are included in earnings. Investments in debt and equity securities are classified as either current or noncurrent based on management’s intent and ability to sell these securities, taking into consideration current market liquidity. See Note 15 for further information.
Goodwill and Intangible Assets
Goodwill
Duke Energy, Progress Energy and Duke Energy Ohio perform annual goodwill impairment tests as of August 31 each year at the reporting unit level, which is determined to be an operating segment or one level below. Duke Energy, Progress Energy and Duke Energy Ohio update these tests between annual tests if events or circumstances occur that would more likely than not reduce the fair value of a reporting unit below its carrying value.
In 2012, Progress Energy changed its goodwill impairment testing date from October 31 to August 31 to better align its annual goodwill impairment testing procedure with those of Duke Energy. The change had no impact on goodwill. Neither the change in the goodwill impairment testing date nor the merger resulted in any changes to the Progress Energy reporting units.
Intangible Assets
Intangible assets are included in Other in Investments and Other Assets on the Consolidated Balance Sheets. Generally, intangible assets are amortized using an amortization method that reflects the pattern in which the economic benefits of the intangible asset are consumed, or on a straight-line basis if that pattern is not readily determinable. Amortization of intangibles is reflected in Depreciation and amortization in the Consolidated Statements of Operations. Intangible assets are subject to impairment testing and if impaired, the carrying value is accordingly reduced.
Emission allowances permit the holder of the allowance to emit certain gaseous byproducts of fossil fuel combustion, including sulfur dioxide (SO2) and nitrogen oxide (NOX). Allowances are issued by the U.S. Environmental Protection Agency (EPA) at zero cost and may also be bought and sold via third-party transactions. Allowances allocated to or acquired by the Duke Energy Registrants are held primarily for consumption. Carrying amounts for emission allowances are based on the cost to acquire the allowances or, in the case of a business combination, on the fair value assigned in the allocation of the purchase price of the acquired business.
Renewable energy certificates are used to measure compliance with renewable energy standards and are held primarily for consumption. See Note 11 for further information.
Long-Lived Asset Impairments
The Duke Energy Registrants evaluate long-lived assets, excluding goodwill, for impairment when circumstances indicate the carrying value of those assets may not be recoverable. An impairment exists when a long-lived asset’s carrying value exceeds the estimated undiscounted cash flows expected to result from the use and eventual disposition of the asset. The estimated cash flows may be based on alternative expected outcomes that are probability weighted. If the carrying value of the long-lived asset is not recoverable based on these estimated future undiscounted cash flows, the carrying value of the asset is written-down to its then-current estimated fair value and an impairment charge is recognized.
The Duke Energy Registrants assess fair value of long-lived assets using various methods, including recent comparable third-party sales, internally developed discounted cash flow analysis and analysis from outside advisors. Significant changes in commodity prices, the condition of an asset or management’s interest in selling the asset are generally viewed as triggering events to re-assess cash flows. See Note 11 for further information.
Property, Plant and Equipment
Property, plant and equipment are stated at the lower of depreciated historical cost net of any disallowances or fair value, if impaired. The Duke Energy Registrants capitalize all construction-related direct labor and material costs, as well as indirect construction costs such as general engineering, taxes and financing costs. See “Allowance for Funds Used During Construction (AFUDC) and Interest Capitalized” for information on capitalized financing costs. Costs of renewals and betterments that extend the useful life of property, plant and equipment are also capitalized. The cost of repairs, replacements and major maintenance projects, which do not extend the useful life or increase the expected output of the asset, are expensed as incurred. Depreciation is generally computed over the estimated useful life of the asset using the composite straight-line method. Depreciation studies are conducted periodically to update composite rates and are approved by state utility commissions and/or the FERC when required. The composite weighted-average depreciation rates, excluding nuclear fuel, are included in the table that follows.
	Years Ended December 31,
	2014			2013			2012
Duke Energy	2.8	%		2.8	%		2.9	%
Duke Energy Carolinas	2.7	%		2.8	%		2.8	%
Progress Energy	2.5	%		2.5	%		2.6	%
Duke Energy Progress	2.5	%		2.5	%		2.7	%
Duke Energy Florida	2.7	%		2.4	%		2.5	%
Duke Energy Ohio	2.3	%		3.3	%		3.2	%
Duke Energy Indiana	3	%		2.8	%		3.3	%
In general, when the Duke Energy Registrants retire regulated property, plant and equipment, original cost plus the cost of retirement, less salvage value, is charged to accumulated depreciation. However, when it becomes probable a regulated asset will be retired substantially in advance of its original expected useful life or is abandoned, the cost of the asset and the corresponding accumulated depreciation is recognized as a separate asset. If the asset is still in operation, the net amount is classified as Generation facilities to be retired, net on the Consolidated Balance Sheets. If the asset is no longer operating, the net amount is classified in Regulatory Assets on the Consolidated Balance Sheets. The carrying value of the asset is based on historical cost if the Duke Energy Registrants are allowed to recover the remaining net book value and a return equal to at least the incremental borrowing rate. If not, an impairment is recognized to the extent the net book value of the asset exceeds the present value of future revenues discounted at the incremental borrowing rate.
When the Duke Energy Registrants sell entire regulated operating units, or retire or sell nonregulated properties, the original cost and accumulated depreciation and amortization balances are removed from Property, Plant and Equipment on the Consolidated Balance Sheets. Any gain or loss is recorded in earnings, unless otherwise required by the applicable regulatory body.
See Note 10 for further information.
Nuclear Fuel
Nuclear fuel is classified as Property, Plant and Equipment on the Consolidated Balance Sheets, except for Duke Energy Florida. Duke Energy Florida has reclassified all Crystal River Unit 3 Nuclear Station (Crystal River Unit 3) investments, including nuclear fuel, to a regulatory asset. Refer to Note 4, “Regulatory Matters,” for additional information on Crystal River Unit 3.
Nuclear fuel in the front-end fuel processing phase is considered work in progress and not amortized until placed in service. Amortization of nuclear fuel is included within Fuel used in electric generation and purchased power - regulated in the Consolidated Statements of Operations. Amortization is recorded using the units-of-production method.
Allowance for Funds Used During Construction and Interest Capitalized
For regulated operations, the debt and equity costs of financing the construction of property, plant and equipment are reflected as AFUDC and capitalized as a component of the cost of property, plant and equipment. AFUDC equity is reported on the Consolidated Statements of Operations as non-cash income in Other income and expenses, net. AFUDC debt is reported as a non-cash offset to Interest Expense. After construction is completed, the Duke Energy Registrants are permitted to recover these costs through their inclusion in rate base and the corresponding subsequent depreciation or amortization of those regulated assets.
AFUDC equity, a permanent difference for income taxes, reduces the effective tax rate when capitalized and increases the effective tax rate when depreciated or amortized. See Note 22 for additional information.
For nonregulated operations, interest is capitalized during the construction phase with an offsetting non-cash credit to Interest Expense on the Consolidated Statements of Operations.
Asset Retirement Obligations
Asset retirement obligations are recognized for legal obligations associated with the retirement of property, plant and equipment. Substantially all asset retirement obligations are related to regulated operations. When recording an asset retirement obligation, the present value of the projected liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made. The liability is accreted over time. For operating plants, the present value of the liability is added to the cost of the associated asset and depreciated over the remaining life of the asset. For retired plants, the present value of the liability is recorded as a regulatory asset and expensed over the recovery period in rates.
The present value of the initial obligation and subsequent updates are based on discounted cash flows, which include estimates regarding timing of future cash flows, selection of discount rates and cost escalation rates, among other factors. These estimates are subject to change. Depreciation expense is adjusted prospectively for any changes to the carrying amount of the associated asset. The Duke Energy Registrants receive amounts to fund the cost of the asset retirement obligation for regulated operations through a combination of regulated revenues and NDTF. As a result, the net of amounts recovered in regulated revenues, earnings on the NDTF, accretion expense and depreciation of the associated asset is deferred as a regulatory asset or liability.
Obligations for nuclear decommissioning are based on site-specific cost studies. Duke Energy Carolinas and Duke Energy Progress assume prompt dismantlement of the nuclear facilities after operations are ceased. Duke Energy Florida assumes Crystal River Unit 3 will be placed into a safe storage configuration until eventual dismantlement begins in approximately 60 years. Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida also assume that spent fuel will be stored on site until such time that it can be transferred to a U.S. Department of Energy (DOE) facility.
Obligations for closure of ash basins are based upon discounted cash flows of estimated costs based upon probability weightings of the potential closure methods as evaluated on a site by site basis. Duke Energy Registrants with ash basins in North Carolina and certain basins in South Carolina and Indiana have a legal obligation that results in recognition of an asset retirement obligation at December 31, 2014. See Notes 5 and 9 for further information.
Revenue Recognition and Unbilled Revenue
Revenues on sales of electricity and gas are recognized when service is provided or the product is delivered. Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes and meter reading schedules.
Unbilled revenues are included within Receivables and Restricted receivables of variable interest entities on the Consolidated Balance Sheets as shown in the following table. This table excludes amounts included in assets held for sale (AHFS).
	December 31,
(in millions)	2014				2013
Duke Energy	$	827			$	937
Duke Energy Carolinas	295				323
Progress Energy	217				189
Duke Energy Progress	135				120
Duke Energy Florida	82				69
Duke Energy Ohio	—				55
Duke Energy Indiana	27				5
Additionally, Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, Cinergy Receivables Company, LLC (CRC) and account for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 17 for further information. These receivables for unbilled revenues are shown in the table below.
	December 31,
(in millions)	2014			2013
Duke Energy Ohio	79			89
Duke Energy Indiana	112			144
Allowance for Doubtful Accounts
Allowances for doubtful accounts are presented in the following table.
	December 31,
(in millions)	2014				2013			2012
Allowance for Doubtful Accounts
Duke Energy	$	17			30			34
Duke Energy Carolinas	3				3			3
Progress Energy	8				14			16
Duke Energy Progress	7				10			9
Duke Energy Florida	2				4			7
Duke Energy Ohio	2				2			2
Duke Energy Indiana	1				1			1
Allowance for Doubtful Accounts - VIEs
Duke Energy	$	51			43			44
Duke Energy Carolinas	6				6			6
Progress Energy	8				—			—
Duke Energy Progress	5				—			—
Duke Energy Florida	3				—			—
Derivatives and Hedging
Derivative and non-derivative instruments may be used in connection with commodity price, interest rate and foreign currency risk management activities, including swaps, futures, forwards and options. All derivative instruments except those that qualify for the normal purchase/normal sale (NPNS) exception are recorded on the Consolidated Balance Sheets at their fair value. Qualifying derivative instruments may be designated as either cash flow hedges or fair value hedges. Other derivative instruments (undesignated contracts) either have not been designated or do not qualify as hedges. The effective portion of the change in the fair value of cash flow hedges is recorded in AOCI. The effective portion of the change in the fair value of a fair value hedge is offset in net income by changes in the hedged item. For activity subject to regulatory accounting, gains and losses on derivative contracts are reflected as regulatory assets or liabilities and not as other comprehensive income or current period income. As a result, changes in fair value of these derivatives have no immediate earnings impact.
Formal documentation, including transaction type and risk management strategy, is maintained for all contracts accounted for as a hedge. At inception and at least every three months thereafter, the hedge contract is assessed to see if it is highly effective in offsetting changes in cash flows or fair values of hedged items.
See Note 14 for further information.
Captive Insurance Reserves
Duke Energy has captive insurance subsidiaries that provide coverage, on an indemnity basis, to the Subsidiary Registrants as well as certain third parties, on a limited basis, for various business risks and losses, such as property, workers’ compensation and general liability. Liabilities include provisions for estimated losses incurred but not yet reported (IBNR), as well as estimated provisions for known claims. IBNR reserve estimates are primarily based upon historical loss experience, industry data and other actuarial assumptions. Reserve estimates are adjusted in future periods as actual losses differ from experience.
Duke Energy, through its captive insurance entities, also has reinsurance coverage with third parties for certain losses above a per occurrence and/or aggregate retention. Receivables for reinsurance coverage are recognized when realization is deemed probable.
Unamortized Debt Premium, Discount and Expense
Premiums, discounts and expenses incurred with the issuance of outstanding long-term debt are amortized over the term of the debt issue. Call premiums and unamortized expenses associated with refinancing higher-cost debt obligations in the regulated operations are amortized. Amortization expense is recorded as Interest Expense in the Consolidated Statements of Operations and is reflected as Depreciation, amortization and accretion within Net cash provided by operating activities on the Consolidated Statements of Cash Flows.
Loss Contingencies and Environmental Liabilities
Contingent losses are recorded when it is probable a loss has occurred and can be reasonably estimated. When a range of the probable loss exists and no amount within the range is a better estimate than any other amount, the minimum amount in the range is recorded. Unless otherwise required by GAAP, legal fees are expensed as incurred.
Environmental liabilities are recorded on an undiscounted basis when environmental remediation or other liabilities becomes probable and can be reasonably estimated. Environmental expenditures related to past operations that do not generate current or future revenues are expensed. Environmental expenditures related to operations that generate current or future revenues are expensed or capitalized, as appropriate. Certain environmental expenditures receive regulatory accounting treatment and are recorded as regulatory assets.
See Notes 4 and 5 for further information.
Pension and Other Post-Retirement Benefit Plans
Duke Energy maintains qualified, non-qualified and other post-retirement benefit plans. Eligible employees of the Subsidiary Registrants participate in the respective qualified, non-qualified and other post-retirement benefit plans and the Subsidiary Registrants are allocated their proportionate share of benefit costs. See Note 21 for further information, including significant accounting policies associated with these plans.
Severance and Special Termination Benefits
Duke Energy has an ongoing severance plan under which, in general, the longer a terminated employee worked prior to termination the greater the amount of severance benefits. A liability for involuntary severance is recorded once an involuntary severance plan is committed to by management, or sooner, if involuntary severances are probable and can be reasonably estimated. For involuntary severance benefits incremental to its ongoing severance plan benefits, the fair value of the obligation is expensed at the communication date if there are no future service requirements, or over the required future service period. From time to time, Duke Energy offers special termination benefits under voluntary severance programs. Special termination benefits are recorded immediately upon employee acceptance absent a significant retention period. Otherwise, the cost is recorded over the remaining service period. Employee acceptance of voluntary severance benefits is determined by management based on the facts and circumstances of the benefits being offered. See Note 19 for further information.
Guarantees
Liabilities are recognized at the time of issuance or material modification of a guarantee for the estimated fair value of the obligation it assumes. Fair value is estimated using a probability-weighted approach. The obligation is reduced over the term of the guarantee or related contract in a systematic and rational method as risk is reduced. Any additional contingent loss for guarantee contracts subsequent to the initial recognition of a liability is accounted for and recognized at the time a loss is probable and can be reasonably estimated. See Note 7 for further information.
Stock-Based Compensation
Stock-based compensation represents costs related to stock-based awards granted to employees and Duke Energy Board of Directors (Board of Directors) members. Duke Energy recognizes stock-based compensation based upon the estimated fair value of awards, net of estimated forfeitures at the date of issuance. The recognition period for these costs begin at either the applicable service inception date or grant date and continues throughout the requisite service period, or for certain share-based awards until the employee becomes retirement eligible, if earlier. Compensation cost is recognized as expense or capitalized as a component of property, plant and equipment. See Note 20 for further information.
Income Taxes
Duke Energy and its subsidiaries file a consolidated federal income tax return and other state and foreign jurisdictional returns. The Subsidiary Registrants entered into a tax-sharing agreement with Duke Energy. Income taxes recorded represent amounts the Subsidiary Registrants would incur as separate C-Corporations. Deferred income taxes have been provided for temporary differences between GAAP and tax bases of assets and liabilities because the differences create taxable or tax-deductible amounts for future periods. Deferred taxes are not provided on translation gains and losses when earnings of a foreign operation are expected to be indefinitely reinvested. Investment tax credits (ITC) associated with regulated operations are deferred and amortized as a reduction of income tax expense over the estimated useful lives of the related properties.
Positions taken or expected to be taken on tax returns, including the decision to exclude certain income or transactions from a return, are recognized in the financial statements when it is more likely than not the tax position can be sustained based solely on the technical merits of the position. The largest amount of tax benefit that is greater than 50 percent likely of being effectively settled is recorded. Management considers a tax position effectively settled when: (i) the taxing authority has completed its examination procedures, including all appeals and administrative reviews; (ii) the Duke Energy Registrants do not intend to appeal or litigate the tax position included in the completed examination; and (iii) it is remote the taxing authority would examine or re-examine the tax position. The amount of a tax return position that is not recognized in the financial statements is disclosed as an unrecognized tax benefit. If these unrecognized tax benefits are later recognized, then there will be a decrease in income taxes payable, an income tax refund or a swap between deferred and current taxes payable. If the portion of tax benefits that has been recognized changes and those tax benefits are subsequently unrecognized, then the previously recognized tax benefits may impact the financial statements through increasing income taxes payable, reducing income tax refunds receivable changing deferred taxes. Changes in assumptions on tax benefits may also impact interest expense or interest income and may result in the recognition of tax penalties.
Tax-related interest and penalties are recorded in Interest Expense and Other Income and Expenses, net, in the Consolidated Statements of Operations.
See Note 22 for further information.
Accounting for Renewable Energy Tax Credits and Cash Grants
When Duke Energy receives ITC or cash grants on wind or solar facilities, it reduces the basis of the property recorded on the Consolidated Balance Sheets by the amount of the ITC or cash grant and, therefore, the ITC or grant benefit is recognized through reduced depreciation expense. Additionally, certain tax credits and government grants received provide for initial tax depreciable base in excess of the book carrying value equal to one half of the ITC or government grant. Deferred tax benefits are recorded as a reduction to income tax expense in the period that the basis difference is created.
Excise Taxes
Certain excise taxes levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis. Otherwise, the taxes are accounted for net. Excise taxes accounted for on a gross basis as both operating revenues and property and other taxes in the Consolidated Statements of Operations were as follows.
	Years Ended December 31,
(in millions)	2014				2013				2012
Duke Energy	$	498			$	602			$	466
Duke Energy Carolinas	94				164				161
Progress Energy	263				304				317
Duke Energy Progress	56				115				113
Duke Energy Florida	207				189				205
Duke Energy Ohio	103				105				102
Duke Energy Indiana	38				29				33
During the third quarter of 2014, the North Carolina gross receipts tax was terminated due to the North Carolina Tax Simplification and Rate Reduction Act. The North Carolina gross receipts tax is no longer imposed effective July 1, 2014.
On July 23, 2013, North Carolina House Bill 998 (HB 998) was signed into law. HB 998 repealed the utility franchise tax effective July 1, 2014. The utility franchise tax was 3.22 percent gross receipts tax on sales of electricity. The result of this change in law will be an annual reduction in excise taxes of approximately $160 million for Duke Energy Carolinas and approximately $110 million for Duke Energy Progress. HB 998 also increases sales tax on electricity from 3 percent to 7 percent effective July 1, 2014. HB 998 requires the NCUC to adjust retail electric rates for the elimination of the utility franchise tax, changes due to the increase in sales tax on electricity, and the resulting change in liability of utility companies under the general franchise tax.
Foreign Currency Translation
The local currencies of most of Duke Energy’s foreign operations have been determined to be their functional currencies. However, certain foreign operations’ functional currency has been determined to be the U.S. dollar, based on an assessment of the economic circumstances of the foreign operation. Assets and liabilities of foreign operations whose functional currency is not the U.S. dollar are translated into U.S. dollars at the exchange rates in effect at period end. Translation adjustments resulting from changes in exchange rates are included in AOCI. Revenue and expense accounts are translated at average exchange rates during the year. Remeasurement gains and losses arising from balances and transactions denominated in currencies other than the local currency are included in the results of operations when they occur.
Dividend Restrictions and Unappropriated Retained Earnings
Duke Energy does not have any legal, regulatory or other restrictions on paying common stock dividends to shareholders. However, as further described in Note 4, due to conditions established by regulators in conjunction with merger transaction approvals, Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana have restrictions on paying dividends or otherwise advancing funds to Duke Energy. At December 31, 2014 and 2013, an insignificant amount of Duke Energy’s consolidated Retained earnings balance represents undistributed earnings of equity method investments.
New Accounting Standards
The new accounting standards that were adopted for 2014, 2013 and 2012 had no significant impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. Disclosures have been enhanced to provide a discussion and tables on derivative contracts subject to enforceable master netting agreements and a table of quantitative disclosures about unobservable inputs. See Notes 14 and 16 for further information.
The following new Accounting Standards Updates (ASUs) have been issued, but have not yet been adopted by the Duke Energy Registrants, as of December 31, 2014.
ASC 205 — Reporting Discontinued Operations. In April 2014, the Financial Accounting Standards Board (FASB) issued revised accounting guidance for reporting discontinued operations. A discontinued operation would be either (i) a component of an entity or a group of components of an entity that represents a separate major line of business or major geographical area of operations that either has been disposed of or is part of a single coordinated plan to be classified as held for sale or (ii) a business that, on acquisition, meets the criteria to be classified as held for sale.
For the Duke Energy Registrants, this guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2015. This guidance will also result in increased disclosures for discontinued operations or disposals of individually significant components that are not classified as discontinued operations. In general, this guidance is likely to result in fewer disposals of assets qualifying as discontinued operations.
ASC 606 — Revenue from Contracts with Customers. In May 2014, the FASB issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendments in this update also require disclosure of sufficient information to allow users to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers.
For the Duke Energy Registrants, this guidance is effective for interim and annual periods beginning January 1, 2017. Duke Energy is currently evaluating the requirements. The ultimate impact of the new standard has not yet been determined.

Acquisitions_Dispositions_and_

Acquisitions, Dispositions and Sales of Other Assets	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Acquisitions, Dispositions and Sales of Other Assets	ACQUISITIONS, DISPOSITIONS AND SALES OF OTHER ASSETS
	ACQUISITIONS
	The Duke Energy Registrants consolidate assets and liabilities from acquisitions as of the purchase date, and include earnings from acquisitions in consolidated earnings after the purchase date.
	Purchase of NCEMPA's Generation
	On September 5, 2014, Duke Energy Progress executed an agreement to purchase North Carolina Eastern Municipal Power Agency’s (NCEMPA) ownership interests in certain generating assets jointly owned with and operated by Duke Energy Progress. The agreement provides for the acquisition of a total of approximately 700 megawatts (MW) at Brunswick Nuclear Station (Brunswick), Shearon Harris Nuclear Station (Harris), Mayo Steam Station and Roxboro Steam Station. The purchase price for the ownership interest and fuel and spare parts inventory is approximately $1.2 billion. Under the agreement, Duke Energy Progress and NCEMPA will enter into a 30-year wholesale power supply agreement to continue meeting the needs of NCEMPA’s customers. Closing of the transaction is subject to certain conditions, including state and federal regulatory approvals and legislative action required prior to completing the transaction. On December 9, 2014, the FERC approved Duke Energy Progress' request to purchase NCEMPA's interests in the generation assets, approved Duke Energy Progress' 30-year wholesale power supply agreement with NCEMPA, and approved Duke Energy Progress' inclusion of the acquisition adjustment resulting from the asset purchase in wholesale power formula rates. The transaction is expected to close by the end of 2015 or early 2016.
	Merger with Progress Energy
	On July 2, 2012, Duke Energy completed its merger with Progress Energy, a North Carolina corporation engaged in the regulated utility business of generation, transmission and distribution and sale of electricity in portions of North Carolina, South Carolina and Florida. As a result of the merger, Progress Energy became a wholly owned subsidiary of Duke Energy.
	The merger between Duke Energy and Progress Energy provides increased scale and diversity with potentially enhanced access to capital over the long term and a greater ability to undertake the significant construction programs necessary to respond to increasing environmental regulation, plant retirements and customer demand growth. Duke Energy’s business risk profile is expected to improve over time due to the increased proportion of the business that is regulated. Additionally, cost savings, efficiencies and other benefits are expected from the combined operations.
	Purchase Price
	Total consideration transferred was based on the closing price of Duke Energy common shares on July 2, 2012, and was calculated as shown in the following table.
	(dollars in millions, except per share amounts; shares in thousands)
	Progress Energy common shares outstanding at July 2, 2012	296,116
	Exchange ratio	0.87083
	Duke Energy common shares issued for Progress Energy common shares outstanding	257,867
	Closing price of Duke Energy common shares on July 2, 2012	$	69.84
	Purchase price for common stock	$	18,009
	Fair value of outstanding earned stock compensation awards	62
	Total purchase price	$	18,071
	Progress Energy’s stock-based compensation awards, including performance shares and restricted stock, were replaced with Duke Energy awards upon consummation of the merger. In accordance with accounting guidance for business combinations, a portion of the fair value of these awards is included in the purchase price as it represents consideration transferred in the merger.
	Purchase Price Allocation
	Fair value of assets acquired and liabilities assumed was determined based on significant estimates and assumptions, including Level 3 inputs, which are judgmental in nature. Estimates and assumptions include the projected timing and amount of future cash flows, discount rates reflecting risk inherent in future cash flows, and future market prices.
	Additionally, the February 5, 2013 announcement of the decision to retire Crystal River Unit 3 reflected additional information related to facts and circumstances existing as of the acquisition date. See Note 4 for additional information related to Crystal River Unit 3. As such, Duke Energy presents assets acquired and liabilities assumed as if the retirement of Crystal River Unit 3 occurred on the acquisition date.
	The majority of Progress Energy’s operations are subject to the rate-setting authority of the FERC, NCUC, PSCSC, and FPSC and are accounted for pursuant to U.S. GAAP, including the accounting guidance for regulated operations. Rate-setting and cost recovery provisions currently in place for Progress Energy’s regulated operations provide revenues derived from costs, including a return on investment of assets and liabilities included in rate base. Except for long-term debt, asset retirement obligations, capital leases, pension and other post-retirement benefit obligations (OPEB), and the wholesale portion of Crystal River Unit 3, fair values of tangible and intangible assets and liabilities subject to these rate-setting provisions approximate their carrying values. Accordingly, assets acquired and liabilities assumed and pro forma financial information do not reflect any net adjustments related to these amounts. The difference between fair value and pre-merger carrying amounts for long-term debt, asset retirement obligations, capital leases and pension and OPEB plans for regulated operations were recorded as Regulatory assets.
	The excess of purchase price over estimated fair values of assets acquired and liabilities assumed was recognized as goodwill at the acquisition date. The goodwill reflects the value paid primarily for long-term potential for enhanced access to capital as a result of increased scale and diversity, opportunities for synergies, and an improved risk profile. Goodwill resulting from the merger was allocated entirely to the Regulated Utilities segment. None of the goodwill recognized is deductible for income tax purposes, and as such, no deferred taxes have been recorded related to goodwill.
	The completed purchase price allocation is presented in the following table.
	(in millions)
	Current assets	$	3,204
	Property, plant and equipment	23,141
	Goodwill	12,469
	Other long-term assets	9,990
	Total assets	48,804
	Current liabilities, including current maturities of long-term debt	3,593
	Long-term liabilities, preferred stock and noncontrolling interests	10,394
	Long-term debt	16,746
	Total liabilities and preferred stock	30,733
	Total purchase price	$	18,071
	The purchase price allocation in the table above reflects refinements made to preliminary fair values of assets acquired and liabilities assumed as of December 31, 2012. These refinements include adjustments associated with the retirement of Crystal River Unit 3. The changes resulted in an increase to Goodwill of $2 million, an increase to the fair value of Current liabilities, including current maturities of long-term debt of $12 million, a decrease to Property, plant and equipment of $138 million, a decrease to Other long-term assets of $4 million and a decrease to Long-term liabilities, preferred stock and noncontrolling interests of $152 million. These refinements had no impact on the amortization of purchase accounting adjustments recorded to earnings during the year ended December 31, 2013, or for the six months ended December 31, 2012.
	Pro Forma Financial Information
	The following unaudited pro forma financial information reflects the consolidated results of operations of Duke Energy and the amortization of purchase price adjustments assuming the merger had taken place on January 1, 2012. The unaudited pro forma financial information has been presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved or future consolidated results of operations of Duke Energy.
	Non-recurring merger consummation, integration and other costs incurred by Duke Energy and Progress Energy during the period have been excluded from pro forma earnings presented below. After-tax non-recurring merger consummation, integration and other costs incurred by both Duke Energy and Progress Energy were $413 million for the year ended 2012. The pro forma financial information also excludes potential future cost savings or non-recurring charges related to the merger.
		Year Ended December 31,
	(in millions, except per share amounts)	2012
	Revenues	$	23,976
	Net Income Attributable to Duke Energy Corporation	2,417
	Basic and Diluted Earnings Per Share	3.43
	Accounting Charges Related to the Merger Consummation
	The following pretax consummation charges were recognized upon closing of the merger and are included in the Duke Energy Registrants’ Consolidated Statements of Operations and Comprehensive Income for the year ended December 31, 2012.
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	FERC Mitigation	$	117		$	46		$	71	$	71	$	—	$	—	$	—
	Severance costs	196			63			82		55		27		21		18
	Community support, charitable	169			79			74		63		11		7		6
	contributions and other
	Total	$	482		$	188		$	227	$	189	$	38	$	28	$	24
	FERC Mitigation charges reflect the portion of transmission project costs probable of disallowance, impairment of the carrying value of the generation assets serving Interim FERC Mitigation, and mark-to-market losses recognized on power sale agreements upon closing of the merger. Charges related to transmission projects and impairment of the carrying value of generation assets were recorded within Impairment charges in the Consolidated Statements of Operations. Mark-to-market losses on interim power sale agreements was recorded in Regulated electric operating revenues in the Consolidated Statements of Operations. Subsequent changes in fair value of interim power sale agreements over the life of the contracts and realized gains or losses on interim contract sales are also recorded within Regulated electric operating revenues. The ability to successfully defend future recovery of a portion of transmission projects in rates and any future changes to estimated transmission project costs could impact the amount not expected to be recovered.
	In conjunction with the merger, in November 2011, Duke Energy and Progress Energy each offered a voluntary severance plan (VSP) to certain eligible employees. VSP and other severance costs incurred were recorded primarily within Operation, maintenance and other in the Consolidated Statements of Operations. See Note 19 for further information related to employee severance expenses.
	Community support, charitable contributions and other reflect (i) the unconditional obligation to provide funding at a level comparable to historic practices over the next four years, and (ii) financial and legal advisory costs incurred upon the closing of the merger, retention and relocation costs paid to certain employees. These charges were recorded within Operation, maintenance and other in the Consolidated Statements of Operations.
	Impact of Merger
	The impact of Progress Energy on Duke Energy’s revenues and net income attributable to Duke Energy in the Consolidated Statements of Operations for the year ended December 31, 2012 was an increase of $4,943 million and $368 million, respectively.
	Chilean Operations
	In December 2012, Duke Energy acquired Iberoamericana de Energía Ibener, S.A. (Ibener) of Santiago, Chile, for cash consideration of $415 million. This acquisition included the 140 MW Duqueco hydroelectric generation complex consisting of two run-of-the-river plants located in southern Chile. Purchase price allocation consisted primarily of $383 million of property, plant and equipment, $30 million of intangible assets, $57 million of deferred income tax liabilities, $54 million of goodwill and $8 million of working capital.
	DISPOSITIONS
	Midwest Generation Exit
	On August 21, 2014, Duke Energy Commercial Enterprises, Inc., an indirect wholly owned subsidiary of Duke Energy Corporation, and Duke Energy SAM, LLC, a wholly owned subsidiary of Duke Energy Ohio, entered into a PSA with a subsidiary of Dynegy whereby Dynegy will acquire Duke Energy’s Disposal Group for approximately $2.8 billion in cash subject to adjustments at closing for changes in working capital and capital expenditures. The completion of the transaction is conditioned on approval by FERC. On January 16, 2015, FERC issued a letter requesting additional information in connection with the transaction application. The request was for further economic analysis relating to the combined market power impacts of the proposed transaction and Dynegy's simultaneous acquisition of other assets in the PJM Interconnection, LLC (PJM) market, and information relating to rate protections for Dynegy's customers. On February 6, 2015, Duke Energy and Dynegy made two filings with FERC. The first filing provided additional information requested by FERC. The second filing provided information related to Dynegy's settlement agreement with the Independent Market Monitor for PJM, which no longer opposes the proposed transaction. The transaction is expected to close by the end of the second quarter of 2015.
	The Disposal Group is included in the Commercial Power segment. The following table presents information related to the Duke Energy Ohio generation plants included in the Disposal Group.
Facility	Plant Type		Primary Fuel	Location		Total MW Capacity(c)		Owned MW Capacity(c)	Ownership Interest
Stuart(a)(b)	Fossil Steam		Coal	OH		2,308		900	39	%
Zimmer(a)	Fossil Steam		Coal	OH		1,300		605	46.5	%
Hanging Rock	Combined Cycle		Gas	OH		1,226		1,226	100	%
Miami Fort (Units 7 and 8)(a)	Fossil Steam		Coal	OH		1,020		652	64	%
Conesville(a)(b)	Fossil Steam		Coal	OH		780		312	40	%
Washington	Combined Cycle		Gas	OH		617		617	100	%
Fayette	Combined Cycle		Gas	PA		614		614	100	%
Killen(a)(b)	Fossil Steam		Coal	OH		600		198	33	%
Lee	Combustion Turbine		Gas	IL		568		568	100	%
Dick's Creek	Combustion Turbine		Gas	OH		136		136	100	%
Miami Fort	Combustion Turbine		Oil	OH		56		56	100	%
Total Midwest Generation						9,225		5,884
(a)	Jointly owned with American Electric Power Generation Resources and/or The Dayton Power & Light Company.
(b)	Station is not operated by Duke Energy Ohio.
(c)	Total MW capacity is based on summer capacity.
The Disposal Group also includes a retail sales business owned by Duke Energy. In the second quarter of 2014, Duke Energy Ohio removed Ohio Valley Electric Corporation's (OVEC) purchase power agreement from the Disposal Group as it no longer intended to sell it with the Disposal Group. Duke Energy Ohio has requested cost-based recovery of its contractual entitlement in OVEC in its 2014 Electric Security Plan (ESP) application filed on May 29, 2014. See Note 4 for information related to the 2014 ESP.
The assets and associated liabilities of the Disposal Group are classified as held for sale in Duke Energy's and Duke Energy Ohio's Consolidated Balance Sheets at December 31, 2014.
The results of operations of the Disposal Group are classified as discontinued operations for current and prior periods in the accompanying Consolidated Statements of Operations and Comprehensive Income. Certain immaterial costs that that may be eliminated as a result of the sale have remained in continuing operations. The following table presents the results of discontinued operations.
Duke Energy
	Years Ended December 31,
(in millions)	2014			2013			2012
Operating Revenues	$	1,748		$	1,885		$	1,771
Estimated loss on disposition	(929		)	—			—
(Loss) Income before income taxes	$	(818	)	$	141		$	227
Income tax (benefit) expense	(294		)	56			82
(Loss) Income from discontinued operations of the Disposal Group	(524		)	85			145
Other, net of tax(a)	(52		)	1			26
(Loss) Income from Discontinued Operations, net of tax	$	(576	)	$	86		$	171
(a)	Other discontinued operations relate to prior sales of businesses and includes indemnifications provided for certain legal, tax and environmental matters, and foreign currency translation adjustments.
Duke Energy Ohio
	Years Ended December 31,
(in millions)	2014			2013			2012
Operating Revenues	$	1,299		$	1,503		$	1,435
Estimated loss on disposition	(959		)	—			—
(Loss) Income before income taxes	$	(863	)	$	67		$	195
Income tax (benefit) expense	(300		)	32			65
(Loss) Income from Discontinued Operations, net of tax	$	(563	)	$	35		$	130
The Duke Energy and Duke Energy Ohio held for sale assets include net pretax impairments of approximately $929 million and $959 million, respectively, for the year ended December 31, 2014. The impairment was recorded to write-down the carrying amount of the assets to the estimated fair value of the business, based on the expected selling price to Dynegy less cost to sell. These losses were included in (Loss) Income from Discontinued Operations, net of tax in the Consolidated Statements of Operations and Comprehensive Income. The impairment will be updated, if necessary, based on the final sales price, after any adjustments at closing for working capital and capital expenditures.
Commercial Power has a revolving credit agreement (RCA) to support the operations of the nonregulated Midwest generation business. Interest expense associated with the RCA has been allocated to discontinued operations. No other interest expense related to corporate level debt has been allocated to discontinued operations.
The following table presents the Disposal Group's carrying values in the Consolidated Balance Sheets' major classes of Assets held for sale.
	December 31, 2014
(in millions)	Duke Energy			Duke Energy Ohio
Current assets	$	364		$	316
Investments and other assets	52			46
Property, plant and equipment	2,590			2,559
Total assets held for sale	$	3,006		$	2,921
Current liabilities	$	262		$	246
Deferred credits and other liabilities	35			34
Total liabilities associated with assets held for sale	$	297		$	280
Duke Energy Ohio may continue to have transactions with the Disposal Group after the divestiture is complete depending on when the transaction closes. Duke Energy Ohio has a power purchase agreement with the Disposal Group, which extends through May 2015, for a portion of its standard service offer (SSO) supply requirement. In addition, for a period of up to 12 months, Duke Energy may provide transition services to Dynegy. Duke Energy will be reimbursed for transition services provided. The continuing cash flows are not expected to be material and are not considered direct cash flows. These arrangements do not allow Duke Energy or Duke Energy Ohio to significantly influence the operations of the Disposal Group once the sale is complete.
See Notes 4 and 5 for a discussion of contingencies related to the Disposal Group that will be retained by Duke Energy Ohio subsequent to the sale.
Vermillion Generating Station
On January 12, 2012, after receiving approvals from the FERC and IURC on August 12, 2011 and December 28, 2011, respectively, Duke Energy Vermillion II, LLC (Duke Energy Vermillion), an indirect wholly owned subsidiary of Duke Energy Ohio, completed the sale of its ownership interest in Vermillion Generating Station (Vermillion) to Duke Energy Indiana and Wabash Valley Power Association, Inc. (WVPA). Upon closing of the sale, Duke Energy Indiana held a 62.5 percent interest in Vermillion. Duke Energy Ohio received net proceeds of $82 million, of which $68 million was paid by Duke Energy Indiana. Following the transaction, Duke Energy Indiana retired Gallagher Units 1 and 3 effective February 1, 2012.
As Duke Energy Indiana is an affiliate of Duke Energy Vermillion, the transaction was accounted for as a transfer between entities under common control with no gain or loss recorded and did not have a significant impact to Duke Energy Ohio’s or Duke Energy Indiana’s results of operations. Proceeds received from Duke Energy Indiana are included in Net proceeds from the sales of other assets on Duke Energy Ohio’s Consolidated Statements of Cash Flows. Cash paid to Duke Energy Ohio is included in Capital expenditures on Duke Energy Indiana’s Consolidated Statements of Cash Flows. Duke Energy Ohio and Duke Energy Indiana recognized non-cash equity transfers of $28 million and $26 million, respectively, in their Consolidated Statements of Common Stockholder’s Equity on the transaction representing the difference between cash exchanged and the net book value of Vermillion. These amounts are not reflected in Duke Energy’s Consolidated Statements of Cash Flows or Consolidated Statements of Equity as the transaction is eliminated in consolidation.
Proceeds from WVPA are included in Net proceeds from the sales of other assets on Duke Energy Ohio’s Consolidated Statements of Cash Flows and Net proceeds from the sales of equity investments and other assets, and sales of and collections on notes receivable on Duke Energy’s Consolidated Statements of Cash Flows. The sale of the proportionate share of Vermillion to WVPA did not result in a significant gain or loss upon close of the transaction.
Sales Of Other Assets
During 2012, Duke Energy received proceeds of $187 million from the sale of non-core business assets within the Commercial Power segment for which no material gain or loss was recognized.

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Business Segments	BUSINESS SEGMENTS
	Duke Energy evaluates segment performance based on segment income. Segment income is defined as income from continuing operations net of income attributable to noncontrolling interests. Segment income, as discussed below, includes intercompany revenues and expenses that are eliminated in the Consolidated Financial Statements. Certain governance costs are allocated to each segment. In addition, direct interest expense and income taxes are included in segment income.
	Operating segments are determined based on information used by the chief operating decision maker in deciding how to allocate resources and evaluate the performance.
	Products and services are sold between affiliate companies and reportable segments of Duke Energy at cost. Segment assets as presented in the tables that follow exclude all intercompany assets.
	Duke Energy
	Duke Energy has the following reportable operating segments: Regulated Utilities, International Energy and Commercial Power.
	Regulated Utilities conducts operations primarily through Duke Energy Carolinas, Duke Energy Progress, Duke Energy Florida, Duke Energy Indiana, and the regulated transmission and distribution operations of Duke Energy Ohio. These electric and natural gas operations are subject to the rules and regulations of the FERC, NCUC, PSCSC, FPSC, PUCO, IURC and KPSC. Substantially all of Regulated Utilities’ operations are regulated and, accordingly, these operations qualify for regulatory accounting treatment.
	International Energy principally operates and manages power generation facilities and engages in sales and marketing of electric power, natural gas and natural gas liquids outside the U.S. Its activities principally target power generation in Latin America. Additionally, International Energy owns a 25 percent interest in National Methanol Company (NMC), a large regional producer of methyl tertiary butyl ether (MTBE) located in Saudi Arabia. The investment in NMC is accounted for under the equity method of accounting.
	Commercial Power builds, develops and operates renewable generation and energy transmission projects throughout the continental U.S. As discussed in Note 2, Duke Energy entered into an agreement to sell Commercial Power's nonregulated Midwest generation business to Dynegy in a transaction that is expected to close during the second quarter of 2015. As a result of this divestiture, the results of operations of the nonregulated Midwest generation business have been reclassified to Discontinued Operations on the Consolidated Statements of Operations. Certain costs such as interest and general and administrative expenses previously allocated to the Disposal Group were not reclassified to discontinued operations.
	The remainder of Duke Energy’s operations is presented as Other. While it is not an operating segment, Other primarily includes unallocated corporate interest expense, certain unallocated corporate costs, Bison Insurance Company Limited (Bison), Duke Energy’s wholly owned, captive insurance subsidiary, and contributions to the Duke Energy Foundation. On December 31, 2013, Duke Energy sold its interest in DukeNet Communications Holdings, LLC (DukeNet) to Time Warner Cable, Inc.
		Year Ended December 31, 2014
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
	Unaffiliated Revenues	$	22,228		$	1,417		$	255		$	23,900		$	25		$	—		$	23,925
	Intersegment Revenues	43			—			—			43			80			(123		)	—
	Total Revenues	$	22,271		$	1,417		$	255		$	23,943		$	105		$	(123	)	$	23,925
	Interest Expense	$	1,093		$	93		$	58		$	1,244		$	400		$	(22	)	$	1,622
	Depreciation and amortization	2,759			97			92			2,948			118			—			3,066
	Equity in earnings of unconsolidated affiliates	(3		)	120			10			127			3			—			130
	Income tax expense (benefit)(a)	1,628			449			(171		)	1,906			(237		)	—			1,669
	Segment income(b)(c)(d)	2,795			55			(55		)	2,795			(334		)	(10		)	2,451
	Add back noncontrolling interest component																			14
	Loss from discontinued operations, net of tax																			(576		)
	Net income																			$	1,889
	Capital investments expenditures and acquisitions	$	4,744		$	67		$	555		$	5,366		$	162		$	—		$	5,528
	Segment Assets	106,657			5,132			6,278			118,067			2,453			189			120,709
	(a)	International Energy includes a tax adjustment of $373 million related to deferred tax impact resulting from the decision to repatriate all cumulative historical undistributed foreign earnings. See Note 22 for additional information.
	(b)	Commercial Power recorded a pretax impairment charge of $94 million related to OVEC. See Note 11 for additional information.
	(c)	Other includes costs to achieve the Progress Energy merger. See Notes 2 and 25 for additional information about the merger and related costs.
	(d)	Regulated Utilities includes an increase in the litigation reserve related to the criminal investigation of the Dan River coal ash spill. See Note 5 for additional information.
		Year Ended December 31, 2013
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
	Unaffiliated Revenues(a)(b)(c)	$	20,871		$	1,546		$	254		$	22,671		$	85		$	—		$	22,756
	Intersegment Revenues	39			—			6			45			90			(135		)	—
	Total Revenues	$	20,910		$	1,546		$	260		$	22,716		$	175		$	(135	)	$	22,756
	Interest Expense	$	986		$	86		$	61		$	1,133		$	416		$	(6	)	$	1,543
	Depreciation and amortization	2,323			100			110			2,533			135			—			2,668
	Equity in earnings of unconsolidated affiliates	(1		)	110			7			116			6			—			122
	Income tax expense (benefit)	1,522			166			(148		)	1,540			(335		)	—			1,205
	Segment income (a)(b)(c)(d)(e)(f)(g)	2,504			408			(88		)	2,824			(238		)	(12		)	2,574
	Add back noncontrolling interest component																			16
	Income from discontinued operations, net of tax																			86
	Net income																			$	2,676
	Capital investments expenditures and acquisitions	$	5,049		$	67		$	268		$	5,384		$	223		$	—		$	5,607
	Segment Assets	99,884			4,998			6,955			111,837			2,754			188			114,779
	(a)	In May 2013, the PUCO approved a Duke Energy Ohio settlement agreement that provides for a net annual increase in electric distribution revenues beginning in May 2013. This rate increase impacts Regulated Utilities. See Note 4 for additional information.
	(b)	In June 2013, NCUC approved a Duke Energy Progress settlement agreement that included an increase in rates in the first year beginning in June 2013. This rate increase impacts Regulated Utilities. See Note 4 for additional information.
	(c)	In September 2013, Duke Energy Carolinas implemented revised customer rates approved by the NCUC and the PSCSC. These rate increases impact Regulated Utilities. See Note 4 for additional information.
	(d)	Regulated Utilities recorded an impairment charge related to Duke Energy Florida's Crystal River Unit 3. See Note 4 for additional information.
	(e)	Regulated Utilities recorded an impairment charge related to the letter Duke Energy Progress filed with the NRC requesting the NRC to suspend its review activities associated with the combined construction and operating license (COL) at the Harris site. Regulated Utilities also recorded an impairment charge related to the write-off of the wholesale portion of the Levy investments at Duke Energy Florida in accordance with the 2013 Settlement. See Note 4 for additional information.
	(f)	Other includes costs to achieve the Progress Energy merger. See Notes 2 and 25 for additional information about the merger and related costs.
	(g)	Other includes gain from the sale of Duke Energy's ownership interest in DukeNet. See Note 12 for additional information on the sale of DukeNet.
		Year Ended December 31, 2012
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Reportable Segments			Other			Eliminations			Total
	Unaffiliated Revenues	$	16,042		$	1,549		$	299		$	17,890		$	22		$	—		$	17,912
	Intersegment Revenues	38			—			8			46			62			(108		)	—
	Total Revenues	$	16,080		$	1,549		$	307		$	17,936		$	84		$	(108	)	$	17,912
	Interest Expense	$	806		$	77		$	63		$	946		$	298		$	—		$	1,244
	Depreciation and amortization	1,827			99			85			2,011			134			—			2,145
	Equity in earnings of unconsolidated affiliates	(5		)	134			14			143			5			—			148
	Income tax expense (benefit)	942			149			(82		)	1,009			(386		)	—			623
	Segment income (a)(b)	1,744			439			(59		)	2,124			(523		)	(8		)	1,593
	Add back noncontrolling interest component																			18
	Income from discontinued operations, net of tax																			171
	Net income																			$	1,782
Capital investments expenditures and acquisitions	$	4,220		$	551		$	1,038		$	5,809		$	149		$	—		$	5,958
Segment Assets	98,162			5,406			6,992			110,560			3,126			170			113,856
(a)	Regulated Utilities recorded charges related to Duke Energy Indiana's Integrated Gasification Combined Cycle
(IGCC) project. See Note 4 for additional information about these charges. Regulated Utilities also recorded the reversal of expenses of $60 million, net of tax, related to a prior year Voluntary Opportunity Plan in accordance with Duke Energy Carolinas' 2011 rate case. See Note 19 for additional information about these expenses.
(b)	Other includes costs to achieve the Progress Energy merger. See Notes 2 and 25 for additional information about the merger and related costs.
Geographical Information
(in millions)	U.S.			Latin America(a)			Consolidated
2014
Consolidated revenues	$	22,508		$	1,417		$	23,925
Consolidated long-lived assets	80,709			2,458			83,167
2013
Consolidated revenues	$	21,211		$	1,545		$	22,756
Consolidated long-lived assets	78,581			2,781			81,362
2012
Consolidated revenues	$	16,366		$	1,546		$	17,912
Consolidated long-lived assets	79,144			2,467			81,611
(a)	Change in amounts of long-lived assets in Latin America includes foreign currency translation adjustments on property, plant and equipment and other long-lived asset balances.
Products and Services
(in millions)	Retail Electric			Wholesale Electric			Retail Natural Gas			Wholesale Natural Gas			Other			Total Revenues
2014
Regulated Utilities	$	19,007		$	1,879		$	571		$	—		$	814		$	22,271
International Energy	—			1,326			—			91			—			1,417
Commercial Power	—			255			—			—			—			255
Total Reportable Segments	$	19,007		$	3,460		$	571		$	91		$	814		$	23,943
2013
Regulated Utilities	$	17,837		$	1,720		$	506		$	—		$	847		$	20,910
International Energy	—			1,447			—			99			—			1,546
Commercial Power	—			260			—			—			—			260
Total Reportable Segments	$	17,837		$	3,427		$	506		$	99		$	847		$	22,716
2012
Regulated Utilities	$	13,773		$	1,120		$	470		$	—		$	717		$	16,080
International Energy	—			1,444			—			105			—			1,549
Commercial Power	—			307			—			—			—			307
Total Reportable Segments	$	13,773		$	2,871		$	470		$	105		$	717		$	17,936
Duke Energy Ohio
Duke Energy Ohio has two reportable operating segments, Regulated Utilities and Commercial Power.
Regulated Utilities transmits and distributes electricity in portions of Ohio and generates, distributes and sells electricity in portions of Kentucky. Regulated Utilities also transports and sells natural gas in portions of Ohio and northern Kentucky. It conducts operations primarily through Duke Energy Ohio and its wholly owned subsidiary, Duke Energy Kentucky.
As discussed in Note 2, Duke Energy entered into an agreement to sell Commercial Power's nonregulated Midwest generation business to Dynegy in a transaction that is expected to close in the second quarter of 2015. As a result of this divestiture, the results of operations of the nonregulated Midwest generation business have been reclassified to Discontinued Operations on the Consolidated Statements of Operations and Comprehensive Income. Amounts remaining in Commercial Power relate to assets not included in the Disposal Group. Certain costs such as interest and general and administrative expenses previously allocated to the Disposal Group were not reclassified to discontinued operations.
The remainder of Duke Energy Ohio’s operations is presented as Other. While it is not considered an operating segment, Other primarily includes certain governance costs allocated by its parent, Duke Energy. See Note 13 for additional information. All of Duke Energy Ohio’s revenues are generated domestically and its long-lived assets are all in the U.S.
	Year Ended December 31, 2014
(in millions)	Regulated Utilities			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
Unaffiliated revenues	$	1,894		$	19		$	1,913		$	—		$	—		$	1,913
Intersegment revenues	1			—			1			—			(1		)	—
Total revenues	$	1,895		$	19		$	1,914		$	—		$	(1	)	$	1,913
Interest expense	$	81		$	5		$	86		$	—		$	—		$	86
Depreciation and amortization	211			2			213			1			—			214
Income tax expense (benefit)	117			(67		)	50			(7		)	—			43
Segment income (loss)(a)	202			(121		)	81			(13		)	—			68
Income from discontinued operations, net of tax																(563		)
Net loss																$	(495	)
Capital expenditures	$	300		$	22		$	322		$	—		$	—		$	322
Segment assets	6,908			3,187			10,095			134			(230		)	9,999
(a)	Commercial Power recorded a pretax impairment charge of $94 million related to OVEC. See Note 11 for additional information.
	Year Ended December 31, 2013
(in millions)	Regulated Utilities			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
Unaffiliated revenues	$	1,765		$	40		$	1,805		$	—		$	—		$	1,805
Total revenues	$	1,765		$	40		$	1,805		$	—		$	—		$	1,805
Interest expense	$	74		$	—		$	74		$	—		$	—		$	74
Depreciation and amortization	200			13			213			—			—			213
Income tax expense (benefit)	91			(36		)	55			(12		)	—			43
Segment income (loss)	151			(65		)	86			(19		)	—			67
Income from discontinued operations, net of tax																35
Net income																$	102
Capital expenditures	$	375		$	58		$	433		$	—		$	—		$	433
Segment assets	6,649			4,170			10,819			99			(155		)	10,763
	Year Ended December 31, 2012
(in millions)	Regulated Utilities			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
Unaffiliated revenues	$	1,745		$	75		$	1,820		$	—		$	—		$	1,820
Intersegment revenues	1			1			2			—			(2		)	—
Total revenues	$	1,746		$	76		$	1,822		$	—		$	(2	)	$	1,820
Interest expense	$	61		$	28		$	89		$	—		$	—		$	89
Depreciation and amortization	179			16			195			—			—			195
Income tax expense (benefit)	91			(40		)	51			(18		)	—			33
Segment income (loss)	159			(80		)	79			(34		)	—			45
Income from discontinued operations, net of tax																130
Net income																$	175
Capital expenditures	$	427		$	87		$	514		$	—		$	—		$	514
Segment assets	6,434			4,175			10,609			117			(166		)	10,560
DUKE ENERGY CAROLINAS, PROGRESS ENERGY, DUKE ENERGY PROGRESS, DUKE ENERGY FLORIDA AND DUKE ENERGY INDIANA
Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana each have one reportable operating segment, Regulated Utility, which generates, transmits, distributes and sells electricity. The remainder of each company’s operations is classified as Other. While not considered a reportable segment for any of these companies, Other consists of certain unallocated corporate costs. Other for Progress Energy also includes interest expense on corporate debt instruments of $241 million, $300 million and $304 million for the years ended December 31, 2014, 2013 and 2012. The following table summarizes the net loss for Other for each of these entities.
	Years Ended December 31,
(in millions)	2014			2013			2012
Duke Energy Carolinas	$	(79	)	$	(97	)	$	(169	)
Progress Energy	(190		)	(241		)	(379		)
Duke Energy Progress	(31		)	(46		)	(139		)
Duke Energy Florida	(19		)	(24		)	(58		)
Duke Energy Indiana	(11		)	(16		)	(27		)
Duke Energy Progress earned approximately 11 percent of its consolidated operating revenues from North Carolina Electric Membership Corporation (NCEMC) in 2014. These revenues relate to wholesale contracts and transmission revenues. The respective Regulated Utility and Regulated Utilities operating segments own substantially all of Duke Energy Carolinas’, Progress Energy’s, Duke Energy Progress’, Duke Energy Florida’s and Duke Energy Indiana’s assets at December 31, 2014, 2013 and 2012.

Regulatory_Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2014
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS
	Regulatory Assets and Liabilities
	The Duke Energy Registrants record regulatory assets and liabilities that result from the ratemaking process. See Note 1 for further information.
	The following tables present the regulatory assets and liabilities recorded on the Consolidated Balance Sheets.
		December 31, 2014
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Assets
	Asset retirement obligations	$	3,017	$	907	$	1,882		$	1,584	$	298	$	—	$	—
	Accrued pension and OPEB	2,015		412		812			354		458		132		217
	Retired generation facilities	1,659		58		1,545			152		1,393		—		56
	Debt fair value adjustment	1,305		—		—			—		—		—		—
	Net regulatory asset related to income taxes	1,144		614		354			141		213		64		111
	Hedge costs and other deferrals	628		103		490			217		273		7		28
	Demand side management (DSM)/Energy efficiency (EE)	330		106		203			193		10		21		—
	Grid Modernization	76		—		—			—		—		76		—
	Vacation accrual	213		86		46			46		—		6		12
	Deferred fuel	246		50		182			138		44		9		5
	Nuclear deferral	296		141		155			43		112		—		—
	Post-in-service carrying costs and deferred operating expenses	494		124		121			28		93		21		228
	Gasification services agreement buyout	55		—		—			—		—		—		55
	Transmission expansion obligation	70		—		—			—		—		74		—
	Manufactured gas plant (MGP)	115		—		—			—		—		115		—
	Other	494		263		109			66		42		36		66
	Total regulatory assets	12,157		2,864		5,899			2,962		2,936		561		778
	Less: current portion	1,115		399		491			287		203		49		93
	Total non-current regulatory assets	$	11,042	$	2,465	$	5,408		$	2,675	$	2,733	$	512	$	685
		December 31, 2014
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Liabilities
	Costs of removal	$	5,221	$	2,420	$	1,975		$	1,692	$	283	$	222	$	613
	Amounts to be refunded to customers	166		—		70			—		70		—		96
	Storm reserve	150		25		125			—		125		—		—
	Accrued pension and OPEB	379		76		121			61		60		19		91
	Deferred fuel	37		6		23			23		—		—		8
	Other	444		217		171			127		44		10		42
	Total regulatory liabilities	6,397		2,744		2,485			1,903		582		251		850
	Less: current portion	204		34		106			71		35		10		54
	Total non-current regulatory liabilities	$	6,193	$	2,710	$	2,379		$	1,832	$	547	$	241	$	796
		December 31, 2013
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Assets
	Asset retirement obligations	$	1,608	$	123	786			$	389	$	397	$	—	$	—
	Accrued pension and OPEB	1,723		347		750			269		438		120		219
	Retired generation facilities	1,748		68		1,619			241		1,378		—		61
	Debt fair value adjustment	1,338		—		—			—		—		—		—
	Net regulatory asset related to income taxes	1,115		555		331			113		218		72		157
	Hedge costs and other deferrals	450		98		318			165		153		5		29
	DSM/EE	306		140		152			140		12		14		—
	Grid Modernization	65		—		—			—		—		65		—
	Vacation accrual	210		82		55			50		—		7		13
	Deferred fuel	94		—		37			6		31		14		43
	Nuclear deferral	262		40		222			77		145		—		—
	Post-in-service carrying costs and deferred operating expenses	459		150		137			19		118		21		151
	Gasification services agreement buyout	75		—		—			—		—		—		75
	Transmission expansion obligation	70		—		—			—		—		74		—
	MGP	90		—		—			—		—		90		—
	Other	473		219		101			42		60		46		87
	Total regulatory assets	10,086		1,822		4,508			1,511		2,950		528		835
	Less: current portion	895		295		353			127		221		57		118
	Total non-current regulatory assets	$	9,191	$	1,527	$	4,155		$	1,384	$	2,729	$	471	$	717
		December 31, 2013
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Liabilities
	Costs of removal	$	5,308	$	2,423	$	2,008		$	1,637	$	371	$	241	$	645
Amounts to be refunded to customers	151		—		120			—		120		—		31
Storm reserve	145		20		125			—		125		—		—
Accrued pension and OPEB	138		—		—			—		—		21		77
Deferred fuel	177		45		132			—		132		—		—
Other	346		153		114			99		14		27		45
Total regulatory liabilities	6,265		2,641		2,499			1,736		762		289		798
Less: current portion	316		65		207			63		144		27		16
Total non-current regulatory liabilities	$	5,949	$	2,576	$	2,292		$	1,673	$	618	$	262	$	782
Descriptions of regulatory assets and liabilities, summarized in the tables above, as well as their recovery and amortization periods follow. Items are excluded from rate base unless otherwise noted.
Asset retirement obligations. Represents legal obligations associated with the future retirement of property, plant and equipment. Asset retirement obligations relate primarily to decommissioning nuclear power facilities and closure of ash basins in North Carolina and South Carolina. No return is currently earned on these balances. The recovery period for costs related to nuclear facilities runs through the decommissioning period of each nuclear unit, the latest of which is currently estimated to be 2097. The recovery period for costs related to ash basin closures has not yet been determined. See Notes 1 and 9 for additional information.
Accrued pension and OPEB. Accrued pension and OPEB represent regulatory assets and liabilities related to each of the Duke Energy Registrants’ respective shares of unrecognized actuarial gains and losses, unrecognized prior service cost, and unrecognized transition obligation attributable to Duke Energy’s pension plans and OPEB plans. The regulatory asset or liability is amortized with the recognition of actuarial gains and losses, prior service cost, and transition obligations to net periodic benefit costs for pension and OPEB plans. See Note 21 for additional detail.
Retired generation facilities. Duke Energy Florida earns a reduced return on a substantial portion of the amount of regulatory asset associated with the retirement of Crystal River Unit 3 not included in rate base and a full return on a portion of the retired plant currently recovered in the nuclear cost recovery clause (NCRC). Once included in base rates the amount will be amortized over 20 years. Duke Energy Carolinas earns a return on the outstanding retail balance with recovery periods ranging from 5 to 10 years. Duke Energy Progress earns a return on the outstanding balance with recovery over a period of 10 years for retail purposes and over the longer of 10 years or the previously estimated planned retirement date for wholesale purposes. Duke Energy Indiana earns a return on the outstanding balances and the costs are included in rate base.
Debt fair value adjustment. Purchase accounting adjustment to restate the carrying value of Progress Energy debt to fair value. Amount is amortized over the life of the related debt.
Net regulatory asset related to income taxes. Regulatory assets principally associated with the depreciation and recovery of AFUDC equity. Amounts have no impact on rate base as regulatory assets are offset by deferred tax liabilities. The recovery period is over the life of the associated assets.
Hedge costs and other deferrals. Amounts relate to unrealized gains and losses on derivatives recorded as a regulatory asset or liability, respectively, until the contracts are settled. The recovery period varies for these costs, and currently extends to 2027.
DSM/EE. The recovery period varies for these costs, with some currently unknown. Duke Energy Carolinas, Duke Energy Progress, and Duke Energy Florida are required to pay interest on the outstanding liability balance. Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida collect a return on DSM/EE investments.
Grid Modernization. Represents deferred depreciation and operating expenses as well as carrying costs on the portion of capital expenditures placed in service but not yet reflected in retail rates as plant in service. Recovery period is generally one year for depreciation and operating expenses. Recovery for post-in-service carrying costs are over the life of the assets.
Vacation accrual. Generally recovered within one year.
Deferred fuel. Deferred fuel costs represent certain energy costs that are recoverable or refundable as approved by the applicable regulatory body. Duke Energy Florida amount includes capacity costs. Duke Energy Florida and Duke Energy Ohio earn a return on under-recovered costs. Duke Energy Florida and Duke Energy Ohio pay interest on over-recovered costs. Duke Energy Carolinas and Duke Energy Progress pay interest on over-recovered costs in North Carolina. Recovery period is generally over one year. Duke Energy Indiana recovery period is quarterly.
Nuclear deferral. Includes (i) amounts related to levelizing nuclear plant outage costs at Duke Energy Carolinas in North Carolina and South Carolina, and Duke Energy Progress in North Carolina, which allows for the recognition of nuclear outage expenses over the refueling cycle rather than when the outage occurs, resulting in the deferral of operations and maintenance costs associated with refueling and (ii) certain deferred preconstruction and carrying costs at Duke Energy Florida as approved by the FPSC primarily associated with Levy, currently expected to be recovered in revenues by the end of 2017.
Post-in-service carrying costs and deferred operating expenses. Represents deferred depreciation and operating expenses as well as carrying costs on the portion of capital expenditures placed in service but not yet reflected in retail rates as plant in service. Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana earn a return on the outstanding balance. Duke Energy Florida earns a return at a reduced rate. For Duke Energy Ohio and Duke Energy Indiana, some amounts are included in rate base. Recovery is over various lives, and the latest recovery period is 2081.
Gasification services agreement buyout. The IURC authorized Duke Energy Indiana to recover costs incurred to buyout a gasification services agreement, including carrying costs through 2018.
Transmission expansion obligation. Represents transmission expansion obligations related to Duke Energy Ohio’s withdrawal from Midcontinent Independent System Operator, Inc. (MISO).
MGP. Represents remediation costs for former MGP sites. In November 2013, the PUCO approved recovery of these costs through 2018. Duke Energy Ohio does not earn a return on these costs. See Note 5 for additional information.
Costs of removal. Represents funds received from customers to cover the future removal of property, plant and equipment from retired or abandoned sites as property is retired. Also includes certain deferred gains on NDTF investments.
Amounts to be refunded to customers. Represents required rate reductions to retail customers by the applicable regulatory body. The refund period is through 2016 for Duke Energy Florida and through 2017 for Duke Energy Indiana.
Storm reserve. Duke Energy Carolinas and Duke Energy Florida are allowed to petition the PSCSC and FPSC, respectively, to seek recovery of named storms. Funds are used to offset future incurred costs.
Restrictions on the Ability of Certain Subsidiaries to Make Dividends, Advances and Loans to Duke Energy
As a condition to the approval of merger transactions, the NCUC, PSCSC, PUCO, KPSC and IURC imposed conditions on the ability of Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio, Duke Energy Kentucky and Duke Energy Indiana to transfer funds to Duke Energy through loans or advances, as well as restricted amounts available to pay dividends to Duke Energy. Certain subsidiaries may transfer funds to Duke Energy Corporation Holding Company (the parent) by obtaining approval of the respective state regulatory commissions. These conditions imposed restrictions on the ability of the public utility subsidiaries to pay cash dividends as discussed below.
Duke Energy Progress and Duke Energy Florida also have restrictions imposed by their first mortgage bond indentures and Articles of Incorporation which, in certain circumstances, limit their ability to make cash dividends or distributions on common stock. Amounts restricted as a result of these provisions were not material at December 31, 2014.
Additionally, certain other subsidiaries of Duke Energy have restrictions on their ability to dividend, loan or advance funds to Duke Energy due to specific legal or regulatory restrictions, including, but not limited to, minimum working capital and tangible net worth requirements.
Duke Energy Carolinas
Duke Energy Carolinas must limit cumulative distributions subsequent to mergers to (i) the amount of retained earnings on the day prior to the closing of the mergers, plus (ii) any future earnings recorded.
Duke Energy Progress
Duke Energy Progress must limit cumulative distributions subsequent to the merger between Duke Energy and Progress Energy to (i) the amount of retained earnings on the day prior to the closing of the merger, plus (ii) any future earnings recorded.
Duke Energy Ohio
Duke Energy Ohio will not declare and pay dividends out of capital or unearned surplus without the prior authorization of the PUCO. Duke Energy Ohio received FERC and PUCO approval to pay dividends from its equity accounts that are reflective of the amount that it would have in its retained earnings account had push-down accounting for the Cinergy Corp. (Cinergy) merger not been applied to Duke Energy Ohio’s balance sheet. The conditions include a commitment from Duke Energy Ohio that equity, adjusted to remove the impacts of push-down accounting, will not fall below 30 percent of total capital.
Duke Energy Kentucky is required to pay dividends solely out of retained earnings and to maintain a minimum of 35 percent equity in its capital structure.
Duke Energy Indiana
Duke Energy Indiana must limit cumulative distributions subsequent to the merger between Duke Energy and Cinergy to (i) the amount of retained earnings on the day prior to the closing of the merger, plus (ii) any future earnings recorded. In addition, Duke Energy Indiana will not declare and pay dividends out of capital or unearned surplus without prior authorization of the IURC.
The restrictions discussed above were less than 25 percent of Duke Energy's net assets at December 31, 2014.
Rate Related Information
The NCUC, PSCSC, FPSC, IURC, PUCO and KPSC approve rates for retail electric and natural gas services within their states. The FERC approves rates for electric sales to wholesale customers served under cost-based rates (excluding Ohio and Indiana), as well as sales of transmission service.
Duke Energy Carolinas
2013 North Carolina Rate Case
On September 24, 2013, the NCUC approved a settlement agreement related to Duke Energy Carolinas’ request for a rate increase with minor modifications. The NCUC Public Staff (Public Staff) was a party to the settlement. The settling parties agreed to a three-year step-in rate increase, with the first two years providing for $204 million, or a 4.5 percent average increase in rates, and the third year providing for rates to be increased by an additional $30 million, or 0.6 percent. The agreement is based upon a return on equity of 10.2 percent and an equity component of the capital structure of 53 percent. The settlement agreement (i) allows for the recognition of nuclear outage expenses over the refueling cycle rather than when the outage occurs, (ii) a $10 million shareholder contribution to agencies that provide energy assistance to low-income customers, and (iii) an annual reduction in the regulatory liability for costs of removal of $30 million for each of the first two years. Duke Energy Carolinas has agreed not to request additional base rate increases to be effective before September 2015. New rates went into effect on September 25, 2013.
On October 23, 2013, the North Carolina Attorney General (NCAG) appealed the rate of return and capital structure approved in the agreement. The NC Waste Awareness and Reduction Network (NC WARN) appealed various matters in the settlement on October 24, 2013. The North Carolina Supreme Court (NCSC) denied a motion to consolidate these appeals with other North Carolina rate case appeals involving Duke Energy Carolinas and Duke Energy Progress on March 13, 2014. Briefing concluded in this matter and oral argument occurred on September 8, 2014. On January 23, 2015, the NCSC affirmed the NCUC's September 24, 2013 order.
2013 South Carolina Rate Case
On September 11, 2013, the PSCSC approved a settlement agreement related to Duke Energy Carolinas’ request for a rate increase. Parties to the settlement agreement were the Office of Regulatory Staff, Wal-Mart Stores East, LP and Sam’s East, Incorporated, the South Carolina Energy Users Committee, Public Works of the City of Spartanburg, South Carolina and the South Carolina Small Business Chamber of Commerce. The parties agreed to a two-year step-in rate increase, with the first year providing for approximately $80 million, or a 5.5 percent average increase in rates, and the second year providing for rates to be increased by an additional $38 million, or 2.6 percent. The settlement agreement is based upon a return on equity of 10.2 percent and a 53 percent equity component of the capital structure. The settlement agreement (i) allows for the recognition of nuclear outage expenses over the refueling cycle rather than when the outage occurs, (ii) approximately $4 million of contributions to agencies that provide energy assistance to low-income customers and for economic development, and (iii) a reduction in the regulatory liability for costs of removal of $45 million for the first year. Duke Energy Carolinas has agreed not to request additional base rate increases to be effective before September 2015. New rates went into effect on September 18, 2013.
2011 North Carolina Rate Case
On January 27, 2012, the NCUC approved a settlement agreement related to Duke Energy Carolinas’ request for a rate increase. On October 23, 2013, the NCUC issued a second order in the case reaffirming the rate of return approved in the settlement agreement, in response to an appeal by the NCAG. On November 21, 2013, the NCAG appealed the NCUC's October 2013 order. On December 19, 2014, the NCSC affirmed the NCUC's October 2013 order concluding the appeal.
William States Lee Combined Cycle Facility
On April 9, 2014, the PSCSC granted Duke Energy Carolinas and NCEMC a Certificate of Environmental Compatibility and Public Convenience and Necessity (CECPCN) for the construction and operation of a 750 MW combined cycle natural gas-fired generating plant at its existing William States Lee Generating Station in Anderson, South Carolina. On May 16, 2014, Duke Energy Carolinas announced its intention to begin construction in summer 2015 and estimated a cost to build of $600 million for its share of the facility, including AFUDC. The project is expected to be commercially available in late 2017. NCEMC will own approximately 13 percent of the project. On July 3, 2014, the South Carolina Coastal Conservation League and Southern Alliance for Clean Energy jointly filed a Notice of Appeal with the Court of Appeals of South Carolina seeking the court's review of the PSCSC's decision. Duke Energy Carolinas' initial brief in support of the PSCSC's order granting the CECPCN was filed on January 12, 2015. Duke Energy Carolinas cannot predict the outcome of this matter.
William States Lee III Nuclear Station
In December 2007, Duke Energy Carolinas applied to the NRC for a COL for two Westinghouse AP1000 (advanced passive) reactors for the proposed William States Lee III Nuclear Station (Lee Nuclear Station) at a site in Cherokee County, South Carolina. Submitting the COL application did not commit Duke Energy Carolinas to build nuclear units. Through several separate orders, the NCUC and PSCSC concurred with the prudency of Duke Energy Carolinas incurring certain project development and pre-construction costs, although recovery of costs is not guaranteed. Duke Energy Carolinas has incurred approximately $427 million, including AFUDC through December 31, 2014. This amount is included in Net property, plant and equipment on Duke Energy Carolinas’ Consolidated Balance Sheets.
Design changes have been identified in the Westinghouse AP1000 certified design that must be addressed before NRC can complete its review of the Lee Nuclear Station COL application. These design changes set the schedule for completion of the NRC COL application review and issuance of the Lee COL. Receipt of the Lee Nuclear Station COL is currently expected by mid-2016.
Duke Energy Progress
2012 North Carolina Rate Case
On May 30, 2013, the NCUC approved a settlement agreement related to Duke Energy Progress’ request for a rate increase. The Public Staff was a party to the settlement agreement. The settling parties agreed to a two-year step-in rate increase, with the first year providing for a $147 million, or a 4.5 percent average increase in rates, and the second year providing for rates to be increased by an additional $31 million, or a 1.0 percent average increase in rates. The agreement is based upon a return on equity of 10.2 percent and an equity component of the capital structure of 53 percent. The settlement agreement (i) allows for the recognition of nuclear outage expenses over the refueling cycle rather than when the outage occurs, (ii) a $20 million shareholder contribution to agencies that provide energy assistance to low-income customers, and (iii) a reduction in the regulatory liability for costs of removal of $20 million for the first year. The initial rate increase went into effect on June 1, 2013 and the step-in rate increase went into effect in June 2013.
On July 1, 2013, the NCAG appealed the NCUC’s approval of the rate of return and capital structure included in the agreement. NC WARN also appealed various matters in the settlement. On August 20, 2014, the NCSC affirmed the NCUC's order approving Duke Energy Progress' rate of return and capital structure concluding the appeal.
L.V. Sutton Combined Cycle Facility
Duke Energy Progress completed construction of a 625 MW combined cycle natural gas-fired generating facility at its existing L.V. Sutton Steam Station (Sutton) in New Hanover County, North Carolina. Sutton began commercial operations in the fourth quarter of 2013.
Shearon Harris Nuclear Station Expansion
In 2006, Duke Energy Progress selected a site at Harris to evaluate for possible future nuclear expansion. On February 19, 2008, Duke Energy Progress filed its COL application with the NRC for two Westinghouse AP1000 reactors at Harris, which the NRC docketed for review. On May 2, 2013, Duke Energy Progress filed a letter with the NRC requesting the NRC to suspend its review activities associated with the COL at the Harris site. As a result of the decision to suspend the COL applications, during the second quarter of 2013, Duke Energy Progress recorded a pretax impairment charge of $22 million which represented costs associated with the COL, which were not probable of recovery. As of December 31, 2014, approximately $48 million is recorded in Regulatory assets on Duke Energy Progress’ Consolidated Balance Sheets.
Wholesale Depreciation Rates
On April 19, 2013, Duke Energy Progress filed an application with FERC for acceptance of changes to generation depreciation rates and in August 2013 filed for acceptance of additional changes. These changes affect the rates of Duke Energy Progress' wholesale power customers that purchase or will purchase power under formula rates. Certain Duke Energy Progress wholesale customers filed interventions and protests. FERC accepted the depreciation rate changes, subject to refund, and set the matter for settlement and hearing in a consolidated proceeding. FERC further initiated an action with respect to the justness and reasonableness of the proposed rate changes. Settlement was reached in October 2014 for changes to the depreciation rates and conforming changes to the wholesale formula rates. FERC approved the settlement in December 2014. The agreement will have no material or adverse impact to the rates originally proposed by Duke Energy Progress, and Duke Energy Progress will receive cost recovery for early retired plants previously included in the depreciation rates.
Duke Energy Florida
FERC Transmission Return on Equity Complaint
On February 12, 2012, Seminole Electric Cooperative, Inc. and Florida Municipal Power Agency filed with FERC a complaint against Duke Energy Florida alleging that the current rate of return on equity in Duke Energy Florida's transmission formula rates of 10.8 percent is unjust and unreasonable and should be reduced to 9.02 percent. The complainants further alleged that return on equity adjustments should take effect retroactive to January 1, 2010 under the governing transmission formula rate protocols. On May 13, 2013, the complainants filed a second complaint alleging that the return on equity should be reduced to 8.63 percent or 8.84 percent. On June 19, 2014, FERC issued orders consolidating the two complaints, setting them for settlement and hearing procedures, setting refund effective dates of February 29, 2012 for the first complaint and May 13, 2013 for the second complaint, and setting for settlement and hearing the issue of whether return on equity adjustments should take effect prior to the refund effective date of the first complaint. On August 12, 2014, the complainants filed a third complaint alleging that the return on equity should be 8.69 percent. On December 5, 2014, FERC issued an order consolidating the third complaint with the first two complaints for the purposes of settlement, hearing, and decision, and establishing a refund effective date of August 12, 2014 for the third complaint. The parties are engaged in settlement discussions. Duke Energy Florida cannot predict the outcome of this matter.
FPSC Settlement Agreements
On February 22, 2012, the FPSC approved a settlement agreement (the 2012 Settlement) among Duke Energy Florida, the Florida Office of Public Counsel (OPC) and other customer advocates. The 2012 Settlement was to continue through the last billing cycle of December 2016. On October 17, 2013, the FPSC approved a settlement agreement (the 2013 Settlement) between Duke Energy Florida, OPC, and other customer advocates. The 2013 Settlement replaces and supplants the 2012 Settlement and substantially resolves issues related to (i) Crystal River Unit 3, (ii) Levy, (iii) Crystal River 1 and 2 coal units, and (iv) future generation needs in Florida. Refer to the remaining sections below for further discussion of these settlement agreements.
Crystal River Unit 3
On February 5, 2013, Duke Energy Florida announced the retirement of Crystal River Unit 3. On February 20, 2013, Duke Energy Florida filed with the NRC a certification of permanent cessation of power operations and permanent removal of fuel from the reactor vessel. In December 2013, and March 2014, Duke Energy Florida filed an updated site-specific decommissioning plan with the NRC and FPSC, respectively. The plan, which was approved by the FPSC in November 2014, included a decommissioning cost estimate of $1,180 million, including amounts applicable to joint owners, under the SAFSTOR option. Duke Energy Florida’s decommissioning study assumes Crystal River Unit 3 will be in SAFSTOR configuration, requiring limited staffing to monitor plant conditions, until the eventual dismantling and decontamination activities to be completed by 2073. This decommissioning approach is currently utilized at a number of retired domestic nuclear power plants and is one of three accepted approaches to decommissioning approved by the NRC.
Duke Energy Florida has reclassified all Crystal River Unit 3 investments, including property, plant and equipment, nuclear fuel, inventory, and other assets, to a regulatory asset. Duke Energy agreed to forgo recovery of $295 million of regulatory assets and an impairment charge was recorded in the second quarter of 2013 for this matter. Duke Energy Florida is allowed to accelerate cash recovery of approximately $130 million of the Crystal River Unit 3 regulatory asset from retail customers from 2014 through 2016 through its fuel clause. Duke Energy Florida will begin recovery of the remaining Crystal River Unit 3 regulatory asset, up to a cap of $1,466 million from retail customers upon the earlier of (i) full recovery of the uncollected Levy investment or (ii) the first billing period of January 2017. Recovery will continue 240 months from inception of collection of the regulatory asset in base rates. The Crystal River Unit 3 base rate component will be adjusted at least every four years.
Included in this recovery, but not subject to the cap, are costs of building an independent spent fuel storage installation (ISFSI). The return rate will be based on the currently approved AFUDC rate with a return on equity of 7.35 percent, or 70 percent of the currently approved 10.5 percent. The return rate is subject to change if the return on equity changes in the future. In December 2014, the FPSC approved Duke Energy Florida's decision to construct the ISFSI and approved Duke Energy Florida's request to defer amortization of the ISFSI pending resolution of its litigation against the federal government as a result of the Department of Energy's breach of its obligation to accept spent nuclear fuel. The regulatory asset associated with the original power uprate project to increase generating capacity will continue to be recovered through the Nuclear Cost Recovery Clause over an estimated seven-year period that began in 2013.
Through December 31, 2014, Duke Energy Florida deferred $1,377 million for rate recovery related to Crystal River Unit 3, which is subject to the rate recovery cap in the 2013 Settlement. In addition, Duke Energy Florida deferred $260 million for recovery associated with building an ISFSI and the original uprate project, which is not subject to the rate recovery cap discussed above. Duke Energy Florida does not expect the Crystal River Unit 3 costs to exceed the cap.
Customer Rate Matters
Pursuant to the 2013 Settlement, Duke Energy Florida will maintain base rates at the current level through the last billing period of 2018, subject to the return on equity range of 9.5 percent to 11.5 percent, with exceptions for base rate increases for the recovery of the Crystal River Unit 3 regulatory asset beginning no later than 2017 and base rate increases for new generation through 2018, per the provisions of the 2013 Settlement. Duke Energy Florida is not required to file a depreciation study, fossil dismantlement study or nuclear decommissioning study until the earlier of the next rate case filing or March 31, 2019. The 2012 Settlement provided for a $150 million increase in base revenue effective with the first billing cycle of January 2013. Costs associated with Crystal River Unit 3 investments were removed from retail rate base effective with the first billing cycle of January 2013. Duke Energy Florida is accruing, for future rate-setting purposes, a carrying charge on the Crystal River Unit 3 investment until the Crystal River Unit 3 regulatory asset is recovered in base rates. If Duke Energy Florida’s retail base rate earnings fall below the return on equity range, as reported on a FPSC-adjusted or pro forma basis on a monthly earnings surveillance report, it may petition the FPSC to amend its base rates during the term of the 2013 Settlement.
Duke Energy Florida agreed to refund $388 million to retail customers through its fuel clause, as required by the 2012 Settlement. At December 31, 2014, $120 million remains to be refunded, of which $50 million credit is recorded in Regulatory assets within Current Assets as an offset to deferred fuel and $70 million is recorded in Regulatory liabilities in Deferred Credits and Other Liabilities on the Consolidated Balance Sheets.
Levy
On July 28, 2008, Duke Energy Florida applied to the NRC for a COL for two Westinghouse AP1000 reactors at Levy. In 2008, the FPSC granted Duke Energy Florida’s petition for an affirmative Determination of Need and related orders requesting cost recovery under Florida’s nuclear cost-recovery rule, together with the associated facilities, including transmission lines and substation facilities. Design changes have been identified in the Westinghouse AP1000 certified design that must be addressed before the NRC can complete its review of the Levy COL application. These design changes set the schedule for completion of the NRC COL application review and issuance of the Levy COL. Based on the current review schedule, the Levy COL is currently expected by mid-2016.
On January 28, 2014, Duke Energy Florida terminated the Levy engineering, procurement and construction agreement (EPC). Duke Energy Florida may be required to pay for work performed under the EPC and to bring existing work to an orderly conclusion, including but not limited to costs to demobilize and cancel certain equipment and material orders placed. As of December 31, 2014, Duke Energy Florida has recorded an exit obligation of $25 million for the termination of the EPC. This liability was recorded within Other in Deferred Credits and Other Liabilities with an offset primarily to Regulatory assets on the Consolidated Balance Sheets. Duke Energy Florida is allowed to recover reasonable and prudent EPC cancellation costs from its retail customers.
The 2012 Settlement provided that Duke Energy Florida include the allocated wholesale cost of Levy as a retail regulatory asset and include this asset as a component of rate base and amortization expense for regulatory reporting. In accordance with the 2013 Settlement, Duke Energy Florida ceased amortization of the wholesale allocation of Levy investments against retail rates. In the second quarter of 2013, Duke Energy Florida recorded a pretax charge of $65 million to write off the wholesale portion of Levy investments. This amount is included in Impairment charges on Duke Energy Florida's Statements of Operations and Comprehensive Income.
On October 27, 2014, the FPSC approved Duke Energy Florida rates for 2015 for Levy as filed and consistent with those established in the 2013 Revised and Restated Settlement Agreement. Recovery of the remaining retail portion of the project costs may occur over five years from 2013 through 2017. Duke Energy Florida has an ongoing responsibility to demonstrate prudency related to the wind down of the Levy investment and the potential for salvage of Levy assets. As of December 31, 2014, Duke Energy Florida has a net uncollected investment in Levy of approximately $180 million, including AFUDC. Of this amount, $91 million related to land and the COL is included in Net, property, plant and equipment and will be recovered through base rates and $89 million is included in Regulatory assets within Current Assets on the Consolidated Balance Sheets and will be recovered through the NCRC.
Crystal River 1 and 2 Coal Units
Duke Energy Florida has evaluated Crystal River 1 and 2 coal units for retirement in order to comply with certain environmental regulations. Based on this evaluation, those units will likely be retired by 2018. Once those units are retired Duke Energy Florida will continue recovery of existing annual depreciation expense through the end of 2020. Beginning in 2021, Duke Energy Florida will be allowed to recover any remaining net book value of the assets from retail customers through the Capacity Cost Recovery Clause. In April 2014, the FPSC approved Duke Energy Florida's petition to allow for the recovery of prudently incurred costs to comply with the Mercury and Air Toxics Standard through the Environmental Cost Recovery Clause.
New Generation
The 2013 Settlement establishes a recovery mechanism for additional generation needs. This recovery mechanism, the Generation Base Rate Adjustment, allows recovery of prudent costs of these items through an increase in base rates, upon the in-service date of such assets, without a general rate case at a 10.5 percent return on equity.
On May 27, 2014, Duke Energy Florida petitioned the FPSC for a Determination of Need to (i) construct a 1,640 MW combined cycle natural gas plant in Citrus County, Florida to be in service in 2018 with an estimated cost of $1.5 billion, (ii) construct a 320 MW combustion turbine plant at its existing Suwannee generating facility (Suwannee project) with an estimated cost of $197 million, and (iii) add inlet chilling to its existing Hines Energy Complex (Hines) combined cycle units which will increase the output of those units by 220 MW at an estimated cost of $160 million. These cost estimates include AFUDC. On August 26, 2014, Duke Energy Florida requested the FPSC withdraw consideration for the Suwannee project so that Duke Energy Florida could pursue further negotiations on an alternative power plant acquisition. On October 2, 2014, the FPSC approved the requests for the Citrus County plant and the uprate project at the Hines facility. Additional environmental and governmental approvals will be sought for the Citrus County project. The Hines uprate project is expected to be completed no later than 2017.
In December 2014, Duke Energy Florida and Osprey Energy Center, LLC, a wholly owned subsidiary of Calpine Corporation (Calpine) entered into an Asset Purchase and Sale Agreement for the purchase of a 599 MW combined cycle natural gas plant in Auburndale, Florida (Osprey Plant acquisition) for approximately $166 million. Closing is subject to the approval of FERC, FPSC and the expiration of the Hart Scott Rodino waiting period and is expected to occur by the first quarter of 2017 upon the expiration of an existing Power Purchase Agreement between Calpine and Duke Energy Florida. On January 30, 2015, Duke Energy Florida filed a petition with the FPSC requesting a determination that the Osprey Plant acquisition or, alternatively, the Suwannee project is the most cost effective generation alternative to meet Duke Energy Florida's remaining need prior to 2018.
Cost of Removal Reserve
The 2012 Settlement and the 2013 Settlement provide Duke Energy Florida the discretion to reduce cost of removal amortization expense for a certain portion of the cost of removal reserve until the earlier of its applicable cost of removal reserve reaches zero or the expiration of the 2013 Settlement. Duke Energy Florida may not reduce amortization expense if the reduction would cause it to exceed the appropriate high point of the return on equity range. Duke Energy Florida recognized a reduction in amortization expense of $114 million, and $178 million for the years ended December 31, 2013, and 2012 respectively. Duke Energy Florida had no cost of removal reserves eligible for amortization to income remaining at December 31, 2013.
Duke Energy Ohio
W.C. Beckjord Fuel Release
On August 18, 2014, approximately 9,000 gallons of fuel oil were inadvertently discharged into the Ohio River during a fuel oil transfer at the W.C. Beckjord generating plant. The Ohio Environmental Protection Agency (Ohio EPA) issued a Notice of Violation related to the discharge. Duke Energy Ohio is cooperating with the Ohio EPA, the EPA and the U.S. Attorney for the Southern District of Ohio, responding to a Request for Information from the EPA. No Notice of Violation has been issued by the EPA and no civil or criminal penalty amount has been established. Total repair and remediation costs related to the release are not expected to be material. Other costs related to the release, including state or federal civil enforcement proceedings, cannot be reasonably estimated at this time.
2014 Electric Security Plan (ESP)
On May 29, 2014, Duke Energy Ohio filed an application for approval of an SSO in the form of an ESP, effective June 1, 2015. The proposed ESP includes a competitive procurement process for SSO load, a distribution capital investment rider, a tracking mechanism for incremental distribution costs caused by major storms, and a cost-based recovery of Duke Energy Ohio’s contractual entitlement in OVEC. The proposed plan also seeks rate design modifications and continuance, revision, or termination of existing riders. An evidentiary hearing in this case concluded in November 2014 and final briefs were submitted in December 2014. Duke Energy Ohio cannot predict the outcome of this matter.
Capacity Rider Filing
On August 29, 2012, Duke Energy Ohio applied to the PUCO for the establishment of a charge for capacity provided pursuant to its obligations as a Fixed Resource Requirement entity. The charge, which was consistent with Ohio’s state compensation mechanism, was estimated to be approximately $729 million, and reflected Duke Energy Ohio’s embedded cost of capacity. On February 13, 2014, the PUCO denied Duke Energy Ohio’s request.
2012 Electric Rate Case
On May 1, 2013, the PUCO approved a settlement agreement between Duke Energy Ohio and all intervening parties (the Electric Settlement) related to Duke Energy Ohio’s electric distribution rate case. The Electric Settlement provides for a net increase in electric distribution revenues of $49 million, or an average increase of 2.9 percent, based upon a return on equity of 9.84 percent. Revised rates were effective in May 2013.
2012 Natural Gas Rate Case
On November 13, 2013, the PUCO issued an order approving a settlement among Duke Energy Ohio, the PUCO Staff and intervening parties (the Gas Settlement). The Gas Settlement provided for (i) no increase in base rates for natural gas distribution service and (ii) a return on equity of 9.84 percent. The Gas Settlement provided for a subsequent hearing on Duke Energy Ohio’s request for rider recovery of environmental remediation costs associated with its former MGP sites. After the conclusion of the evidentiary hearing and briefs, the PUCO authorized Duke Energy Ohio to recover $56 million, excluding carrying costs, of environmental remediation costs. The MGP rider became effective in April 2014 for a five-year period. On March 31, 2014, Duke Energy Ohio filed an application with the PUCO to adjust the MGP rider for investigation and remediation costs incurred in 2013. As of December 31, 2014, Duke Energy Ohio has a balance of $115 million in Regulatory assets in the Consolidated Balance Sheets related to MGP sites which includes the $56 million authorized for recovery in the rate case.
On May 14, 2014, the Ohio Supreme Court granted certain consumer groups' motion to stay the MGP rider pending their appeals of the PUCO approval of the Gas Settlement and Duke Energy Ohio suspended billing of the MGP rider in June 2014. Amounts collected under the rider prior to suspension were immaterial. The appellants, the PUCO and Duke Energy Ohio all filed briefs addressing the merits of this matter with the Ohio Supreme Court. On July 29, 2014, the Ohio Supreme Court denied Duke Energy Ohio's motion to lift the stay, but required appellants to post a bond. The Ohio Supreme Court also requested briefs on the appropriate amount of the bond. On November 5, 2014, the Ohio Supreme Court ordered the Appellants to post a bond of approximately $2.5 million to continue the stay of the rider. The bond was to be posted within ten days or the stay would be lifted. The Appellants failed to post the required bond and on November 18, 2014, Duke Energy Ohio requested the PUCO to reinstate the MGP rider. The PUCO approved reinstatement of the rider on January 15, 2015 and Duke Energy Ohio began billings of the MGP rider. Duke Energy Ohio cannot predict the outcome of the appeals in this matter.
Regional Transmission Organization (RTO) Realignment
Duke Energy Ohio, including Duke Energy Kentucky, transferred control of its transmission assets from MISO to PJM, effective December 31, 2011.
On December 22, 2010, the KPSC approved Duke Energy Kentucky’s request to effect the RTO realignment, subject to a commitment not to seek double-recovery in a future rate case of the transmission expansion fees that may be charged by MISO and PJM in the same period or overlapping periods.
On May 25, 2011, the PUCO approved a settlement between Duke Energy Ohio, Ohio Energy Group, the Office of the Ohio Consumers’ Counsel and the PUCO Staff related to Duke Energy Ohio’s recovery of certain costs of the RTO realignment via a non-bypassable rider. Duke Energy Ohio is allowed to recover all MISO Transmission Expansion Planning (MTEP) costs, including but not limited to Multi Value Project (MVP) costs, directly or indirectly charged to Ohio customers. Duke Energy Ohio also agreed to vigorously defend against any charges for MVP projects from MISO.
Upon its exit from MISO on December 31, 2011, Duke Energy Ohio recorded a liability for its exit obligation and share of MTEP costs, excluding MVP. This liability was recorded within Other in Current liabilities and Other in Deferred credits and other liabilities on Duke Energy Ohio’s Consolidated Balance Sheets.
The following table provides a reconciliation of the beginning and ending balance of Duke Energy Ohio’s recorded obligations related to its withdrawal from MISO. As of December 31, 2014, $74 million is recorded as a Regulatory asset on Duke Energy Ohio's Consolidated Balance Sheets.
(in millions)	31-Dec-13		Provision / Adjustments		Cash Reductions			31-Dec-14
Duke Energy Ohio	$	95	$	3	$	(4	)	$	94
MVP. MISO approved 17 MVP proposals prior to Duke Energy Ohio’s exit from MISO on December 31, 2011. Construction of these projects is expected to continue through 2020. Costs of these projects, including operating and maintenance costs, property and income taxes, depreciation and an allowed return, are allocated and billed to MISO transmission owners.
On December 29, 2011, MISO filed a tariff with the FERC providing for the allocation of MVP costs to a withdrawing owner based on monthly energy usage. The FERC set for hearing (i) whether MISO’s proposed cost allocation methodology to transmission owners who withdrew from MISO prior to January 1, 2012, is consistent with the tariff at the time of their withdrawal from MISO, and, (ii) if not, what the amount of and methodology for calculating any MVP cost responsibility should be. On July 16, 2013, a FERC Administrative Law Judge (ALJ) issued an initial decision. Under this initial decision, Duke Energy Ohio would be liable for MVP costs. Duke Energy Ohio filed exceptions to the initial decision, requesting the FERC overturn the ALJ’s decision. After reviewing the initial decision, along with all exceptions and responses filed by the parties, the FERC will issue a final decision. Duke Energy Ohio fully intends to appeal to the federal court of appeals if the FERC affirms the ALJ’s decision. Duke Energy Ohio cannot predict the outcome of these proceedings.
In 2012, MISO estimated Duke Energy Ohio’s MVP obligation over the period from 2012 to 2071 at $2.7 billion, on an undiscounted basis. The estimated obligation is subject to great uncertainty including the ultimate cost of the projects, the annual costs of operations and maintenance, taxes and return over the project lives, the number of years in service for the projects and the allocation to Duke Energy Ohio.
Any liability related to the MISO MVP matter attributable to the Disposal Group will not be transferred to Dynegy upon closing of the disposal of the Midwest generation business.
FERC Transmission Return on Equity and MTEP Cost Settlement
On October 14, 2011, Duke Energy Ohio and Duke Energy Kentucky submitted with FERC proposed modifications to the PJM Interconnection Open Access Transmission Tariff pertaining to recovery of the transmission revenue requirement as PJM transmission owners. The filing was made in connection with the Duke Energy Ohio's and Duke Energy Kentucky's move from MISO to PJM effective January 1, 2012. On April 24, 2012, FERC issued an order accepting the proposed filing effective January 1, 2012, except that the order denied a request to recover certain costs associated with the move from MISO to PJM without prejudice to the right to submit another filing seeking such recovery and including certain additional evidence, and set the rate of return on equity of 12.38 percent for settlement and hearing. A February 2013 settlement agreement filed with the FERC was rejected in September 2013. On October 30, 2014, the companies and six PJM transmission customers with load in the Duke Energy Ohio and Duke Energy Kentucky zone filed with FERC for approval of another settlement agreement. The principal terms of the settlement agreement are that, effective upon the date of FERC approval, (i) the return on equity will be reduced from 12.38 percent to 11.38 percent and (ii) Duke Energy Ohio and Duke Energy Kentucky will recover 30 percent of costs arising from their obligation to pay any portion of the costs of projects included in any MTEP that was approved prior to the date of the Duke Energy Ohio's and Duke Energy Kentucky's integration into PJM. The settlement is pending FERC approval. Duke Energy Ohio and Duke Energy Kentucky cannot predict the outcome of this matter
Duke Energy Indiana
Edwardsport IGCC Plant
On November 20, 2007, the IURC granted Duke Energy Indiana a Certificate of Public Convenience and Necessity for the construction of a 618 MW IGCC power plant at Duke Energy Indiana’s existing Edwardsport Generating Station in Knox County, Indiana with a cost estimate of $1.985 billion assuming timely recovery of financing costs related to the project. The Citizens Action Coalition of Indiana, Inc., Sierra Club, Inc., Save the Valley, Inc., and Valley Watch, Inc. (collectively, the Joint Intervenors) were intervenors in several matters related to the Edwardsport IGCC Plant.
On December 27, 2012, the IURC approved a settlement agreement (the 2012 Edwardsport settlement) related to the cost increase for the construction of the project, including subdockets before the IURC related to the project. The Office of Utility Consumer Counselor (OUCC), the Duke Energy Indiana Industrial Group and Nucor Steel-Indiana were parties to the settlement. The settlement agreement, as approved, capped costs to be reflected in customer rates at $2.595 billion, including estimated AFUDC through June 30, 2012. Duke Energy Indiana is allowed to recover AFUDC after June 30, 2012, until customer rates are revised, with such recovery decreasing to 85 percent on AFUDC accrued after November 30, 2012.
Over the course of construction of the project to date, Duke Energy Indiana has recorded pretax charges of approximately $897 million related to the project and the settlement agreement discussed above. Of this amount, pretax impairment and other charges of $631 million were recorded during the year ended December 31, 2012. These charges were recorded in Impairment charges and Operations, maintenance and other on Duke Energy Indiana's Consolidated Statements of Operations and Comprehensive Income.
The project was placed in commercial operation in June 2013. Costs for the Edwardsport IGCC plant are recovered from retail electric customers through a tracking mechanism, the IGCC rider. Updates to the IGCC rider are filed semi-annually. An order on the eleventh semi-annual IGCC rider is currently pending. The twelfth and thirteenth semi-annual IGGC riders were combined into one proceeding. In this proceeding, the OUCC, Duke Energy Indiana Industrial Group and Joint Intervenors alleged the Edwardsport IGCC plant was not properly placed in commercial operation in June 2013 and therefore operating and maintenance costs for the time period June 2013 through March 2014 should not be recoverable. The Duke Energy Indiana Industrial Group and Joint Intervenors also argued that the plant's performance was unsatisfactory during the first ten months of operations and recommended cost recovery disallowances. Evidentiary hearings concluded in February 2015 and an order is expected in the second half of 2015.
On March 18, 2014, the Indiana Court of Appeals denied an appeal filed by the Joint Intervenors and affirmed the IURC order approving the 2012 Edwardsport settlement and other related regulatory orders. On June 5, 2014, the Indiana Court of Appeals affirmed the decision on rehearing. The Joint Intervenors requested to seek transfer to the Indiana Supreme Court. On November 7, 2014, the Indiana Supreme Court denied the Joint Intervenors' request to transfer the appeal of these proceedings. The ninth and tenth semi-annual IGCC rider orders have also been appealed. On August 21, 2014, the Indiana Court of Appeals affirmed the IURC order in the tenth IGCC rider proceeding, and on October 29, 2014, denied Joint Intervenors' request for rehearing. The Joint Intervenors have requested a transfer of the matter to the Indiana Supreme Court. On September 8, 2014, the Indiana Court of Appeals remanded the IURC order in the ninth IGCC rider proceeding back to the IURC for further findings concerning approximately $61 million of financing charges Joint Intervenors claimed were caused by construction delay and a ratemaking issue concerning the in-service date determination for tax purposes. On February 25, 2015, the IURC issued an order on remand that upheld its prior order and added additional findings on the two issues as requested by the Indiana Court of Appeals. First, the IURC concluded the schedule delays in the construction of the IGCC plant were not the result of imprudence or unreasonable actions by Duke Energy Indiana and therefore recovery of the financing costs were appropriate. On the second issue, the IURC determined the federal tax in-service determination was to be made by the Internal Revenue Service, not the IURC, and the IURC appropriately reviewed and accepted the impact of such decision on customer rates in this and prior proceedings.
On April 2, 2014, the IURC established a subdocket to Duke Energy Indiana’s current fuel adjustment clause proceeding. In this fuel adjustment subdocket, the IURC intends to review underlying causes for net negative generation amounts at the Edwardsport IGCC plant during the period September through November 2013. Duke Energy Indiana contends the net negative generation is related to the consumption of fuel and auxiliary power when the plant was in start-up or off line. In addition to the OUCC, the Duke Energy Indiana Industrial Group, Nucor Steel-Indiana, Steel Dynamics, Inc., and the Joint Intervenors are parties to the subdocket. The IURC has deferred the fuel adjustment subdocket until resolution of the twelfth and thirteenth semi-annual IGCC rider proceedings. In addition, although the IURC approved fuel adjustment clause recovery for the period December 2013 through March 2014, it determined such fuel costs reasonably related to the operational performance of the Edwardsport IGCC plant shall be subject to refund pending the outcome of the twelfth and thirteenth semi-annual IGCC riders.
Duke Energy Indiana cannot predict the outcome of the fuel adjustment clause proceedings or pending and future IGCC Rider proceedings.
FERC Transmission Return on Equity Complaint
On November 12, 2013, customer groups filed with FERC a complaint against MISO and its transmission-owning members, including Duke Energy Indiana, alleging, among other things, that the current base rate of return on equity earned by MISO transmission owners of 12.38 percent is unjust and unreasonable and should be reduced to 9.15 percent. On October 16, 2014, FERC issued an order setting the return on equity issue for settlement and hearing and establishing a refund effective date of November 12, 2013. On November 6, 2014, the MISO transmission owners submitted revisions to the MISO tariff to implement a 0.50 percent adder to the base return on equity based on participation in a RTO. On January 5, 2015, FERC issued an order accepting the adder subject to it being applied to a base return on equity that is shown to be just and reasonable in the pending base return on equity complaint. On January 5, 2015, settlement procedures in the base return on equity proceeding were terminated and a hearing was scheduled for August 17, 2015. On February 12, 2015, certain MISO transmission customers filed with FERC a complaint alleging that the base return on equity should be 8.67 percent and requesting consolidation with the pending base return on equity complaint. Duke Energy Indiana cannot predict the outcome of this matter.
Grid Infrastructure Improvement Plan
On August 29, 2014, Duke Energy Indiana filed a seven-year grid infrastructure improvement plan with the IURC with an estimated cost of $1.9 billion, focusing on the reliability, integrity and modernization of the transmission and distribution system. If approved, 80 percent of the costs will be recovered through a rate rider. The remaining 20 percent are subject to recovery through future rate case proceedings. Hearings were held in January 2015 and Duke Energy Indiana expects a decision in the second quarter of 2015.
Other Regulatory Matters
Atlantic Coast Pipeline
On September 2, 2014, Duke Energy, Dominion Resources (Dominion), Piedmont Natural Gas and AGL Resources announced the formation of a joint venture, Atlantic Coast Pipeline, LLC, to build and own the proposed Atlantic Coast Pipeline (ACP), a 550-mile interstate natural gas pipeline. The ACP is designed to meet the needs identified in requests for proposals by Duke Energy Carolinas, Duke Energy Progress and Piedmont Natural Gas. Dominion will build and operate the ACP and will own 45 percent. Duke Energy will own 40 percent of the pipeline through its Commercial Power segment. The remaining share will be owned by Piedmont Natural Gas and AGL Resources. Duke Energy Carolinas and Duke Energy Progress will be customers of the pipeline and enter into 20-year transportation capacity contracts with ACP, subject to state regulatory approval. In October 2014, the NCUC and PSCSC approved the Duke Energy Carolinas and Duke Energy Progress requests to enter into certain affiliate agreements, pay compensation to ACP and to grant a waiver of certain Code of Conduct provisions relating to contractual and jurisdictional matters. The project will require FERC approval, which the joint venture will seek to secure by summer 2016. The estimated in-service date of the pipeline is late 2018.
East Bend Station
On December 30, 2014, Duke Energy Ohio acquired The Dayton Power and Light Company’s 31 percent interest in East Bend Station for approximately $12.4 million. The purchase price has been reflected in the accompanying financial statements with the net purchase amount as an increase to property, plant and equipment in accordance with FERC guidelines. Duke Energy Ohio expects FERC approval to present the property, plant and equipment and accumulated depreciation at The Dayton Power and Light Company's historical cost.
NC WARN FERC Complaint
On December 16, 2014, NC WARN filed a complaint with the FERC against Duke Energy Carolinas and Duke Energy Progress that alleged Duke Energy Carolinas and Duke Energy Progress manipulated the electricity market by constructing costly and unneeded generation facilities leading to unjust and unreasonable rates; Duke Energy Carolinas and Duke Energy Progress failed to comply with Order 1000 by not effectively connecting their transmission systems with neighboring utilities which also have excess capacity; the plans of Duke Energy Carolinas and Duke Energy Progress for unrealistic future growth leads to unnecessary and expensive generating plants; FERC should investigate the practices of Duke Energy Carolinas and Duke Energy Progress and the potential benefits of having them enter into a regional transmission organization; and FERC should force Duke Energy Carolinas and Duke Energy Progress to purchase power from other utilities rather than construct wasteful and redundant power plants. A copy of the complaint was filed with the PSCSC on January 6, 2015. Duke Energy Carolinas and Duke Energy Progress have filed a responses requesting dismissal of the complaint with the FERC and the PSCSC. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of these proceedings.
Merger Appeals
On January 9, 2013, the City of Orangeburg and NC WARN appealed the NCUC’s approval of the merger between Duke Energy and Progress Energy. On April 29, 2013, the NCUC granted Duke Energy’s motion to dismiss certain exceptions contained in NC WARN’s appeal.
On March 4, 2014, the Court of Appeals issued an opinion affirming the NCUC’s approval of the merger. On April 8, 2014, NC WARN filed a petition for discretionary review by the North Carolina Supreme Court. On April 21, 2014, Duke Energy and the Public Staff jointly filed their response opposing NC WARN’s petition. The City of Orangeburg did not file a petition for discretionary review. On December 19, 2014, the North Carolina Supreme Court denied NC WARN's petition, concluding the appeal.
Progress Energy Merger FERC Mitigation
In June 2012, the FERC approved the merger with Progress Energy, including Duke Energy and Progress Energy’s revised market power mitigation plan, the Joint Dispatch Agreement (JDA) and the joint Open Access Transmission Tariff. Several intervenors filed requests for rehearing challenging various aspects of the FERC approval. On October 29, 2014, FERC denied all of the requests for rehearing.
The revised market power mitigation plan provided for the acceleration of one transmission project and the completion of seven other transmission projects (Long-Term FERC Mitigation) and interim firm power sale agreements during the completion of the transmission projects (Interim FERC Mitigation). The Long-Term FERC Mitigation was expected to increase power imported into the Duke Energy Carolinas and Duke Energy Progress service areas and enhance competitive power supply options in the service areas. All of these projects were completed in or before 2014. On May 30, 2014, the Independent Monitor filed with FERC a final report stating that the Long-Term FERC Mitigation is complete. Therefore, Duke Energy Carolinas' and Duke Energy Progress' obligations associated with the Interim FERC Mitigation have terminated. In the second quarter of 2014, Duke Energy Progress recorded an $18 million partial reversal of an impairment recorded in the third quarter of 2012. This reversal adjusts the initial disallowance from the Long-Term FERC mitigation and reflects updated information on the construction costs and in-service dates of the transmission projects.
Following the closing of the merger, outside counsel reviewed Duke Energy’s mitigation plan and discovered a technical error in the calculations. On December 6, 2013, Duke Energy submitted a filing to the FERC disclosing the error and arguing that no additional mitigation is necessary. The City of New Bern filed a protest and requested that FERC order additional mitigation. On October 29, 2014, FERC ordered that the amount of the stub mitigation be increased from 25 MW to 129 MW. The stub mitigation is Duke Energy’s commitment to set aside for third parties a certain quantity of firm transmission capacity from Duke Energy Carolinas to Duke Energy Progress during summer off-peak hours. FERC also ordered that Duke Energy operate certain phase shifters to create additional import capability and that such operation be monitored by an independent monitor. Duke Energy does not expect the costs to comply with this order to be material. FERC also referred Duke Energy’s failure to expressly designate the phase shifter reactivation as a mitigation project in Duke Energy’s original mitigation plan filing in March 2012 to the FERC Office of Enforcement for further inquiry. Duke Energy cannot predict the outcome of this additional inquiry.
Planned and Potential Coal Plant Retirements
The Subsidiary Registrants periodically file Integrated Resource Plans (IRP) with state regulatory commissions. The IRPs provide a view of forecasted energy needs over a long term (10 to 20 years) and options being considered to meet those needs. Recent IRPs filed by the Subsidiary Registrants included planning assumptions to potentially retire certain coal-fired generating facilities in Florida, Ohio and Indiana earlier than their current estimated useful lives. These facilities do not have the requisite emission control equipment, primarily to meet EPA regulations recently approved or proposed.
The table below contains the net carrying value of generating facilities planned for early retirement or being evaluated for potential retirement included in Net property, plant and equipment on the Consolidated Balance Sheets, excluding the Duke Energy Carolinas 170 MW Lee Unit 3 which is being converted to gas in 2015.
	31-Dec-14
	Duke Energy		Progress Energy(b)		Duke Energy Florida(b)			Duke Energy Ohio(c)		Duke Energy Indiana(d)
Capacity (in MW)	1,704		873		873			163		668
Remaining net book value (in millions)(a)	$	239	$	114	$	114		$	9	$	116
(a)	Included in Net property, plant and equipment as of December 31, 2014, on the Consolidated Balance Sheets.
(b)	Includes Crystal River Units 1 and 2.
(c)	Includes Miami Fort Unit 6 which is expected to be retired by June 1, 2015.
(d)	Includes Wabash River Units 2 through 6. Wabash River Unit 6 is being evaluated for potential conversion to gas. Duke Energy Indiana committed to retire or convert these units by June 2018 in conjunction with a settlement agreement associated with the Edwardsport air permit.
Duke Energy continues to evaluate the potential need to retire these coal-fired generating facilities earlier than the current estimated useful lives, and plans to seek regulatory recovery for amounts that would not be otherwise recovered when any of these assets are retired. However, such recovery, including recovery of carrying costs on remaining book values, could be subject to future regulatory approvals and therefore cannot be assured.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	General Insurance
	The Duke Energy Registrants have insurance and reinsurance coverage either directly or through indemnification from Duke Energy’s captive insurance company, Bison, and its affiliates, consistent with companies engaged in similar commercial operations with similar type properties. The Duke Energy Registrants’ coverage includes (i) commercial general liability coverage for liabilities arising to third parties for bodily injury and property damage; (ii) workers’ compensation; (iii) automobile liability coverage; and (iv) property coverage for all real and personal property damage. Real and personal property damage coverage excludes electric transmission and distribution lines, but includes damages arising from boiler and machinery breakdowns, earthquakes, flood damage and extra expense, but not outage or replacement power coverage. All coverage is subject to certain deductibles or retentions, sublimits, exclusions, terms and conditions common for companies with similar types of operations.
	The Duke Energy Registrants self-insure their electric transmission and distribution lines against loss due to storm damage and other natural disasters. As discussed further in Note 4, Duke Energy Florida maintains a storm damage reserve and has a regulatory mechanism to recover the cost of named storms on an expedited basis.
	The cost of the Duke Energy Registrants’ coverage can fluctuate year to year reflecting claims history and conditions of the insurance and reinsurance markets.
	In the event of a loss, terms and amounts of insurance and reinsurance available might not be adequate to cover claims and other expenses incurred. Uninsured losses and other expenses, to the extent not recovered by other sources, could have a material effect on the Duke Energy Registrants’ results of operations, cash flows or financial position. Each company is responsible to the extent losses may be excluded or exceed limits of the coverage available.
	Nuclear Insurance
	Duke Energy Carolinas owns and operates the McGuire Nuclear Station (McGuire) and the Oconee Nuclear Station (Oconee) and operates and has a partial ownership interest in the Catawba Nuclear Station (Catawba). McGuire and Catawba each have two reactors. Oconee has three reactors. The other joint owners of Catawba reimburse Duke Energy Carolinas for certain expenses associated with nuclear insurance per the Catawba joint owner agreements.
	Duke Energy Progress owns and operates the Robinson Nuclear Station (Robinson) and operates and has a partial ownership interest in the Brunswick and Harris stations. Robinson and Harris each have one reactor. Brunswick has two reactors. The other joint owners of Brunswick and Harris reimburse Duke Energy Progress for certain expenses associated with nuclear insurance per the Brunswick and Harris joint owner agreements.
	Duke Energy Florida manages and has a partial ownership interest in Crystal River Unit 3, which has been retired. The other joint owners of Crystal River Unit 3 reimburse Duke Energy Florida for certain expenses associated with nuclear insurance per the Crystal River Unit 3 joint owner agreement.
	In the event of a loss, terms and amounts of insurance available might not be adequate to cover property damage and other expenses incurred. Uninsured losses and other expenses, to the extent not recovered by other sources, could have a material effect on Duke Energy Carolinas’, Duke Energy Progress’ and Duke Energy Florida’s results of operations, cash flows or financial position. Each company is responsible to the extent losses may be excluded or exceed limits of the coverage available.
	Nuclear Liability Coverage
	The Price-Anderson Act requires owners of nuclear reactors to provide for public nuclear liability protection per nuclear incident up to a maximum total financial protection liability. The maximum total financial protection liability, which is currently $13.6 billion, is subject to change every five years for inflation and the number of licensed reactors. Total nuclear liability coverage consists of a combination of private primary nuclear liability insurance coverage and a mandatory industry risk-sharing program to provide for excess nuclear liability coverage above the maximum reasonably available private primary coverage. The United States Congress could impose revenue-raising measures on the nuclear industry to pay claims.
	Primary Liability Insurance
	Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida have purchased the maximum reasonably available private primary nuclear liability insurance as required by law, which currently is $375 million per station.
	Excess Liability Program
	This program provides $13.2 billion of coverage per incident through the Price-Anderson Act’s mandatory industry-wide excess secondary financial protection program of risk pooling. This amount is the product of potential cumulative retrospective premium assessments of $127 million times the current 104 licensed commercial nuclear reactors in U.S. Under this program, licensees could be assessed retrospective premiums to compensate for public nuclear liability damages in the event of a nuclear incident at any licensed facility in the U.S. Retrospective premiums may be assessed at a rate not to exceed $19 million per year per licensed reactor for each incident. The assessment may be subject to state premium taxes.
	Nuclear Property and Accidental Outage Coverage
	Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida are members of Nuclear Electric Insurance Limited (NEIL), an industry mutual insurance company, which provides "all risk" property damage, decontamination, and premature decommissioning insurance for each station for losses resulting from damage to its nuclear plants, either due to accidents or acts of terrorism. Additionally, NEIL provides some replacement power cost insurance for each station for losses in the event of a major accidental outage at an insured nuclear station. NEIL requires its members to maintain an investment grade credit rating or to ensure collectability of their annual retrospective premium obligation by providing a financial guarantee, letter of credit, deposit premium or other means of assurance. The companies are required each year to report to the NRC the current levels and sources of insurance that demonstrate it possesses sufficient financial resources to stabilize and decontaminate its reactors and reactor station sites in the event of an accident.
	Pursuant to regulations of the NRC, each company’s property damage insurance policies provide that all proceeds from such insurance be applied, first, to place the plant in a safe and stable condition after a qualifying accident, and second, to decontaminate the plant before any proceeds can be used for decommissioning, plant repair or restoration.
	Losses resulting from acts of terrorism are covered as common occurrences, such that if terrorist acts occur against one or more commercial nuclear power plants insured by NEIL within a 12-month period, they would be treated as one event and the owners of the plants where the act occurred would share one full limit of liability. The full limit of liability is currently $3.2 billion. NEIL sublimits the total aggregate for all of their policies for non-nuclear terrorist events to approximately $1.83 billion.
	Each nuclear facility has accident property damage, decontamination and premature decommissioning liability insurance from NEIL with limits of $1.5 billion, except for Crystal River Unit 3. Crystal River Unit 3’s limit is $1.1 billion and is on an actual cash value basis. NEIL coverage for Crystal River 3 does not include property damage to or resulting from the containment structure except coverage does apply to decontamination and debris removal, if required following an accident, to ensure public health and safety or if property damage results from a terrorism event. All nuclear facilities except for Catawba and Crystal River Unit 3 also share an additional $1.25 billion nuclear accident insurance limit above their dedicated underlying limit. This shared additional excess limit is not subject to reinstatement in the event of a loss. Catawba has a dedicated $1.25 billion of additional nuclear accident insurance limit above its dedicated underlying limit. Catawba and Oconee also have an additional $750 million of non-nuclear accident property damage limit.
	NEIL’s Accidental Outage policy provides some replacement power cost insurance for losses in the event of a major accident property damage outage of a nuclear unit. Coverage is provided on a weekly limit basis after a significant waiting period deductible and at 100 percent of the available weekly limits for 52 weeks and 80 percent of the available weekly limits for the next 110 weeks. Coverage is provided until policy aggregate limits are met where the accidental outage policy limit is $490 million for McGuire and Catawba, $381 million for Oconee, $419 million for Brunswick, $384 million for Harris and $329 million for Robinson. NEIL sublimits the accidental outage recovery to the first 104 weeks of coverage not to exceed $328 million from non-nuclear accidental property damage. Coverage amounts decrease in the event more than one unit at a station is out of service due to a common accident.
	Potential Retroactive Premium Assessments
	In the event of NEIL losses, NEIL’s board of directors may assess member companies retroactive premiums of amounts up to 10 times their annual premiums for up to 6 years after a loss. NEIL has never exercised this assessment. The maximum aggregate annual retrospective premium obligations for Duke Energy Carolinas are $73 million for primary property insurance and $32 million for accidental outage insurance. The maximum aggregate annual retrospective premium obligations Duke Energy Progress are $60 million for primary property insurance and $16 million for accidental outage insurance. Duke Energy Carolinas maintains excess property insurance for Catawba with a maximum assessment of $7 million, and shares with Duke Energy Progress blanket excess property limits across other sites with a combined potential maximum assessment of $17 million. The current potential maximum assessments for Duke Energy Florida are $8 million for primary property insurance. The maximum assessment amounts include 100 percent of Duke Energy Carolinas’, Duke Energy Progress’, and Duke Energy Florida’s potential obligations to NEIL for their share of jointly owned reactors.
	ENVIRONMENTAL
	Duke Energy is subject to international, federal, state, and local regulations regarding air and water quality, hazardous and solid waste disposal, and other environmental matters. The Subsidiary Registrants are subject to federal, state, and local regulations regarding air and water quality, hazardous and solid waste disposal and other environmental matters. These regulations can be changed from time to time, imposing new obligations on the Duke Energy Registrants.
	The following environmental matters impact all of the Duke Energy Registrants.
	Remediation Activities
	The Duke Energy Registrants are responsible for environmental remediation at various contaminated sites. These include some properties that are part of ongoing operations and sites formerly owned or used by Duke Energy entities. These sites are in various stages of investigation, remediation and monitoring. Managed in conjunction with relevant federal, state and local agencies, activities vary with site conditions and locations, remediation requirements, complexity and sharing of responsibility. If remediation activities involve joint and several liability provisions, strict liability, or cost recovery or contribution actions, the Duke Energy Registrants could potentially be held responsible for contamination caused by other potentially responsible parties, and may also benefit from insurance policies or contractual indemnities that cover some or all cleanup costs. Liabilities are recorded when losses become probable and are reasonably estimable. The total costs that may be incurred cannot be estimated because the extent of environmental impact, allocation among potentially responsible parties, remediation alternatives, and/or regulatory decisions have not yet been determined. Additional costs associated with remediation activities are likely to be incurred in the future and could be significant. Costs are typically expensed as Operation, maintenance and other in the Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable.
	The following table contains information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheets.
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Balance at December 31, 2011	61			12			23			11		12			28			9
	Provisions / adjustments	39			1			19			5		14			5			3
	Cash reductions	(25	)		(1	)		(9	)		(2	)	(7	)		(18	)		(4	)
	Balance at December 31, 2012	75			12			33			14		19			15			8
	Provisions / adjustments	26			—			4			(1	)	5			20			1
	Cash reductions	(22	)		(1	)		(10	)		(5	)	(5	)		(8	)		(2	)
	Balance at December 31, 2013	79			11			27			8		19			27			7
	Provisions / adjustments	32			(1	)		1			4		(3	)		28			4
	Cash reductions	(14	)		—			(11	)		(7	)	(4	)		(1	)		(1	)
	Balance at December 31, 2014	97			10			17			5		12			54			10
	Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are presented in the table below.
	(in millions)
	Duke Energy	$	89
	Duke Energy Carolinas	25
	Progress Energy	15
	Duke Energy Progress	1
	Duke Energy Florida	14
	Duke Energy Ohio	42
	Duke Energy Indiana	7
	North Carolina and South Carolina Ash Basins
	On February 2, 2014, a break in a 48-inch stormwater pipe beneath an ash basin at Duke Energy Carolinas’ retired Dan River steam station caused a release of ash basin water and ash into the Dan River. On February 8, 2014, a permanent plug was installed in the 48-inch stormwater pipe, stopping the release of materials into the river. Duke Energy Carolinas estimates 30,000 to 39,000 tons of ash and 24 million to 27 million gallons of basin water were released into the river during the incident. Duke Energy Carolinas incurred approximately $24 million of repairs and remediation expense related to this incident during the year ended December 31, 2014. These amounts are recorded in Operations, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income. Duke Energy Carolinas will not seek recovery of these costs from customers. In July, Duke Energy completed remediation work identified by the EPA and continues to cooperate with the EPA's civil enforcement process. See the "Litigation" section below for additional information on litigation, investigations, and enforcement actions related to ash basins. Other costs related to the Dan River release, including pending or future state or federal civil enforcement proceedings, future regulatory directives, natural resources damages, additional pending litigation, future claims or litigation, and long-term environmental impact costs cannot be reasonably estimated at this time.
	On September 20, 2014, the North Carolina Coal Ash Management Act of 2014 (Coal Ash Act) became law. The Coal Ash Act (i) establishes a Coal Ash Management Commission to oversee handling of coal ash within the state; (ii) prohibits construction of new and expansion of existing ash impoundments and use of existing impoundments at retired facilities, effective October 1, 2014; (iii) requires closure of ash impoundments at Duke Energy Progress' Asheville and Sutton stations and Duke Energy Carolinas' Riverbend and Dan River stations no later than August 1, 2019; (iv) requires dry disposal of fly ash at active plants not retired by December 31, 2018; (v) requires dry disposal of bottom ash at active plants by December 31, 2019, or retirement of active plants; (vi) requires all remaining ash impoundments in North Carolina to be categorized as high-risk, intermediate-risk, or low-risk no later than December 31, 2015 by the North Carolina Department of Environment and Natural Resources (DENR) with the method of closure and timing to be based upon the assigned risk, with closure no later than December 31, 2029; (vii) establishes requirements to deal with groundwater and surface water impacts from impoundments and (viii) enhances the level of regulation for structural fills utilizing coal ash. The Coal Ash Act includes a variance procedure for compliance deadlines and modification of requirements regarding structural fills and compliance boundaries. Provisions of the Coal Ash Act prohibit cost recovery for unlawful discharge of ash basin waters occurring after January 1, 2014. The Coal Ash Act included a moratorium for any NCUC ordered rate changes to effectuate the legislation, which ended January 15, 2015. The Coal Ash Act leaves the decision on cost recovery determinations related to closure of coal combustion residuals surface impoundments (ash basins or impoundments) to the normal ratemaking processes before utility regulatory commissions. In November 2014, Duke Energy submitted to DENR site specific coal ash excavation plans for the four high priority stations required to be closed no later than August 1, 2019. These plans and all associated permits must be approved by DENR before any excavation work can begin.
	In September 2014, Duke Energy Carolinas executed a consent agreement with the South Carolina Department of Health and Environmental Control (SCDHEC) requiring the excavation of an inactive ash basin and ash fill area at the W.S. Lee Steam Station. As part of this agreement, in December 2014, Duke Energy Carolinas filed an ash removal plan and schedule with SCDHEC.
	Duke Energy Carolinas and Duke Energy Progress recorded asset retirement obligations at December 31, 2014 based upon the legal obligation for closure of coal ash basins and the disposal of related ash as a result of the Coal Ash Act and the agreement with SCDHEC. Refer to Note 9 for further discussion of the asset retirement obligations recorded at December 31, 2014.
	Coal Combustion Residuals
	On December 19, 2014, the EPA signed the first federal regulation for the disposal of coal combustion residuals (CCR) from power plants. The federal regulation classifies CCR as nonhazardous waste under the Resource Conservation and Recovery Act and applies to all new and existing landfills, new and existing surface impoundments, structural fills and CCR piles. The rule establishes requirements regarding landfill design, structural integrity design and assessment criteria for surface impoundments, groundwater monitoring and protection procedures and other operational and reporting procedures to ensure the safe disposal and management of CCR. In addition to the requirements of the federal CCR regulation, CCR landfills and surface impoundments will continue to be independently regulated by most states. Duke Energy records an asset retirement obligation when it has a legal obligation to incur retirement costs associated with the retirement of a long-lived asset and the obligation can be reasonably estimated. Once the rule is effective in 2015, additional asset retirement obligation amounts will be recorded at the Duke registrants. Cost recovery for future expenditures will be pursued through the normal ratemaking process with state utility commissions, which permit recovery of necessary and prudently incurred costs associated with Duke Energy’s regulated operations. At this time, Duke Energy is evaluating the CCR regulation and developing cost estimates that will largely be dependent upon compliance alternatives selected to meet requirements of the regulations. For further discussion of asset retirement obligations see Note 9.
	Litigation
	Duke Energy
	Ash Basin Shareholder Derivative Litigation
	Five shareholder derivative lawsuits have been filed in Delaware Chancery Court relating to the release at Dan River and to the management of Duke Energy’s ash basins. On October 31, 2014, the five lawsuits were consolidated in a single proceeding titled "In Re Duke Energy Corporation Coal Ash Derivative Litigation." On December 2, 2014, plaintiffs filed a Corrected Verified Consolidated Shareholder Derivative Complaint (Consolidated Complaint).
	The Consolidated Complaint names as defendants several current and former Duke Energy officers and directors (collectively, the “Duke Energy Defendants”). Duke Energy is named as a nominal defendant.
	The Consolidated Complaint alleges the Duke Energy Defendants breached their fiduciary duties to the company by failing to adequately oversee Duke Energy’s ash basins and that these breaches of fiduciary duty may have contributed to the incident at Dan River and continued thereafter. The lawsuit also asserts claims against the Duke Energy Defendants for corporate waste (relating to the money Duke Energy has spent and will spend as a result of the fines, penalties, and coal ash removal) and unjust enrichment (relating to the compensation and director remuneration that was received despite these alleged breaches of fiduciary duty). The lawsuit seeks both injunctive relief against Duke Energy and restitution from the Duke Energy Defendants. On January 21, 2015, the Duke Energy Defendants filed a Motion to Stay and an alternative Motion to Dismiss.
On May 28, 2014, Duke Energy received a shareholder litigation demand letter sent on behalf of shareholder Mitchell Pinsly. The letter alleges that the members of the Board of Directors and certain officers breached their fiduciary duties by allowing the company to illegally dispose of and store coal ash pollutants. The letter demands that the Board of Directors take action to recover damages associated with those breaches of fiduciary duty; otherwise, the attorney will file a shareholder derivative action. By letter dated July 3, 2014, counsel for the shareholder was informed that the Board of Directors appointed a Demand Review Committee to evaluate the allegations in the Demand Letter.
It is not possible to predict whether Duke Energy will incur any liability or to estimate the damages, if any, it might incur in connection with these matters.
Progress Energy Merger Shareholder Litigation
Duke Energy, the eleven members of the Board of Directors who were also members of the pre-merger Board of Directors (Legacy Duke Energy Directors) and certain Duke Energy officers are defendants in a purported securities class action lawsuit (Nieman v. Duke Energy Corporation, et al). This lawsuit consolidates three lawsuits originally filed in July 2012, and is pending in the United States District Court for the Western District of North Carolina. The plaintiffs allege federal Securities Act and Exchange Act claims based on allegations of materially false and misleading representations and omissions in the Registration Statement filed on July 7, 2011, and purportedly incorporated into other documents, all in connection with the post-merger change in Chief Executive Officer (CEO). On August 15, 2014, the parties reached an agreement in principle to settle the litigation for an amount which, net of the expected proceeds of insurance policies, is not anticipated to have a material effect on the results of operations, cash flows or financial position of Duke Energy. On December 2, 2014, the parties executed a Memorandum of Understanding relating to the settlement which will be submitted to the court for approval.
On May 31, 2013, the Delaware Chancery Court consolidated four shareholder derivative lawsuits filed in 2012. The Court also appointed a lead plaintiff and counsel for plaintiffs and designated the case as In Re Duke Energy Corporation Derivative Litigation. The lawsuit names as defendants the Legacy Duke Energy Directors. Duke Energy is named as a nominal defendant. The case alleges claims for breach of fiduciary duties of loyalty and care in connection with the post-merger change in CEO. The case is stayed pending resolution of the Nieman v. Duke Energy Corporation, et al. case in North Carolina.
Two shareholder Derivative Complaints, filed in 2012 in federal district court in Delaware, were consolidated as Tansey v. Rogers, et al. The case alleges claims for breach of fiduciary duty and waste of corporate assets, as well as claims under Section 14(a) and 20(a) of the Exchange Act. Duke Energy is named as a nominal defendant. Pursuant to an Order entered on September 2, 2014, the court administratively closed this consolidated derivative action. The parties filed a status report with the court on December 1, 2014, and will continue to do so every six months thereafter until the Nieman v. Duke Energy Corporation, et al. case in North Carolina has been resolved.
On August 3, 2012, Duke Energy was served with a shareholder Derivative Complaint, which was transferred to the North Carolina Business Court (Krieger v. Johnson, et al.). The lawsuit names as defendants William D. Johnson and the Legacy Duke Energy Directors. Duke Energy is named as a nominal defendant. The lawsuit alleges claims for breach of fiduciary duty in granting excessive compensation to Mr. Johnson. On April 30, 2014, the North Carolina Business Court granted the Legacy Duke Energy Directors’ motion to dismiss the lawsuit.
It is not possible to estimate the maximum exposure of loss that may occur in connection with these lawsuits.
Price Reporting Cases
A total of five lawsuits were filed against Duke Energy affiliates and other energy companies and remain pending in a consolidated, single federal court proceeding in Nevada. Each of these lawsuits contain similar claims that defendants allegedly manipulated natural gas markets by various means, including providing false information to natural gas trade publications and entering into unlawful arrangements and agreements in violation of the antitrust laws of the respective states. Plaintiffs seek damages in unspecified amounts.
On July 18, 2011, the judge granted a defendant’s motion for summary judgment in two of the remaining five cases to which Duke Energy affiliates are a party. The U.S. Court of Appeals for the Ninth Circuit subsequently reversed the lower court’s decision. On July 1, 2014, the U.S. Supreme Court granted the defendants', including Duke Energy, petition for certiorari. Oral argument was held on January 12, 2015.
It is not possible to predict whether Duke Energy will incur any liability or to estimate the damages, if any, it might incur in connection with the remaining matters. However, based on Duke Energy’s past experiences with similar cases of this nature, it does not believe its exposure under these remaining matters is material.
Brazil Expansion Lawsuit
On August 9, 2011, the State of São Paulo sued Duke Energy International Geracao Paranapenema S.A. (DEIGP) in Brazilian state court. The lawsuit claims DEIGP is under a continuing obligation to expand installed generation capacity in the State of São Paulo by 15 percent pursuant to a stock purchase agreement under which DEIGP purchased generation assets from the state. On August 10, 2011, a judge granted an ex parte injunction ordering DEIGP to present a detailed expansion plan in satisfaction of the 15 percent obligation. DEIGP has previously taken a position the expansion obligation is no longer viable given changes that have occurred in the electric energy sector since privatization. DEIGP submitted its proposed expansion plan on November 11, 2011, but reserved objections regarding enforceability. It is not possible to predict whether Duke Energy will incur any liability or to estimate the damages, if any, it might incur in connection with this matter.
Duke Energy Carolinas and Duke Energy Progress
DENR State Enforcement Actions
In the first quarter of 2013, environmental organizations sent notices of intent to sue Duke Energy Carolinas and Duke Energy Progress related to alleged groundwater violations and Clean Water Act (CWA) violations from coal ash basins at two of their coal-fired power plants in North Carolina. DENR filed enforcement actions against Duke Energy Carolinas and Duke Energy Progress alleging violations of water discharge permits and North Carolina groundwater standards. The case against Duke Energy Carolinas was filed in Mecklenburg County Superior Court. The case against Duke Energy Progress was filed in Wake County Superior Court. The cases are being heard before a single judge.
On October 4, 2013, Duke Energy Carolinas, Duke Energy Progress and DENR negotiated a proposed consent order covering these two plants. The consent order would have assessed civil penalties and imposed a compliance schedule requiring Duke Energy Carolinas and Duke Energy Progress to undertake monitoring and data collection activities toward making appropriate corrective action to address any substantiated violations. In light of the coal ash release that occurred at Dan River on February 2, 2014, on March 21, 2014, DENR withdrew its support of the consent orders and requested that the court proceed with the litigation.
On August 16, 2013, DENR filed an enforcement action against Duke Energy Carolinas and Duke Energy Progress related to their remaining plants in North Carolina, alleging violations of the CWA and violations of the North Carolina groundwater standards. The case against Duke Energy Carolinas was filed in Mecklenburg County Superior Court. The case against Duke Energy Progress was filed in Wake County Superior Court. Both of these cases have been assigned to the judge handling the enforcement actions discussed above. Southern Environmental Law Center (SELC), on behalf of several environmental groups, has been permitted to intervene in these cases.
It is not possible to predict any liability or estimate any damages Duke Energy Carolinas or Duke Energy Progress might incur in connection with these matters.
North Carolina Declaratory Judgment Action
On October 10, 2012, the SELC, on behalf of the same environmental groups that were permitted to challenge the consent decrees discussed above, filed a petition with the North Carolina Environmental Management Commission (EMC) asking for a declaratory ruling seeking to clarify the application of the state’s groundwater protection rules to coal ash basins. The petition sought to change the interpretation of regulations that permitted DENR to assess the extent, cause and significance of any groundwater contamination before ordering action to eliminate the source of contamination, among other issues. Duke Energy Carolinas and Duke Energy Progress were both permitted to intervene in the matter. On December 3, 2012, the EMC affirmed this interpretation of the regulations.
On March 6, 2014, the North Carolina State Court judge overturned the ruling of the EMC holding that in the case of groundwater contamination, DENR was required to issue an order to immediately eliminate the source of the contamination before an assessment of the nature, significance and extent of the contamination or the continuing damage to the groundwater was conducted. Duke Energy Carolinas, Duke Energy Progress, and the EMC appealed the ruling in April 2014. On May 16, 2014, the North Carolina Court of Appeals denied a petition to stay the case during the appeal. On October 10, 2014, the parties were notified the case has been transferred to the NCSC. Oral argument has been scheduled for March 16, 2015.
Federal Citizens Suits
There are currently five cases filed in various North Carolina federal courts contending that the DENR state enforcement actions discussed above do not adequately address the issues raised in the notices of intent to sue related to the Riverbend, Sutton, Cape Fear, H.F. Lee and Buck plants.
On June 11, 2013, Catawba Riverkeeper Foundation, Inc. (Catawba Riverkeeper) filed a separate action in the United States Court for the Western District of North Carolina. The lawsuit contends the state enforcement action discussed above does not adequately address issues raised in Catawba Riverkeeper’s notice of intent to sue relating to the Riverbend plant. On April 11, 2014, the Court denied Catawba Riverkeeper’s objections to the Magistrate Judge’s recommendation that plaintiff’s case be dismissed as well as Duke Energy Carolinas’ motion to dismiss. The Court allowed limited discovery, after which Duke Energy Carolinas may file any renewed motions to dismiss.
On September 12, 2013, Cape Fear River Watch, Inc., Sierra Club, and Waterkeeper Alliance filed a citizen suit in the Federal District Court for the Eastern District of North Carolina. The lawsuit alleges unpermitted discharges to surface water and groundwater violations at the Sutton plant. On June 9, 2014, the court granted Duke Energy Progress' request to dismiss the groundwater claims but rejected its request to dismiss the surface water claims. In response to a motion filed by the SELC, on August 1, 2014, the court modified the original June 9th order to dismiss only the plaintiff's federal law claim based on hydrologic connections at Sutton Lake. The claims related to the alleged state court violations of the permits are back in the case.
On September 3, 2014, three cases were filed by various environmental groups: (i) a citizen suit in the United States Court for the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Cape Fear plant; (ii) a citizen suit in the United States Court for the Eastern District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the H.F. Lee plant; and (iii) a citizen suit in the United States Court for the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Buck plant. On January 5, 2015, Duke Energy Carolinas filed a Motion to Dismiss and a Motion to Stay the proceeding relating to the Buck plant.
It is not possible to predict whether Duke Energy Carolinas or Duke Energy Progress will incur any liability or to estimate the damages, if any, they might incur in connection with these matters.
North Carolina Ash Basin Grand Jury Investigation
As a result of the Dan River ash basin water release discussed above, DENR issued a Notice of Violation and Recommendation of Assessment of Civil Penalties with respect to this matter on February 28, 2014, which the company responded to on March 13, 2014. Duke Energy and certain Duke Energy employees received subpoenas issued by the United States Attorney for the Eastern District of North Carolina in connection with a criminal investigation related to the release and all 14 of the North Carolina facilities with ash basins and the nature of Duke Energy's contacts with DENR with respect to those facilities. This is a multidistrict investigation that also involves state law enforcement authorities.
On February 20, 2015, Duke Energy Carolinas, Duke Energy Progress and Duke Energy Business Services LLC (DEBS), a wholly owned subsidiary of Duke Energy, each entered into a Memorandum of Plea Agreement (Plea Agreements) in connection with the investigation initiated by the United States Department of Justice Environmental Crimes Section and the United States Attorneys for the Eastern District of North Carolina, the Middle District of North Carolina and the Western District of North Carolina (collectively, USDOJ). The Plea Agreements are subject to the approval of the United States District Court for the Eastern District of North Carolina and, if approved, will end the grand jury investigation related to the Dan River ash basin release and the management of coal ash basins at 14 plants in North Carolina with coal ash basins, as discussed above.
Under the Plea Agreements, the USDOJ charged DEBS and Duke Energy Progress with four misdemeanor CWA violations related to violations at Duke Energy Progress’ H.F. Lee Steam Electric Plant, Cape Fear Steam Electric Plant and Asheville Steam Electric Generating Plant. The USDOJ charged Duke Energy Carolinas and DEBS with five misdemeanor CWA violations related to violations at Duke Energy Carolinas’ Dan River Steam Station and Riverbend Steam Station. DEBS, Duke Energy Carolinas and Duke Energy Progress also agreed (i) to a five-year probation period, (ii) to pay a total of approximately $68 million in fines and restitution and $34 million for community service and mitigation (the Payments), and (iii) to establish environmental compliance plans subject to the oversight of a court-appointed monitor paid for by the companies for the duration of the probation period (iii) for Duke Energy Carolinas and Duke Energy Progress each to maintain $250 million under their Master Credit Facility as security to meet their obligations under the Pleas Agreements, in addition to certain other conditions set out in the Plea Agreements. Payments under the Plea Agreements will be borne by shareholders and are not tax deductible. Duke Energy Corporation has agreed to issue a guarantee of all payments and performance due from the Companies, including but not limited to payments for fines, restitution, community service, mitigation and the funding of, and obligations under, the environmental compliance plans. As a result of the Plea Agreements, Duke Energy Carolinas and Duke Energy Progress recognized charges of $72 million and $30 million, respectively, in the fourth quarter of 2014. The amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
The Plea Agreements do not cover pending civil claims related to the Dan River coal ash release and operations at other North Carolina coal plants. Duke Energy Corporation will continue to cooperate with government agencies and defend against remaining civil litigation associated with these matters.
Duke Energy Carolinas
New Source Review
In 1999-2000, the U.S. Department of Justice on behalf of the EPA filed a number of complaints and notices of violation against multiple utilities, including Duke Energy Carolinas, for alleged violations of the New Source Review (NSR) provisions of the Clean Air Act (CAA). The government alleges the utilities violated the CAA when undertaking certain maintenance and repair projects at certain coal plants without (i) obtaining NSR permits and (ii) installing the best available emission controls for sulfur dioxide, nitrogen oxide and particulate matter. The complaints seek the installation of pollution control technology on generating units that allegedly violated the CAA, and unspecified civil penalties in amounts of up to $37,500 per day for each violation. Duke Energy Carolinas asserts there were no CAA violations because the applicable regulations do not require NSR permitting in cases where the projects undertaken are “routine” or otherwise do not result in a net increase in emissions.
In 2000, the government sued Duke Energy Carolinas in the U.S. District Court in Greensboro, North Carolina, claiming NSR violations for 29 projects performed at 25 of Duke Energy Carolinas’ coal-fired units. Duke Energy Carolinas asserts the projects were routine and not projected to increase emissions. The parties subsequently filed a stipulation agreeing to dismiss with prejudice all but 13 claims at 13 generating units, 11 of which have since been retired. The parties filed opposing motions for summary judgment on the remaining claims. The Court substantially denied both motions for summary judgment. A Duke Energy request for leave to file another motion for summary judgment on alternative grounds, including expiration of the applicable statute of limitations, was denied. On October 24, 2014, Duke Energy Carolinas filed a motion to certify an appeal of the statute of limitations issue to the U.S. Court of Appeals for the Fourth Circuit. That motion is pending. Trial date has been set for October 2015. It is not possible to predict whether Duke Energy Carolinas will incur any liability or to estimate the damages, if any, it might incur in connection with this matter. Ultimate resolution of these matters could have a material effect on the results of operations, cash flows or financial position of Duke Energy Carolinas. However, the appropriate regulatory recovery will be pursued for costs incurred in connection with such resolution.
Asbestos-related Injuries and Damages Claims
Duke Energy Carolinas has experienced numerous claims for indemnification and medical cost reimbursement related to asbestos exposure. These claims relate to damages for bodily injuries alleged to have arisen from exposure to or use of asbestos in connection with construction and maintenance activities conducted on its electric generation plants prior to 1985. As of December 31, 2014, there were 54 asserted claims for non-malignant cases with the cumulative relief sought of up to $11 million, and 28 asserted claims for malignant cases with the cumulative relief sought of up to $7 million. Based on Duke Energy Carolinas’ experience, it is expected that the ultimate resolution of most of these claims likely will be less than the amount claimed.
Duke Energy Carolinas has recognized asbestos-related reserves of $575 million at December 31, 2014 and $616 million at December 31, 2013. These reserves are classified in Other within Deferred Credits and Other Liabilities and Other within Current Liabilities on the Consolidated Balance Sheets. These reserves are based upon the minimum amount of the range of loss for current and future asbestos claims through 2033, are recorded on an undiscounted basis and incorporate anticipated inflation. In light of the uncertainties inherent in a longer-term forecast, management does not believe they can reasonably estimate the indemnity and medical costs that might be incurred after 2033 related to such potential claims. It is possible Duke Energy Carolinas may incur asbestos liabilities in excess of the recorded reserves.
Duke Energy Carolinas has third-party insurance to cover certain losses related to asbestos-related injuries and damages above an aggregate self-insured retention of $476 million. Duke Energy Carolinas’ cumulative payments began to exceed the self-insurance retention in 2008. Future payments up to the policy limit will be reimbursed by the third-party insurance carrier. The insurance policy limit for potential future insurance recoveries for indemnification and medical cost claim payments is $864 million in excess of the self-insured retention. Receivables for insurance recoveries were $616 million at December 31, 2014 and $649 million at December 31, 2013. These amounts are classified in Other within Investments and Other Assets and Receivables on the Consolidated Balance Sheets. Duke Energy Carolinas is not aware of any uncertainties regarding the legal sufficiency of insurance claims. Duke Energy Carolinas believes the insurance recovery asset is probable of recovery as the insurance carrier continues to have a strong financial strength rating.
Progress Energy
Synthetic Fuels Matters
Progress Energy and a number of its subsidiaries and affiliates are defendants in lawsuits arising out of a 1999 Asset Purchase Agreement. Parties to the Asset Purchase Agreement include U.S. Global, LLC (Global) and affiliates of Progress Energy.
In a case filed in the Circuit Court for Broward County, Florida, in March 2003 (the Florida Global Case), Global requested an unspecified amount of compensatory damages, as well as declaratory relief. In November 2009, the court ruled in favor of Global. In December 2009, Progress Energy made a $154 million payment which represented payment of the total judgment, including prejudgment interest, and a required premium equivalent to two years of interest, to the Broward County Clerk of Court bond account. Progress Energy continued to accrue interest related to this judgment.
On October 3, 2012, the Florida Fourth District Court of Appeals reversed the lower court ruling. The court held that Global was entitled to approximately $90 million of the amount paid into the registry of the court. Progress Energy was entitled to a refund of the remainder of the funds. Progress Energy received cash and recorded a $63 million pretax gain for the refund in December 2012. The gain was recorded in Income from Discontinued Operations, net of tax in the Consolidated Statements of Operations and Comprehensive Income.
On May 9, 2013, Global filed a Seventh Amended Complaint asserting a single count for breach of the Asset Purchase Agreement and seeking specific performance. The parties reached a settlement in this matter in May 2014, and the case has been dismissed. The amount of the settlement did not have a material effect on the results of operations, cash flows or financial position of Progress Energy. As a result of the settlement of the Florida Global Case, a second suit filed in the Superior Court for Wake County, North Carolina, Progress Synfuel Holdings, Inc. et al. v. U.S. Global, LLC, has been dismissed.
Duke Energy Progress and Duke Energy Florida
Spent Nuclear Fuel Matters
On December 12, 2011, Duke Energy Progress and Duke Energy Florida sued the United States in the U.S. Court of Federal Claims. The lawsuit claimed the Department of Energy breached a contract in failing to accept spent nuclear fuel under the Nuclear Waste Policy Act of 1982 and asserted damages for the cost of on-site storage. Duke Energy Progress and Duke Energy Florida asserted damages for the period January 1, 2006 through December 31, 2010. Claims for all periods prior to 2006 have been resolved. On March 24, 2014, the U.S. Court of Federal Claims issued a judgment in favor of Duke Energy Progress and Duke Energy Florida on this matter, awarding amounts of $83 million and $21 million, respectively. The majority of the awards were recorded as a reduction to capital costs associated with construction of on-site storage facilities. Duke Energy Progress and Duke Energy Florida received payment of the award in September 2014. On October 16, 2014, Duke Energy Progress and Duke Energy Florida filed a new action for costs incurred from 2011 through 2013.
Duke Energy Florida
Westinghouse Contract Litigation
On March 28, 2014 Duke Energy Florida filed a lawsuit against Westinghouse in the U.S. District Court for the Western District of North Carolina. The lawsuit seeks recovery of $54 million in milestone payments in excess of work performed under the terminated EPC for Levy as well as a determination by the court of the amounts due to Westinghouse as a result of the termination of the EPC.
On March 31, 2014, Westinghouse filed a lawsuit against Duke Energy Florida in U.S. District Court for the Western District of Pennsylvania. The Pennsylvania lawsuit alleged damages under the EPC in excess of $510 million for engineering and design work, costs to end supplier contracts and an alleged termination fee.
On June 9, 2014, the judge in the North Carolina case ruled that the litigation will proceed in the Western District of North Carolina. In November 2014, Westinghouse filed a Motion for Partial Judgment on the pleadings which was denied by the Magistrate Judge on February 20, 2015, subject to court approval. Trial is set for February 2016. It is not possible to predict the outcome of the litigation and whether Duke Energy Florida will incur any liability for terminating the EPC or to estimate the damages, if any, it might incur in connection with these matters. Ultimate resolution of these matters could have a material effect on the results of operations, financial position or cash flows of Duke Energy Florida. However, appropriate regulatory recovery will be pursued for the retail portion of any costs incurred in connection with such resolution.
Duke Energy Ohio
Antitrust Lawsuit
In January 2008, four plaintiffs, including individual, industrial and nonprofit customers, filed a lawsuit against Duke Energy Ohio in federal court in the Southern District of Ohio. Plaintiffs alleged Duke Energy Ohio conspired to provide inequitable and unfair price advantages for certain large business consumers by entering into non-public option agreements in exchange for their withdrawal of challenges to Duke Energy Ohio’s Rate Stabilization Plan implemented in early 2005. In March 2014, a federal judge certified this matter as a class action. The parties have agreed to mediation on March 31, 2015. Trial has been set to begin on July 27, 2015. It is not possible to predict whether Duke Energy Ohio will incur any liability or to estimate the damages, if any, that may be incurred in connection with this matter. Ultimate resolution of this matter could have a material effect on the results of operations, cash flows or financial position of Duke Energy Ohio.
Any liability related to the lawsuit attributable to the Disposal Group will not be transferred to Dynegy upon closing of the disposal of the Midwest generation business.
Asbestos-related Injuries and Damages Claims
Duke Energy Ohio has been named as a defendant or co-defendant in lawsuits related to asbestos exposure at its electric generating stations. The impact on Duke Energy Ohio’s results of operations, cash flows or financial position of these cases to date has not been material. Based on estimates under varying assumptions concerning uncertainties, such as, among others: (i) the number of contractors potentially exposed to asbestos during construction or maintenance of Duke Energy Ohio generating plants, (ii) the possible incidence of various illnesses among exposed workers, and (iii) the potential settlement costs without federal or other legislation that addresses asbestos tort actions, Duke Energy Ohio estimates that the range of reasonably possible exposure in existing and future suits over the foreseeable future is not material. This assessment may change as additional settlements occur, claims are made, and more case law is established.
Duke Energy Indiana
Edwardsport IGCC
On December 11, 2012, Duke Energy Indiana filed an arbitration action against General Electric Company and Bechtel Corporation in connection with their work at the Edwardsport IGCC facility. Duke Energy Indiana is seeking damages equaling some or all of the additional costs incurred in the construction of the project not recovered at the IURC. The arbitration hearing concluded December 15, 2014. The parties will submit post hearing briefs. Duke Energy Indiana cannot predict the outcome of this matter.
Other Litigation and Legal Proceedings
The Duke Energy Registrants are involved in other legal, tax and regulatory proceedings arising in the ordinary course of business, some of which involve significant amounts. The Duke Energy Registrants believe the final disposition of these proceedings will not have a material effect on their results of operations, cash flows or financial position.
The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters discussed above, excluding asbestos related reserves. Reserves are classified on the Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Accounts payable and Other within Current Liabilities. The reasonably possible range of loss for all non-asbestos related matters in excess of recorded reserves is not material.
	December 31,
(in millions)	2014				2013
Reserves for Legal Matters
Duke Energy	$	323			$	204
Duke Energy Carolinas	72				—
Progress Energy	93				78
Duke Energy Progress	37				10
Duke Energy Florida	36				43
OTHER COMMITMENTS AND CONTINGENCIES
General
As part of their normal business, the Duke Energy Registrants are party to various financial guarantees, performance guarantees, and other contractual commitments to extend guarantees of credit and other assistance to various subsidiaries, investees, and other third parties. These guarantees involve elements of performance and credit risk, which are not fully recognized on the Consolidated Balance Sheets and have unlimited maximum potential payments. However, the Duke Energy Registrants do not believe these guarantees will have a material effect on their results of operations, cash flows or financial position.
Purchase Obligations
Purchased Power
Duke Energy Progress and Duke Energy Florida have ongoing purchased power contracts, including renewable energy contracts, with other utilities, wholesale marketers, co-generators, and qualified facilities. These purchased power contracts generally provide for capacity and energy payments. In addition, Duke Energy Progress and Duke Energy Florida have various contracts to secure transmission rights.
The following table presents executory purchased power contracts, excluding contracts classified as leases. All contracts represent 100 percent of net plant output.
			Minimum Purchase Amount at December 31, 2014
(in millions)	Contract Expiration		2015				2016			2017			2018				2019				Thereafter			Total
Duke Energy Progress	2019-2022		$	59			60			$	61		$	62			$	63			$	93		$	398
Duke Energy Florida	2023-2043		244				273			291			306				322				1,907			3,343
Operating and Capital Lease Commitments
The Duke Energy Registrants lease office buildings, railcars, vehicles, computer equipment and other property and equipment with various terms and expiration dates. Additionally, Duke Energy Progress has a capital lease related to firm gas pipeline transportation capacity. Duke Energy Progress and Duke Energy Florida have entered into certain purchased power agreements, which are classified as leases. Consolidated capitalized lease obligations are classified as Long-Term Debt or Other within Current Liabilities on the Consolidated Balance Sheets. Amortization of assets recorded under capital leases is included in Depreciation and amortization and Fuel used in electric generation – regulated on the Consolidated Statements of Operations.
The following table presents rental expense for operating leases. These amounts are included in Operation, maintenance and other on the Consolidated Statements of Operations.
	Years Ended December 31,
(in millions)	2014				2013				2012
Duke Energy	$	355			$	321			$	232
Duke Energy Carolinas	41				39				38
Progress Energy	257				225				232
Duke Energy Progress	161				153				164
Duke Energy Florida	96				72				68
Duke Energy Ohio	17				14				14
Duke Energy Indiana	21				22				20
The following table presents future minimum lease payments under operating leases, which at inception had a non-cancelable term of more than one year.
	December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
2015	$	205			$	33			$	129		$	65			$	64			$	12		$	17
2016	198				29				130			66				64				11			15
2017	172				26				111			65				46				9			13
2018	157				20				109			64				45				7			10
2019	148				17				103			58				45				6			9
Thereafter	938				64				709			421				288				18			9
Total	$	1,818			$	189			$	1,291		$	739			$	552			$	63		$	73
The following table presents future minimum lease payments under capital leases.
	December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
2015	$	178			$	6			$	46		$	21			$	26			$	7		$	4
2016	188				6				47			21				26				7			4
2017	190				7				47			21				26				3			2
2018	198				7				48			22				26				4			2
2019	208				8				51			25				26				2			2
Thereafter	1,771				60				678			398				280				—			42
Minimum annual payments	2,733				94				917			508				410				23			56
Less: amount representing interest	(1,305		)		(67		)		(603		)	(361		)		(242		)		(3		)	(39		)
Total	$	1,428			$	27			$	314		$	147			$	168			$	20		$	17

Debt_and_Credit_Facilities

Debt and Credit Facilities	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Debt and Credit Facilities	DEBT AND CREDIT FACILITIES
	Summary of Debt and Related Terms
	The following tables summarize outstanding debt.
		December 31, 2014
	(in millions)	Weighted Average Interest Rate			Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Unsecured debt, maturing 2015 - 2073	4.92	%		$	12,937		$	1,155		$	3,850		$	—		$	150		$	773		$	742
	Secured debt, maturing 2016 - 2037	2.5	%		2,806			400			525			300			225			—			—
	First mortgage bonds, maturing 2015 - 2044(a)	4.76	%		19,180			6,161			9,800			5,475			4,325			900			2,319
	Capital leases, maturing 2015 - 2051(b)	5.3	%		1,428			27			314			146			168			20			16
	Tax-exempt bonds, maturing 2015 - 2041(c)	2.13	%		1,296			355			291			291			—			77			573
	Notes payable and commercial paper(d)	0.7	%		2,989			—			—			—			—			—			—
	Money pool/intercompany borrowings				—			300			835			—			84			516			221
	Fair value hedge carrying value adjustment				8			8			—			—			—			—			—
	Unamortized debt discount and premium, net(e)				1,890			(15		)	(26		)	(11		)	(8		)	(29		)	(9		)
	Total debt	4.29	%		$	42,534		$	8,391		$	15,589		$	6,201		$	4,944		$	2,257		$	3,862
	Short-term notes payable and commercial paper				(2,514		)	—			—			—			—			—			—
	Short-term money pool borrowings				—			—			(835		)	—			(84		)	(491		)	(71		)
	Current maturities of long-term debt(f)				(2,807		)	(507		)	(1,507		)	(945		)	(562		)	(157		)	(5		)
	Total long-term debt(f)	4.58	%		$	37,213		$	7,884		$	13,247		$	5,256		$	4,298		$	1,609		$	3,786
	(a)    Substantially all electric utility property is mortgaged under mortgage bond indentures.
	(b)	Duke Energy includes $129 million and $787 million of capital lease purchase accounting adjustments related to Duke Energy Progress and Duke Energy Florida, respectively, related to power purchase agreements that are not accounted for as capital leases in their respective financial statements because of grandfathering provisions in GAAP.
	(c)	Substantially all tax-exempt bonds are secured by first mortgage bonds or letters of credit.
	(d)	Includes $475 million that was classified as Long-Term Debt on the Consolidated Balance Sheets due to the existence of long-term credit facilities that back-stop these commercial paper balances, along with Duke Energy’s ability and intent to refinance these balances on a long-term basis. The weighted-average days to maturity was 27 days.
	(e)	Duke Energy includes $1,975 million in purchase accounting adjustments related to the merger with Progress Energy. See Note 2 for additional information.
	(f)	Refer to Note 17 for additional information on amounts from consolidated VIE’s.
		December 31, 2013
	(in millions)	Weighted Average Interest Rate			Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Unsecured debt, maturing 2014 - 2073	5.18	%		$	13,550		$	1,157		$	4,150		$	—		$	150		$	805		$	744
	Secured debt, maturing 2014 - 2037	2.69	%		2,559			400			305			305			—			—			—
	First mortgage bonds, maturing 2015 - 2043(a)	4.9	%		17,831			6,161			8,450			4,125			4,325			900			2,319
	Capital leases, maturing 2014 - 2051(b)	5.23	%		1,516			30			327			148			179			27			20
	Other debt, maturing 2027	4.77	%		8			—			—			—			—			8			—
	Tax-exempt bonds, maturing 2014 - 2041(c)	1.28	%		2,356			395			910			669			241			479			573
	Notes payable and commercial paper(d)	1.02	%		1,289			—			—			—			—			—			—
	Money pool/intercompany borrowings				—			300			1,213			462			181			43			150
	Fair value hedge carrying value adjustment				9			9			—			—			—			—			—
	Unamortized debt discount and premium, net(e)				1,977			(16		)	(27		)	(12		)	(9		)	(31		)	(10		)
	Total debt	4.52	%		$	41,095		$	8,436		$	15,328		$	5,697		$	5,067		$	2,231		$	3,796
	Short-term notes payable and commercial paper				(839		)	—			—			—			—			—			—
	Short-term money pool borrowings				—			—			(1,213		)	(462		)	(181		)	(43		)	—
	Current maturities of long-term debt(f)				(2,104		)	(47		)	(485		)	(174		)	(11		)	(47		)	(5		)
	Total long-term debt(f)	4.59	%		$	38,152		$	8,389		$	13,630		$	5,061		$	4,875		$	2,141		$	3,791
	(a)    Substantially all electric utility property is mortgaged under mortgage bond indentures.
	(b)	Duke Energy includes $144 million and $838 million of capital lease purchase accounting adjustments related to Duke Energy Progress and Duke Energy Florida, respectively, related to power purchase agreements that are not accounted for as capital leases in their respective financial statements because of grandfathering provisions in GAAP.
	(c)	Substantially all tax-exempt bonds are secured by first mortgage bonds or letters of credit.
	(d)	Includes $450 million that was classified as Long-Term Debt on the Consolidated Balance Sheets due to the existence of long-term credit facilities that back-stop these commercial paper balances, along with Duke Energy’s ability and intent to refinance these balances on a long-term basis. The weighted-average days to maturity was 49 days.
	(e)	Duke Energy includes $2,067 million in purchase accounting adjustments related to the merger with Progress Energy. See Note 2 for additional information.
	(f)	Refer to Note 17 for additional information on amounts from consolidated VIE’s.
	Current Maturities of Long-Term Debt
	The following table shows the significant components of Current maturities of Long-Term Debt on the Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings.
	(in millions)	Maturity Date		Interest Rate			December 31, 2014
	Unsecured Debt
	Duke Energy (Parent)	Apr-15		3.35	%		$	450
	First Mortgage Bonds
	Duke Energy Ohio	Mar-15		0.375	%		150
	Duke Energy Progress	Apr-15		5.15	%		300
	Duke Energy Carolinas	Oct-15		5.3	%		500
	Duke Energy Florida	Nov-15		0.65	%		250
	Duke Energy Florida	Dec-15		5.1	%		300
	Duke Energy Progress	Dec-15		5.25	%		400
	Tax-exempt Bonds
	Duke Energy Progress	Jan-15		0.108	%		243
	Other						214
	Current maturities of long-term debt						$	2,807
Maturities and Call Options
The following table shows the annual maturities of long-term debt for the next five years and thereafter. Amounts presented exclude short-term notes payable and commercial paper and money pool borrowings for the Subsidiary Registrants.
	December 31, 2014
(in millions)	Duke Energy(a)				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio				Duke Energy Indiana
2015	$	2,793			$	507			$	1,507			$	945			$	562			$	157			$	5
2016	2,980				756				614				302				12				57				480
2017	2,452				116				940				453				487				3				3
2018	3,207				1,505				515				3				512				28				153
2019	2,810				5				1,418				606				12				552				62
Thereafter	23,803				5,502				9,760				3,892				3,275				969				3,088
Total long-term debt, including current maturities	$	38,045			$	8,391			$	14,754			$	6,201			$	4,860			$	1,766			$	3,791
(a)	Excludes $1,975 million in purchase accounting adjustments related to the merger with Progress Energy. See Note 2 for additional information.
The Duke Energy Registrants have the ability under certain debt facilities to call and repay the obligation prior to its scheduled maturity. Therefore, the actual timing of future cash repayments could be materially different than as presented above.
Short-Term Obligations Classified as Long-Term Debt
Tax-exempt bonds that may be put to the Duke Energy Registrants at the option of the holder and certain commercial paper issuances and money pool borrowings are classified as Long-Term Debt on the Consolidated Balance Sheets. These tax-exempt bonds, commercial paper issuances and money pool borrowings, which are short-term obligations by nature, are classified as long term due to Duke Energy’s intent and ability to utilize such borrowings as long-term financing. As Duke Energy’s Master Credit Facility and other bilateral letter of credit agreements have non-cancelable terms in excess of one year as of the balance sheet date, Duke Energy has the ability to refinance these short-term obligations on a long-term basis. The following tables show short-term obligations classified as long-term debt.
	December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Duke Energy Ohio				Duke Energy Indiana
Tax-exempt bonds	$	347			$	35			$	27			$	285
Commercial paper	475				300				25				150
Secured debt(a)	200				—				—				—
Total	$	1,022			$	335			$	52			$	435
	December 31, 2013
(in millions)	Duke Energy				Duke Energy Carolinas				Duke Energy Ohio				Duke Energy Indiana
Tax exempt bonds	$	471			$	75			$	111			$	285
Commercial paper	450				300				—				150
Secured debt(a)	200				—				—				—
Total	$	1,121			$	375			$	111			$	435
(a)	Instrument has a term of less than one year with the right to extend the maturity date for additional one-year periods with a final maturity date no later than December 2026.
Summary of Significant Debt Issuances
The following tables summarize significant debt issuances (in millions).
						Year Ended December 31, 2014
Issuance Date	Maturity Date		Interest Rate			Duke Energy (Parent)				Duke Energy Progress				Duke Energy Florida				Duke Energy
Unsecured Debt
April 2014(a)	Apr-24		3.75	%		600				—				—				600
April 2014(a)(b)	Apr-17		0.613	%		400				—				—				400
June 2014(c)	May-19		11.97	%		—				—				—				108
June 2014(c)	May-21		13.68	%		—				—				—				110
Secured Debt
March 2014(d)	Mar-17		0.863	%		—				—				225				225
July 2014(e)	Jul-36		5.34	%		—				—				—				129
First Mortgage Bonds
March 2014(f)	Mar-44		4.375	%		—				400				—				400
March 2014(f)(g)	Mar-17		0.435	%		—				250				—				250
November 2014(h)	Dec-44		4.15	%		—				500				—				500
November 2014(g)(h)	Nov-17		0.432	%		—				200				—				200
Total issuances						$	1,000			$	1,350			$	225			$	2,922
(a)	Proceeds were used to redeem $402 million of tax-exempt bonds at Duke Energy Ohio, the repayment of outstanding commercial paper and for general corporate purposes. See Note 13 for additional information related to the redemption of Duke Energy Ohio's tax-exempt bonds.
(b)	The debt is floating rate based on three-month London Interbank Offered Rate (LIBOR) plus a fixed credit spread of 38 basis points.
(c)	Proceeds were used to repay $196 million of debt for International Energy and for general corporate purposes.
(d)	Relates to the securitization of accounts receivable at a subsidiary of Duke Energy Florida. Proceeds were used to repay short-term borrowings under the intercompany money pool borrowing arrangement and for general corporate purposes. See Note 17 for further details.
(e)	Proceeds were used to fund a portion of Duke Energy's prior investment in the existing Wind Star renewables portfolio.
(f)	Proceeds were used to repay short-term borrowings under the intercompany money pool borrowing arrangement and for general corporate purposes.
(g)	The debt is floating rate based on three-month LIBOR plus a fixed credit spread of 20 basis points.
(h)	Proceeds will be used to redeem $450 million of tax-exempt bonds, repay short-term borrowings under the intercompany money pool borrowing arrangement and for general corporate purposes.
						Year Ended December 31, 2013
Issuance Date	Maturity Date		Interest Rate			Duke Energy (Parent)				Duke Energy Progress				Duke Energy Ohio				Duke Energy Indiana				Duke Energy
Unsecured Debt
January 2013(a)	Jan-73		5.125	%		$	500			$	—			$	—			$	—			$	500
June 2013(b)	Jun-18		2.1	%		500				—				—				—				500
August 2013(c)(d)	Aug-23		11	%		―				—				—				—				220
October 2013(e)	Oct-23		3.95	%		400				—				—				—				400
Secured Debt
February 2013(f)(g)	Dec-30		2.043	%		—				—				—				—				203
February 2013(f)	Jun-37		4.74	%		—				—				—				—				220
April 2013(h)	Apr-26		5.456	%		—				—				—				—				230
December 2013(i)	Dec-16		0.852	%		—				300				—				—				300
First Mortgage Bonds
March 2013(j)	Mar-43		4.1	%		—				500				—				—				500
July 2013(k)	Jul-43		4.9	%		—				—				—				350				350
July 2013(k)(l)	Jul-16		0.619	%		—				—				—				150				150
September 2013(m)	Sep-23		3.8	%		—				—				300				—				300
September 2013(m)(n)	Mar-15		0.4	%		—				—				150				—				150
Total issuances						$	1,400			$	800			$	450			$	500			$	4,023
(a)	Callable after January 2018 at par. Proceeds were used to redeem the $300 million 7.10% Cumulative Quarterly Income Preferred Securities (QUIPS) and to repay a portion of outstanding commercial paper and for general corporate purposes.
(b)	Proceeds were used to repay $250 million of current maturities and for general corporate purposes, including the repayment of outstanding commercial paper.
(c)	Proceeds were used to repay $200 million of current maturities. The maturity date included above applies to half of the instrument. The remaining half matures in August 2018.
(d)	The debt is floating rate based on a consumer price index and an overnight funds rate in Brazil. The debt is denominated in Brazilian Real.
(e)	Proceeds were used to repay commercial paper as well as for general corporate purposes.
(f)	Represents the conversion of construction loans related to two renewable energy projects issued in December 2012 to term loans. No cash proceeds were received in conjunction with the conversion. The term loans have varying maturity dates. The maturity date presented represents the latest date for all components of the respective loans.
(g)	The debt is floating rate. Duke Energy has entered into a pay fixed-receive floating interest rate swap for 95 percent of the loans.
(h)	Represents the conversion of a $190 million bridge loan issued in conjunction with the acquisition of Ibener in December 2012. Duke Energy received incremental proceeds of $40 million upon conversion of the bridge loan. The debt is floating rate and is denominated in U.S. dollars. Duke Energy has entered into a pay fixed-receive floating interest rate swap for 75 percent of the loan.
(i)	Relates to the securitization of accounts receivable at a subsidiary of Duke Energy Progress; the proceeds were used to repay short-term debt. See Note 17 for further details.
(j)	Proceeds were used to repay notes payable to affiliated companies as well as for general corporate purposes.
(k)	Proceeds were used to repay $400 million of current maturities.
(l)	The debt is floating rate based on three-month LIBOR and a fixed credit spread of 35 basis points.
(m)	Proceeds were used for general corporate purposes including the repayment of short-term notes payable, a portion of which was incurred to fund the retirement of $250 million of first mortgage bonds that matured in the first half of 2013.
(n)	The debt is floating rate based on three-month LIBOR plus a fixed credit spread of 14 basis points.
Available Credit Facilities
At December 31, 2014, Duke Energy had a Master Credit Facility with a capacity of $6 billion through December 2018. In January 2015, Duke Energy amended the Master Credit Facility to increase its capacity to $7.5 billion through January 2020. The Duke Energy Registrants, excluding Progress Energy, each have borrowing capacity under the Master Credit Facility up to specified sublimits for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower. The amount available under the Master Credit Facility has been reduced to backstop the issuances of commercial paper, certain letters of credit and variable-rate demand tax-exempt bonds that may be put to the Duke Energy Registrants at the option of the holder. The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility.
	December 31, 2014
(in millions)	Duke Energy				Duke Energy (Parent)				Duke Energy Carolinas				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio				Duke Energy Indiana
Facility size(a)	$	6,000			$	2,250			$	1,000			$	750			$	650			$	650			$	700
Reduction to backstop issuances
Commercial paper(b)	(2,021		)		(1,479		)		(300		)		—				(29		)		(38		)		(175		)
Outstanding letters of credit	(70		)		(62		)		(4		)		(2		)		(1		)		—				(1		)
Tax-exempt bonds	(116		)		—				(35		)		—				—				—				(81		)
Available capacity	$	3,793			$	709			$	661			$	748			$	620			$	612			$	443
(a)	Represents the sublimit of each borrower.
(b)	Duke Energy issued $475 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies in the Consolidated Balance Sheets.
On February 20, 2015, Duke Energy Carolinas, Duke Energy Progress and DEBS, a wholly owned subsidiary of Duke Energy, each entered into the Plea Agreements in connection with the investigation initiated by the USDOJ. Under the terms of the Plea Agreements, Duke Energy Carolinas and Duke Energy Progress are required to each maintain $250 million of available capacity under the Master Credit Facility as security to meet their obligations under the Plea Agreements, in addition to certain other conditions set out in the Plea Agreements. The Plea Agreements are subject to court approval. See Note 5 for further details.
Other Debt Matters
In September 2013, Duke Energy filed a registration statement (Form S-3) with the Securities and Exchange Commission (SEC). Under this Form S-3, which is uncapped, the Duke Energy Registrants, excluding Progress Energy, may issue debt and other securities in the future at amounts, prices and with terms to be determined at the time of future offerings. The registration statement also allows for the issuance of common stock by Duke Energy.
Duke Energy has an effective Form S-3 with the SEC to sell up to $3 billion of variable denomination floating-rate demand notes, called PremierNotes. The Form S-3 states that no more than $1.5 billion of the notes will be outstanding at any particular time. The notes are offered on a continuous basis and bear interest at a floating rate per annum determined by the Duke Energy PremierNotes Committee, or its designee, on a weekly basis. The interest rate payable on notes held by an investor may vary based on the principal amount of the investment. The notes have no stated maturity date, are non-transferable and may be redeemed in whole or in part by Duke Energy or at the investor’s option at any time. The balance as of December 31, 2014 and 2013 was $968 million and $836 million, respectively. The notes are short-term debt obligations of Duke Energy and are reflected as Notes payable and commercial paper on Duke Energy’s Consolidated Balance Sheets.
At December 31, 2014 and 2013, $767 million and $811 million, respectively, of debt issued by Duke Energy Carolinas was guaranteed by Duke Energy.
Money Pool
The Subsidiary Registrants, excluding Progress Energy receive support for their short-term borrowing needs through participation with Duke Energy and certain of its subsidiaries in a money pool arrangement. Under this arrangement, those companies with short-term funds may provide short-term loans to affiliates participating in this arrangement. The money pool is structured such that the Subsidiary Registrants, excluding Progress Energy, separately manage their cash needs and working capital requirements. Accordingly, there is no net settlement of receivables and payables between money pool participants. Duke Energy (Parent), may loan funds to its participating subsidiaries, but may not borrow funds through the money pool. Accordingly, as the money pool activity is between Duke Energy and its wholly owned subsidiaries, all money pool balances are eliminated within Duke Energy’s Consolidated Balance Sheets.
Money pool receivable balances are reflected within Notes receivable from affiliated companies on the Subsidiary Registrants’ Consolidated Balance Sheets. Money pool payable balances are reflected within either Notes payable to affiliated companies or Long-Term Debt Payable to Affiliated Companies on the Subsidiary Registrants’ Consolidated Balance Sheets.
Restrictive Debt Covenants
The Duke Energy Registrants’ debt and credit agreements contain various financial and other covenants. The Master Credit Facility contains a covenant requiring the debt-to-total capitalization ratio not exceed 65 percent for each borrower. Failure to meet those covenants beyond applicable grace periods could result in accelerated due dates and/or termination of the agreements. As of December 31, 2014, each of the Duke Energy Registrants were in compliance with all covenants related to their significant debt agreements. In addition, some credit agreements may allow for acceleration of payments or termination of the agreements due to nonpayment, or acceleration of other significant indebtedness of the borrower or some of its subsidiaries. None of the significant debt or credit agreements contain material adverse change clauses.
Other Loans
During 2014 and 2013, Duke Energy and Duke Energy Progress had loans outstanding against the cash surrender value of life insurance policies it owns on the lives of its executives. The amounts outstanding were $603 million, including $44 million at Duke Energy Progress and $571 million, including $48 million at Duke Energy Progress as of December 31, 2014 and 2013, respectively. The amounts outstanding were carried as a reduction of the related cash surrender value that is included in Other within Investments and Other Assets on the Consolidated Balance Sheets.

Guarantees_and_Indemnification

Guarantees and Indemnifications	12 Months Ended
	Dec. 31, 2014
Guarantees [Abstract]
Guarantees and Indemnifications	GUARANTEES AND INDEMNIFICATIONS
	Duke Energy and Progress Energy have various financial and performance guarantees and indemnifications, which are issued in the normal course of business. As discussed below, these contracts include performance guarantees, stand-by letters of credit, debt guarantees, surety bonds and indemnifications. Duke Energy and Progress Energy enter into these arrangements to facilitate commercial transactions with third parties by enhancing the value of the transaction to the third party. At December 31, 2014, Duke Energy and Progress Energy do not believe conditions are likely for significant performance under these guarantees. To the extent liabilities are incurred as a result of the activities covered by the guarantees, such liabilities are included on the accompanying Consolidated Balance Sheets.
	On January 2, 2007, Duke Energy completed the spin-off of its natural gas businesses to shareholders. Guarantees issued by Duke Energy or its affiliates, or assigned to Duke Energy prior to the spin-off, remained with Duke Energy subsequent to the spin-off. Guarantees issued by Spectra Energy Capital, LLC, formerly known as Duke Capital LLC, (Spectra Capital) or its affiliates prior to the spin-off remained with Spectra Capital subsequent to the spin-off, except for guarantees that were later assigned to Duke Energy. Duke Energy has indemnified Spectra Capital against any losses incurred under certain of the guarantee obligations that remain with Spectra Capital. At December 31, 2014, the maximum potential amount of future payments associated with these guarantees was $205 million, the majority of which expires by 2028.
	Duke Energy has issued performance guarantees to customers and other third parties that guarantee the payment and performance of other parties, including certain non-wholly owned entities, as well as guarantees of debt of certain non-consolidated entities and less than wholly owned consolidated entities. If such entities were to default on payments or performance, Duke Energy would be required under the guarantees to make payments on the obligations of the less than wholly owned entity. The maximum potential amount of future payments required under these guarantees as of December 31, 2014, was $267 million. Of this amount, $15 million relates to guarantees issued on behalf of less than wholly owned consolidated entities, with the remainder related to guarantees issued on behalf of third parties and unconsolidated affiliates of Duke Energy. Of the guarantees noted above, $120 million of the guarantees expire between 2015 and 2033, with the remaining performance guarantees having no contractual expiration.
	Duke Energy has guaranteed certain issuers of surety bonds, obligating itself to make payment upon the failure of a wholly owned and former non-wholly owned entity to honor its obligations to a third party. Under these arrangements, Duke Energy has payment obligations that are triggered by a draw by the third party or customer due to the failure of the wholly owned or former non-wholly owned entity to perform according to the terms of its underlying contract. At December 31, 2014, Duke Energy had guaranteed $44 million of outstanding surety bonds, most of which have no set expiration.
	Duke Energy uses bank-issued stand-by letters of credit to secure the performance of wholly owned and non-wholly owned entities to a third party or customer. Under these arrangements, Duke Energy has payment obligations to the issuing bank which are triggered by a draw by the third party or customer due to the failure of the wholly owned or non-wholly owned entity to perform according to the terms of its underlying contract. At December 31, 2014, Duke Energy had issued a total of $452 million in letters of credit, which expire between 2015 and 2020. The unused amount under these letters of credit was $46 million.
	Duke Energy and Progress Energy have issued indemnifications for certain asset performance, legal, tax and environmental matters to third parties, including indemnifications made in connection with sales of businesses. At December 31, 2014, the estimated maximum exposure for these indemnifications was $107 million, the majority of which expires in 2017. Of this amount, $7 million has no contractual expiration. For certain matters for which Progress Energy receives timely notice, indemnity obligations may extend beyond the notice period. Certain indemnifications related to discontinued operations have no limitations as to time or maximum potential future payments.
	The following table includes the liabilities recognized for the guarantees discussed above. These amounts are primarily recorded in Other within Deferred Credits and other Liabilities on the Consolidated Balance Sheets. As current estimates change, additional losses related to guarantees and indemnifications to third parties, which could be material, may be recorded by the Duke Energy Registrants in the future.
		December 31,
		2014		2013
	Duke Energy	$	28	$	24
	Progress Energy	13		9
	Duke Energy Florida	7		3

Joint_Ownership_of_Generating_

Joint Ownership of Generating and Transmission Facilities	12 Months Ended
	Dec. 31, 2014
Joint Ownership Of Generating And Transmission Facilities [Abstract]
Joint Ownership of Generating and Transmission Facilities	JOINT OWNERSHIP OF GENERATING AND TRANSMISSION FACILITIES
	The Duke Energy Registrants hold ownership interests in certain jointly owned generating and transmission facilities. The Duke Energy Registrants are entitled to shares of the generating capacity and output of each unit equal to their respective ownership interests, except as outlined below. The Duke Energy Registrants pay their ownership share of additional construction costs, fuel inventory purchases and operating expenses, except in certain instances where agreements have been executed to limit certain joint owners’ maximum exposure to the additional costs. The Duke Energy Registrants share of revenues and operating costs of the jointly owned generating facilities is included within the corresponding line in the Consolidated Statements of Operations. Each participant in the jointly owned facilities must provide its own financing, except in certain instances where agreements have been executed to limit certain joint owners’ maximum exposure to the additional costs.
	The following table presents the share of jointly owned plant or facilities included on the Consolidated Balance Sheets. All facilities are operated by the Duke Energy Registrants unless otherwise noted.
		December 31, 2014
		Ownership Share		Property, Plant and Equipment		Accumulated Depreciation		Construction Work in Progress
	Duke Energy Carolinas
	Catawba Nuclear Station (Units 1 and 2)(a)(b)	19.25	%	$	886	$	534	$	29
	Duke Energy Progress
	Mayo Station(a)(c)	83.83	%	1,111		360		10
	Shearon Harris Nuclear Station(a)(c)	83.83	%	3,872		2,242		208
	Brunswick Nuclear Station(a)(c)	81.67	%	2,673		1,372		290
	Roxboro Station (Unit 4)(a)(c)	87.06	%	954		514		24
	Duke Energy Florida
	Crystal River Nuclear Station (Unit 3)(a)(d)	91.78	%	—		—		—
	Intercession City Station (Unit P11)(a)	(e)		24		14		—
	Duke Energy Ohio
	Miami Fort Station (Units 7 and 8)(f)(g)	64	%	—		—		—
	J.M. Stuart Station(f)(h)(i)	39	%	—		—		—
	Conesville Station (Unit 4)(f)(h)(i)	40	%	—		—		—
	W.M. Zimmer Station(f)(h)	46.5	%	—		—		—
	Killen Station(f)(g)(i)	33	%	—		—		—
	Transmission facilities(a)(h)	Various		96		51		1
	Duke Energy Indiana
	Gibson Station (Unit 5)(a)(j)	50.05	%	315		170		6
	Vermillion(a)(k)	62.5	%	154		105		—
	Transmission and local facilities(a)(j)	Various		3,918		1,633		—
	International Energy
	Brazil - Canoas I and II(l)	47.2	%	235		78		—
	(a)	Included in Regulated Utilities segment.
	(b)	Jointly owned with North Carolina Municipal Power Agency Number 1, NCEMC and Piedmont Municipal Power Agency.
	(c)	Jointly owned with NCEMPA. Duke Energy Progress executed an agreement in September 2014 to purchase NCEMPA's ownership interest in these facilities. See Note 2 for further discussion.
	(d)	All costs associated with Crystal River Unit 3 are included within Regulatory assets on the Consolidated Balance Sheets of Duke Energy, Progress Energy and Duke Energy Florida. See Note 4 for additional information. Co-owned with Seminole Electric Cooperative, Inc., City of Ocala, Orlando Utilities Commission, City of Gainesville, City of Leesburg, Kissimmee Utility Authority, Utilities Commission of the City of New Smyrna Beach, City of Alachua and City of Bushnell (Florida Municipal Joint Owners). Duke Energy Florida is in the process of obtaining the remaining ownership interest from the Florida Municipal Joint Owners.
	(e)	Jointly owned with Georgia Power Company (GPC). GPC has exclusive rights to the output of the unit during the months of June through September and pays all fuel and water costs during this period. Duke Energy Florida pays all fuel and water costs during the remaining months. Other costs are allocated 66.67 percent to Duke Energy Florida and the remainder to GPC.
	(f)	All costs associated with these plants are included in Assets held for sale on the Consolidated Balance Sheets of Duke Energy and Duke Energy Ohio as part of the Disposal Group. See Note 2 for further discussion.
	(g)	Jointly owned with The Dayton Power and Light Company.
	(h)	Jointly owned with America Electric Power Generation Resources and The Dayton Power and Light Company.
	(i)	Station is not operated by Duke Energy Ohio.
	(j)	Jointly owned with WVPA and Indiana Municipal Power Agency.
	(k)	Jointly owned with WVPA.
	(l)	Included in International Energy segment. Jointly owned with Companhia Brasileira de Aluminio.

Asset_Retirement_Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation [Abstract]
Asset Retirement Obligations	ASSET RETIREMENT OBLIGATIONS
	Asset retirement obligations recognized by Duke Energy Carolinas, Progress Energy and Duke Energy Progress relate primarily to decommissioning nuclear power facilities, closure of ash basins in North Carolina and South Carolina, asbestos removal and closure of landfills at fossil generation facilities. Asset retirement obligations recognized at Duke Energy Florida relate primarily to decommissioning nuclear power facilities, asbestos removal and closure of landfills at fossil generation facilities. Asset retirement obligations at Duke Energy Ohio relate primarily to the retirement of natural gas mains, asbestos removal and closure of landfills at fossil generation facilities. Asset retirement obligations at Duke Energy Indiana relate primarily to obligations associated with asbestos removal and closure of landfills at fossil generation facilities. Duke Energy also has asset retirement obligations related to the removal of renewable energy generation assets in addition to the above items. Certain of the Duke Energy Registrants’ assets have an indeterminate life, such as transmission and distribution facilities, and thus the fair value of the retirement obligation is not reasonably estimable. A liability for these asset retirement obligations will be recorded when a fair value is determinable.
	The following table presents changes in the liability associated with asset retirement obligations.
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Balance at December 31, 2012(a)	$	5,176		$	1,959		$	2,420		$	1,656	$	764		$	28		$	37
	Acquisitions	4			—			—			—		—			—			—
	Accretion expense(b)	239			122			113			80		33			2			—
	Liabilities settled	(12		)	—			(12		)	—		(12		)	—			—
	Revisions in estimates of cash flows(c)	(449		)	(487		)	49			1		48			(2		)	(7		)
	Balance at December 31, 2013(a)	4,958			1,594			2,570			1,737		833			28			30
	Acquisitions	4			—			—			—		—			—			—
	Accretion expense(b)	246			113			135			97		38			2			2
	Liabilities settled(d)	(68		)	—			(68		)	—		(68		)	—			—
	Liabilities incurred in the current year(e)	3,500			1,717			1,783			1,783		—			—			—
	Revisions in estimates of cash flows(c)	(174		)	4			291			288		3			(3		)	—
	Balance at December 31, 2014	$	8,466		$	3,428		$	4,711		$	3,905	$	806		$	27		$	32
	(a)	Balances at December 31, 2013 and 2012, include $8 million and $7 million, respectively, reported in Other current liabilities on the Consolidated Balance Sheets at Duke Energy, Progress Energy and Duke Energy Progress.
	(b)	Substantially all accretion expense for the years ended December 31, 2014 and 2013 relates to Duke Energy’s regulated electric operations and has been deferred in accordance with regulatory accounting treatment.
	(c)	For 2014, amounts for Duke Energy, Progress Energy and Duke Energy Progress primarily relate to Duke Energy Progress' site-specific nuclear decommissioning cost studies. Amounts at Duke Energy also include impacts from Duke Energy Progress' site-specific nuclear decommissioning cost studies on purchase accounting amounts. For 2013, amounts for Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Florida primarily relate to the site-specific nuclear decommissioning cost studies.
	(d)	Amounts relate to liability settlements for Crystal River Unit 3.
	(e)	Amounts primarily relate to asset retirement obligations recorded as a result of the Coal Ash Act and an agreement with the SCDHEC related to the W.S. Lee Steam Station.
	The Duke Energy Registrants’ regulated operations accrue costs of removal for property that does not have an associated legal retirement obligation based on regulatory orders from state commissions. These costs of removal are recorded as a regulatory liability in accordance with regulatory accounting treatment. The Duke Energy Registrants do not accrue the estimated cost of removal for any nonregulated assets. See Note 4 for the estimated cost of removal for assets without an associated legal retirement obligation, which are included in Regulatory liabilities on the Consolidated Balance Sheets.
	Ash Basins
	As of December 31, 2014, as a result of the Coal Ash Act and the agreement with SCDHEC discussed in Note 5, Duke Energy Carolinas and Duke Energy Progress have asset retirement obligations in the amount of $1,735 million and $1,792 million, respectively, related to closure of ash basins in North Carolina and South Carolina.
	The asset retirement obligation amount is based upon estimated ash basin closure costs for each of Duke Energy's 32 ash basins located at 14 plants in North Carolina and an ash basin and ash fill area at a plant in South Carolina. The amount recorded represents the discounted cash flows for estimated ash basin closure costs based upon probability weightings of the potential closure methods as evaluated on a site by site basis. Actual costs to be incurred will be dependent upon factors that vary from site to site. The most significant factors are the method and timeframe of closure at the individual sites. Closure methods considered include removing the water from the basins and capping the ash with a synthetic barrier, excavating and relocating the ash to a lined structural fill or lined landfill, or recycling the ash for concrete or some other beneficial use. The ultimate method and timetable for closure will be in compliance with future standards set by the Coal Ash Management Commission established by the Coal Ash Act. The asset retirement obligation amounts will be adjusted as additional information is gained from the Coal Ash Management Commission on acceptable compliance approaches which may change management assumptions.
	Asset retirement costs associated with the asset retirement obligations for operating plants and retired plants are included in Net property, plant and equipment, and Regulatory assets, respectively, on the Consolidated Balance Sheets. Of the asset retirement obligations recorded, $896 million and $603 million were recorded in Net property, plant and equipment for Duke Energy Carolinas and Duke Energy Progress, respectively, and $839 million and $1,152 million were recorded in Regulatory assets for Duke Energy Carolinas and Duke Energy Progress, respectively. The asset retirement costs recorded for Duke Energy Progress are net of $37 million of Regulatory liabilities related to cost of removal. Cost recovery for these expenditures is believed to be probable and will be pursued through the normal ratemaking process with the NCUC, PSCSC and FERC.
	In December 2014, the EPA signed the first regulation for the disposal of CCR. The federal regulation classifies CCR as nonhazardous waste. The regulation applies to all new and existing landfills, new and existing surface impoundments, structural fills and CCR piles. The law establishes requirements regarding landfill design, structural integrity design and assessment criteria for surface impoundments, groundwater monitoring and protection procedures and other operational and reporting procedures to ensure the safe disposal and management of CCR. Once the rule is effective in 2015, additional ARO amounts will be recorded at the Duke Energy Registrants. For more information, see Note 5.
	Nuclear Decommissioning Costs
	Use of the NDTF investments are restricted to nuclear decommissioning activities. The NDTF investments are managed and invested in accordance with applicable requirements of various regulatory bodies, including the NRC, FERC, NCUC, PSCSC, FPSC and the Internal Revenue Service (IRS). The fair value of assets legally restricted for purposes of settling asset retirement obligations associated with nuclear decommissioning are $5,182 million and $2,678 million for Duke Energy and Duke Energy Carolinas at December 31, 2014, respectively, and $4,769 million and $2,477 million for Duke Energy and Duke Energy Carolinas at December 31, 2013, respectively. The NDTF balances for Progress Energy, Duke Energy Progress and Duke Energy Florida represent the fair value of assets legally restricted for purposes of settling asset retirement obligations associated with nuclear decommissioning. The NCUC, PSCSC and FPSC require updated cost estimates for decommissioning nuclear plants every five years.
	The following table summarizes information about nuclear decommissioning cost studies.
	(in millions)	Annual Funding Requirement			Decommissioning Costs(a)(b)(c)			Year of Cost Study
	Duke Energy Carolinas(d)	$	21		$	3,420		2013
	Duke Energy Progress(e)	14			3,062			2014
	Duke Energy Florida	—			1,083			2013
	(a)	Represents cost per the most recent site-specific nuclear decommissioning cost studies, including costs to decommission plant components not subject to radioactive contamination.
	(b)	Includes the Subsidiary Registrants' ownership interest in jointly owned reactors. Other joint owners are responsible for decommissioning costs related to their interest in the reactors.
	(c)	Amounts are in dollars of year of cost study.
	(d)	In the fourth quarter of 2014, Duke Energy Carolinas requested from the NCUC a reduction in the annual funding requirement to zero. Duke Energy Carolinas received approval from the NCUC in January 2015.
	(e)	Duke Energy Progress' site-specific cost nuclear decommissioning cost studies are expected to be filed with the NCUC and PSCSC by the second quarter of 2015. Duke Energy Progress will also complete a new funding study, which will be completed and filed with the NCUC and PSCSC in 2015.
	Nuclear Operating Licenses
	Operating licenses for nuclear units are potentially subject to extension. The following table includes the current expiration of nuclear operating licenses.
	Unit	Year of Expiration
	Duke Energy Carolinas
	Catawba Unit 1	2043
	Catawba Unit 2	2043
	McGuire Unit 1	2041
	McGuire Unit 2	2043
	Oconee Unit 1	2033
	Oconee Unit 2	2033
	Oconee Unit 3	2034
	Duke Energy Progress
	Brunswick Unit 1	2036
	Brunswick Unit 2	2034
	Harris	2046
	Robinson	2030
	Duke Energy Florida
	Crystal River Unit 3	(a)
	(a)	Duke Energy Florida has requested the NRC terminate the operating license as Crystal River Unit 3 permanently ceased operation in February 2013. Refer to Note 4 for further information on decommissioning activity and transition to SAFSTOR.

Property_Plant_and_Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT
	The following tables summarize the property, plant and equipment.
		31-Dec-14
	(in millions)	Estimated Useful Life (Years)		Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Land			$	1,459			$	403			$	704		$	380		$	324		$	114		$	108
	Plant - Regulated
	Electric generation, distribution and transmission	2 - 138		82,206				31,751				33,672			20,616			13,056			3,956			11,911
	Natural gas transmission and distribution	Dec-67		2,230				—				—			—			—			2,230			—
	Other buildings and improvements	9 - 100		1,445				465				607			286			318			200			173
	Plant - Nonregulated
	Electric generation, distribution and transmission	30-Jan		2,380				—				—			—			—			—			—
	Other buildings and improvements	May-50		2,498				—				—			—			—			—			—
	Nuclear fuel			2,865				1,676				1,190			1,190			—			—			—
	Equipment	Mar-34		1,762				341				506			388			118			330			166
	Construction in process			4,519				2,081				1,215			908			307			97			481
	Other	May-80		3,497				655				756			439			310			214			195
	Total property, plant and equipment(a)(d)			104,861				37,372				38,650			24,207			14,433			7,141			13,034
	Total accumulated depreciation - regulated(b)(c)(d)			(32,628		)		(12,700		)		(13,506		)	(9,021		)	(4,478		)	(2,213		)	(4,219		)
	Total accumulated depreciation - nonregulated(c)(d)			(2,196		)		—				—			—			—			—			—
	Generation facilities to be retired, net			9				—				—			—			—			9			—
	Total net property, plant and equipment			$	70,046			$	24,672			$	25,144		$	15,186		$	9,955		$	4,937		$	8,815
	(a)	Includes capitalized leases of $1,548 million, $40 million, $315 million, $146 million, $169 million, $98 million, and $30 million at Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, and Duke Energy Indiana, respectively, primarily in regulated plant. The Progress Energy, Duke Energy Progress and Duke Energy Florida amounts are net of $72 million, $5 million and $67 million, respectively, of accumulated amortization of capitalized leases.
	(b)	Includes $1,408 million, $847 million, $561 million and $561 million of accumulated amortization of nuclear fuel at Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Progress, respectively.
	(c)	Includes accumulated amortization of capitalized leases of $52 million, $8 million, $25 million and $6 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana, respectively.
	(d)	Includes gross property, plant and equipment cost of consolidated VIEs of $1,873 million and accumulated depreciation of consolidated VIEs of $257 million at Duke Energy.
		31-Dec-13
	(in millions)	Estimated Useful Life (Years)		Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Land			$	1,481			$	397			$	705		$	383		$	321		$	137		$	105
	Plant - Regulated
	Electric generation, distribution and transmission	2 - 125		78,272				30,018				31,792			19,190			12,601			3,925			11,594
	Natural gas transmission and distribution	Dec-67		2,138				—				—			—			—			2,138			—
	Other buildings and improvements	2 - 100		1,397				447				610			282			315			190			159
	Plant - Nonregulated
	Electric generation, distribution and transmission	2 - 100		6,267				—				—			—			—			4,017			—
	Other buildings and improvements	9 -100		2,512				—				—			—			—			5			—
	Nuclear fuel			2,458				1,446				1,012			1,012			—			—			—
	Equipment	Jan-33		1,557				287				621			357			94			317			146
	Construction in process			3,595				1,741				873			631			238			166			307
	Other	May-33		3,438				570				867			418			294			248			178
	Total property, plant and equipment(a)(d)			103,115				34,906				36,480			22,273			13,863			11,143			12,489
	Total accumulated depreciation - regulated(b)(c)(d)			(31,659		)		(11,894		)		(13,098		)	(8,623		)	(4,252		)	(2,160		)	(3,913		)
	Total accumulated depreciation - nonregulated(c)(d)			(1,966		)		—				—			—			—			(748		)	—
	Total net property, plant and equipment			$	69,490			$	23,012			$	23,382		$	13,650		$	9,611		$	8,235		$	8,576
	(a)	Includes capitalized leases of $1,606 million, $53 million, $328 million, $148 million, $180 million, $96 million, and $30 million at Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, and Duke Energy Indiana, respectively, primarily in regulated plant. The Progress Energy, Duke Energy Progress and Duke Energy Florida amounts are net of $60 million, an insignificant amount and $57 million, respectively, of accumulated amortization of capitalized leases.
	(b)	Includes $1,118 million, $681 million, $438 million and $438 million of accumulated amortization of nuclear fuel at Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Progress, respectively.
	(c)	Includes accumulated amortization of capitalized leases of $40 million, $4 million, $21 million and $5 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana, respectively.
	(d)	Includes gross property, plant and equipment cost of consolidated VIEs of $1,678 million and accumulated depreciation of consolidated VIEs of $175 million at Duke Energy.
	The following table presents capitalized interest, which includes the debt component of AFUDC.
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Duke Energy	$	75			$	89			$	176
	Duke Energy Carolinas	38				41				72
	Progress Energy	11				19				41
	Duke Energy Progress	10				16				23
	Duke Energy Florida	1				3				18
	Duke Energy Ohio	10				11				13
	Duke Energy Indiana	6				9				39

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS
	Goodwill
	The following tables present goodwill by reportable operating segment for Duke Energy and Duke Energy Ohio.
	Duke Energy
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Total
	Balance at December 31, 2013
	Goodwill	$	15,950		$	326		$	935		$	17,211
	Accumulated impairment charges	—			—			(871		)	(871		)
	Balance at December 31, 2013, net of accumulated impairment charges	15,950			326			64			16,340
	Foreign exchange and other changes	—			(19		)	—			(19		)
	Balance at December 31, 2014
	Goodwill	15,950			307			935			17,192
	Accumulated impairment charges	—			—			(871		)	(871		)
	Balance at December 31, 2014, net of accumulated impairment charges	$	15,950		$	307		$	64		$	16,321
	Duke Energy Ohio
	(in millions)	Regulated Utilities			Commercial Power			Total
	Balance at December 31, 2013
	Goodwill	$	1,136		$	1,188		$	2,324
	Accumulated impairment charges	(216		)	(1,188		)	(1,404		)
	Balance at December 31, 2013, net of accumulated impairment charges	920			—			920
	Balance at December 31, 2014
	Goodwill	1,136			1,188			2,324
	Accumulated impairment charges	(216		)	(1,188		)	(1,404		)
	Balance at December 31, 2014, net of accumulated impairment charges	$	920		$	—		$	920
	Progress Energy
	Progress Energy's Goodwill is included in the Regulated Utilities operating segment and there are no accumulated impairment charges.
	Impairment Testing
	Duke Energy, Duke Energy Ohio and Progress Energy are required to perform an annual goodwill impairment test as of the same date each year and, accordingly, performs its annual impairment testing of goodwill as of August 31. Duke Energy, Duke Energy Ohio and Progress Energy update their test between annual tests if events or circumstances occur that would more likely than not reduce the fair value of a reporting unit below its carrying value. As the fair value of Duke Energy, Duke Energy Ohio and Progress Energy’s reporting units exceeded their respective carrying values at the date of the annual impairment analysis, no impairment charges were recorded in 2014.
	Intangible Assets
	The following tables show the carrying amount and accumulated amortization of intangible assets within Other on the Consolidated Balance Sheets of the Duke Energy Registrants at December 31, 2014 and 2013.
		December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida		Duke Energy Ohio (a)			Duke Energy Indiana
	Emission allowances	$	23		$	1		$	7		$	3		$	4	$	—		$	16
	Renewable energy certificates	97			25			69			69			—		3			—
	Gas, coal and power contracts	24			—			—			—			—		—			24
	Wind development rights	97			—			—			—			—		—			—
	Other	76			—			—			—			—		—			—
	Total gross carrying amounts	317			26			76			72			4		3			40
	Accumulated amortization - gas, coal and power contracts	(15		)	—			—			—			—		—			(15		)
	Accumulated amortization - wind development rights	(14		)	—			—			—			—		—			—
	Accumulated amortization - other	(25		)	—			—			—			—		—			—
	Total accumulated amortization	(54		)	—			—			—			—		—			(15		)
	Total intangible assets, net	$	263		$	26		$	76		$	72		$	4	$	3		$	25
	(a)	During 2014, Duke Energy Ohio reduced the carrying amount of OVEC to zero. A charge of $94 million is recorded in Impairment Charges on Duke Energy Ohio's Consolidated Statement of Operations. In addition, Duke Energy Ohio has emission allowances and renewable energy certificates that have been reclassified to Assets Held For Sale pending the sale of the Disposal Group. See Note 17 for further information.
		December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Emission allowances	$	63		$	1		$	21		$	3		$	18	$	20		$	21
	Renewable energy certificates	82			16			64			64			—		2			—
	Gas, coal and power contracts	180			—			—			—			—		156			24
	Wind development rights	86			—			—			—			—		—			—
	Other	76			—			—			—			—		—			—
	Total gross carrying amounts	487			17			85			67			18		178			45
	Accumulated amortization - gas, coal and power contracts	(73		)	—			—			—			—		(60		)	(13		)
	Accumulated amortization - wind development rights	(12		)	—			—			—			—		—			—
	Accumulated amortization - other	(24		)	—			—			—			—		—			—
	Total accumulated amortization	(109		)	—			—			—			—		(60		)	(13		)
	Total intangible assets, net	$	378		$	17		$	85		$	67		$	18	$	118		$	32
	Amortization Expense
	The following table presents amortization expense for gas, coal and power contracts, wind development rights and other intangible assets.
		December 31,
	(in millions)	2014			2013			2012
	Duke Energy	$	6		$	13		$	14
	Duke Energy Ohio	2			8			12
	Duke Energy Indiana	1			1			1
The table below shows the expected amortization expense for the next five years for intangible assets as of December 31, 2014. The expected amortization expense includes estimates of emission allowances consumption and estimates of consumption of commodities such as gas and coal under existing contracts, as well as estimated amortization related to the wind development projects. The amortization amounts discussed below are estimates and actual amounts may differ from these estimates due to such factors as changes in consumption patterns, sales or impairments of emission allowances or other intangible assets, delays in the in-service dates of wind assets, additional intangible acquisitions and other events.
(in millions)	2015			2016			2017			2018			2019
Duke Energy	$	11		$	8		$	7		$	7		$	7
Duke Energy Ohio	2			1			1			1			1
Duke Energy Indiana	5			3			2			2			2

Investments_in_Unconsolidated_

Investments in Unconsolidated Affiliates	12 Months Ended
	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Investment in Unconsolidated Affiliates	INVESTMENTS IN UNCONSOLIDATED AFFILIATES
	EQUITY METHOD INVESTMENTS
	Investments in domestic and international affiliates that are not controlled by Duke Energy, but over which it has significant influence, are accounted for using the equity method. As of December 31, 2014 and 2013, the carrying amount of investments in affiliates with carrying amounts greater than zero approximated the amount of underlying equity in net assets.
	The following table presents Duke Energy’s investments in unconsolidated affiliates accounted for under the equity method, as well as the respective equity in earnings, by segment.
		Years Ended December 31,
		2014					2013					2012
	(in millions)	Investments		Equity in earnings			Investments		Equity in earnings			Equity in earnings
	Regulated Utilities	$	3	$	(3	)	$	4	$	(1	)	$	(5	)
	International Energy	69		120			82		110			134
	Commercial Power	258		10			252		7			14
	Other	28		3			52		6			5
	Total	$	358	$	130		$	390	$	122		$	148
	During the years ended December 31, 2014, 2013 and 2012, Duke Energy received distributions from equity investments of $154 million, $144 million and $183 million, respectively, which are included in Other assets within Cash Flows from Operating Activities on the Consolidated Statements of Cash Flows.
	Significant investments in affiliates accounted for under the equity method are discussed below.
	International Energy
	Duke Energy owns a 25 percent indirect interest in NMC, which owns and operates a methanol and MTBE business in Jubail, Saudi Arabia.
	Commercial Power
	Investments accounted for under the equity method primarily consist of Duke Energy’s approximate 50 percent ownership interest in the five Catamount Sweetwater, LLC wind farm projects (Phase I-V), INDU Solar Holdings, LLC and DS Cornerstone, LLC. All of these entities own solar or wind power projects in the United States. Duke Energy also owns a 50 percent interest in Duke American Transmission Co., LLC, which builds, owns and operates electric transmission facilities in North America.
	Other
	On December 31, 2013, Duke Energy completed the sale of its 50 percent ownership interest in DukeNet, which owned and operated telecommunications businesses, to Time Warner Cable, Inc. After retiring existing DukeNet debt and payment of transaction expenses, Duke Energy received $215 million in cash proceeds and recorded a $105 million pretax gain in the fourth quarter of 2013.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS
	The Subsidiary Registrants engage in related party transactions, which are generally performed at cost and in accordance with the applicable state and federal commission regulations. Refer to the Consolidated Balance Sheets of the Subsidiary Registrants for balances due to or due from related parties. Material amounts related to transactions with related parties included in the Consolidated Statements of Operations and Comprehensive Income are presented in the following table.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Duke Energy Carolinas
	Corporate governance and shared service expenses(a)	$	851	$	927	$	1,112
	Indemnification coverages(b)	21		22		21
	JDA revenue(c)	133		121		18
	JDA expense(c)	198		116		91
	Progress Energy
	Corporate governance and shared services provided by Duke Energy(a)	$	732	$	290	$	63
	Corporate governance and shared services provided to Duke Energy(d)	—		96		47
	Indemnification coverages(b)	33		34		17
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Progress
	Corporate governance and shared service expenses(a)	$	386	$	266	$	254
	Indemnification coverages(b)	17		20		8
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Florida
	Corporate governance and shared service expenses(a)	$	346	$	182	$	186
	Indemnification coverages(b)	16		14		8
	Duke Energy Ohio
	Corporate governance and shared service expenses(a)	$	316	$	347	$	358
	Indemnification coverages(b)	13		15		15
	Duke Energy Indiana
	Corporate governance and shared service expenses(a)	$	384	$	422	$	419
	Indemnification coverages(b)	11		14		8
	(a)	The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(b)	The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(c)	Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Consolidated Statements of Operations and Comprehensive Income.
	(d)	In 2013 and 2012, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Consolidated Statements of Changes in Common Stockholder's Equity.
	In addition to the amounts presented above, the Subsidiary Registrants record the impact on net income of other affiliate transactions, including rental of office space, participation in a money pool arrangement, other operational transactions and their proportionate share of certain charged expenses. See Note 6 for more information regarding money pool. The net impact of these transactions was not material for the years ended December 31, 2014, 2013 and 2012 for the Subsidiary Registrants.
	As discussed in Note 17, certain trade receivables have been sold by Duke Energy Ohio and Duke Energy Indiana to CRC, an affiliate formed by a subsidiary of Duke Energy. The proceeds obtained from the sales of receivables are largely cash but do include a subordinated note from CRC for a portion of the purchase price.
	In January 2012, Duke Energy Ohio recorded a non-cash equity transfer of $28 million related to the sale of Vermillion to Duke Energy Indiana. Duke Energy Indiana recorded a non-cash after-tax equity transfer of $26 million for the purchase of Vermillion from Duke Energy Ohio. See Note 2 for further discussion.
	Duke Energy Commercial Asset Management (DECAM) is a nonregulated, indirect subsidiary of Duke Energy Ohio that owns generating plants included in the Disposal Group discussed in Note 2. DECAM's business activities include the execution of commodity transactions, third-party vendor and supply contracts, and service contracts for certain of Duke Energy’s nonregulated entities. The commodity contracts DECAM enters are accounted for as undesignated contracts or NPNS. Consequently, mark-to-market impacts of intercompany contracts with, and sales of power to, nonregulated entities are included in (Loss) Income from discontinued operations in Duke Energy Ohio’s Consolidated Statements of Operations and Comprehensive Income. These amounts totaled net expense of $24 million and $6 million and net revenue of $24 million, for the years ended December 31, 2014, 2013 and 2012, respectively.
	Because it is not a rated entity, DECAM receives credit support from Duke Energy or its nonregulated subsidiaries, not from the regulated utility operations of Duke Energy Ohio. DECAM meets its funding needs through an intercompany loan agreement from a subsidiary of Duke Energy. DECAM also has the ability to loan money to the subsidiary of Duke Energy. DECAM had an outstanding intercompany loan payable of $459 million and $43 million for the years ended December 31, 2014 and 2013, respectively, These amounts are recorded in Notes payable to affiliated companies on Duke Energy Ohio’s Consolidated Balance Sheets.
	As discussed in Note 6, in April 2014, Duke Energy issued $1 billion of senior unsecured notes. Proceeds from the issuances of approximately $400 million were loaned to DECAM, and such funds were ultimately used to redeem $402 million of tax-exempt bonds at Duke Energy Ohio. This transaction substantially completed the restructuring of Duke Energy Ohio’s capital structure to reflect appropriate debt and equity ratios for its regulated operations. The restructuring was completed in the second quarter of 2014, and resulted in the transfer of all of Duke Energy Ohio’s nonregulated generation assets, excluding Beckjord, out of its regulated public utility subsidiary and into DECAM.

Derivatives_and_Hedging

Derivatives and Hedging	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging	DERIVATIVES AND HEDGING
	The Duke Energy Registrants use commodity and interest rate contracts to manage commodity price and interest rate risks. The primary use of energy commodity derivatives is to hedge the generation portfolio against changes in the prices of electricity and natural gas. Interest rate swaps are used to manage interest rate risk associated with borrowings.
	All derivative instruments not identified as NPNS are recorded at fair value as assets or liabilities on the Consolidated Balance Sheets. Cash collateral related to derivative instruments executed under master netting agreement is offset against the collateralized derivatives on the balance sheet.
	Changes in the fair value of derivative agreements that either do not qualify for or have not been designated as hedges are reflected in current earnings or as regulatory assets or liabilities.
	COMMODITY PRICE RISK
	The Duke Energy Registrants are exposed to the impact of changes in the future prices of electricity, coal and natural gas. Exposure to commodity price risk is influenced by a number of factors including the term of contracts, the liquidity of markets, and delivery locations.
	Fair Value and Cash Flow Hedges
	At December 31, 2014, there were no open commodity derivative instruments designated as hedges.
	Undesignated Contracts
	Undesignated contracts may include contracts not designated as a hedge, contracts that do not qualify for hedge accounting, derivatives that do not or no longer qualify for the NPNS scope exception, and de-designated hedge contracts. These contracts expire as late as 2018.
	Duke Energy Carolinas’ undesignated contracts are primarily associated with forward sales and purchases of electricity. Duke Energy Progress’ and Duke Energy Florida’s undesignated contracts are primarily associated with forward purchases of natural gas. Duke Energy Ohio’s undesignated contracts are primarily associated with forward sales and purchases of electricity, coal, and natural gas. Duke Energy Indiana’s undesignated contracts are primarily associated with forward purchases and sales of electricity and financial transmission rights.
	Volumes
	The tables below show information relating to volumes of outstanding commodity derivatives. Amounts disclosed represent the notional volumes of commodity contracts excluding NPNS. Amounts disclosed represent the absolute value of notional amounts. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown.
		December 31, 2014
		Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Electricity (gigawatt-hours)(a)	25,370			—			—		—		—			19,141			—
	Natural gas (millions of decatherms)	676			35			328		116		212			313			—
		December 31, 2013
		Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Electricity (gigawatt-hours)(a)	71,466			1,205			925		925		—			69,362			203
	Natural gas (millions of decatherms)	636			—			363		141		222			274			—
	(a)	Amounts at Duke Energy Ohio include intercompany positions that eliminate at Duke Energy.
	INTEREST RATE RISK
	The Duke Energy Registrants are exposed to changes in interest rates as a result of their issuance or anticipated issuance of variable-rate and fixed-rate debt and commercial paper. Interest rate risk is managed by limiting variable-rate exposures to a percentage of total debt and by monitoring changes in interest rates. To manage risk associated with changes in interest rates, the Duke Energy Registrants may enter into interest rate swaps, U.S. Treasury lock agreements, and other financial contracts. In anticipation of certain fixed-rate debt issuances, a series of forward starting interest rate swaps may be executed to lock in components of current market interest rates. These instruments are later terminated prior to or upon the issuance of the corresponding debt. Pretax gains or losses recognized from inception to termination of the hedges are amortized as a component of interest expense over the life of the debt.
	Duke Energy has a combination foreign exchange, pay fixed-receive floating interest rate swap to fix the U.S. dollar equivalent payments on a floating-rate Chilean debt issue.
	The following tables show notional amounts for derivatives related to interest rate risk.
		December 31, 2014										December 31, 2013
	(in millions)	Duke				Duke			Duke			Duke				Duke
		Energy				Energy Florida			Energy			Energy				Energy
									Ohio							Ohio
	Cash flow hedges(a)	$	750			$	—		$	—		$	798			$	—
	Undesignated contracts	277				250			27			34				27
	Total notional amount	$	1,027			250			$	27		$	832			$	27
	(a)	Duke Energy includes amounts related to consolidated VIEs of $541 million at December 31, 2014 and $584 million at December 31, 2013.
	DUKE ENERGY
	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Designated as Hedging Instruments
	Commodity contracts
	Current liabilities: other	$	—			$	—		$	—		$	1
	Interest rate contracts
	Investments and other assets: other	10				—			27			—
	Current liabilities: other	—				13			—			18
	Deferred credits and other liabilities: other	—				29			—			4
	Total Derivatives Designated as Hedging Instruments	$	10			$	42		$	27		$	23
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Current assets: other	$	18			$	—		$	201		$	158
	Current assets: assets held for sale	15				—			—			—
	Investments and other assets: other	3				—			215			131
	Investments and other assets: assets held for sale	15				—			—			—
	Current liabilities: other	1				307			13			153
	Current liabilities: assets held for sale	174				253			—			—
	Deferred credits and other liabilities: other	2				91			5			166
	Deferred credits and other liabilities: assets held for sale	111				208			—			—
	Interest rate contracts
	Current assets: other	2				—			—			—
	Current liabilities: other	—				1			—			1
	Deferred credits and other liabilities: other	—				7			—			4
	Total Derivatives Not Designated as Hedging Instruments	341				867			434			613
	Total Derivatives	$	351			$	909		$	461		$	636
	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
	Derivative Assets
	31-Dec-14							31-Dec-13
(in millions)	Current(a)				Non-Current(b)			Current(e)			Non-Current(f)
Gross amounts recognized	$	210			$	136		$	214		$	233
Gross amounts offset	(153		)		(88		)	(179		)	(138		)
Net amount subject to master netting	57				48			35			95
Amounts not subject to master netting	—				5			—			14
Net amounts recognized on the Consolidated Balance Sheet	$	57			$	53		$	35		$	109
	Derivative Liabilities
	31-Dec-14							31-Dec-13
(in millions)	Current(c)				Non-Current(d)			Current(g)			Non-Current(h)
Gross amounts recognized	$	573			$	319		$	322		$	299
Gross amounts offset	(213		)		(173		)	(192		)	(155		)
Net amounts subject to master netting	360				146			130			144
Amounts not subject to master netting	1				16			4			11
Net amounts recognized on the Consolidated Balance Sheet	$	361			$	162		$	134		$	155
(a)    Included in Other and Assets Held for Sale within Current Assets on the Consolidated Balance Sheet.
(b)	Included in Other and Assets held for Sale within Investments and Other Assets on the Consolidated Balance Sheet.
(c)	Included in Other and Liabilities Associated with Assets Held for Sale within Current Liabilities on the Consolidated Balance Sheet.
(d)	Included in Other and Liabilities Associated with Assets Held for Sale within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
(e)	Included in Other within Current Assets on the Consolidated Balance Sheet.
(f)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
(g)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
(h)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
The following table shows the gains and losses recognized on cash flow hedges and the line items on the Consolidated Statements of Operations where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Pretax Gains (Losses) Recorded in AOCI
Interest rate contracts	$	(39	)		$	79		$	(23	)
Commodity contracts	—				1			1
Total Pretax Gains (Losses) Recorded in AOCI	$	(39	)		$	80		$	(22	)
Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
Interest rate contracts
Interest expense	(7		)		(2		)	2
There was no hedge ineffectiveness during the years ended December 31, 2014, 2013 and 2012, and no gains or losses were excluded from the assessment of hedge effectiveness during the same periods.
A $10 million pretax gain is expected to be recognized in earnings during the next 12 months as interest expense.
The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Recognized in Earnings
Commodity contracts
Revenue: Regulated electric	$	—			$	11		$	(23	)
Other income and expenses	—				—			(2		)
Fuel used in electric generation and purchased power-regulated	(44		)		(200		)	(194		)
Income (Loss) From Discontinued Operations	(729		)		(57		)	40
Interest rate contracts
Interest expense	(6		)		(18		)	(8		)
Total Pretax (Losses) Gains Recognized in Earnings	$	(779	)		$	(264	)	$	(187	)
Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
Commodity contracts
Regulatory assets	$	(268	)		$	10		$	(2	)
Regulatory liabilities	14				15			36
Interest rate contracts
Regulatory assets	—				55			10
Regulatory liabilities	2				—			—
Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(252	)		$	80		$	44
DUKE ENERGY CAROLINAS
The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
	December 31,
	2014							2013
(in millions)	Asset				Liability			Asset			Liability
Derivatives Not Designated as Hedging Instruments
Commodity contracts
Current liabilities: other	$	—			$	14		$	—		$	1
Deferred credits and other liabilities: other	—				5			—			1
Total Derivatives Not Designated as Hedging Instruments	—				19			—			2
Total Derivatives	$	—			$	19		$	—		$	2
The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
	Derivative Assets
	31-Dec-14							31-Dec-13
(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
Gross amounts recognized	$	—			$	—		$	—		$	—
Gross amounts offset	—				—			—			—
Net amount subject to master netting	—				—			—			—
Amounts not subject to master netting	—				—			—			—
Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	—		$	—
	Derivative Liabilities
	31-Dec-14							31-Dec-13
(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
Gross amounts recognized	$	14			$	5		$	—		$	—
Gross amounts offset	—				—			—			—
Net amount subject to master netting	14				5			—			—
Amounts not subject to master netting	—				—			1			1
Net amounts recognized on the Consolidated Balance Sheet	$	14			$	5		$	1		$	1
(a)	Included in Other within Current Assets on the Consolidated Balance Sheet.
(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
Interest rate contracts
Interest expense	$	(3	)		$	(3	)	$	(3	)
A $3 million pretax gain is expected to be recognized in earnings during the next 12 months as interest expense.
The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts not included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Recognized in Earnings
Commodity contracts
Revenue: Regulated electric	$	—			$	(12	)	$	(12	)
Total Pretax (Losses) Gains Recognized in Earnings	—				(12		)	(12		)
Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
Commodity contracts
Regulatory assets	$	(19	)		$	—		$	—
PROGRESS ENERGY
The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
	December 31,
	2014							2013
(in millions)	Asset				Liability			Asset			Liability
Derivatives Designated as Hedging Instruments
Commodity contracts
Current liabilities: other	$	—			$	1		$	—		$	1
Deferred credits and other liabilities: other	—				—			—			4
Total Derivatives Designated as Hedging Instruments	$	—			$	1		$	—		$	5
Derivatives Not Designated as Hedging Instruments
Commodity contracts
Current assets: other	$	—			$	—		$	3		$	2
Investments and other assets: other	—				—			2			1
Current liabilities: other	—				288			11			105
Deferred credits and other liabilities: other	—				80			4			91
Interest rate contracts
Current assets: other	2				—			—			—
Deferred credits and other liabilities: other	—				2			—			—
Total Derivatives Not Designated as Hedging Instruments	2				370			20			199
Total Derivatives	$	2			$	371		$	20		$	204
The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
	Derivative Assets
	31-Dec-14							31-Dec-13
(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
Gross amounts recognized	$	2			$	—		$	15		$	5
Gross amounts offset	(2		)		—			(13		)	(4		)
Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	2		$	1
	Derivative Liabilities
	31-Dec-14							31-Dec-13
(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
Gross amounts recognized	$	289			$	82		$	107		$	93
Gross amounts offset	(17		)		(8		)	(17		)	(10		)
Net amounts subject to master netting	272				74			90			83
Amounts not subject to master netting	—				—			—			4
Net amounts recognized on the Consolidated Balance Sheet	$	272			$	74		$	90		$	87
(a)    Included in Other within Current Assets on the Consolidated Balance Sheet.
(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income or Consolidated Balance Sheet where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Pretax Gains (Losses) Recorded in AOCI
Commodity contracts	$	—			$	1		$	1
Interest rate contracts	—				—			(11		)
Total Pretax Gains (Losses) Recorded in AOCI	$	—			$	1		$	(10	)
Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
Interest rate contracts
Interest expense	(13		)		—			(14		)
Location of Pretax Gains and (Losses) Reclassified from AOCI to Regulatory Assets or Liabilities(a)
Interest rate contracts
Regulatory assets	—				$	—		(159		)
(a)    Effective with the merger, Duke Energy Progress and Duke Energy Florida no longer designates interest rate derivatives for
regulated operations as cash flow hedges. As a result, the pretax losses on derivatives as of the date of the merger were reclassified from AOCI to regulatory assets.
There was no hedge ineffectiveness during the years ended December 31, 2014, 2013 and 2012, and no gains or losses have been excluded from the assessment of hedge effectiveness during the same periods.
A $13 million pretax loss is expected to be recognized in earnings during the next 12 months as interest expense.
The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Recognized in Earnings
Commodity contracts
Operating revenues	$	—			$	11		$	(11	)
Fuel used in electric generation and purchased power	(44		)		(200		)	(454		)
Other income and expenses, net	—				—			7
Interest rate contracts
Interest expense	(4		)		(17		)	(8		)
Total Pretax (Losses) Gains Recognized in Earnings	$	(48	)		$	(206	)	$	(466	)
Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
Commodity contracts
Regulatory assets	$	(233	)		$	10		$	(171	)
Regulatory liabilities	2				—			—
Interest rate contracts
Regulatory assets	2				18			6
Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(229	)		$	28		$	(165	)
DUKE ENERGY PROGRESS
The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown. Substantially all derivatives not designated as hedging instruments receive regulatory accounting treatment.
	December 31,
	2014							2013
(in millions)	Asset				Liability			Asset			Liability
Derivatives Designated as Hedging Instruments
Commodity contracts
Current liabilities: other	$	—			$	1		$	—		$	1
Total Derivatives Designated as Hedging Instruments	—				1			—			1
Derivatives Not Designated as Hedging Instruments
Commodity contracts
Investments and other assets: other	$	—			$	—		$	2		$	1
Current liabilities: other	—				108			2			40
Deferred credits and other liabilities: other	—				23			2			29
Total Derivatives Not Designated as Hedging Instruments	—				131			6			70
Total Derivatives	$	—			$	132		$	6		$	71
The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
	Derivative Assets
	31-Dec-14							31-Dec-13
(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
Gross amounts recognized	$	—			$	—		$	3		$	3
Gross amounts offset	—				—			(3		)	(3		)
Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	—		$	—
	Derivative Liabilities
	31-Dec-14							31-Dec-13
(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
Gross amounts recognized	$	109			$	23		$	41		$	30
Gross amounts offset	—				—			(3		)	(3		)
Net amounts recognized on the Consolidated Balance Sheet	$	109			$	23		$	38		$	27
(a)    Included in Other within Current Assets on the Consolidated Balance Sheet.
(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income or Consolidated Balance Sheets in which such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Pretax Gains (Losses) Recorded in AOCI
Interest rate contracts	$	—			$	—		$	(7	)
Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
Interest rate contracts
Interest expense	—				—			(5		)
Location of Pretax Gains and (Losses) Reclassified from AOCI to Regulatory Assets or Liabilities(a)
Interest rate contracts
Regulatory assets	—				$	—		(117		)
(a)	Effective with the merger, Duke Energy Progress no longer designates interest rate derivatives for regulated operations as cash flow hedges. As a result, the pretax losses on derivatives as of the date of the merger were reclassified from AOCI to Regulatory assets.
There was no hedge ineffectiveness during the years ended December 31, 2014, 2013 and 2012, and no gains or losses have been excluded from the assessment of hedge effectiveness during the same periods.
The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Recognized in Earnings
Commodity contracts
Operating revenues	$	—			$	11		$	(11	)
Fuel used in electric generation and purchased power	(15		)		(71		)	(115		)
Interest rate contracts
Interest expense	—				(13		)	(6		)
Total Pretax (Losses) Gains Recognized in Earnings	$	(15	)		$	(73	)	$	(132	)
Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
Commodity contracts
Regulatory assets	$	(82	)		$	(6	)	$	(55	)
Interest rate contracts
Regulatory assets	—				13			6
Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(82	)		$	7		$	(49	)
DUKE ENERGY FLORIDA
The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
	December 31,
	2014							2013
(in millions)	Asset				Liability			Asset			Liability
Derivatives Not Designated as Hedging Instruments
Commodity contracts
Current assets: other	$	—			$	—		$	3		$	2
Current liabilities: other	—				180			9			64
Deferred credits and other liabilities: other	—				57			2			63
Interest rate contracts
Current assets: other	2				—			—			—
Deferred credits and other liabilities: other	—				2			—			—
Total Derivatives Not Designated as Hedging Instruments	2				239			14			129
Total Derivatives	$	2			$	239		$	14		$	129
The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
	Derivative Assets
	31-Dec-14							31-Dec-13
(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
Gross amounts recognized	$	2			$	—		$	12		$	2
Gross amounts offset	(2		)		—			(10		)	(2		)
Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	2		$	—
	Derivative Liabilities
	31-Dec-14							31-Dec-13
(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
Gross amounts recognized	$	180			$	59		$	66		$	63
Gross amounts offset	(17		)		(8		)	(15		)	(7		)
Net amounts recognized on the Consolidated Balance Sheet	$	163			$	51		$	51		$	56
(a)	Included in Other within Current Assets on the Consolidated Balance Sheet.
(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income or Consolidated Balance Sheets in which such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Pretax Gains (Losses) Recorded in AOCI
Commodity contracts	$	—			$	1		$	1
Interest rate contracts	—				—			(2		)
Total Pretax Gains (Losses) Recorded in AOCI	$	—			$	1		$	(1	)
Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
Interest rate contracts
Interest expense	(2		)		—			(2		)
Location of Pretax Gains and (Losses) Reclassified from AOCI to Regulatory Assets(a)
Interest rate contracts
Regulatory assets	—				$	—		(42		)
(a)	Effective with the merger, Duke Energy Florida no longer designates interest rate derivatives for regulated operations as cash flow hedges. As a result, the pretax losses on derivatives as of the date of the merger were reclassified from AOCI to Regulatory assets.
The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Recognized in Earnings
Commodity contracts
Fuel used in electric generation and purchased power	$	(29	)		$	(129	)	$	(339	)
Interest rate contracts
Interest expense	(4		)		(5		)	(2		)
Total Pretax (Losses) Gains Recognized in Earnings	$	(33	)		$	(134	)	$	(341	)
Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
Commodity contracts
Regulatory assets	$	(151	)		$	16		$	(116	)
Interest rate contracts
Regulatory assets	2				5			—
Regulatory liabilities	2				—			—
Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(147	)		$	21		$	(116	)
DUKE ENERGY OHIO
The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
	December 31,
	2014							2013
(in millions)	Asset				Liability			Asset			Liability
Derivatives Not Designated as Hedging Instruments
Commodity contracts
Current assets: other	$	1			$	—		$	186		$	163
Current assets: assets held for sale	28				4			—			—
Investments and other assets: other	—				—			202			130
Investments and other assets: assets held for sale	26				4			—			—
Current liabilities: other	—				—			1			36
Current liabilities: assets held for sale	175				252			—			—
Deferred credits and other liabilities: other	—				—			2			56
Deferred credits and other liabilities: assets held for sale	111				207			—			—
Interest rate contracts
Current liabilities: other	—				1			—			1
Deferred credits and other liabilities: other	—				5			—			4
Total Derivatives Not Designated as Hedging Instruments	341				473			391			390
Total Derivatives	$	341			$	473		$	391		$	390
The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
	Derivative Assets
	31-Dec-14							31-Dec-13
(in millions)	Current(a)				Non-Current(b)			Current(e)			Non-Current(f)
Gross amounts recognized	$	204			$	137		$	186		$	205
Gross amounts offset	(179		)		(114		)	(165		)	(132		)
Net amounts recognized on the Consolidated Balance Sheet	$	25			$	23		$	21		$	73
	Derivative Liabilities
	31-Dec-14							31-Dec-13
(in millions)	Current(c)				Non-Current(d)			Current(g)			Non-Current(h)
Gross amounts recognized	$	257			$	216		$	199		$	186
Gross amounts offset	(222		)		(193		)	(173		)	(143		)
Net amounts subject to master netting	35				23			26			43
Amounts not subject to master netting	—				—			1			4
Net amounts recognized on the Consolidated Balance Sheet	$	35			$	23		$	27		$	47
(a)    Included in Other and Assets Held for Sale within Current Assets on the Consolidated Balance Sheet.
(b)	Included in Other and Assets held for Sale within Investments and Other Assets on the Consolidated Balance Sheet.
(c)	Included in Other and Liabilities Associated with Assets Held for Sale within Current Liabilities on the Consolidated Balance Sheet.
(d)	Included in Other and Liabilities Associated with Assets Held for Sale within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
(e)	Included in Other within Current Assets on the Consolidated Balance Sheet.
(f)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
(g)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
(h)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Recognized in Earnings
Commodity contracts
Income (Loss) from discontinued operations	(758		)		(56		)	78
Interest rate contracts
Interest expense	(1		)		(1		)	(1		)
Total Pretax (Losses) Gains Recognized in Earnings	$	(759	)		$	(57	)	$	77
Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
Commodity contracts
Regulatory assets	$	1			$	—		$	2
Regulatory liabilities	5				—			(1		)
Interest rate contracts
Regulatory assets	(2		)		4			—
Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	4			$	4		$	1
DUKE ENERGY INDIANA
The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
	December 31,
	2014							2013
(in millions)	Asset				Liability			Asset			Liability
Derivatives Not Designated as Hedging Instruments
Commodity contracts
Current Assets: Other	$	14			$	—		$	12		$	—
Total Derivatives Not Designated as Hedging Instruments	14				—			12			—
Total Derivatives	$	14			$	—		$	12		$	—
The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
	Derivative Assets
	31-Dec-14							31-Dec-13
(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
Gross amounts recognized	$	14			$	—		$	12		$	—
Gross amounts offset	—				—			(1		)	—
Net amounts recognized on the Consolidated Balance Sheet	$	14			$	—		$	11		$	—
	Derivative Liabilities
	31-Dec-14							31-Dec-13
(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
Gross amounts recognized	$	—			$	—		$	—		$	—
Gross amounts offset	—				—			—			—
Net amount subject to master netting	—				—			—			—
Amounts not subject to master netting	—				—			—			—
Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	—		$	—
(a)	Included in Other within Current Assets on the Consolidated Balance Sheet.
(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
Interest rate contracts
Interest expense	$	—			$	3		$	3
The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
	Years Ended December 31,
(in millions)	2014				2013			2012
Location of Pretax Gains and (Losses) Recognized in Earnings
Commodity contracts
Revenue: Regulated electric	$	—			$	1		$	—
Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
Commodity contracts
Regulatory assets	$	(16	)		$	—		$	2
Regulatory liabilities	9				16			35
Interest rate contracts
Regulatory assets	—				34			4
Regulatory liabilities	—				—			—
Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(7	)		$	50		$	41
CREDIT RISK
Certain derivative contracts contain contingent credit features. These features may include (i) material adverse change clauses or payment acceleration clauses that could result in immediate payments or (ii) the posting of letters of credit or termination of the derivative contract before maturity if specific events occur, such as a credit rating downgrade below investment grade.
The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk related payment provisions.
	December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas			Progress Energy			Duke Energy Progress				Duke Energy Florida			Duke Energy Ohio
Aggregate fair value amounts of derivative instruments in a net liability position	$	845			$	19		$	370		$	131			$	239		$	456
Fair value of collateral already posted	209				—			23			—				23			186
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	407				19			347			131				216			41
	December 31, 2013
(in millions)	Duke Energy				Progress Energy			Duke Energy Progress			Duke Energy Florida				Duke Energy Ohio
Aggregate fair value amounts of derivative instruments in a net liability position	$	525			$	168		$	60		$	108			$	355
Fair value of collateral already posted	135				10			—			10				125
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	205				158			60			98				47
The Duke Energy Registrants have elected to offset cash collateral and fair values of derivatives. For amounts to be netted, the derivative must be executed with the same counterparty under the same master netting agreement. Amounts disclosed below represent the receivables related to the right to reclaim cash collateral and payables related to the obligation to return cash collateral under master netting arrangements.
	December 31,
	2014							2013
(in millions)	Receivables				Payables			Receivables			Payables
Duke Energy
Amounts offset against net derivative positions	$	145			$	—		$	30		$	—
Amounts not offset against net derivative positions	64				—			122			—
Progress Energy
Amounts offset against net derivative positions	23				—			10			—
Duke Energy Florida
Amounts offset against net derivative positions	23				—			10			—
Duke Energy Ohio
Amounts offset against net derivative positions	122				—			19			—
Amounts not offset against net derivative positions	64				—			115			—
Duke Energy Indiana
Amounts offset against net derivative positions	—				—			—			1
Amounts not offset against net derivative positions	—				—			1			—

Investments_in_Debt_and_Equity

Investments in Debt and Equity Securities	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investments in Debt and Equity Securities	INVESTMENTS IN DEBT AND EQUITY SECURITIES
	The Duke Energy Registrants classify their investments in debt and equity securities as either trading or available-for-sale.
	TRADING SECURITIES
	Investments in debt and equity securities held in grantor trusts associated with certain deferred compensation plans and certain other investments are classified as trading securities. The fair value of these investments was $7 million as of December 31, 2014 and $18 million as of December 31, 2013.
	AVAILABLE-FOR-SALE SECURITIES
	All other investments in debt and equity securities are classified as available-for-sale securities.
	Duke Energy’s available-for-sale securities are primarily comprised of investments held in (i) the NDTF at Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, (ii) grantor trusts at Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana related to OPEB plans, (iii) Duke Energy’s captive insurance investment portfolio, and (iv) Duke Energy’s foreign operations investment portfolio.
	Duke Energy holds corporate debt securities that were purchased using excess cash from its foreign operations. These investments are either classified as Cash and cash equivalents or Short-term investments on the Consolidated Balance Sheets based on maturity date and are available for current operations of Duke Energy’s foreign business. The fair value of these investments classified as Short-term investments was $44 million as of December 31, 2013.
	Duke Energy classifies all other investments in debt and equity securities as long-term, unless otherwise noted.
	Investment Trusts
	The investments within the NDTF at Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida and the Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana grantor trusts (Investment Trusts) are managed by independent investment managers with discretion to buy, sell, and invest pursuant to the objectives set forth by the trust agreements. The Duke Energy Registrants have limited oversight of the day-to-day management of these investments. As a result, the ability to hold investments in unrealized loss positions is outside the control of the Duke Energy Registrants. Accordingly, all unrealized losses associated with debt and equity securities within the Investment Trusts are considered other-than-temporary impairments and are recognized immediately. Pursuant to regulatory accounting, realized and unrealized gains and losses associated with investments within the Investment Trusts are deferred as a regulatory asset or liability. As a result, there is no immediate impact on earnings of the Duke Energy Registrants.
	Other Available-for-Sale Securities
	Unrealized gains and losses on all other available-for-sale securities are included in other comprehensive income until realized, unless it is determined the carrying value of an investment is other-than-temporarily impaired. If an other-than-temporary impairment exists, the unrealized loss is included in earnings based on the criteria discussed below.
	The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value should be considered other-than-temporary. Criteria used to evaluate whether an impairment associated with equity securities is other-than-temporary includes, but is not limited to, (i) the length of time over which the market value has been lower than the cost basis of the investment, (ii) the percentage decline compared to the cost of the investment, and (iii) management’s intent and ability to retain its investment for a period of time sufficient to allow for any anticipated recovery in market value. If a decline in fair value is determined to be other-than-temporary, the investment is written down to its fair value through a charge to earnings.
	If the entity does not have an intent to sell a debt security and it is not more likely than not management will be required to sell the debt security before the recovery of its cost basis, the impairment write-down to fair value would be recorded as a component of other comprehensive income, except for when it is determined a credit loss exists. In determining whether a credit loss exists, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than the amortized cost basis, (ii) changes in the financial condition of the issuer of the security, or in the case of an asset backed security, the financial condition of the underlying loan obligors, (iii) consideration of underlying collateral and guarantees of amounts by government entities, (iv) ability of the issuer of the security to make scheduled interest or principal payments, and (v) any changes to the rating of the security by rating agencies. If a credit loss exists, the amount of impairment write-down to fair value is split between credit loss and other factors. The amount related to credit loss is recognized in earnings. The amount related to other factors is recognized in other comprehensive income. There were no credit losses as of December 31, 2014 and 2013. There were no other-than-temporary impairments for debt or equity securities as of December 31, 2014 and 2013.
	DUKE ENERGY
	The following table presents the estimated fair value of investments in available-for-sale securities.
		31-Dec-14						31-Dec-13
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	NDTF
	Cash and cash equivalents	$	—	$	—	$	136	$	—	$	—	$	110
	Equity securities	1,926		29		3,650		1,813		10		3,579
	Corporate debt securities	14		2		454		8		6		400
	Municipal bonds	5		—		184		2		6		160
	U.S. government bonds	19		2		978		7		12		730
	Other debt securities	1		2		147		22		2		154
	Total NDTF	1,965		35		5,549		1,852		36		5,133
	Other Investments
	Cash and cash equivalents	—		—		15		—		—		21
	Equity securities	34		—		96		29		—		91
	Corporate debt securities	1		1		58		1		1		99
	Municipal bonds	3		1		76		2		2		79
	U.S. government bonds	—		—		27		—		—		17
	Other debt securities	1		1		80		—		8		111
	Total Other Investments(a)	39		3		352		32		11		418
	Total Investments	$	2,004	$	38	$	5,901	$	1,884	$	47	$	5,551
	(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
	The table below summarizes the maturity date for debt securities.
	(in millions)	December 31, 2014
	Due in one year or less	178
	Due after one through five years	571
	Due after five through 10 years	464
	Due after 10 years	791
	Total	2,004
	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Realized gains	$	271	$	209	$	117
	Realized losses	105		65		19
	DUKE ENERGY CAROLINAS
	The following table presents the estimated fair value of investments in available-for-sale securities.
		December 31, 2014						December 31, 2013
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	NDTF
	Cash and cash equivalents	$	—	$	—	$	51	$	—	$	—	$	42
	Equity securities	1,102		17		2,162		974		6		1,964
	Corporate debt securities	8		2		316		5		5		274
	Municipal bonds	1		—		62		—		2		54
	U.S. government bonds	7		1		308		3		7		354
	Other debt securities	1		2		133		22		2		146
	Total NDTF	1,119		22		3,032		1,004		22		2,834
	Other Investments
	Other debt securities	—		1		3		—		1		3
	Total Other Investments(a)	—		1		3		—		1		3
Total Investments	$	1,119	$	23	$	3,035	$	1,004	$	23	$	2,837
(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
The table below summarizes the maturity date for debt securities.
(in millions)	December 31, 2014
Due in one year or less	$	1
Due after one through five years	155
Due after five through 10 years	257
Due after 10 years	409
Total	$	822
Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	109	$	115	$	89
Realized losses	93		12		6
PROGRESS ENERGY
The following table presents the estimated fair value of investments in available-for-sale securities.
	31-Dec-14						31-Dec-13
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	85	$	—	$	—	$	68
Equity securities	824		12		1,488		839		4		1,615
Corporate debt securities	6		—		138		3		1		126
Municipal bonds	4		—		122		2		4		106
U.S. government bonds	12		1		670		4		5		376
Other debt securities	—		—		14		—		—		8
Total NDTF	846		13		2,517		848		14		2,299
Other Investments
Cash and cash equivalents	—		—		15		—		—		20
Municipal bonds	3		—		43		1		—		39
Total Other Investments(a)	3		—		58		1		—		59
Total Investments	$	849	$	13	$	2,575	$	849	$	14	$	2,358
(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
The table below summarizes the maturity date for debt securities.
(in millions)	December 31, 2014
Due in one year or less	$	161
Due after one through five years	350
Due after five through 10 years	157
Due after 10 years	319
Total	$	987
Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	157	$	90	$	34
Realized losses	11		46		18
DUKE ENERGY PROGRESS
The following table presents the estimated fair value of investments in available-for-sale securities.
	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	48
Equity securities	612		10		1,171		535		3		1,069
Corporate debt securities	5		—		97		3		1		80
Municipal bonds	4		—		120		2		4		104
U.S. government bonds	9		1		265		4		3		232
Other debt securities	—		—		8		—		—		5
Total NDTF	630		11		1,711		544		11		1,538
Other Investments
Cash and cash equivalents	—		—		—		—		—		2
Total Other Investments(a)	—		—		—		—		—		2
Total Investments	$	630	$	11	$	1,711	$	544	$	11	$	1,540
(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
The table below summarizes the maturity date for debt securities.
(in millions)	December 31, 2014
Due in one year or less	$	14
Due after one through five years	140
Due after five through 10 years	109
Due after 10 years	227
Total	$	490
Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	19	$	58	$	21
Realized losses	5		26		8
DUKE ENERGY FLORIDA
The following table presents the estimated fair value of investments in available-for-sale securities.
	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
NDTF
Cash and cash equivalents	$	—	$	—	$	35	$	—	$	—	$	20
Equity securities	212		2		317		304		1		546
Corporate debt securities	1		—		41		—		—		46
Municipal bonds	—		—		2		—		—		2
U.S. government bonds	3		—		405		—		2		144
Other debt securities	—		—		6		—		—		3
Total NDTF	216		2		806		304		3		761
Other Investments
Cash and cash equivalents	—		—		1		—		—		3
Municipal bonds	3		—		43		1		—		39
Total Other Investments(a)	3		—		44		1		—		42
Total Investments	$	219	$	2	$	850	$	305	$	3	$	803
(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
The table below summarizes the maturity date for debt securities.
(in millions)	December 31, 2014
Due in one year or less	$	147
Due after one through five years	210
Due after five through 10 years	48
Due after 10 years	92
Total	$	497
Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
	Years Ended December 31,
(in millions)	2014		2013		2012
Realized gains	$	138	$	32	$	13
Realized losses	5		20		9
DUKE ENERGY INDIANA
The following table presents the estimated fair value of investments in available-for-sale securities.
	December 31, 2014						December 31, 2013
(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
Other Investments
Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
Equity securities	28		—		71		24		—		65
Municipal bonds	—		1		30		—		1		28
Total Other Investments(a)	28		1		101		24		1		94
Total Investments	$	28	$	1	$	101	$	24	$	1	$	94
(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
The table below summarizes the maturity date for debt securities.
(in millions)	December 31, 2014
Due in one year or less	$	1
Due after one through five years	17
Due after five through 10 years	8
Due after 10 years	4
Total	$	30
Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were insignificant for the years ended December 31, 2014, 2013 and 2012.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS
	Fair value is the exchange price to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. The fair value definition focuses on an exit price versus the acquisition cost. Fair value measurements use market data or assumptions market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs may be readily observable, corroborated by market data, or generally unobservable. Valuation techniques maximize the use of observable inputs and minimize use of unobservable inputs. A midmarket pricing convention (the midpoint price between bid and ask prices) is permitted for use as a practical expedient.
	Fair value measurements are classified in three levels based on the fair value hierarchy:
	Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. An active market is one in which transactions for an asset or liability occur with sufficient frequency and volume to provide ongoing pricing information.
	Level 2 – A fair value measurement utilizing inputs other than quoted prices included in Level 1 that are observable, either directly or indirectly, for an asset or liability. Inputs include (i) quoted prices for similar assets or liabilities in active markets, (ii) quoted prices for identical or similar assets or liabilities in markets that are not active, (iii) and inputs other than quoted market prices that are observable for the asset or liability, such as interest rate curves and yield curves observable at commonly quoted intervals, volatilities and credit spreads. A Level 2 measurement cannot have more than an insignificant portion of its valuation based on unobservable inputs. Instruments in this category include non-exchange-traded derivatives, such as over-the-counter forwards, swaps and options; certain marketable debt securities; and financial instruments traded in less than active markets.
	Level 3 – Any fair value measurement which includes unobservable inputs for more than an insignificant portion of the valuation. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value. Level 3 measurements may include longer-term instruments that extend into periods in which observable inputs are not available.
	The fair value accounting guidance permits entities to elect to measure certain financial instruments that are not required to be accounted for at fair value, such as equity method investments or the company’s own debt, at fair value. The Duke Energy Registrants have not elected to record any of these items at fair value.
	Transfers between levels represent assets or liabilities that were previously (i) categorized at a higher level for which the inputs to the estimate became less observable or (ii) classified at a lower level for which the inputs became more observable during the period. The Duke Energy Registrant’s policy is to recognize transfers between levels of the fair value hierarchy at the end of the period. There were no transfers between Levels 1 and 2 during the years ended December 31, 2014, 2013 and 2012. Transfers out of Level 3 during the year ended December 31, 2014 are the result of forward commodity prices becoming observable due to the passage of time.
	Valuation methods of the primary fair value measurements disclosed below are as follows.
	Investments in equity securities
	The majority of investments in equity securities are valued using Level 1 measurements. Investments in equity securities are typically valued at the closing price in the principal active market as of the last business day of the quarter. Principal active markets for equity prices include published exchanges such as NASDAQ and New York Stock Exchange (NYSE). Foreign equity prices are translated from their trading currency using the currency exchange rate in effect at the close of the principal active market. There was no after-hours market activity that was required to be reflected in the reported fair value measurements. Investments in equity securities that are Level 2 or 3 are typically ownership interests in commingled investment funds.
	Investments in debt securities
	Most investments in debt securities are valued using Level 2 measurements because the valuations use interest rate curves and credit spreads applied to the terms of the debt instrument (maturity and coupon interest rate) and consider the counterparty credit rating. If the market for a particular fixed income security is relatively inactive or illiquid, the measurement is Level 3.
	Commodity derivatives
	Commodity derivatives with clearinghouses are classified as Level 1. Other commodity derivatives are primarily fair valued using internally developed discounted cash flow models which incorporate forward price, adjustments for liquidity (bid-ask spread) and credit or non-performance risk (after reflecting credit enhancements such as collateral), and are discounted to present value. Pricing inputs are derived from published exchange transaction prices and other observable data sources. In the absence of an active market, the last available price may be used. If forward price curves are not observable for the full term of the contract and the unobservable period had more than an insignificant impact on the valuation, the commodity derivative is classified as Level 3. In isolation, increases (decreases) in natural gas forward prices result in favorable (unfavorable) fair value adjustments for gas purchase contracts; and increases (decreases) in electricity forward prices result in unfavorable (favorable) fair value adjustments for electricity sales contracts. Duke Energy regularly evaluates and validates pricing inputs used to estimate fair value of gas commodity contracts by a market participant price verification procedure. This procedure provides a comparison of internal forward commodity curves to market participant generated curves.
	Interest rate derivatives
	Most over-the-counter interest rate contract derivatives are valued using financial models which utilize observable inputs for similar instruments and are classified as Level 2. Inputs include forward interest rate curves, notional amounts, interest rates and credit quality of the counterparties.
	Goodwill and Long-Lived Assets and Assets Held for Sale
	See Note 11 for a discussion of the valuation of goodwill and long-lived assets and Note 2 related to the assets and related liabilities of the Disposal Group classified as held for sale.
	DUKE ENERGY
	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	3,650			$	3,493			$	6		$	151
	Nuclear decommissioning trust fund debt securities	1,899				648				1,251			—
	Other trading and available-for-sale equity securities	96				96				—			—
	Other trading and available-for-sale debt securities	263				41				217			5
	Derivative assets	110				49				24			37
	Total assets	6,018				4,327				1,498			193
	Derivative liabilities	(668		)		(162		)		(468		)	(38		)
	Net assets	$	5,350			$	4,165			$	1,030		$	155
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	3,579			$	3,495			$	57		$	27
	Nuclear decommissioning trust fund debt securities	1,553				402				1,100			51
	Other trading and available-for-sale equity securities	102				91				11			—
	Other trading and available-for-sale debt securities	333				36				277			20
	Derivative assets	145				33				70			42
	Total assets	5,712				4,057				1,515			140
	Derivative liabilities	(321		)		11				(303		)	(29		)
	Net assets	$	5,391			$	4,068			$	1,212		$	111
	The following tables provide reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Amounts included in earnings for derivatives are primarily included in Operating Revenues.
		December 31, 2014
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	98			$	13			$	111
	Total pretax realized or unrealized gains (losses) included in earnings	—				(7		)		(7		)
	Purchases, sales, issuances and settlements:
	Purchases	34				50				84
	Sales	(58		)		—				(58		)
	Settlements	—				(54		)		(54		)
	Transfers into Level 3	68				6				74
	Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	14				(9		)		5
	Balance at end of period	$	156			$	(1	)		$	155
	Pretax amounts included in the Consolidated Statements of Comprehensive Income related to Level 3 measurements outstanding	$	—			$	(14	)		$	(14	)
		December 31, 2013
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	98			$	(85	)		$	13
	Total pretax realized or unrealized gains (losses) included in earnings	—				(42		)		(42		)
	Purchases, sales, issuances and settlements:
	Purchases	9				21				30
	Sales	(6		)		—				(6		)
	Issuances	—				11				11
	Settlements	(9		)		25				16
	Transfers into Level 3	—				86				86
Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	6				(3		)		3
Balance at end of period	$	98			$	13			$	111
	December 31, 2012
(in millions)	Investments				Derivatives (net)				Total
Balance at beginning of period	$	124			$	(39	)		$	85
Amounts acquired in Progress Energy Merger	—				(30		)		(30		)
Total pretax realized or unrealized gains (losses) included in earnings	—				8				8
Total pretax gains included in other comprehensive income	13				—				13
Purchases, sales, issuances and settlements:
Purchases	14				22				36
Sales	(2		)		—				(2		)
Issuances	—				(15		)		(15		)
Settlements	(55		)		(32		)		(87		)
Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	4				1				5
Balance at end of period	$	98			$	(85	)		$	13
DUKE ENERGY CAROLINAS
The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
	December 31, 2014
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	2,162			$	2,005			$	6		$	151
Nuclear decommissioning trust fund debt securities	870				138				732			—
Other trading and available-for-sale debt securities	3				—				—			3
Total assets	3,035				2,143				738			154
Derivative liabilities	(19		)		—				(19		)	—
Net assets	$	3,016			$	2,143			$	719		$	154
	December 31, 2013
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	1,964			$	1,879			$	58		$	27
Nuclear decommissioning trust fund debt securities	870				168				651			51
Other trading and available-for-sale debt securities	3				—				—			3
Total assets	2,837				2,047				709			81
Derivative liabilities	(2		)		—				—			(2		)
Net assets	$	2,835			$	2,047			$	709		$	79
The following tables provide a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
	December 31, 2014
(in millions)	Investments				Derivatives (net)				Total
Balance at beginning of period	$	81			$	(2	)		$	79
Purchases, sales, issuances and settlements:
Purchases	34				—				34
Sales	(43		)		—				(43		)
Settlements	—				2				2
Transfers into Level 3	68				—				68
Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	14				—				14
Balance at end of period	$	154			$	—			$	154
	December 31, 2013
(in millions)	Investments				Derivatives (net)				Total
Balance at beginning of period	$	72			$	(12	)		$	60
Purchases, sales, issuances and settlements:
Purchases	9				—				9
Issuances	(6		)		—				(6		)
Settlements	—				10				10
Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	6				—				6
Balance at end of period	$	81			$	(2	)		$	79
	December 31, 2012
(in millions)	Investments				Derivatives (net)				Total
Balance at beginning of period	$	65			$	—			$	65
Total pretax gains included in other comprehensive income	2				—				2
Purchases, sales, issuances and settlements:
Purchases	14				—				14
Sales	—				(14		)		(14		)
Issuances	(2		)		—				(2		)
Settlements	(11		)		2				(9		)
Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	4				—				4
Balance at end of period	$	72			$	(12	)		$	60
PROGRESS ENERGY
The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis end on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
	December 31, 2014
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	1,488			$	1,488			$	—		$	—
Nuclear decommissioning trust fund debt securities	1,029				510				519			—
Other trading and available-for-sale debt securities	58				15				43			—
Derivative assets	4				—				4			—
Total assets	2,579				2,013				566			—
Derivative liabilities	(373		)		—				(373		)	—
Net assets	$	2,206			$	2,013			$	193		$	—
	December 31, 2013
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	1,615			$	1,615			$	—		$	—
Nuclear decommissioning trust fund debt securities	677				233				444			—
Other trading and available-for-sale debt securities	58				19				39			—
Derivative assets	3				—				3			—
Total assets	2,353				1,867				486			—
Derivative liabilities	(187		)		—				(187		)	—
Net assets	$	2,166			$	1,867			$	299		$	—
The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
	Derivatives (net)
	Years Ended December 31,
(in millions)	2014				2013				2012
Balance at beginning of period	$	—			$	(38	)		$	(24	)
Total pretax realized or unrealized gains included in earnings	—				—				1
Purchases, sales, issuances and settlements:
Issuances	—				10				(16		)
Settlements	—				—				4
Transfers into Level 3	—				34				—
Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	—				(6		)		(3		)
Balance at end of period	$	—			$	—			$	(38	)
DUKE ENERGY PROGRESS
The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
	December 31, 2014
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	1,171			$	1,171			$	—		$	—
Nuclear decommissioning trust fund debt securities and other	540				151				389			—
Total assets	1,711				1,322				389			—
Derivative liabilities	(132		)		—				(132		)	—
Net assets	$	1,579			$	1,322			$	257		$	—
	December 31, 2013
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	1,069			$	1,069			$	—		$	—
Nuclear decommissioning trust fund debt securities and other	470				137				333			—
Other trading and available-for-sale debt securities and other	3				3				—			—
Derivative assets	1				—				1			—
Total assets	1,543				1,209				334			—
Derivative liabilities	(66		)		—				(66		)	—
Net assets	$	1,477			$	1,209			$	268		$	—
The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
	Derivatives (net)
	Years Ended December 31,
(in millions)	2014				2013				2012
Balance at beginning of period	$	—			$	(38	)		$	(24	)
Total pretax realized or unrealized gains included in earnings	—				—				1
Purchases, sales, issuances and settlements:
Issuances	—				10				(16		)
Settlements	—				—				4
Transfers into Level 3	—				34				—
Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	—				(6		)		(3		)
Balance at end of period	$	—			$	—			$	(38	)
DUKE ENERGY FLORIDA
The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
	December 31, 2014
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	317			$	317			$	—		$	—
Nuclear decommissioning trust fund debt securities and other	489				359				130			—
Other trading and available-for-sale debt securities and other	44				—				44			—
Derivative assets	4				—				4			—
Total assets	854				676				178			—
Derivative liabilities	(241		)		—				(241		)	—
Net assets (liabilities)	$	613			$	676			$	(63	)	$	—
	December 31, 2013
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Nuclear decommissioning trust fund equity securities	$	546			$	546			$	—		$	—
Nuclear decommissioning trust fund debt securities and other	214				96				118			—
Other trading and available-for-sale debt securities and other	40				2				38			—
Derivative assets	1				—				1			—
Total assets	801				644				157			—
Derivative liabilities	(116		)		—				(116		)	—
Net assets	$	685			$	644			$	41		$	—
DUKE ENERGY OHIO
The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which are disclosed in Note 14.
	December 31, 2014
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Derivative assets	$	49			$	20			$	9		$	20
Derivative liabilities	(181		)		(117		)		(26		)	(38		)
Net assets (liabilities)	$	(132	)		$	(97	)		$	(17	)	$	(18	)
	December 31, 2013
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Derivative assets	$	96			$	50			$	21		$	25
Derivative liabilities	(95		)		(1		)		(65		)	(29		)
Net assets (liabilities)	$	1			$	49			$	(44	)	$	(4	)
The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
	Derivatives (net)
	Years Ended December 31,
(in millions)	2014				2013				2012
Balance at beginning of period	$	(4	)		$	(6	)		$	(3	)
Total pretax realized or unrealized gains included in earnings	(9		)		(42		)		(3		)
Purchases, sales, issuances and settlements:
Purchases	1				1				—
Settlements	(13		)		—				1
Transfers into Level 3	6				43				—
Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	1				—				(1		)
Balance at end of period	$	(18	)		$	(4	)		$	(6	)
DUKE ENERGY INDIANA
The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
	December 31, 2014
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Available-for-sale equity securities	$	71			$	71			$	—		$	—
Available-for-sale debt securities	30				—				30			—
Derivative assets	14				—				—			14
Net assets (liabilities)	$	115			$	71			$	30		$	14
	December 31, 2013
(in millions)	Total Fair Value				Level 1				Level 2			Level 3
Available-for-sale equity securities	$	65			$	65			$	—		$	—
Available-for-sale debt securities	29				—				29			—
Derivative assets	12				—				—			12
Net assets (liabilities)	$	106			$	65			$	29		$	12
The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
	Derivatives (net)
	Years Ended December 31,
(in millions)	2014				2013				2012
Balance at beginning of period	$	12			$	10			$	4
Total pretax realized or unrealized gains included in earnings	3				8				36
Purchases, sales, issuances and settlements:
Purchases	49				20				—
Issuances	—				—				22
Settlements	(41		)		(30		)		(52		)
Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	(9		)		4				—
Balance at end of period	$	14			$	12			$	10
QUANTITATIVE INFORMATION ABOUT UNOBSERVABLE INPUTS
The following table includes quantitative information about the Duke Energy Registrants' derivatives classified as Level 3.
	December 31, 2014
Investment Type	Fair Value			Valuation Technique	Unobservable Input	Range
	(in millions)
Duke Energy
Natural gas contracts	$	(5	)	Discounted cash flow	Forward natural gas curves - price per Million British Thermal Unit (MMBtu)	$	2.12		-	4.35
Financial transmission rights (FTRs)	14			RTO auction pricing	FTR price - per Megawatt-Hour (MWh)	(1.92		)	-	9.86
Electricity contracts	(1		)	Discounted cash flow	Forward electricity curves - price per MWh	25.16			-	51.75
Commodity capacity option contracts	2			Discounted cash flow	Forward capacity option curves  - price per MW day	21			-	109
Reserves	(11		)		Bid-ask spreads, implied volatility, probability of default
Total Level 3 derivatives	$	(1	)
Duke Energy Ohio
Electricity contracts	$	(6	)	Discounted cash flow	Forward electricity curves - price per MWh	$	25.25		-	51.75
Natural gas contracts	(5		)	Discounted cash flow	Forward natural gas curves - price per MMBtu	2.12			-	4.35
Reserves	(7		)		Bid-ask spreads, implied volatility, probability of default
Total Level 3 derivatives	$	(18	)
Duke Energy Indiana
FTRs	$	14		RTO auction pricing	FTR price - per MWh	$	(1.92	)	-	9.86
	December 31, 2013
Investment Type	Fair Value			Valuation Technique	Unobservable Input	Range
	(in millions)
Duke Energy
Natural gas contracts	$	(2	)	Discounted cash flow	Forward natural gas curves - price per MMBtu	$	3.07		-	5.37
FERC mitigation power sale agreements	(2		)	Discounted cash flow	Forward electricity curves - price per MWh	25.79			-	52.38
FTRs	12			RTO auction pricing	FTR price - per MWh	(0.30		)	-	13.8
Electricity contracts	23			Discounted cash flow	Forward electricity curves - price per MWh	20.77			-	58.9
Commodity capacity option contracts	4			Discounted cash flow	Forward capacity option curves  - price per MW day	30.4			-	165.1
Reserves	(22		)		Bid-ask spreads, implied volatility, probability of default
Total Level 3 derivatives	$	13
Duke Energy Carolinas
FERC mitigation power sale agreements	$	(2	)	Discounted cash flow	Forward electricity curves - price per MWh	$	25.79		-	52.38
Duke Energy Ohio
Electricity contracts	$	18		Discounted cash flow	Forward electricity curves - price per MWh	$	20.77		-	58.9
Natural gas contracts	(2		)	Discounted cash flow	Forward natural gas curves - price per MMBtu	3.07			-	5.37
Reserves	(20		)		Bid-ask spreads, implied volatility, probability of default
Total Level 3 derivatives	$	(4	)
Duke Energy Indiana
FTRs	$	12		RTO auction pricing	FTR price - per MWh	$	(0.30	)	-	13.8
OTHER FAIR VALUE DISCLOSURES
The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements.
	December 31, 2014								December 31, 2013
(in millions)	Book Value				Fair Value				Book Value			Fair Value
Duke Energy	$	40,020			$	44,566			$	40,256		$	42,592
Duke Energy Carolinas	8,391				9,626				8,436			9,123
Progress Energy	14,754				16,951				14,115			15,234
Duke Energy Progress	6,201				6,696				5,235			5,323
Duke Energy Florida	4,860				5,767				4,886			5,408
Duke Energy Ohio	1,766				1,970				2,188			2,237
Duke Energy Indiana	3,791				4,456				3,796			4,171
At both December 31, 2014 and December 31, 2013, fair value of cash and cash equivalents, accounts and notes receivable, accounts payable, notes payable and commercial paper, and non-recourse notes payable of variable interest entities are not materially different from their carrying amounts because of the short-term nature of these instruments and/or because the stated rates approximate market rates.

Variable_Interest_Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2014
Variable Interest Entities [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES
	A VIE is an entity that is evaluated for consolidation using more than a simple analysis of voting control. The analysis to determine whether an entity is a VIE considers contracts with an entity, credit support for an entity, the adequacy of the equity investment of an entity, and the relationship of voting power to the amount of equity invested in an entity. This analysis is performed either upon the creation of a legal entity or upon the occurrence of an event requiring reevaluation, such as a significant change in an entity’s assets or activities. A qualitative analysis of control determines the party that consolidates a VIE. This assessment is based on (i) what party has the power to direct the most significant activities of the VIE that impact its economic performance, and (ii) what party has rights to receive benefits or is obligated to absorb losses that are significant to the VIE. The analysis of the party that consolidates a VIE is a continual reassessment.
	No financial support was provided to any of the consolidated VIEs during the years ended December 31, 2014, 2013 and 2012, or is expected to be provided in the future, that was not previously contractually required.
	CONSOLIDATED VIEs
	The following tables summarize the impact of VIEs consolidated by Duke Energy and the Subsidiary Registrants on the Consolidated Balance Sheets.
		December 31, 2014
		Duke Energy
		Duke Energy Carolinas			Duke Energy Progress				Duke Energy Florida
	(in millions)	DERF			DEPR(c)				DEFR(c)			CRC			Renewables			Other			Total
	ASSETS
	Current Assets
	Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	$	647		$	436			$	305		$	547		$	20		$	18		$	1,973
	Other	—			—				—			—			68			6			74
	Investments and Other Assets
	Other	—			—				—			—			25			25			50
	Property, Plant and Equipment
	Property, plant and equipment, cost(a)	—			—				—			—			1,855			18			1,873
	Accumulated depreciation and amortization	—			—				—			—			(250		)	(5		)	(255		)
	Regulatory Assets and Deferred Debits
	Other	—			—				—			—			34			2			36
	Total assets	$	647		$	436			$	305		$	547		$	1,752		$	64		$	3,751
	LIABILITIES AND EQUITY
	Current Liabilities
	Accounts payable	—			—				—			—			3			—			3
	Taxes accrued	—			—				—			—			6			—			6
	Current maturities of long-term debt	—			—				—			—			68			16			84
	Other	—			—				—			—			16			5			21
	Long-Term Debt(b)	400			300				225			325			967			17			2,234
	Deferred Credits and Other Liabilities
	Deferred income taxes	—			—				—			—			283			—			283
	Asset retirement obligations	—			—				—			—			29			—			29
	Other	—			—				—			—			34			4			38
	Total liabilities	$	400		$	300			$	225		$	325		$	1,406		$	42		$	2,698
	Net assets of consolidated variable interest entities	$	247		$	136			$	80		$	222		$	346		$	22		$	1,053
	(a)	Restricted as collateral for non-recourse debt of VIEs.
	(b)	Non-recourse to the general assets of the applicable registrant.
	(c)	The amount for Progress Energy is equal to the amount for Duke Energy Progress Receivables Company, LLC (DEPR) and Duke Energy Florida Receivables Company, LLC (DEFR).
		December 31, 2013
		Duke Energy
		Duke Energy Carolinas			Duke Energy Progress
	(in millions)	DERF			DEPR(c)				CRC			Renewables			Other			Total
	ASSETS
	Current Assets
	Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	$	673		$	416			$	595		$	18		$	17		$	1,719
	Other	—			—				—			89			12			101
	Investments and Other Assets
	Other	—			—				—			29			51			80
	Property, Plant and Equipment
	Property, plant and equipment, cost(a)	—			—				—			1,662			18			1,680
	Accumulated depreciation and amortization	—			—				—			(170		)	(5		)	(175		)
	Regulatory Assets and Deferred Debits
	Other	1			1				—			34			—			36
	Total assets	$	674		$	417			$	595		$	1,662		$	93		$	3,441
	LIABILITIES AND EQUITY
	Current Liabilities
	Accounts payable	—			—				—			2			—			2
	Taxes accrued	—			—				—			10			—			10
	Current maturities of long-term debt	—			—				—			66			14			80
	Other	—			—				—			17			10			27
	Long-Term Debt(b)	400			300				325			907			34			1,966
	Deferred Credits and Other Liabilities														—
	Deferred income taxes	—			—				—			290			—			290
	Asset retirement obligations	—			—				—			26			—			26
	Other	1			—				—			17			13			31
Total liabilities	$	401		$	300			$	325		$	1,335		$	71		$	2,432
Net assets of consolidated variable interest entities	$	273		$	117			$	270		$	327		$	22		$	1,009
(a)	Restricted as collateral for non-recourse debt of VIEs.
(b)	Non-recourse to the general assets of the applicable registrant.
(c)	The amount Progress Energy is equal to the amount for DEPR.
The obligations of these VIEs are non-recourse to Duke Energy, Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida. These entities have no requirement to provide liquidity to, purchase assets of, or guarantee performance of these VIEs unless noted in the following paragraphs.
DERF / DEPR / DEFR
Duke Energy Receivables Finance Company, LLC (DERF), DEPR, and DEFR are bankruptcy remote, special purpose subsidiaries of Duke Energy Carolinas, Duke Energy Progress, and Duke Energy Florida, respectively. On a daily basis, DERF, DEPR, and DEFR buy certain accounts receivable arising from the sale of electricity and/or related services from their parent companies. DERF, DEPR, and DEFR are wholly owned limited liability companies with separate legal existence from their parents, and their assets are not generally available to creditors of their parent companies. DERF, DEPR, and DEFR borrow amounts under credit facilities to buy the receivables. Borrowing availability is limited to the amount of qualified receivables sold, which is generally expected to be in excess of the credit facilities. The credit facilities are reflected on the Consolidated Balance Sheets as Long-Term Debt. The secured credit facilities were not structured to meet the criteria for sale accounting treatment under the accounting guidance for transfers and servicing of financial assets.
The most significant activity that impacts the economic performance of DERF, DEPR, and DEFR are the decisions made to manage delinquent receivables. Duke Energy Carolinas, Duke Energy Progress, and Duke Energy Florida consolidate DERF, DEPR, and DEFR, respectively, as they make those decisions.
The following table outlines amounts and expiration dates of the credit facilities.
	DERF		DEPR			DEFR
Credit facility amount (in millions)	$	400	$	300		$	225
Expiration date	Oct-16		Dec-16			Mar-17
CRC
On a revolving basis, CRC buys certain accounts receivable arising from the sale of electricity and/or related services from Duke Energy Ohio and Duke Energy Indiana. Receivables sold are securitized by CRC through a credit facility managed by two unrelated third parties. The proceeds Duke Energy Ohio and Duke Energy Indiana receive from the sale of receivables to CRC are typically 75 percent cash and 25 percent in the form of a subordinated note from CRC. The subordinated note is a retained interest in the receivables sold. Cash collections from the receivables are the sole source of funds to satisfy the related debt obligation. Depending on experience with collections, additional equity infusions to CRC may be required by Duke Energy to maintain a minimum equity balance of $3 million. There were no infusions to CRC during the years ended December 31, 2014 and 2013. Borrowing availability is limited to the amount of qualified receivables sold, which is generally expected to be in excess of the credit facility. The credit facility expires in November 2016 and is reflected on the Consolidated Balance Sheets as Long-Term Debt.
CRC is considered a VIE because (i) equity capitalization is insufficient to support its operations, (ii) power to direct the most significant activities that impact economic performance of the entity are not performed by the equity holder, Cinergy, and (iii) deficiencies in net worth of CRC are not funded by Cinergy, but by Duke Energy. The most significant activity of CRC relates to the decisions made with respect to the management of delinquent receivables. Duke Energy consolidates CRC as it makes these decisions. Neither Duke Energy Ohio nor Duke Energy Indiana consolidate CRC.
Renewables
Certain of Duke Energy’s renewable energy facilities are VIEs due to long-term fixed price power purchase agreements. These fixed price agreements effectively transfer commodity price risk to the buyer of the power. Certain other of Duke Energy’s renewable energy facilities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. For certain VIEs, assets are restricted and cannot be pledged as collateral or sold to third parties without prior approval of debt holders. The most significant activities that impact the economic performance of these renewable energy facilities were decisions associated with siting, negotiating purchase power agreements, engineering, procurement and construction, and decisions associated with ongoing operations and maintenance-related activities. Duke Energy consolidates the entities as it makes all of these decisions.
NON-CONSOLIDATED VIEs
The tables below show VIEs not consolidated and how these entities impact the Consolidated Balance Sheets.
	December 31, 2014
	Duke Energy
(in millions)	Renewables			Other				Total			Duke Energy			Duke Energy
											Ohio			Indiana
Receivables	$	—		$	—			$	—		$	91		$	113
Investments in equity method unconsolidated affiliates	150			38				188			—			—
Investments and other assets	—			4				4			—			—
Total assets(a)	$	150		$	42			$	192		$	91		$	113
Other current liabilities	—			3				3			—			—
Deferred credits and other liabilities	—			14				14			—			—
Total liabilities	$	—		$	17			$	17		$	—		$	—
Net assets (liabilities)	$	150		$	25			$	175		$	91		$	113
(a)	Duke Energy Ohio recorded a pretax impairment charge of $94 million related to OVEC.
	December 31, 2013
	Duke Energy
(in millions)	Renewables			Other				Total			Duke Energy Ohio			Duke Energy Indiana
Receivables	$	—		$	—			$	—		$	114		$	143
Investments in equity method unconsolidated affiliates	153			60				213			—			—
Intangibles	—			96				96			96			—
Investments and other assets	—			4				4			—			—
Total assets	$	153		$	160			$	313		$	210		$	143
Other current liabilities	—			3				3			—			—
Deferred credits and other liabilities	—			15				15			—			—
Total liabilities	$	—		$	18			$	18		$	—		$	—
Net assets	$	153		$	142			$	295		$	210		$	143
The Duke Energy Registrants are not aware of any situations where the maximum exposure to loss significantly exceeds the carrying values shown above except for the power purchase agreement with OVEC, which is discussed below, and various guarantees, some of which are reflected in the table above as Deferred credits and other liabilities. For more information on various guarantees, refer to Note 7, "Guarantees and Indemnifications."
Renewables
Duke Energy has investments in various renewable energy project entities. Some of these entities are VIEs due to long-term fixed price power purchase agreements. These fixed price agreements effectively transfer commodity price risk to the buyer of the power. Duke Energy does not consolidate these VIEs because power to direct and control key activities is shared jointly by Duke Energy and other owners.
Other
At December 31, 2013, the most significant of the Other non-consolidated VIEs was Duke Energy Ohio’s 9 percent ownership interest in OVEC. Through its ownership interest in OVEC, Duke Energy Ohio has a contractual arrangement to buy power from OVEC’s power plants through June 2040. The initial carrying value of this contract was recorded as an intangible asset when Duke Energy acquired Cinergy in April 2006. Proceeds from the sale of power by OVEC to its power purchase agreement counterparties are designed to be sufficient to meet its operating expenses, fixed costs, debt amortization and interest expense, as well as earn a return on equity. Accordingly, the value of this contract is subject to variability due to fluctuations in power prices and changes in OVEC’s costs of business, including costs associated with its 2,256 MW of coal-fired generation capacity. Proposed environmental rulemaking could increase the costs of OVEC, which would be passed through to Duke Energy Ohio. In 2014, Duke Energy recorded a $94 million impairment related to OVEC.
CRC
See discussion under Consolidated VIEs for additional information related to CRC.
Amounts included in Receivables in the above table for Duke Energy Ohio and Duke Energy Indiana reflect their retained interest in receivables sold to CRC. These subordinated notes held by Duke Energy Ohio and Duke Energy Indiana are stated at fair value. Carrying values of retained interests are determined by allocating carrying value of the receivables between assets sold and interests retained based on relative fair value. The allocated bases of the subordinated notes are not materially different than their face value because (i) the receivables generally turnover in less than two months, (ii) credit losses are reasonably predictable due to the broad customer base and lack of significant concentration, and (iii) the equity in CRC is subordinate to all retained interests and thus would absorb losses first. The hypothetical effect on fair value of the retained interests assuming both a 10 percent and a 20 percent unfavorable variation in credit losses or discount rates is not material due to the short turnover of receivables and historically low credit loss history. Interest accrues to Duke Energy Ohio and Duke Energy Indiana on the retained interests using the acceptable yield method. This method generally approximates the stated rate on the notes since the allocated basis and the face value are nearly equivalent. An impairment charge is recorded against the carrying value of both retained interests and purchased beneficial interest whenever it is determined that an other-than-temporary impairment has occurred.
Key assumptions used in estimating fair value are detailed in the following table.
	Duke Energy Ohio					Duke Energy Indiana
	2014		2013			2014			2013
Anticipated credit loss ratio	0.6	%	0.6	%		0.3	%		0.3	%
Discount rate	1.2	%	1.2	%		1.2	%		1.2	%
Receivable turnover rate	12.8	%	12.8	%		10.5	%		10.3	%
The following table shows the gross and net receivables sold.
	Duke Energy Ohio							Duke Energy Indiana
(in millions)	2014			2013				2014			2013
Receivables sold	$	273		$	290			$	310		$	340
Less: Retained interests	91			114				113			143
Net receivables sold	$	182		$	176			$	197		$	197
The following table shows sales and cash flows related to receivables sold.
	Duke Energy Ohio										Duke Energy Indiana
	Years Ended December 31,										Years Ended December 31,
(in millions)	2014			2013				2012			2014			2013			2012
Sales
Receivables sold	$	2,246		$	2,251			$	2,154		$	2,913		$	2,985		$	2,773
Loss recognized on sale	11			12				13			11			11			12
Cash Flows
Cash proceeds from receivables sold	2,261			2,220				2,172			2,932			2,944			2,784
Collection fees received	1			1				1			1			1			1
Return received on retained interests	4			5				5			6			6			7
Cash flows from the sales of receivables are reflected within Operating Activities on Duke Energy Ohio’s and Duke Energy Indiana’s Consolidated Statements of Cash Flows.
Collection fees received in connection with servicing transferred accounts receivable are included in Operation, maintenance and other on Duke Energy Ohio’s and Duke Energy Indiana’s Consolidated Statements of Operations and Comprehensive Income. The loss recognized on sales of receivables is calculated monthly by multiplying receivables sold during the month by the required discount. The required discount is derived monthly utilizing a three-year weighted average formula that considers charge-off history, late charge history and turnover history on the sold receivables, as well as a component for the time value of money. The discount rate, or component for the time value of money, is the prior month-end LIBOR plus a fixed rate of 1.00 percent.

Common_Stock

Common Stock	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Common Stock	COMMON STOCK
	Basic Earnings Per Share (EPS) is computed by dividing net income attributable to Duke Energy common shareholders, adjusted for distributed and undistributed earnings allocated to participating securities, by the weighted-average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income attributable to Duke Energy common shareholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the diluted weighted-average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as stock options, phantom shares and stock-based performance unit awards were exercised or settled. Duke Energy’s participating securities are restricted stock units that are entitled to dividends declared on Duke Energy common shares during the restricted stock units’ vesting period.
	On July 2, 2012, just prior to the close of the merger with Progress Energy, Duke Energy executed a one-for-three reverse stock split. All earnings per share amounts included in this 10-K are presented as if the one-for-three reverse stock split had been effective January 1, 2012. The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted-average number of common shares outstanding to the diluted weighted-average number of common shares outstanding.
		Years Ended December 31,
	(in millions, except per share amounts)	2014		2013	2012
	Income from continuing operations attributable to Duke Energy common shareholders excluding impact of participating securities	2,446		2,565	1,588
	Weighted-average shares outstanding - basic	707		706	574
	Stock options, performance and restricted shares	—		—	1
	Weighted-average shares outstanding - diluted	707		706	575
	Earnings per share from continuing operations attributable to Duke Energy common shareholders
	Basic	$	3.46	3.64	2.77
	Diluted	$	3.46	3.63	2.77
	Potentially dilutive items excluded from the calculation(a)	2		2	1
	Dividends declared per common share	$	3.15	3.09	3.03
	(a)	Stock options and performance and unvested stock awards were not included in the dilutive securities calculation because either the option exercise prices were greater than the average market price of the common shares during those periods, or performance measures related to the awards had not yet been met.

Severance

Severance	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Severance	SEVERANCE
	In conjunction with the merger with Progress Energy, in November 2011 Duke Energy and Progress Energy offered a voluntary severance plan to certain eligible employees. Approximately 1,100 employees from Duke Energy and Progress Energy requested severance during the voluntary window, which closed on November 30, 2011. As this was a voluntary severance plan, all severance benefits offered under this plan are considered special termination benefits under U.S. GAAP. Special termination benefits are measured upon employee acceptance and recorded immediately absent any significant retention period. If a significant retention period exists, the cost of the special termination benefits are recorded ratably over the retention period. Most plan participants have separated from the company as of December 31, 2014. The amount of severance expense associated with this voluntary plan, and other severance expense for involuntary terminations related to the merger, was not material for the year ended December 31, 2014.
	Amounts included in the table below represent direct and allocated severance and related expense recorded by the Duke Energy Registrants, and are in Operation, maintenance and other within Operating Expenses on the Consolidated Statements of Operations.
		Year Ended December 31,
	(in millions)	2013		2012
	Duke Energy(a)	$	34	$	201
	Duke Energy Carolinas	8		63
	Progress Energy	19		82
	Duke Energy Progress	14		55
	Duke Energy Florida	5		27
	Duke Energy Ohio	2		21
	Duke Energy Indiana	2		18
	(a)	Includes $5 million and $14 million of accelerated stock award expense and $2 million and $19 million of COBRA and health care reimbursement expenses for 2013 and 2012, respectively.
	In conjunction with the retirement of Crystal River Unit 3, severance benefits have been made available to certain eligible impacted unionized and non-unionized employees, to the extent that those employees do not find job opportunities at other locations. Approximately 600 employees worked at Crystal River Unit 3. For the year ended December 31, 2013, Duke Energy Florida deferred $26 million of severance costs as a regulatory asset. Duke Energy Florida did not defer severance costs as a regulatory asset for the year ended December 31, 2014. Severance costs expected to be accrued over the remaining retention period for employees identified to have a significant retention period is not material. However, these employees maintain the ability to accept job opportunities at other Duke Energy locations, which would result in severance not being paid. If a significant amount of these individuals redeploy within Duke Energy, the final severance benefits paid under the plan may be less than what has been accrued to date. Refer to Note 4 for further discussion regarding Crystal River Unit 3.
	During 2014, in conjunction with the disposition of the nonregulated Midwest Generation business, severance benefits have been made available to certain eligible non-unionized employees, to the extent those employees do not find other job opportunities. Approximately 50 employees are expected to receive benefits. Duke Energy Ohio recorded severance expense of $6 million and included in (Loss) Income from Discontinued Operations, net of tax in the Duke Energy Statements of Operations and Comprehensive Income for the year ended December 31, 2014. For further information related to the Midwest Generation Exit, see Note 2, "Acquisitions, Dispositions and Sales of Other Assets."
	Amounts included in the table below represent the severance liability for past and ongoing severance plans. Amounts for Subsidiary Registrants do not include allocated expense or associated cash payments. Amounts for Duke Energy Indiana are not material.
	(in millions)	Balance at December 31, 2013		Provision / Adjustments			Cash Reductions			Balance at December 31, 2014
	Duke Energy	$	64	$	5		$	(41	)	28
	Duke Energy Carolinas	5		2			(5		)	2
	Progress Energy	44		(10		)	(16		)	18
	Duke Energy Progress	11		—			(10		)	1
	Duke Energy Florida	24		(1		)	(6		)	17
	Duke Energy Ohio	2		5			(1		)	6
	As part of Duke Energy Carolinas’ 2011 rate case, the NCUC approved the recovery of $101 million of previously recorded expenses related to a prior year Voluntary Opportunity Plan. This amount was recorded as a reduction to Operation, maintenance, and other within Operating Expenses on the Consolidated Statements of Operations and recognized as a Regulatory asset on the Consolidated Balance Sheets in 2012.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION
	Duke Energy’s 2010 Long-Term Incentive Plan (the 2010 Plan) reserved 25 million shares of common stock for awards to employees and outside directors. Duke Energy has historically issued new shares upon exercising or vesting of share-based awards. However, Duke Energy may use a combination of new share issuances and open market repurchases for share-based awards that are exercised or become vested in the future. Duke Energy has not determined with certainty the amount of such new share issuances or open market repurchases.
	The 2010 Plan allows for a maximum of 6.25 million shares of common stock to be issued under various stock-based awards other than options and stock appreciation rights.
	In connection with the acquisition of Progress Energy in July 2012, Duke Energy assumed Progress Energy’s 2007 Equity Incentive Plan (EIP). Stock-based awards granted under the Progress Energy EIP and held by Progress Energy employees were generally converted into outstanding Duke Energy stock-based compensation awards. The estimated fair value of these awards allocated to the purchase price was $62 million. Refer to Note 2 for further information regarding the merger transaction.
	The following table summarizes the total expense recognized by each of the Duke Energy Registrants, net of tax, for stock-based compensation.
		Years Ended December 31,
	(in millions)	2014			2013			2012
	Duke Energy	$	38		$	52		$	48
	Duke Energy Carolinas	12			13			12
	Progress Energy	14			23			25
	Duke Energy Progress	9			14			16
	Duke Energy Florida	5			9			9
	Duke Energy Ohio	5			4			4
	Duke Energy Indiana	3			4			4
	Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense, and stock-based compensation costs capitalized are included in the following table.
		Years Ended December 31,
	(in millions)	2014			2013			2012
	Restricted stock unit awards	$	39		$	49		$	43
	Performance awards	22			34			33
	Stock options	—			2			2
	Pretax stock-based compensation cost	$	61		$	85		$	78
	Tax benefit associated with stock-based compensation expense	$	23		$	33		$	30
	Stock-based compensation costs capitalized	4			3			2
	STOCK OPTIONS
	The following table summarizes information about stock options outstanding.
		Options		Weighted-Average Exercise Price (per share)			Weighted-Average Remaining Life		Aggregate Intrinsic Value
		(in thousands)							(in millions)
	Outstanding at December 31, 2013	793		$	61
	Exercised	(420	)	59
	Outstanding at December 31, 2014	373		64			6 years, 10 months		$	7
	Exercisable at December 31, 2014	53		46			1 year		2
	Options expected to vest	320		67			7 years, 10 months		5
	The exercise price of each option granted cannot be less than the market price of Duke Energy’s common stock on the date of grant and the maximum option term is 10 years. The vesting periods range from immediate to three years. Options granted in 2013 and 2012 were expensed immediately; therefore, there is no future compensation cost associated with these options.
	The following table summarizes additional information related to stock options exercised and granted.
		Years Ended December 31,
		2014			2013			2012
	Intrinsic value of options exercised (in millions)	$	6		$	26		$	17
	Tax benefit related to options exercised (in millions)	2			10			7
	Cash received from options exercised (in millions)	25			9			21
	Stock options granted (in thousands)	—			310			340
	RESTRICTED STOCK UNIT AWARDS
	Restricted stock unit awards issued and outstanding generally vest over periods from immediate to 3 years. Fair value amounts are based on the market price of Duke Energy's common stock at the grant date. The following table includes information related to restricted stock unit awards.
		Years Ended December 31,
		2014			2013			2012
	Shares awarded (in thousands)	557			612			443
	Fair value (in millions)	$	40		$	42		$	28
	The following table summarizes information about restricted stock unit awards outstanding.
		Shares		Weighted-Average
		(in thousands)		Grant Date Fair Value
				(Per Share)
	Outstanding at December 31, 2013	1,400		$	66
	Granted	557		71
	Vested	(832	)	62
	Forfeited	(45	)	68
	Outstanding at December 31, 2014	1,080		69
	Restricted stock unit awards expected to vest	1,057		69
	The total grant date fair value of shares vested during the years ended December 31, 2014, 2013 and 2012 was $52 million, $50 million and $34 million, respectively. At December 31, 2014, Duke Energy had $18 million of unrecognized compensation cost, which is expected to be recognized over a weighted-average period of one year, ten months.
	PERFORMANCE AWARDS
	Stock-based awards issued and outstanding generally vest over three years if performance targets are met.
	Certain performance awards granted in 2014, 2013 and 2012 contain market conditions based on the total shareholder return (TSR) of Duke Energy stock relative to a predefined peer group (relative TSR). These awards are valued using a path-dependent model that incorporates expected relative TSR into the fair value determination of Duke Energy’s performance-based share awards. The model uses three-year historical volatilities and correlations for all companies in the predefined peer group, including Duke Energy, to simulate Duke Energy’s relative TSR as of the end of the performance period. For each simulation, Duke Energy’s relative TSR associated with the simulated stock price at the end of the performance period plus expected dividends within the period results in a value per share for the award portfolio. The average of these simulations is the expected portfolio value per share. Actual life to date results of Duke Energy’s relative TSR for each grant is incorporated within the model.
	Other performance awards not containing market conditions were awarded in 2012. The performance goal for these awards is Duke Energy’s return on equity over a three-year period. Awards are measured at grant date price.
	The following table includes information related to performance awards.
		Years Ended December 31,
		2014			2013			2012
Shares awarded (in thousands)	542			633			352
Fair value (in millions)	$	19		$	28		$	19
The following table summarizes information about stock-based performance awards outstanding at the maximum level.
	Shares		Weighted-Average
	(in thousands)		Grant Date Fair Value
			(per share)
Outstanding at December 31, 2013	1,822		$	46
Granted	542		34
Vested	(524	)	52
Forfeited	(213	)	37
Outstanding at December 31, 2014	1,627		42
Stock-based performance awards expected to vest	1,418		42
The total grant date fair value of shares vested during the years ended December 31, 2014, 2013 and 2012 was $27 million, $42 million and $56 million, respectively. At December 31, 2014, Duke Energy had $21 million of unrecognized compensation cost, which is expected to be recognized over a weighted-average period of one year, nine months.
The grant date fair value of performance awards granted in 2014 was determined based on a risk-fee interest rate of 0.7 percent, which reflects the yield on three-year Treasury bonds as of the grant date, and an expected volatility of 13.5 percent based on Duke Energy's historical volatility over three years using daily stock prices.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS
	DEFINED BENEFIT RETIREMENT PLANS
	Duke Energy maintains, and the Subsidiary Registrants participate in, qualified, non-contributory defined benefit retirement plans. The plans cover most U.S. employees using a cash balance formula. Under a cash balance formula, a plan participant accumulates a retirement benefit consisting of pay credits based upon a percentage of current eligible earnings based on age and/or years of service and interest credits. Certain employees are covered under plans that use a final average earnings formula. Under these average earnings formulas, a plan participant accumulates a retirement benefit equal to the sum of percentages of their (i) highest three-year or four-year average earnings, (ii) highest three-year or four-year average earnings in excess of covered compensation per year of participation (maximum of 35 years), and/or (iii) highest three or four-year average earnings times years of participation in excess of 35 years. Duke Energy also maintains, and the Subsidiary Registrants participate in, non-qualified, non-contributory defined benefit retirement plans which cover certain executives. As of January 1, 2014, the qualified and non-qualified non-contributory defined benefit plans are closed to new and rehired non-union and certain unionized employees.
	Duke Energy uses a December 31 measurement date for its defined benefit retirement plan assets and obligations.
	Net periodic benefit costs disclosed in the tables below represent the cost of the respective benefit plan for the periods presented. However, portions of the net periodic benefit costs disclosed in the tables below have been capitalized as a component of property, plant and equipment. Amounts presented in the tables below for the Subsidiary Registrants represent the amounts of pension and other post-retirement benefit cost allocated by Duke Energy for employees of the Subsidiary Registrants. Additionally, the Subsidiary Registrants are allocated their proportionate share of pension and post-retirement benefit cost for employees of Duke Energy’s shared services affiliate that provide support to the Subsidiary Registrants. These allocated amounts are included in the governance and shared service costs discussed in Note 13.
	Duke Energy’s policy is to fund amounts on an actuarial basis to provide assets sufficient to meet benefit payments to be paid to plan participants. The following table includes information related to the Duke Energy Registrants’ contributions to its U.S. qualified defined benefit pension plans.
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Anticipated Contributions:
	2015	$	302			$	91			$	83			$	42			$	40			$	8		$	19
	Contributions Made:
	2014	$	—			$	—			$	—			$	—			$	—			$	—		$	—
	2013	250				—				250				63				133				—			—
	2012	304				—				346				141				128				—			—
	QUALIFIED PENSION PLANS
	Components of Net Periodic Pension Costs
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	135			$	41			$	40			$	21			$	20			$	4		$	9
	Interest cost on projected benefit obligation	344				85				112				54				57				20			29
	Expected return on plan assets	(511		)		(132		)		(173		)		(85		)		(85		)		(27		)	(41		)
	Amortization of actuarial loss	150				36				68				32				32				4			13
	Amortization of prior service credit	(15		)		(8		)		(3		)		(2		)		(1		)		—			—
	Other	8				2				3				1				1				—			1
	Net periodic pension costs	$	111			$	24			$	47			$	21			$	24			$	1		$	11
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	167			$	49			$	60			$	22			$	30			$	6		$	11
	Interest cost on projected benefit obligation	320				80				116				50				53				21			28
	Expected return on plan assets	(549		)		(148		)		(199		)		(94		)		(87		)		(31		)	(46		)
	Amortization of actuarial loss	244				60				101				46				49				13			24
	Amortization of prior service (credit) cost	(11		)		(6		)		(4		)		(1		)		(2		)		—			1
	Other	7				2				2				1				1				—			1
	Net periodic pension costs	$	178			$	37			$	76			$	24			$	44			$	9		$	19
		Year Ended December 31, 2012
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	122			$	35			$	63			$	25			$	30			$	6		$	9
	Interest cost on projected benefit obligation	307				90				127				58				56				31			30
	Expected return on plan assets	(472		)		(146		)		(188		)		(96		)		(81		)		(45		)	(46		)
	Amortization of actuarial loss	144				45				93				37				48				10			15
	Amortization of prior service cost (credit)	10				1				9				8				(1		)		1			1
	Other	6				2				2				1				1				—			—
	Net periodic pension costs	$	117			$	27			$	106			$	33			$	53			$	3		$	9
	Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net increase (decrease)	$	112			$	30			$	(73	)		$	(17	)		$	11			$	17		$	4
	Accumulated other comprehensive (income) loss
	Deferred income tax expense	$	(10	)		—				(2		)		—				—				—			—
	Actuarial losses arising during the year	29				—				—				—				—				—			—
	Prior year service credit arising during the year	—				—				—				—				—				—			—
	Amortization of prior year actuarial losses	(9		)		—				—				—				—				—			—
	Reclassification of actuarial losses to regulatory assets	(1		)		—				—				—				—				—			—
	Net amount recognized in accumulated other comprehensive income	$	9			$	—			$	(2	)		$	—			$	—			$	—		$	—
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net decrease	$	(788	)		$	(205	)		$	(253	)		$	(109	)		$	(146	)		$	(96	)	$	(99	)
	Accumulated other comprehensive (income) loss
	Deferred income tax benefit	$	18			$	—			$	—			$	—			$	—			$	—		$	—
	Actuarial gains arising during the year	(33		)		—				(2		)		—				—				—			—
	Prior year service credit arising during the year	(1		)		—				—				—				—				—			—
	Amortization of prior year actuarial losses	(15		)		—				(3		)		—				—				—			—
	Reclassification of actuarial losses to regulatory assets	3				—				—				—				—				—			—
	Net amount recognized in accumulated other comprehensive income	$	(28	)		$	—			$	(5	)		$	—			$	—			$	—		$	—
	Reconciliation of Funded Status to Net Amount Recognized
	Year Ended December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	7,510			$	1,875			$	2,739			$	1,172			$	1,233			$	442		$	632
Service cost	135				41				40				21				20				4			9
Interest cost	344				85				112				54				57				20			29
Actuarial loss(a)	618				132				211				98				105				41			41
Transfers	—				37				(375		)		(61		)		(9		)		(6		)	—
Plan amendments	(4		)		(1		)		—				—				—				(1		)	—
Benefits paid	(496		)		(116		)		(170		)		(97		)		(71		)		(31		)	(38		)
Obligation at measurement date	$	8,107			$	2,053			$	2,557			$	1,187			$	1,335			$	469		$	673
Accumulated Benefit Obligation at measurement date	$	7,966			$	2,052			$	2,519			$	1,187			$	1,297			$	459		$	645
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	8,142			$	2,162			$	2,944			$	1,330			$	1,299			$	448		$	654
Actual return on plan assets	852				217				300				149				144				45			65
Benefits paid	(496		)		(116		)		(170		)		(97		)		(71		)		(31		)	(38		)
Transfers	—				37				(352		)		(61		)		(9		)		(6		)	—
Plan assets at measurement date	$	8,498			$	2,300			$	2,722			$	1,321			$	1,363			$	456		$	681
Funded status of plan	$	391			$	247			$	165			$	134			$	28			$	(13	)	$	8
(a)	Includes an increase in benefit obligation of $180 million as a result of changes in Duke Energy's mortality assumptions.
	Year Ended December 31, 2013
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Change in Projected Benefit Obligation
Obligation at prior measurement date	8,030				2,028				2,868				1,264				1,309				527			684
Service cost	167				49				60				22				30				6			11
Interest cost	320				80				116				50				53				21			28
Actuarial gains	(399		)		(73		)		(118		)		(26		)		(75		)		(71		)	(56		)
Transfers	—				(26		)		(7		)		(45		)		(17		)		(2		)	(2		)
Plan amendments	(41		)		(13		)		(19		)		(8		)		(7		)		—			—
Benefits paid	(567		)		(170		)		(161		)		(85		)		(60		)		(39		)	(33		)
Obligation at measurement date	7,510				1,875				2,739				1,172				1,233				442			632
Accumulated Benefit Obligation at measurement date	7,361				1,875				2,698				1,172				1,192				429			608
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	7,754				2,151				2,647				1,289				1,150				446			627
Actual return on plan assets	705				207				215				108				93				43			62
Benefits paid	(567		)		(170		)		(161		)		(85		)		(60		)		(39		)	(33		)
Transfers	—				(26		)		(7		)		(45		)		(17		)		(2		)	(2		)
Employer contributions	250				—				250				63				133				—			—
Plan assets at measurement date	$	8,142			$	2,162			$	2,944			$	1,330			$	1,299			$	448		$	654
Funded status of plan	$	632			$	287			$	205			$	158			$	66			$	6		$	22
Amounts Recognized in the Consolidated Balance Sheets
	December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Prefunded pension(a)	$	441			$	247			$	165			$	134			$	28			$	—		$	8
Non-current pension liability(b)	$	50			$	—			$	—			$	—			$	—			$	13		$	—
Net asset recognized	$	391			$	247			$	165			$	134			$	28			$	(13	)	$	8
Regulatory assets	$	1,711			$	407			$	753			$	346			$	406			$	65		$	151
Accumulated other comprehensive (income) loss
Deferred income tax asset	$	(51	)		$	—			$	(11	)		$	—			$	—			$	—		$	—
Prior service credit	(5		)		—				—				—				—				—			—
Net actuarial loss	140				—				21				—				—				—			—
Net amounts recognized in accumulated other comprehensive loss(c)	$	84			$	—			$	10			$	—			$	—			$	—		$	—
Amounts to be recognized in net periodic pension expense in the next year
Unrecognized net actuarial loss	$	166			$	39			$	65			$	34			$	31			$	6		$	14
Unrecognized prior service credit	(15		)		(8		)		(3		)		(2		)		(1		)		—			—
	December 31, 2013
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Prefunded pension(a)	$	632			$	287			$	230			$	158			$	66			$	2		$	75
Non-current pension liability(b)	$	—			$	—			$	25			$	—			$	—			$	(4	)	$	53
Net asset recognized	$	632			$	287			$	205			$	158			$	66			$	6		$	22
Regulatory assets	$	1,599			$	377			$	826			$	363			$	395			$	48		$	147
Accumulated other comprehensive (income) loss
Deferred income tax asset	$	(41	)		$	—			$	(9	)		$	—			$	—			$	—		$	—
Prior service credit	(5		)		—				—				—				—				—			—
Net actuarial loss	121				—				21				—				—				—			—
Net amounts recognized in accumulated other comprehensive loss(c)	$	75			$	—			$	12			$	—			$	—			$	—		$	—
(a)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheets.
(b)	Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.
(c)	Excludes accumulated other comprehensive income of $22 million and $16 million as of 2014 and 2013, respectively, net of tax, associated with a Brazilian retirement plan.
Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets
	December 31, 2014
(in millions)	Duke Energy				Duke Energy Ohio
Projected benefit obligation	$	702			$	315
Accumulated benefit obligation	672				306
Fair value of plan assets	652				302
As of December 31, 2013, none of the qualified pension plans had an accumulated benefit obligation in excess of plan assets.
Assumptions Used for Pension Benefits Accounting
The discount rate used to determine the current year pension obligation and following year’s pension expense is based on a bond selection-settlement portfolio approach. This approach develops a discount rate by selecting a portfolio of high quality corporate bonds that generate sufficient cash flow to provide for projected benefit payments of the plan. The selected bond portfolio is derived from a universe of non-callable corporate bonds rated Aa quality or higher. After the bond portfolio is selected, a single interest rate is determined that equates the present value of the plan’s projected benefit payments discounted at this rate with the market value of the bonds selected.
The average remaining service period of active covered employees is nine years for Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio and Duke Energy Indiana.
The following tables present the assumptions or range of assumptions used for pension benefit accounting.
		December 31,
		2014					2013					2012(a)
Benefit Obligations
Discount rate					4.10%					4.70%					4.10%
Salary increase		4	%	-	4.40%		4	%	-	4.40%		4	%	-	4.30%
Net Periodic Benefit Cost
Discount rate					4.70%					4.10%		4.6	%	-	5.10%
Salary increase		4	%	-	4.40%		4	%	-	4.30%		4	%	-	4.40%
Expected long-term rate of return on plan assets					6.75%					7.75%		8	%	-	8.25%
(a)	For Progress Energy plans, the assumptions used in 2012 to determine net periodic pension costs reflect remeasurement as of July 1, 2012, due to the merger between Duke Energy and Progress Energy.
Expected Benefit Payments
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Years ending December 31,
2015	$	584		$	175		$	150		$	80		$	67		$	34		$	45
2016	604			184			158			85			70			35			46
2017	616			195			161			86			73			34			45
2018	625			200			165			87			76			34			46
2019	626			194			168			88			78			34			46
2020 - 2024	3,107			924			868			437			420			168			229
NON-QUALIFIED PENSION PLANS
Components of Net Periodic Pension Costs
	Year Ended December 31, 2014
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Service cost	$	3		$	—		$	1		$	1		$	—		$	—		$	—
Interest cost on projected benefit obligation	14			1			5			1			2			—			—
Amortization of actuarial loss	3			—			2			—			—			—			—
Amortization of prior service credit	(1		)	—			(1		)	—			—			—			—
Net periodic pension costs	$	19		$	1		$	7		$	2		$	2		$	—		$	—
	Year Ended December 31, 2013
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Service cost	$	3		$	—		$	1		$	1		$	—		$	—		$	—
Interest cost on projected benefit obligation	13			1			7			1			1			—			—
Amortization of actuarial loss	5			—			3			1			1			—			—
Amortization of prior service credit	(1		)	—			(1		)	—			—			—			—
Net periodic pension costs	$	20		$	1		$	10		$	3		$	2		$	—		$	—
	Year Ended December 31, 2012
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Service cost	$	2		$	—		$	2		$	1		$	—		$	—		$	—
Interest cost on projected benefit obligation	12			1			8			1			2			—			—
Amortization of actuarial loss	4			—			5			1			—			—			—
Amortization of prior service cost (credit)	1			—			(1		)	—			—			—			—
Net periodic pension costs	$	19		$	1		$	14		$	3		$	2		$	—		$	—
Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities
	Year Ended December 31, 2014
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Regulatory assets, net increase	$	44		$	1		$	14		$	4		$	19		$	1		$	2
Regulatory liabilities, net decrease	$	(7	)	$	—		$	—		$	—		$	—		$	—		$	—
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	4		$	—		$	5		$	—		$	—		$	—		$	—
Actuarial gains arising during the year	(9		)	—			(11		)	—			—			—			—
Net amount recognized in accumulated other comprehensive loss (income)	$	(5	)	$	—		$	(6	)	$	—		$	—		$	—		$	—
	Year Ended December 31, 2013
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Regulatory assets, net (decrease) increase	$	(14	)	$	1		$	(16	)	$	(4	)	$	(3	)	$	—		$	(2	)
Regulatory liabilities, net increase	$	5		$	—		$	—		$	—		$	—		$	—		$	—
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	—		$	—		$	1		$	—		$	—		$	—		$	—
Actuarial losses (gains) arising during the year	2			—			(5		)	—			—			—			—
Prior year service credit arising during the year	(1		)	—			—			—			—			—			—
Net amount recognized in accumulated other comprehensive loss (income)	$	1		$	—		$	(4	)	$	—		$	—		$	—		$	—
Reconciliation of Funded Status to Net Amount Recognized
	Year Ended December 31, 2014
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	304		$	15		$	140		$	34		$	39		$	3		$	5
Service cost	3			—			1			1			—			—			—
Interest cost	14			1			5			1			2			—			—
Actuarial losses(a)	43			2			11			2			20			1			1
Settlements	—			—			—			—			—			—			—
Plan amendments	—			—			—			—			—			—			—
Transfers	—			—			(32		)	—			4			—			—
Benefits paid	(27		)	(2		)	(9		)	(3		)	(4		)	—			(1		)
Obligation at measurement date	$	337		$	16		$	116		$	35		$	61		$	4		$	5
Accumulated Benefit Obligation at measurement date	$	333		$	15		$	116		$	35		$	61		$	4		$	5
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	—			—			—			—			—			—			—
Benefits paid	(27		)	(2		)	(9		)	(3		)	(4		)	—			(1		)
Employer contributions	27			2			9			3			4			—			1
Plan assets at measurement date	$	—		$	—		$	—		$	—		$	—		$	—		$	—
(a)	Includes an increase in benefit obligation of $21 million as a result of changes in Duke Energy's mortality assumptions.
	Year Ended December 31, 2013
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Change in Projected Benefit Obligation
Obligation at prior measurement date	$	335		$	16		$	176		$	38		$	45		$	4		$	5
Service cost	3			—			1			1			—			—			—
Interest cost	13			1			7			1			1			—			—
Actuarial (gains) losses	(15		)	1			(11		)	(3		)	(3		)	(1		)	—
Settlements	(5		)	—			—			—			—			—			—
Plan amendments	(1		)	—			—			—			—			—			—
Transfers	—			—			(21		)	—			—			—			—
Benefits paid	(26		)	(3		)	(12		)	(3		)	(4		)	—			—
Obligation at measurement date	$	304		$	15		$	140		$	34		$	39		$	3		$	5
Accumulated Benefit Obligation at measurement date	$	302		$	15		$	140		$	34		$	39		$	3		$	5
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	—			—			—			—			—			—			—
Benefits paid	(26		)	(3		)	(12		)	(3		)	(4		)	—			—
Employer contributions	26			3			12			3			4			—			—
Plan assets at measurement date	$	—		$	—		$	—		$	—		$	—		$	—		$	—
Amounts Recognized in the Consolidated Balance Sheets
	December 31, 2014
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Current pension liability(a)	$	27		$	2		$	8		$	3		$	4		$	—		$	—
Non-current pension liability(b)	310			14			108			32			57			4			5
Total accrued pension liability	$	337		$	16		$	116		$	35		$	61		$	4		$	5
Regulatory assets	$	89		$	5		$	32		$	7		$	25		$	1		$	2
Regulatory liabilities	$	—		$	—		$	—		$	—		$	—		$	—		$	—
Accumulated other comprehensive (income) loss
Deferred income tax asset	4			—			$	2		—			—			—			—
Prior service credit	(1		)	—			—			—			—			—			—
Net actuarial gain	(8		)	—			(4		)	—			—			—			—
Net amounts recognized in accumulated other comprehensive income	$	(5	)	$	—		$	(2	)	$	—		$	—		$	—		$	—
Amounts to be recognized in net periodic pension expense in the next year
Unrecognized net actuarial loss	$	6		—			$	2		$	1		2			—			—
Unrecognized prior service credit	(1		)	—			—			—			—			—			—
	December 31, 2013
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Current pension liability(a)	$	30		$	2		$	11		$	2		$	3		$	—		$	—
Non-current pension liability(b)	274			13			129			32			36			3			5
Total accrued pension liability	$	304		$	15		$	140		$	34		$	39		$	3		$	5
Regulatory assets	$	45		$	4		$	18		$	3		$	6		$	—		$	—
Regulatory liabilities	$	7		$	—		$	—		$	—		$	—		$	—		$	—
Accumulated other comprehensive (income) loss
Deferred income tax asset	$	—		$	—		$	(3	)	$	—		$	—		$	—		$	—
Prior service credit	(1		)	—			—			—			—			—			—
Net actuarial loss	1			—			7			—			—			—			—
Net amounts recognized in accumulated other comprehensive loss	$	—		$	—		$	4		$	—		$	—		$	—		$	—
(a)	Included in Other within Current Liabilities on the Consolidated Balance Sheets.
(b)	Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.
Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets
	December 31, 2014
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Projected benefit obligation	$	337		$	16		$	116		$	35		$	61		$	4		$	5
Accumulated benefit obligation	333			15			116			35			61			4			5
	December 31, 2013
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Projected benefit obligation	$	304		$	15		$	140		$	34		$	39		$	3		$	5
Accumulated benefit obligation	302			15			140			34			39			3			5
Assumptions Used for Pension Benefits Accounting
The discount rate used to determine the current year pension obligation and following year’s pension expense is based on a bond selection-settlement portfolio approach. This approach develops a discount rate by selecting a portfolio of high quality corporate bonds that generate sufficient cash flow to provide for projected benefit payments of the plan. The selected bond portfolio is derived from a universe of non-callable corporate bonds rated Aa quality or higher. After the bond portfolio is selected, a single interest rate is determined that equates the present value of the plan’s projected benefit payments discounted at this rate with the market value of the bonds selected.
The average remaining service period of active covered employees is 13 years for Duke Energy and Progress Energy, nine years for Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana, 12 years for Duke Energy Progress and 17 years for Duke Energy Florida.
The following tables present the assumptions used for pension benefit accounting.
		December 31,
		2014			2013			2012(a)
Benefit Obligations
Discount rate		4.1	%		4.7	%					4.10%
Salary increase		4.4	%		4.4	%					4.30%
Net Periodic Benefit Cost
Discount rate		4.7	%		4.1	%		4.6	%	-	5.10%
Salary increase		4.4	%		4.3	%					4.40%
(a)	For Progress Energy plans, the assumptions used in 2012 to determine net periodic pension costs reflect remeasurement as of July 1, 2012, due to the merger between Duke Energy and Progress Energy.
Expected Benefit Payments
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Years ending December 31,
2015	$	28		$	2		$	8		$	3		$	4		$	—		$	—
2016	27			2			8			3			4			—			—
2017	27			2			8			3			4			—			—
2018	24			2			8			3			4			—			—
2019	24			2			8			3			4			—			—
2020 - 2024	116			6			38			13			19			2			2
Other Post-Retirement Benefit Plans
Duke Energy provides, and the Subsidiary Registrants participate in, some health care and life insurance benefits for retired employees on a contributory and non-contributory basis. Employees are eligible for these benefits if they have met age and service requirements at retirement, as defined in the plans. The health care benefits include medical, dental, and prescription drug coverage and are subject to certain limitations, such as deductibles and co-payments.
Duke Energy did not make any pre-funding contributions to its other post-retirement benefit plans during the years ended December 31, 2014, 2013 or 2012.
Components of Net Periodic Other Post-Retirement Benefit Costs
	Year Ended December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Service cost	$	10			$	2			$	4			$	1			$	3			$	—		$	1
Interest cost on accumulated post-retirement benefit obligation	49				12				22				11				12				2			5
Expected return on plan assets	(13		)		(9		)		—				—				—				—			(1		)
Amortization of actuarial loss (gain)	39				3				42				31				10				(2		)	—
Amortization of prior service credit	(125		)		(11		)		(95		)		(73		)		(21		)		—			—
Net periodic post-retirement benefit costs	$	(40	)		$	(3	)		$	(27	)		$	(30	)		$	4			$	—		$	5
	Year Ended December 31, 2013
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Service cost	$	24			$	2			$	18			$	9			$	7			$	1		$	1
Interest cost on accumulated post-retirement benefit obligation	68				13				41				22				16				2			5
Expected return on plan assets	(14		)		(11		)		—				—				—				(1		)	(1		)
Amortization of actuarial loss (gain)	52				3				57				34				16				(1		)	1
Amortization of prior service credit	(41		)		(7		)		(30		)		(20		)		(6		)		(1		)	—
Net periodic post-retirement benefit costs	$	89			$	—			$	86			$	45			$	33			$	—		$	6
	Year Ended December 31, 2012
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Service cost	$	16			$	2			$	17			$	8			$	7			$	1		$	1
Interest cost on accumulated post-retirement benefit obligation	56				15				43				23				18				3			6
Expected return on plan assets	(17		)		(10		)		(2		)		—				(2		)		(1		)	(1		)
Amortization of actuarial loss (gain)	14				3				35				20				12				(2		)	—
Amortization of prior service credit	(8		)		(5		)		—				—				—				(1		)	—
Amortization of net transition liability	10				7				4				—				3				—			—
Special termination benefit cost	9				1				5				2				1				—			—
Net periodic post-retirement benefit costs	$	80			$	13			$	102			$	53			$	39			$	—		$	6
Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities
	Year Ended December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Regulatory assets, net increase (decrease)	$	162			$	34			$	129			$	97			$	(4	)		$	—		$	(7	)
Regulatory liabilities, net increase (decrease)	$	249			$	76			$	122			$	61			$	61			$	(2	)	$	14
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	1			$	—			$	1			$	—			$	—			$	—		$	—
Actuarial losses (gains) arising during the year	1				—				(2		)		—				—				—			—
Prior year service credit arising during the year	(6		)		—				—				—				—				—			—
Amortization of prior year prior service credit	2				—				—				—				—				—			—
Net amount recognized in accumulated other comprehensive income	$	(2	)		$	—			$	(1	)		$	—			$	—			$	—		$	—
	Year Ended December 31, 2013
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Regulatory assets, net (decrease) increase	$	(683	)		$	(51	)		$	(634	)		$	(388	)		$	(166	)		$	—		$	(6	)
Regulatory liabilities, net increase (decrease)	$	30			$	—			$	—			$	—			$	—			$	3		$	9
Accumulated other comprehensive (income) loss
Deferred income tax benefit	$	2			$	—			$	—			$	—			$	—			$	—		$	—
Actuarial gains arising during the year	(4		)		—				—				—				—				—			—
Prior year service credit arising during the year	(3		)		—				—				—				—				—			—
Amortization of prior year actuarial loss	1				—				—				—				—				—			—
Net amount recognized in accumulated other comprehensive income	$	(4	)		$	—			$	—			$	—			$	—			$	—		$	—
Reconciliation of Funded Status to Accrued Other Post-Retirement Benefit Costs
	Year Ended December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Change in Projected Benefit Obligation
Accumulated post-retirement benefit obligation at prior measurement date	$	1,106			$	265			$	533			$	233			$	253			$	42		$	118
Service cost	10				2				4				1				3				—			1
Interest cost	49				12				22				11				12				2			5
Plan participants' contributions	25				10				8				4				4				—			2
Actuarial gains(a)	(87		)		(35		)		(19		)		(21		)		—				—			(20		)
Transfers	—				1				(48		)		(2		)		—				(1		)	—
Plan amendments	(85		)		(4		)		(77		)		—				(78		)		(1		)	—
Benefits paid	(103		)		(31		)		(44		)		(19		)		(24		)		(3		)	(10		)
Accrued retiree drug subsidy	1				—				—				—				—				—			—
Accumulated post-retirement benefit obligation at measurement date	$	916			$	220			$	379			$	207			$	170			$	39		$	96
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	214			$	143			—				—				—				$	8		$	18
Actual return on plan assets	18				12				—				—				—				—			2
Benefits paid	(103		)		(31		)		(44		)		(19		)		(24		)		(3		)	(10		)
Transfers	—				(1		)		—				—				—				—			—
Employer contributions	73				12				36				14				20				3			11
Plan participants' contributions	25				10				8				4				4				—			2
Plan assets at measurement date	$	227			$	145			$	—			$	(1	)		$	—			$	8		$	23
(a)	Includes an increase in benefit obligation of $7 million as a result of changes in Duke Energy's mortality assumptions.
	Year Ended December 31, 2013
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Change in Projected Benefit Obligation
Accumulated post-retirement benefit obligation at prior measurement date	$	1,794			$	316			$	1,128			$	612			$	413			$	48		$	136
Service cost	24				2				18				9				7				1			1
Interest cost	68				13				41				22				16				2			5
Plan participants' contributions	47				15				14				6				7				3			3
Actuarial gains	(227		)		(32		)		(156		)		(73		)		(70		)		(6		)	(12		)
Transfers	—				—				(1		)		(8		)		—				—			—
Plan amendments	(476		)		(16		)		(455		)		(311		)		(91		)		—			(3		)
Benefits paid	(132		)		(36		)		(60		)		(26		)		(31		)		(6		)	(14		)
Accrued retiree drug subsidy	8				3				4				2				2				—			2
Accumulated post-retirement benefit obligation at measurement date	$	1,106			$	265			$	533			$	233			$	253			$	42		$	118
Change in Fair Value of Plan Assets
Plan assets at prior measurement date	$	198			$	134			$	—			$	—			$	—			$	7		$	17
Actual return on plan assets	18				13				—				—				—				2			2
Benefits paid	(132		)		(36		)		(60		)		(26		)		(31		)		(6		)	(14		)
Transfers	—				(1		)		—				—				—				—			—
Employer contributions	83				18				46				20				24				2			10
Plan participants' contributions	47				15				14				6				7				3			3
Plan assets at measurement date	$	214			$	143			$	—			$	—			$	—			$	8		$	18
Amounts Recognized in the Consolidated Balance Sheets
	December 31, 2014
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Current post-retirement liability(a)	$	35			$	—			$	29			$	16			$	14			$	2		$	—
Non-current post-retirement liability(b)	654				75				350				192				156				29			73
Total accrued post-retirement liability	$	689			$	75			$	379			$	208			$	170			$	31		$	73
Regulatory assets	$	—			$	—			$	—			$	—			$	—			$	—		$	64
Regulatory liabilities	$	380			$	76			$	122			$	61			$	61			$	19		$	91
Accumulated other comprehensive (income) loss
Deferred income tax liability	$	5			$	—			$	1			$	—			$	—			$	—		$	—
Prior service credit	(9		)		—				—				—				—				—			—
Net actuarial gain	(5		)		—				(2		)		—				—				—			—
Net amounts recognized in accumulated other comprehensive income	$	(9	)		$	—			$	(1	)		$	—			$	—			$	—		$	—
Amounts to be recognized in net periodic pension expense in the next year
Unrecognized net actuarial loss (gain)	$	16			$	(1	)		$	28			$	18			$	10			$	(2	)	$	—
Unrecognized prior service credit	(140		)		(14		)		(103		)		(68		)		(35		)		—			—
	December 31, 2013
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Current post-retirement liability(a)	$	39			$	—			$	36			$	17			$	16			$	2		$	—
Non-current post-retirement liability(b)	853				122				497				216				237				32			100
Total accrued post-retirement liability	$	892			$	122			$	533			$	233			$	253			$	34		$	100
Regulatory assets	$	(162	)		$	(34	)		$	(129	)		$	(97	)		$	4			$	—		$	71
Regulatory liabilities	$	131			$	—			$	—			$	—			$	—			$	21		$	77
Accumulated other comprehensive (income) loss
Deferred income tax liability	$	4			$	—			$	—			$	—			$	—			$	—		$	—
Prior service credit	(5		)		—				—				—				—				—			—
Net actuarial gain	(6		)		—				—				—				—				—			—
Net amounts recognized in accumulated other comprehensive income	$	(7	)		$	—			$	—			$	—			$	—			$	—		$	—
(a)	Included in Other within Current Liabilities on the Consolidated Balance Sheets.
(b)	Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.
Assumptions Used for Other Post-Retirement Benefits Accounting
The discount rate used to determine the current year other post-retirement benefits obligation and following year’s other post-retirement benefits expense is based on a bond selection-settlement portfolio approach. This approach develops a discount rate by selecting a portfolio of high quality corporate bonds that generate sufficient cash flow to provide for projected benefit payments of the plan. The selected bond portfolio is derived from a universe of non-callable corporate bonds rated Aa quality or higher. After the bond portfolio is selected, a single interest rate is determined that equates present value of the plan’s projected benefit payments discounted at this rate with the market value of the bonds selected.
The following tables present the assumptions used for other post-retirement benefits accounting.
		December 31,
		2014			2013			2012(a)
Benefit Obligations
Discount rate		4.1	%		4.7	%					4.1	%
Net Periodic Benefit Cost
Discount rate		4.7	%		4.1	%		4.6	%	-	5.1	%
Expected long-term rate of return on plan assets		6.75	%		7.75	%		5	%	-	8	%
Assumed tax rate		35	%		35	%					35	%
(a)	For Progress Energy plans, the assumptions used in 2012 to determine net periodic post-retirement benefit costs reflect remeasurement as of July 1, 2012, due to the merger between Duke Energy and Progress Energy.
Assumed Health Care Cost Trend Rate
	December 31,
	2014			2013
Health care cost trend rate assumed for next year	6.75	%		8.5	%
Rate to which the cost trend is assumed to decline (the ultimate trend rate)	4.75	%		5	%
Year that rate reaches ultimate trend	2023			2021
Sensitivity to Changes in Assumed Health Care Cost Trend Rates
	Year Ended December 31, 2014
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
1-Percentage Point Increase
Effect on total service and interest costs	$	2		$	1		$	1		$	—		$	1		$	—		$	—
Effect on post-retirement benefit obligation	36			9			15			8			7			2			4
1-Percentage Point Decrease
Effect on total service and interest costs	(2		)	(1		)	(1		)	—			(1		)	—			—
Effect on post-retirement benefit obligation	(31		)	(8		)	(13		)	(7		)	(6		)	(1		)	(3		)
Expected Benefit Payments
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Years ending December 31,
2015	$	77		$	17		$	30		$	16		$	14		$	4		$	10
2016	77			18			30			16			14			4			10
2017	76			18			29			15			14			3			9
2018	74			19			29			15			14			3			9
2019	73			19			29			15			13			3			8
2020 - 2024	332			84			132			70			61			15			35
PLAN ASSETS
Description and Allocations
Duke Energy Master Retirement Trust
Assets for both the qualified pension and other post-retirement benefits are maintained in the Duke Energy Master Retirement Trust. Approximately 98 percent of the Duke Energy Master Retirement Trust assets were allocated to qualified pension plans and approximately 2 percent were allocated to other post-retirement plans, as of December 31, 2014 and 2013. The investment objective of the Duke Energy Master Retirement Trust is to achieve reasonable returns, subject to a prudent level of portfolio risk, for the purpose of enhancing the security of benefits for plan participants.
The asset allocation targets were set after considering the investment objective and the risk profile. Equity securities are held for their higher expected return. Debt securities are primarily held to hedge qualified pension plan liability. Hedge funds, real estate and other global securities are held for diversification. Investments within asset classes are to be diversified to achieve broad market participation and reduce the impact of individual managers or investments.
In 2013, Duke Energy adopted a de-risking investment strategy for the Duke Energy Master Retirement Trust. As the funded status of the qualified pension plans increases, the targeted allocation to return seeking assets will be reduced and the targeted allocation to fixed-income assets will be increased to better manage Duke Energy’s qualified pension liability and reduced funded status volatility. Duke Energy regularly reviews its actual asset allocation and periodically rebalances its investments to the targeted allocation when considered appropriate.
The Duke Energy Retirement Master Trust is authorized to engage in the lending of certain plan assets. Securities lending is an investment management enhancement that utilizes certain existing securities of the Duke Energy Retirement Master Trust to earn additional income. Securities lending involves the loaning of securities to approved parties. In return for the loaned securities, the Duke Energy Retirement Master Trust receives collateral in the form of cash as a safeguard against possible default of any borrower on the return of the loan under terms that permit the Duke Energy Retirement Master Trust to sell the securities. The Master Trust mitigates credit risk associated with securities lending arrangements by monitoring the fair value of the securities loaned, with additional collateral obtained or refunded as necessary. The fair value of securities on loan was approximately $383 million and $43 million at December 31, 2014 and 2013, respectively. Cash obtained as collateral exceeded the fair value of the securities loaned at December 31, 2014 and 2013, respectively. Securities lending income earned by the Master Trust was immaterial for the years ended December 31, 2014, 2013 and 2012, respectively.
Qualified pension and other post-retirement benefits for the Subsidiary Registrants are derived from the Duke Energy Master Retirement Trust, as such, each are allocated their proportionate share of the assets discussed below.
The following table includes the target asset allocations by asset class at December 31, 2014 and the actual asset allocations for the Duke Energy Master Retirement Trust.
				Actual Allocation at December 31,
	Target Allocation			2014			2013
U.S. equity securities	10	%		10	%		10	%
Non-U.S. equity securities	8	%		8	%		8	%
Global equity securities	10	%		10	%		10	%
Global private equity securities	3	%		3	%		3	%
Debt securities	63	%		63	%		63	%
Hedge funds	2	%		3	%		3	%
Real estate and cash	2	%		1	%		1	%
Other global securities	2	%		2	%		2	%
Total	100	%		100	%		100	%
VEBA I
Duke Energy also invests other post-retirement assets in the Duke Energy Corporation Employee Benefits Trust (VEBA I). The investment objective of VEBA I is to achieve sufficient returns, subject to a prudent level of portfolio risk, for the purpose of promoting the security of plan benefits for participants. VEBA I is passively managed.
The following table presents target and actual asset allocations for VEBA I at December 31, 2014.
				Actual Allocation at December 31,
	Target Allocation			2014			2013
U.S. equity securities	30	%		29	%		29	%
Debt securities	45	%		28	%		29	%
Cash	25	%		43	%		42	%
Total	100	%		100	%		100	%
Fair Value Measurements
Duke Energy classifies recurring and non-recurring fair value measurements based on the fair value hierarchy as discussed in Note 16.
Valuation methods of the primary fair value measurements disclosed above are as follows:
Investments in equity securities
Investments in equity securities, other than those accounted for as equity and cost method investments, are typically valued at the closing price in the principal active market as of the last business day of the reporting period. Principal active markets for equity prices include published exchanges such as NASDAQ and NYSE. Foreign equity prices are translated from their trading currency using the currency exchange rate in effect at the close of the principal active market. Prices have not been adjusted to reflect after-hours market activity. The majority of investments in equity securities are valued using Level 1 measurements. When (i) the Duke Energy Registrants lack the ability to redeem investments valued on a net asset value per share basis in the near future or (ii) net asset value per share is not available at the measurement date, the fair value measurement of the investment is categorized as Level 3.
Investments in debt securities
Most debt investments are valued based on a calculation using interest rate curves and credit spreads applied to the terms of the debt instrument (maturity and coupon interest rate) and consider the counterparty credit rating. Most debt valuations are Level 2 measurements. If the market for a particular fixed income security is relatively inactive or illiquid, the measurement is Level 3. U.S. Treasury debt is typically Level 2.
Investments in short-term investment funds
Investments in short-term investment funds are valued at the net asset value of units held at year end. Investments in short-term investment funds with published prices are valued as Level 1. Investments in short-term investment funds with unpublished prices are valued as Level 2.
Investments in real estate limited partnerships
Investments in real estate limited partnerships are valued by the trustee at each valuation date (monthly). As part of the trustee’s valuation process, properties are externally appraised generally on an annual basis, conducted by reputable, independent appraisal firms, and signed by appraisers that are members of the Appraisal Institute, with the professional designation MAI. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There are three valuation techniques that can be used to value investments in real estate assets: the market, income or cost approach. The appropriateness of each valuation technique depends on the type of asset or business being valued. In addition, the trustee may cause additional appraisals to be performed as warranted by specific asset or market conditions. Property valuations and the salient valuation-sensitive assumptions of each direct investment property are reviewed by the trustee quarterly and values are adjusted if there has been a significant change in circumstances related to the investment property since the last valuation. Value adjustments for interim capital expenditures are only recognized to the extent that the valuation process acknowledges a corresponding increase in fair value. An independent firm is hired to review and approve quarterly direct real estate valuations. Key inputs and assumptions used to determine fair value includes among others, rental revenue and expense amounts and related revenue and expense growth rates, terminal capitalization rates and discount rates. Development investments are valued using cost incurred to date as a primary input until substantive progress is achieved in terms of mitigating construction and leasing risk at which point a discounted cash flow approach is more heavily weighted. Key inputs and assumptions in addition to those noted above used to determine the fair value of development investments include construction costs, and the status of construction completion and leasing. Investments in real estate limited partnerships are valued as Level 3.
Duke Energy Master Retirement Trust
The following tables provide the fair value measurement amounts for the Duke Energy Master Retirement Trust qualified pension and other post-retirement assets.
	December 31, 2014
(in millions)	Total Fair Value				Level 1				Level 2				Level 3
Equity securities	$	2,346			$	1,625			$	721			$	—
Corporate debt securities	4,349				—				4,348				1
Short-term investment funds	333				171				162				—
Partnership interests	298				—				—				298
Hedge funds	146				—				146				—
Real estate limited partnerships	104				—				—				104
U.S. government securities	917				—				916				1
Guaranteed investment contracts	32				—				—				32
Governments bonds - foreign	44				—				44				—
Cash	30				30				—				—
Government and commercial mortgage backed securities	9				—				9				—
Net pending transactions and other investments	10				(10		)		20				—
Total assets(a)	$	8,618			$	1,816			$	6,366			$	436
(a)	Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio and Duke Energy Indiana were allocated approximately 28 percent, 31 percent, 15 percent, 16 percent, 5 percent and 8 percent, respectively, of the Duke Energy Master Retirement Trust assets at December 31, 2014. Accordingly, all Level 1, 2 and 3 amounts included in the table above are allocable to the Subsidiary Registrants using these percentages.
	December 31, 2013
(in millions)	Total Fair Value				Level 1				Level 2				Level 3
Equity securities	$	2,877			$	1,801			$	1,022			$	54
Corporate debt securities	2,604				—				2,601				3
Short-term investment funds	1,158				254				904				—
Partnership interests	307				—				—				307
Hedge funds	164				—				111				53
Real estate limited partnerships	95				—				—				95
U.S. government securities	927				—				927				—
Guarantees investment contracts	33				—				—				33
Governments bonds - foreign	19				—				18				1
Cash	58				58				—				—
Asset backed securities	7				—				7				—
Net pending transactions and other investments	12				7				5				—
Total assets(a)	$	8,261			$	2,120			$	5,595			$	546
(a)	Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio and Duke Energy Indiana were allocated approximately 28 percent, 35 percent, 16 percent, 16 percent, 5 percent and 8 percent, respectively, of the Duke Energy Master Retirement Trust assets at December 31, 2013. Accordingly, all Level 1, 2 and 3 amounts included in the table above are allocable to the Subsidiary Registrants using these percentages.
The following table provides a reconciliation of beginning and ending balances of assets of master trusts measured at fair value on a recurring basis where the determination of fair value includes significant unobservable inputs (Level 3).
(in millions)	2014				2013
Balance at January 1	$	546			$	352
Combination of trust assets(a)	—				288
Purchases, sales, issuances and settlements
Purchases	17				25
Sales	(164		)		(152		)
Total gains (losses) and other, net	37				33
Balance at December 31	$	436			$	546
(a)	As of January 1, 2013, assets previously held in the Progress Energy Master Retirement Trust were transferred into the Duke Energy Master Retirement Trust.
VEBA I
The following tables provide the fair value measurement amounts for VEBA I other post-retirement assets.
	December 31, 2014
(in millions)	Total Fair Value				Level 1			Level 2				Level 3
Cash and cash equivalents	$	21			—			$	21			—
Equity securities	14				—			14				—
Debt securities	13				—			13				—
Total assets	$	48			—			$	48			—
	December 31, 2013
(in millions)	Total Fair Value				Level 1			Level 2				Level 3
Cash and cash equivalents	$	21			—			$	21			—
Equity securities	15				—			15				—
Debt securities	15				—			15				—
Total assets	$	51			—			$	51			—
EMPLOYEE SAVINGS PLANS
Duke Energy sponsors, and the Subsidiary Registrants participate in, employee savings plans that cover substantially all U.S. employees. Most employees participate in a matching contribution formula where Duke Energy provides a matching contribution generally equal to 100 percent of employee before-tax and Roth 401(k) contributions, and, as applicable, after-tax contributions, of up to 6 percent of eligible pay per pay period. Dividends on Duke Energy shares held by the savings plans are charged to retained earnings when declared and shares held in the plans are considered outstanding in the calculation of basic and diluted earnings per share.
As of January 1, 2014, for new and rehired non-union and certain unionized employees who are not eligible to participate in Duke Energy’s defined benefit plans, an additional employer contribution of 4 percent of eligible pay per pay period, which is subject to a three-year vesting schedule, is provided to the employee’s savings plan account.
The following table includes pretax employer matching contributions made by Duke Energy and expensed by the Subsidiary Registrants.
(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
Years ended December 31,
2014(a)	$	143			$	47			$	43			$	30			$	14			$	3		$	7
2013	134				45				45				25				14				3			7
2012	107				37				45				24				15				4			6
(a)	For 2014, amounts include the additional employer contribution of 4 percent of eligible pay per pay period for employees not eligible to participate in a defined benefit plan.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	Income Tax Expense
	Components of Income Tax Expense
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Current income taxes
	Federal	$	—		$	161		$	(466	)	$	(184	)	$	(53	)	$	(73	)	$	(112	)
	State	56			51			(8		)	14			1			3			1
	Foreign	144			—			—			—			—			—			—
	Total current income taxes	200			212			(474		)	(170		)	(52		)	(70		)	(111		)
	Deferred income taxes
	Federal	1,517			407			938			436			350			113			294
	State	35			(25		)	84			25			52			1			15
	Foreign	(67		)	—			—			—			—			—			—
	Total deferred income taxes(a)(b)	1,485			382			1,022			461			402			114			309
	Investment tax credit amortization	(16		)	(6		)	(8		)	(6		)	(1		)	(1		)	(1		)
	Income tax expense from continuing operations	1,669			588			540			285			349			43			197
	Tax benefit from discontinued operations	(295		)	—			(4		)	—			—			(300		)	—
	Total income tax expense included in Consolidated Statements of Operations	$	1,374		$	588		$	536		$	285		$	349		$	(257	)	$	197
	(a)	There were no benefits of net operating loss (NOL) carryforwards.
	(b)	Includes utilization of NOL and tax credit carryforwards of $1,544 million at Duke Energy, $345 million at Duke Energy Carolinas, $530 million at Progress Energy, $291 million at Duke Energy Progress, $64 million at Duke Energy Florida, $56 million at Duke Energy Ohio and $141 million at Duke Energy Indiana.
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Current income taxes
	Federal	$	(141	)	$	49		$	(221	)	$	(70	)	$	(143	)	$	(24	)	$	(88	)
	State	(40		)	11			(37		)	(10		)	(13		)	(4		)	7
	Foreign	151			—			—			—			—			—			—
	Total current income taxes	(30		)	60			(258		)	(80		)	(156		)	(28		)	(81		)
	Deferred income taxes
	Federal	1,092			464			555			316			326			65			276
	State	144			75			84			59			44			6			29
	Foreign	14			—			—			—			—			—			—
	Total deferred income taxes(a)	1,250			539			639			375			370			71			305
	Investment tax credit amortization	(15		)	(5		)	(8		)	(7		)	(1		)	—			(1		)
	Income tax expense from continuing operations	1,205			594			373			288			213			43			223
	Tax expense from discontinued operations	29			—			(26		)	—			—			32			—
	Total income tax expense included in Consolidated Statements of Operations	$	1,234		$	594		$	347		$	288		$	213		$	75		$	223
	(a)	Includes benefits of NOL carryforwards of $808 million at Duke Energy, $458 million at Progress Energy, $64 million at Duke Energy Progress, $301 million at Duke Energy Florida and $179 million at Duke Energy Indiana.
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Current income taxes
	Federal	$	(108	)	$	(1	)	$	(88	)	$	(48	)	$	6		$	(8	)	$	(27	)
	State	29			(25		)	2			(6		)	—			5			27
	Foreign	133			—			—			—			—			—			—
	Total current income taxes	54			(26		)	(86		)	(54		)	6			(3		)	—
	Deferred income taxes
	Federal	491			408			226			162			121			40			(47		)
	State	71			77			40			9			21			(2		)	(25		)
	Foreign	20			—			—			—			—			—			—
	Total deferred income taxes(a)	582			485			266			171			142			38			(72		)
	Investment tax credit amortization	(13		)	(6		)	(8		)	(7		)	(1		)	(2		)	(1		)
	Income tax expense (benefit) from continuing operations	623			453			172			110			147			33			(73		)
	Tax benefit from discontinued operations	107			—			29			—			—			65			—
	Total income tax expense (benefit) included in Consolidated Statements of Operations	$	730		$	453		$	201		$	110		$	147		$	98		$	(73	)
	(a)	Includes benefits of NOL carryforwards of $1,062 million at Duke Energy, $245 million at Duke Energy Carolinas, $357 million at Progress Energy, $257 million at Duke Energy Progress, $25 million at Duke Energy Florida, $34 million at Duke Energy Ohio and $205 million at Duke Energy Indiana.
	Duke Energy Income from Continuing Operations before Income Taxes
		Years Ended December 31,
	(in millions)	2014				2013				2012
Domestic	$	3,600			$	3,183			$	1,600
Foreign	534				612				634
Income from continuing operations before income taxes	$	4,134			$	3,795			$	2,234
Statutory Rate Reconciliation
The following tables present a reconciliation of income tax expense at the U.S. federal statutory tax rate to the actual tax expense from continuing operations.
	Year Ended December 31, 2014
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy			Energy			Energy			Energy
				Carolinas						Progress			Florida			Ohio			Indiana
Income tax expense, computed at the statutory rate of 35 percent	$	1,447		$	581		$	497		$	263		$	314		$	39		$	195
State income tax, net of federal income tax effect	59			17			49			25			34			3			10
Tax differential on foreign earnings(a)	(110		)	—			—			—			—			—			—
AFUDC equity income	(47		)	(32		)	(9		)	(9		)	—			(1		)	(5		)
Renewable energy production tax credits	(67		)	—			—			—			—			—			—
International tax dividend	373			—			—			—			—			—			—
Other items, net	14			22			3			6			1			2			(3		)
Income tax expense from continuing operations	$	1,669		$	588		$	540		$	285		$	349		$	43		$	197
Effective tax rate	40.4		%	35.4		%	38		%	37.9		%	38.9		%	38.9		%	35.5		%
(a)	Includes a $57 million benefit as a result of the merger of two Chilean subsidiaries and a change in income tax rates in various countries primarily relating to Peru.
During the fourth quarter of 2014, Duke Energy declared a taxable dividend of foreign earnings in the form of notes payable that will result in the repatriation of approximately $2.7 billion of cash held and expected to be generated by International Energy over a period of up to 8 years. As a result of the decision to repatriate all cumulative historical undistributed foreign earnings, during the fourth quarter of 2014, Duke Energy recorded U.S. income tax expense of approximately $373 million. Duke Energy’s intention is to indefinitely reinvest prospective undistributed earnings generated by Duke Energy's foreign subsidiaries, and accordingly U.S. deferred taxes will not be provided for those earnings.
	Year Ended December 31, 2013
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy			Energy			Energy			Energy
				Carolinas						Progress			Florida			Ohio			Indiana
Income tax expense, computed at the statutory rate of 35 percent	$	1,328		$	549		$	361		$	276		$	188		$	39		$	203
State income tax, net of federal income tax effect	66			56			31			31			20			2			23
Tax differential on foreign earnings	(49		)	—			—			—			—			—			—
AFUDC equity income	(55		)	(32		)	(18		)	(15		)	(3		)	—			(5		)
Renewable energy production tax credits	(62		)	—			—			—			—			—			—
Other items, net	(23		)	21			(1		)	(4		)	8			2			2
Income tax expense (benefit) from continuing operations	$	1,205		$	594		$	373		$	288		$	213		$	43		$	223
Effective tax rate	31.8		%	37.8		%	36.2		%	36.5		%	39.6		%	39.1		%	38.4		%
	Year Ended December 31, 2012
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy			Energy			Energy			Energy
				Carolinas						Progress			Florida			Ohio			Indiana
Income tax expense, computed at the statutory rate of 35 percent	$	782		$	461		$	185		$	134		$	145		$	27		$	(43	)
State income tax, net of federal income tax effect	65			34			33			1			14			2			1
Tax differential on foreign earnings	(69		)	—			—			—			—			—			—
AFUDC equity income	(101		)	(54		)	(37		)	(24		)	(13		)	(2		)	(26		)
Renewable energy production tax credits	(25		)	—			—			—			—			—			—
Other items, net	(29		)	12			(9		)	(1		)	1			6			(5		)
Income tax expense from continuing operations	$	623		$	453		$	172		$	110		$	147		$	33		$	(73	)
Effective tax rate	27.9		%	34.3		%	32.7		%	28.7		%	35.7		%	42.9		%	59.5		%
Valuation allowances have been established for certain foreign and state NOL carryforwards and state income tax credits that reduce deferred tax assets to an amount that will be realized on a more-likely-than-not basis. The net change in the total valuation allowance is included in Tax differential on foreign earnings and State income tax, net of federal income tax effect in the above tables.
DEFERRED TAXES
Net Deferred Income Tax Liability Components
	December 31, 2014
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy			Energy			Energy			Energy
				Carolinas						Progress			Florida			Ohio			Indiana
Deferred credits and other liabilities	$	188		$	53		$	108		$	28		$	78		$	(8	)	$	12
Capital lease obligations	63			10			—			—			—			—			2
Pension, postretirement and other employee benefits	546			4			188			96			93			17			43
Progress Energy merger purchase accounting adjustments(a)	1,124			—			—			—			—			—			—
Tax credits and NOL carryforwards	3,540			157			980			91			252			38			260
Investments and other assets	—			—			—			—			—			14			—
Other	—			12			—			55			—			35			11
Valuation allowance	(184		)	—			(13		)	(1		)	—			—			—
Total deferred income tax assets	5,277			236			1,263			269			423			96			328
Investments and other assets	(1,625		)	(1,051		)	(427		)	(232		)	(245		)	—			(4		)
Accelerated depreciation rates	(11,715		)	(4,046		)	(3,284		)	(2,030		)	(1,252		)	(1,660		)	(1,603		)
Regulatory assets and deferred debits	(3,694		)	(953		)	(1,602		)	(809		)	(792		)	(141		)	(106		)
Other	(44		)	—			(151		)	—			(246		)	—			—
Total deferred income tax liabilities	(17,078		)	(6,050		)	(5,464		)	(3,071		)	(2,535		)	(1,801		)	(1,713		)
Net deferred income tax liabilities	$	(11,801	)	$	(5,814	)	$	(4,201	)	$	(2,802	)	$	(2,112	)	$	(1,705	)	$	(1,385	)
(a)	Primarily related to capital lease obligations and debt fair value adjustments.
On July 23, 2013, HB 998 was signed into law. HB 998 reduces the North Carolina corporate income tax rate from a statutory 6.9 percent to 6.0 percent in January 2014 with a further reduction to 5.0 percent in January 2015. Duke Energy recorded a net reduction of approximately $145 million to its North Carolina deferred tax liability in the third quarter of 2013. The significant majority of this deferred tax liability reduction was offset by recording a regulatory liability pending NCUC determination of the disposition of the amounts related to Duke Energy Carolinas and Duke Energy Progress. The impact of HB 998 did not have a significant impact on the financial position, results of operation, or cash flows of Duke Energy, Duke Energy Carolinas, Progress Energy or Duke Energy Progress.
The following table presents the expiration of tax credits and NOL carryforwards.
	December 31, 2014
(in millions)	Amount				Expiration Year
Investment tax credits	$	581			2029		—		2034
Alternative minimum tax credits	1,093				Indefinite
Federal NOL carryforwards	749				2030		—		2033
State NOL carryforwards and credits(a)	162				2015		—		2034
Foreign NOL carryforwards(b)	117				2015		—		2033
Foreign Tax Credits	838				2024
Total tax credits and NOL carryforwards	$	3,540
(a)	A valuation allowance of $79 million has been recorded on the state Net Operating Loss carryforwards, as presented in the Net Deferred Income Tax Liability Components table.
(b)	A valuation allowance of $105 million has been recorded on the foreign Net Operating Loss carryforwards, as presented in the Net Deferred Income Tax Liability Components table.
	December 31, 2013
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy			Energy			Energy			Energy
				Carolinas						Progress			Florida			Ohio			Indiana
Deferred credits and other liabilities	$	245		$	56		$	136		$	9		$	96		$	(13	)	$	9
Capital lease obligations	59			11			—			—			—			—			(2		)
Pension, postretirement and other employee benefits	649			18			341			119			145			23			54
Progress Energy merger purchase accounting adjustments(a)	1,184			—			—			—			—			—			—
Tax credits and NOL carryforwards	4,307			488			1,965			396			365			165			521
Other	265			15			116			39			43			20			14
Valuation allowance	(192		)	—			(40		)	(1		)	—			—			—
Total deferred income tax assets	6,517			588			2,518			562			649			195			596
Investments and other assets	(1,396		)	(999		)	(209		)	(160		)	(49		)	(17		)	(7		)
Accelerated depreciation rates	(12,615		)	(4,400		)	(3,663		)	(2,528		)	(1,160		)	(1,937		)	(1,591		)
Regulatory assets and deferred debits	(3,185		)	(609		)	(1,389		)	(202		)	(1,159		)	(168		)	(117		)
Total deferred income tax liabilities	(17,196		)	(6,008		)	(5,261		)	(2,890		)	(2,368		)	(2,122		)	(1,715		)
Net deferred income tax liabilities	$	(10,679	)	$	(5,420	)	$	(2,743	)	$	(2,328	)	$	(1,719	)	$	(1,927	)	$	(1,119	)
(a)	Primarily related to capital lease obligations and debt fair value adjustments.
Classification of Deferred Tax Assets (Liabilities) in the Consolidated Balance Sheets
	December 31, 2014
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy Progress			Energy Florida			Energy			Energy
				Carolinas												Ohio			Indiana
Current Assets: Other	$	1,593		$	3		$	558		$	106		$	340		$	60		$	206
Investments and Other Assets: Other	29			—			—			—			—			—			—
Current Liabilities: Other	—			(5		)	—			—			—			—			—
Deferred Credits and Other Liabilities: Other	(13,423		)	(5,812		)	(4,759		)	(2,908		)	(2,452		)	(1,765		)	(1,591		)
Net deferred income tax liabilities	$	(11,801	)	$	(5,814	)	$	(4,201	)	$	(2,802	)	$	(2,112	)	$	(1,705	)	$	(1,385	)
	December 31, 2013
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy Progress			Energy Florida			Energy			Energy
				Carolinas												Ohio			Indiana
Current Assets: Other	$	1,373		$	286		$	540		$	229		$	110		$	85		$	52
Investments and Other Assets: Other	45			—			—			—			—			—			—
Deferred Credits and Other Liabilities: Other	(12,097		)	(5,706		)	(3,283		)	(2,557		)	(1,829		)	(2,012		)	(1,171		)
Net deferred income tax liabilities	$	(10,679	)	$	(5,420	)	$	(2,743	)	$	(2,328	)	$	(1,719	)	$	(1,927	)	$	(1,119	)
UNRECOGNIZED TAX BENEFITS
The following tables present changes to unrecognized tax benefits.
	Year Ended December 31, 2014
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke
				Energy						Energy			Energy			Energy
				Carolinas						Progress			Florida			Indiana
Unrecognized tax benefits — January 1	$	230		$	171		$	32		$	22		$	8		$	1
Unrecognized tax benefits increases (decreases)
Gross increases — tax positions in prior periods	—			—			1			1			—			—
Gross decreases — tax positions in prior periods	(2		)	—			—			—			—			—
Decreases due to settlements	(15		)	(11		)	(1		)	—			—			—
Total changes	(17		)	(11		)	—			1			—			—
Unrecognized tax benefits — December 31	$	213		$	160		$	32		$	23		$	8		$	1
	Year Ended December 31, 2013
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy Progress			Energy Florida			Energy			Energy
				Carolinas												Ohio			Indiana
Unrecognized tax benefits — January 1	$	540		$	271		$	131		$	67		$	44		$	36		$	32
Unrecognized tax benefits (decreases) increases
Gross decreases — tax positions in prior periods	(231		)	(100		)	(86		)	(45		)	(37		)	(36		)	(31		)
Decreases due to settlements	(66		)	—			—			—			—			—			—
Reduction due to lapse of statute of limitations	(13		)	—			(13		)	—			1			—			—
Total changes	(310		)	(100		)	(99		)	(45		)	(36		)	(36		)	(31		)
Unrecognized tax benefits — December 31	$	230		$	171		$	32		$	22		$	8		$	—		$	1
	Year Ended December 31, 2012
(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
				Energy						Energy Progress			Energy Florida			Energy			Energy
				Carolinas												Ohio			Indiana
Unrecognized tax benefits — January 1	$	385		$	260		$	173		$	73		$	80		$	32		$	24
Acquisitions	128			—			—			—			—			—			—
Unrecognized tax benefits increases (decreases)
Gross increases — tax positions in prior periods	29			12			23			10			12			2			6
Gross decreases — tax positions in prior periods	(4		)	—			(72		)	(19		)	(52		)	—			—
Gross increases — current period tax positions	28			15			8			4			4			4			4
Gross decreases — current period tax positions	(9		)	(5		)	(1		)	(1		)	—			(2		)	(2		)
Decreases due to settlements	(13		)	(11		)	—			—			—			—			—
Reduction due to lapse of statute of limitations	(4		)	—			—			—			—			—			—
Total changes	155			11			(42		)	(6		)	(36		)	4			8
Unrecognized tax benefits — December 31	$	540		$	271		$	131		$	67		$	44		$	36		$	32
The following table includes additional information regarding the Duke Energy Registrants' unrecognized tax benefits. It is reasonably possible that Duke Energy and Progress Energy will reflect an approximate $28 million reduction, Duke Energy Progress will reflect an approximate $17 million reduction, and Duke Energy Florida will reflect an approximate $7 million reduction in unrecognized tax benefits within the next 12 months due to the expected lapse of the statute of limitations. All other Duke Energy Registrants do not anticipate a material increase or decrease in unrecognized tax benefits within the next 12 months.
	December 31, 2014
(in millions)	Duke			Duke			Progress Energy			Duke			Duke			Duke
	Energy			Energy						Energy Progress			Energy Florida			Energy
				Carolinas												Indiana
Amount that if recognized, would affect the	$	121		$	112		$	3		$	2		$	2		$	2
effective tax rate or regulatory liability(a)
Amount that if recognized, would be recorded as a component	8			—			—			—			—			—
of discontinued operations
(a)	Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana are unable to estimate the specific amounts that would affect the effective tax rate versus the regulatory liability.
OTHER TAX MATTERS
The following tables include interest recognized in the Consolidated Statements of Operations and the Consolidated Balance Sheets.
	Year Ended December 31, 2014
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
Net interest income recognized related to income taxes	$	6		$	—		$	3		$	—		$	1		$	4		$	4
Net interest expense recognized related to income taxes	—			1			—			1			—			—			—
Interest receivable related to income taxes	—			—			—			—			—			—			2
Interest payable related to income taxes	13			13			5			3			5			—			—
	Year Ended December 31, 2013
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
Net interest income recognized related to income taxes	$	2		$	2		6		7		—		4		$	1
Interest payable related to income taxes	27			8			10		2		7		—		—
	Year Ended December 31, 2012
(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio		Duke Energy Indiana
Net interest income recognized related to income taxes	$	10		$	9		$	—		$	—		$	—		—		2
Net interest expense recognized related to income taxes	—			—			2			—			2			—		—
Interest receivable related to income taxes	—			7			—			—			—			—		—
Interest payable related to income taxes	7			—			17			8			9			3		1
Duke Energy and its subsidiaries are no longer subject to U.S. federal examination for years before 2008. The years 2008 through 2011 are in Appeals. The IRS is currently auditing the federal income tax returns for years 2012 and 2013. With few exceptions, Duke Energy and its subsidiaries are no longer subject to state, local or non-U.S. income tax examinations by tax authorities for years before 2004.

Other_Income_and_Expenses_Net

Other Income and Expenses, Net	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Other Income and Expenses, Net	OTHER INCOME AND EXPENSES, NET
	The components of Other income and expenses, net on the Consolidated Statements of Operations are as follows.
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Interest income	$	57		$	4		$	3	$	—	$	2	$	8		$	6
	Foreign exchange gains	3			—			—		—		—		—			—
	AFUDC equity	135			91			26		25		—		4			14
	Deferred returns	89			71			17		17		—		—			—
	Other income (expense)	67			6			31		9		18		(2		)	2
	Other income and expense, net	$	351		$	172		$	77	$	51	$	20	$	10		$	22
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Interest income	$	26		$	1		$	7	$	1	$	3	$	5		$	6
	Foreign exchange losses	(18		)	—			—		—		—		—			—
	AFUDC equity	157			91			50		42		8		1			15
	Deferred returns	39			32			7		7		—		—			—
	Other income (expense)	58			(4		)	30		7		19		(4		)	(3		)
	Other income and expense, net	$	262		$	120		$	94	$	57	$	30	$	2		$	18
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Interest income	$	50		$	11		$	2	$	1	$	1	$	—		$	7
	Foreign exchange gains	4			—			—		—		—		—			—
	AFUDC equity	300			154			106		69		37		6			84
	Deferred returns	24			24			—		—		—		—			—
	Other income (expense)	19			(4		)	22		9		1		2			(1		)
	Other income and expense, net	$	397		$	185		$	130	$	79	$	39	$	8		$	90

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS
	For information on subsequent events related to acquisitions, dispositions and sales of other assets, regulatory matters, commitments and contingencies, and debt and credit facilities, see Notes 2, 4, 5 and 6.

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	QUARTERLY FINANCIAL DATA (UNAUDITED)
	DUKE ENERGY
	Quarterly EPS amounts are meant to be stand-alone calculations and are not always additive to the full-year amount due to rounding and the weighting of share issuances.
	(in millions, except per share data)	First			Second			Third			Fourth			Total
		Quarter(a)			Quarter(a)			Quarter(a)			Quarter(a)
	2014
	Operating revenues	$	6,263		$	5,708		$	6,395		$	5,559		$	23,925
	Operating income	1,362			1,289			1,619			988			5,258
	Income from continuing operations	750			725			891			99			2,465
	(Loss) income from discontinued operations, net of tax	(843		)	(112		)	378			1			(576		)
	Net loss (income)	(93		)	613			1,269			100			1,889
	Net loss (income) attributable to Duke Energy Corporation	(97		)	609			1,274			97			1,883
	Earnings per share:
	Income from continuing operations attributable to Duke Energy Corporation common shareholders
	Basic	$	1.05		$	1.02		$	1.25		$	0.14		$	3.46
	Diluted	$	1.05		$	1.02		$	1.25		$	0.14		$	3.46
	(Loss) income from discontinued operations attributable to Duke Energy Corporation common shareholders
	Basic	$	(1.19	)	$	(0.16	)	$	0.55		$	—		$	(0.80	)
	Diluted	$	(1.19	)	$	(0.16	)	$	0.55		$	—		$	(0.80	)
	Net (loss) income attributable to Duke Energy Corporation common shareholders
	Basic	$	(0.14	)	$	0.86		$	1.8		$	0.14		$	2.66
	Diluted	$	(0.14	)	$	0.86		$	1.8		$	0.14		$	2.66
	2013
	Operating revenues	$	5,536		$	5,393		$	6,217		$	5,610		$	22,756
	Operating income	1,259			742			1,660			1,193			4,854
	Income from continuing operations	663			292			946			689			2,590
	(Loss) income from discontinued operations, net of tax	(29		)	50			62			3			86
	Net income	634			342			1,008			692			2,676
	Net income attributable to Duke Energy Corporation	634			339			1,004			688			2,665
	Earnings per share:
	Income from continuing operations attributable to Duke Energy Corporation common shareholders
	Basic	$	0.93		$	0.4		$	1.33		$	0.96		$	3.64
	Diluted	$	0.93		$	0.4		$	1.33		$	0.96		$	3.63
	(Loss) income from discontinued operations attributable to Duke Energy Corporation common shareholders
	Basic	$	(0.04	)	$	0.08		$	0.09		$	0.01		$	0.13
	Diluted	$	(0.04	)	$	0.08		$	0.09		$	0.01		$	0.13
	Net income attributable to Duke Energy Corporation common shareholders
	Basic	$	0.89		$	0.48		$	1.42		$	0.97		$	3.77
	Diluted	$	0.89		$	0.48		$	1.42		$	0.97		$	3.76
	(a)	Operating results reflect reclassifications due to the impact of discontinued operations (see Note 2 for further information).
	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve Progress Energy merger (see Note 2)	$	(55	)	$	(61	)	$	(56	)	$	(33	)	$	(205	)
	Midwest Generation Impairment (see Note 2)	(1,287		)	—			477			(39		)	(849		)
	Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(102		)	(102		)
	International Tax Adjustment (see Note 22)	—			—			—			(373		)	(373		)
	Asset Impairment (see Note 11)	(94		)	—			—			—			(94		)
	Total	$	(1,436	)	$	(61	)	$	421		$	(547	)	$	(1,623	)
	2013(a)
	Costs to achieve Progress Energy merger (see Note 2)	$	(55	)	$	(82	)	$	(88	)	$	(72	)	$	(297	)
	Crystal River Unit 3 charges (see Note 4)	—			(295		)	—			(57		)	(352		)
	Harris and Levy nuclear development charges (see Note 4)	—			(87		)	—			—			(87		)
	Gain on sale of DukeNet (see Note 12)	—			—			—			105			105
	Total	$	(55	)	$	(464	)	$	(88	)	$	(24	)	$	(631	)
	(a)	Revised retail rates became effective in January for Duke Energy Florida, May for Duke Energy Ohio, June for Duke Energy Progress and September for Duke Energy Carolinas (see Note 4 for further information).
	DUKE ENERGY CAROLINAS
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Operating revenues	$	2,000		$	1,755		$	1,938		$	1,658		$	7,351
	Operating income	509			438			630			318			1,895
	Net income	286			270			377			139			1,072
2013
Operating revenues	$	1,729		$	1,591		$	1,919		$	1,715		$	6,954
Operating income	434			351			604			420			1,809
Net income	244			181			342			209			976
The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Costs to achieve Progress Energy merger (see Note 2)	$	(29	)	$	(38	)	$	(25	)	$	(17	)	$	(109	)
Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(72		)	(72		)
Total	(29		)	(38		)	(25		)	(89		)	(181		)
2013(a)
Costs to achieve Progress Energy merger (see Note 2)	$	(22	)	$	(35	)	$	(34	)	$	(29	)	$	(120	)
(a)	Revised retail rates became effective in September in both North Carolina and South Carolina (see Note 4 for further information).
PROGRESS ENERGY
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Operating revenues	$	2,541		$	2,421		$	2,863		$	2,341		$	10,166
Operating income	477			488			665			388			2,018
Income from continuing operations	204			207			330			139			880
Net income	203			202			330			139			874
Net income attributable to Parent	202			202			329			136			869
2013
Operating revenues	$	2,186		$	2,281		$	2,766		$	2,300		$	9,533
Operating income	430			114			671			403			1,618
Income (loss) from continuing operations	154			(13		)	328			190			659
Net income (loss)	154			(17		)	342			196			675
Net income (loss) attributable to Parent	153			(17		)	341			195			672
The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Costs to achieve the merger with Duke Energy (see Note 2)	$	(19	)	$	(12	)	$	(21	)	$	(13	)	$	(65	)
Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(30		)	(30		)
Total	(19		)	(12		)	(21		)	(43		)	(95		)
2013(a)
Costs to achieve the merger with Duke Energy (see Note 2)	$	(19	)	$	(33	)	$	(42	)	$	(28	)	$	(122	)
Crystal River Unit 3 charges (see Note 4)	—			(295		)	—			(57		)	(352		)
Harris and Levy nuclear development charges (see Note 4)	—			(87		)	—			—			(87		)
Total	$	(19	)	$	(415	)	$	(42	)	$	(85	)	$	(561	)
(a)	Revised retail rates became effective in January in Florida and June in North Carolina (see Note 4 for further information).
DUKE ENERGY PROGRESS
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Operating revenues	$	1,422		$	1,191		$	1,367		$	1,196		$	5,176
Operating income	258			212			285			180			935
Net income	133			101			157			76			467
2013
Operating revenues	$	1,216		$	1,135		$	1,430		$	1,211		$	4,992
Operating income	212			166			303			251			932
Net income	110			77			175			138			500
The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Costs to achieve the merger with Duke Energy (see Note 2)	$	(14	)	$	(3	)	$	(15	)	$	(10	)	$	(42	)
Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(30		)	(30		)
Total	(14		)	(3		)	(15		)	(40		)	(72		)
2013(a)
Costs to achieve the merger with Duke Energy (see Note 2)	$	(11	)	$	(22	)	$	(32	)	$	(19	)	$	(84	)
Harris nuclear development charges (see Note 4)	$	—		$	(22	)	$	—		$	—		$	(22	)
Total	$	(11	)	$	(44	)	$	(32	)	$	(19	)	$	(106	)
(a)	Revised retail rates became effective in June in North Carolina (see Note 4 for further information).
DUKE ENERGY FLORIDA
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Operating revenues	$	1,116		$	1,225		$	1,491		$	1,143		$	4,975
Operating income	219			276			378			205			1,078
Net income	108			142			205			93			548
2013
Operating revenues	$	968		$	1,142		$	1,332		$	1,085		$	4,527
Operating income (loss)	221			(53		)	369			151			688
Net income (loss)	110			(57		)	197			75			325
The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Costs to achieve the merger with Duke Energy (see Note 2)	$	(5	)	$	(9	)	$	(6	)	$	(3	)	$	(23	)
2013(a)
Costs to achieve the merger with Duke Energy (see Note 2)	$	(8	)	$	(11	)	$	(10	)	$	(9	)	$	(38	)
Crystal River Unit 3 charges (see Note 4)	—			(295		)	—			(57		)	(352		)
Levy nuclear development charges (see Note 4)	—			(65		)	—			—			(65		)
Total	$	(8	)	$	(371	)	$	(10	)	$	(66	)	$	(455	)
(a)	Revised retail rates became effective in January (see Note 4 for further information).
DUKE ENERGY OHIO
(in millions)	First			Second			Third			Fourth			Total
	Quarter(a)			Quarter(a)			Quarter(a)			Quarter(a)
2014
Operating revenues	$	575		$	412		$	446		$	480		$	1,913
Operating (loss) income	(7		)	62			58			74			187
(Loss) income from discontinued operations, net of tax	(875		)	(135		)	413			34			(563		)
Net (loss) income	(890		)	(108		)	439			64			(495		)
2013
Operating revenues	$	503		$	408		$	438		$	456		$	1,805
Operating income	56			27			50			49			182
(Loss) income from discontinued operations, net of tax	(47		)	51			35			(4		)	35
Net (loss) income	(21		)	58			59			6			102
(a)	Operating results reflect reclassifications due to the impact of discontinued operations (see Note 2 for further information).
The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Costs to achieve Progress Energy merger (see Note 2)	$	(2	)	$	(4	)	$	(3	)	$	(2	)	$	(11	)
Midwest Generation Impairment (see Note 2)	(1,318		)	—			477			(39		)	(880		)
Asset Impairment (see Note 11)	(94		)	—			—			—			(94		)
Total	$	(1,414	)	$	(4	)	$	474		$	(41	)	$	(985	)
2013(a)
Costs to achieve Progress Energy merger (see Note 2)	$	(4	)	$	(4	)	$	(4	)	$	(4	)	$	(16	)
(a)	Revised retail rates became effective in May (see Note 4 for further information).
DUKE ENERGY INDIANA
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Operating revenues	$	845		$	748		$	790		$	792		$	3,175
Operating income	215			178			182			130			705
Net income	113			87			101			58			359
2013
Operating revenues	$	724		$	700		$	755		$	747		$	2,926
Operating income	181			168			203			181			733
Net income	90			82			104			82			358
The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
(in millions)	First			Second			Third			Fourth			Total
	Quarter			Quarter			Quarter			Quarter
2014
Costs to achieve Progress Energy merger (see Note 2)	$	(2	)	$	(5	)	$	(3	)	$	(2	)	$	(12	)
2013
Costs to achieve Progress Energy merger (see Note 2)	$	(4	)	$	(5	)	$	(5	)	$	(5	)	$	(19	)

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2014
Policy Text Block [Line Items]
Nature of Operations and Basis of Consolidation	Nature of Operations and Basis of Consolidation
	Duke Energy Corporation (collectively with its subsidiaries, Duke Energy) is an energy company headquartered in Charlotte, North Carolina, subject to regulation by the Federal Energy Regulatory Commission (FERC). Duke Energy operates in the United States (U.S.) and Latin America primarily through its direct and indirect subsidiaries. Duke Energy’s subsidiaries include its subsidiary registrants, Duke Energy Carolinas, LLC (Duke Energy Carolinas); Progress Energy, Inc. (Progress Energy); Duke Energy Progress, Inc. (Duke Energy Progress); Duke Energy Florida, Inc. (Duke Energy Florida); Duke Energy Ohio, Inc. (Duke Energy Ohio) and Duke Energy Indiana, Inc. (Duke Energy Indiana). When discussing Duke Energy’s consolidated financial information, it necessarily includes the results of its six separate subsidiary registrants (collectively referred to as the Subsidiary Registrants), which, along with Duke Energy, are collectively referred to as the Duke Energy Registrants (Duke Energy Registrants).
	On July 2, 2012, Duke Energy merged with Progress Energy, with Duke Energy continuing as the surviving corporation. Progress Energy became a subsidiary of Duke Energy and Progress Energy’s regulated utility subsidiaries, Duke Energy Progress (formerly Carolina Power & Light Company d/b/a Progress Energy Carolinas, Inc.) and Duke Energy Florida (formerly Florida Power Corporation d/b/a Progress Energy Florida, Inc.), became indirect subsidiaries of Duke Energy. Duke Energy’s consolidated financial statements include Progress Energy, Duke Energy Progress and Duke Energy Florida activity beginning July 2, 2012. The impacts of acquisition accounting from Progress Energy’s merger with Duke Energy were recorded by Duke Energy and were not reflected on the financial statements of Progress Energy, Duke Energy Progress and Duke Energy Florida. See Note 2 for additional information regarding the merger. On July 2, 2012, just prior to the close of the merger, Duke Energy executed a one-for-three reverse stock split with respect to the issued and outstanding shares of Duke Energy common stock. All per-share amounts included in this Form 10-K are presented as if the stock split had been effective from the beginning of the earliest period presented.
	On August 21, 2014, Duke Energy Commercial Enterprises, Inc., an indirect wholly owned subsidiary of Duke Energy Corporation, and Duke Energy SAM, LLC, a wholly owned subsidiary of Duke Energy Ohio, entered into a purchase and sale agreement (PSA) with a subsidiary of Dynegy Inc. (Dynegy) whereby Dynegy will acquire Duke Energy Ohio’s nonregulated Midwest generation business and Duke Energy Retail Sales LLC (Disposal Group). The results of operations of the nonregulated Midwest generation business have been classified as Discontinued Operations on the Consolidated Statements of Operations for the current and prior periods presented. Duke Energy has elected to present cash flows of discontinued operations combined with cash flows of continuing operations. Unless otherwise noted, the notes to these consolidated financial statements exclude amounts related to discontinued operations for all periods presented, assets held for sale and liabilities associated with assets held for sale as of December 31, 2014. See Note 2 for additional information.
	The information in these combined notes relate to each of the Duke Energy Registrants as noted in the Index to the Combined Notes to Consolidated Financial Statements. However, none of the registrants makes any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself.
	These Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries where the respective Duke Energy Registrants have control. These Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities.
	Duke Energy Carolinas is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Carolinas is subject to the regulatory provisions of the North Carolina Utilities Commission (NCUC), Public Service Commission of South Carolina (PSCSC), U.S. Nuclear Regulatory Commission (NRC) and FERC. Substantially all of Duke Energy Carolinas’ operations qualify for regulatory accounting.
	Progress Energy is a public utility holding company headquartered in Raleigh, North Carolina, subject to regulation by the FERC. Progress Energy conducts operations through its wholly owned subsidiaries, Duke Energy Progress and Duke Energy Florida. Substantially all of Progress Energy’s operations qualify for regulatory accounting.
	Duke Energy Progress is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Progress is subject to the regulatory provisions of the NCUC, PSCSC, NRC and FERC. Substantially all of Duke Energy Progress’ operations qualify for regulatory accounting.
	Duke Energy Florida is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Florida. Duke Energy Florida is subject to the regulatory provisions of the Florida Public Service Commission (FPSC), NRC and FERC. Substantially all of Duke Energy Florida’s operations qualify for regulatory accounting.
	Duke Energy Ohio is a regulated public utility primarily engaged in the transmission and distribution of electricity in Ohio and Kentucky, in the generation business in Kentucky, and the transportation and sale of natural gas in portions of Ohio and Kentucky. Operations in Kentucky are conducted through its wholly owned subsidiary, Duke Energy Kentucky, Inc. (Duke Energy Kentucky). Duke Energy Ohio conducts competitive auctions for retail electricity supply in Ohio whereby the energy price is recovered from retail customers. References herein to Duke Energy Ohio include Duke Energy Ohio and its subsidiaries, unless otherwise noted. Duke Energy Ohio is subject to the regulatory provisions of the Public Utilities Commission of Ohio (PUCO), Kentucky Public Service Commission (KPSC) and FERC. Duke Energy Ohio applies regulatory accounting to a portion of its operations. Duke Energy has agreed to sell Duke Energy Ohio's nonregulated Midwest generation business, which sells power into wholesale energy markets, to Dynegy. See Note 2 for additional information.
	Duke Energy Indiana is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Indiana. Duke Energy Indiana is subject to the regulatory provisions of the Indiana Utility Regulatory Commission (IURC) and FERC. Substantially all of Duke Energy Indiana’s operations qualify for regulatory accounting.
	Certain prior year amounts have been reclassified to conform to the current year presentation.
Use of Estimates	Use of Estimates
	In preparing financial statements that conform to generally accepted accounting principles (GAAP) in the U.S., the Duke Energy Registrants must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses, and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.
Regulatory Accounting	Regulatory Accounting
	The majority of the Duke Energy Registrants’ operations are subject to price regulation for the sale of electricity and gas by state utility commissions or FERC. When prices are set on the basis of specific costs of the regulated operations and an effective franchise is in place such that sufficient gas or electric services can be sold to recover those costs, the Duke Energy Registrants apply regulatory accounting. Regulatory accounting changes the timing of the recognition of costs or revenues relative to a company that does not apply regulatory accounting. As a result, Regulatory assets and Regulatory liabilities are recognized on the Consolidated Balance Sheets. Regulatory assets and liabilities are amortized consistent with the treatment of the related cost in the ratemaking process. See Note 4 for further information.
Regulated Fuel Costs and Purchased Power	Regulated Fuel Costs and Purchased Power
	The Duke Energy Registrants utilize cost-tracking mechanisms, commonly referred to as fuel adjustment clauses. These clauses allow for the recovery of fuel and fuel-related costs and portions of purchased power costs through surcharges on customer rates. The difference between the costs incurred and the surcharge revenues is recorded as an adjustment to Fuel Operating Revenues – Regulated electric on the Consolidated Statements of Operations with an off-setting impact on regulatory assets or liabilities.
Cash and Cash Equivalents	Cash and Cash Equivalents
	All highly liquid investments with maturities of three months or less at the date of acquisition are considered cash equivalents. At December 31, 2014, $1,680 million of Duke Energy’s total cash and cash equivalents is held by entities domiciled in foreign jurisdictions. During the fourth quarter of 2014, Duke Energy declared a taxable dividend of historical foreign earnings in the form of notes payable that will result in the repatriation of approximately $2.7 billion in cash held and expected to be generated by International Energy over a period of up to 8 years. See Note 22 to the Consolidated Financial Statements, “Income Taxes,” for additional information.
Restricted Cash	Restricted Cash
	The Duke Energy Registrants have restricted cash related primarily to collateral assets, escrow deposits and variable interest entities (VIEs). Restricted cash balances are reflected in Other within Current Assets and in Other within Investments and Other Assets on the Consolidated Balance Sheets. At December 31, 2014 and 2013, Duke Energy had restricted cash totaling $298 million and $307 million, respectively.
Inventory	Inventory
	Inventory is used for operations and is recorded primarily using the average cost method. Inventory related to regulated operations is valued at historical cost. Inventory related to nonregulated operations is valued at the lower of cost or market. Materials and supplies are recorded as inventory when purchased and subsequently charged to expense or capitalized to property, plant and equipment when installed. Reserves are established for excess and obsolete inventory. The components of inventory are presented in the tables below.
Investments in Debt and Equity Securities	Investments in Debt and Equity Securities
	The Duke Energy Registrants classify investments into two categories — trading and available-for-sale. Both categories are recorded at fair value on the Consolidated Balance Sheets. Realized and unrealized gains and losses on trading securities are included in earnings. For certain investments of regulated operations such as the Nuclear Decommissioning Trust Fund (NDTF), realized and unrealized gains and losses (including any other-than-temporary impairments) on available-for-sale securities are recorded as a regulatory asset or liability. Otherwise, unrealized gains and losses are included in Accumulated Other Comprehensive Income (AOCI), unless other-than-temporarily impaired. Other-than-temporary impairments for equity securities and the credit loss portion of debt securities of nonregulated operations are included in earnings. Investments in debt and equity securities are classified as either current or noncurrent based on management’s intent and ability to sell these securities, taking into consideration current market liquidity. See Note 15 for further information.
Goodwill and Intangible Assets	Goodwill and Intangible Assets
	Goodwill
	Duke Energy, Progress Energy and Duke Energy Ohio perform annual goodwill impairment tests as of August 31 each year at the reporting unit level, which is determined to be an operating segment or one level below. Duke Energy, Progress Energy and Duke Energy Ohio update these tests between annual tests if events or circumstances occur that would more likely than not reduce the fair value of a reporting unit below its carrying value.
	In 2012, Progress Energy changed its goodwill impairment testing date from October 31 to August 31 to better align its annual goodwill impairment testing procedure with those of Duke Energy. The change had no impact on goodwill. Neither the change in the goodwill impairment testing date nor the merger resulted in any changes to the Progress Energy reporting units.
	Intangible Assets
	Intangible assets are included in Other in Investments and Other Assets on the Consolidated Balance Sheets. Generally, intangible assets are amortized using an amortization method that reflects the pattern in which the economic benefits of the intangible asset are consumed, or on a straight-line basis if that pattern is not readily determinable. Amortization of intangibles is reflected in Depreciation and amortization in the Consolidated Statements of Operations. Intangible assets are subject to impairment testing and if impaired, the carrying value is accordingly reduced.
	Emission allowances permit the holder of the allowance to emit certain gaseous byproducts of fossil fuel combustion, including sulfur dioxide (SO2) and nitrogen oxide (NOX). Allowances are issued by the U.S. Environmental Protection Agency (EPA) at zero cost and may also be bought and sold via third-party transactions. Allowances allocated to or acquired by the Duke Energy Registrants are held primarily for consumption. Carrying amounts for emission allowances are based on the cost to acquire the allowances or, in the case of a business combination, on the fair value assigned in the allocation of the purchase price of the acquired business.
	Renewable energy certificates are used to measure compliance with renewable energy standards and are held primarily for consumption. See Note 11 for further information.
Long-Lived Asset Impairments	Long-Lived Asset Impairments
	The Duke Energy Registrants evaluate long-lived assets, excluding goodwill, for impairment when circumstances indicate the carrying value of those assets may not be recoverable. An impairment exists when a long-lived asset’s carrying value exceeds the estimated undiscounted cash flows expected to result from the use and eventual disposition of the asset. The estimated cash flows may be based on alternative expected outcomes that are probability weighted. If the carrying value of the long-lived asset is not recoverable based on these estimated future undiscounted cash flows, the carrying value of the asset is written-down to its then-current estimated fair value and an impairment charge is recognized.
	The Duke Energy Registrants assess fair value of long-lived assets using various methods, including recent comparable third-party sales, internally developed discounted cash flow analysis and analysis from outside advisors. Significant changes in commodity prices, the condition of an asset or management’s interest in selling the asset are generally viewed as triggering events to re-assess cash flows. See Note 11 for further information.
Property, Plant and Equipment	Property, Plant and Equipment
	Property, plant and equipment are stated at the lower of depreciated historical cost net of any disallowances or fair value, if impaired. The Duke Energy Registrants capitalize all construction-related direct labor and material costs, as well as indirect construction costs such as general engineering, taxes and financing costs. See “Allowance for Funds Used During Construction (AFUDC) and Interest Capitalized” for information on capitalized financing costs. Costs of renewals and betterments that extend the useful life of property, plant and equipment are also capitalized. The cost of repairs, replacements and major maintenance projects, which do not extend the useful life or increase the expected output of the asset, are expensed as incurred. Depreciation is generally computed over the estimated useful life of the asset using the composite straight-line method. Depreciation studies are conducted periodically to update composite rates and are approved by state utility commissions and/or the FERC when required. The composite weighted-average depreciation rates, excluding nuclear fuel, are included in the table that follows.
	In general, when the Duke Energy Registrants retire regulated property, plant and equipment, original cost plus the cost of retirement, less salvage value, is charged to accumulated depreciation. However, when it becomes probable a regulated asset will be retired substantially in advance of its original expected useful life or is abandoned, the cost of the asset and the corresponding accumulated depreciation is recognized as a separate asset. If the asset is still in operation, the net amount is classified as Generation facilities to be retired, net on the Consolidated Balance Sheets. If the asset is no longer operating, the net amount is classified in Regulatory Assets on the Consolidated Balance Sheets. The carrying value of the asset is based on historical cost if the Duke Energy Registrants are allowed to recover the remaining net book value and a return equal to at least the incremental borrowing rate. If not, an impairment is recognized to the extent the net book value of the asset exceeds the present value of future revenues discounted at the incremental borrowing rate.
	When the Duke Energy Registrants sell entire regulated operating units, or retire or sell nonregulated properties, the original cost and accumulated depreciation and amortization balances are removed from Property, Plant and Equipment on the Consolidated Balance Sheets. Any gain or loss is recorded in earnings, unless otherwise required by the applicable regulatory body.
	See Note 10 for further information.
Nuclear Fuel	Nuclear Fuel
	Nuclear fuel is classified as Property, Plant and Equipment on the Consolidated Balance Sheets, except for Duke Energy Florida. Duke Energy Florida has reclassified all Crystal River Unit 3 Nuclear Station (Crystal River Unit 3) investments, including nuclear fuel, to a regulatory asset. Refer to Note 4, “Regulatory Matters,” for additional information on Crystal River Unit 3.
	Nuclear fuel in the front-end fuel processing phase is considered work in progress and not amortized until placed in service. Amortization of nuclear fuel is included within Fuel used in electric generation and purchased power - regulated in the Consolidated Statements of Operations. Amortization is recorded using the units-of-production method.
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalized	Allowance for Funds Used During Construction and Interest Capitalized
	For regulated operations, the debt and equity costs of financing the construction of property, plant and equipment are reflected as AFUDC and capitalized as a component of the cost of property, plant and equipment. AFUDC equity is reported on the Consolidated Statements of Operations as non-cash income in Other income and expenses, net. AFUDC debt is reported as a non-cash offset to Interest Expense. After construction is completed, the Duke Energy Registrants are permitted to recover these costs through their inclusion in rate base and the corresponding subsequent depreciation or amortization of those regulated assets.
	AFUDC equity, a permanent difference for income taxes, reduces the effective tax rate when capitalized and increases the effective tax rate when depreciated or amortized. See Note 22 for additional information.
	For nonregulated operations, interest is capitalized during the construction phase with an offsetting non-cash credit to Interest Expense on the Consolidated Statements of Operations.
Asset Retirement Obligations	Asset Retirement Obligations
	Asset retirement obligations are recognized for legal obligations associated with the retirement of property, plant and equipment. Substantially all asset retirement obligations are related to regulated operations. When recording an asset retirement obligation, the present value of the projected liability is recognized in the period in which it is incurred, if a reasonable estimate of fair value can be made. The liability is accreted over time. For operating plants, the present value of the liability is added to the cost of the associated asset and depreciated over the remaining life of the asset. For retired plants, the present value of the liability is recorded as a regulatory asset and expensed over the recovery period in rates.
	The present value of the initial obligation and subsequent updates are based on discounted cash flows, which include estimates regarding timing of future cash flows, selection of discount rates and cost escalation rates, among other factors. These estimates are subject to change. Depreciation expense is adjusted prospectively for any changes to the carrying amount of the associated asset. The Duke Energy Registrants receive amounts to fund the cost of the asset retirement obligation for regulated operations through a combination of regulated revenues and NDTF. As a result, the net of amounts recovered in regulated revenues, earnings on the NDTF, accretion expense and depreciation of the associated asset is deferred as a regulatory asset or liability.
	Obligations for nuclear decommissioning are based on site-specific cost studies. Duke Energy Carolinas and Duke Energy Progress assume prompt dismantlement of the nuclear facilities after operations are ceased. Duke Energy Florida assumes Crystal River Unit 3 will be placed into a safe storage configuration until eventual dismantlement begins in approximately 60 years. Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida also assume that spent fuel will be stored on site until such time that it can be transferred to a U.S. Department of Energy (DOE) facility.
	Obligations for closure of ash basins are based upon discounted cash flows of estimated costs based upon probability weightings of the potential closure methods as evaluated on a site by site basis. Duke Energy Registrants with ash basins in North Carolina and certain basins in South Carolina and Indiana have a legal obligation that results in recognition of an asset retirement obligation at December 31, 2014. See Notes 5 and 9 for further information
Revenue Recognition and Unbilled Revenue	Revenue Recognition and Unbilled Revenue
	Revenues on sales of electricity and gas are recognized when service is provided or the product is delivered. Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes and meter reading schedules.
	Unbilled revenues are included within Receivables and Restricted receivables of variable interest entities on the Consolidated Balance Sheets
Derivatives and Hedging	Derivatives and Hedging
	Derivative and non-derivative instruments may be used in connection with commodity price, interest rate and foreign currency risk management activities, including swaps, futures, forwards and options. All derivative instruments except those that qualify for the normal purchase/normal sale (NPNS) exception are recorded on the Consolidated Balance Sheets at their fair value. Qualifying derivative instruments may be designated as either cash flow hedges or fair value hedges. Other derivative instruments (undesignated contracts) either have not been designated or do not qualify as hedges. The effective portion of the change in the fair value of cash flow hedges is recorded in AOCI. The effective portion of the change in the fair value of a fair value hedge is offset in net income by changes in the hedged item. For activity subject to regulatory accounting, gains and losses on derivative contracts are reflected as regulatory assets or liabilities and not as other comprehensive income or current period income. As a result, changes in fair value of these derivatives have no immediate earnings impact.
	Formal documentation, including transaction type and risk management strategy, is maintained for all contracts accounted for as a hedge. At inception and at least every three months thereafter, the hedge contract is assessed to see if it is highly effective in offsetting changes in cash flows or fair values of hedged items.
	See Note 14 for further information.
Captive Insurance Reserves	Captive Insurance Reserves
	Duke Energy has captive insurance subsidiaries that provide coverage, on an indemnity basis, to the Subsidiary Registrants as well as certain third parties, on a limited basis, for various business risks and losses, such as property, workers’ compensation and general liability. Liabilities include provisions for estimated losses incurred but not yet reported (IBNR), as well as estimated provisions for known claims. IBNR reserve estimates are primarily based upon historical loss experience, industry data and other actuarial assumptions. Reserve estimates are adjusted in future periods as actual losses differ from experience.
	Duke Energy, through its captive insurance entities, also has reinsurance coverage with third parties for certain losses above a per occurrence and/or aggregate retention. Receivables for reinsurance coverage are recognized when realization is deemed probable.
Unamortized Debt Premium, Discount and Expense	Unamortized Debt Premium, Discount and Expense
	Premiums, discounts and expenses incurred with the issuance of outstanding long-term debt are amortized over the term of the debt issue. Call premiums and unamortized expenses associated with refinancing higher-cost debt obligations in the regulated operations are amortized. Amortization expense is recorded as Interest Expense in the Consolidated Statements of Operations and is reflected as Depreciation, amortization and accretion within Net cash provided by operating activities on the Consolidated Statements of Cash Flows.
Loss Contingencies and Environmental Liabilities	Loss Contingencies and Environmental Liabilities
	Contingent losses are recorded when it is probable a loss has occurred and can be reasonably estimated. When a range of the probable loss exists and no amount within the range is a better estimate than any other amount, the minimum amount in the range is recorded. Unless otherwise required by GAAP, legal fees are expensed as incurred.
	Environmental liabilities are recorded on an undiscounted basis when environmental remediation or other liabilities becomes probable and can be reasonably estimated. Environmental expenditures related to past operations that do not generate current or future revenues are expensed. Environmental expenditures related to operations that generate current or future revenues are expensed or capitalized, as appropriate. Certain environmental expenditures receive regulatory accounting treatment and are recorded as regulatory assets.
	See Notes 4 and 5 for further information.
Pension and Other Post-Retirement Benefit Plans	Pension and Other Post-Retirement Benefit Plans
	Duke Energy maintains qualified, non-qualified and other post-retirement benefit plans. Eligible employees of the Subsidiary Registrants participate in the respective qualified, non-qualified and other post-retirement benefit plans and the Subsidiary Registrants are allocated their proportionate share of benefit costs. See Note 21 for further information, including significant accounting policies associated with these plans.
Severance and Special Termination Benefits	Severance and Special Termination Benefits
	Duke Energy has an ongoing severance plan under which, in general, the longer a terminated employee worked prior to termination the greater the amount of severance benefits. A liability for involuntary severance is recorded once an involuntary severance plan is committed to by management, or sooner, if involuntary severances are probable and can be reasonably estimated. For involuntary severance benefits incremental to its ongoing severance plan benefits, the fair value of the obligation is expensed at the communication date if there are no future service requirements, or over the required future service period. From time to time, Duke Energy offers special termination benefits under voluntary severance programs. Special termination benefits are recorded immediately upon employee acceptance absent a significant retention period. Otherwise, the cost is recorded over the remaining service period. Employee acceptance of voluntary severance benefits is determined by management based on the facts and circumstances of the benefits being offered. See Note 19 for further information.
Guarantees	Guarantees
	Liabilities are recognized at the time of issuance or material modification of a guarantee for the estimated fair value of the obligation it assumes. Fair value is estimated using a probability-weighted approach. The obligation is reduced over the term of the guarantee or related contract in a systematic and rational method as risk is reduced. Any additional contingent loss for guarantee contracts subsequent to the initial recognition of a liability is accounted for and recognized at the time a loss is probable and can be reasonably estimated. See Note 7 for further information.
Stock-Based Compensation	Stock-Based Compensation
	Stock-based compensation represents costs related to stock-based awards granted to employees and Duke Energy Board of Directors (Board of Directors) members. Duke Energy recognizes stock-based compensation based upon the estimated fair value of awards, net of estimated forfeitures at the date of issuance. The recognition period for these costs begin at either the applicable service inception date or grant date and continues throughout the requisite service period, or for certain share-based awards until the employee becomes retirement eligible, if earlier. Compensation cost is recognized as expense or capitalized as a component of property, plant and equipment. See Note 20 for further information.
Income Taxes	Income Taxes
	Duke Energy and its subsidiaries file a consolidated federal income tax return and other state and foreign jurisdictional returns. The Subsidiary Registrants entered into a tax-sharing agreement with Duke Energy. Income taxes recorded represent amounts the Subsidiary Registrants would incur as separate C-Corporations. Deferred income taxes have been provided for temporary differences between GAAP and tax bases of assets and liabilities because the differences create taxable or tax-deductible amounts for future periods. Deferred taxes are not provided on translation gains and losses when earnings of a foreign operation are expected to be indefinitely reinvested. Investment tax credits (ITC) associated with regulated operations are deferred and amortized as a reduction of income tax expense over the estimated useful lives of the related properties.
	Positions taken or expected to be taken on tax returns, including the decision to exclude certain income or transactions from a return, are recognized in the financial statements when it is more likely than not the tax position can be sustained based solely on the technical merits of the position. The largest amount of tax benefit that is greater than 50 percent likely of being effectively settled is recorded. Management considers a tax position effectively settled when: (i) the taxing authority has completed its examination procedures, including all appeals and administrative reviews; (ii) the Duke Energy Registrants do not intend to appeal or litigate the tax position included in the completed examination; and (iii) it is remote the taxing authority would examine or re-examine the tax position. The amount of a tax return position that is not recognized in the financial statements is disclosed as an unrecognized tax benefit. If these unrecognized tax benefits are later recognized, then there will be a decrease in income taxes payable, an income tax refund or a swap between deferred and current taxes payable. If the portion of tax benefits that has been recognized changes and those tax benefits are subsequently unrecognized, then the previously recognized tax benefits may impact the financial statements through increasing income taxes payable, reducing income tax refunds receivable changing deferred taxes. Changes in assumptions on tax benefits may also impact interest expense or interest income and may result in the recognition of tax penalties.
	Tax-related interest and penalties are recorded in Interest Expense and Other Income and Expenses, net, in the Consolidated Statements of Operations.
	See Note 22 for further information.
Accounting for Renewable Energy Tax Credits and Cash Grants	Accounting for Renewable Energy Tax Credits and Cash Grants
	When Duke Energy receives ITC or cash grants on wind or solar facilities, it reduces the basis of the property recorded on the Consolidated Balance Sheets by the amount of the ITC or cash grant and, therefore, the ITC or grant benefit is recognized through reduced depreciation expense. Additionally, certain tax credits and government grants received provide for initial tax depreciable base in excess of the book carrying value equal to one half of the ITC or government grant. Deferred tax benefits are recorded as a reduction to income tax expense in the period that the basis difference is created.
Excise Taxes	Excise Taxes
	Certain excise taxes levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis. Otherwise, the taxes are accounted for net. Excise taxes accounted for on a gross basis as both operating revenues and property and other taxes in the Consolidated Statements of Operations were as follows.
Foreign Currency Transaction	Foreign Currency Translation
	The local currencies of most of Duke Energy’s foreign operations have been determined to be their functional currencies. However, certain foreign operations’ functional currency has been determined to be the U.S. dollar, based on an assessment of the economic circumstances of the foreign operation. Assets and liabilities of foreign operations whose functional currency is not the U.S. dollar are translated into U.S. dollars at the exchange rates in effect at period end. Translation adjustments resulting from changes in exchange rates are included in AOCI. Revenue and expense accounts are translated at average exchange rates during the year. Remeasurement gains and losses arising from balances and transactions denominated in currencies other than the local currency are included in the results of operations when they occur.
Dividend Restrictions and Unappropriated Retained Earnings	Dividend Restrictions and Unappropriated Retained Earnings
	Duke Energy does not have any legal, regulatory or other restrictions on paying common stock dividends to shareholders. However, as further described in Note 4, due to conditions established by regulators in conjunction with merger transaction approvals, Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana have restrictions on paying dividends or otherwise advancing funds to Duke Energy. At December 31, 2014 and 2013, an insignificant amount of Duke Energy’s consolidated Retained earnings balance represents undistributed earnings of equity method investments.
New Accounting Standards	New Accounting Standards
	The new accounting standards that were adopted for 2014, 2013 and 2012 had no significant impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. Disclosures have been enhanced to provide a discussion and tables on derivative contracts subject to enforceable master netting agreements and a table of quantitative disclosures about unobservable inputs. See Notes 14 and 16 for further information.
	The following new Accounting Standards Updates (ASUs) have been issued, but have not yet been adopted by the Duke Energy Registrants, as of December 31, 2014.
	ASC 205 — Reporting Discontinued Operations. In April 2014, the Financial Accounting Standards Board (FASB) issued revised accounting guidance for reporting discontinued operations. A discontinued operation would be either (i) a component of an entity or a group of components of an entity that represents a separate major line of business or major geographical area of operations that either has been disposed of or is part of a single coordinated plan to be classified as held for sale or (ii) a business that, on acquisition, meets the criteria to be classified as held for sale.
	For the Duke Energy Registrants, this guidance is effective on a prospective basis for interim and annual periods beginning January 1, 2015. This guidance will also result in increased disclosures for discontinued operations or disposals of individually significant components that are not classified as discontinued operations. In general, this guidance is likely to result in fewer disposals of assets qualifying as discontinued operations.
	ASC 606 — Revenue from Contracts with Customers. In May 2014, the FASB issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendments in this update also require disclosure of sufficient information to allow users to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers.
	For the Duke Energy Registrants, this guidance is effective for interim and annual periods beginning January 1, 2017. Duke Energy is currently evaluating the requirements. The ultimate impact of the new standard has not yet been determined.
Duke Energy Ohio [Member]
Policy Text Block [Line Items]
Revenue Recognition and Unbilled Revenue	Additionally, Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, Cinergy Receivables Company, LLC (CRC) and account for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 17 for further information.
Duke Energy Indiana [Member]
Policy Text Block [Line Items]
Revenue Recognition and Unbilled Revenue	Additionally, Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, Cinergy Receivables Company, LLC (CRC) and account for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 17 for further information.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Organization And Basis Of Presentation [Line Items]
Schedule of Current and Noncurrent Assets and Liabilities	Other within Current Assets includes the current portion of deferred tax assets, which are disclosed in Note 22. Additionally, the following are included in Other within Current Assets or Current Liabilities in the Consolidated Balance Sheets of the Duke Energy Registrants at December 31, 2014 and 2013. The amounts presented exceeded 5 percent of current assets or 5 percent of current liabilities unless otherwise noted.
				December 31,
	(in millions)	Location		2014				2013
	Duke Energy
	Accrued compensation	Current Liabilities		$	638			$	621
	Duke Energy Carolinas
	Accrued compensation	Current Liabilities		$	216			$	198
	Collateral liabilities	Current Liabilities		128				120
	Progress Energy
	Income taxes receivable(b)	Current Assets		$	718			$	119
	Customer deposits	Current Liabilities		360				349
	Accrued compensation(a)	Current Liabilities		174				214
	Derivative liabilities(b)	Current Liabilities		271				—
	Duke Energy Progress
	Income taxes receivable(b)	Current Assets		$	272			$	15
	Customer deposits	Current Liabilities		135				129
	Accrued compensation	Current Liabilities		116				121
	Derivative liabilities(b)	Current Liabilities		108				38
	Duke Energy Florida
	Income taxes receivable(b)	Current Assets		$	177			$	65
	Customer deposits	Current Liabilities		225				220
	Accrued compensation(a)	Current Liabilities		57				65
	Derivative liabilities(b)	Current Liabilities		163				—
	Duke Energy Ohio
	Collateral assets(a)	Current Assets		$	13			$	122
	Duke Energy Indiana
	Income taxes receivable	Current Assets		$	98			$	56
	Accrued compensation(a)	Current Liabilities		25				25
	Collateral liabilities	Current Liabilities		43				40
	(a) Does not exceed 5 percent of total current assets or liabilities, as appropriate, on the Consolidated Balance Sheets at December 31, 2014.
	(b) Does not exceed 5 percent of total current assets or liabilities, as appropriate, on the Consolidated Balance Sheets at December 31, 2013.
Schedule of Net Income Amounts Attributable to Controlling Interests	The following table presents Net Income Attributable to Duke Energy Corporation for continuing operations and discontinued operations.
		Years ended December 31,
		2014							2013							2012
	(in millions)	Duke Energy			Progress Energy				Duke Energy			Progress Energy				Duke Energy			Progress Energy
	Income from Continuing Operations	$	2,465		$	880			$	2,590		$	659			1,611			355
	Income of Continuing Operations Attributable to Noncontrolling Interests	14			5				16			3				18			7
	Income from Continuing Operations Attributable to Duke Energy Corporation	$	2,451		$	875			$	2,574		$	656			$	1,593		$	348
	(Loss) Income From Discontinued Operations, net of tax	$	(576	)	$	(6	)		$	86		$	16			171			52
	Loss of Discontinued Operations attributable to Noncontrolling Interests, net of tax	(8		)	—				(5		)	—				(4		)	—
	(Loss) Income From Discontinued Operations Attributable to Duke Energy Corporation, net of tax	$	(568	)	$	(6	)		$	91		$	16			$	175		$	52
	Net Income	$	1,889		$	874			$	2,676		$	675			$	1,782		$	407
	Net Income Attributable to Noncontrolling Interest	6			5				11			3				14			7
	Net Income Attributable to Duke Energy Corporation	$	1,883		$	869			$	2,665		$	672			$	1,768		$	400
Components Of Inventory	The components of inventory are presented in the tables below.
		December 31, 2014
	(in millions)	Duke				Duke				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke				Duke
		Energy				Energy Carolinas																Energy				Energy
																						Ohio				Indiana
	Materials and supplies	$	2,102			$	719			$	981			$	676			$	305			$	67			$	258
	Coal held for electric generation	997				362				329				150				178				21				275
	Oil, gas and other fuel held for electric generation	360				43				280				140				140				9				4
	Total inventory	$	3,459			$	1,124			$	1,590			$	966			$	623			$	97			$	537
		December 31, 2013
	(in millions)	Duke				Duke				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke				Duke
		Energy				Energy Carolinas																Energy				Energy
																						Ohio				Indiana
	Materials and supplies	$	1,901			$	654			$	854			$	567			$	287			$	117			$	193
	Coal held for electric generation	1,018				374				334				187				147				65				238
	Oil, gas and other fuel held for electric generation	331				37				236				99				137				47				3
	Total inventory	$	3,250			$	1,065			$	1,424			$	853			$	571			$	229			$	434
Schedule Of Property, Plant And Equipment	The composite weighted-average depreciation rates, excluding nuclear fuel, are included in the table that follows.
		Years Ended December 31,
		2014			2013			2012
	Duke Energy	2.8	%		2.8	%		2.9	%
	Duke Energy Carolinas	2.7	%		2.8	%		2.8	%
	Progress Energy	2.5	%		2.5	%		2.6	%
	Duke Energy Progress	2.5	%		2.5	%		2.7	%
	Duke Energy Florida	2.7	%		2.4	%		2.5	%
	Duke Energy Ohio	2.3	%		3.3	%		3.2	%
	Duke Energy Indiana	3	%		2.8	%		3.3	%
	The following tables summarize the property, plant and equipment.
		31-Dec-14
	(in millions)	Estimated Useful Life (Years)		Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio				Duke Energy Indiana
	Land			$	1,459			$	403			$	704			$	380			$	324			$	114			$	108
	Plant - Regulated
	Electric generation, distribution and transmission	2 - 138		82,206				31,751				33,672				20,616				13,056				3,956				11,911
	Natural gas transmission and distribution	Dec-67		2,230				—				—				—				—				2,230				—
	Other buildings and improvements	9 - 100		1,445				465				607				286				318				200				173
	Plant - Nonregulated
	Electric generation, distribution and transmission	30-Jan		2,380				—				—				—				—				—				—
	Other buildings and improvements	May-50		2,498				—				—				—				—				—				—
	Nuclear fuel			2,865				1,676				1,190				1,190				—				—				—
	Equipment	Mar-34		1,762				341				506				388				118				330				166
	Construction in process			4,519				2,081				1,215				908				307				97				481
	Other	May-80		3,497				655				756				439				310				214				195
	Total property, plant and equipment(a)(d)			104,861				37,372				38,650				24,207				14,433				7,141				13,034
	Total accumulated depreciation - regulated(b)(c)(d)			(32,628		)		(12,700		)		(13,506		)		(9,021		)		(4,478		)		(2,213		)		(4,219		)
	Total accumulated depreciation - nonregulated(c)(d)			(2,196		)		—				—				—				—				—				—
	Generation facilities to be retired, net			9				—				—				—				—				9				—
	Total net property, plant and equipment			$	70,046			$	24,672			$	25,144			$	15,186			$	9,955			$	4,937			$	8,815
	(a)	Includes capitalized leases of $1,548 million, $40 million, $315 million, $146 million, $169 million, $98 million, and $30 million at Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, and Duke Energy Indiana, respectively, primarily in regulated plant. The Progress Energy, Duke Energy Progress and Duke Energy Florida amounts are net of $72 million, $5 million and $67 million, respectively, of accumulated amortization of capitalized leases.
	(b)	Includes $1,408 million, $847 million, $561 million and $561 million of accumulated amortization of nuclear fuel at Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Progress, respectively.
	(c)	Includes accumulated amortization of capitalized leases of $52 million, $8 million, $25 million and $6 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana, respectively.
	(d)	Includes gross property, plant and equipment cost of consolidated VIEs of $1,873 million and accumulated depreciation of consolidated VIEs of $257 million at Duke Energy.
		31-Dec-13
	(in millions)	Estimated Useful Life (Years)		Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio				Duke Energy Indiana
	Land			$	1,481			$	397			$	705			$	383			$	321			$	137			$	105
	Plant - Regulated
	Electric generation, distribution and transmission	2 - 125		78,272				30,018				31,792				19,190				12,601				3,925				11,594
	Natural gas transmission and distribution	Dec-67		2,138				—				—				—				—				2,138				—
	Other buildings and improvements	2 - 100		1,397				447				610				282				315				190				159
	Plant - Nonregulated
	Electric generation, distribution and transmission	2 - 100		6,267				—				—				—				—				4,017				—
	Other buildings and improvements	9 -100		2,512				—				—				—				—				5				—
	Nuclear fuel			2,458				1,446				1,012				1,012				—				—				—
	Equipment	Jan-33		1,557				287				621				357				94				317				146
	Construction in process			3,595				1,741				873				631				238				166				307
	Other	May-33		3,438				570				867				418				294				248				178
	Total property, plant and equipment(a)(d)			103,115				34,906				36,480				22,273				13,863				11,143				12,489
	Total accumulated depreciation - regulated(b)(c)(d)			(31,659		)		(11,894		)		(13,098		)		(8,623		)		(4,252		)		(2,160		)		(3,913		)
	Total accumulated depreciation - nonregulated(c)(d)			(1,966		)		—				—				—				—				(748		)		—
	Total net property, plant and equipment			$	69,490			$	23,012			$	23,382			$	13,650			$	9,611			$	8,235			$	8,576
	(a)	Includes capitalized leases of $1,606 million, $53 million, $328 million, $148 million, $180 million, $96 million, and $30 million at Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, and Duke Energy Indiana, respectively, primarily in regulated plant. The Progress Energy, Duke Energy Progress and Duke Energy Florida amounts are net of $60 million, an insignificant amount and $57 million, respectively, of accumulated amortization of capitalized leases.
	(b)	Includes $1,118 million, $681 million, $438 million and $438 million of accumulated amortization of nuclear fuel at Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Progress, respectively.
	(c)	Includes accumulated amortization of capitalized leases of $40 million, $4 million, $21 million and $5 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana, respectively.
	(d)	Includes gross property, plant and equipment cost of consolidated VIEs of $1,678 million and accumulated depreciation of consolidated VIEs of $175 million at Duke Energy.
Schedule of Allowance for Doubtful Accounts	Allowances for doubtful accounts are presented in the following table.
		December 31,
	(in millions)	2014				2013			2012
	Allowance for Doubtful Accounts
	Duke Energy	$	17			30			34
	Duke Energy Carolinas	3				3			3
	Progress Energy	8				14			16
	Duke Energy Progress	7				10			9
	Duke Energy Florida	2				4			7
	Duke Energy Ohio	2				2			2
	Duke Energy Indiana	1				1			1
	Allowance for Doubtful Accounts - VIEs
	Duke Energy	$	51			43			44
	Duke Energy Carolinas	6				6			6
	Progress Energy	8				—			—
	Duke Energy Progress	5				—			—
	Duke Energy Florida	3				—			—
Schedule of Excise Taxes	Excise taxes accounted for on a gross basis as both operating revenues and property and other taxes in the Consolidated Statements of Operations were as follows.
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Duke Energy	$	498			$	602			$	466
	Duke Energy Carolinas	94				164				161
	Progress Energy	263				304				317
	Duke Energy Progress	56				115				113
	Duke Energy Florida	207				189				205
	Duke Energy Ohio	103				105				102
	Duke Energy Indiana	38				29				33
Unbilled Revenues [Member]
Organization And Basis Of Presentation [Line Items]
Schedule Of Unbilled Revenues With Restricted Receivables	Unbilled revenues are included within Receivables and Restricted receivables of variable interest entities on the Consolidated Balance Sheets as shown in the following table. This table excludes amounts included in assets held for sale (AHFS).
		December 31,
	(in millions)	2014				2013
	Duke Energy	$	827			$	937
	Duke Energy Carolinas	295				323
	Progress Energy	217				189
	Duke Energy Progress	135				120
	Duke Energy Florida	82				69
	Duke Energy Ohio	—				55
	Duke Energy Indiana	27				5
	Additionally, Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, Cinergy Receivables Company, LLC (CRC) and account for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 17 for further information. These receivables for unbilled revenues are shown in the table below.
		December 31,
	(in millions)	2014			2013
	Duke Energy Ohio	79			89
	Duke Energy Indiana	112			144

Acquisitions_Dispositions_and_1

Acquisitions, Dispositions and Sales of Other Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Significant Acquisitions and Disposals [Line Items]
Schedule of Purchase Price Calculation	Total consideration transferred was based on the closing price of Duke Energy common shares on July 2, 2012, and was calculated as shown in the following table.
	(dollars in millions, except per share amounts; shares in thousands)
	Progress Energy common shares outstanding at July 2, 2012	296,116
	Exchange ratio	0.87083
	Duke Energy common shares issued for Progress Energy common shares outstanding	257,867
	Closing price of Duke Energy common shares on July 2, 2012	$	69.84
	Purchase price for common stock	$	18,009
	Fair value of outstanding earned stock compensation awards	62
	Total purchase price	$	18,071
Schedule of Purchase Price Allocation	The completed purchase price allocation is presented in the following table.
	(in millions)
	Current assets	$	3,204
	Property, plant and equipment	23,141
	Goodwill	12,469
	Other long-term assets	9,990
	Total assets	48,804
	Current liabilities, including current maturities of long-term debt	3,593
	Long-term liabilities, preferred stock and noncontrolling interests	10,394
	Long-term debt	16,746
	Total liabilities and preferred stock	30,733
	Total purchase price	$	18,071
Pro Forma Information	The following unaudited pro forma financial information reflects the consolidated results of operations of Duke Energy and the amortization of purchase price adjustments assuming the merger had taken place on January 1, 2012. The unaudited pro forma financial information has been presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved or future consolidated results of operations of Duke Energy.
	Non-recurring merger consummation, integration and other costs incurred by Duke Energy and Progress Energy during the period have been excluded from pro forma earnings presented below. After-tax non-recurring merger consummation, integration and other costs incurred by both Duke Energy and Progress Energy were $413 million for the year ended 2012. The pro forma financial information also excludes potential future cost savings or non-recurring charges related to the merger.
		Year Ended December 31,
	(in millions, except per share amounts)	2012
	Revenues	$	23,976
	Net Income Attributable to Duke Energy Corporation	2,417
	Basic and Diluted Earnings Per Share	3.43
Accounting Charges Related to the Merger Consummation	The following pretax consummation charges were recognized upon closing of the merger and are included in the Duke Energy Registrants’ Consolidated Statements of Operations and Comprehensive Income for the year ended December 31, 2012.
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	FERC Mitigation	$	117		$	46		$	71	$	71	$	—	$	—	$	—
	Severance costs	196			63			82		55		27		21		18
	Community support, charitable	169			79			74		63		11		7		6
	contributions and other
	Total	$	482		$	188		$	227	$	189	$	38	$	28	$	24
Generation Facilities of Disposal Group	The following table presents information related to the Duke Energy Ohio generation plants included in the Disposal Group.
	Facility	Plant Type		Primary Fuel	Location		Total MW Capacity(c)		Owned MW Capacity(c)	Ownership Interest
	Stuart(a)(b)	Fossil Steam		Coal	OH		2,308		900	39	%
	Zimmer(a)	Fossil Steam		Coal	OH		1,300		605	46.5	%
	Hanging Rock	Combined Cycle		Gas	OH		1,226		1,226	100	%
	Miami Fort (Units 7 and 8)(a)	Fossil Steam		Coal	OH		1,020		652	64	%
	Conesville(a)(b)	Fossil Steam		Coal	OH		780		312	40	%
	Washington	Combined Cycle		Gas	OH		617		617	100	%
	Fayette	Combined Cycle		Gas	PA		614		614	100	%
	Killen(a)(b)	Fossil Steam		Coal	OH		600		198	33	%
	Lee	Combustion Turbine		Gas	IL		568		568	100	%
	Dick's Creek	Combustion Turbine		Gas	OH		136		136	100	%
	Miami Fort	Combustion Turbine		Oil	OH		56		56	100	%
	Total Midwest Generation						9,225		5,884
	(a)	Jointly owned with American Electric Power Generation Resources and/or The Dayton Power & Light Company.
	(b)	Station is not operated by Duke Energy Ohio
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The following table presents the results of discontinued operations.
	Duke Energy
		Years Ended December 31,
	(in millions)	2014			2013			2012
	Operating Revenues	$	1,748		$	1,885		$	1,771
	Estimated loss on disposition	(929		)	—			—
	(Loss) Income before income taxes	$	(818	)	$	141		$	227
	Income tax (benefit) expense	(294		)	56			82
	(Loss) Income from discontinued operations of the Disposal Group	(524		)	85			145
	Other, net of tax(a)	(52		)	1			26
	(Loss) Income from Discontinued Operations, net of tax	$	(576	)	$	86		$	171
	(a)	Other discontinued operations relate to prior sales of businesses and includes indemnifications provided for certain legal, tax and environmental matters, and foreign currency translation adjustments.
	Duke Energy Ohio
		Years Ended December 31,
	(in millions)	2014			2013			2012
	Operating Revenues	$	1,299		$	1,503		$	1,435
	Estimated loss on disposition	(959		)	—			—
	(Loss) Income before income taxes	$	(863	)	$	67		$	195
	Income tax (benefit) expense	(300		)	32			65
	(Loss) Income from Discontinued Operations, net of tax	$	(563	)	$	35		$	130
Disclosure of Long Lived Assets Held-for-sale	The following table presents the Disposal Group's carrying values in the Consolidated Balance Sheets' major classes of Assets held for sale.
		December 31, 2014
	(in millions)	Duke Energy			Duke Energy Ohio
	Current assets	$	364		$	316
	Investments and other assets	52			46
	Property, plant and equipment	2,590			2,559
	Total assets held for sale	$	3,006		$	2,921
	Current liabilities	$	262		$	246
	Deferred credits and other liabilities	35			34
	Total liabilities associated with assets held for sale	$	297		$	280

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting Information [Line Items]
Business Segment Data	The following table summarizes the net loss for Other for each of these entities.
		Years Ended December 31,
	(in millions)	2014			2013			2012
	Duke Energy Carolinas	$	(79	)	$	(97	)	$	(169	)
	Progress Energy	(190		)	(241		)	(379		)
	Duke Energy Progress	(31		)	(46		)	(139		)
	Duke Energy Florida	(19		)	(24		)	(58		)
	Duke Energy Indiana	(11		)	(16		)	(27		)
	The remainder of Duke Energy’s operations is presented as Other. While it is not an operating segment, Other primarily includes unallocated corporate interest expense, certain unallocated corporate costs, Bison Insurance Company Limited (Bison), Duke Energy’s wholly owned, captive insurance subsidiary, and contributions to the Duke Energy Foundation. On December 31, 2013, Duke Energy sold its interest in DukeNet Communications Holdings, LLC (DukeNet) to Time Warner Cable, Inc.
		Year Ended December 31, 2014
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
	Unaffiliated Revenues	$	22,228		$	1,417		$	255		$	23,900		$	25		$	—		$	23,925
	Intersegment Revenues	43			—			—			43			80			(123		)	—
	Total Revenues	$	22,271		$	1,417		$	255		$	23,943		$	105		$	(123	)	$	23,925
	Interest Expense	$	1,093		$	93		$	58		$	1,244		$	400		$	(22	)	$	1,622
	Depreciation and amortization	2,759			97			92			2,948			118			—			3,066
	Equity in earnings of unconsolidated affiliates	(3		)	120			10			127			3			—			130
	Income tax expense (benefit)(a)	1,628			449			(171		)	1,906			(237		)	—			1,669
	Segment income(b)(c)(d)	2,795			55			(55		)	2,795			(334		)	(10		)	2,451
	Add back noncontrolling interest component																			14
	Loss from discontinued operations, net of tax																			(576		)
	Net income																			$	1,889
	Capital investments expenditures and acquisitions	$	4,744		$	67		$	555		$	5,366		$	162		$	—		$	5,528
	Segment Assets	106,657			5,132			6,278			118,067			2,453			189			120,709
	(a)	International Energy includes a tax adjustment of $373 million related to deferred tax impact resulting from the decision to repatriate all cumulative historical undistributed foreign earnings. See Note 22 for additional information.
	(b)	Commercial Power recorded a pretax impairment charge of $94 million related to OVEC. See Note 11 for additional information.
	(c)	Other includes costs to achieve the Progress Energy merger. See Notes 2 and 25 for additional information about the merger and related costs.
	(d)	Regulated Utilities includes an increase in the litigation reserve related to the criminal investigation of the Dan River coal ash spill. See Note 5 for additional information.
		Year Ended December 31, 2013
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
	Unaffiliated Revenues(a)(b)(c)	$	20,871		$	1,546		$	254		$	22,671		$	85		$	—		$	22,756
	Intersegment Revenues	39			—			6			45			90			(135		)	—
	Total Revenues	$	20,910		$	1,546		$	260		$	22,716		$	175		$	(135	)	$	22,756
	Interest Expense	$	986		$	86		$	61		$	1,133		$	416		$	(6	)	$	1,543
	Depreciation and amortization	2,323			100			110			2,533			135			—			2,668
	Equity in earnings of unconsolidated affiliates	(1		)	110			7			116			6			—			122
	Income tax expense (benefit)	1,522			166			(148		)	1,540			(335		)	—			1,205
	Segment income (a)(b)(c)(d)(e)(f)(g)	2,504			408			(88		)	2,824			(238		)	(12		)	2,574
	Add back noncontrolling interest component																			16
	Income from discontinued operations, net of tax																			86
	Net income																			$	2,676
	Capital investments expenditures and acquisitions	$	5,049		$	67		$	268		$	5,384		$	223		$	—		$	5,607
	Segment Assets	99,884			4,998			6,955			111,837			2,754			188			114,779
	(a)	In May 2013, the PUCO approved a Duke Energy Ohio settlement agreement that provides for a net annual increase in electric distribution revenues beginning in May 2013. This rate increase impacts Regulated Utilities. See Note 4 for additional information.
	(b)	In June 2013, NCUC approved a Duke Energy Progress settlement agreement that included an increase in rates in the first year beginning in June 2013. This rate increase impacts Regulated Utilities. See Note 4 for additional information.
	(c)	In September 2013, Duke Energy Carolinas implemented revised customer rates approved by the NCUC and the PSCSC. These rate increases impact Regulated Utilities. See Note 4 for additional information.
	(d)	Regulated Utilities recorded an impairment charge related to Duke Energy Florida's Crystal River Unit 3. See Note 4 for additional information.
	(e)	Regulated Utilities recorded an impairment charge related to the letter Duke Energy Progress filed with the NRC requesting the NRC to suspend its review activities associated with the combined construction and operating license (COL) at the Harris site. Regulated Utilities also recorded an impairment charge related to the write-off of the wholesale portion of the Levy investments at Duke Energy Florida in accordance with the 2013 Settlement. See Note 4 for additional information.
	(f)	Other includes costs to achieve the Progress Energy merger. See Notes 2 and 25 for additional information about the merger and related costs.
	(g)	Other includes gain from the sale of Duke Energy's ownership interest in DukeNet. See Note 12 for additional information on the sale of DukeNet.
		Year Ended December 31, 2012
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Reportable Segments			Other			Eliminations			Total
	Unaffiliated Revenues	$	16,042		$	1,549		$	299		$	17,890		$	22		$	—		$	17,912
	Intersegment Revenues	38			—			8			46			62			(108		)	—
	Total Revenues	$	16,080		$	1,549		$	307		$	17,936		$	84		$	(108	)	$	17,912
	Interest Expense	$	806		$	77		$	63		$	946		$	298		$	—		$	1,244
	Depreciation and amortization	1,827			99			85			2,011			134			—			2,145
	Equity in earnings of unconsolidated affiliates	(5		)	134			14			143			5			—			148
	Income tax expense (benefit)	942			149			(82		)	1,009			(386		)	—			623
	Segment income (a)(b)	1,744			439			(59		)	2,124			(523		)	(8		)	1,593
	Add back noncontrolling interest component																			18
	Income from discontinued operations, net of tax																			171
	Net income																			$	1,782
	Capital investments expenditures and acquisitions	$	4,220		$	551		$	1,038		$	5,809		$	149		$	—		$	5,958
Segment Assets	98,162			5,406			6,992			110,560			3,126			170			113,856
(a)	Regulated Utilities recorded charges related to Duke Energy Indiana's Integrated Gasification Combined Cycle
(IGCC) project. See Note 4 for additional information about these charges. Regulated Utilities also recorded the reversal of expenses of $60 million, net of tax, related to a prior year Voluntary Opportunity Plan in accordance with Duke Energy Carolinas' 2011 rate case. See Note 19 for additional information about these expenses.
(b)	Other includes costs to achieve the Progress Energy merger. See Notes 2 and 25 for additional information about the merger and related costs.
Schedule Of Revenue And Long-Lived Assets, By Geographical Area	Geographical Information
	(in millions)	U.S.			Latin America(a)			Consolidated
	2014
	Consolidated revenues	$	22,508		$	1,417		$	23,925
	Consolidated long-lived assets	80,709			2,458			83,167
	2013
	Consolidated revenues	$	21,211		$	1,545		$	22,756
	Consolidated long-lived assets	78,581			2,781			81,362
	2012
	Consolidated revenues	$	16,366		$	1,546		$	17,912
	Consolidated long-lived assets	79,144			2,467			81,611
	(a)	Change in amounts of long-lived assets in Latin America includes foreign currency translation adjustments on property, plant and equipment and other long-lived asset balances.
Schedule of Revenue, By Products and Services	Products and Services
	(in millions)	Retail Electric			Wholesale Electric			Retail Natural Gas			Wholesale Natural Gas			Other			Total Revenues
	2014
	Regulated Utilities	$	19,007		$	1,879		$	571		$	—		$	814		$	22,271
	International Energy	—			1,326			—			91			—			1,417
	Commercial Power	—			255			—			—			—			255
	Total Reportable Segments	$	19,007		$	3,460		$	571		$	91		$	814		$	23,943
	2013
	Regulated Utilities	$	17,837		$	1,720		$	506		$	—		$	847		$	20,910
	International Energy	—			1,447			—			99			—			1,546
	Commercial Power	—			260			—			—			—			260
	Total Reportable Segments	$	17,837		$	3,427		$	506		$	99		$	847		$	22,716
	2012
	Regulated Utilities	$	13,773		$	1,120		$	470		$	—		$	717		$	16,080
	International Energy	—			1,444			—			105			—			1,549
	Commercial Power	—			307			—			—			—			307
	Total Reportable Segments	$	13,773		$	2,871		$	470		$	105		$	717		$	17,936
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Business Segment Data	The remainder of Duke Energy Ohio’s operations is presented as Other. While it is not considered an operating segment, Other primarily includes certain governance costs allocated by its parent, Duke Energy. See Note 13 for additional information. All of Duke Energy Ohio’s revenues are generated domestically and its long-lived assets are all in the U.S.
		Year Ended December 31, 2014
	(in millions)	Regulated Utilities			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
	Unaffiliated revenues	$	1,894		$	19		$	1,913		$	—		$	—		$	1,913
	Intersegment revenues	1			—			1			—			(1		)	—
	Total revenues	$	1,895		$	19		$	1,914		$	—		$	(1	)	$	1,913
	Interest expense	$	81		$	5		$	86		$	—		$	—		$	86
	Depreciation and amortization	211			2			213			1			—			214
	Income tax expense (benefit)	117			(67		)	50			(7		)	—			43
	Segment income (loss)(a)	202			(121		)	81			(13		)	—			68
	Income from discontinued operations, net of tax																(563		)
	Net loss																$	(495	)
	Capital expenditures	$	300		$	22		$	322		$	—		$	—		$	322
	Segment assets	6,908			3,187			10,095			134			(230		)	9,999
	(a)	Commercial Power recorded a pretax impairment charge of $94 million related to OVEC. See Note 11 for additional information.
		Year Ended December 31, 2013
	(in millions)	Regulated Utilities			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
	Unaffiliated revenues	$	1,765		$	40		$	1,805		$	—		$	—		$	1,805
	Total revenues	$	1,765		$	40		$	1,805		$	—		$	—		$	1,805
	Interest expense	$	74		$	—		$	74		$	—		$	—		$	74
	Depreciation and amortization	200			13			213			—			—			213
	Income tax expense (benefit)	91			(36		)	55			(12		)	—			43
	Segment income (loss)	151			(65		)	86			(19		)	—			67
	Income from discontinued operations, net of tax																35
	Net income																$	102
	Capital expenditures	$	375		$	58		$	433		$	—		$	—		$	433
	Segment assets	6,649			4,170			10,819			99			(155		)	10,763
		Year Ended December 31, 2012
	(in millions)	Regulated Utilities			Commercial Power			Total Reportable Segments			Other			Eliminations			Total
	Unaffiliated revenues	$	1,745		$	75		$	1,820		$	—		$	—		$	1,820
	Intersegment revenues	1			1			2			—			(2		)	—
	Total revenues	$	1,746		$	76		$	1,822		$	—		$	(2	)	$	1,820
	Interest expense	$	61		$	28		$	89		$	—		$	—		$	89
	Depreciation and amortization	179			16			195			—			—			195
	Income tax expense (benefit)	91			(40		)	51			(18		)	—			33
	Segment income (loss)	159			(80		)	79			(34		)	—			45
	Income from discontinued operations, net of tax																130
	Net income																$	175
	Capital expenditures	$	427		$	87		$	514		$	—		$	—		$	514
	Segment assets	6,434			4,175			10,609			117			(166		)	10,560

Regulatory_Matters_Tables

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2014
Public Utilities, General Disclosures [Line Items]
Schedule of Regulatory Assets	The following tables present the regulatory assets and liabilities recorded on the Consolidated Balance Sheets.
		December 31, 2014
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Assets
	Asset retirement obligations	$	3,017	$	907	$	1,882		$	1,584	$	298	$	—	$	—
	Accrued pension and OPEB	2,015		412		812			354		458		132		217
	Retired generation facilities	1,659		58		1,545			152		1,393		—		56
	Debt fair value adjustment	1,305		—		—			—		—		—		—
	Net regulatory asset related to income taxes	1,144		614		354			141		213		64		111
	Hedge costs and other deferrals	628		103		490			217		273		7		28
	Demand side management (DSM)/Energy efficiency (EE)	330		106		203			193		10		21		—
	Grid Modernization	76		—		—			—		—		76		—
	Vacation accrual	213		86		46			46		—		6		12
	Deferred fuel	246		50		182			138		44		9		5
	Nuclear deferral	296		141		155			43		112		—		—
	Post-in-service carrying costs and deferred operating expenses	494		124		121			28		93		21		228
	Gasification services agreement buyout	55		—		—			—		—		—		55
	Transmission expansion obligation	70		—		—			—		—		74		—
	Manufactured gas plant (MGP)	115		—		—			—		—		115		—
	Other	494		263		109			66		42		36		66
	Total regulatory assets	12,157		2,864		5,899			2,962		2,936		561		778
	Less: current portion	1,115		399		491			287		203		49		93
	Total non-current regulatory assets	$	11,042	$	2,465	$	5,408		$	2,675	$	2,733	$	512	$	685
		December 31, 2013
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Assets
	Asset retirement obligations	$	1,608	$	123	786			$	389	$	397	$	—	$	—
	Accrued pension and OPEB	1,723		347		750			269		438		120		219
	Retired generation facilities	1,748		68		1,619			241		1,378		—		61
	Debt fair value adjustment	1,338		—		—			—		—		—		—
	Net regulatory asset related to income taxes	1,115		555		331			113		218		72		157
	Hedge costs and other deferrals	450		98		318			165		153		5		29
	DSM/EE	306		140		152			140		12		14		—
	Grid Modernization	65		—		—			—		—		65		—
	Vacation accrual	210		82		55			50		—		7		13
	Deferred fuel	94		—		37			6		31		14		43
	Nuclear deferral	262		40		222			77		145		—		—
	Post-in-service carrying costs and deferred operating expenses	459		150		137			19		118		21		151
	Gasification services agreement buyout	75		—		—			—		—		—		75
	Transmission expansion obligation	70		—		—			—		—		74		—
	MGP	90		—		—			—		—		90		—
	Other	473		219		101			42		60		46		87
	Total regulatory assets	10,086		1,822		4,508			1,511		2,950		528		835
	Less: current portion	895		295		353			127		221		57		118
	Total non-current regulatory assets	$	9,191	$	1,527	$	4,155		$	1,384	$	2,729	$	471	$	717
Schedule Of Regulatory Liabilities
		December 31, 2013
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Liabilities
	Costs of removal	$	5,308	$	2,423	$	2,008		$	1,637	$	371	$	241	$	645
	Amounts to be refunded to customers	151		—		120			—		120		—		31
	Storm reserve	145		20		125			—		125		—		—
	Accrued pension and OPEB	138		—		—			—		—		21		77
	Deferred fuel	177		45		132			—		132		—		—
	Other	346		153		114			99		14		27		45
	Total regulatory liabilities	6,265		2,641		2,499			1,736		762		289		798
	Less: current portion	316		65		207			63		144		27		16
	Total non-current regulatory liabilities	$	5,949	$	2,576	$	2,292		$	1,673	$	618	$	262	$	782
		December 31, 2014
	(in millions)	Duke Energy		Duke Energy Carolinas		Progress Energy			Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Regulatory Liabilities
	Costs of removal	$	5,221	$	2,420	$	1,975		$	1,692	$	283	$	222	$	613
	Amounts to be refunded to customers	166		—		70			—		70		—		96
	Storm reserve	150		25		125			—		125		—		—
	Accrued pension and OPEB	379		76		121			61		60		19		91
	Deferred fuel	37		6		23			23		—		—		8
	Other	444		217		171			127		44		10		42
	Total regulatory liabilities	6,397		2,744		2,485			1,903		582		251		850
	Less: current portion	204		34		106			71		35		10		54
	Total non-current regulatory liabilities	$	6,193	$	2,710	$	2,379		$	1,832	$	547	$	241	$	796
Schedule of Potential Plant Retirements	The table below contains the net carrying value of generating facilities planned for early retirement or being evaluated for potential retirement included in Net property, plant and equipment on the Consolidated Balance Sheets, excluding the Duke Energy Carolinas 170 MW Lee Unit 3 which is being converted to gas in 2015.
		31-Dec-14
		Duke Energy		Progress Energy(b)		Duke Energy Florida(b)			Duke Energy Ohio(c)		Duke Energy Indiana(d)
	Capacity (in MW)	1,704		873		873			163		668
	Remaining net book value (in millions)(a)	$	239	$	114	$	114		$	9	$	116
	(a)	Included in Net property, plant and equipment as of December 31, 2014, on the Consolidated Balance Sheets.
	(b)	Includes Crystal River Units 1 and 2.
	(c)	Includes Miami Fort Unit 6 which is expected to be retired by June 1, 2015.
	(d)	Includes Wabash River Units 2 through 6. Wabash River Unit 6 is being evaluated for potential conversion to gas. Duke Energy Indiana committed to retire or convert these units by June 2018 in conjunction with a settlement agreement associated with the Edwardsport air permit.
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Schedule of MISO Exit Fee Obligations	The following table provides a reconciliation of the beginning and ending balance of Duke Energy Ohio’s recorded obligations related to its withdrawal from MISO. As of December 31, 2014, $74 million is recorded as a Regulatory asset on Duke Energy Ohio's Consolidated Balance Sheets.
	(in millions)	31-Dec-13		Provision / Adjustments		Cash Reductions			31-Dec-14
	Duke Energy Ohio	$	95	$	3	$	(4	)	$	94

Commitments_and_Contingencies_

Commitments and Contingencies (Table)	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts Disclosure [Line Items]
Schedule of Additional Possible Losses in Excess of Recorded Environmental Reserves	Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are presented in the table below.
	(in millions)
	Duke Energy	$	89
	Duke Energy Carolinas	25
	Progress Energy	15
	Duke Energy Progress	1
	Duke Energy Florida	14
	Duke Energy Ohio	42
	Duke Energy Indiana	7
Schedule of Loss Contingencies	The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters discussed above, excluding asbestos related reserves. Reserves are classified on the Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Accounts payable and Other within Current Liabilities. The reasonably possible range of loss for all non-asbestos related matters in excess of recorded reserves is not material.
		December 31,
	(in millions)	2014				2013
	Reserves for Legal Matters
	Duke Energy	$	323			$	204
	Duke Energy Carolinas	72				—
	Progress Energy	93				78
	Duke Energy Progress	37				10
	Duke Energy Florida	36				43
Schedule of Purchase Obligations	The following table presents executory purchased power contracts, excluding contracts classified as leases. All contracts represent 100 percent of net plant output.
				Minimum Purchase Amount at December 31, 2014
	(in millions)	Contract Expiration		2015				2016			2017			2018				2019				Thereafter			Total
	Duke Energy Progress	2019-2022		$	59			60			$	61		$	62			$	63			$	93		$	398
	Duke Energy Florida	2023-2043		244				273			291			306				322				1,907			3,343
Schedule of Rent Expense	The following table presents rental expense for operating leases. These amounts are included in Operation, maintenance and other on the Consolidated Statements of Operations.
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Duke Energy	$	355			$	321			$	232
	Duke Energy Carolinas	41				39				38
	Progress Energy	257				225				232
	Duke Energy Progress	161				153				164
	Duke Energy Florida	96				72				68
	Duke Energy Ohio	17				14				14
	Duke Energy Indiana	21				22				20
Schedule of Future Minimum Rental Payments for Operating Leases	The following table presents future minimum lease payments under operating leases, which at inception had a non-cancelable term of more than one year.
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	2015	$	205			$	33			$	129		$	65			$	64			$	12		$	17
	2016	198				29				130			66				64				11			15
	2017	172				26				111			65				46				9			13
	2018	157				20				109			64				45				7			10
	2019	148				17				103			58				45				6			9
	Thereafter	938				64				709			421				288				18			9
	Total	$	1,818			$	189			$	1,291		$	739			$	552			$	63		$	73
Schedule of Future Minimum Lease Payments for Capital Leases	The following table presents future minimum lease payments under capital leases.
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	2015	$	178			$	6			$	46		$	21			$	26			$	7		$	4
	2016	188				6				47			21				26				7			4
	2017	190				7				47			21				26				3			2
	2018	198				7				48			22				26				4			2
	2019	208				8				51			25				26				2			2
	Thereafter	1,771				60				678			398				280				—			42
	Minimum annual payments	2,733				94				917			508				410				23			56
	Less: amount representing interest	(1,305		)		(67		)		(603		)	(361		)		(242		)		(3		)	(39		)
	Total	$	1,428			$	27			$	314		$	147			$	168			$	20		$	17
Reserve for Environmental Costs [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Schedule of Loss Contingencies	The following table contains information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheets.
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Balance at December 31, 2011	61			12			23			11		12			28			9
	Provisions / adjustments	39			1			19			5		14			5			3
	Cash reductions	(25	)		(1	)		(9	)		(2	)	(7	)		(18	)		(4	)
	Balance at December 31, 2012	75			12			33			14		19			15			8
	Provisions / adjustments	26			—			4			(1	)	5			20			1
	Cash reductions	(22	)		(1	)		(10	)		(5	)	(5	)		(8	)		(2	)
	Balance at December 31, 2013	79			11			27			8		19			27			7
	Provisions / adjustments	32			(1	)		1			4		(3	)		28			4
	Cash reductions	(14	)		—			(11	)		(7	)	(4	)		(1	)		(1	)
	Balance at December 31, 2014	97			10			17			5		12			54			10

Debt_and_Credit_Facilities_Tab

Debt and Credit Facilities (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule of Debt	The following tables show short-term obligations classified as long-term debt.
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Duke Energy Ohio				Duke Energy Indiana
	Tax-exempt bonds	$	347			$	35			$	27			$	285
	Commercial paper	475				300				25				150
	Secured debt(a)	200				—				—				—
	Total	$	1,022			$	335			$	52			$	435
		December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Duke Energy Ohio				Duke Energy Indiana
	Tax exempt bonds	$	471			$	75			$	111			$	285
	Commercial paper	450				300				—				150
	Secured debt(a)	200				—				—				—
	Total	$	1,121			$	375			$	111			$	435
	(a)	Instrument has a term of less than one year with the right to extend the maturity date for additional one-year periods with a final maturity date no later than December 2026.
	The following table shows the significant components of Current maturities of Long-Term Debt on the Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings.
	(in millions)	Maturity Date		Interest Rate			December 31, 2014
	Unsecured Debt
	Duke Energy (Parent)	Apr-15		3.35	%		$	450
	First Mortgage Bonds
	Duke Energy Ohio	Mar-15		0.375	%		150
	Duke Energy Progress	Apr-15		5.15	%		300
	Duke Energy Carolinas	Oct-15		5.3	%		500
	Duke Energy Florida	Nov-15		0.65	%		250
	Duke Energy Florida	Dec-15		5.1	%		300
	Duke Energy Progress	Dec-15		5.25	%		400
	Tax-exempt Bonds
	Duke Energy Progress	Jan-15		0.108	%		243
	Other						214
	Current maturities of long-term debt						$	2,807
	The following tables summarize outstanding debt.
		December 31, 2014
	(in millions)	Weighted Average Interest Rate			Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Unsecured debt, maturing 2015 - 2073	4.92	%		$	12,937		$	1,155		$	3,850		$	—		$	150		$	773		$	742
	Secured debt, maturing 2016 - 2037	2.5	%		2,806			400			525			300			225			—			—
	First mortgage bonds, maturing 2015 - 2044(a)	4.76	%		19,180			6,161			9,800			5,475			4,325			900			2,319
	Capital leases, maturing 2015 - 2051(b)	5.3	%		1,428			27			314			146			168			20			16
	Tax-exempt bonds, maturing 2015 - 2041(c)	2.13	%		1,296			355			291			291			—			77			573
	Notes payable and commercial paper(d)	0.7	%		2,989			—			—			—			—			—			—
	Money pool/intercompany borrowings				—			300			835			—			84			516			221
	Fair value hedge carrying value adjustment				8			8			—			—			—			—			—
	Unamortized debt discount and premium, net(e)				1,890			(15		)	(26		)	(11		)	(8		)	(29		)	(9		)
	Total debt	4.29	%		$	42,534		$	8,391		$	15,589		$	6,201		$	4,944		$	2,257		$	3,862
	Short-term notes payable and commercial paper				(2,514		)	—			—			—			—			—			—
	Short-term money pool borrowings				—			—			(835		)	—			(84		)	(491		)	(71		)
	Current maturities of long-term debt(f)				(2,807		)	(507		)	(1,507		)	(945		)	(562		)	(157		)	(5		)
	Total long-term debt(f)	4.58	%		$	37,213		$	7,884		$	13,247		$	5,256		$	4,298		$	1,609		$	3,786
	(a)    Substantially all electric utility property is mortgaged under mortgage bond indentures.
	(b)	Duke Energy includes $129 million and $787 million of capital lease purchase accounting adjustments related to Duke Energy Progress and Duke Energy Florida, respectively, related to power purchase agreements that are not accounted for as capital leases in their respective financial statements because of grandfathering provisions in GAAP.
	(c)	Substantially all tax-exempt bonds are secured by first mortgage bonds or letters of credit.
	(d)	Includes $475 million that was classified as Long-Term Debt on the Consolidated Balance Sheets due to the existence of long-term credit facilities that back-stop these commercial paper balances, along with Duke Energy’s ability and intent to refinance these balances on a long-term basis. The weighted-average days to maturity was 27 days.
	(e)	Duke Energy includes $1,975 million in purchase accounting adjustments related to the merger with Progress Energy. See Note 2 for additional information.
	(f)	Refer to Note 17 for additional information on amounts from consolidated VIE’s.
		December 31, 2013
	(in millions)	Weighted Average Interest Rate			Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Unsecured debt, maturing 2014 - 2073	5.18	%		$	13,550		$	1,157		$	4,150		$	—		$	150		$	805		$	744
	Secured debt, maturing 2014 - 2037	2.69	%		2,559			400			305			305			—			—			—
	First mortgage bonds, maturing 2015 - 2043(a)	4.9	%		17,831			6,161			8,450			4,125			4,325			900			2,319
	Capital leases, maturing 2014 - 2051(b)	5.23	%		1,516			30			327			148			179			27			20
	Other debt, maturing 2027	4.77	%		8			—			—			—			—			8			—
	Tax-exempt bonds, maturing 2014 - 2041(c)	1.28	%		2,356			395			910			669			241			479			573
	Notes payable and commercial paper(d)	1.02	%		1,289			—			—			—			—			—			—
	Money pool/intercompany borrowings				—			300			1,213			462			181			43			150
	Fair value hedge carrying value adjustment				9			9			—			—			—			—			—
	Unamortized debt discount and premium, net(e)				1,977			(16		)	(27		)	(12		)	(9		)	(31		)	(10		)
Total debt	4.52	%		$	41,095		$	8,436		$	15,328		$	5,697		$	5,067		$	2,231		$	3,796
Short-term notes payable and commercial paper				(839		)	—			—			—			—			—			—
Short-term money pool borrowings				—			—			(1,213		)	(462		)	(181		)	(43		)	—
Current maturities of long-term debt(f)				(2,104		)	(47		)	(485		)	(174		)	(11		)	(47		)	(5		)
Total long-term debt(f)	4.59	%		$	38,152		$	8,389		$	13,630		$	5,061		$	4,875		$	2,141		$	3,791
(a)    Substantially all electric utility property is mortgaged under mortgage bond indentures.
(b)	Duke Energy includes $144 million and $838 million of capital lease purchase accounting adjustments related to Duke Energy Progress and Duke Energy Florida, respectively, related to power purchase agreements that are not accounted for as capital leases in their respective financial statements because of grandfathering provisions in GAAP.
(c)	Substantially all tax-exempt bonds are secured by first mortgage bonds or letters of credit.
(d)	Includes $450 million that was classified as Long-Term Debt on the Consolidated Balance Sheets due to the existence of long-term credit facilities that back-stop these commercial paper balances, along with Duke Energy’s ability and intent to refinance these balances on a long-term basis. The weighted-average days to maturity was 49 days.
(e)	Duke Energy includes $2,067 million in purchase accounting adjustments related to the merger with Progress Energy. See Note 2 for additional information.
(f)	Refer to Note 17 for additional information on amounts from consolidated VIE’s.
Schedule of Maturities of Long-term Debt	The following table shows the annual maturities of long-term debt for the next five years and thereafter. Amounts presented exclude short-term notes payable and commercial paper and money pool borrowings for the Subsidiary Registrants.
		December 31, 2014
	(in millions)	Duke Energy(a)				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio				Duke Energy Indiana
	2015	$	2,793			$	507			$	1,507			$	945			$	562			$	157			$	5
	2016	2,980				756				614				302				12				57				480
	2017	2,452				116				940				453				487				3				3
	2018	3,207				1,505				515				3				512				28				153
	2019	2,810				5				1,418				606				12				552				62
	Thereafter	23,803				5,502				9,760				3,892				3,275				969				3,088
	Total long-term debt, including current maturities	$	38,045			$	8,391			$	14,754			$	6,201			$	4,860			$	1,766			$	3,791
	(a)	Excludes $1,975 million in purchase accounting adjustments related to the merger with Progress Energy. See Note 2 for additional information.
Schedule of Long-term Debt Instruments	The following tables summarize significant debt issuances (in millions).
							Year Ended December 31, 2014
	Issuance Date	Maturity Date		Interest Rate			Duke Energy (Parent)				Duke Energy Progress				Duke Energy Florida				Duke Energy
	Unsecured Debt
	April 2014(a)	Apr-24		3.75	%		600				—				—				600
	April 2014(a)(b)	Apr-17		0.613	%		400				—				—				400
	June 2014(c)	May-19		11.97	%		—				—				—				108
	June 2014(c)	May-21		13.68	%		—				—				—				110
	Secured Debt
	March 2014(d)	Mar-17		0.863	%		—				—				225				225
	July 2014(e)	Jul-36		5.34	%		—				—				—				129
	First Mortgage Bonds
	March 2014(f)	Mar-44		4.375	%		—				400				—				400
	March 2014(f)(g)	Mar-17		0.435	%		—				250				—				250
	November 2014(h)	Dec-44		4.15	%		—				500				—				500
	November 2014(g)(h)	Nov-17		0.432	%		—				200				—				200
	Total issuances						$	1,000			$	1,350			$	225			$	2,922
	(a)	Proceeds were used to redeem $402 million of tax-exempt bonds at Duke Energy Ohio, the repayment of outstanding commercial paper and for general corporate purposes. See Note 13 for additional information related to the redemption of Duke Energy Ohio's tax-exempt bonds.
	(b)	The debt is floating rate based on three-month London Interbank Offered Rate (LIBOR) plus a fixed credit spread of 38 basis points.
	(c)	Proceeds were used to repay $196 million of debt for International Energy and for general corporate purposes.
	(d)	Relates to the securitization of accounts receivable at a subsidiary of Duke Energy Florida. Proceeds were used to repay short-term borrowings under the intercompany money pool borrowing arrangement and for general corporate purposes. See Note 17 for further details.
	(e)	Proceeds were used to fund a portion of Duke Energy's prior investment in the existing Wind Star renewables portfolio.
	(f)	Proceeds were used to repay short-term borrowings under the intercompany money pool borrowing arrangement and for general corporate purposes.
	(g)	The debt is floating rate based on three-month LIBOR plus a fixed credit spread of 20 basis points.
	(h)	Proceeds will be used to redeem $450 million of tax-exempt bonds, repay short-term borrowings under the intercompany money pool borrowing arrangement and for general corporate purposes.
							Year Ended December 31, 2013
	Issuance Date	Maturity Date		Interest Rate			Duke Energy (Parent)				Duke Energy Progress				Duke Energy Ohio				Duke Energy Indiana				Duke Energy
	Unsecured Debt
	January 2013(a)	Jan-73		5.125	%		$	500			$	—			$	—			$	—			$	500
	June 2013(b)	Jun-18		2.1	%		500				—				—				—				500
	August 2013(c)(d)	Aug-23		11	%		―				—				—				—				220
	October 2013(e)	Oct-23		3.95	%		400				—				—				—				400
	Secured Debt
	February 2013(f)(g)	Dec-30		2.043	%		—				—				—				—				203
	February 2013(f)	Jun-37		4.74	%		—				—				—				—				220
	April 2013(h)	Apr-26		5.456	%		—				—				—				—				230
	December 2013(i)	Dec-16		0.852	%		—				300				—				—				300
	First Mortgage Bonds
	March 2013(j)	Mar-43		4.1	%		—				500				—				—				500
	July 2013(k)	Jul-43		4.9	%		—				—				—				350				350
	July 2013(k)(l)	Jul-16		0.619	%		—				—				—				150				150
	September 2013(m)	Sep-23		3.8	%		—				—				300				—				300
	September 2013(m)(n)	Mar-15		0.4	%		—				—				150				—				150
	Total issuances						$	1,400			$	800			$	450			$	500			$	4,023
	(a)	Callable after January 2018 at par. Proceeds were used to redeem the $300 million 7.10% Cumulative Quarterly Income Preferred Securities (QUIPS) and to repay a portion of outstanding commercial paper and for general corporate purposes.
	(b)	Proceeds were used to repay $250 million of current maturities and for general corporate purposes, including the repayment of outstanding commercial paper.
	(c)	Proceeds were used to repay $200 million of current maturities. The maturity date included above applies to half of the instrument. The remaining half matures in August 2018.
	(d)	The debt is floating rate based on a consumer price index and an overnight funds rate in Brazil. The debt is denominated in Brazilian Real.
	(e)	Proceeds were used to repay commercial paper as well as for general corporate purposes.
	(f)	Represents the conversion of construction loans related to two renewable energy projects issued in December 2012 to term loans. No cash proceeds were received in conjunction with the conversion. The term loans have varying maturity dates. The maturity date presented represents the latest date for all components of the respective loans.
	(g)	The debt is floating rate. Duke Energy has entered into a pay fixed-receive floating interest rate swap for 95 percent of the loans.
	(h)	Represents the conversion of a $190 million bridge loan issued in conjunction with the acquisition of Ibener in December 2012. Duke Energy received incremental proceeds of $40 million upon conversion of the bridge loan. The debt is floating rate and is denominated in U.S. dollars. Duke Energy has entered into a pay fixed-receive floating interest rate swap for 75 percent of the loan.
	(i)	Relates to the securitization of accounts receivable at a subsidiary of Duke Energy Progress; the proceeds were used to repay short-term debt. See Note 17 for further details.
	(j)	Proceeds were used to repay notes payable to affiliated companies as well as for general corporate purposes.
	(k)	Proceeds were used to repay $400 million of current maturities.
	(l)	The debt is floating rate based on three-month LIBOR and a fixed credit spread of 35 basis points.
	(m)	Proceeds were used for general corporate purposes including the repayment of short-term notes payable, a portion of which was incurred to fund the retirement of $250 million of first mortgage bonds that matured in the first half of 2013.
	(n)	The debt is floating rate based on three-month LIBOR plus a fixed credit spread of 14 basis points.
Schedule Of Line Of Credit Facilities	The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility.
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy (Parent)				Duke Energy Carolinas				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio				Duke Energy Indiana
	Facility size(a)	$	6,000			$	2,250			$	1,000			$	750			$	650			$	650			$	700
	Reduction to backstop issuances
	Commercial paper(b)	(2,021		)		(1,479		)		(300		)		—				(29		)		(38		)		(175		)
	Outstanding letters of credit	(70		)		(62		)		(4		)		(2		)		(1		)		—				(1		)
	Tax-exempt bonds	(116		)		—				(35		)		—				—				—				(81		)
	Available capacity	$	3,793			$	709			$	661			$	748			$	620			$	612			$	443
	(a)	Represents the sublimit of each borrower.
	(b)	Duke Energy issued $475 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies in the Consolidated Balance Sheets.

Guarantees_and_Indemnification1

Guarantees and Indemnifications (Tables)	12 Months Ended
	Dec. 31, 2014
Guarantor Obligations [Line Items]
Schedule of Guarantor Obligations	The following table includes the liabilities recognized for the guarantees discussed above. These amounts are primarily recorded in Other within Deferred Credits and other Liabilities on the Consolidated Balance Sheets. As current estimates change, additional losses related to guarantees and indemnifications to third parties, which could be material, may be recorded by the Duke Energy Registrants in the future.
		December 31,
		2014		2013
	Duke Energy	$	28	$	24
	Progress Energy	13		9
	Duke Energy Florida	7		3

Joint_Ownership_of_Generating_1

Joint Ownership of Generating and Transmission Facilities (Tables)	12 Months Ended
	Dec. 31, 2014
Jointly Owned Utility Plant Interests [Line Items]
Schedule Joint Ownership of Generating and Transmission Facilities	The following table presents the share of jointly owned plant or facilities included on the Consolidated Balance Sheets. All facilities are operated by the Duke Energy Registrants unless otherwise noted.
		December 31, 2014
		Ownership Share		Property, Plant and Equipment		Accumulated Depreciation		Construction Work in Progress
	Duke Energy Carolinas
	Catawba Nuclear Station (Units 1 and 2)(a)(b)	19.25	%	$	886	$	534	$	29
	Duke Energy Progress
	Mayo Station(a)(c)	83.83	%	1,111		360		10
	Shearon Harris Nuclear Station(a)(c)	83.83	%	3,872		2,242		208
	Brunswick Nuclear Station(a)(c)	81.67	%	2,673		1,372		290
	Roxboro Station (Unit 4)(a)(c)	87.06	%	954		514		24
	Duke Energy Florida
	Crystal River Nuclear Station (Unit 3)(a)(d)	91.78	%	—		—		—
	Intercession City Station (Unit P11)(a)	(e)		24		14		—
	Duke Energy Ohio
	Miami Fort Station (Units 7 and 8)(f)(g)	64	%	—		—		—
	J.M. Stuart Station(f)(h)(i)	39	%	—		—		—
	Conesville Station (Unit 4)(f)(h)(i)	40	%	—		—		—
	W.M. Zimmer Station(f)(h)	46.5	%	—		—		—
	Killen Station(f)(g)(i)	33	%	—		—		—
	Transmission facilities(a)(h)	Various		96		51		1
	Duke Energy Indiana
	Gibson Station (Unit 5)(a)(j)	50.05	%	315		170		6
	Vermillion(a)(k)	62.5	%	154		105		—
	Transmission and local facilities(a)(j)	Various		3,918		1,633		—
	International Energy
	Brazil - Canoas I and II(l)	47.2	%	235		78		—
	(a)	Included in Regulated Utilities segment.
	(b)	Jointly owned with North Carolina Municipal Power Agency Number 1, NCEMC and Piedmont Municipal Power Agency.
	(c)	Jointly owned with NCEMPA. Duke Energy Progress executed an agreement in September 2014 to purchase NCEMPA's ownership interest in these facilities. See Note 2 for further discussion.
	(d)	All costs associated with Crystal River Unit 3 are included within Regulatory assets on the Consolidated Balance Sheets of Duke Energy, Progress Energy and Duke Energy Florida. See Note 4 for additional information. Co-owned with Seminole Electric Cooperative, Inc., City of Ocala, Orlando Utilities Commission, City of Gainesville, City of Leesburg, Kissimmee Utility Authority, Utilities Commission of the City of New Smyrna Beach, City of Alachua and City of Bushnell (Florida Municipal Joint Owners). Duke Energy Florida is in the process of obtaining the remaining ownership interest from the Florida Municipal Joint Owners.
	(e)	Jointly owned with Georgia Power Company (GPC). GPC has exclusive rights to the output of the unit during the months of June through September and pays all fuel and water costs during this period. Duke Energy Florida pays all fuel and water costs during the remaining months. Other costs are allocated 66.67 percent to Duke Energy Florida and the remainder to GPC.
	(f)	All costs associated with these plants are included in Assets held for sale on the Consolidated Balance Sheets of Duke Energy and Duke Energy Ohio as part of the Disposal Group. See Note 2 for further discussion.
	(g)	Jointly owned with The Dayton Power and Light Company.
	(h)	Jointly owned with America Electric Power Generation Resources and The Dayton Power and Light Company.
	(i)	Station is not operated by Duke Energy Ohio.
	(j)	Jointly owned with WVPA and Indiana Municipal Power Agency.
	(k)	Jointly owned with WVPA.
	(l)	Included in International Energy segment. Jointly owned with Companhia Brasileira de Aluminio.

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation [Line Items]
Schedule of Asset Retirement Obligations	The following table presents changes in the liability associated with asset retirement obligations.
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Balance at December 31, 2012(a)	$	5,176		$	1,959		$	2,420		$	1,656	$	764		$	28		$	37
	Acquisitions	4			—			—			—		—			—			—
	Accretion expense(b)	239			122			113			80		33			2			—
	Liabilities settled	(12		)	—			(12		)	—		(12		)	—			—
	Revisions in estimates of cash flows(c)	(449		)	(487		)	49			1		48			(2		)	(7		)
	Balance at December 31, 2013(a)	4,958			1,594			2,570			1,737		833			28			30
	Acquisitions	4			—			—			—		—			—			—
	Accretion expense(b)	246			113			135			97		38			2			2
	Liabilities settled(d)	(68		)	—			(68		)	—		(68		)	—			—
	Liabilities incurred in the current year(e)	3,500			1,717			1,783			1,783		—			—			—
	Revisions in estimates of cash flows(c)	(174		)	4			291			288		3			(3		)	—
	Balance at December 31, 2014	$	8,466		$	3,428		$	4,711		$	3,905	$	806		$	27		$	32
	(a)	Balances at December 31, 2013 and 2012, include $8 million and $7 million, respectively, reported in Other current liabilities on the Consolidated Balance Sheets at Duke Energy, Progress Energy and Duke Energy Progress.
	(b)	Substantially all accretion expense for the years ended December 31, 2014 and 2013 relates to Duke Energy’s regulated electric operations and has been deferred in accordance with regulatory accounting treatment.
	(c)	For 2014, amounts for Duke Energy, Progress Energy and Duke Energy Progress primarily relate to Duke Energy Progress' site-specific nuclear decommissioning cost studies. Amounts at Duke Energy also include impacts from Duke Energy Progress' site-specific nuclear decommissioning cost studies on purchase accounting amounts. For 2013, amounts for Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Florida primarily relate to the site-specific nuclear decommissioning cost studies.
	(d)	Amounts relate to liability settlements for Crystal River Unit 3.
	(e)	Amounts primarily relate to asset retirement obligations recorded as a result of the Coal Ash Act and an agreement with the SCDHEC related to the W.S. Lee Steam Station.
Public Utilities General Disclosures	The following table summarizes information about nuclear decommissioning cost studies.
	(in millions)	Annual Funding Requirement			Decommissioning Costs(a)(b)(c)			Year of Cost Study
	Duke Energy Carolinas(d)	$	21		$	3,420		2013
	Duke Energy Progress(e)	14			3,062			2014
	Duke Energy Florida	—			1,083			2013
	(a)	Represents cost per the most recent site-specific nuclear decommissioning cost studies, including costs to decommission plant components not subject to radioactive contamination.
	(b)	Includes the Subsidiary Registrants' ownership interest in jointly owned reactors. Other joint owners are responsible for decommissioning costs related to their interest in the reactors.
	(c)	Amounts are in dollars of year of cost study.
	(d)	In the fourth quarter of 2014, Duke Energy Carolinas requested from the NCUC a reduction in the annual funding requirement to zero. Duke Energy Carolinas received approval from the NCUC in January 2015.
	(e)	Duke Energy Progress' site-specific cost nuclear decommissioning cost studies are expected to be filed with the NCUC and PSCSC by the second quarter of 2015. Duke Energy Progress will also complete a new funding study, which will be completed and filed with the NCUC and PSCSC in 2015.
	Operating licenses for nuclear units are potentially subject to extension. The following table includes the current expiration of nuclear operating licenses.
	Unit	Year of Expiration
	Duke Energy Carolinas
	Catawba Unit 1	2043
	Catawba Unit 2	2043
	McGuire Unit 1	2041
	McGuire Unit 2	2043
	Oconee Unit 1	2033
	Oconee Unit 2	2033
	Oconee Unit 3	2034
	Duke Energy Progress
	Brunswick Unit 1	2036
	Brunswick Unit 2	2034
	Harris	2046
	Robinson	2030
	Duke Energy Florida
	Crystal River Unit 3	(a)
	(a)	Duke Energy Florida has requested the NRC terminate the operating license as Crystal River Unit 3 permanently ceased operation in February 2013. Refer to Note 4 for further information on decommissioning activity and transition to SAFSTOR.

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Public Utility, Property, Plant and Equipment [Line Items]
Schedule Of Property, Plant And Equipment	The composite weighted-average depreciation rates, excluding nuclear fuel, are included in the table that follows.
		Years Ended December 31,
		2014			2013			2012
	Duke Energy	2.8	%		2.8	%		2.9	%
	Duke Energy Carolinas	2.7	%		2.8	%		2.8	%
	Progress Energy	2.5	%		2.5	%		2.6	%
	Duke Energy Progress	2.5	%		2.5	%		2.7	%
	Duke Energy Florida	2.7	%		2.4	%		2.5	%
	Duke Energy Ohio	2.3	%		3.3	%		3.2	%
	Duke Energy Indiana	3	%		2.8	%		3.3	%
	The following tables summarize the property, plant and equipment.
		31-Dec-14
	(in millions)	Estimated Useful Life (Years)		Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Land			$	1,459			$	403			$	704		$	380		$	324		$	114		$	108
	Plant - Regulated
	Electric generation, distribution and transmission	2 - 138		82,206				31,751				33,672			20,616			13,056			3,956			11,911
	Natural gas transmission and distribution	Dec-67		2,230				—				—			—			—			2,230			—
	Other buildings and improvements	9 - 100		1,445				465				607			286			318			200			173
	Plant - Nonregulated
	Electric generation, distribution and transmission	30-Jan		2,380				—				—			—			—			—			—
	Other buildings and improvements	May-50		2,498				—				—			—			—			—			—
	Nuclear fuel			2,865				1,676				1,190			1,190			—			—			—
	Equipment	Mar-34		1,762				341				506			388			118			330			166
	Construction in process			4,519				2,081				1,215			908			307			97			481
	Other	May-80		3,497				655				756			439			310			214			195
	Total property, plant and equipment(a)(d)			104,861				37,372				38,650			24,207			14,433			7,141			13,034
	Total accumulated depreciation - regulated(b)(c)(d)			(32,628		)		(12,700		)		(13,506		)	(9,021		)	(4,478		)	(2,213		)	(4,219		)
	Total accumulated depreciation - nonregulated(c)(d)			(2,196		)		—				—			—			—			—			—
	Generation facilities to be retired, net			9				—				—			—			—			9			—
	Total net property, plant and equipment			$	70,046			$	24,672			$	25,144		$	15,186		$	9,955		$	4,937		$	8,815
	(a)	Includes capitalized leases of $1,548 million, $40 million, $315 million, $146 million, $169 million, $98 million, and $30 million at Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, and Duke Energy Indiana, respectively, primarily in regulated plant. The Progress Energy, Duke Energy Progress and Duke Energy Florida amounts are net of $72 million, $5 million and $67 million, respectively, of accumulated amortization of capitalized leases.
	(b)	Includes $1,408 million, $847 million, $561 million and $561 million of accumulated amortization of nuclear fuel at Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Progress, respectively.
	(c)	Includes accumulated amortization of capitalized leases of $52 million, $8 million, $25 million and $6 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana, respectively.
	(d)	Includes gross property, plant and equipment cost of consolidated VIEs of $1,873 million and accumulated depreciation of consolidated VIEs of $257 million at Duke Energy.
		31-Dec-13
	(in millions)	Estimated Useful Life (Years)		Duke Energy				Duke Energy Carolinas				Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Land			$	1,481			$	397			$	705		$	383		$	321		$	137		$	105
	Plant - Regulated
	Electric generation, distribution and transmission	2 - 125		78,272				30,018				31,792			19,190			12,601			3,925			11,594
	Natural gas transmission and distribution	Dec-67		2,138				—				—			—			—			2,138			—
	Other buildings and improvements	2 - 100		1,397				447				610			282			315			190			159
	Plant - Nonregulated
	Electric generation, distribution and transmission	2 - 100		6,267				—				—			—			—			4,017			—
	Other buildings and improvements	9 -100		2,512				—				—			—			—			5			—
	Nuclear fuel			2,458				1,446				1,012			1,012			—			—			—
	Equipment	Jan-33		1,557				287				621			357			94			317			146
	Construction in process			3,595				1,741				873			631			238			166			307
	Other	May-33		3,438				570				867			418			294			248			178
	Total property, plant and equipment(a)(d)			103,115				34,906				36,480			22,273			13,863			11,143			12,489
	Total accumulated depreciation - regulated(b)(c)(d)			(31,659		)		(11,894		)		(13,098		)	(8,623		)	(4,252		)	(2,160		)	(3,913		)
	Total accumulated depreciation - nonregulated(c)(d)			(1,966		)		—				—			—			—			(748		)	—
	Total net property, plant and equipment			$	69,490			$	23,012			$	23,382		$	13,650		$	9,611		$	8,235		$	8,576
	(a)	Includes capitalized leases of $1,606 million, $53 million, $328 million, $148 million, $180 million, $96 million, and $30 million at Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, and Duke Energy Indiana, respectively, primarily in regulated plant. The Progress Energy, Duke Energy Progress and Duke Energy Florida amounts are net of $60 million, an insignificant amount and $57 million, respectively, of accumulated amortization of capitalized leases.
	(b)	Includes $1,118 million, $681 million, $438 million and $438 million of accumulated amortization of nuclear fuel at Duke Energy, Duke Energy Carolinas, Progress Energy and Duke Energy Progress, respectively.
	(c)	Includes accumulated amortization of capitalized leases of $40 million, $4 million, $21 million and $5 million at Duke Energy, Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana, respectively.
	(d)	Includes gross property, plant and equipment cost of consolidated VIEs of $1,678 million and accumulated depreciation of consolidated VIEs of $175 million at Duke Energy.
Schedule Of Capitalized Interest	The following table presents capitalized interest, which includes the debt component of AFUDC.
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Duke Energy	$	75			$	89			$	176
	Duke Energy Carolinas	38				41				72
	Progress Energy	11				19				41
	Duke Energy Progress	10				16				23
	Duke Energy Florida	1				3				18
	Duke Energy Ohio	10				11				13
	Duke Energy Indiana	6				9				39

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill [Line Items]
Goodwill By Reportable Operating Segment	Duke Energy
	(in millions)	Regulated Utilities			International Energy			Commercial Power			Total
	Balance at December 31, 2013
	Goodwill	$	15,950		$	326		$	935		$	17,211
	Accumulated impairment charges	—			—			(871		)	(871		)
	Balance at December 31, 2013, net of accumulated impairment charges	15,950			326			64			16,340
	Foreign exchange and other changes	—			(19		)	—			(19		)
	Balance at December 31, 2014
	Goodwill	15,950			307			935			17,192
	Accumulated impairment charges	—			—			(871		)	(871		)
	Balance at December 31, 2014, net of accumulated impairment charges	$	15,950		$	307		$	64		$	16,321
Schedule of Intangible Assets	The following tables show the carrying amount and accumulated amortization of intangible assets within Other on the Consolidated Balance Sheets of the Duke Energy Registrants at December 31, 2014 and 2013.
		December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida		Duke Energy Ohio (a)			Duke Energy Indiana
	Emission allowances	$	23		$	1		$	7		$	3		$	4	$	—		$	16
	Renewable energy certificates	97			25			69			69			—		3			—
	Gas, coal and power contracts	24			—			—			—			—		—			24
	Wind development rights	97			—			—			—			—		—			—
	Other	76			—			—			—			—		—			—
	Total gross carrying amounts	317			26			76			72			4		3			40
	Accumulated amortization - gas, coal and power contracts	(15		)	—			—			—			—		—			(15		)
	Accumulated amortization - wind development rights	(14		)	—			—			—			—		—			—
	Accumulated amortization - other	(25		)	—			—			—			—		—			—
	Total accumulated amortization	(54		)	—			—			—			—		—			(15		)
	Total intangible assets, net	$	263		$	26		$	76		$	72		$	4	$	3		$	25
	(a)	During 2014, Duke Energy Ohio reduced the carrying amount of OVEC to zero. A charge of $94 million is recorded in Impairment Charges on Duke Energy Ohio's Consolidated Statement of Operations. In addition, Duke Energy Ohio has emission allowances and renewable energy certificates that have been reclassified to Assets Held For Sale pending the sale of the Disposal Group. See Note 17 for further information.
		December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Emission allowances	$	63		$	1		$	21		$	3		$	18	$	20		$	21
	Renewable energy certificates	82			16			64			64			—		2			—
	Gas, coal and power contracts	180			—			—			—			—		156			24
	Wind development rights	86			—			—			—			—		—			—
	Other	76			—			—			—			—		—			—
	Total gross carrying amounts	487			17			85			67			18		178			45
	Accumulated amortization - gas, coal and power contracts	(73		)	—			—			—			—		(60		)	(13		)
	Accumulated amortization - wind development rights	(12		)	—			—			—			—		—			—
	Accumulated amortization - other	(24		)	—			—			—			—		—			—
	Total accumulated amortization	(109		)	—			—			—			—		(60		)	(13		)
	Total intangible assets, net	$	378		$	17		$	85		$	67		$	18	$	118		$	32
Schedule of Amortization Expense	The following table presents amortization expense for gas, coal and power contracts, wind development rights and other intangible assets.
		December 31,
	(in millions)	2014			2013			2012
	Duke Energy	$	6		$	13		$	14
	Duke Energy Ohio	2			8			12
	Duke Energy Indiana	1			1			1
Schedule of Expected Amortization Expense	The amortization amounts discussed below are estimates and actual amounts may differ from these estimates due to such factors as changes in consumption patterns, sales or impairments of emission allowances or other intangible assets, delays in the in-service dates of wind assets, additional intangible acquisitions and other events.
	(in millions)	2015			2016			2017			2018			2019
	Duke Energy	$	11		$	8		$	7		$	7		$	7
	Duke Energy Ohio	2			1			1			1			1
	Duke Energy Indiana	5			3			2			2			2
Duke Energy Ohio [Member]
Goodwill [Line Items]
Goodwill By Reportable Operating Segment
	(in millions)	Regulated Utilities			Commercial Power			Total
	Balance at December 31, 2013
	Goodwill	$	1,136		$	1,188		$	2,324
	Accumulated impairment charges	(216		)	(1,188		)	(1,404		)
	Balance at December 31, 2013, net of accumulated impairment charges	920			—			920
	Balance at December 31, 2014
	Goodwill	1,136			1,188			2,324
	Accumulated impairment charges	(216		)	(1,188		)	(1,404		)
	Balance at December 31, 2014, net of accumulated impairment charges	$	920		$	—		$	920

Investments_in_Unconsolidated_1

Investments in Unconsolidated Affiliates (Tables)	12 Months Ended
	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Investments in Equity Method Unconsolidated Affiliates	The following table presents Duke Energy’s investments in unconsolidated affiliates accounted for under the equity method, as well as the respective equity in earnings, by segment.
		Years Ended December 31,
		2014					2013					2012
	(in millions)	Investments		Equity in earnings			Investments		Equity in earnings			Equity in earnings
	Regulated Utilities	$	3	$	(3	)	$	4	$	(1	)	$	(5	)
	International Energy	69		120			82		110			134
	Commercial Power	258		10			252		7			14
	Other	28		3			52		6			5
	Total	$	358	$	130		$	390	$	122		$	148

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Consolidated Statements of Operations and Comprehensive Income are presented in the following table.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Duke Energy Carolinas
	Corporate governance and shared service expenses(a)	$	851	$	927	$	1,112
	Indemnification coverages(b)	21		22		21
	JDA revenue(c)	133		121		18
	JDA expense(c)	198		116		91
	Progress Energy
	Corporate governance and shared services provided by Duke Energy(a)	$	732	$	290	$	63
	Corporate governance and shared services provided to Duke Energy(d)	—		96		47
	Indemnification coverages(b)	33		34		17
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Progress
	Corporate governance and shared service expenses(a)	$	386	$	266	$	254
	Indemnification coverages(b)	17		20		8
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Florida
	Corporate governance and shared service expenses(a)	$	346	$	182	$	186
	Indemnification coverages(b)	16		14		8
	Duke Energy Ohio
	Corporate governance and shared service expenses(a)	$	316	$	347	$	358
	Indemnification coverages(b)	13		15		15
	Duke Energy Indiana
	Corporate governance and shared service expenses(a)	$	384	$	422	$	419
	Indemnification coverages(b)	11		14		8
	(a)	The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(b)	The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(c)	Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Consolidated Statements of Operations and Comprehensive Income.
	(d)	In 2013 and 2012, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Consolidated Statements of Changes in Common Stockholder's Equity.
Progress Energy [Member]
Related Party Transaction [Line Items]
Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Consolidated Statements of Operations and Comprehensive Income are presented in the following table.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Duke Energy Carolinas
	Corporate governance and shared service expenses(a)	$	851	$	927	$	1,112
	Indemnification coverages(b)	21		22		21
	JDA revenue(c)	133		121		18
	JDA expense(c)	198		116		91
	Progress Energy
	Corporate governance and shared services provided by Duke Energy(a)	$	732	$	290	$	63
	Corporate governance and shared services provided to Duke Energy(d)	—		96		47
	Indemnification coverages(b)	33		34		17
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Progress
	Corporate governance and shared service expenses(a)	$	386	$	266	$	254
	Indemnification coverages(b)	17		20		8
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Florida
	Corporate governance and shared service expenses(a)	$	346	$	182	$	186
	Indemnification coverages(b)	16		14		8
	Duke Energy Ohio
	Corporate governance and shared service expenses(a)	$	316	$	347	$	358
	Indemnification coverages(b)	13		15		15
	Duke Energy Indiana
	Corporate governance and shared service expenses(a)	$	384	$	422	$	419
	Indemnification coverages(b)	11		14		8
	(a)	The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(b)	The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(c)	Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Consolidated Statements of Operations and Comprehensive Income.
	(d)	In 2013 and 2012, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Consolidated Statements of Changes in Common Stockholder's Equity.
Duke Energy Progress [Member]
Related Party Transaction [Line Items]
Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Consolidated Statements of Operations and Comprehensive Income are presented in the following table.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Duke Energy Carolinas
	Corporate governance and shared service expenses(a)	$	851	$	927	$	1,112
	Indemnification coverages(b)	21		22		21
	JDA revenue(c)	133		121		18
	JDA expense(c)	198		116		91
	Progress Energy
	Corporate governance and shared services provided by Duke Energy(a)	$	732	$	290	$	63
	Corporate governance and shared services provided to Duke Energy(d)	—		96		47
	Indemnification coverages(b)	33		34		17
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Progress
	Corporate governance and shared service expenses(a)	$	386	$	266	$	254
	Indemnification coverages(b)	17		20		8
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Florida
	Corporate governance and shared service expenses(a)	$	346	$	182	$	186
	Indemnification coverages(b)	16		14		8
	Duke Energy Ohio
	Corporate governance and shared service expenses(a)	$	316	$	347	$	358
	Indemnification coverages(b)	13		15		15
	Duke Energy Indiana
	Corporate governance and shared service expenses(a)	$	384	$	422	$	419
	Indemnification coverages(b)	11		14		8
	(a)	The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(b)	The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(c)	Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Consolidated Statements of Operations and Comprehensive Income.
	(d)	In 2013 and 2012, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Consolidated Statements of Changes in Common Stockholder's Equity.
Duke Energy Florida [Member]
Related Party Transaction [Line Items]
Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Consolidated Statements of Operations and Comprehensive Income are presented in the following table.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Duke Energy Carolinas
	Corporate governance and shared service expenses(a)	$	851	$	927	$	1,112
	Indemnification coverages(b)	21		22		21
	JDA revenue(c)	133		121		18
	JDA expense(c)	198		116		91
	Progress Energy
	Corporate governance and shared services provided by Duke Energy(a)	$	732	$	290	$	63
	Corporate governance and shared services provided to Duke Energy(d)	—		96		47
	Indemnification coverages(b)	33		34		17
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Progress
	Corporate governance and shared service expenses(a)	$	386	$	266	$	254
	Indemnification coverages(b)	17		20		8
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Florida
	Corporate governance and shared service expenses(a)	$	346	$	182	$	186
	Indemnification coverages(b)	16		14		8
	Duke Energy Ohio
	Corporate governance and shared service expenses(a)	$	316	$	347	$	358
	Indemnification coverages(b)	13		15		15
	Duke Energy Indiana
	Corporate governance and shared service expenses(a)	$	384	$	422	$	419
	Indemnification coverages(b)	11		14		8
	(a)	The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(b)	The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(c)	Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Consolidated Statements of Operations and Comprehensive Income.
	(d)	In 2013 and 2012, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Consolidated Statements of Changes in Common Stockholder's Equity.
Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Consolidated Statements of Operations and Comprehensive Income are presented in the following table.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Duke Energy Carolinas
	Corporate governance and shared service expenses(a)	$	851	$	927	$	1,112
	Indemnification coverages(b)	21		22		21
	JDA revenue(c)	133		121		18
	JDA expense(c)	198		116		91
	Progress Energy
	Corporate governance and shared services provided by Duke Energy(a)	$	732	$	290	$	63
	Corporate governance and shared services provided to Duke Energy(d)	—		96		47
	Indemnification coverages(b)	33		34		17
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Progress
	Corporate governance and shared service expenses(a)	$	386	$	266	$	254
	Indemnification coverages(b)	17		20		8
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Florida
	Corporate governance and shared service expenses(a)	$	346	$	182	$	186
	Indemnification coverages(b)	16		14		8
	Duke Energy Ohio
	Corporate governance and shared service expenses(a)	$	316	$	347	$	358
	Indemnification coverages(b)	13		15		15
	Duke Energy Indiana
	Corporate governance and shared service expenses(a)	$	384	$	422	$	419
	Indemnification coverages(b)	11		14		8
	(a)	The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(b)	The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(c)	Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Consolidated Statements of Operations and Comprehensive Income.
	(d)	In 2013 and 2012, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Consolidated Statements of Changes in Common Stockholder's Equity.
Duke Energy Indiana [Member]
Related Party Transaction [Line Items]
Related Party Transactions, Other Revenue and Expense	Material amounts related to transactions with related parties included in the Consolidated Statements of Operations and Comprehensive Income are presented in the following table.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Duke Energy Carolinas
	Corporate governance and shared service expenses(a)	$	851	$	927	$	1,112
	Indemnification coverages(b)	21		22		21
	JDA revenue(c)	133		121		18
	JDA expense(c)	198		116		91
	Progress Energy
	Corporate governance and shared services provided by Duke Energy(a)	$	732	$	290	$	63
	Corporate governance and shared services provided to Duke Energy(d)	—		96		47
	Indemnification coverages(b)	33		34		17
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Progress
	Corporate governance and shared service expenses(a)	$	386	$	266	$	254
	Indemnification coverages(b)	17		20		8
	JDA revenue(c)	198		116		91
	JDA expense(c)	133		121		18
	Duke Energy Florida
	Corporate governance and shared service expenses(a)	$	346	$	182	$	186
	Indemnification coverages(b)	16		14		8
	Duke Energy Ohio
	Corporate governance and shared service expenses(a)	$	316	$	347	$	358
	Indemnification coverages(b)	13		15		15
	Duke Energy Indiana
	Corporate governance and shared service expenses(a)	$	384	$	422	$	419
	Indemnification coverages(b)	11		14		8
	(a)	The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These amounts are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(b)	The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Consolidated Statements of Operations and Comprehensive Income.
	(c)	Duke Energy Carolinas and Duke Energy Progress participate in a JDA which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power under the JDA are recorded in Operating Revenues on the Consolidated Statements of Operations and Comprehensive Income. Expenses from the purchase of power under the JDA are recorded in Fuel used in electric generation and purchased power on the Consolidated Statements of Operations and Comprehensive Income.
	(d)	In 2013 and 2012, Progress Energy Service Company (PESC), a consolidated subsidiary of Progress Energy, charged a proportionate share of corporate governance and other costs to consolidated affiliates of Duke Energy. Corporate governance and other shared costs were primarily related to human resources, employee benefits, legal and accounting fees, as well as other third-party costs. These charges were recorded as an offset to Operation, maintenance and other in the Consolidated Statements of Operations and Comprehensive Income. Effective January 1, 2014, PESC was contributed to Duke Energy Corporate Services (DECS), a consolidated subsidiary of Duke Energy, and these costs were no longer charged out of Progress Energy. Progress Energy recorded a non-cash after-tax equity transfer related to the contribution of PESC to DECS in its Consolidated Statements of Changes in Common Stockholder's Equity.

Derivatives_and_Hedging_Tables

Derivatives and Hedging (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative [Line Items]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk	The following tables show notional amounts for derivatives related to interest rate risk.
		December 31, 2014										December 31, 2013
	(in millions)	Duke				Duke			Duke			Duke				Duke
		Energy				Energy Florida			Energy			Energy				Energy
									Ohio							Ohio
	Cash flow hedges(a)	$	750			$	—		$	—		$	798			$	—
	Undesignated contracts	277				250			27			34				27
	Total notional amount	$	1,027			250			$	27		$	832			$	27
	(a)	Duke Energy includes amounts related to consolidated VIEs of $541 million at December 31, 2014 and $584 million at December 31, 2013
Underlying Notional Amounts for Commodity Derivative Instruments Accounted for at Fair Value	The tables below show information relating to volumes of outstanding commodity derivatives. Amounts disclosed represent the notional volumes of commodity contracts excluding NPNS. Amounts disclosed represent the absolute value of notional amounts. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown.
		December 31, 2014
		Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Electricity (gigawatt-hours)(a)	25,370			—			—		—		—			19,141			—
	Natural gas (millions of decatherms)	676			35			328		116		212			313			—
		December 31, 2013
		Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Electricity (gigawatt-hours)(a)	71,466			1,205			925		925		—			69,362			203
	Natural gas (millions of decatherms)	636			—			363		141		222			274			—
	(a)	Amounts at Duke Energy Ohio include intercompany positions that eliminate at Duke Energy.
Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Designated as Hedging Instruments
	Commodity contracts
	Current liabilities: other	$	—			$	—		$	—		$	1
	Interest rate contracts
	Investments and other assets: other	10				—			27			—
	Current liabilities: other	—				13			—			18
	Deferred credits and other liabilities: other	—				29			—			4
	Total Derivatives Designated as Hedging Instruments	$	10			$	42		$	27		$	23
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Current assets: other	$	18			$	—		$	201		$	158
	Current assets: assets held for sale	15				—			—			—
	Investments and other assets: other	3				—			215			131
	Investments and other assets: assets held for sale	15				—			—			—
	Current liabilities: other	1				307			13			153
	Current liabilities: assets held for sale	174				253			—			—
	Deferred credits and other liabilities: other	2				91			5			166
	Deferred credits and other liabilities: assets held for sale	111				208			—			—
	Interest rate contracts
	Current assets: other	2				—			—			—
	Current liabilities: other	—				1			—			1
	Deferred credits and other liabilities: other	—				7			—			4
	Total Derivatives Not Designated as Hedging Instruments	341				867			434			613
	Total Derivatives	$	351			$	909		$	461		$	636
Offsetting Assets	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
		Derivative Assets
		31-Dec-14							31-Dec-13
	(in millions)	Current(a)				Non-Current(b)			Current(e)			Non-Current(f)
	Gross amounts recognized	$	210			$	136		$	214		$	233
	Gross amounts offset	(153		)		(88		)	(179		)	(138		)
	Net amount subject to master netting	57				48			35			95
	Amounts not subject to master netting	—				5			—			14
	Net amounts recognized on the Consolidated Balance Sheet	$	57			$	53		$	35		$	109
Offsetting Liabilities
		Derivative Liabilities
		31-Dec-14							31-Dec-13
	(in millions)	Current(c)				Non-Current(d)			Current(g)			Non-Current(h)
	Gross amounts recognized	$	573			$	319		$	322		$	299
	Gross amounts offset	(213		)		(173		)	(192		)	(155		)
	Net amounts subject to master netting	360				146			130			144
	Amounts not subject to master netting	1				16			4			11
	Net amounts recognized on the Consolidated Balance Sheet	$	361			$	162		$	134		$	155
	(a)    Included in Other and Assets Held for Sale within Current Assets on the Consolidated Balance Sheet.
	(b)	Included in Other and Assets held for Sale within Investments and Other Assets on the Consolidated Balance Sheet.
	(c)	Included in Other and Liabilities Associated with Assets Held for Sale within Current Liabilities on the Consolidated Balance Sheet.
	(d)	Included in Other and Liabilities Associated with Assets Held for Sale within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
	(e)	Included in Other within Current Assets on the Consolidated Balance Sheet.
	(f)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
	(g)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
	(h)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
Cash Flow Hedges-Location And Amount Of Pre-Tax (Losses) Recognized In Comprehensive Income	The following table shows the gains and losses recognized on cash flow hedges and the line items on the Consolidated Statements of Operations where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Pretax Gains (Losses) Recorded in AOCI
	Interest rate contracts	$	(39	)		$	79		$	(23	)
	Commodity contracts	—				1			1
	Total Pretax Gains (Losses) Recorded in AOCI	$	(39	)		$	80		$	(22	)
	Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
	Interest rate contracts
	Interest expense	(7		)		(2		)	2
Undesignated Contracts - Location And Amount Of Pre-Tax Gains And (Losses) Recognized In Income Or As Regulatory Assets Or Liabilities	The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Recognized in Earnings
	Commodity contracts
	Revenue: Regulated electric	$	—			$	11		$	(23	)
	Other income and expenses	—				—			(2		)
	Fuel used in electric generation and purchased power-regulated	(44		)		(200		)	(194		)
	Income (Loss) From Discontinued Operations	(729		)		(57		)	40
	Interest rate contracts
	Interest expense	(6		)		(18		)	(8		)
	Total Pretax (Losses) Gains Recognized in Earnings	$	(779	)		$	(264	)	$	(187	)
	Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
	Commodity contracts
	Regulatory assets	$	(268	)		$	10		$	(2	)
	Regulatory liabilities	14				15			36
	Interest rate contracts
	Regulatory assets	—				55			10
	Regulatory liabilities	2				—			—
	Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(252	)		$	80		$	44
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features	The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk related payment provisions.
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas			Progress Energy			Duke Energy Progress				Duke Energy Florida			Duke Energy Ohio
	Aggregate fair value amounts of derivative instruments in a net liability position	$	845			$	19		$	370		$	131			$	239		$	456
	Fair value of collateral already posted	209				—			23			—				23			186
	Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	407				19			347			131				216			41
		December 31, 2013
	(in millions)	Duke Energy				Progress Energy			Duke Energy Progress			Duke Energy Florida				Duke Energy Ohio
	Aggregate fair value amounts of derivative instruments in a net liability position	$	525			$	168		$	60		$	108			$	355
	Fair value of collateral already posted	135				10			—			10				125
	Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	205				158			60			98				47
Schedule Of Cash Collateral Under Master Netting Arrangements	The Duke Energy Registrants have elected to offset cash collateral and fair values of derivatives. For amounts to be netted, the derivative must be executed with the same counterparty under the same master netting agreement. Amounts disclosed below represent the receivables related to the right to reclaim cash collateral and payables related to the obligation to return cash collateral under master netting arrangements.
		December 31,
		2014							2013
	(in millions)	Receivables				Payables			Receivables			Payables
	Duke Energy
	Amounts offset against net derivative positions	$	145			$	—		$	30		$	—
	Amounts not offset against net derivative positions	64				—			122			—
	Progress Energy
	Amounts offset against net derivative positions	23				—			10			—
	Duke Energy Florida
	Amounts offset against net derivative positions	23				—			10			—
	Duke Energy Ohio
	Amounts offset against net derivative positions	122				—			19			—
	Amounts not offset against net derivative positions	64				—			115			—
	Duke Energy Indiana
	Amounts offset against net derivative positions	—				—			—			1
	Amounts not offset against net derivative positions	—				—			1			—
Duke Energy Carolinas [Member]
Derivative [Line Items]
Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Current liabilities: other	$	—			$	14		$	—		$	1
	Deferred credits and other liabilities: other	—				5			—			1
	Total Derivatives Not Designated as Hedging Instruments	—				19			—			2
	Total Derivatives	$	—			$	19		$	—		$	2
Offsetting Assets	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
		Derivative Assets
		31-Dec-14							31-Dec-13
	(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
	Gross amounts recognized	$	—			$	—		$	—		$	—
	Gross amounts offset	—				—			—			—
	Net amount subject to master netting	—				—			—			—
	Amounts not subject to master netting	—				—			—			—
	Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	—		$	—
Offsetting Liabilities
		Derivative Liabilities
		31-Dec-14							31-Dec-13
	(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
	Gross amounts recognized	$	14			$	5		$	—		$	—
	Gross amounts offset	—				—			—			—
	Net amount subject to master netting	14				5			—			—
	Amounts not subject to master netting	—				—			1			1
	Net amounts recognized on the Consolidated Balance Sheet	$	14			$	5		$	1		$	1
	(a)	Included in Other within Current Assets on the Consolidated Balance Sheet.
	(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
	(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
	(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
Cash Flow Hedges-Location And Amount Of Pre-Tax (Losses) Recognized In Comprehensive Income	The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
	Interest rate contracts
	Interest expense	$	(3	)		$	(3	)	$	(3	)
Undesignated Contracts - Location And Amount Of Pre-Tax Gains And (Losses) Recognized In Income Or As Regulatory Assets Or Liabilities	The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts not included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Recognized in Earnings
	Commodity contracts
	Revenue: Regulated electric	$	—			$	(12	)	$	(12	)
	Total Pretax (Losses) Gains Recognized in Earnings	—				(12		)	(12		)
	Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
	Commodity contracts
	Regulatory assets	$	(19	)		$	—		$	—
Progress Energy [Member]
Derivative [Line Items]
Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Designated as Hedging Instruments
	Commodity contracts
	Current liabilities: other	$	—			$	1		$	—		$	1
	Deferred credits and other liabilities: other	—				—			—			4
	Total Derivatives Designated as Hedging Instruments	$	—			$	1		$	—		$	5
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Current assets: other	$	—			$	—		$	3		$	2
	Investments and other assets: other	—				—			2			1
	Current liabilities: other	—				288			11			105
	Deferred credits and other liabilities: other	—				80			4			91
	Interest rate contracts
	Current assets: other	2				—			—			—
	Deferred credits and other liabilities: other	—				2			—			—
	Total Derivatives Not Designated as Hedging Instruments	2				370			20			199
	Total Derivatives	$	2			$	371		$	20		$	204
Offsetting Assets	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
		Derivative Assets
		31-Dec-14							31-Dec-13
	(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
	Gross amounts recognized	$	2			$	—		$	15		$	5
	Gross amounts offset	(2		)		—			(13		)	(4		)
	Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	2		$	1
Offsetting Liabilities
		Derivative Liabilities
		31-Dec-14							31-Dec-13
	(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
	Gross amounts recognized	$	289			$	82		$	107		$	93
	Gross amounts offset	(17		)		(8		)	(17		)	(10		)
	Net amounts subject to master netting	272				74			90			83
	Amounts not subject to master netting	—				—			—			4
	Net amounts recognized on the Consolidated Balance Sheet	$	272			$	74		$	90		$	87
	(a)    Included in Other within Current Assets on the Consolidated Balance Sheet.
	(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
	(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
	(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
Cash Flow Hedges-Location And Amount Of Pre-Tax (Losses) Recognized In Comprehensive Income	The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income or Consolidated Balance Sheet where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Pretax Gains (Losses) Recorded in AOCI
	Commodity contracts	$	—			$	1		$	1
	Interest rate contracts	—				—			(11		)
	Total Pretax Gains (Losses) Recorded in AOCI	$	—			$	1		$	(10	)
	Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
	Interest rate contracts
	Interest expense	(13		)		—			(14		)
	Location of Pretax Gains and (Losses) Reclassified from AOCI to Regulatory Assets or Liabilities(a)
	Interest rate contracts
	Regulatory assets	—				$	—		(159		)
	(a)    Effective with the merger, Duke Energy Progress and Duke Energy Florida no longer designates interest rate derivatives for
	regulated operations as cash flow hedges. As a result, the pretax losses on derivatives as of the date of the merger were reclassified from AOCI to regulatory assets.
Undesignated Contracts - Location And Amount Of Pre-Tax Gains And (Losses) Recognized In Income Or As Regulatory Assets Or Liabilities	The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Recognized in Earnings
	Commodity contracts
	Operating revenues	$	—			$	11		$	(11	)
	Fuel used in electric generation and purchased power	(44		)		(200		)	(454		)
	Other income and expenses, net	—				—			7
	Interest rate contracts
	Interest expense	(4		)		(17		)	(8		)
	Total Pretax (Losses) Gains Recognized in Earnings	$	(48	)		$	(206	)	$	(466	)
	Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
	Commodity contracts
	Regulatory assets	$	(233	)		$	10		$	(171	)
	Regulatory liabilities	2				—			—
	Interest rate contracts
	Regulatory assets	2				18			6
	Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(229	)		$	28		$	(165	)
Duke Energy Progress [Member]
Derivative [Line Items]
Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown. Substantially all derivatives not designated as hedging instruments receive regulatory accounting treatment.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Designated as Hedging Instruments
	Commodity contracts
	Current liabilities: other	$	—			$	1		$	—		$	1
	Total Derivatives Designated as Hedging Instruments	—				1			—			1
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Investments and other assets: other	$	—			$	—		$	2		$	1
	Current liabilities: other	—				108			2			40
	Deferred credits and other liabilities: other	—				23			2			29
	Total Derivatives Not Designated as Hedging Instruments	—				131			6			70
	Total Derivatives	$	—			$	132		$	6		$	71
Offsetting Assets	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
		Derivative Assets
		31-Dec-14							31-Dec-13
	(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
	Gross amounts recognized	$	—			$	—		$	3		$	3
	Gross amounts offset	—				—			(3		)	(3		)
	Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	—		$	—
Offsetting Liabilities
		Derivative Liabilities
		31-Dec-14							31-Dec-13
	(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
	Gross amounts recognized	$	109			$	23		$	41		$	30
	Gross amounts offset	—				—			(3		)	(3		)
	Net amounts recognized on the Consolidated Balance Sheet	$	109			$	23		$	38		$	27
	(a)    Included in Other within Current Assets on the Consolidated Balance Sheet.
	(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
	(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
	(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
Cash Flow Hedges-Location And Amount Of Pre-Tax (Losses) Recognized In Comprehensive Income	The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income or Consolidated Balance Sheets in which such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Pretax Gains (Losses) Recorded in AOCI
	Interest rate contracts	$	—			$	—		$	(7	)
	Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
	Interest rate contracts
	Interest expense	—				—			(5		)
	Location of Pretax Gains and (Losses) Reclassified from AOCI to Regulatory Assets or Liabilities(a)
	Interest rate contracts
	Regulatory assets	—				$	—		(117		)
	(a)	Effective with the merger, Duke Energy Progress no longer designates interest rate derivatives for regulated operations as cash flow hedges. As a result, the pretax losses on derivatives as of the date of the merger were reclassified from AOCI to Regulatory assets.
Undesignated Contracts - Location And Amount Of Pre-Tax Gains And (Losses) Recognized In Income Or As Regulatory Assets Or Liabilities	The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Recognized in Earnings
	Commodity contracts
	Operating revenues	$	—			$	11		$	(11	)
	Fuel used in electric generation and purchased power	(15		)		(71		)	(115		)
	Interest rate contracts
	Interest expense	—				(13		)	(6		)
	Total Pretax (Losses) Gains Recognized in Earnings	$	(15	)		$	(73	)	$	(132	)
	Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
	Commodity contracts
	Regulatory assets	$	(82	)		$	(6	)	$	(55	)
	Interest rate contracts
	Regulatory assets	—				13			6
	Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(82	)		$	7		$	(49	)
Duke Energy Florida [Member]
Derivative [Line Items]
Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Current assets: other	$	—			$	—		$	3		$	2
	Current liabilities: other	—				180			9			64
	Deferred credits and other liabilities: other	—				57			2			63
	Interest rate contracts
	Current assets: other	2				—			—			—
	Deferred credits and other liabilities: other	—				2			—			—
	Total Derivatives Not Designated as Hedging Instruments	2				239			14			129
	Total Derivatives	$	2			$	239		$	14		$	129
Offsetting Assets	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
		Derivative Assets
		31-Dec-14							31-Dec-13
	(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
	Gross amounts recognized	$	2			$	—		$	12		$	2
	Gross amounts offset	(2		)		—			(10		)	(2		)
	Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	2		$	—
Offsetting Liabilities
		Derivative Liabilities
		31-Dec-14							31-Dec-13
	(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
	Gross amounts recognized	$	180			$	59		$	66		$	63
	Gross amounts offset	(17		)		(8		)	(15		)	(7		)
	Net amounts recognized on the Consolidated Balance Sheet	$	163			$	51		$	51		$	56
	(a)	Included in Other within Current Assets on the Consolidated Balance Sheet.
	(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
	(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
	(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
Cash Flow Hedges-Location And Amount Of Pre-Tax (Losses) Recognized In Comprehensive Income	The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income or Consolidated Balance Sheets in which such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Pretax Gains (Losses) Recorded in AOCI
	Commodity contracts	$	—			$	1		$	1
	Interest rate contracts	—				—			(2		)
	Total Pretax Gains (Losses) Recorded in AOCI	$	—			$	1		$	(1	)
	Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
	Interest rate contracts
	Interest expense	(2		)		—			(2		)
	Location of Pretax Gains and (Losses) Reclassified from AOCI to Regulatory Assets(a)
	Interest rate contracts
	Regulatory assets	—				$	—		(42		)
	(a)	Effective with the merger, Duke Energy Florida no longer designates interest rate derivatives for regulated operations as cash flow hedges. As a result, the pretax losses on derivatives as of the date of the merger were reclassified from AOCI to Regulatory assets.
Undesignated Contracts - Location And Amount Of Pre-Tax Gains And (Losses) Recognized In Income Or As Regulatory Assets Or Liabilities	The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Recognized in Earnings
	Commodity contracts
	Fuel used in electric generation and purchased power	$	(29	)		$	(129	)	$	(339	)
	Interest rate contracts
	Interest expense	(4		)		(5		)	(2		)
	Total Pretax (Losses) Gains Recognized in Earnings	$	(33	)		$	(134	)	$	(341	)
	Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
	Commodity contracts
	Regulatory assets	$	(151	)		$	16		$	(116	)
	Interest rate contracts
	Regulatory assets	2				5			—
	Regulatory liabilities	2				—			—
	Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(147	)		$	21		$	(116	)
Duke Energy Ohio [Member]
Derivative [Line Items]
Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Current assets: other	$	1			$	—		$	186		$	163
	Current assets: assets held for sale	28				4			—			—
	Investments and other assets: other	—				—			202			130
	Investments and other assets: assets held for sale	26				4			—			—
	Current liabilities: other	—				—			1			36
	Current liabilities: assets held for sale	175				252			—			—
	Deferred credits and other liabilities: other	—				—			2			56
	Deferred credits and other liabilities: assets held for sale	111				207			—			—
	Interest rate contracts
	Current liabilities: other	—				1			—			1
	Deferred credits and other liabilities: other	—				5			—			4
	Total Derivatives Not Designated as Hedging Instruments	341				473			391			390
	Total Derivatives	$	341			$	473		$	391		$	390
Offsetting Assets	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
		Derivative Assets
		31-Dec-14							31-Dec-13
	(in millions)	Current(a)				Non-Current(b)			Current(e)			Non-Current(f)
	Gross amounts recognized	$	204			$	137		$	186		$	205
	Gross amounts offset	(179		)		(114		)	(165		)	(132		)
	Net amounts recognized on the Consolidated Balance Sheet	$	25			$	23		$	21		$	73
Offsetting Liabilities
		Derivative Liabilities
		31-Dec-14							31-Dec-13
	(in millions)	Current(c)				Non-Current(d)			Current(g)			Non-Current(h)
	Gross amounts recognized	$	257			$	216		$	199		$	186
	Gross amounts offset	(222		)		(193		)	(173		)	(143		)
	Net amounts subject to master netting	35				23			26			43
	Amounts not subject to master netting	—				—			1			4
	Net amounts recognized on the Consolidated Balance Sheet	$	35			$	23		$	27		$	47
	(a)    Included in Other and Assets Held for Sale within Current Assets on the Consolidated Balance Sheet.
	(b)	Included in Other and Assets held for Sale within Investments and Other Assets on the Consolidated Balance Sheet.
	(c)	Included in Other and Liabilities Associated with Assets Held for Sale within Current Liabilities on the Consolidated Balance Sheet.
	(d)	Included in Other and Liabilities Associated with Assets Held for Sale within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
	(e)	Included in Other within Current Assets on the Consolidated Balance Sheet.
	(f)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
	(g)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
	(h)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
Undesignated Contracts - Location And Amount Of Pre-Tax Gains And (Losses) Recognized In Income Or As Regulatory Assets Or Liabilities	The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Statements of Operations and Comprehensive Income or the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Recognized in Earnings
	Commodity contracts
	Income (Loss) from discontinued operations	(758		)		(56		)	78
	Interest rate contracts
	Interest expense	(1		)		(1		)	(1		)
	Total Pretax (Losses) Gains Recognized in Earnings	$	(759	)		$	(57	)	$	77
	Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
	Commodity contracts
	Regulatory assets	$	1			$	—		$	2
	Regulatory liabilities	5				—			(1		)
	Interest rate contracts
	Regulatory assets	(2		)		4			—
	Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	4			$	4		$	1
Duke Energy Indiana [Member]
Derivative [Line Items]
Location And Fair Value Amounts Of Derivatives Reflected In The Condensed Consolidated Balance Sheets	The following table shows the fair value of derivatives and the line items in the Consolidated Balance Sheets where they are reported. Although derivatives subject to master netting arrangements are netted on the Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.
		December 31,
		2014							2013
	(in millions)	Asset				Liability			Asset			Liability
	Derivatives Not Designated as Hedging Instruments
	Commodity contracts
	Current Assets: Other	$	14			$	—		$	12		$	—
	Total Derivatives Not Designated as Hedging Instruments	14				—			12			—
	Total Derivatives	$	14			$	—		$	12		$	—
Offsetting Assets	The tables below show the balance sheet location of derivative contracts subject to enforceable master netting agreements and include collateral posted to offset the net position. This disclosure is intended to enable users to evaluate the effect of netting arrangements on financial position. The amounts shown were calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.
		Derivative Assets
		31-Dec-14							31-Dec-13
	(in millions)	Current(a)				Non-Current(b)			Current(a)			Non-Current(b)
	Gross amounts recognized	$	14			$	—		$	12		$	—
	Gross amounts offset	—				—			(1		)	—
	Net amounts recognized on the Consolidated Balance Sheet	$	14			$	—		$	11		$	—
Offsetting Liabilities
		Derivative Liabilities
		31-Dec-14							31-Dec-13
	(in millions)	Current(c)				Non-Current(d)			Current(c)			Non-Current(d)
	Gross amounts recognized	$	—			$	—		$	—		$	—
	Gross amounts offset	—				—			—			—
	Net amount subject to master netting	—				—			—			—
	Amounts not subject to master netting	—				—			—			—
	Net amounts recognized on the Consolidated Balance Sheet	$	—			$	—		$	—		$	—
	(a)	Included in Other within Current Assets on the Consolidated Balance Sheet.
	(b)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheet.
	(c)	Included in Other within Current Liabilities on the Consolidated Balance Sheet.
	(d)	Included in Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.
Cash Flow Hedges-Location And Amount Of Pre-Tax (Losses) Recognized In Comprehensive Income	The following table shows the gains and losses during the year recognized on cash flow hedges and the line items on the Consolidated Statements of Operations and Comprehensive Income where such gains and losses are included when reclassified from AOCI. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Reclassified from AOCI into Earnings
	Interest rate contracts
	Interest expense	$	—			$	3		$	3
Undesignated Contracts - Location And Amount Of Pre-Tax Gains And (Losses) Recognized In Income Or As Regulatory Assets Or Liabilities	The following table shows the gains and losses during the year recognized on undesignated derivatives and the line items on the Consolidated Balance Sheets where the pretax gains and losses were reported. Amounts included in Regulatory Assets or Liabilities for commodity contracts are reclassified to earnings to match recovery through the fuel clause. Amounts included in Regulatory Assets or Liabilities for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt.
		Years Ended December 31,
	(in millions)	2014				2013			2012
	Location of Pretax Gains and (Losses) Recognized in Earnings
	Commodity contracts
	Revenue: Regulated electric	$	—			$	1		$	—
	Location of Pretax Gains and (Losses) Recognized as Regulatory Assets or Liabilities
	Commodity contracts
	Regulatory assets	$	(16	)		$	—		$	2
	Regulatory liabilities	9				16			35
	Interest rate contracts
	Regulatory assets	—				34			4
	Regulatory liabilities	—				—			—
	Total Pretax Gains (Losses) Recognized as Regulatory Assets or Liabilities	$	(7	)		$	50		$	41

Investments_in_Debt_and_Equity1

Investments in Debt and Equity Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Investments	The following table presents the estimated fair value of investments in available-for-sale securities.
		31-Dec-14						31-Dec-13
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	NDTF
	Cash and cash equivalents	$	—	$	—	$	136	$	—	$	—	$	110
	Equity securities	1,926		29		3,650		1,813		10		3,579
	Corporate debt securities	14		2		454		8		6		400
	Municipal bonds	5		—		184		2		6		160
	U.S. government bonds	19		2		978		7		12		730
	Other debt securities	1		2		147		22		2		154
	Total NDTF	1,965		35		5,549		1,852		36		5,133
	Other Investments
	Cash and cash equivalents	—		—		15		—		—		21
	Equity securities	34		—		96		29		—		91
	Corporate debt securities	1		1		58		1		1		99
	Municipal bonds	3		1		76		2		2		79
	U.S. government bonds	—		—		27		—		—		17
	Other debt securities	1		1		80		—		8		111
	Total Other Investments(a)	39		3		352		32		11		418
	Total Investments	$	2,004	$	38	$	5,901	$	1,884	$	47	$	5,551
	(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
Schedule of Maturity Dates for Debt Securities	The table below summarizes the maturity date for debt securities.
	(in millions)	December 31, 2014
	Due in one year or less	178
	Due after one through five years	571
	Due after five through 10 years	464
	Due after 10 years	791
	Total	2,004
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Realized gains	$	271	$	209	$	117
	Realized losses	105		65		19
Duke Energy Carolinas [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Investments	The following table presents the estimated fair value of investments in available-for-sale securities.
		December 31, 2014						December 31, 2013
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	NDTF
	Cash and cash equivalents	$	—	$	—	$	51	$	—	$	—	$	42
	Equity securities	1,102		17		2,162		974		6		1,964
	Corporate debt securities	8		2		316		5		5		274
	Municipal bonds	1		—		62		—		2		54
	U.S. government bonds	7		1		308		3		7		354
	Other debt securities	1		2		133		22		2		146
	Total NDTF	1,119		22		3,032		1,004		22		2,834
	Other Investments
	Other debt securities	—		1		3		—		1		3
	Total Other Investments(a)	—		1		3		—		1		3
	Total Investments	$	1,119	$	23	$	3,035	$	1,004	$	23	$	2,837
	(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
Schedule of Maturity Dates for Debt Securities	The table below summarizes the maturity date for debt securities.
	(in millions)	December 31, 2014
	Due in one year or less	$	1
	Due after one through five years	155
	Due after five through 10 years	257
	Due after 10 years	409
	Total	$	822
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Realized gains	$	109	$	115	$	89
	Realized losses	93		12		6
Progress Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Investments	The following table presents the estimated fair value of investments in available-for-sale securities.
		31-Dec-14						31-Dec-13
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	NDTF
	Cash and cash equivalents	$	—	$	—	$	85	$	—	$	—	$	68
	Equity securities	824		12		1,488		839		4		1,615
	Corporate debt securities	6		—		138		3		1		126
	Municipal bonds	4		—		122		2		4		106
	U.S. government bonds	12		1		670		4		5		376
	Other debt securities	—		—		14		—		—		8
	Total NDTF	846		13		2,517		848		14		2,299
	Other Investments
	Cash and cash equivalents	—		—		15		—		—		20
	Municipal bonds	3		—		43		1		—		39
	Total Other Investments(a)	3		—		58		1		—		59
	Total Investments	$	849	$	13	$	2,575	$	849	$	14	$	2,358
	(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
Schedule of Maturity Dates for Debt Securities	The table below summarizes the maturity date for debt securities.
	(in millions)	December 31, 2014
	Due in one year or less	$	161
	Due after one through five years	350
	Due after five through 10 years	157
	Due after 10 years	319
	Total	$	987
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Realized gains	$	157	$	90	$	34
	Realized losses	11		46		18
Duke Energy Progress [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Investments	The following table presents the estimated fair value of investments in available-for-sale securities.
		December 31, 2014						December 31, 2013
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	NDTF
	Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	48
	Equity securities	612		10		1,171		535		3		1,069
	Corporate debt securities	5		—		97		3		1		80
	Municipal bonds	4		—		120		2		4		104
	U.S. government bonds	9		1		265		4		3		232
	Other debt securities	—		—		8		—		—		5
	Total NDTF	630		11		1,711		544		11		1,538
	Other Investments
	Cash and cash equivalents	—		—		—		—		—		2
	Total Other Investments(a)	—		—		—		—		—		2
	Total Investments	$	630	$	11	$	1,711	$	544	$	11	$	1,540
	(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
Schedule of Maturity Dates for Debt Securities	The table below summarizes the maturity date for debt securities.
	(in millions)	December 31, 2014
	Due in one year or less	$	14
	Due after one through five years	140
	Due after five through 10 years	109
	Due after 10 years	227
	Total	$	490
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Realized gains	$	19	$	58	$	21
	Realized losses	5		26		8
Duke Energy Florida [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Investments	The following table presents the estimated fair value of investments in available-for-sale securities.
		December 31, 2014						December 31, 2013
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	NDTF
	Cash and cash equivalents	$	—	$	—	$	35	$	—	$	—	$	20
	Equity securities	212		2		317		304		1		546
	Corporate debt securities	1		—		41		—		—		46
	Municipal bonds	—		—		2		—		—		2
	U.S. government bonds	3		—		405		—		2		144
	Other debt securities	—		—		6		—		—		3
	Total NDTF	216		2		806		304		3		761
	Other Investments
	Cash and cash equivalents	—		—		1		—		—		3
	Municipal bonds	3		—		43		1		—		39
	Total Other Investments(a)	3		—		44		1		—		42
	Total Investments	$	219	$	2	$	850	$	305	$	3	$	803
	(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
Schedule of Maturity Dates for Debt Securities	The table below summarizes the maturity date for debt securities.
	(in millions)	December 31, 2014
	Due in one year or less	$	147
	Due after one through five years	210
	Due after five through 10 years	48
	Due after 10 years	92
	Total	$	497
Schedule of Realized Gain (Loss)	Realized gains and losses, which were determined on a specific identification basis, from sales of available-for-sale securities were as follows.
		Years Ended December 31,
	(in millions)	2014		2013		2012
	Realized gains	$	138	$	32	$	13
	Realized losses	5		20		9
Duke Energy Indiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Investments	The following table presents the estimated fair value of investments in available-for-sale securities.
		December 31, 2014						December 31, 2013
	(in millions)	Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Estimated Fair Value
	Other Investments
	Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
	Equity securities	28		—		71		24		—		65
	Municipal bonds	—		1		30		—		1		28
	Total Other Investments(a)	28		1		101		24		1		94
	Total Investments	$	28	$	1	$	101	$	24	$	1	$	94
	(a)	These amounts are recorded in Other within Investments and Other Assets on the Consolidated Balance Sheets.
Schedule of Maturity Dates for Debt Securities	The table below summarizes the maturity date for debt securities.
	(in millions)	December 31, 2014
	Due in one year or less	$	1
	Due after one through five years	17
	Due after five through 10 years	8
	Due after 10 years	4
	Total	$	30

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	3,650			$	3,493			$	6		$	151
	Nuclear decommissioning trust fund debt securities	1,899				648				1,251			—
	Other trading and available-for-sale equity securities	96				96				—			—
	Other trading and available-for-sale debt securities	263				41				217			5
	Derivative assets	110				49				24			37
	Total assets	6,018				4,327				1,498			193
	Derivative liabilities	(668		)		(162		)		(468		)	(38		)
	Net assets	$	5,350			$	4,165			$	1,030		$	155
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	3,579			$	3,495			$	57		$	27
	Nuclear decommissioning trust fund debt securities	1,553				402				1,100			51
	Other trading and available-for-sale equity securities	102				91				11			—
	Other trading and available-for-sale debt securities	333				36				277			20
	Derivative assets	145				33				70			42
	Total assets	5,712				4,057				1,515			140
	Derivative liabilities	(321		)		11				(303		)	(29		)
	Net assets	$	5,391			$	4,068			$	1,212		$	111
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following tables provide reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Amounts included in earnings for derivatives are primarily included in Operating Revenues.
		December 31, 2014
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	98			$	13			$	111
	Total pretax realized or unrealized gains (losses) included in earnings	—				(7		)		(7		)
	Purchases, sales, issuances and settlements:
	Purchases	34				50				84
	Sales	(58		)		—				(58		)
	Settlements	—				(54		)		(54		)
	Transfers into Level 3	68				6				74
	Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	14				(9		)		5
	Balance at end of period	$	156			$	(1	)		$	155
	Pretax amounts included in the Consolidated Statements of Comprehensive Income related to Level 3 measurements outstanding	$	—			$	(14	)		$	(14	)
		December 31, 2013
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	98			$	(85	)		$	13
	Total pretax realized or unrealized gains (losses) included in earnings	—				(42		)		(42		)
	Purchases, sales, issuances and settlements:
	Purchases	9				21				30
	Sales	(6		)		—				(6		)
	Issuances	—				11				11
	Settlements	(9		)		25				16
	Transfers into Level 3	—				86				86
	Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	6				(3		)		3
	Balance at end of period	$	98			$	13			$	111
		December 31, 2012
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	124			$	(39	)		$	85
	Amounts acquired in Progress Energy Merger	—				(30		)		(30		)
	Total pretax realized or unrealized gains (losses) included in earnings	—				8				8
	Total pretax gains included in other comprehensive income	13				—				13
	Purchases, sales, issuances and settlements:
	Purchases	14				22				36
	Sales	(2		)		—				(2		)
	Issuances	—				(15		)		(15		)
	Settlements	(55		)		(32		)		(87		)
	Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	4				1				5
	Balance at end of period	$	98			$	(85	)		$	13
Schedule of Long-term debt, including current	The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements.
		December 31, 2014								December 31, 2013
	(in millions)	Book Value				Fair Value				Book Value			Fair Value
	Duke Energy	$	40,020			$	44,566			$	40,256		$	42,592
	Duke Energy Carolinas	8,391				9,626				8,436			9,123
	Progress Energy	14,754				16,951				14,115			15,234
	Duke Energy Progress	6,201				6,696				5,235			5,323
	Duke Energy Florida	4,860				5,767				4,886			5,408
	Duke Energy Ohio	1,766				1,970				2,188			2,237
	Duke Energy Indiana	3,791				4,456				3,796			4,171
Quantitative Information Table - Level 3	The following table includes quantitative information about the Duke Energy Registrants' derivatives classified as Level 3.
		December 31, 2014
	Investment Type	Fair Value			Valuation Technique	Unobservable Input	Range
		(in millions)
	Duke Energy
	Natural gas contracts	$	(5	)	Discounted cash flow	Forward natural gas curves - price per Million British Thermal Unit (MMBtu)	$	2.12		-	4.35
	Financial transmission rights (FTRs)	14			RTO auction pricing	FTR price - per Megawatt-Hour (MWh)	(1.92		)	-	9.86
	Electricity contracts	(1		)	Discounted cash flow	Forward electricity curves - price per MWh	25.16			-	51.75
	Commodity capacity option contracts	2			Discounted cash flow	Forward capacity option curves  - price per MW day	21			-	109
	Reserves	(11		)		Bid-ask spreads, implied volatility, probability of default
	Total Level 3 derivatives	$	(1	)
	Duke Energy Ohio
	Electricity contracts	$	(6	)	Discounted cash flow	Forward electricity curves - price per MWh	$	25.25		-	51.75
	Natural gas contracts	(5		)	Discounted cash flow	Forward natural gas curves - price per MMBtu	2.12			-	4.35
	Reserves	(7		)		Bid-ask spreads, implied volatility, probability of default
	Total Level 3 derivatives	$	(18	)
	Duke Energy Indiana
	FTRs	$	14		RTO auction pricing	FTR price - per MWh	$	(1.92	)	-	9.86
		December 31, 2013
	Investment Type	Fair Value			Valuation Technique	Unobservable Input	Range
		(in millions)
	Duke Energy
	Natural gas contracts	$	(2	)	Discounted cash flow	Forward natural gas curves - price per MMBtu	$	3.07		-	5.37
	FERC mitigation power sale agreements	(2		)	Discounted cash flow	Forward electricity curves - price per MWh	25.79			-	52.38
	FTRs	12			RTO auction pricing	FTR price - per MWh	(0.30		)	-	13.8
	Electricity contracts	23			Discounted cash flow	Forward electricity curves - price per MWh	20.77			-	58.9
	Commodity capacity option contracts	4			Discounted cash flow	Forward capacity option curves  - price per MW day	30.4			-	165.1
	Reserves	(22		)		Bid-ask spreads, implied volatility, probability of default
	Total Level 3 derivatives	$	13
	Duke Energy Carolinas
	FERC mitigation power sale agreements	$	(2	)	Discounted cash flow	Forward electricity curves - price per MWh	$	25.79		-	52.38
	Duke Energy Ohio
	Electricity contracts	$	18		Discounted cash flow	Forward electricity curves - price per MWh	$	20.77		-	58.9
	Natural gas contracts	(2		)	Discounted cash flow	Forward natural gas curves - price per MMBtu	3.07			-	5.37
	Reserves	(20		)		Bid-ask spreads, implied volatility, probability of default
	Total Level 3 derivatives	$	(4	)
	Duke Energy Indiana
	FTRs	$	12		RTO auction pricing	FTR price - per MWh	$	(0.30	)	-	13.8
Duke Energy Carolinas [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	2,162			$	2,005			$	6		$	151
	Nuclear decommissioning trust fund debt securities	870				138				732			—
	Other trading and available-for-sale debt securities	3				—				—			3
	Total assets	3,035				2,143				738			154
	Derivative liabilities	(19		)		—				(19		)	—
	Net assets	$	3,016			$	2,143			$	719		$	154
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	1,964			$	1,879			$	58		$	27
	Nuclear decommissioning trust fund debt securities	870				168				651			51
	Other trading and available-for-sale debt securities	3				—				—			3
	Total assets	2,837				2,047				709			81
	Derivative liabilities	(2		)		—				—			(2		)
	Net assets	$	2,835			$	2,047			$	709		$	79
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following tables provide a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
		December 31, 2014
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	81			$	(2	)		$	79
	Purchases, sales, issuances and settlements:
	Purchases	34				—				34
	Sales	(43		)		—				(43		)
	Settlements	—				2				2
	Transfers into Level 3	68				—				68
	Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	14				—				14
	Balance at end of period	$	154			$	—			$	154
		December 31, 2013
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	72			$	(12	)		$	60
	Purchases, sales, issuances and settlements:
	Purchases	9				—				9
	Issuances	(6		)		—				(6		)
	Settlements	—				10				10
	Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	6				—				6
	Balance at end of period	$	81			$	(2	)		$	79
		December 31, 2012
	(in millions)	Investments				Derivatives (net)				Total
	Balance at beginning of period	$	65			$	—			$	65
	Total pretax gains included in other comprehensive income	2				—				2
	Purchases, sales, issuances and settlements:
	Purchases	14				—				14
	Sales	—				(14		)		(14		)
	Issuances	(2		)		—				(2		)
	Settlements	(11		)		2				(9		)
	Total gains included on the Consolidated Balance Sheet as regulatory assets or liabilities	4				—				4
	Balance at end of period	$	72			$	(12	)		$	60
Progress Energy [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis end on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	1,488			$	1,488			$	—		$	—
	Nuclear decommissioning trust fund debt securities	1,029				510				519			—
	Other trading and available-for-sale debt securities	58				15				43			—
	Derivative assets	4				—				4			—
	Total assets	2,579				2,013				566			—
	Derivative liabilities	(373		)		—				(373		)	—
	Net assets	$	2,206			$	2,013			$	193		$	—
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	1,615			$	1,615			$	—		$	—
	Nuclear decommissioning trust fund debt securities	677				233				444			—
	Other trading and available-for-sale debt securities	58				19				39			—
	Derivative assets	3				—				3			—
	Total assets	2,353				1,867				486			—
	Derivative liabilities	(187		)		—				(187		)	—
	Net assets	$	2,166			$	1,867			$	299		$	—
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
		Derivatives (net)
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Balance at beginning of period	$	—			$	(38	)		$	(24	)
	Total pretax realized or unrealized gains included in earnings	—				—				1
	Purchases, sales, issuances and settlements:
	Issuances	—				10				(16		)
	Settlements	—				—				4
	Transfers into Level 3	—				34				—
	Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	—				(6		)		(3		)
	Balance at end of period	$	—			$	—			$	(38	)
Duke Energy Progress [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	1,171			$	1,171			$	—		$	—
	Nuclear decommissioning trust fund debt securities and other	540				151				389			—
	Total assets	1,711				1,322				389			—
	Derivative liabilities	(132		)		—				(132		)	—
	Net assets	$	1,579			$	1,322			$	257		$	—
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	1,069			$	1,069			$	—		$	—
	Nuclear decommissioning trust fund debt securities and other	470				137				333			—
	Other trading and available-for-sale debt securities and other	3				3				—			—
	Derivative assets	1				—				1			—
	Total assets	1,543				1,209				334			—
	Derivative liabilities	(66		)		—				(66		)	—
	Net assets	$	1,477			$	1,209			$	268		$	—
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
		Derivatives (net)
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Balance at beginning of period	$	—			$	(38	)		$	(24	)
	Total pretax realized or unrealized gains included in earnings	—				—				1
	Purchases, sales, issuances and settlements:
	Issuances	—				10				(16		)
	Settlements	—				—				4
	Transfers into Level 3	—				34				—
	Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	—				(6		)		(3		)
	Balance at end of period	$	—			$	—			$	(38	)
Duke Energy Florida [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	317			$	317			$	—		$	—
	Nuclear decommissioning trust fund debt securities and other	489				359				130			—
	Other trading and available-for-sale debt securities and other	44				—				44			—
	Derivative assets	4				—				4			—
	Total assets	854				676				178			—
	Derivative liabilities	(241		)		—				(241		)	—
	Net assets (liabilities)	$	613			$	676			$	(63	)	$	—
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Nuclear decommissioning trust fund equity securities	$	546			$	546			$	—		$	—
	Nuclear decommissioning trust fund debt securities and other	214				96				118			—
	Other trading and available-for-sale debt securities and other	40				2				38			—
	Derivative assets	1				—				1			—
	Total assets	801				644				157			—
	Derivative liabilities	(116		)		—				(116		)	—
	Net assets	$	685			$	644			$	41		$	—
Duke Energy Ohio [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which are disclosed in Note 14.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Derivative assets	$	49			$	20			$	9		$	20
	Derivative liabilities	(181		)		(117		)		(26		)	(38		)
	Net assets (liabilities)	$	(132	)		$	(97	)		$	(17	)	$	(18	)
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Derivative assets	$	96			$	50			$	21		$	25
	Derivative liabilities	(95		)		(1		)		(65		)	(29		)
	Net assets (liabilities)	$	1			$	49			$	(44	)	$	(4	)
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
		Derivatives (net)
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Balance at beginning of period	$	(4	)		$	(6	)		$	(3	)
	Total pretax realized or unrealized gains included in earnings	(9		)		(42		)		(3		)
	Purchases, sales, issuances and settlements:
	Purchases	1				1				—
	Settlements	(13		)		—				1
	Transfers into Level 3	6				43				—
	Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	1				—				(1		)
	Balance at end of period	$	(18	)		$	(4	)		$	(6	)
Duke Energy Indiana [Member]
Fair Value Disclosures [Line Items]
Fair Value Measurement Amounts For Assets And Liabilities	The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Consolidated Balance Sheets. Derivative amounts in the table below exclude cash collateral, which is disclosed in Note 14. See Note 15 for additional information related to investments by major security type.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Available-for-sale equity securities	$	71			$	71			$	—		$	—
	Available-for-sale debt securities	30				—				30			—
	Derivative assets	14				—				—			14
	Net assets (liabilities)	$	115			$	71			$	30		$	14
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2			Level 3
	Available-for-sale equity securities	$	65			$	65			$	—		$	—
	Available-for-sale debt securities	29				—				29			—
	Derivative assets	12				—				—			12
	Net assets (liabilities)	$	106			$	65			$	29		$	12
Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs	The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.
		Derivatives (net)
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Balance at beginning of period	$	12			$	10			$	4
	Total pretax realized or unrealized gains included in earnings	3				8				36
	Purchases, sales, issuances and settlements:
	Purchases	49				20				—
	Issuances	—				—				22
	Settlements	(41		)		(30		)		(52		)
	Total losses included on the Consolidated Balance Sheet as regulatory assets or liabilities	(9		)		4				—
	Balance at end of period	$	14			$	12			$	10

Variable_Interest_Entities_Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2014
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Schedule Of Variable Interest Entities	The following tables summarize the impact of VIEs consolidated by Duke Energy and the Subsidiary Registrants on the Consolidated Balance Sheets.
		December 31, 2014
		Duke Energy
		Duke Energy Carolinas			Duke Energy Progress				Duke Energy Florida
	(in millions)	DERF			DEPR(c)				DEFR(c)			CRC			Renewables			Other			Total
	ASSETS
	Current Assets
	Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	$	647		$	436			$	305		$	547		$	20		$	18		$	1,973
	Other	—			—				—			—			68			6			74
	Investments and Other Assets
	Other	—			—				—			—			25			25			50
	Property, Plant and Equipment
	Property, plant and equipment, cost(a)	—			—				—			—			1,855			18			1,873
	Accumulated depreciation and amortization	—			—				—			—			(250		)	(5		)	(255		)
	Regulatory Assets and Deferred Debits
	Other	—			—				—			—			34			2			36
	Total assets	$	647		$	436			$	305		$	547		$	1,752		$	64		$	3,751
	LIABILITIES AND EQUITY
	Current Liabilities
	Accounts payable	—			—				—			—			3			—			3
	Taxes accrued	—			—				—			—			6			—			6
	Current maturities of long-term debt	—			—				—			—			68			16			84
	Other	—			—				—			—			16			5			21
	Long-Term Debt(b)	400			300				225			325			967			17			2,234
	Deferred Credits and Other Liabilities
	Deferred income taxes	—			—				—			—			283			—			283
	Asset retirement obligations	—			—				—			—			29			—			29
	Other	—			—				—			—			34			4			38
	Total liabilities	$	400		$	300			$	225		$	325		$	1,406		$	42		$	2,698
	Net assets of consolidated variable interest entities	$	247		$	136			$	80		$	222		$	346		$	22		$	1,053
	(a)	Restricted as collateral for non-recourse debt of VIEs.
	(b)	Non-recourse to the general assets of the applicable registrant.
	(c)	The amount for Progress Energy is equal to the amount for Duke Energy Progress Receivables Company, LLC (DEPR) and Duke Energy Florida Receivables Company, LLC (DEFR).
		December 31, 2013
		Duke Energy
		Duke Energy Carolinas			Duke Energy Progress
	(in millions)	DERF			DEPR(c)				CRC			Renewables			Other			Total
	ASSETS
	Current Assets
	Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	$	673		$	416			$	595		$	18		$	17		$	1,719
	Other	—			—				—			89			12			101
	Investments and Other Assets
	Other	—			—				—			29			51			80
	Property, Plant and Equipment
	Property, plant and equipment, cost(a)	—			—				—			1,662			18			1,680
	Accumulated depreciation and amortization	—			—				—			(170		)	(5		)	(175		)
	Regulatory Assets and Deferred Debits
	Other	1			1				—			34			—			36
	Total assets	$	674		$	417			$	595		$	1,662		$	93		$	3,441
	LIABILITIES AND EQUITY
	Current Liabilities
	Accounts payable	—			—				—			2			—			2
	Taxes accrued	—			—				—			10			—			10
	Current maturities of long-term debt	—			—				—			66			14			80
	Other	—			—				—			17			10			27
	Long-Term Debt(b)	400			300				325			907			34			1,966
	Deferred Credits and Other Liabilities														—
	Deferred income taxes	—			—				—			290			—			290
	Asset retirement obligations	—			—				—			26			—			26
	Other	1			—				—			17			13			31
	Total liabilities	$	401		$	300			$	325		$	1,335		$	71		$	2,432
	Net assets of consolidated variable interest entities	$	273		$	117			$	270		$	327		$	22		$	1,009
	(a)	Restricted as collateral for non-recourse debt of VIEs.
	(b)	Non-recourse to the general assets of the applicable registrant.
(c)	The amount Progress Energy is equal to the amount for DEPR.
The following table outlines amounts and expiration dates of the credit facilities.
	DERF		DEPR			DEFR
Credit facility amount (in millions)	$	400	$	300		$	225
Expiration date	Oct-16		Dec-16			Mar-17
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Schedule Of Variable Interest Entities	The tables below show VIEs not consolidated and how these entities impact the Consolidated Balance Sheets.
		December 31, 2014
		Duke Energy
	(in millions)	Renewables			Other				Total			Duke Energy			Duke Energy
												Ohio			Indiana
	Receivables	$	—		$	—			$	—		$	91		$	113
	Investments in equity method unconsolidated affiliates	150			38				188			—			—
	Investments and other assets	—			4				4			—			—
	Total assets(a)	$	150		$	42			$	192		$	91		$	113
	Other current liabilities	—			3				3			—			—
	Deferred credits and other liabilities	—			14				14			—			—
	Total liabilities	$	—		$	17			$	17		$	—		$	—
	Net assets (liabilities)	$	150		$	25			$	175		$	91		$	113
	(a)	Duke Energy Ohio recorded a pretax impairment charge of $94 million related to OVEC.
		December 31, 2013
		Duke Energy
	(in millions)	Renewables			Other				Total			Duke Energy Ohio			Duke Energy Indiana
	Receivables	$	—		$	—			$	—		$	114		$	143
	Investments in equity method unconsolidated affiliates	153			60				213			—			—
	Intangibles	—			96				96			96			—
	Investments and other assets	—			4				4			—			—
	Total assets	$	153		$	160			$	313		$	210		$	143
	Other current liabilities	—			3				3			—			—
	Deferred credits and other liabilities	—			15				15			—			—
	Total liabilities	$	—		$	18			$	18		$	—		$	—
	Net assets	$	153		$	142			$	295		$	210		$	143
Cinergy Receivables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Schedule Of Variable Interest Entities	Key assumptions used in estimating fair value are detailed in the following table.
		Duke Energy Ohio					Duke Energy Indiana
		2014		2013			2014			2013
	Anticipated credit loss ratio	0.6	%	0.6	%		0.3	%		0.3	%
	Discount rate	1.2	%	1.2	%		1.2	%		1.2	%
	Receivable turnover rate	12.8	%	12.8	%		10.5	%		10.3	%
	The following table shows the gross and net receivables sold.
		Duke Energy Ohio							Duke Energy Indiana
	(in millions)	2014			2013				2014			2013
	Receivables sold	$	273		$	290			$	310		$	340
	Less: Retained interests	91			114				113			143
	Net receivables sold	$	182		$	176			$	197		$	197
	The following table shows sales and cash flows related to receivables sold.
		Duke Energy Ohio										Duke Energy Indiana
		Years Ended December 31,										Years Ended December 31,
	(in millions)	2014			2013				2012			2014			2013			2012
	Sales
	Receivables sold	$	2,246		$	2,251			$	2,154		$	2,913		$	2,985		$	2,773
	Loss recognized on sale	11			12				13			11			11			12
	Cash Flows
	Cash proceeds from receivables sold	2,261			2,220				2,172			2,932			2,944			2,784
	Collection fees received	1			1				1			1			1			1
	Return received on retained interests	4			5				5			6			6			7

Common_Stock_Tables

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Line Items]
Schedule Of Earnings Per Share	The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted-average number of common shares outstanding to the diluted weighted-average number of common shares outstanding.
		Years Ended December 31,
	(in millions, except per share amounts)	2014		2013	2012
	Income from continuing operations attributable to Duke Energy common shareholders excluding impact of participating securities	2,446		2,565	1,588
	Weighted-average shares outstanding - basic	707		706	574
	Stock options, performance and restricted shares	—		—	1
	Weighted-average shares outstanding - diluted	707		706	575
	Earnings per share from continuing operations attributable to Duke Energy common shareholders
	Basic	$	3.46	3.64	2.77
	Diluted	$	3.46	3.63	2.77
	Potentially dilutive items excluded from the calculation(a)	2		2	1
	Dividends declared per common share	$	3.15	3.09	3.03
	(a)	Stock options and performance and unvested stock awards were not included in the dilutive securities calculation because either the option exercise prices were greater than the average market price of the common shares during those periods, or performance measures related to the awards had not yet been met.

Severance_Tables

Severance (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Schedule of Severance Liability	Amounts included in the table below represent direct and allocated severance and related expense recorded by the Duke Energy Registrants, and are in Operation, maintenance and other within Operating Expenses on the Consolidated Statements of Operations.
		Year Ended December 31,
	(in millions)	2013		2012
	Duke Energy(a)	$	34	$	201
	Duke Energy Carolinas	8		63
	Progress Energy	19		82
	Duke Energy Progress	14		55
	Duke Energy Florida	5		27
	Duke Energy Ohio	2		21
	Duke Energy Indiana	2		18
	(a)	Includes $5 million and $14 million of accelerated stock award expense and $2 million and $19 million of COBRA and health care reimbursement expenses for 2013 and 2012, respectively.
Schedule of Severance Expense	Amounts included in the table below represent the severance liability for past and ongoing severance plans. Amounts for Subsidiary Registrants do not include allocated expense or associated cash payments. Amounts for Duke Energy Indiana are not material.
	(in millions)	Balance at December 31, 2013		Provision / Adjustments			Cash Reductions			Balance at December 31, 2014
	Duke Energy	$	64	$	5		$	(41	)	28
	Duke Energy Carolinas	5		2			(5		)	2
	Progress Energy	44		(10		)	(16		)	18
	Duke Energy Progress	11		—			(10		)	1
	Duke Energy Florida	24		(1		)	(6		)	17
	Duke Energy Ohio	2		5			(1		)	6

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Total Stock-Based Compensation Expense, net of tax	The following table summarizes the total expense recognized by each of the Duke Energy Registrants, net of tax, for stock-based compensation.
		Years Ended December 31,
	(in millions)	2014			2013			2012
	Duke Energy	$	38		$	52		$	48
	Duke Energy Carolinas	12			13			12
	Progress Energy	14			23			25
	Duke Energy Progress	9			14			16
	Duke Energy Florida	5			9			9
	Duke Energy Ohio	5			4			4
	Duke Energy Indiana	3			4			4
Schedule Of Stock-Based Compensation Expense	Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense, and stock-based compensation costs capitalized are included in the following table.
		Years Ended December 31,
	(in millions)	2014			2013			2012
	Restricted stock unit awards	$	39		$	49		$	43
	Performance awards	22			34			33
	Stock options	—			2			2
	Pretax stock-based compensation cost	$	61		$	85		$	78
	Tax benefit associated with stock-based compensation expense	$	23		$	33		$	30
	Stock-based compensation costs capitalized	4			3			2
Schedule of Share-based Compensation, Stock Options, Activity	The following table summarizes information about stock options outstanding.
		Options		Weighted-Average Exercise Price (per share)			Weighted-Average Remaining Life		Aggregate Intrinsic Value
		(in thousands)							(in millions)
	Outstanding at December 31, 2013	793		$	61
	Exercised	(420	)	59
	Outstanding at December 31, 2014	373		64			6 years, 10 months		$	7
	Exercisable at December 31, 2014	53		46			1 year		2
	Options expected to vest	320		67			7 years, 10 months		5
Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Exercises	The following table summarizes additional information related to stock options exercised and granted.
		Years Ended December 31,
		2014			2013			2012
	Intrinsic value of options exercised (in millions)	$	6		$	26		$	17
	Tax benefit related to options exercised (in millions)	2			10			7
	Cash received from options exercised (in millions)	25			9			21
	Stock options granted (in thousands)	—			310			340
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	Restricted stock unit awards issued and outstanding generally vest over periods from immediate to 3 years. Fair value amounts are based on the market price of Duke Energy's common stock at the grant date. The following table includes information related to restricted stock unit awards.
		Years Ended December 31,
		2014			2013			2012
	Shares awarded (in thousands)	557			612			443
	Fair value (in millions)	$	40		$	42		$	28
	The following table summarizes information about restricted stock unit awards outstanding.
		Shares		Weighted-Average
		(in thousands)		Grant Date Fair Value
				(Per Share)
	Outstanding at December 31, 2013	1,400		$	66
	Granted	557		71
	Vested	(832	)	62
	Forfeited	(45	)	68
	Outstanding at December 31, 2014	1,080		69
	Restricted stock unit awards expected to vest	1,057		69
Schedule of Performance Awards	The following table includes information related to performance awards.
		Years Ended December 31,
		2014			2013			2012
	Shares awarded (in thousands)	542			633			352
	Fair value (in millions)	$	19		$	28		$	19
Schedule of Nonvested Performance-based Units Activity	The following table summarizes information about stock-based performance awards outstanding at the maximum level.
		Shares		Weighted-Average
		(in thousands)		Grant Date Fair Value
				(per share)
	Outstanding at December 31, 2013	1,822		$	46
	Granted	542		34
	Vested	(524	)	52
	Forfeited	(213	)	37
	Outstanding at December 31, 2014	1,627		42
	Stock-based performance awards expected to vest	1,418		42

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Contributions	Duke Energy’s policy is to fund amounts on an actuarial basis to provide assets sufficient to meet benefit payments to be paid to plan participants. The following table includes information related to the Duke Energy Registrants’ contributions to its U.S. qualified defined benefit pension plans.
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Anticipated Contributions:
	2015	$	302			$	91			$	83			$	42			$	40			$	8		$	19
	Contributions Made:
	2014	$	—			$	—			$	—			$	—			$	—			$	—		$	—
	2013	250				—				250				63				133				—			—
	2012	304				—				346				141				128				—			—
Employee Savings Plan Matching Contributions	The following table includes pretax employer matching contributions made by Duke Energy and expensed by the Subsidiary Registrants.
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Years ended December 31,
	2014(a)	$	143			$	47			$	43			$	30			$	14			$	3		$	7
	2013	134				45				45				25				14				3			7
	2012	107				37				45				24				15				4			6
	(a)	For 2014, amounts include the additional employer contribution of 4 percent of eligible pay per pay period for employees not eligible to participate in a defined benefit plan.
Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value and Allocation of Plan Assets	The following tables provide the fair value measurement amounts for the Duke Energy Master Retirement Trust qualified pension and other post-retirement assets.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1				Level 2				Level 3
	Equity securities	$	2,346			$	1,625			$	721			$	—
	Corporate debt securities	4,349				—				4,348				1
	Short-term investment funds	333				171				162				—
	Partnership interests	298				—				—				298
	Hedge funds	146				—				146				—
	Real estate limited partnerships	104				—				—				104
	U.S. government securities	917				—				916				1
	Guaranteed investment contracts	32				—				—				32
	Governments bonds - foreign	44				—				44				—
	Cash	30				30				—				—
	Government and commercial mortgage backed securities	9				—				9				—
	Net pending transactions and other investments	10				(10		)		20				—
	Total assets(a)	$	8,618			$	1,816			$	6,366			$	436
	(a)	Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio and Duke Energy Indiana were allocated approximately 28 percent, 31 percent, 15 percent, 16 percent, 5 percent and 8 percent, respectively, of the Duke Energy Master Retirement Trust assets at December 31, 2014. Accordingly, all Level 1, 2 and 3 amounts included in the table above are allocable to the Subsidiary Registrants using these percentages.
		December 31, 2013
	(in millions)	Total Fair Value				Level 1				Level 2				Level 3
	Equity securities	$	2,877			$	1,801			$	1,022			$	54
	Corporate debt securities	2,604				—				2,601				3
	Short-term investment funds	1,158				254				904				—
	Partnership interests	307				—				—				307
	Hedge funds	164				—				111				53
	Real estate limited partnerships	95				—				—				95
	U.S. government securities	927				—				927				—
	Guarantees investment contracts	33				—				—				33
	Governments bonds - foreign	19				—				18				1
	Cash	58				58				—				—
	Asset backed securities	7				—				7				—
	Net pending transactions and other investments	12				7				5				—
	Total assets(a)	$	8,261			$	2,120			$	5,595			$	546
	(a)	Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio and Duke Energy Indiana were allocated approximately 28 percent, 35 percent, 16 percent, 16 percent, 5 percent and 8 percent, respectively, of the Duke Energy Master Retirement Trust assets at December 31, 2013. Accordingly, all Level 1, 2 and 3 amounts included in the table above are allocable to the Subsidiary Registrants using these percentages.
	The following table includes the target asset allocations by asset class at December 31, 2014 and the actual asset allocations for the Duke Energy Master Retirement Trust.
					Actual Allocation at December 31,
		Target Allocation			2014			2013
	U.S. equity securities	10	%		10	%		10	%
	Non-U.S. equity securities	8	%		8	%		8	%
	Global equity securities	10	%		10	%		10	%
	Global private equity securities	3	%		3	%		3	%
	Debt securities	63	%		63	%		63	%
	Hedge funds	2	%		3	%		3	%
	Real estate and cash	2	%		1	%		1	%
	Other global securities	2	%		2	%		2	%
	Total	100	%		100	%		100	%
Master Trust Level 3 Rollforward	The following table provides a reconciliation of beginning and ending balances of assets of master trusts measured at fair value on a recurring basis where the determination of fair value includes significant unobservable inputs (Level 3).
	(in millions)	2014				2013
	Balance at January 1	$	546			$	352
	Combination of trust assets(a)	—				288
	Purchases, sales, issuances and settlements
	Purchases	17				25
	Sales	(164		)		(152		)
	Total gains (losses) and other, net	37				33
	Balance at December 31	$	436			$	546
	(a)	As of January 1, 2013, assets previously held in the Progress Energy Master Retirement Trust were transferred into the Duke Energy Master Retirement Trust.
Voluntary Employee Beneficiary Association [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value and Allocation of Plan Assets	The following table presents target and actual asset allocations for VEBA I at December 31, 2014.
					Actual Allocation at December 31,
		Target Allocation			2014			2013
	U.S. equity securities	30	%		29	%		29	%
	Debt securities	45	%		28	%		29	%
	Cash	25	%		43	%		42	%
	Total	100	%		100	%		100	%
	The following tables provide the fair value measurement amounts for VEBA I other post-retirement assets.
		December 31, 2014
	(in millions)	Total Fair Value				Level 1			Level 2				Level 3
	Cash and cash equivalents	$	21			—			$	21			—
	Equity securities	14				—			14				—
	Debt securities	13				—			13				—
	Total assets	$	48			—			$	48			—
		December 31, 2013
	(in millions)	Total Fair Value				Level 1			Level 2				Level 3
	Cash and cash equivalents	$	21			—			$	21			—
	Equity securities	15				—			15				—
	Debt securities	15				—			15				—
	Total assets	$	51			—			$	51			—
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Components of Net Periodic Pension Costs	Components of Net Periodic Pension Costs
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	135			$	41			$	40			$	21			$	20			$	4		$	9
	Interest cost on projected benefit obligation	344				85				112				54				57				20			29
	Expected return on plan assets	(511		)		(132		)		(173		)		(85		)		(85		)		(27		)	(41		)
	Amortization of actuarial loss	150				36				68				32				32				4			13
	Amortization of prior service credit	(15		)		(8		)		(3		)		(2		)		(1		)		—			—
	Other	8				2				3				1				1				—			1
	Net periodic pension costs	$	111			$	24			$	47			$	21			$	24			$	1		$	11
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	167			$	49			$	60			$	22			$	30			$	6		$	11
	Interest cost on projected benefit obligation	320				80				116				50				53				21			28
	Expected return on plan assets	(549		)		(148		)		(199		)		(94		)		(87		)		(31		)	(46		)
	Amortization of actuarial loss	244				60				101				46				49				13			24
	Amortization of prior service (credit) cost	(11		)		(6		)		(4		)		(1		)		(2		)		—			1
	Other	7				2				2				1				1				—			1
	Net periodic pension costs	$	178			$	37			$	76			$	24			$	44			$	9		$	19
		Year Ended December 31, 2012
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	122			$	35			$	63			$	25			$	30			$	6		$	9
	Interest cost on projected benefit obligation	307				90				127				58				56				31			30
	Expected return on plan assets	(472		)		(146		)		(188		)		(96		)		(81		)		(45		)	(46		)
	Amortization of actuarial loss	144				45				93				37				48				10			15
	Amortization of prior service cost (credit)	10				1				9				8				(1		)		1			1
	Other	6				2				2				1				1				—			—
	Net periodic pension costs	$	117			$	27			$	106			$	33			$	53			$	3		$	9
Amounts Recognized in AOCI and Regulatory Assets and Liabilities	Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net increase (decrease)	$	112			$	30			$	(73	)		$	(17	)		$	11			$	17		$	4
	Accumulated other comprehensive (income) loss
	Deferred income tax expense	$	(10	)		—				(2		)		—				—				—			—
	Actuarial losses arising during the year	29				—				—				—				—				—			—
	Prior year service credit arising during the year	—				—				—				—				—				—			—
	Amortization of prior year actuarial losses	(9		)		—				—				—				—				—			—
	Reclassification of actuarial losses to regulatory assets	(1		)		—				—				—				—				—			—
	Net amount recognized in accumulated other comprehensive income	$	9			$	—			$	(2	)		$	—			$	—			$	—		$	—
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net decrease	$	(788	)		$	(205	)		$	(253	)		$	(109	)		$	(146	)		$	(96	)	$	(99	)
	Accumulated other comprehensive (income) loss
	Deferred income tax benefit	$	18			$	—			$	—			$	—			$	—			$	—		$	—
	Actuarial gains arising during the year	(33		)		—				(2		)		—				—				—			—
	Prior year service credit arising during the year	(1		)		—				—				—				—				—			—
	Amortization of prior year actuarial losses	(15		)		—				(3		)		—				—				—			—
	Reclassification of actuarial losses to regulatory assets	3				—				—				—				—				—			—
	Net amount recognized in accumulated other comprehensive income	$	(28	)		$	—			$	(5	)		$	—			$	—			$	—		$	—
Reconciliation of Funded Status to Net Amount Recognized	Reconciliation of Funded Status to Net Amount Recognized
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Change in Projected Benefit Obligation
	Obligation at prior measurement date	$	7,510			$	1,875			$	2,739			$	1,172			$	1,233			$	442		$	632
	Service cost	135				41				40				21				20				4			9
	Interest cost	344				85				112				54				57				20			29
	Actuarial loss(a)	618				132				211				98				105				41			41
	Transfers	—				37				(375		)		(61		)		(9		)		(6		)	—
	Plan amendments	(4		)		(1		)		—				—				—				(1		)	—
	Benefits paid	(496		)		(116		)		(170		)		(97		)		(71		)		(31		)	(38		)
	Obligation at measurement date	$	8,107			$	2,053			$	2,557			$	1,187			$	1,335			$	469		$	673
	Accumulated Benefit Obligation at measurement date	$	7,966			$	2,052			$	2,519			$	1,187			$	1,297			$	459		$	645
	Change in Fair Value of Plan Assets
	Plan assets at prior measurement date	$	8,142			$	2,162			$	2,944			$	1,330			$	1,299			$	448		$	654
	Actual return on plan assets	852				217				300				149				144				45			65
	Benefits paid	(496		)		(116		)		(170		)		(97		)		(71		)		(31		)	(38		)
	Transfers	—				37				(352		)		(61		)		(9		)		(6		)	—
	Plan assets at measurement date	$	8,498			$	2,300			$	2,722			$	1,321			$	1,363			$	456		$	681
	Funded status of plan	$	391			$	247			$	165			$	134			$	28			$	(13	)	$	8
	(a)	Includes an increase in benefit obligation of $180 million as a result of changes in Duke Energy's mortality assumptions.
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Change in Projected Benefit Obligation
	Obligation at prior measurement date	8,030				2,028				2,868				1,264				1,309				527			684
	Service cost	167				49				60				22				30				6			11
	Interest cost	320				80				116				50				53				21			28
	Actuarial gains	(399		)		(73		)		(118		)		(26		)		(75		)		(71		)	(56		)
	Transfers	—				(26		)		(7		)		(45		)		(17		)		(2		)	(2		)
	Plan amendments	(41		)		(13		)		(19		)		(8		)		(7		)		—			—
	Benefits paid	(567		)		(170		)		(161		)		(85		)		(60		)		(39		)	(33		)
	Obligation at measurement date	7,510				1,875				2,739				1,172				1,233				442			632
	Accumulated Benefit Obligation at measurement date	7,361				1,875				2,698				1,172				1,192				429			608
	Change in Fair Value of Plan Assets
	Plan assets at prior measurement date	7,754				2,151				2,647				1,289				1,150				446			627
	Actual return on plan assets	705				207				215				108				93				43			62
	Benefits paid	(567		)		(170		)		(161		)		(85		)		(60		)		(39		)	(33		)
	Transfers	—				(26		)		(7		)		(45		)		(17		)		(2		)	(2		)
	Employer contributions	250				—				250				63				133				—			—
	Plan assets at measurement date	$	8,142			$	2,162			$	2,944			$	1,330			$	1,299			$	448		$	654
	Funded status of plan	$	632			$	287			$	205			$	158			$	66			$	6		$	22
Amounts Recognized in the Consolidated Balance Sheet	Amounts Recognized in the Consolidated Balance Sheets
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Prefunded pension(a)	$	441			$	247			$	165			$	134			$	28			$	—		$	8
	Non-current pension liability(b)	$	50			$	—			$	—			$	—			$	—			$	13		$	—
	Net asset recognized	$	391			$	247			$	165			$	134			$	28			$	(13	)	$	8
	Regulatory assets	$	1,711			$	407			$	753			$	346			$	406			$	65		$	151
	Accumulated other comprehensive (income) loss
	Deferred income tax asset	$	(51	)		$	—			$	(11	)		$	—			$	—			$	—		$	—
	Prior service credit	(5		)		—				—				—				—				—			—
	Net actuarial loss	140				—				21				—				—				—			—
	Net amounts recognized in accumulated other comprehensive loss(c)	$	84			$	—			$	10			$	—			$	—			$	—		$	—
	Amounts to be recognized in net periodic pension expense in the next year
	Unrecognized net actuarial loss	$	166			$	39			$	65			$	34			$	31			$	6		$	14
	Unrecognized prior service credit	(15		)		(8		)		(3		)		(2		)		(1		)		—			—
		December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Prefunded pension(a)	$	632			$	287			$	230			$	158			$	66			$	2		$	75
	Non-current pension liability(b)	$	—			$	—			$	25			$	—			$	—			$	(4	)	$	53
	Net asset recognized	$	632			$	287			$	205			$	158			$	66			$	6		$	22
	Regulatory assets	$	1,599			$	377			$	826			$	363			$	395			$	48		$	147
	Accumulated other comprehensive (income) loss
	Deferred income tax asset	$	(41	)		$	—			$	(9	)		$	—			$	—			$	—		$	—
	Prior service credit	(5		)		—				—				—				—				—			—
	Net actuarial loss	121				—				21				—				—				—			—
	Net amounts recognized in accumulated other comprehensive loss(c)	$	75			$	—			$	12			$	—			$	—			$	—		$	—
	(a)	Included in Other within Investments and Other Assets on the Consolidated Balance Sheets.
	(b)	Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.
	(c)	Excludes accumulated other comprehensive income of $22 million and $16 million as of 2014 and 2013, respectively, net of tax, associated with a Brazilian retirement plan.
Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets	Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy Ohio
	Projected benefit obligation	$	702			$	315
	Accumulated benefit obligation	672				306
	Fair value of plan assets	652				302
Assumptions Used for Pension Benefits Accounting	The following tables present the assumptions or range of assumptions used for pension benefit accounting.
			December 31,
			2014					2013					2012(a)
	Benefit Obligations
	Discount rate					4.10%					4.70%					4.10%
	Salary increase		4	%	-	4.40%		4	%	-	4.40%		4	%	-	4.30%
	Net Periodic Benefit Cost
	Discount rate					4.70%					4.10%		4.6	%	-	5.10%
	Salary increase		4	%	-	4.40%		4	%	-	4.30%		4	%	-	4.40%
	Expected long-term rate of return on plan assets					6.75%					7.75%		8	%	-	8.25%
	(a)	For Progress Energy plans, the assumptions used in 2012 to determine net periodic pension costs reflect remeasurement as of July 1, 2012, due to the merger between Duke Energy and Progress Energy.
Expected Benefit Payments	Expected Benefit Payments
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Years ending December 31,
	2015	$	584		$	175		$	150		$	80		$	67		$	34		$	45
	2016	604			184			158			85			70			35			46
	2017	616			195			161			86			73			34			45
	2018	625			200			165			87			76			34			46
	2019	626			194			168			88			78			34			46
	2020 - 2024	3,107			924			868			437			420			168			229
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Components of Net Periodic Pension Costs	Components of Net Periodic Pension Costs
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	3		$	—		$	1		$	1		$	—		$	—		$	—
	Interest cost on projected benefit obligation	14			1			5			1			2			—			—
	Amortization of actuarial loss	3			—			2			—			—			—			—
	Amortization of prior service credit	(1		)	—			(1		)	—			—			—			—
	Net periodic pension costs	$	19		$	1		$	7		$	2		$	2		$	—		$	—
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	3		$	—		$	1		$	1		$	—		$	—		$	—
	Interest cost on projected benefit obligation	13			1			7			1			1			—			—
	Amortization of actuarial loss	5			—			3			1			1			—			—
	Amortization of prior service credit	(1		)	—			(1		)	—			—			—			—
	Net periodic pension costs	$	20		$	1		$	10		$	3		$	2		$	—		$	—
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	2		$	—		$	2		$	1		$	—		$	—		$	—
	Interest cost on projected benefit obligation	12			1			8			1			2			—			—
	Amortization of actuarial loss	4			—			5			1			—			—			—
	Amortization of prior service cost (credit)	1			—			(1		)	—			—			—			—
	Net periodic pension costs	$	19		$	1		$	14		$	3		$	2		$	—		$	—
Amounts Recognized in AOCI and Regulatory Assets and Liabilities	Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net increase	$	44		$	1		$	14		$	4		$	19		$	1		$	2
	Regulatory liabilities, net decrease	$	(7	)	$	—		$	—		$	—		$	—		$	—		$	—
	Accumulated other comprehensive (income) loss
	Deferred income tax benefit	$	4		$	—		$	5		$	—		$	—		$	—		$	—
	Actuarial gains arising during the year	(9		)	—			(11		)	—			—			—			—
	Net amount recognized in accumulated other comprehensive loss (income)	$	(5	)	$	—		$	(6	)	$	—		$	—		$	—		$	—
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net (decrease) increase	$	(14	)	$	1		$	(16	)	$	(4	)	$	(3	)	$	—		$	(2	)
	Regulatory liabilities, net increase	$	5		$	—		$	—		$	—		$	—		$	—		$	—
	Accumulated other comprehensive (income) loss
	Deferred income tax benefit	$	—		$	—		$	1		$	—		$	—		$	—		$	—
	Actuarial losses (gains) arising during the year	2			—			(5		)	—			—			—			—
	Prior year service credit arising during the year	(1		)	—			—			—			—			—			—
	Net amount recognized in accumulated other comprehensive loss (income)	$	1		$	—		$	(4	)	$	—		$	—		$	—		$	—
Reconciliation of Funded Status to Net Amount Recognized	Reconciliation of Funded Status to Net Amount Recognized
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Change in Projected Benefit Obligation
	Obligation at prior measurement date	$	304		$	15		$	140		$	34		$	39		$	3		$	5
	Service cost	3			—			1			1			—			—			—
	Interest cost	14			1			5			1			2			—			—
	Actuarial losses(a)	43			2			11			2			20			1			1
	Settlements	—			—			—			—			—			—			—
	Plan amendments	—			—			—			—			—			—			—
	Transfers	—			—			(32		)	—			4			—			—
	Benefits paid	(27		)	(2		)	(9		)	(3		)	(4		)	—			(1		)
	Obligation at measurement date	$	337		$	16		$	116		$	35		$	61		$	4		$	5
	Accumulated Benefit Obligation at measurement date	$	333		$	15		$	116		$	35		$	61		$	4		$	5
	Change in Fair Value of Plan Assets
	Plan assets at prior measurement date	—			—			—			—			—			—			—
	Benefits paid	(27		)	(2		)	(9		)	(3		)	(4		)	—			(1		)
	Employer contributions	27			2			9			3			4			—			1
	Plan assets at measurement date	$	—		$	—		$	—		$	—		$	—		$	—		$	—
	(a)	Includes an increase in benefit obligation of $21 million as a result of changes in Duke Energy's mortality assumptions.
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Change in Projected Benefit Obligation
	Obligation at prior measurement date	$	335		$	16		$	176		$	38		$	45		$	4		$	5
	Service cost	3			—			1			1			—			—			—
	Interest cost	13			1			7			1			1			—			—
	Actuarial (gains) losses	(15		)	1			(11		)	(3		)	(3		)	(1		)	—
	Settlements	(5		)	—			—			—			—			—			—
	Plan amendments	(1		)	—			—			—			—			—			—
	Transfers	—			—			(21		)	—			—			—			—
	Benefits paid	(26		)	(3		)	(12		)	(3		)	(4		)	—			—
	Obligation at measurement date	$	304		$	15		$	140		$	34		$	39		$	3		$	5
	Accumulated Benefit Obligation at measurement date	$	302		$	15		$	140		$	34		$	39		$	3		$	5
	Change in Fair Value of Plan Assets
	Plan assets at prior measurement date	—			—			—			—			—			—			—
	Benefits paid	(26		)	(3		)	(12		)	(3		)	(4		)	—			—
	Employer contributions	26			3			12			3			4			—			—
	Plan assets at measurement date	$	—		$	—		$	—		$	—		$	—		$	—		$	—
Amounts Recognized in the Consolidated Balance Sheet	Amounts Recognized in the Consolidated Balance Sheets
		December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Current pension liability(a)	$	27		$	2		$	8		$	3		$	4		$	—		$	—
	Non-current pension liability(b)	310			14			108			32			57			4			5
	Total accrued pension liability	$	337		$	16		$	116		$	35		$	61		$	4		$	5
	Regulatory assets	$	89		$	5		$	32		$	7		$	25		$	1		$	2
	Regulatory liabilities	$	—		$	—		$	—		$	—		$	—		$	—		$	—
	Accumulated other comprehensive (income) loss
	Deferred income tax asset	4			—			$	2		—			—			—			—
	Prior service credit	(1		)	—			—			—			—			—			—
	Net actuarial gain	(8		)	—			(4		)	—			—			—			—
	Net amounts recognized in accumulated other comprehensive income	$	(5	)	$	—		$	(2	)	$	—		$	—		$	—		$	—
	Amounts to be recognized in net periodic pension expense in the next year
	Unrecognized net actuarial loss	$	6		—			$	2		$	1		2			—			—
	Unrecognized prior service credit	(1		)	—			—			—			—			—			—
		December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Current pension liability(a)	$	30		$	2		$	11		$	2		$	3		$	—		$	—
	Non-current pension liability(b)	274			13			129			32			36			3			5
	Total accrued pension liability	$	304		$	15		$	140		$	34		$	39		$	3		$	5
	Regulatory assets	$	45		$	4		$	18		$	3		$	6		$	—		$	—
	Regulatory liabilities	$	7		$	—		$	—		$	—		$	—		$	—		$	—
	Accumulated other comprehensive (income) loss
	Deferred income tax asset	$	—		$	—		$	(3	)	$	—		$	—		$	—		$	—
	Prior service credit	(1		)	—			—			—			—			—			—
	Net actuarial loss	1			—			7			—			—			—			—
	Net amounts recognized in accumulated other comprehensive loss	$	—		$	—		$	4		$	—		$	—		$	—		$	—
	(a)	Included in Other within Current Liabilities on the Consolidated Balance Sheets.
	(b)	Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.
Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets	Information for Plans with Accumulated Benefit Obligation in Excess of Plan Assets
		December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Projected benefit obligation	$	337		$	16		$	116		$	35		$	61		$	4		$	5
	Accumulated benefit obligation	333			15			116			35			61			4			5
		December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Projected benefit obligation	$	304		$	15		$	140		$	34		$	39		$	3		$	5
	Accumulated benefit obligation	302			15			140			34			39			3			5
Assumptions Used for Pension Benefits Accounting	The following tables present the assumptions used for pension benefit accounting.
			December 31,
			2014			2013			2012(a)
	Benefit Obligations
	Discount rate		4.1	%		4.7	%					4.10%
	Salary increase		4.4	%		4.4	%					4.30%
	Net Periodic Benefit Cost
	Discount rate		4.7	%		4.1	%		4.6	%	-	5.10%
	Salary increase		4.4	%		4.3	%					4.40%
	(a)	For Progress Energy plans, the assumptions used in 2012 to determine net periodic pension costs reflect remeasurement as of July 1, 2012, due to the merger between Duke Energy and Progress Energy.
Expected Benefit Payments	Expected Benefit Payments
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Years ending December 31,
	2015	$	28		$	2		$	8		$	3		$	4		$	—		$	—
	2016	27			2			8			3			4			—			—
	2017	27			2			8			3			4			—			—
	2018	24			2			8			3			4			—			—
	2019	24			2			8			3			4			—			—
	2020 - 2024	116			6			38			13			19			2			2
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Components of Net Periodic Pension Costs	Components of Net Periodic Other Post-Retirement Benefit Costs
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	10			$	2			$	4			$	1			$	3			$	—		$	1
	Interest cost on accumulated post-retirement benefit obligation	49				12				22				11				12				2			5
	Expected return on plan assets	(13		)		(9		)		—				—				—				—			(1		)
	Amortization of actuarial loss (gain)	39				3				42				31				10				(2		)	—
	Amortization of prior service credit	(125		)		(11		)		(95		)		(73		)		(21		)		—			—
	Net periodic post-retirement benefit costs	$	(40	)		$	(3	)		$	(27	)		$	(30	)		$	4			$	—		$	5
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	24			$	2			$	18			$	9			$	7			$	1		$	1
	Interest cost on accumulated post-retirement benefit obligation	68				13				41				22				16				2			5
	Expected return on plan assets	(14		)		(11		)		—				—				—				(1		)	(1		)
	Amortization of actuarial loss (gain)	52				3				57				34				16				(1		)	1
	Amortization of prior service credit	(41		)		(7		)		(30		)		(20		)		(6		)		(1		)	—
	Net periodic post-retirement benefit costs	$	89			$	—			$	86			$	45			$	33			$	—		$	6
		Year Ended December 31, 2012
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Service cost	$	16			$	2			$	17			$	8			$	7			$	1		$	1
	Interest cost on accumulated post-retirement benefit obligation	56				15				43				23				18				3			6
	Expected return on plan assets	(17		)		(10		)		(2		)		—				(2		)		(1		)	(1		)
	Amortization of actuarial loss (gain)	14				3				35				20				12				(2		)	—
	Amortization of prior service credit	(8		)		(5		)		—				—				—				(1		)	—
	Amortization of net transition liability	10				7				4				—				3				—			—
	Special termination benefit cost	9				1				5				2				1				—			—
	Net periodic post-retirement benefit costs	$	80			$	13			$	102			$	53			$	39			$	—		$	6
Amounts Recognized in AOCI and Regulatory Assets and Liabilities	Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net increase (decrease)	$	162			$	34			$	129			$	97			$	(4	)		$	—		$	(7	)
	Regulatory liabilities, net increase (decrease)	$	249			$	76			$	122			$	61			$	61			$	(2	)	$	14
	Accumulated other comprehensive (income) loss
	Deferred income tax benefit	$	1			$	—			$	1			$	—			$	—			$	—		$	—
	Actuarial losses (gains) arising during the year	1				—				(2		)		—				—				—			—
	Prior year service credit arising during the year	(6		)		—				—				—				—				—			—
	Amortization of prior year prior service credit	2				—				—				—				—				—			—
	Net amount recognized in accumulated other comprehensive income	$	(2	)		$	—			$	(1	)		$	—			$	—			$	—		$	—
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Regulatory assets, net (decrease) increase	$	(683	)		$	(51	)		$	(634	)		$	(388	)		$	(166	)		$	—		$	(6	)
	Regulatory liabilities, net increase (decrease)	$	30			$	—			$	—			$	—			$	—			$	3		$	9
	Accumulated other comprehensive (income) loss
	Deferred income tax benefit	$	2			$	—			$	—			$	—			$	—			$	—		$	—
	Actuarial gains arising during the year	(4		)		—				—				—				—				—			—
	Prior year service credit arising during the year	(3		)		—				—				—				—				—			—
	Amortization of prior year actuarial loss	1				—				—				—				—				—			—
	Net amount recognized in accumulated other comprehensive income	$	(4	)		$	—			$	—			$	—			$	—			$	—		$	—
Reconciliation of Funded Status to Net Amount Recognized	Reconciliation of Funded Status to Accrued Other Post-Retirement Benefit Costs
		Year Ended December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Change in Projected Benefit Obligation
	Accumulated post-retirement benefit obligation at prior measurement date	$	1,106			$	265			$	533			$	233			$	253			$	42		$	118
	Service cost	10				2				4				1				3				—			1
	Interest cost	49				12				22				11				12				2			5
	Plan participants' contributions	25				10				8				4				4				—			2
	Actuarial gains(a)	(87		)		(35		)		(19		)		(21		)		—				—			(20		)
	Transfers	—				1				(48		)		(2		)		—				(1		)	—
	Plan amendments	(85		)		(4		)		(77		)		—				(78		)		(1		)	—
	Benefits paid	(103		)		(31		)		(44		)		(19		)		(24		)		(3		)	(10		)
	Accrued retiree drug subsidy	1				—				—				—				—				—			—
	Accumulated post-retirement benefit obligation at measurement date	$	916			$	220			$	379			$	207			$	170			$	39		$	96
	Change in Fair Value of Plan Assets
	Plan assets at prior measurement date	$	214			$	143			—				—				—				$	8		$	18
	Actual return on plan assets	18				12				—				—				—				—			2
	Benefits paid	(103		)		(31		)		(44		)		(19		)		(24		)		(3		)	(10		)
	Transfers	—				(1		)		—				—				—				—			—
	Employer contributions	73				12				36				14				20				3			11
	Plan participants' contributions	25				10				8				4				4				—			2
	Plan assets at measurement date	$	227			$	145			$	—			$	(1	)		$	—			$	8		$	23
	(a)	Includes an increase in benefit obligation of $7 million as a result of changes in Duke Energy's mortality assumptions.
		Year Ended December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Change in Projected Benefit Obligation
	Accumulated post-retirement benefit obligation at prior measurement date	$	1,794			$	316			$	1,128			$	612			$	413			$	48		$	136
	Service cost	24				2				18				9				7				1			1
	Interest cost	68				13				41				22				16				2			5
	Plan participants' contributions	47				15				14				6				7				3			3
	Actuarial gains	(227		)		(32		)		(156		)		(73		)		(70		)		(6		)	(12		)
	Transfers	—				—				(1		)		(8		)		—				—			—
	Plan amendments	(476		)		(16		)		(455		)		(311		)		(91		)		—			(3		)
	Benefits paid	(132		)		(36		)		(60		)		(26		)		(31		)		(6		)	(14		)
	Accrued retiree drug subsidy	8				3				4				2				2				—			2
	Accumulated post-retirement benefit obligation at measurement date	$	1,106			$	265			$	533			$	233			$	253			$	42		$	118
	Change in Fair Value of Plan Assets
	Plan assets at prior measurement date	$	198			$	134			$	—			$	—			$	—			$	7		$	17
	Actual return on plan assets	18				13				—				—				—				2			2
	Benefits paid	(132		)		(36		)		(60		)		(26		)		(31		)		(6		)	(14		)
	Transfers	—				(1		)		—				—				—				—			—
	Employer contributions	83				18				46				20				24				2			10
	Plan participants' contributions	47				15				14				6				7				3			3
	Plan assets at measurement date	$	214			$	143			$	—			$	—			$	—			$	8		$	18
Amounts Recognized in the Consolidated Balance Sheet	Amounts Recognized in the Consolidated Balance Sheets
		December 31, 2014
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Current post-retirement liability(a)	$	35			$	—			$	29			$	16			$	14			$	2		$	—
	Non-current post-retirement liability(b)	654				75				350				192				156				29			73
	Total accrued post-retirement liability	$	689			$	75			$	379			$	208			$	170			$	31		$	73
	Regulatory assets	$	—			$	—			$	—			$	—			$	—			$	—		$	64
	Regulatory liabilities	$	380			$	76			$	122			$	61			$	61			$	19		$	91
	Accumulated other comprehensive (income) loss
	Deferred income tax liability	$	5			$	—			$	1			$	—			$	—			$	—		$	—
	Prior service credit	(9		)		—				—				—				—				—			—
	Net actuarial gain	(5		)		—				(2		)		—				—				—			—
	Net amounts recognized in accumulated other comprehensive income	$	(9	)		$	—			$	(1	)		$	—			$	—			$	—		$	—
	Amounts to be recognized in net periodic pension expense in the next year
	Unrecognized net actuarial loss (gain)	$	16			$	(1	)		$	28			$	18			$	10			$	(2	)	$	—
	Unrecognized prior service credit	(140		)		(14		)		(103		)		(68		)		(35		)		—			—
		December 31, 2013
	(in millions)	Duke Energy				Duke Energy Carolinas				Progress Energy				Duke Energy Progress				Duke Energy Florida				Duke Energy Ohio			Duke Energy Indiana
	Current post-retirement liability(a)	$	39			$	—			$	36			$	17			$	16			$	2		$	—
	Non-current post-retirement liability(b)	853				122				497				216				237				32			100
	Total accrued post-retirement liability	$	892			$	122			$	533			$	233			$	253			$	34		$	100
	Regulatory assets	$	(162	)		$	(34	)		$	(129	)		$	(97	)		$	4			$	—		$	71
	Regulatory liabilities	$	131			$	—			$	—			$	—			$	—			$	21		$	77
	Accumulated other comprehensive (income) loss
	Deferred income tax liability	$	4			$	—			$	—			$	—			$	—			$	—		$	—
	Prior service credit	(5		)		—				—				—				—				—			—
	Net actuarial gain	(6		)		—				—				—				—				—			—
	Net amounts recognized in accumulated other comprehensive income	$	(7	)		$	—			$	—			$	—			$	—			$	—		$	—
	(a)	Included in Other within Current Liabilities on the Consolidated Balance Sheets.
	(b)	Included in Accrued pension and other post-retirement benefit costs on the Consolidated Balance Sheets.
Assumptions Used for Pension Benefits Accounting	The following tables present the assumptions used for other post-retirement benefits accounting.
			December 31,
			2014			2013			2012(a)
	Benefit Obligations
	Discount rate		4.1	%		4.7	%					4.1	%
	Net Periodic Benefit Cost
	Discount rate		4.7	%		4.1	%		4.6	%	-	5.1	%
	Expected long-term rate of return on plan assets		6.75	%		7.75	%		5	%	-	8	%
	Assumed tax rate		35	%		35	%					35	%
	(a)	For Progress Energy plans, the assumptions used in 2012 to determine net periodic post-retirement benefit costs reflect remeasurement as of July 1, 2012, due to the merger between Duke Energy and Progress Energy.
Assumed Health Care Cost Trend Rate	Assumed Health Care Cost Trend Rate
		December 31,
		2014			2013
	Health care cost trend rate assumed for next year	6.75	%		8.5	%
	Rate to which the cost trend is assumed to decline (the ultimate trend rate)	4.75	%		5	%
	Year that rate reaches ultimate trend	2023			2021
Sensitivity to Changes in Assumed Health Care Cost Trend Rates	Sensitivity to Changes in Assumed Health Care Cost Trend Rates
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	1-Percentage Point Increase
	Effect on total service and interest costs	$	2		$	1		$	1		$	—		$	1		$	—		$	—
	Effect on post-retirement benefit obligation	36			9			15			8			7			2			4
	1-Percentage Point Decrease
	Effect on total service and interest costs	(2		)	(1		)	(1		)	—			(1		)	—			—
	Effect on post-retirement benefit obligation	(31		)	(8		)	(13		)	(7		)	(6		)	(1		)	(3		)
Expected Benefit Payments	Expected Benefit Payments
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Years ending December 31,
	2015	$	77		$	17		$	30		$	16		$	14		$	4		$	10
	2016	77			18			30			16			14			4			10
	2017	76			18			29			15			14			3			9
	2018	74			19			29			15			14			3			9
	2019	73			19			29			15			13			3			8
	2020 - 2024	332			84			132			70			61			15			35

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Line Items]
Schedule of Components of Income Tax Expense (Benefit)	Components of Income Tax Expense
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Current income taxes
	Federal	$	—		$	161		$	(466	)	$	(184	)	$	(53	)	$	(73	)	$	(112	)
	State	56			51			(8		)	14			1			3			1
	Foreign	144			—			—			—			—			—			—
	Total current income taxes	200			212			(474		)	(170		)	(52		)	(70		)	(111		)
	Deferred income taxes
	Federal	1,517			407			938			436			350			113			294
	State	35			(25		)	84			25			52			1			15
	Foreign	(67		)	—			—			—			—			—			—
	Total deferred income taxes(a)(b)	1,485			382			1,022			461			402			114			309
	Investment tax credit amortization	(16		)	(6		)	(8		)	(6		)	(1		)	(1		)	(1		)
	Income tax expense from continuing operations	1,669			588			540			285			349			43			197
	Tax benefit from discontinued operations	(295		)	—			(4		)	—			—			(300		)	—
	Total income tax expense included in Consolidated Statements of Operations	$	1,374		$	588		$	536		$	285		$	349		$	(257	)	$	197
	(a)	There were no benefits of net operating loss (NOL) carryforwards.
	(b)	Includes utilization of NOL and tax credit carryforwards of $1,544 million at Duke Energy, $345 million at Duke Energy Carolinas, $530 million at Progress Energy, $291 million at Duke Energy Progress, $64 million at Duke Energy Florida, $56 million at Duke Energy Ohio and $141 million at Duke Energy Indiana.
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Current income taxes
	Federal	$	(141	)	$	49		$	(221	)	$	(70	)	$	(143	)	$	(24	)	$	(88	)
	State	(40		)	11			(37		)	(10		)	(13		)	(4		)	7
	Foreign	151			—			—			—			—			—			—
	Total current income taxes	(30		)	60			(258		)	(80		)	(156		)	(28		)	(81		)
	Deferred income taxes
	Federal	1,092			464			555			316			326			65			276
	State	144			75			84			59			44			6			29
	Foreign	14			—			—			—			—			—			—
	Total deferred income taxes(a)	1,250			539			639			375			370			71			305
	Investment tax credit amortization	(15		)	(5		)	(8		)	(7		)	(1		)	—			(1		)
	Income tax expense from continuing operations	1,205			594			373			288			213			43			223
	Tax expense from discontinued operations	29			—			(26		)	—			—			32			—
	Total income tax expense included in Consolidated Statements of Operations	$	1,234		$	594		$	347		$	288		$	213		$	75		$	223
	(a)	Includes benefits of NOL carryforwards of $808 million at Duke Energy, $458 million at Progress Energy, $64 million at Duke Energy Progress, $301 million at Duke Energy Florida and $179 million at Duke Energy Indiana.
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Current income taxes
	Federal	$	(108	)	$	(1	)	$	(88	)	$	(48	)	$	6		$	(8	)	$	(27	)
	State	29			(25		)	2			(6		)	—			5			27
	Foreign	133			—			—			—			—			—			—
	Total current income taxes	54			(26		)	(86		)	(54		)	6			(3		)	—
	Deferred income taxes
	Federal	491			408			226			162			121			40			(47		)
	State	71			77			40			9			21			(2		)	(25		)
	Foreign	20			—			—			—			—			—			—
	Total deferred income taxes(a)	582			485			266			171			142			38			(72		)
	Investment tax credit amortization	(13		)	(6		)	(8		)	(7		)	(1		)	(2		)	(1		)
	Income tax expense (benefit) from continuing operations	623			453			172			110			147			33			(73		)
	Tax benefit from discontinued operations	107			—			29			—			—			65			—
	Total income tax expense (benefit) included in Consolidated Statements of Operations	$	730		$	453		$	201		$	110		$	147		$	98		$	(73	)
	(a)	Includes benefits of NOL carryforwards of $1,062 million at Duke Energy, $245 million at Duke Energy Carolinas, $357 million at Progress Energy, $257 million at Duke Energy Progress, $25 million at Duke Energy Florida, $34 million at Duke Energy Ohio and $205 million at Duke Energy Indiana.
Schedule of Income before Income Tax, Domestic and Foreign	Duke Energy Income from Continuing Operations before Income Taxes
		Years Ended December 31,
	(in millions)	2014				2013				2012
	Domestic	$	3,600			$	3,183			$	1,600
	Foreign	534				612				634
	Income from continuing operations before income taxes	$	4,134			$	3,795			$	2,234
Summary of Effective Tax Rates	Statutory Rate Reconciliation
	The following tables present a reconciliation of income tax expense at the U.S. federal statutory tax rate to the actual tax expense from continuing operations.
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Income tax expense, computed at the statutory rate of 35 percent	$	1,447		$	581		$	497		$	263		$	314		$	39		$	195
	State income tax, net of federal income tax effect	59			17			49			25			34			3			10
	Tax differential on foreign earnings(a)	(110		)	—			—			—			—			—			—
	AFUDC equity income	(47		)	(32		)	(9		)	(9		)	—			(1		)	(5		)
	Renewable energy production tax credits	(67		)	—			—			—			—			—			—
	International tax dividend	373			—			—			—			—			—			—
	Other items, net	14			22			3			6			1			2			(3		)
	Income tax expense from continuing operations	$	1,669		$	588		$	540		$	285		$	349		$	43		$	197
	Effective tax rate	40.4		%	35.4		%	38		%	37.9		%	38.9		%	38.9		%	35.5		%
	(a)	Includes a $57 million benefit as a result of the merger of two Chilean subsidiaries and a change in income tax rates in various countries primarily relating to Peru.
	During the fourth quarter of 2014, Duke Energy declared a taxable dividend of foreign earnings in the form of notes payable that will result in the repatriation of approximately $2.7 billion of cash held and expected to be generated by International Energy over a period of up to 8 years. As a result of the decision to repatriate all cumulative historical undistributed foreign earnings, during the fourth quarter of 2014, Duke Energy recorded U.S. income tax expense of approximately $373 million. Duke Energy’s intention is to indefinitely reinvest prospective undistributed earnings generated by Duke Energy's foreign subsidiaries, and accordingly U.S. deferred taxes will not be provided for those earnings.
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Income tax expense, computed at the statutory rate of 35 percent	$	1,328		$	549		$	361		$	276		$	188		$	39		$	203
	State income tax, net of federal income tax effect	66			56			31			31			20			2			23
	Tax differential on foreign earnings	(49		)	—			—			—			—			—			—
	AFUDC equity income	(55		)	(32		)	(18		)	(15		)	(3		)	—			(5		)
	Renewable energy production tax credits	(62		)	—			—			—			—			—			—
	Other items, net	(23		)	21			(1		)	(4		)	8			2			2
	Income tax expense (benefit) from continuing operations	$	1,205		$	594		$	373		$	288		$	213		$	43		$	223
	Effective tax rate	31.8		%	37.8		%	36.2		%	36.5		%	39.6		%	39.1		%	38.4		%
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Income tax expense, computed at the statutory rate of 35 percent	$	782		$	461		$	185		$	134		$	145		$	27		$	(43	)
	State income tax, net of federal income tax effect	65			34			33			1			14			2			1
	Tax differential on foreign earnings	(69		)	—			—			—			—			—			—
	AFUDC equity income	(101		)	(54		)	(37		)	(24		)	(13		)	(2		)	(26		)
	Renewable energy production tax credits	(25		)	—			—			—			—			—			—
	Other items, net	(29		)	12			(9		)	(1		)	1			6			(5		)
	Income tax expense from continuing operations	$	623		$	453		$	172		$	110		$	147		$	33		$	(73	)
	Effective tax rate	27.9		%	34.3		%	32.7		%	28.7		%	35.7		%	42.9		%	59.5		%
Schedule of Deferred Tax Assets and Liabilities	DEFERRED TAXES
	Net Deferred Income Tax Liability Components
		December 31, 2014
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Deferred credits and other liabilities	$	188		$	53		$	108		$	28		$	78		$	(8	)	$	12
	Capital lease obligations	63			10			—			—			—			—			2
	Pension, postretirement and other employee benefits	546			4			188			96			93			17			43
	Progress Energy merger purchase accounting adjustments(a)	1,124			—			—			—			—			—			—
	Tax credits and NOL carryforwards	3,540			157			980			91			252			38			260
	Investments and other assets	—			—			—			—			—			14			—
	Other	—			12			—			55			—			35			11
	Valuation allowance	(184		)	—			(13		)	(1		)	—			—			—
	Total deferred income tax assets	5,277			236			1,263			269			423			96			328
	Investments and other assets	(1,625		)	(1,051		)	(427		)	(232		)	(245		)	—			(4		)
	Accelerated depreciation rates	(11,715		)	(4,046		)	(3,284		)	(2,030		)	(1,252		)	(1,660		)	(1,603		)
	Regulatory assets and deferred debits	(3,694		)	(953		)	(1,602		)	(809		)	(792		)	(141		)	(106		)
	Other	(44		)	—			(151		)	—			(246		)	—			—
	Total deferred income tax liabilities	(17,078		)	(6,050		)	(5,464		)	(3,071		)	(2,535		)	(1,801		)	(1,713		)
	Net deferred income tax liabilities	$	(11,801	)	$	(5,814	)	$	(4,201	)	$	(2,802	)	$	(2,112	)	$	(1,705	)	$	(1,385	)
	(a)	Primarily related to capital lease obligations and debt fair value adjustments.
		December 31, 2013
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy			Energy			Energy			Energy
					Carolinas						Progress			Florida			Ohio			Indiana
	Deferred credits and other liabilities	$	245		$	56		$	136		$	9		$	96		$	(13	)	$	9
	Capital lease obligations	59			11			—			—			—			—			(2		)
	Pension, postretirement and other employee benefits	649			18			341			119			145			23			54
	Progress Energy merger purchase accounting adjustments(a)	1,184			—			—			—			—			—			—
	Tax credits and NOL carryforwards	4,307			488			1,965			396			365			165			521
	Other	265			15			116			39			43			20			14
	Valuation allowance	(192		)	—			(40		)	(1		)	—			—			—
	Total deferred income tax assets	6,517			588			2,518			562			649			195			596
	Investments and other assets	(1,396		)	(999		)	(209		)	(160		)	(49		)	(17		)	(7		)
	Accelerated depreciation rates	(12,615		)	(4,400		)	(3,663		)	(2,528		)	(1,160		)	(1,937		)	(1,591		)
	Regulatory assets and deferred debits	(3,185		)	(609		)	(1,389		)	(202		)	(1,159		)	(168		)	(117		)
	Total deferred income tax liabilities	(17,196		)	(6,008		)	(5,261		)	(2,890		)	(2,368		)	(2,122		)	(1,715		)
	Net deferred income tax liabilities	$	(10,679	)	$	(5,420	)	$	(2,743	)	$	(2,328	)	$	(1,719	)	$	(1,927	)	$	(1,119	)
	(a)	Primarily related to capital lease obligations and debt fair value adjustments.
Summary of Tax Credit Carryforwards	The following table presents the expiration of tax credits and NOL carryforwards.
		December 31, 2014
	(in millions)	Amount				Expiration Year
	Investment tax credits	$	581			2029		—		2034
	Alternative minimum tax credits	1,093				Indefinite
	Federal NOL carryforwards	749				2030		—		2033
	State NOL carryforwards and credits(a)	162				2015		—		2034
	Foreign NOL carryforwards(b)	117				2015		—		2033
	Foreign Tax Credits	838				2024
	Total tax credits and NOL carryforwards	$	3,540
	(a)	A valuation allowance of $79 million has been recorded on the state Net Operating Loss carryforwards, as presented in the Net Deferred Income Tax Liability Components table.
	(b)	A valuation allowance of $105 million has been recorded on the foreign Net Operating Loss carryforwards, as presented in the Net Deferred Income Tax Liability Components table.
Schedule of Balance Sheet Classification of Deferred Tax Assets and Liabilities	Classification of Deferred Tax Assets (Liabilities) in the Consolidated Balance Sheets
		December 31, 2014
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy Progress			Energy Florida			Energy			Energy
					Carolinas												Ohio			Indiana
	Current Assets: Other	$	1,593		$	3		$	558		$	106		$	340		$	60		$	206
	Investments and Other Assets: Other	29			—			—			—			—			—			—
	Current Liabilities: Other	—			(5		)	—			—			—			—			—
	Deferred Credits and Other Liabilities: Other	(13,423		)	(5,812		)	(4,759		)	(2,908		)	(2,452		)	(1,765		)	(1,591		)
	Net deferred income tax liabilities	$	(11,801	)	$	(5,814	)	$	(4,201	)	$	(2,802	)	$	(2,112	)	$	(1,705	)	$	(1,385	)
		December 31, 2013
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy Progress			Energy Florida			Energy			Energy
					Carolinas												Ohio			Indiana
	Current Assets: Other	$	1,373		$	286		$	540		$	229		$	110		$	85		$	52
	Investments and Other Assets: Other	45			—			—			—			—			—			—
	Deferred Credits and Other Liabilities: Other	(12,097		)	(5,706		)	(3,283		)	(2,557		)	(1,829		)	(2,012		)	(1,171		)
	Net deferred income tax liabilities	$	(10,679	)	$	(5,420	)	$	(2,743	)	$	(2,328	)	$	(1,719	)	$	(1,927	)	$	(1,119	)
Schedule of Unrecognized Tax Benefits Roll Forward	The following tables present changes to unrecognized tax benefits.
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke
					Energy						Energy			Energy			Energy
					Carolinas						Progress			Florida			Indiana
	Unrecognized tax benefits — January 1	$	230		$	171		$	32		$	22		$	8		$	1
	Unrecognized tax benefits increases (decreases)
	Gross increases — tax positions in prior periods	—			—			1			1			—			—
	Gross decreases — tax positions in prior periods	(2		)	—			—			—			—			—
	Decreases due to settlements	(15		)	(11		)	(1		)	—			—			—
	Total changes	(17		)	(11		)	—			1			—			—
	Unrecognized tax benefits — December 31	$	213		$	160		$	32		$	23		$	8		$	1
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy Progress			Energy Florida			Energy			Energy
					Carolinas												Ohio			Indiana
	Unrecognized tax benefits — January 1	$	540		$	271		$	131		$	67		$	44		$	36		$	32
	Unrecognized tax benefits (decreases) increases
	Gross decreases — tax positions in prior periods	(231		)	(100		)	(86		)	(45		)	(37		)	(36		)	(31		)
	Decreases due to settlements	(66		)	—			—			—			—			—			—
	Reduction due to lapse of statute of limitations	(13		)	—			(13		)	—			1			—			—
	Total changes	(310		)	(100		)	(99		)	(45		)	(36		)	(36		)	(31		)
	Unrecognized tax benefits — December 31	$	230		$	171		$	32		$	22		$	8		$	—		$	1
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke			Progress Energy			Duke			Duke			Duke			Duke
					Energy						Energy Progress			Energy Florida			Energy			Energy
					Carolinas												Ohio			Indiana
	Unrecognized tax benefits — January 1	$	385		$	260		$	173		$	73		$	80		$	32		$	24
	Acquisitions	128			—			—			—			—			—			—
	Unrecognized tax benefits increases (decreases)
	Gross increases — tax positions in prior periods	29			12			23			10			12			2			6
	Gross decreases — tax positions in prior periods	(4		)	—			(72		)	(19		)	(52		)	—			—
	Gross increases — current period tax positions	28			15			8			4			4			4			4
	Gross decreases — current period tax positions	(9		)	(5		)	(1		)	(1		)	—			(2		)	(2		)
	Decreases due to settlements	(13		)	(11		)	—			—			—			—			—
	Reduction due to lapse of statute of limitations	(4		)	—			—			—			—			—			—
	Total changes	155			11			(42		)	(6		)	(36		)	4			8
	Unrecognized tax benefits — December 31	$	540		$	271		$	131		$	67		$	44		$	36		$	32
Schedule of Unrecognized Tax Benefits	The following table includes additional information regarding the Duke Energy Registrants' unrecognized tax benefits. It is reasonably possible that Duke Energy and Progress Energy will reflect an approximate $28 million reduction, Duke Energy Progress will reflect an approximate $17 million reduction, and Duke Energy Florida will reflect an approximate $7 million reduction in unrecognized tax benefits within the next 12 months due to the expected lapse of the statute of limitations. All other Duke Energy Registrants do not anticipate a material increase or decrease in unrecognized tax benefits within the next 12 months.
		December 31, 2014
	(in millions)	Duke			Duke			Progress Energy			Duke			Duke			Duke
		Energy			Energy						Energy Progress			Energy Florida			Energy
					Carolinas												Indiana
	Amount that if recognized, would affect the	$	121		$	112		$	3		$	2		$	2		$	2
	effective tax rate or regulatory liability(a)
	Amount that if recognized, would be recorded as a component	8			—			—			—			—			—
	of discontinued operations
	(a)	Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana are unable to estimate the specific amounts that would affect the effective tax rate versus the regulatory liability.
Summary of Income Tax Contingencies	The following tables include interest recognized in the Consolidated Statements of Operations and the Consolidated Balance Sheets.
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio			Duke Energy Indiana
	Net interest income recognized related to income taxes	$	6		$	—		$	3		$	—		$	1		$	4		$	4
	Net interest expense recognized related to income taxes	—			1			—			1			—			—			—
	Interest receivable related to income taxes	—			—			—			—			—			—			2
	Interest payable related to income taxes	13			13			5			3			5			—			—
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio		Duke Energy Indiana
	Net interest income recognized related to income taxes	$	2		$	2		6		7		—		4		$	1
	Interest payable related to income taxes	27			8			10		2		7		—		—
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy			Duke Energy Progress			Duke Energy Florida			Duke Energy Ohio		Duke Energy Indiana
	Net interest income recognized related to income taxes	$	10		$	9		$	—		$	—		$	—		—		2
	Net interest expense recognized related to income taxes	—			—			2			—			2			—		—
	Interest receivable related to income taxes	—			7			—			—			—			—		—
	Interest payable related to income taxes	7			—			17			8			9			3		1

Other_Income_and_Expenses_Net_

Other Income and Expenses, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Component Of Other Income Expense Nonoperating [Line Items]
Schedule of Other Income and Expenses, Net	The components of Other income and expenses, net on the Consolidated Statements of Operations are as follows.
		Year Ended December 31, 2014
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Interest income	$	57		$	4		$	3	$	—	$	2	$	8		$	6
	Foreign exchange gains	3			—			—		—		—		—			—
	AFUDC equity	135			91			26		25		—		4			14
	Deferred returns	89			71			17		17		—		—			—
	Other income (expense)	67			6			31		9		18		(2		)	2
	Other income and expense, net	$	351		$	172		$	77	$	51	$	20	$	10		$	22
		Year Ended December 31, 2013
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Interest income	$	26		$	1		$	7	$	1	$	3	$	5		$	6
	Foreign exchange losses	(18		)	—			—		—		—		—			—
	AFUDC equity	157			91			50		42		8		1			15
	Deferred returns	39			32			7		7		—		—			—
	Other income (expense)	58			(4		)	30		7		19		(4		)	(3		)
	Other income and expense, net	$	262		$	120		$	94	$	57	$	30	$	2		$	18
		Year Ended December 31, 2012
	(in millions)	Duke Energy			Duke Energy Carolinas			Progress Energy		Duke Energy Progress		Duke Energy Florida		Duke Energy Ohio			Duke Energy Indiana
	Interest income	$	50		$	11		$	2	$	1	$	1	$	—		$	7
	Foreign exchange gains	4			—			—		—		—		—			—
	AFUDC equity	300			154			106		69		37		6			84
	Deferred returns	24			24			—		—		—		—			—
	Other income (expense)	19			(4		)	22		9		1		2			(1		)
	Other income and expense, net	$	397		$	185		$	130	$	79	$	39	$	8		$	90

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Line Items]
Schedule Of Quarterly Financial Information	Quarterly EPS amounts are meant to be stand-alone calculations and are not always additive to the full-year amount due to rounding and the weighting of share issuances.
	(in millions, except per share data)	First			Second			Third			Fourth			Total
		Quarter(a)			Quarter(a)			Quarter(a)			Quarter(a)
	2014
	Operating revenues	$	6,263		$	5,708		$	6,395		$	5,559		$	23,925
	Operating income	1,362			1,289			1,619			988			5,258
	Income from continuing operations	750			725			891			99			2,465
	(Loss) income from discontinued operations, net of tax	(843		)	(112		)	378			1			(576		)
	Net loss (income)	(93		)	613			1,269			100			1,889
	Net loss (income) attributable to Duke Energy Corporation	(97		)	609			1,274			97			1,883
	Earnings per share:
	Income from continuing operations attributable to Duke Energy Corporation common shareholders
	Basic	$	1.05		$	1.02		$	1.25		$	0.14		$	3.46
	Diluted	$	1.05		$	1.02		$	1.25		$	0.14		$	3.46
	(Loss) income from discontinued operations attributable to Duke Energy Corporation common shareholders
	Basic	$	(1.19	)	$	(0.16	)	$	0.55		$	—		$	(0.80	)
	Diluted	$	(1.19	)	$	(0.16	)	$	0.55		$	—		$	(0.80	)
	Net (loss) income attributable to Duke Energy Corporation common shareholders
	Basic	$	(0.14	)	$	0.86		$	1.8		$	0.14		$	2.66
	Diluted	$	(0.14	)	$	0.86		$	1.8		$	0.14		$	2.66
	2013
	Operating revenues	$	5,536		$	5,393		$	6,217		$	5,610		$	22,756
	Operating income	1,259			742			1,660			1,193			4,854
	Income from continuing operations	663			292			946			689			2,590
	(Loss) income from discontinued operations, net of tax	(29		)	50			62			3			86
	Net income	634			342			1,008			692			2,676
	Net income attributable to Duke Energy Corporation	634			339			1,004			688			2,665
	Earnings per share:
	Income from continuing operations attributable to Duke Energy Corporation common shareholders
	Basic	$	0.93		$	0.4		$	1.33		$	0.96		$	3.64
	Diluted	$	0.93		$	0.4		$	1.33		$	0.96		$	3.63
	(Loss) income from discontinued operations attributable to Duke Energy Corporation common shareholders
	Basic	$	(0.04	)	$	0.08		$	0.09		$	0.01		$	0.13
	Diluted	$	(0.04	)	$	0.08		$	0.09		$	0.01		$	0.13
	Net income attributable to Duke Energy Corporation common shareholders
	Basic	$	0.89		$	0.48		$	1.42		$	0.97		$	3.77
	Diluted	$	0.89		$	0.48		$	1.42		$	0.97		$	3.76
	(a)	Operating results reflect reclassifications due to the impact of discontinued operations (see Note 2 for further information).
Schedule Of Unusual Or Infrequently Occurring Items	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve Progress Energy merger (see Note 2)	$	(55	)	$	(61	)	$	(56	)	$	(33	)	$	(205	)
	Midwest Generation Impairment (see Note 2)	(1,287		)	—			477			(39		)	(849		)
	Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(102		)	(102		)
	International Tax Adjustment (see Note 22)	—			—			—			(373		)	(373		)
	Asset Impairment (see Note 11)	(94		)	—			—			—			(94		)
	Total	$	(1,436	)	$	(61	)	$	421		$	(547	)	$	(1,623	)
	2013(a)
	Costs to achieve Progress Energy merger (see Note 2)	$	(55	)	$	(82	)	$	(88	)	$	(72	)	$	(297	)
	Crystal River Unit 3 charges (see Note 4)	—			(295		)	—			(57		)	(352		)
	Harris and Levy nuclear development charges (see Note 4)	—			(87		)	—			—			(87		)
	Gain on sale of DukeNet (see Note 12)	—			—			—			105			105
	Total	$	(55	)	$	(464	)	$	(88	)	$	(24	)	$	(631	)
	(a)	Revised retail rates became effective in January for Duke Energy Florida, May for Duke Energy Ohio, June for Duke Energy Progress and September for Duke Energy Carolinas (see Note 4 for further information).
Duke Energy Carolinas [Member]
Quarterly Financial Information Disclosure [Line Items]
Schedule Of Quarterly Financial Information	DUKE ENERGY CAROLINAS
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Operating revenues	$	2,000		$	1,755		$	1,938		$	1,658		$	7,351
	Operating income	509			438			630			318			1,895
	Net income	286			270			377			139			1,072
	2013
	Operating revenues	$	1,729		$	1,591		$	1,919		$	1,715		$	6,954
	Operating income	434			351			604			420			1,809
	Net income	244			181			342			209			976
Schedule Of Unusual Or Infrequently Occurring Items	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve Progress Energy merger (see Note 2)	$	(29	)	$	(38	)	$	(25	)	$	(17	)	$	(109	)
	Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(72		)	(72		)
	Total	(29		)	(38		)	(25		)	(89		)	(181		)
	2013(a)
	Costs to achieve Progress Energy merger (see Note 2)	$	(22	)	$	(35	)	$	(34	)	$	(29	)	$	(120	)
	(a)	Revised retail rates became effective in September in both North Carolina and South Carolina (see Note 4 for further information).
Progress Energy [Member]
Quarterly Financial Information Disclosure [Line Items]
Schedule Of Quarterly Financial Information	PROGRESS ENERGY
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Operating revenues	$	2,541		$	2,421		$	2,863		$	2,341		$	10,166
	Operating income	477			488			665			388			2,018
	Income from continuing operations	204			207			330			139			880
	Net income	203			202			330			139			874
	Net income attributable to Parent	202			202			329			136			869
	2013
	Operating revenues	$	2,186		$	2,281		$	2,766		$	2,300		$	9,533
	Operating income	430			114			671			403			1,618
	Income (loss) from continuing operations	154			(13		)	328			190			659
	Net income (loss)	154			(17		)	342			196			675
	Net income (loss) attributable to Parent	153			(17		)	341			195			672
Schedule Of Unusual Or Infrequently Occurring Items	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve the merger with Duke Energy (see Note 2)	$	(19	)	$	(12	)	$	(21	)	$	(13	)	$	(65	)
	Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(30		)	(30		)
	Total	(19		)	(12		)	(21		)	(43		)	(95		)
	2013(a)
	Costs to achieve the merger with Duke Energy (see Note 2)	$	(19	)	$	(33	)	$	(42	)	$	(28	)	$	(122	)
	Crystal River Unit 3 charges (see Note 4)	—			(295		)	—			(57		)	(352		)
	Harris and Levy nuclear development charges (see Note 4)	—			(87		)	—			—			(87		)
	Total	$	(19	)	$	(415	)	$	(42	)	$	(85	)	$	(561	)
	(a)	Revised retail rates became effective in January in Florida and June in North Carolina (see Note 4 for further information).
Duke Energy Progress [Member]
Quarterly Financial Information Disclosure [Line Items]
Schedule Of Quarterly Financial Information	DUKE ENERGY PROGRESS
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Operating revenues	$	1,422		$	1,191		$	1,367		$	1,196		$	5,176
	Operating income	258			212			285			180			935
	Net income	133			101			157			76			467
	2013
	Operating revenues	$	1,216		$	1,135		$	1,430		$	1,211		$	4,992
	Operating income	212			166			303			251			932
	Net income	110			77			175			138			500
Schedule Of Unusual Or Infrequently Occurring Items	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve the merger with Duke Energy (see Note 2)	$	(14	)	$	(3	)	$	(15	)	$	(10	)	$	(42	)
	Coal ash Plea Agreements Reserve (see Note 5)	—			—			—			(30		)	(30		)
	Total	(14		)	(3		)	(15		)	(40		)	(72		)
	2013(a)
	Costs to achieve the merger with Duke Energy (see Note 2)	$	(11	)	$	(22	)	$	(32	)	$	(19	)	$	(84	)
	Harris nuclear development charges (see Note 4)	$	—		$	(22	)	$	—		$	—		$	(22	)
	Total	$	(11	)	$	(44	)	$	(32	)	$	(19	)	$	(106	)
	(a)	Revised retail rates became effective in June in North Carolina (see Note 4 for further information).
Duke Energy Florida [Member]
Quarterly Financial Information Disclosure [Line Items]
Schedule Of Quarterly Financial Information	DUKE ENERGY FLORIDA
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Operating revenues	$	1,116		$	1,225		$	1,491		$	1,143		$	4,975
	Operating income	219			276			378			205			1,078
	Net income	108			142			205			93			548
	2013
	Operating revenues	$	968		$	1,142		$	1,332		$	1,085		$	4,527
	Operating income (loss)	221			(53		)	369			151			688
	Net income (loss)	110			(57		)	197			75			325
Schedule Of Unusual Or Infrequently Occurring Items	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve the merger with Duke Energy (see Note 2)	$	(5	)	$	(9	)	$	(6	)	$	(3	)	$	(23	)
	2013(a)
	Costs to achieve the merger with Duke Energy (see Note 2)	$	(8	)	$	(11	)	$	(10	)	$	(9	)	$	(38	)
	Crystal River Unit 3 charges (see Note 4)	—			(295		)	—			(57		)	(352		)
	Levy nuclear development charges (see Note 4)	—			(65		)	—			—			(65		)
	Total	$	(8	)	$	(371	)	$	(10	)	$	(66	)	$	(455	)
	(a)	Revised retail rates became effective in January (see Note 4 for further information).
Duke Energy Ohio [Member]
Quarterly Financial Information Disclosure [Line Items]
Schedule Of Quarterly Financial Information	DUKE ENERGY OHIO
	(in millions)	First			Second			Third			Fourth			Total
		Quarter(a)			Quarter(a)			Quarter(a)			Quarter(a)
	2014
	Operating revenues	$	575		$	412		$	446		$	480		$	1,913
	Operating (loss) income	(7		)	62			58			74			187
	(Loss) income from discontinued operations, net of tax	(875		)	(135		)	413			34			(563		)
	Net (loss) income	(890		)	(108		)	439			64			(495		)
	2013
	Operating revenues	$	503		$	408		$	438		$	456		$	1,805
	Operating income	56			27			50			49			182
	(Loss) income from discontinued operations, net of tax	(47		)	51			35			(4		)	35
	Net (loss) income	(21		)	58			59			6			102
	(a)	Operating results reflect reclassifications due to the impact of discontinued operations (see Note 2 for further information).
Schedule Of Unusual Or Infrequently Occurring Items	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve Progress Energy merger (see Note 2)	$	(2	)	$	(4	)	$	(3	)	$	(2	)	$	(11	)
	Midwest Generation Impairment (see Note 2)	(1,318		)	—			477			(39		)	(880		)
	Asset Impairment (see Note 11)	(94		)	—			—			—			(94		)
	Total	$	(1,414	)	$	(4	)	$	474		$	(41	)	$	(985	)
	2013(a)
	Costs to achieve Progress Energy merger (see Note 2)	$	(4	)	$	(4	)	$	(4	)	$	(4	)	$	(16	)
	(a)	Revised retail rates became effective in May (see Note 4 for further information).
Duke Energy Indiana [Member]
Quarterly Financial Information Disclosure [Line Items]
Schedule Of Quarterly Financial Information	DUKE ENERGY INDIANA
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Operating revenues	$	845		$	748		$	790		$	792		$	3,175
	Operating income	215			178			182			130			705
	Net income	113			87			101			58			359
	2013
	Operating revenues	$	724		$	700		$	755		$	747		$	2,926
	Operating income	181			168			203			181			733
	Net income	90			82			104			82			358
Schedule Of Unusual Or Infrequently Occurring Items	The following table includes unusual or infrequently occurring items in each quarter during the two most recently completed fiscal years. All amounts discussed below are pretax unless otherwise noted.
	(in millions)	First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	2014
	Costs to achieve Progress Energy merger (see Note 2)	$	(2	)	$	(5	)	$	(3	)	$	(2	)	$	(12	)
	2013
	Costs to achieve Progress Energy merger (see Note 2)	$	(4	)	$	(5	)	$	(5	)	$	(5	)	$	(19	)

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Narrative)(Details) (USD $)	12 Months Ended		1 Months Ended	12 Months Ended	96 Months Ended	6 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2022	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2011	Mar. 01, 2013
Organization And Basis Of Presentation [Line Items]
SAFSTOR Commencement Period	60 years
Preferred Stock Of Subsidiaries [Abstract]
Payments for the redemption of preferred stock		$96,000,000
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	2,036,000,000	1,501,000,000		1,424,000,000			2,036,000,000	2,110,000,000
Restricted Cash [Abstract]
Restricted cash	298,000,000	307,000,000					298,000,000
Duke Energy Carolinas [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	13,000,000	23,000,000		19,000,000			13,000,000	289,000,000
Progress Energy [Member]
Preferred Stock Of Subsidiaries [Abstract]
Payments for the redemption of preferred stock		96,000,000
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	42,000,000	58,000,000		231,000,000			42,000,000	230,000,000
Duke Energy Progress [Member]
Preferred Stock Of Subsidiaries [Abstract]
Payments for the redemption of preferred stock		62,000,000	62,000,000	0
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	9,000,000	21,000,000		18,000,000			9,000,000	20,000,000
Duke Energy Progress [Member] | Minimum [Member]
Preferred Stock Of Subsidiaries [Abstract]
Redemption price									$101
Duke Energy Progress [Member] | Maximum [Member]
Preferred Stock Of Subsidiaries [Abstract]
Redemption price									$110
Duke Energy Florida [Member]
Preferred Stock Of Subsidiaries [Abstract]
Payments for the redemption of preferred stock		34,000,000	34,000,000
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	8,000,000	16,000,000		131,000,000			8,000,000	16,000,000
Duke Energy Florida [Member] | Minimum [Member]
Preferred Stock Of Subsidiaries [Abstract]
Redemption price									$101
Duke Energy Florida [Member] | Maximum [Member]
Preferred Stock Of Subsidiaries [Abstract]
Redemption price									$104.25
Duke Energy Ohio [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	20,000,000	36,000,000		31,000,000			20,000,000	99,000,000
Duke Energy Indiana [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	6,000,000	15,000,000		36,000,000			6,000,000	16,000,000
International Energy [Member]
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents at end of period	1,680,000,000						1,680,000,000
Restricted Cash [Abstract]
Cash Repatriation period	8 years
International Energy [Member] | Scenario, Forecast [Member]
Cash and Cash Equivalents [Abstract]
Foreign Earnings Repatriated					$2,700,000,000
Utility Franchise Tax Member [Member] | Duke Energy Carolinas [Member] | State [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate						3.22%
Utility Franchise Tax Member [Member] | Duke Energy Progress [Member] | State [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate						3.22%
Electricity Sales Tax Member [Member] | Duke Energy Carolinas [Member] | State [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate						3.00%
Electricity Sales Tax Member [Member] | Duke Energy Progress [Member] | State [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate						3.00%
Current [Member] | Electricity Sales Tax Member [Member] | Duke Energy Carolinas [Member] | State [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate							7.00%
Current [Member] | Electricity Sales Tax Member [Member] | Duke Energy Progress [Member] | State [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate							7.00%

Summary_of_Significant_Account4

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Other Assets and Liabilities)(Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Organization And Basis Of Presentation [Line Items]
Collateral assets	$209	$135
Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	638	621
Duke Energy Carolinas [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	216	198
Collateral liabilities	128	120
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Collateral assets	23	10
Progress Energy [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Income taxes receivable	718	119
Progress Energy [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	174	214
Customer deposits	360	349
Derivative liabilities	271
Duke Energy Progress [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Income taxes receivable	272	15
Duke Energy Progress [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	116	121
Customer deposits	135	129
Derivative liabilities	108	38
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Collateral assets	23	10
Duke Energy Florida [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Income taxes receivable	177	65
Duke Energy Florida [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	57	65
Customer deposits	225	220
Derivative liabilities	163
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Collateral assets	186	125
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Collateral assets	13	122
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Income taxes receivable	98	56
Duke Energy Indiana [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	25	25
Collateral liabilities	$43	$40

Summary_of_Significant_Account5

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Amounts Attributable to Controlling Interests) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Organization And Basis Of Presentation [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$99	$891	$725	$750	$689	$946	$292	$663	$2,465	$2,590	$1,611
Income (Loss) from Continuing Operations Attributable to Noncontrolling Interest									14	16	18
Income from continuing operations attributable to Duke Energy common stockholders, as adjusted for participating securities - basic and diluted									2,451	2,574	1,593
Income (Loss) From Discontinued Operations, net of tax	1	378	-112	-843	3	62	50	-29	-576	86	171
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest									-8	-5	-4
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									-568	91	175
Net income	100	1,269	613	-93	692	1,008	342	634	1,889	2,676	1,782
Net Income (Loss) Attributable to Noncontrolling Interest									6	11	14
Net Income (Loss) Attributable to Parent	97	1,274	609	-97	688	1,004	339	634	1,883	2,665	1,768
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	139	330	207	204	190	328	-13	154	880	659	355
Income (Loss) from Continuing Operations Attributable to Noncontrolling Interest									5	3	7
Income from continuing operations attributable to Duke Energy common stockholders, as adjusted for participating securities - basic and diluted									875	656	348
Income (Loss) From Discontinued Operations, net of tax									-6	16	52
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									-6	16	52
Net income	139	330	202	203	196	342	-17	154	874	675	407
Net Income (Loss) Attributable to Noncontrolling Interest									5	3	7
Net Income (Loss) Attributable to Parent	$136	$329	$202	$202	$195	$341	($17)	$153	$869	$672	$400

Summary_of_Significant_Account6

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Inventory)(Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Public Utilities, Inventory [Line Items]
Materials and supplies	$2,102	$1,901
Coal held for electric generation	997	1,018
Oil, gas and other fuel held for electric generation	360	331
Public Utilities, Inventory	3,459	3,250
Duke Energy Carolinas [Member]
Public Utilities, Inventory [Line Items]
Materials and supplies	719	654
Coal held for electric generation	362	374
Oil, gas and other fuel held for electric generation	43	37
Public Utilities, Inventory	1,124	1,065
Progress Energy [Member]
Public Utilities, Inventory [Line Items]
Materials and supplies	981	854
Coal held for electric generation	329	334
Oil, gas and other fuel held for electric generation	280	236
Public Utilities, Inventory	1,590	1,424
Duke Energy Progress [Member]
Public Utilities, Inventory [Line Items]
Materials and supplies	676	567
Coal held for electric generation	150	187
Oil, gas and other fuel held for electric generation	140	99
Public Utilities, Inventory	966	853
Duke Energy Florida [Member]
Public Utilities, Inventory [Line Items]
Materials and supplies	305	287
Coal held for electric generation	178	147
Oil, gas and other fuel held for electric generation	140	137
Public Utilities, Inventory	623	571
Duke Energy Ohio [Member]
Public Utilities, Inventory [Line Items]
Materials and supplies	67	117
Coal held for electric generation	21	65
Oil, gas and other fuel held for electric generation	9	47
Public Utilities, Inventory	97	229
Duke Energy Indiana [Member]
Public Utilities, Inventory [Line Items]
Materials and supplies	258	193
Coal held for electric generation	275	238
Oil, gas and other fuel held for electric generation	4	3
Public Utilities, Inventory	$537	$434

Summary_of_Significant_Account7

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Property, Plant and Equipment)(Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Public Utility, Property, Plant and Equipment [Line Items]
Weighted-average depreciation rate	2.80%	2.80%	2.90%
Duke Energy Carolinas [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Weighted-average depreciation rate	2.70%	2.80%	2.80%
Progress Energy [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Weighted-average depreciation rate	2.50%	2.50%	2.60%
Duke Energy Progress [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Weighted-average depreciation rate	2.50%	2.50%	2.70%
Duke Energy Florida [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Weighted-average depreciation rate	2.70%	2.40%	2.50%
Duke Energy Ohio [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Weighted-average depreciation rate	2.30%	3.30%	3.20%
Duke Energy Indiana [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Weighted-average depreciation rate	3.00%	2.80%	3.30%

Summary_of_Significant_Account8

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Unbilled Revenues)(Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$827	$937
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	295	323
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	217	189
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	135	120
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	82	69
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables		55
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	27	5
Cinergy Receivables [Member] | Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	79	89
Cinergy Receivables [Member] | Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Unbilled receivables	$112	$144

Summary_of_Significant_Account9

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Allowance for Doubtful Accounts)(Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Organization And Basis Of Presentation [Line Items]
Receivables, allowance for doubtful accounts	$17	$30	$34
Restricted receivables, allowance for doubtful accounts	51	43	44
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Receivables, allowance for doubtful accounts	3	3	3
Restricted receivables, allowance for doubtful accounts	6	6	6
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Receivables, allowance for doubtful accounts	8	14	16
Restricted receivables, allowance for doubtful accounts	8
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Receivables, allowance for doubtful accounts	7	10	9
Restricted receivables, allowance for doubtful accounts	5
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Receivables, allowance for doubtful accounts	2	4	7
Restricted receivables, allowance for doubtful accounts	3
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Receivables, allowance for doubtful accounts	2	2	2
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Receivables, allowance for doubtful accounts	$1	$1	$1

Recovered_Sheet1

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Excise Taxes)(Details) (USD $)	12 Months Ended			6 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014	Dec. 31, 2014
Organization And Basis Of Presentation [Line Items]
Excise taxes	$498	$602	$466
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes	94	164	161
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes	263	304	317
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes	56	115	113
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes	207	189	205
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes	103	105	102
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes	38	29	33
State [Member] | Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Annual Reduction In Excise Taxes	160
State [Member] | Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Annual Reduction In Excise Taxes	$110
Utility Franchise Tax Member [Member] | State [Member] | Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate				3.22%
Utility Franchise Tax Member [Member] | State [Member] | Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate				3.22%
Electricity Sales Tax Member [Member] | State [Member] | Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate				3.00%
Electricity Sales Tax Member [Member] | State [Member] | Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate				3.00%
Electricity Sales Tax Member [Member] | Current [Member] | State [Member] | Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate					7.00%
Electricity Sales Tax Member [Member] | Current [Member] | State [Member] | Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Statutory Tax Rate					7.00%

Acquisitions_Dispositions_and_2

Acquisitions, Dispositions and Sales of Other Assets (Narrative) (Details) (USD $)	12 Months Ended			3 Months Ended	0 Months Ended	12 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2017	Jan. 12, 2012	Dec. 31, 2015	Dec. 31, 2012	Jul. 02, 2012	Jun. 30, 2015
Significant Acquisitions and Disposals [Line Items]
Payments to Acquire Businesses, Gross	$54,000,000		$451,000,000
Goodwill	16,321,000,000	16,340,000,000
Capital expenditures	5,384,000,000	5,526,000,000	5,501,000,000
Commercial Power [Member]
Significant Acquisitions and Disposals [Line Items]
Proceeds			187,000,000
Duke Energy Carolinas [Member]
Significant Acquisitions and Disposals [Line Items]
Capital expenditures	1,879,000,000	1,695,000,000	1,908,000,000
Progress Energy [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	3,655,000,000	3,655,000,000
Capital expenditures	1,940,000,000	2,490,000,000	2,366,000,000
Duke Energy Progress [Member]
Significant Acquisitions and Disposals [Line Items]
Capital expenditures	1,241,000,000	1,567,000,000	1,525,000,000
Duke Energy Florida [Member]
Significant Acquisitions and Disposals [Line Items]
Capital expenditures	699,000,000	915,000,000	809,000,000
Duke Energy Florida [Member] | Scenario, Forecast [Member]
Significant Acquisitions and Disposals [Line Items]
Payments to Acquire Businesses, Gross				166,000,000
Duke Energy Ohio [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	920,000,000	920,000,000
Capital expenditures	322,000,000	434,000,000	514,000,000
Transfer of Vermillion Generating Station			28,000,000		28,000,000
Duke Energy Indiana [Member]
Significant Acquisitions and Disposals [Line Items]
Capital expenditures	625,000,000	545,000,000	718,000,000
Transfer of Vermillion Generating Station			26,000,000		26,000,000
NCEMPA Generating Assets [Member] | Duke Energy Progress [Member] | Scenario, Forecast [Member]
Significant Acquisitions and Disposals [Line Items]
Payments to Acquire Businesses, Gross						1,200,000,000
Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Business combination, pro forma information, revenue of acquiree since acquisition date, actual			4,943,000,000
Business combination, pro forma information, earnings or loss of acquiree since acquisition date, actual			368,000,000
Property, plant and equipment								23,141,000,000
Goodwill								12,469,000,000
Working capital								3,204,000,000
Ibener [Member]
Significant Acquisitions and Disposals [Line Items]
Payments to Acquire Businesses, Gross							415,000,000
Property, plant and equipment			383,000,000				383,000,000
Intangibles			30,000,000				30,000,000
Deferred tax			57,000,000				57,000,000
Goodwill			54,000,000				54,000,000
Working capital			8,000,000				8,000,000
Duke Energy Vermillion [Member] | Duke Energy Ohio [Member]
Significant Acquisitions and Disposals [Line Items]
Proceeds					82,000,000
Duke Energy Vermillion [Member] | Duke Energy Indiana [Member]
Significant Acquisitions and Disposals [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share					62.50%
Capital expenditures					68,000,000
Midwest Generation Business [Member] | Duke Energy Ohio [Member] | Scenario, Forecast [Member]
Significant Acquisitions and Disposals [Line Items]
Disposal Group, Including Discontinued Operation, Consideration									$2,800,000,000

Acquisitions_Dispositions_and_3

Acquisitions, Dispositions and Sales of Other Assets (Purchase Price Calculation) (Details) (USD $)	0 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 02, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Significant Acquisitions and Disposals [Line Items]
Progress Energy common shares outstanding		707,000,000	706,000,000	445,000,000
Exchange ratio	87.08%
Duke Energy common shares issued for Progress Energy common shares outstanding	257,867,000
Closing price of Duke Energy common shares	$69.84
Purchase price for common shares	$18,009
Fair value of outstanding earned stock compensation awards	62
Total estimate purchase price	$18,071
Progress Energy [Member]
Significant Acquisitions and Disposals [Line Items]
Progress Energy common shares outstanding	296,116,000	100	100

Acquisitions_Dispositions_and_4

Acquisitions, Dispositions and Sales of Other Assets (Accounting Charges) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Significant Acquisitions and Disposals [Line Items]
FERC mitigation	($15)		$117
Severance charges		34	201
Community support and charitable contributions and other		34	92
Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
FERC mitigation			117
Severance charges			196
Community support and charitable contributions and other			169
Total charges related to the merger consummation			482
Duke Energy Carolinas [Member]
Significant Acquisitions and Disposals [Line Items]
FERC mitigation	3		46
Severance charges		8	63
Community support and charitable contributions and other		14	56
Duke Energy Carolinas [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
FERC mitigation			46
Severance charges			63
Community support and charitable contributions and other			79
Total charges related to the merger consummation			188
Progress Energy [Member]
Significant Acquisitions and Disposals [Line Items]
FERC mitigation	-18		71
Severance charges		19	82
Community support and charitable contributions and other		20	36
Progress Energy [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
FERC mitigation			71
Severance charges			82
Community support and charitable contributions and other			74
Total charges related to the merger consummation			227
Duke Energy Progress [Member]
Significant Acquisitions and Disposals [Line Items]
FERC mitigation	-18		71
Severance charges		14	55
Community support and charitable contributions and other		20	36
Duke Energy Progress [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
FERC mitigation			71
Severance charges			55
Community support and charitable contributions and other			63
Total charges related to the merger consummation			189
Duke Energy Florida [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges		5	27
Duke Energy Florida [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			27
Community support and charitable contributions and other			11
Total charges related to the merger consummation			38
Duke Energy Ohio [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges		2	21
Duke Energy Ohio [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			21
Community support and charitable contributions and other			7
Total charges related to the merger consummation			28
Duke Energy Indiana [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges		2	18
Duke Energy Indiana [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			18
Community support and charitable contributions and other			6
Total charges related to the merger consummation			$24

Acquisitions_Dispositions_and_5

Acquisitions, Dispositions and Sales of Other Assets (Purchase Price Allocation) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jul. 02, 2012
In Millions, unless otherwise specified
Significant Acquisitions and Disposals [Line Items]
Goodwill	$16,321	$16,340
Total purchase price			18,071
Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Current assets			3,204
Property, plant and equipment			23,141
Goodwill			12,469
Other long-term assets, excluding goodwill			9,990
Total assets			48,804
Current liabilities, including current maturities of long-term debt			3,593
Long-term liabilities, preferred stock and noncontrolling interests			10,394
Long-term debt			16,746
Total liabilities and preferred stock			30,733
Total purchase price			$18,071

Acquisitions_Dispositions_and_6

Acquisitions, Dispositions and Sales of Other Assets (Narrative - Change in PPA) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jul. 02, 2012
In Millions, unless otherwise specified
Significant Acquisitions and Disposals [Line Items]
Goodwill	$16,321	$16,340
Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Current assets			3,204
Property, plant and equipment			-23,141
Goodwill			12,469
Other long-term assets, excluding goodwill			-9,990
Current liabilities, including current maturities of long-term debt			3,593
Long-term liabilities, preferred stock and noncontrolling interests			-10,394
Purchase Price Allocation Adjustment [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Property, plant and equipment		138
Goodwill		2
Other long-term assets, excluding goodwill		4
Current liabilities, including current maturities of long-term debt		12
Long-term liabilities, preferred stock and noncontrolling interests		$152

Acquisitions_Dispositions_and_7

Acquisitions, Dispositions and Sales of Other Assets (Pro Forma Financial Information) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Costs to achieve the merger	$33	$56	$61	$55	$72	$88	$82	$55	$205	$297
Revenues											23,976
Net Income Attributable to Duke Energy Corporation											2,417
Pro Forma Basic and Diluted Earnings Per Share											$3.43
Excluded From Pro Forma [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Costs to achieve the merger											$413

Acquisitions_Dispositions_and_8

Acquisitions, Dispositions and Sales of Other Assets Acquisitions, Dispositions and Sales of Other Assets (Plants in Disposal Group) (Details) (Duke Energy Ohio [Member])	12 Months Ended
	Dec. 31, 2014
	MW
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	9,225
Owned Plant Capacity	5,884
J M Stuart Station [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	2,308
Owned Plant Capacity	900
Jointly Owned Utility Plant, Proportionate Ownership Share	39.00%
W M Zimmer Station [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	1,300
Owned Plant Capacity	605
Jointly Owned Utility Plant, Proportionate Ownership Share	46.50%
Hanging Rock [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	1,226
Owned Plant Capacity	1,226
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%
Miami Fort Station Units 7 And 8 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	1,020
Owned Plant Capacity	652
Jointly Owned Utility Plant, Proportionate Ownership Share	64.00%
Conesville Station (Unit 4) [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	780
Owned Plant Capacity	312
Jointly Owned Utility Plant, Proportionate Ownership Share	40.00%
Washington [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	617
Owned Plant Capacity	617
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%
Fayette [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	614
Owned Plant Capacity	614
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%
Killen Station [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	600
Owned Plant Capacity	198
Jointly Owned Utility Plant, Proportionate Ownership Share	33.00%
Lee [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	568
Owned Plant Capacity	568
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%
Dicks Creek [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	136
Owned Plant Capacity	136
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%
Miami Fort [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Plant Capacity	56
Owned Plant Capacity	56
Jointly Owned Utility Plant, Proportionate Ownership Share	100.00%

Acquisitions_Dispositions_and_9

Acquisitions, Dispositions and Sales of Other Assets Acquisitions, Dispositions and Sales of Other Assets (Assets Held For Sale) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income tax (benefit) expense									($295)	$29	$107
Income (Loss) From Discontinued Operations, net of tax	1	378	-112	-843	3	62	50	-29	-576	86	171
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Current assets	364								364
Current liabilities	262				7				262	7
Midwest Generation Business [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Operating Revenues									1,748	1,885	1,771
Estimated loss on disposition									-929
(Loss) Income before income taxes									-818	141	227
Income tax (benefit) expense									-294	56	82
Income (Loss) From Discontinued Operations, net of tax									-524	85	145
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Current assets	364								364
Investments and other assets	52								52
Property, plant and equipment	2,590								2,590
Total assets held for sale	3,006								3,006
Current liabilities	262								262
Deferred credits and other liabilities	35								35
Total liabilities associated with assets held for sale	297								297
Other Disposal Groups [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income (Loss) From Discontinued Operations, net of tax									-52	1	26
Duke Energy Ohio [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income tax (benefit) expense									-300	32	65
Income (Loss) From Discontinued Operations, net of tax	34	413	-135	-875	-4	35	51	-47	-563	35	130
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Current assets	316								316
Current liabilities	246								246
Duke Energy Ohio [Member] | Midwest Generation Business [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Operating Revenues									1,299	1,503	1,435
Estimated loss on disposition									-959
(Loss) Income before income taxes									-863	67	195
Income tax (benefit) expense									-300	32	65
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Current assets	316								316
Investments and other assets	46								46
Property, plant and equipment	2,559								2,559
Total assets held for sale	2,921								2,921
Current liabilities	246								246
Deferred credits and other liabilities	34								34
Total liabilities associated with assets held for sale	$280								$280

Business_Segments_Narrative_De

Business Segments (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Interest expense	$1,622	$1,543	$1,244
Duke Energy Carolinas [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	1
Interest expense	407	359	384
Progress Energy [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	1
Interest expense	675	680	740
Duke Energy Progress [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	1
Interest expense	234	201	207
Duke Energy Progress [Member] | North Carolina Electric Membership Corporation [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue, major customer, percentage	11.00%
Duke Energy Florida [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	1
Interest expense	201	180	255
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Interest expense	86	74	89
Duke Energy Indiana [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	1
Interest expense	171	170	138
Other Segment [Member] | Progress Energy [Member]
Segment Reporting Information [Line Items]
Interest expense	$241	$300	$304
National Methanol Company [Member] | International Energy [Member]
Segment Reporting Information [Line Items]
Equity method investment, ownership percentage	25.00%

Business_Segments_Business_Seg

Business Segments (Business Segment Data) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	$5,559	$6,395	$5,708	$6,263	$5,610	$6,217	$5,393	$5,536	$23,925	$22,756	$17,912
Interest expense									1,622	1,543	1,244
Depreciation and amortization									3,066	2,668	2,145
Equity in earnings (losses) of unconsolidated affiliates									130	122	148
Income tax expense (benefit) from continuing operations									1,669	1,205	623
Segment income									2,451	2,574	1,593
Add back noncontrolling interests component									14	16	18
Income (Loss) From Discontinued Operations, net of tax	1	378	-112	-843	3	62	50	-29	-576	86	171
Net Income (Loss) Attributable to Parent	97	1,274	609	-97	688	1,004	339	634	1,883	2,665	1,768
Net income (loss)	100	1,269	613	-93	692	1,008	342	634	1,889	2,676	1,782
Impairment charges									81	399	666
Deferred foreign taxes									-67	14	20
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									5,528	5,607	5,958
Assets	120,709				114,779				120,709	114,779	113,856
Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	480	446	412	575	456	438	408	503	1,913	1,805	1,820
Interest expense									86	74	89
Depreciation and amortization									214	213	195
Income tax expense (benefit) from continuing operations									43	43	33
Segment income									68	67	45
Income (Loss) From Discontinued Operations, net of tax	34	413	-135	-875	-4	35	51	-47	-563	35	130
Net Income (Loss) Attributable to Parent									-495	102	175
Net income (loss)	64	439	-108	-890	6	59	58	-21	-495	102	175
Impairment charges									94	5	2
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									322	433	514
Assets	9,999				10,763				9,999	10,763	10,560
Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									-123	-135	-108
Interest expense									-22	-6
Segment income									-10	-12	-8
Segment Reporting Information Assets [Abstract]
Assets	189				188				189	188	170
Intersegment Eliminations [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									-1		-2
Segment Reporting Information Assets [Abstract]
Assets	-230				-155				-230	-155	-166
Other VIEs [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Impairment charges									94
Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									22,228	20,871	16,042
Equity in earnings (losses) of unconsolidated affiliates									-3	-1	-5
After tax deferral of voluntary severance charge											60
Regulated Utilities [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,894	1,765	1,745
Regulated Utilities [Member] | Operating Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									22,271	20,910	16,080
Interest expense									1,093	986	806
Depreciation and amortization									2,759	2,323	1,827
Equity in earnings (losses) of unconsolidated affiliates										-1	-5
Income tax expense (benefit) from continuing operations									1,628	1,522	942
Segment income									2,795	2,504	1,744
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									4,744	5,049	4,220
Assets	106,657				99,884				106,657	99,884	98,162
Regulated Utilities [Member] | Operating Segments [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,895	1,765	1,746
Interest expense									81	74	61
Depreciation and amortization									211	200	179
Income tax expense (benefit) from continuing operations									117	91	91
Segment income									202	151	159
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									300	375	427
Assets	6,908				6,649				6,908	6,649	6,434
Regulated Utilities [Member] | Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									-43	-39	-38
Regulated Utilities [Member] | Intersegment Eliminations [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									-1		-1
International Energy [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,417	1,546	1,549
Equity in earnings (losses) of unconsolidated affiliates									120	110	134
Deferred foreign taxes									373
International Energy [Member] | Operating Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,417	1,546	1,549
Interest expense									93	86	77
Depreciation and amortization									97	100	99
Equity in earnings (losses) of unconsolidated affiliates										110	134
Income tax expense (benefit) from continuing operations									449	166	149
Segment income									55	408	439
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									67	67	551
Assets	5,132				4,998				5,132	4,998	5,406
Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									255	254	299
Equity in earnings (losses) of unconsolidated affiliates									10	7	14
Commercial Power [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									19	40	75
Commercial Power [Member] | Operating Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									255	260	307
Interest expense									58	61	63
Depreciation and amortization									92	110	85
Equity in earnings (losses) of unconsolidated affiliates										7	14
Income tax expense (benefit) from continuing operations									-171	-148	-82
Segment income									-55	-88	-59
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									555	268	1,038
Assets	6,278				6,955				6,278	6,955	6,992
Commercial Power [Member] | Operating Segments [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									19	40	76
Interest expense									5		28
Depreciation and amortization									2	13	16
Income tax expense (benefit) from continuing operations									-67	-36	-40
Segment income									-121	-65	-80
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									22	58	87
Assets	3,187				4,170				3,187	4,170	4,175
Commercial Power [Member] | Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues										-6	-8
Commercial Power [Member] | Intersegment Eliminations [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues											-1
Commercial Power [Member] | Other VIEs [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Impairment charges									94
Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									23,900	22,671	17,890
Segment income									2,795	2,824	2,124
Total Reportable Segments [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,913	1,805	1,820
Total Reportable Segments [Member] | Operating Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									23,943	22,716	17,936
Interest expense									1,244	1,133	946
Depreciation and amortization									2,948	2,533	2,011
Equity in earnings (losses) of unconsolidated affiliates									127	116	143
Income tax expense (benefit) from continuing operations									1,906	1,540	1,009
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									5,366	5,384	5,809
Assets	118,067				111,837				118,067	111,837	110,560
Total Reportable Segments [Member] | Operating Segments [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,914	1,805	1,822
Interest expense									86	74	89
Depreciation and amortization									213	213	195
Income tax expense (benefit) from continuing operations									50	55	51
Segment income									81	86	79
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									322	433	514
Assets	10,095				10,819				10,095	10,819	10,609
Total Reportable Segments [Member] | Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									-43	-45	-46
Total Reportable Segments [Member] | Intersegment Eliminations [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									-1		-2
Other Segment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									25	85	22
Other Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									-80	-90	-62
Other Segment [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									105	175	84
Interest expense									400	416	298
Depreciation and amortization									118	135	134
Equity in earnings (losses) of unconsolidated affiliates										6	5
Income tax expense (benefit) from continuing operations									-237	-335	-386
Segment income									-334	-238	-523
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									162	223	149
Assets	2,453				2,754				2,453	2,754	3,126
Other Segment [Member] | Corporate, Non-Segment [Member] | Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Depreciation and amortization									1
Income tax expense (benefit) from continuing operations									-7	-12	-18
Segment income									-13	-19	-34
Segment Reporting Information Assets [Abstract]
Assets	$134				$99				$134	$99	$117

Business_Segments_Schedule_of_

Business Segments (Schedule of Revenue and Long-Lived Assets, By Geographical Area) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenue	$5,559	$6,395	$5,708	$6,263	$5,610	$6,217	$5,393	$5,536	$23,925	$22,756	$17,912
Consolidated long-lived assets	83,167				81,362				83,167	81,362	81,611
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenue									22,508	21,211	16,366
Consolidated long-lived assets	80,709				78,581				80,709	78,581	79,144
Latin America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated revenue									1,417	1,545	1,546
Consolidated long-lived assets	$2,458				$2,781				$2,458	$2,781	$2,467

Business_Segments_Schedule_of_1

Business Segments (Schedule of Revenue, By Products and Services) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Operating revenues	$5,559	$6,395	$5,708	$6,263	$5,610	$6,217	$5,393	$5,536	$23,925	$22,756	$17,912
Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues									22,228	20,871	16,042
International Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues									1,417	1,546	1,549
Commercial Power [Member]
Segment Reporting Information [Line Items]
Operating revenues									255	254	299
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues									23,900	22,671	17,890
Retail Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues									19,007	17,837	13,773
Retail Electric [Member] | Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues									19,007	17,837	13,773
Wholesale Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues									3,460	3,427	2,871
Wholesale Electric [Member] | Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues									1,879	1,720	1,120
Wholesale Electric [Member] | International Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues									1,326	1,447	1,444
Wholesale Electric [Member] | Commercial Power [Member]
Segment Reporting Information [Line Items]
Operating revenues									255	260	307
Retail Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues									571	506	470
Retail Gas [Member] | Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues									571	506	470
Wholesale Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues									91	99	105
Wholesale Gas [Member] | International Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues									91	99	105
Other Revenues [Member]
Segment Reporting Information [Line Items]
Operating revenues									814	847	717
Other Revenues [Member] | Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues									814	847	717
Operating Segments [Member] | Regulated Utilities [Member]
Segment Reporting Information [Line Items]
Operating revenues									22,271	20,910	16,080
Operating Segments [Member] | International Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues									1,417	1,546	1,549
Operating Segments [Member] | Commercial Power [Member]
Segment Reporting Information [Line Items]
Operating revenues									255	260	307
Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues									$23,943	$22,716	$17,936

Business_Segments_Net_Loss_Det

Business Segments (Net Loss) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Segment income	$2,451	$2,574	$1,593
Duke Energy Carolinas [Member] | Other Segment [Member]
Segment Reporting Information [Line Items]
Segment income	-79	-97	-169
Progress Energy [Member]
Segment Reporting Information [Line Items]
Segment income	875	656	348
Progress Energy [Member] | Other Segment [Member]
Segment Reporting Information [Line Items]
Segment income	-190	-241	-379
Duke Energy Progress [Member] | Other Segment [Member]
Segment Reporting Information [Line Items]
Segment income	-31	-46	-139
Duke Energy Florida [Member] | Other Segment [Member]
Segment Reporting Information [Line Items]
Segment income	-19	-24	-58
Duke Energy Indiana [Member] | Other Segment [Member]
Segment Reporting Information [Line Items]
Segment income	($11)	($16)	($27)

Regulatory_Matters_Narrative_D

Regulatory Matters (Narrative) (Details) (USD $)	12 Months Ended			36 Months Ended	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Mar. 31, 2017
Public Utilities, General Disclosures [Line Items]
Restructuring Reserve	$28,000,000	$64,000,000		$28,000,000
Net property, plant and equipment	70,046,000,000	69,490,000,000		70,046,000,000
Regulatory assets, current	1,115,000,000	895,000,000		1,115,000,000
Net Asset Percentage Limit	25.00%			25.00%
Payments to Acquire Businesses, Gross	54,000,000		451,000,000
Capitalized interest	75,000,000	89,000,000	176,000,000
Impairment charges	81,000,000	399,000,000	666,000,000
Regulatory assets, noncurrent	11,042,000,000	9,191,000,000		11,042,000,000
Regulatory liability, noncurrent	6,193,000,000	5,949,000,000		6,193,000,000
Regulatory assets	12,157,000,000	10,086,000,000		12,157,000,000
Capital expenditures	5,384,000,000	5,526,000,000	5,501,000,000
Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	1,659,000,000	1,748,000,000		1,659,000,000
Nuclear Deferral [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	296,000,000	262,000,000		296,000,000
Atlantic Coast Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	40.00%			40.00%
NCEMC [Member] | William States Lee Combined Cycle Facility [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	13.00%			13.00%
Duke Energy Kentucky [Member]
Public Utilities, General Disclosures [Line Items]
Required Equity Capital Structure Percent	35.00%			35.00%
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Restructuring Reserve	2,000,000	5,000,000		2,000,000
Net property, plant and equipment	24,672,000,000	23,012,000,000		24,672,000,000
Regulatory assets, current	399,000,000	295,000,000		399,000,000
Capitalized interest	38,000,000	41,000,000	72,000,000
Impairment charges	3,000,000		31,000,000
Regulatory assets, noncurrent	2,465,000,000	1,527,000,000		2,465,000,000
Regulatory liability, noncurrent	2,710,000,000	2,576,000,000		2,710,000,000
Regulatory assets	2,864,000,000	1,822,000,000		2,864,000,000
Capital expenditures	1,879,000,000	1,695,000,000	1,908,000,000
Duke Energy Carolinas [Member] | Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	58,000,000	68,000,000		58,000,000
Duke Energy Carolinas [Member] | Nuclear Deferral [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	141,000,000	40,000,000		141,000,000
Duke Energy Carolinas [Member] | Minimum [Member] | Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Noncurrent Asset, Amortization Period	5 years
Duke Energy Carolinas [Member] | Maximum [Member] | Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Noncurrent Asset, Amortization Period	10 years
Duke Energy Carolinas [Member] | Rate Case Step One [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	204,000,000
Approved percentage rate increase by state commission	4.50%
Duke Energy Carolinas [Member] | Rate Case Step One [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	80,000,000
Approved percentage rate increase by state commission	5.50%
Duke Energy Carolinas [Member] | Rate Case Step Two [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	30,000,000
Approved percentage rate increase by state commission	0.60%
Duke Energy Carolinas [Member] | Rate Case Step Two [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	38,000,000
Approved percentage rate increase by state commission	2.60%
Duke Energy Carolinas [Member] | Rate Case [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	10.20%
Approved equity capital structure, percentage	53.00%
Required shareholder contribution to low income customers or agencies.	10,000,000
Rate increase begin date	25-Sep-13
Duke Energy Carolinas [Member] | Rate Case [Member] | NCUC [Member] | Removal Costs Reduction Year One [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory liability, noncurrent	30,000,000			30,000,000
Duke Energy Carolinas [Member] | Rate Case [Member] | NCUC [Member] | Removal Costs Reduction Year Two [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory liability, noncurrent	30,000,000			30,000,000
Duke Energy Carolinas [Member] | Rate Case [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	10.20%
Approved equity capital structure, percentage	53.00%
Required shareholder contribution to low income customers or agencies.	4,000,000
Rate increase begin date	18-Sep-13
Duke Energy Carolinas [Member] | Rate Case [Member] | PSCSC [Member] | Removal Costs Reduction Year One [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory liability, noncurrent	45,000,000			45,000,000
Duke Energy Carolinas [Member] | William State Lee III Nuclear Station [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	427,000,000			427,000,000
Duke Energy Carolinas [Member] | NCEMC [Member] | William States Lee Combined Cycle Facility [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC	600,000,000			600,000,000
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Restructuring Reserve	1,000,000	11,000,000		1,000,000
Net property, plant and equipment	15,186,000,000	13,650,000,000		15,186,000,000
Regulatory assets, current	287,000,000	127,000,000		287,000,000
Capitalized interest	10,000,000	16,000,000	23,000,000
Impairment charges	-18,000,000	22,000,000	54,000,000
Regulatory assets, noncurrent	2,675,000,000	1,384,000,000		2,675,000,000
Regulatory liability, noncurrent	1,832,000,000	1,673,000,000		1,832,000,000
Regulatory assets	2,962,000,000	1,511,000,000		2,962,000,000
Capital expenditures	1,241,000,000	1,567,000,000	1,525,000,000
Duke Energy Progress [Member] | Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Noncurrent Asset, Amortization Period	10 years
Regulatory assets	152,000,000	241,000,000		152,000,000
Duke Energy Progress [Member] | Nuclear Deferral [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	43,000,000	77,000,000		43,000,000
Duke Energy Progress [Member] | Maximum [Member] | Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Noncurrent Asset, Amortization Period	10 years
Duke Energy Progress [Member] | FERC Mitigation [Member]
Public Utilities, General Disclosures [Line Items]
Impairment charges	-18,000,000
Duke Energy Progress [Member] | Rate Case Step One [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	147,000,000
Approved percentage rate increase by state commission	4.50%
Duke Energy Progress [Member] | Rate Case Step Two [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	31,000,000
Approved percentage rate increase by state commission	1.00%
Duke Energy Progress [Member] | Rate Case [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	10.20%
Approved equity capital structure, percentage	53.00%
Required shareholder contribution to low income customers or agencies.	20,000,000
Rate increase begin date	1-Jun-13
Duke Energy Progress [Member] | Rate Case [Member] | NCUC [Member] | Removal Costs Reduction Year One [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory liability, noncurrent	20,000,000			20,000,000
Duke Energy Progress [Member] | Shearon Harris Nuclear Station [Member]
Public Utilities, General Disclosures [Line Items]
Impairment charges	22,000,000
Regulatory assets, noncurrent	48,000,000			48,000,000
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Restructuring Reserve	17,000,000	24,000,000		17,000,000
Net property, plant and equipment	9,955,000,000	9,611,000,000		9,955,000,000
Regulatory assets, current	203,000,000	221,000,000		203,000,000
Capitalized interest	1,000,000	3,000,000	18,000,000
Impairment charges	2,000,000	358,000,000	146,000,000
Regulatory assets, noncurrent	2,733,000,000	2,729,000,000		2,733,000,000
Regulatory liability, noncurrent	547,000,000	618,000,000		547,000,000
Regulatory assets	2,936,000,000	2,950,000,000		2,936,000,000
Capital expenditures	699,000,000	915,000,000	809,000,000
Duke Energy Florida [Member] | Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Noncurrent Asset, Amortization Period	20 years
Regulatory assets	1,393,000,000	1,378,000,000		1,393,000,000
Duke Energy Florida [Member] | Nuclear Deferral [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	112,000,000	145,000,000		112,000,000
Duke Energy Florida [Member] | FPSC [Member] | Removal Costs [Member]
Public Utilities, General Disclosures [Line Items]
Amount of reduction to carrying amount of regulatory liabilities		114,000,000	178,000,000
Duke Energy Florida [Member] | FERC Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	10.80%
Duke Energy Florida [Member] | FERC Complaint 1 [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	9.02%
Duke Energy Florida [Member] | FERC Complaint 2 [Member] | Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	8.63%
Duke Energy Florida [Member] | FERC Complaint 2 [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	8.84%
Duke Energy Florida [Member] | FERC Complaint 3 [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	8.69%
Duke Energy Florida [Member] | 2013 FPSC Settlement Agreement [Member] | New Generation Needs [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	10.50%
Duke Energy Florida [Member] | 2013 FPSC Settlement Agreement [Member] | Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	9.50%
Duke Energy Florida [Member] | 2013 FPSC Settlement Agreement [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	11.50%
Duke Energy Florida [Member] | 2012 FPSC Settlement Agreement [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets, current	50,000,000			50,000,000
Approved rate increase amount by state commission	150,000,000
Customer Refund Liability, Current	120,000,000			120,000,000
Total Customer Refunds To Be Paid	388,000,000
Regulatory liability, noncurrent	70,000,000			70,000,000
Duke Energy Florida [Member] | Crystal River Unit 3 [Member]
Public Utilities, General Disclosures [Line Items]
Decommissioning cost study estimate	1,180,000,000			1,180,000,000
Regulatory assets, current	295,000,000			295,000,000
Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2013 FPSC Settlement Agreement [Member]
Public Utilities, General Disclosures [Line Items]
Acceleration of cash recovery through fuel clause	130,000,000
Cost Cap for customers	1,466,000,000			1,466,000,000
Approved return on equity percentage amount by state commission	7.35%
Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2013 FPSC Settlement Agreement [Member] | Amount Subject To Cost Cap [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets, noncurrent	1,377,000,000			1,377,000,000
Duke Energy Florida [Member] | Crystal River Unit 3 [Member] | 2013 FPSC Settlement Agreement [Member] | Uprate And ISFSI Projects [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets, noncurrent	260,000,000			260,000,000
Duke Energy Florida [Member] | Levy Nuclear Station [Member]
Public Utilities, General Disclosures [Line Items]
Restructuring Reserve	25,000,000			25,000,000
Duke Energy Florida [Member] | Levy Nuclear Station [Member] | 2013 FPSC Settlement Agreement [Member]
Public Utilities, General Disclosures [Line Items]
Net unrecovered investment	180,000,000			180,000,000
Net property, plant and equipment	91,000,000			91,000,000
Regulatory assets, current	89,000,000			89,000,000
Impairment charges	65,000,000
Duke Energy Florida [Member] | Citrus County Station [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC	1,500,000,000			1,500,000,000
Duke Energy Florida [Member] | Suwannee Station [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC	197,000,000			197,000,000
Duke Energy Florida [Member] | Hines Energy Complex [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC	160,000,000			160,000,000
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Restructuring Reserve	6,000,000	2,000,000		6,000,000
Net property, plant and equipment	4,937,000,000	8,235,000,000		4,937,000,000
Regulatory assets, current	49,000,000	57,000,000		49,000,000
Limit of Total Capital	30.00%			30.00%
Capitalized interest	10,000,000	11,000,000	13,000,000
Impairment charges	94,000,000	5,000,000	2,000,000
Approved MVP Proposals	17
MISO estimate of Duke Energy Ohio's MVP obligation	2,700,000,000
Regulatory assets, noncurrent	512,000,000	471,000,000		512,000,000
Regulatory liability, noncurrent	241,000,000	262,000,000		241,000,000
Regulatory assets	561,000,000	528,000,000		561,000,000
Capital expenditures	322,000,000	434,000,000	514,000,000
Duke Energy Ohio [Member] | Capacity Rider Filing [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Requested rate increase amount to state commission	729,000,000
Duke Energy Ohio [Member] | Electric Rate Case [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	49,000,000
Approved percentage rate increase by state commission	2.90%
Approved return on equity percentage amount by state commission	9.84%
Rate increase begin date	1-May-13
Duke Energy Ohio [Member] | Natural Gas Rate Case [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	9.84%
Duke Energy Ohio [Member] | Mgp Remediation [Member]
Public Utilities, General Disclosures [Line Items]
Required Bond Amount	2,500,000			2,500,000
Duke Energy Ohio [Member] | Mgp Remediation [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Approved rate increase amount by state commission	56,000,000
Regulatory assets	115,000,000			115,000,000
Duke Energy Ohio [Member] | FERC Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	12.38%
Percentage Recovered Through Future Rate Case	30.00%
Duke Energy Ohio [Member] | FERC Complaint 1 [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	11.38%
Duke Energy Ohio [Member] | W.C. Beckjord Station [Member]
Public Utilities, General Disclosures [Line Items]
Gallons of Fuel Released	9,000			9,000
Duke Energy Ohio [Member] | RTO Realignment [Member]
Public Utilities, General Disclosures [Line Items]
Restructuring Reserve	94,000,000	95,000,000		94,000,000
Regulatory assets	74,000,000			74,000,000
Duke Energy Ohio [Member] | Dayton Power and Light [Member] | East Bend Station [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	31.00%			31.00%
Capital expenditures	12,400,000
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	8,815,000,000	8,576,000,000		8,815,000,000
Regulatory assets, current	93,000,000	118,000,000		93,000,000
Capitalized interest	6,000,000	9,000,000	39,000,000
Impairment charges	0	0	579,000,000
Regulatory assets, noncurrent	685,000,000	717,000,000		685,000,000
Regulatory liability, noncurrent	796,000,000	782,000,000		796,000,000
Regulatory assets	778,000,000	835,000,000		778,000,000
Capital expenditures	625,000,000	545,000,000	718,000,000
Duke Energy Indiana [Member] | Retired Generation Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory assets	56,000,000	61,000,000		56,000,000
Duke Energy Indiana [Member] | FERC Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	12.38%
Percentage Recovered Through Future Rate Case	0.50%
Duke Energy Indiana [Member] | FERC Complaint 1 [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	9.15%
Duke Energy Indiana [Member] | FERC Complaint 2 [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage amount by state commission	8.67%
Duke Energy Indiana [Member] | Grid Infrastructure Improvement Plan [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost	1,900,000,000			1,900,000,000
Percentage Recovered Through Rider	80.00%
Percentage Recovered Through Future Rate Case	20.00%
Duke Energy Indiana [Member] | Edwardsport IGCC Plant [Member]
Public Utilities, General Disclosures [Line Items]
Percent of AFUDC Allowed	85.00%
Impairment charges			631,000,000	897,000,000
Duke Energy Indiana [Member] | Edwardsport IGCC Plant [Member] | Edwardsport Event November 20, 2007 [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC	1,985,000,000			1,985,000,000
Duke Energy Indiana [Member] | Edwardsport IGCC Plant [Member] | Edwardsport Event December 27, 2012 [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC	2,595,000,000			2,595,000,000
Duke Energy Indiana [Member] | Edwardsport IGCC Plant [Member] | Edwardsport Event September 8, 2014 [Member]
Public Utilities, General Disclosures [Line Items]
Capitalized interest	61,000,000
Dominion Resources [Member] | Atlantic Coast Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage	45.00%			45.00%
Scenario, Forecast [Member] | Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Payments to Acquire Businesses, Gross					$166,000,000

Regulatory_Matters_Schedule_of

Regulatory Matters (Schedule of Regulatory Assets and Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Regulatory Assets Liabilities [Line Items]
Regulatory assets	$12,157	$10,086
Regulatory assets - current	1,115	895
Regulatory assets, noncurrent	11,042	9,191
Regulatory liabilities	6,397	6,265
Regulatory liabilities - current	204	316
Regulatory liabilities - noncurrent	6,193	5,949
Removal Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	5,221	5,308
Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	166	151
Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	150	145
Accrued Pension And Other Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	379	138
Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	37	177
Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	444	346
Asset Retirement Obligations Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	3,017	1,608
Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,015	1,723
Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,659	1,748
Debt Fair Value Adjustment [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,305	1,338
Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,144	1,115
Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	628	450
Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	330	306
Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	76	65
Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	213	210
Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	246	94
Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	296	262
Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	494	459
Gasification Services Agreement Buyout Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	55	75
Transmission Expansion Obligation [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	70	70
Manufactured Gas Plant Environmental Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	115	90
Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	494	473
Duke Energy Carolinas [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,864	1,822
Regulatory assets - current	399	295
Regulatory assets, noncurrent	2,465	1,527
Regulatory liabilities	2,744	2,641
Regulatory liabilities - current	34	65
Regulatory liabilities - noncurrent	2,710	2,576
Duke Energy Carolinas [Member] | Removal Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	2,420	2,423
Duke Energy Carolinas [Member] | Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	25	20
Duke Energy Carolinas [Member] | Accrued Pension And Other Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	76
Duke Energy Carolinas [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	6	45
Duke Energy Carolinas [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	217	153
Duke Energy Carolinas [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	907	123
Duke Energy Carolinas [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	412	347
Duke Energy Carolinas [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	58	68
Duke Energy Carolinas [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	614	555
Duke Energy Carolinas [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	103	98
Duke Energy Carolinas [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	106	140
Duke Energy Carolinas [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	86	82
Duke Energy Carolinas [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	50
Duke Energy Carolinas [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	141	40
Duke Energy Carolinas [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	124	150
Duke Energy Carolinas [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	263	219
Progress Energy [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	5,899	4,508
Regulatory assets - current	491	353
Regulatory assets, noncurrent	5,408	4,155
Regulatory liabilities	2,485	2,499
Regulatory liabilities - current	106	207
Regulatory liabilities - noncurrent	2,379	2,292
Progress Energy [Member] | Removal Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	1,975	2,008
Progress Energy [Member] | Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	70	120
Progress Energy [Member] | Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	125	125
Progress Energy [Member] | Accrued Pension And Other Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	121
Progress Energy [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	23	132
Progress Energy [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	171	114
Progress Energy [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,882	786
Progress Energy [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	812	750
Progress Energy [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,545	1,619
Progress Energy [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	354	331
Progress Energy [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	490	318
Progress Energy [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	203	152
Progress Energy [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	46	55
Progress Energy [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	182	37
Progress Energy [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	155	222
Progress Energy [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	121	137
Progress Energy [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	109	101
Duke Energy Progress [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,962	1,511
Regulatory assets - current	287	127
Regulatory assets, noncurrent	2,675	1,384
Regulatory liabilities	1,903	1,736
Regulatory liabilities - current	71	63
Regulatory liabilities - noncurrent	1,832	1,673
Duke Energy Progress [Member] | Removal Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	1,692	1,637
Duke Energy Progress [Member] | Accrued Pension And Other Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	61
Duke Energy Progress [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	23
Duke Energy Progress [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	127	99
Duke Energy Progress [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,584	389
Duke Energy Progress [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	354	269
Duke Energy Progress [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	152	241
Duke Energy Progress [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	141	113
Duke Energy Progress [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	217	165
Duke Energy Progress [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	193	140
Duke Energy Progress [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	46	50
Duke Energy Progress [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	138	6
Duke Energy Progress [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	43	77
Duke Energy Progress [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	28	19
Duke Energy Progress [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	66	42
Duke Energy Florida [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	2,936	2,950
Regulatory assets - current	203	221
Regulatory assets, noncurrent	2,733	2,729
Regulatory liabilities	582	762
Regulatory liabilities - current	35	144
Regulatory liabilities - noncurrent	547	618
Duke Energy Florida [Member] | Removal Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	283	371
Duke Energy Florida [Member] | Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	70	120
Duke Energy Florida [Member] | Storm Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	125	125
Duke Energy Florida [Member] | Accrued Pension And Other Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	60
Duke Energy Florida [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities		132
Duke Energy Florida [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	44	14
Duke Energy Florida [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	298	397
Duke Energy Florida [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	458	438
Duke Energy Florida [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	1,393	1,378
Duke Energy Florida [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	213	218
Duke Energy Florida [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	273	153
Duke Energy Florida [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	10	12
Duke Energy Florida [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	44	31
Duke Energy Florida [Member] | Nuclear Deferral [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	112	145
Duke Energy Florida [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	93	118
Duke Energy Florida [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	42	60
Duke Energy Ohio [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	561	528
Regulatory assets - current	49	57
Regulatory assets, noncurrent	512	471
Regulatory liabilities	251	289
Regulatory liabilities - current	10	27
Regulatory liabilities - noncurrent	241	262
Duke Energy Ohio [Member] | Removal Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	222	241
Duke Energy Ohio [Member] | Accrued Pension And Other Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	19	21
Duke Energy Ohio [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	10	27
Duke Energy Ohio [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	132	120
Duke Energy Ohio [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	64	72
Duke Energy Ohio [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	7	5
Duke Energy Ohio [Member] | Demand Side Management And Energy Efficiency [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	21	14
Duke Energy Ohio [Member] | Grid Modernization [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	76	65
Duke Energy Ohio [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	6	7
Duke Energy Ohio [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	9	14
Duke Energy Ohio [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	21	21
Duke Energy Ohio [Member] | Transmission Expansion Obligation [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	74	74
Duke Energy Ohio [Member] | Manufactured Gas Plant Environmental Reserve [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	115	90
Duke Energy Ohio [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	36	46
Duke Energy Indiana [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	778	835
Regulatory assets - current	93	118
Regulatory assets, noncurrent	685	717
Regulatory liabilities	850	798
Regulatory liabilities - current	54	16
Regulatory liabilities - noncurrent	796	782
Duke Energy Indiana [Member] | Removal Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	613	645
Duke Energy Indiana [Member] | Amounts To Be Refunded to Customers [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	96	31
Duke Energy Indiana [Member] | Accrued Pension And Other Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	91	77
Duke Energy Indiana [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	8
Duke Energy Indiana [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory liabilities	42	45
Duke Energy Indiana [Member] | Accrued Pension And Post Retirement [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	217	219
Duke Energy Indiana [Member] | Retired Generation Facilities [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	56	61
Duke Energy Indiana [Member] | Net Regulatory Asset Related To Income Taxes [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	111	157
Duke Energy Indiana [Member] | Hedge Cost and Other Deferrals [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	28	29
Duke Energy Indiana [Member] | Vacation Accrual [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	12	13
Duke Energy Indiana [Member] | Deferred Fuel [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	5	43
Duke Energy Indiana [Member] | Post-In-Service Carrying Costs And Deferred Operating Expense [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	228	151
Duke Energy Indiana [Member] | Gasification Services Agreement Buyout Costs [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	55	75
Duke Energy Indiana [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets Liabilities [Line Items]
Regulatory assets	$66	$87

Regulatory_Matters_Schedule_of1

Regulatory Matters (Schedule of MISO Exit fees)(Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$64
Provision/adjustments	5
Cash reductions	-41
Balance, end of period	28
Total regulatory assets	12,157	10,086
Duke Energy Ohio [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	2
Provision/adjustments	5
Cash reductions	-1
Balance, end of period	6
Total regulatory assets	561	528
Duke Energy Ohio [Member] | RTO Realignment [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	95
Provision/adjustments	3
Cash reductions	-4
Balance, end of period	94
Total regulatory assets	$74

Regulatory_Matters_Schedule_of2

Regulatory Matters (Schedule of Net Carrying Value Of Facilities As Well As the Remaining Non-current Regulatory Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	MW
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	$70,046	$69,490
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	1,704
Net property, plant and equipment	239
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	24,672	23,012
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	25,144	23,382
Progress Energy [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	873
Net property, plant and equipment	114
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	15,186	13,650
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	9,955	9,611
Duke Energy Florida [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	873
Net property, plant and equipment	114
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	4,937	8,235
Duke Energy Ohio [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	163
Net property, plant and equipment	9
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Net property, plant and equipment	8,815	8,576
Duke Energy Indiana [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Megawatt of potential plants to be retired, in megawatts	668
Net property, plant and equipment	$116

Commitments_and_Contingencies_1

Commitments and Contingencies (Narrative) (Details) (USD $)	12 Months Ended	0 Months Ended		24 Months Ended	0 Months Ended	1 Months Ended
	Dec. 31, 2014	Aug. 10, 2011	Aug. 09, 2011	Dec. 31, 2000	Oct. 03, 2012	Dec. 31, 2009	Feb. 08, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2015
	reactor						gal
							T
Insurance [Abstract]
Insured public liability limit per nuclear incident	$13,600,000,000
Primary nuclear liability program coverage	375,000,000
Excess nuclear liability program coverage	13,200,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance	127,000,000
Number of licensed nuclear reactors	104
Annual payment limit to pro rata assessments	19,000,000
Industry aggregate limit	3,200,000,000
Sublimit for non-nuclear terrorist events	1,830,000,000
Sublimit property damage losses	1,500,000,000
Additional nuclear accident limit	1,250,000,000
Insurance Coverage Percentage Initial Weeks	100.00%
Accidental Outage Insurance Coverage Initial Weeks	365 days
Insurance Coverage Percentage Additional Weeks	80.00%
Accidental Outage Insurance Coverage Additional Weeks	770 days
Sublimit accidental outage recovery	328,000,000
Maximum Magnitude of Retroactive Premiums	10
Maximum Period for Retroactive Premium Assessment	6 years
Weeks of Sublimits for Accidental Outage Coverage	728 days
Excess Property Insurance Max Retroactive Assessments	17,000,000
Potential Obligation percentage	100.00%
North Carolina Ash Basins [Member]
Valuation and Qualifying Accounts [Abstract]
Facilities with Ash Basins	14
Ash Basins Fines and Restitution [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense	68,000,000
Ash Basins Community Service and Mitigation [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense	34,000,000
Brazil Expansion Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Obligation to expand installed generation capacity, percent		15.00%	15.00%
Environmental Reserves [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	89,000,000
Duke Energy Carolinas [Member]
Insurance [Abstract]
Maximum potentional retroactive premium assessments for primary property insurance	73,000,000
Maximum potentional retroactive premium assessments for accidental outage insurance	32,000,000
Duke Energy Carolinas [Member] | McGuire Nuclear Station [Member]
Insurance [Abstract]
Accidental outage insurance coverage policy limit	490,000,000
Duke Energy Carolinas [Member] | Oconee Nuclear Station [Member]
Insurance [Abstract]
Additional Non Nuclear Accident Limit	750,000,000
Accidental outage insurance coverage policy limit	381,000,000
Duke Energy Carolinas [Member] | Catawba Nuclear Station [Member]
Insurance [Abstract]
Additional nuclear accident limit	1,250,000,000
Additional Non Nuclear Accident Limit	750,000,000
Accidental outage insurance coverage policy limit	490,000,000
Excess Property Insurance Max Retroactive Assessments	7,000,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Dan River [Member]
Valuation and Qualifying Accounts [Abstract]
Environmental Remediation Expense	24,000,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Dan River [Member] | Minimum [Member]
Valuation and Qualifying Accounts [Abstract]
Estimated amount of ash released, in tons							30,000
Estimated amount of ash basin water released, in gallons							24,000,000
Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | Dan River [Member] | Maximum [Member]
Valuation and Qualifying Accounts [Abstract]
Estimated amount of ash released, in tons							39,000
Estimated amount of ash basin water released, in gallons							27,000,000
Duke Energy Carolinas [Member] | New Source Review Provisions Of Clean Air Act [Member]
Valuation and Qualifying Accounts [Abstract]
Maximum civil penalties per day for each violation				37,500
Projects with Alleged NSR Violations	29
Number of Coal Plants with Alleged NSR Violations	25
Loss contingency, pending claims, number	13
Remaining Number of Coal Plants with Alleged NSR Violations	13
Number of Coal Plants	11
Duke Energy Carolinas [Member] | Asbestos Issue [Member]
Valuation and Qualifying Accounts [Abstract]
Asbestos-related injuries and damages reserves	575,000,000							616,000,000
Reinsurance retention policy, amount retained	476,000,000
Reinsurance retention policy, excess retention, amount reinsured	864,000,000
Probable insurance recoveries	616,000,000							649,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number	28
Asbestos-related injuries and damages reserves	7,000,000
Duke Energy Carolinas [Member] | Asbestos Issue [Member] | Non Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number	54
Asbestos-related injuries and damages reserves	11,000,000
Duke Energy Carolinas [Member] | Environmental Reserves [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	25,000,000
Progress Energy [Member] | Synthetic Fuels [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, damages paid, value						154,000,000
Damages awarded to plaintiff					90,000,000
Gain recognized in period									63,000,000
Progress Energy [Member] | Environmental Reserves [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	15,000,000
Duke Energy Progress [Member]
Commitments And Contingencies [Line Items]
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
Insurance [Abstract]
Maximum potentional retroactive premium assessments for primary property insurance	60,000,000
Maximum potentional retroactive premium assessments for accidental outage insurance	16,000,000
Duke Energy Progress [Member] | Robinson Nuclear Station [Member]
Insurance [Abstract]
Accidental outage insurance coverage policy limit	329,000,000
Duke Energy Progress [Member] | Brunswick Nuclear Station [Member]
Insurance [Abstract]
Accidental outage insurance coverage policy limit	419,000,000
Duke Energy Progress [Member] | Shearon Harris Nuclear Station [Member]
Insurance [Abstract]
Accidental outage insurance coverage policy limit	384,000,000
Duke Energy Progress [Member] | Spent Nuclear Fuels [Member]
Valuation and Qualifying Accounts [Abstract]
Gain related to litigation settlement	83,000,000
Duke Energy Progress [Member] | Environmental Reserves [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	1,000,000
Duke Energy Florida [Member]
Commitments And Contingencies [Line Items]
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
Insurance [Abstract]
Maximum potentional retroactive premium assessments for primary property insurance	8,000,000
Duke Energy Florida [Member] | Crystal River Unit 3 [Member]
Insurance [Abstract]
Sublimit property damage losses	1,100,000,000
Duke Energy Florida [Member] | Spent Nuclear Fuels [Member]
Valuation and Qualifying Accounts [Abstract]
Gain related to litigation settlement	21,000,000
Duke Energy Florida [Member] | Environmental Reserves [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	14,000,000
Duke Energy Florida [Member] | Westinghouse Electric Company Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, damages sought, value	510,000,000
Gain contingency, unrecorded amount	54,000,000
Duke Energy Ohio [Member] | Environmental Reserves [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	42,000,000
Duke Energy Indiana [Member] | Environmental Reserves [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, range of possible loss, portion not acccrued	7,000,000
Operating Expense [Member] | Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense	72,000,000
Operating Expense [Member] | Duke Energy Progress [Member] | North Carolina Ash Basins [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Litigation Settlement, Expense	30,000,000
Subsequent Event [Member] | Duke Energy Carolinas [Member] | North Carolina Ash Basins [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Minimum Master Credit Facility Balance Required										250,000,000
Subsequent Event [Member] | Duke Energy Progress [Member] | North Carolina Ash Basins [Member] | USDOJ [Member]
Valuation and Qualifying Accounts [Abstract]
Minimum Master Credit Facility Balance Required										$250,000,000

Commitments_and_Contingencies_2

Commitments and Contingencies (Schedule of Reserves) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Environmental Matters Details [Line Items]
Reserves for legal matters	$323	$204
Duke Energy Carolinas [Member]
Environmental Matters Details [Line Items]
Reserves for legal matters	72
Progress Energy [Member]
Environmental Matters Details [Line Items]
Reserves for legal matters	93	78
Duke Energy Progress [Member]
Environmental Matters Details [Line Items]
Reserves for legal matters	37	10
Duke Energy Florida [Member]
Environmental Matters Details [Line Items]
Reserves for legal matters	$36	$43

Commitments_and_Contingencies_3

Commitments and Contingencies (Schedule of Environmental Loss Contingencies)(Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	$79	$75	$61
Provision/adjustments	32	26	39
Cash reductions	-14	-22	-25
Ending balance	97	79	75
Duke Energy Carolinas [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	11	12	12
Provision/adjustments	-1		1
Cash reductions		-1	-1
Ending balance	10	11	12
Progress Energy [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	27	33	23
Provision/adjustments	1	4	19
Cash reductions	-11	-10	-9
Ending balance	17	27	33
Duke Energy Progress [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	8	14	11
Provision/adjustments	4	-1	5
Cash reductions	-7	-5	-2
Ending balance	5	8	14
Duke Energy Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	19	19	12
Provision/adjustments	-3	5	14
Cash reductions	-4	-5	-7
Ending balance	12	19	19
Duke Energy Ohio [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	27	15	28
Provision/adjustments	28	20	5
Cash reductions	-1	-8	-18
Ending balance	54	27	15
Duke Energy Indiana [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	7	8	9
Provision/adjustments	4	1	3
Cash reductions	-1	-2	-4
Ending balance	$10	$7	$8

Commitments_and_Contingencies_4

Commitments and Contingencies (PurchPower)(Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Duke Energy Progress [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
Duke Energy Progress [Member] | Public Utilities Purchased Power [Member]
Unconditional Purchase Obligations [Abstract]
2015	59
2016	60
2017	61
2018	62
2019	63
Thereafter	93
Total	398
Duke Energy Progress [Member] | Minimum [Member] | Public Utilities Purchased Power [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2019
Duke Energy Progress [Member] | Maximum [Member] | Public Utilities Purchased Power [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2022
Duke Energy Florida [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
Duke Energy Florida [Member] | Public Utilities Purchased Power [Member]
Unconditional Purchase Obligations [Abstract]
2015	244
2016	273
2017	291
2018	306
2019	322
Thereafter	1,907
Total	3,343
Duke Energy Florida [Member] | Minimum [Member] | Public Utilities Purchased Power [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2023
Duke Energy Florida [Member] | Maximum [Member] | Public Utilities Purchased Power [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2043

Commitments_and_Contingencies_5

Commitments and Contingencies (Future Minimum Payments for Operating and Capital Leases) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets
Rental expense on operating leases	$355	$321	$232
Operating Leases, Future Minimum Payments Due [Abstract]
2015	205
2016	198
2017	172
2018	157
2019	148
Thereafter	938
Total future minimum lease payments	1,818
Capital Leases, Future Minimum Payments Due [Abstract]
2015	178
2016	188
2017	190
2018	198
2019	208
Thereafter	1,771
Minimum annual payments	2,733
Less amount representing interest	-1,305
Total	1,428
Duke Energy Carolinas [Member]
Operating Leased Assets
Rental expense on operating leases	41	39	38
Operating Leases, Future Minimum Payments Due [Abstract]
2015	33
2016	29
2017	26
2018	20
2019	17
Thereafter	64
Total future minimum lease payments	189
Capital Leases, Future Minimum Payments Due [Abstract]
2015	6
2016	6
2017	7
2018	7
2019	8
Thereafter	60
Minimum annual payments	94
Less amount representing interest	-67
Total	27
Progress Energy [Member]
Operating Leased Assets
Rental expense on operating leases	257	225	232
Operating Leases, Future Minimum Payments Due [Abstract]
2015	129
2016	130
2017	111
2018	109
2019	103
Thereafter	709
Total future minimum lease payments	1,291
Capital Leases, Future Minimum Payments Due [Abstract]
2015	46
2016	47
2017	47
2018	48
2019	51
Thereafter	678
Minimum annual payments	917
Less amount representing interest	-603
Total	314
Duke Energy Progress [Member]
Operating Leased Assets
Rental expense on operating leases	161	153	164
Operating Leases, Future Minimum Payments Due [Abstract]
2015	65
2016	66
2017	65
2018	64
2019	58
Thereafter	421
Total future minimum lease payments	739
Capital Leases, Future Minimum Payments Due [Abstract]
2015	21
2016	21
2017	21
2018	22
2019	25
Thereafter	398
Minimum annual payments	508
Less amount representing interest	-361
Total	147
Duke Energy Florida [Member]
Operating Leased Assets
Rental expense on operating leases	96	72	68
Operating Leases, Future Minimum Payments Due [Abstract]
2015	64
2016	64
2017	46
2018	45
2019	45
Thereafter	288
Total future minimum lease payments	552
Capital Leases, Future Minimum Payments Due [Abstract]
2015	26
2016	26
2017	26
2018	26
2019	26
Thereafter	280
Minimum annual payments	410
Less amount representing interest	-242
Total	168
Duke Energy Ohio [Member]
Operating Leased Assets
Rental expense on operating leases	17	14	14
Operating Leases, Future Minimum Payments Due [Abstract]
2015	12
2016	11
2017	9
2018	7
2019	6
Thereafter	18
Total future minimum lease payments	63
Capital Leases, Future Minimum Payments Due [Abstract]
2015	7
2016	7
2017	3
2018	4
2019	2
Minimum annual payments	23
Less amount representing interest	-3
Total	20
Duke Energy Indiana [Member]
Operating Leased Assets
Rental expense on operating leases	21	22	20
Operating Leases, Future Minimum Payments Due [Abstract]
2015	17
2016	15
2017	13
2018	10
2019	9
Thereafter	9
Total future minimum lease payments	73
Capital Leases, Future Minimum Payments Due [Abstract]
2015	4
2016	4
2017	2
2018	2
2019	2
Thereafter	42
Minimum annual payments	56
Less amount representing interest	-39
Total	$17

Debt_and_Credit_Facilities_Nar

Debt and Credit Facilities (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2015	Mar. 31, 2015
Other Debt Matters [Abstract]
Subsidiary debt guaranteed by parent	$767,000,000	$811,000,000
Demand notes, maximum amount available for sale	3,000,000,000
Demand notes, maximum amount outstanding	1,500,000,000
Principal amount of demand notes	968,000,000	836,000,000
Other Loans [Abstract]
Other loans outstanding against cash surrender value of life insurance policies	603,000,000	571,000,000
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Line of Credit Facility [Abstract]
Facility size	6,000,000,000
Line of Credit Facility, Affiliated Borrower	The Duke Energy Registrants, excluding Progress Energy, each have borrowing capacity under the Master Credit Facility up to specified sublimits for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower.
Subsequent Event [Member]
Line of Credit Facility [Abstract]
Facility size			7,500,000,000
Duke Energy Carolinas [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Progress Energy [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Progress [Member]
Other Loans [Abstract]
Other loans outstanding against cash surrender value of life insurance policies	44,000,000	48,000,000
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Florida [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Ohio [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
Duke Energy Indiana [Member]
Restrictive Debt Covenants [Abstract]
Debt to total capitalization percentage, for each borrower	0.65
USDOJ [Member] | Duke Energy Carolinas [Member] | Subsequent Event [Member] | North Carolina Ash Basins [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required				250,000,000
USDOJ [Member] | Duke Energy Progress [Member] | Subsequent Event [Member] | North Carolina Ash Basins [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required				250,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Commercial Paper	-2,021,000,000
Line of Credit Facility [Abstract]
Facility size	6,000,000,000
Revolving Credit Facility [Member] | Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Long-term Commercial Paper	-300,000,000
Line of Credit Facility [Abstract]
Facility size	1,000,000,000
Revolving Credit Facility [Member] | Duke Energy Progress [Member]
Line of Credit Facility [Abstract]
Facility size	750,000,000
Revolving Credit Facility [Member] | Duke Energy Florida [Member]
Debt Instrument [Line Items]
Long-term Commercial Paper	-29,000,000
Line of Credit Facility [Abstract]
Facility size	650,000,000
Revolving Credit Facility [Member] | Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Long-term Commercial Paper	-38,000,000
Line of Credit Facility [Abstract]
Facility size	650,000,000
Revolving Credit Facility [Member] | Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Long-term Commercial Paper	-175,000,000
Line of Credit Facility [Abstract]
Facility size	700,000,000
Proceeds Loaned To Subsidiary Registrants [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Commercial Paper	($475,000,000)

Debt_and_Credit_Facilities_Sum

Debt and Credit Facilities (Summary of Debt and Related Terms) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Unsecured Debt	12,937	13,550
Secured Debt	2,806	2,559
First mortgage bonds	19,180	17,831
Capital leases	1,428	1,516
Other debt		8
Tax exempt bonds	1,296	2,356
Notes Payable And Commercial Paper	2,989	1,289
Fair value hedge carrying value adjustment	8	9
Unamortized debt discount and premium, net	1,890	1,977
Total debt	42,534	41,095
Short-term notes payable and commercial paper	-2,514	-839
Current maturities of long-term debt	-2,807	-2,104
Total long-term debt	37,213	38,152
Short term obligations classified as long-term debt	1,022	1,121
Unsecured Debt [Member]
Debt Instrument [Line Items]
Weighted-average rate	4.92%	5.18%
Debt maturity date, start	31-Dec-15	31-Dec-14
Debt maturity date, end	31-Dec-73	31-Dec-39
Secured Debt [Member]
Debt Instrument [Line Items]
Weighted-average rate	2.50%	2.69%
Debt maturity date, start	31-Dec-16	31-Dec-14
Debt maturity date, end	31-Dec-37	31-Dec-37
First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Weighted-average rate	4.76%	4.90%
Debt maturity date, start	31-Dec-15	31-Dec-15
Debt maturity date, end	31-Dec-44	31-Dec-43
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Weighted-average rate	5.30%	5.23%
Debt maturity date, start	31-Dec-15	31-Dec-14
Debt maturity date, end	31-Dec-51	31-Dec-51
Other Debt [Member]
Debt Instrument [Line Items]
Weighted-average rate		4.77%
Debt maturity date, end		31-Dec-27
Tax Exempt Bonds [Member]
Debt Instrument [Line Items]
Weighted-average rate	2.13%	1.28%
Debt maturity date, start	31-Dec-15	31-Dec-14
Debt maturity date, end	31-Dec-41	31-Dec-41
Short term obligations classified as long-term debt	347	471
Notes Payable And Commercial Paper [Member]
Debt Instrument [Line Items]
Weighted-average rate	0.70%	1.02%
Weighted-average days to maturity	27 days	49 days
Short term obligations classified as long-term debt	475	450
Revolving Loan [Member]
Debt Instrument [Line Items]
Short term obligations classified as long-term debt	200	200
Purchase Accounting Adjustments [Member]
Debt Instrument [Line Items]
Unamortized debt discount and premium, net	1,975	2,067
Total Debt [Member]
Debt Instrument [Line Items]
Weighted-average rate	4.29%	4.52%
Long-term Debt [Member]
Debt Instrument [Line Items]
Weighted-average rate	4.58%	4.59%
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Unsecured Debt	1,155	1,157
Secured Debt	400	400
First mortgage bonds	6,161	6,161
Capital leases	27	30
Tax exempt bonds	355	395
Money pool borrowings	300	300
Fair value hedge carrying value adjustment	8	9
Unamortized debt discount and premium, net	-15	-16
Total debt	8,391	8,436
Current maturities of long-term debt	-507	-47
Total long-term debt	7,884	8,389
Short term obligations classified as long-term debt	335	375
Duke Energy Carolinas [Member] | Tax Exempt Bonds [Member]
Debt Instrument [Line Items]
Short term obligations classified as long-term debt	35	75
Duke Energy Carolinas [Member] | Notes Payable And Commercial Paper [Member]
Debt Instrument [Line Items]
Short term obligations classified as long-term debt	300	300
Progress Energy [Member]
Debt Instrument [Line Items]
Unsecured Debt	3,850	4,150
Secured Debt	525	305
First mortgage bonds	9,800	8,450
Capital leases	314	327
Tax exempt bonds	291	910
Money pool borrowings	835	1,213
Unamortized debt discount and premium, net	-26	-27
Total debt	15,589	15,328
Short-term money pool borrowings	-835	-1,213
Current maturities of long-term debt	-1,507	-485
Total long-term debt	13,247	13,630
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Secured Debt	300	305
First mortgage bonds	5,475	4,125
Capital leases	146	148
Tax exempt bonds	291	669
Money pool borrowings		462
Unamortized debt discount and premium, net	-11	-12
Total debt	6,201	5,697
Short-term money pool borrowings		-462
Current maturities of long-term debt	-945	-174
Total long-term debt	5,256	5,061
Duke Energy Progress [Member] | Purchase Accounting Adjustments [Member]
Debt Instrument [Line Items]
Capital leases	129	144
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Unsecured Debt	150	150
Secured Debt	225
First mortgage bonds	4,325	4,325
Capital leases	168	179
Tax exempt bonds		241
Money pool borrowings	84	181
Unamortized debt discount and premium, net	-8	-9
Total debt	4,944	5,067
Short-term money pool borrowings	-84	-181
Current maturities of long-term debt	-562	-11
Total long-term debt	4,298	4,875
Duke Energy Florida [Member] | Purchase Accounting Adjustments [Member]
Debt Instrument [Line Items]
Capital leases	787	838
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Unsecured Debt	773	805
First mortgage bonds	900	900
Capital leases	20	27
Other debt		8
Tax exempt bonds	77	479
Money pool borrowings	516	43
Unamortized debt discount and premium, net	-29	-31
Total debt	2,257	2,231
Short-term money pool borrowings	-491	-43
Current maturities of long-term debt	-157	-47
Total long-term debt	1,609	2,141
Short term obligations classified as long-term debt	52	111
Duke Energy Ohio [Member] | Tax Exempt Bonds [Member]
Debt Instrument [Line Items]
Short term obligations classified as long-term debt	27	111
Duke Energy Ohio [Member] | Notes Payable And Commercial Paper [Member]
Debt Instrument [Line Items]
Short term obligations classified as long-term debt	25
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Unsecured Debt	742	744
First mortgage bonds	2,319	2,319
Capital leases	16	20
Tax exempt bonds	573	573
Money pool borrowings	221	150
Unamortized debt discount and premium, net	-9	-10
Total debt	3,862	3,796
Short-term money pool borrowings	-71
Current maturities of long-term debt	-5	-5
Total long-term debt	3,786	3,791
Short term obligations classified as long-term debt	435	435
Duke Energy Indiana [Member] | Tax Exempt Bonds [Member]
Debt Instrument [Line Items]
Short term obligations classified as long-term debt	285	285
Duke Energy Indiana [Member] | Notes Payable And Commercial Paper [Member]
Debt Instrument [Line Items]
Short term obligations classified as long-term debt	150	150

Debt_and_Credit_Facilities_Sum1

Debt and Credit Facilities (Summary of Debt Issuances) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Apr. 30, 2014
Debt Instrument [Line Items]
Debt issuances	$2,922,000,000	$4,023,000,000
April 2014 3.75% Senior Unsecured Notes Maturing April 2024 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Apr-14
Debt maturity date	30-Apr-24
Debt issuances	600,000,000
Interest rate	3.75%
Repayments of Debt	402,000,000
April 2014 0.613% Senior Unsecured Floating Notes Maturing April 2017 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Apr-14
Debt maturity date	30-Apr-17
Debt issuances	400,000,000
Interest rate	0.61%
Fixed credit spread	0.38%
Repayments of Debt	402,000,000
June 2014 11.970% Senior Unsecured Floating Notes Maturing May 2019 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Jun-14
Debt maturity date	31-May-19
Debt issuances	108,000,000
Interest rate	11.97%
Repayments of Debt	196,000,000
June 2014 13.680% Senior Unsecured Floating Notes Maturing May 2021 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Jun-14
Debt maturity date	31-May-21
Debt issuances	110,000,000
Interest rate	13.68%
Repayments of Debt	196,000,000
March 2014 0.863% Secured Credit Facility Maturing March 2017 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Mar-14
Debt maturity date	31-Mar-17
Debt issuances	225,000,000
Interest rate	0.86%
July 2014 5.340% Secured Debt Maturing July 2036 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Jul-14
Debt maturity date	31-Jul-36
Debt issuances	129,000,000
Interest rate	5.34%
March 2014 4.375% First Mortgage Bonds Maturing March 2044 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Mar-14
Debt maturity date	31-Mar-44
Debt issuances	400,000,000
Interest rate	4.38%
March 2014 0.435% First Mortgage Bonds Maturing March 2017[Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Mar-14
Debt maturity date	31-Mar-17
Debt issuances	250,000,000
Interest rate	0.44%
Fixed credit spread	0.20%
November 2014 4.150% Fixed First Mortgage Bonds Maturing December 2044 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Nov-14
Debt maturity date	31-Dec-44
Debt issuances	500,000,000
Interest rate	4.15%
Repayments of Debt	450,000,000
November 2014 0.432% Floating First Mortgage Bonds Maturing November 2017 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Nov-14
Debt maturity date	30-Nov-17
Debt issuances	200,000,000
Interest rate	0.43%
Fixed credit spread	0.20%
Repayments of Debt	450,000,000
January 2013 5.125% Junior Subordinated Debentures Maturing January 2073 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Jan-13
Debt maturity date		31-Jan-73
Debt issuances		500,000,000
Interest rate		5.13%
Debt instrument, call date, earliest		31-Jan-18
June 2013 2.100% Senior Notes Maturing June 2018 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		30-Jun-13
Debt maturity date		30-Jun-18
Debt issuances		500,000,000
Interest rate		2.10%
Repayments of Debt		250,000,000
August 2013 11.000% Non Convertible Debentures Maturing August 2018 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Aug-13
Debt maturity date		30-Aug-23
Debt maturity date, start		31-Aug-18
Debt issuances		220,000,000
Interest rate		11.00%
Repayments of Debt		200,000,000
October 2013 3.950% Senior Notes Maturing October 2023 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Oct-13
Debt maturity date		31-Oct-23
Debt issuances		400,000,000
Interest rate		3.95%
February 2013 2.043% Term Loans Maturing December 2030 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		28-Feb-13
Debt maturity date		31-Dec-30
Debt issuances		203,000,000
Interest rate		2.04%
Percentage of debt hedged by interest rate derivatives		95.00%
February 2013 4.740% Term Loans Maturing June 2037 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		28-Feb-13
Debt maturity date		30-Jun-37
Debt issuances		220,000,000
Interest rate		4.74%
April 2013 5.456% Non Recourse Secured Credit Facility Maturing April 2026 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		30-Apr-13
Debt maturity date		30-Apr-26
Debt issuances		230,000,000
Interest rate		5.46%
Percentage of debt hedged by interest rate derivatives		75.00%
Incremental debt proceeds		40,000,000
April 2013 5.456% Non Recourse Secured Credit Facility Maturing April 2026 [Member] | Bridge Loan [Member]
Debt Instrument [Line Items]
Repayments of Debt		190,000,000
December 2013 0.852% Secured ARS Maturing December 2016 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		20-Dec-13
Debt maturity date		20-Dec-16
Debt issuances		300,000,000
Interest rate		0.85%
March 2013 4.100% First Mortgage Bonds Maturing March 2043 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Mar-13
Debt maturity date		31-Mar-43
Debt issuances		500,000,000
Interest rate		4.10%
July 2013 4.900% First Mortgage Bonds Maturing July 2043 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Jul-13
Debt maturity date		31-Jul-43
Debt issuances		350,000,000
Interest rate		4.90%
Repayments of Debt		400,000,000
July 2013 0.619% First Mortgage Bonds Maturing July 2016 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Jul-13
Debt maturity date		31-Jul-16
Debt issuances		150,000,000
Interest rate		0.62%
Fixed credit spread		0.35%
September 2013 3.800% First Mortgage Bonds Maturing September 2023 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		30-Sep-13
Debt maturity date		30-Sep-23
Debt issuances		300,000,000
Interest rate		3.80%
Repayments of Debt		250,000,000
September 2013 0.400% First Mortgage Bonds Maturing March 2015 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		30-Sep-13
Debt maturity date		31-Mar-15
Debt issuances		150,000,000
Interest rate		0.40%
Fixed credit spread		0.14%
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances	1,000,000,000	1,400,000,000
Parent Company [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances			1,000,000,000
Parent Company [Member] | April 2014 3.75% Senior Unsecured Notes Maturing April 2024 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Apr-14
Debt maturity date	30-Apr-24
Debt issuances	600,000,000
Interest rate	3.75%
Repayments of Debt	402,000,000
Parent Company [Member] | April 2014 0.613% Senior Unsecured Floating Notes Maturing April 2017 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Apr-14
Debt maturity date	30-Apr-17
Debt issuances	400,000,000
Fixed credit spread	0.38%
Repayments of Debt	402,000,000
Parent Company [Member] | January 2013 5.125% Junior Subordinated Debentures Maturing January 2073 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Jan-13
Debt maturity date		31-Jan-73
Debt issuances		500,000,000
Interest rate		5.13%
Parent Company [Member] | June 2013 2.100% Senior Notes Maturing June 2018 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		30-Jun-13
Debt maturity date		30-Jun-18
Debt issuances		500,000,000
Interest rate		2.10%
Repayments of Debt		250,000,000
Parent Company [Member] | October 2013 3.950% Senior Notes Maturing October 2023 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Oct-13
Debt maturity date		31-Oct-23
Debt issuances		400,000,000
Interest rate		3.95%
Progress Energy [Member] | January 2013 5.125% Junior Subordinated Debentures Maturing January 2073 [Member] | Corporate Debt Securities [Member]
Debt Instrument [Line Items]
Interest rate		7.10%
Repayments of Debt		300,000,000
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Debt issuances	1,350,000,000	800,000,000
Duke Energy Progress [Member] | March 2014 4.375% First Mortgage Bonds Maturing March 2044 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Mar-14
Debt maturity date	31-Mar-44
Debt issuances	400,000,000
Duke Energy Progress [Member] | March 2014 0.435% First Mortgage Bonds Maturing March 2017[Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Mar-14
Debt maturity date	31-Mar-17
Debt issuances	250,000,000
Fixed credit spread	0.20%
Duke Energy Progress [Member] | November 2014 4.150% Fixed First Mortgage Bonds Maturing December 2044 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Nov-14
Debt maturity date	31-Dec-44
Debt issuances	500,000,000
Repayments of Debt	450,000,000
Duke Energy Progress [Member] | November 2014 0.432% Floating First Mortgage Bonds Maturing November 2017 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Nov-14
Debt maturity date	30-Nov-17
Debt issuances	200,000,000
Fixed credit spread	0.20%
Repayments of Debt	450,000,000
Duke Energy Progress [Member] | December 2013 0.852% Secured ARS Maturing December 2016 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date		20-Dec-13
Debt maturity date		31-Dec-16
Debt issuances		300,000,000
Interest rate		0.85%
Duke Energy Progress [Member] | March 2013 4.100% First Mortgage Bonds Maturing March 2043 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Mar-13
Debt maturity date		31-Mar-43
Debt issuances		500,000,000
Interest rate		4.10%
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Debt issuances	225,000,000
Duke Energy Florida [Member] | March 2014 0.863% Secured Credit Facility Maturing March 2017 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuance date	1-Mar-14
Debt maturity date	31-Mar-17
Debt issuances	225,000,000
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Debt issuances		450,000,000
Duke Energy Ohio [Member] | September 2013 3.800% First Mortgage Bonds Maturing September 2023 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		30-Sep-13
Debt maturity date		30-Sep-23
Debt issuances		300,000,000
Interest rate		3.80%
Repayments of Debt		250,000,000
Duke Energy Ohio [Member] | September 2013 0.400% First Mortgage Bonds Maturing March 2015 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		30-Sep-13
Debt maturity date		31-Mar-15
Debt issuances		150,000,000
Interest rate		0.40%
Fixed credit spread		0.14%
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Debt issuances		500,000,000
Duke Energy Indiana [Member] | July 2013 4.900% First Mortgage Bonds Maturing July 2043 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Jul-13
Debt maturity date		31-Jul-43
Debt issuances		350,000,000
Interest rate		4.90%
Repayments of Debt		400,000,000
Duke Energy Indiana [Member] | July 2013 0.619% First Mortgage Bonds Maturing July 2016 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuance date		31-Jul-13
Debt maturity date		31-Jul-16
Debt issuances		$150,000,000
Interest rate		0.62%
Fixed credit spread		0.35%

Debt_and_Credit_Facilities_Ann

Debt and Credit Facilities (Annual Maturities) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$2,807	$2,104
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	2,793
2016	2,980
2017	2,452
2018	3,207
2019	2,810
Thereafter	23,803
Total long-term debt, including current maturities	38,045
Other Debt Obligations [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	214
Duke Energy Carolinas [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	507	47
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	507
2016	756
2017	116
2018	1,505
2019	5
Thereafter	5,502
Total long-term debt, including current maturities	8,391
Duke Energy Carolinas [Member] | 5.300% October 2015 Maturity 1 [Member] | First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	30-Oct-15
Interest rate	5.30%
Current maturities of long-term debt	500
Progress Energy [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	1,507	485
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	1,507
2016	614
2017	940
2018	515
2019	1,418
Thereafter	9,760
Total long-term debt, including current maturities	14,754
Duke Energy Progress [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	945	174
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	945
2016	302
2017	453
2018	3
2019	606
Thereafter	3,892
Total long-term debt, including current maturities	6,201
Duke Energy Progress [Member] | 5.150% April 2015 Maturity 2 [Member] | First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	30-Apr-15
Interest rate	5.15%
Current maturities of long-term debt	300
Duke Energy Progress [Member] | 5.250% December 2015 Maturity 2 [Member] | First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	31-Dec-15
Interest rate	5.25%
Current maturities of long-term debt	400
Duke Energy Progress [Member] | 0.108% January 2015 Maturity 1 [Member] | Tax Exempt Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	31-Jan-15
Interest rate	0.11%
Current maturities of long-term debt	243
Duke Energy Florida [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	562	11
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	562
2016	12
2017	487
2018	512
2019	12
Thereafter	3,275
Total long-term debt, including current maturities	4,860
Duke Energy Florida [Member] | 0.650% November 2015 Maturity 1 [Member] | First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	30-Nov-15
Interest rate	0.65%
Current maturities of long-term debt	250
Duke Energy Florida [Member] | 5.100% December 2015 Maturity 1 [Member] | First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	31-Dec-15
Interest rate	5.10%
Current maturities of long-term debt	300
Duke Energy Ohio [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	157	47
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	157
2016	57
2017	3
2018	28
2019	552
Thereafter	969
Total long-term debt, including current maturities	1,766
Duke Energy Ohio [Member] | 0.375 % March 2015 Debt Maturing [Member] | First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	31-Mar-15
Interest rate	0.38%
Current maturities of long-term debt	150
Duke Energy Indiana [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	5	5
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	5
2016	480
2017	3
2018	153
2019	62
Thereafter	3,088
Total long-term debt, including current maturities	3,791
Parent Company [Member] | 3.350% April 2015 Debt Maturing [Member] | Unsecured Debt [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	30-Apr-15
Interest rate	3.35%
Current maturities of long-term debt	$450

Debt_and_Credit_Facilities_Sch

Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Line of Credit Facility [Line Items]
Facility size	$6,000,000,000
Tax exempt bonds	-1,296,000,000	-2,356,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	6,000,000,000
Long-term Commercial Paper	-2,021,000,000
Outstanding letters of credit	-70,000,000
Tax exempt bonds	-116,000,000
Available capacity	3,793,000,000
Proceeds Loaned To Subsidiary Registrants [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Long-term Commercial Paper	-475,000,000
Duke Energy Carolinas [Member]
Line of Credit Facility [Line Items]
Tax exempt bonds	-355,000,000	-395,000,000
Duke Energy Carolinas [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	1,000,000,000
Long-term Commercial Paper	-300,000,000
Outstanding letters of credit	-4,000,000
Tax exempt bonds	-35,000,000
Available capacity	661,000,000
Progress Energy [Member]
Line of Credit Facility [Line Items]
Tax exempt bonds	-291,000,000	-910,000,000
Duke Energy Progress [Member]
Line of Credit Facility [Line Items]
Tax exempt bonds	-291,000,000	-669,000,000
Duke Energy Progress [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	750,000,000
Outstanding letters of credit	-2,000,000
Available capacity	748,000,000
Duke Energy Florida [Member]
Line of Credit Facility [Line Items]
Tax exempt bonds		-241,000,000
Duke Energy Florida [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	650,000,000
Long-term Commercial Paper	-29,000,000
Outstanding letters of credit	-1,000,000
Available capacity	620,000,000
Duke Energy Ohio [Member]
Line of Credit Facility [Line Items]
Tax exempt bonds	-77,000,000	-479,000,000
Duke Energy Ohio [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	650,000,000
Long-term Commercial Paper	-38,000,000
Available capacity	612,000,000
Duke Energy Indiana [Member]
Line of Credit Facility [Line Items]
Tax exempt bonds	-573,000,000	-573,000,000
Duke Energy Indiana [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	700,000,000
Long-term Commercial Paper	-175,000,000
Outstanding letters of credit	-1,000,000
Tax exempt bonds	-81,000,000
Available capacity	443,000,000
Parent Company [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility size	2,250,000,000
Long-term Commercial Paper	-1,479,000,000
Outstanding letters of credit	-62,000,000
Available capacity	$709,000,000

Guarantees_and_Indemnification2

Guarantees and Indemnifications(Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Liabilities Recorded for Third Party Guarantees [Abstract]
Face value of guarantees	$28	$24
Surety Bond [Member]
Guarantor Obligations [Line Items]
Maximum potential amount of future payments associated with guarantees	44
Guarantor obligations, term	At DecemberB 31, 2014, Duke Energy had guaranteed $44 million of outstanding surety bonds, most of which have no set expiration.
Standby Letters Of Credit [Member]
Guarantor Obligations [Line Items]
Maximum potential amount of future payments associated with guarantees	452
Guarantor obligations, term	At DecemberB 31, 2014, Duke Energy had issued a total of $452 million in letters of credit, which expire between 2015 and 2020.
Unused letters of credit	46
Performance Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum potential amount of future payments associated with guarantees	267
Maximum potential of future amounts associated with guarantees with expiration dates	120
Guarantor obligations, term	The maximum potential amount of future payments required under these guarantees as of DecemberB 31, 2014, was $267 million. Of this amount, $15 million relates to guarantees issued on behalf of less than wholly owned consolidated entities, with the remainder related to guarantees issued on behalf of third parties and unconsolidated affiliates of Duke Energy. Of the guarantees noted above, $120 million of the guarantees expire between 2015 and 2033, with the remaining performance guarantees having no contractual expiration.
Performance Guarantee [Member] | Less Than Wholly Owned Entity [Member]
Guarantor Obligations [Line Items]
Maximum potential amount of future payments associated with guarantees	15
Spectra Capital [Member] | Performance Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum potential amount of future payments associated with guarantees	205
Guarantor obligations, term	At DecemberB 31, 2014, the maximum potential amount of future payments associated with these guarantees was $205 million, the majority of which expires by 2028.
Progress Energy [Member]
Liabilities Recorded for Third Party Guarantees [Abstract]
Face value of guarantees	13	9
Progress Energy [Member] | Indemnification Agreement [Member]
Guarantor Obligations [Line Items]
Maximum potential amount of future payments associated with guarantees	107
Maximum potential amount of future payments associated with guarantees with no expiration date	7
Guarantee obligations, unlimited exposure	Certain indemnifications related to discontinued operations have no limitations as to time or maximum potential future payments.
Guarantor obligations, term	At DecemberB 31, 2014, the estimated maximum exposure for these indemnifications was $107 million, the majority of which expires in 2017. Of this amount, $7 million has no contractual expiration.
Duke Energy Florida [Member]
Liabilities Recorded for Third Party Guarantees [Abstract]
Face value of guarantees	$7	$3

Joint_Ownership_of_Generating_2

Joint Ownership of Generating and Transmission Facilities Joint Ownership of Generating and Transmission Facilities (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
International Energy Brazil-Canoas I and II [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	47.20%
Property, plant, and equipment	$235
Accumulated depreciation	78
Duke Energy Carolinas [Member] | Duke Energy Carolinas Catawba Nuclear Station (Units 1 and 2) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	19.25%
Property, plant, and equipment	886
Accumulated depreciation	534
Construction work in progress	29
Duke Energy Progress [Member] | Duke Energy Progress Mayo Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	83.83%
Property, plant, and equipment	1,111
Accumulated depreciation	360
Construction work in progress	10
Duke Energy Progress [Member] | Shearon Harris Nuclear Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	83.83%
Property, plant, and equipment	3,872
Accumulated depreciation	2,242
Construction work in progress	208
Duke Energy Progress [Member] | Brunswick Nuclear Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	81.67%
Property, plant, and equipment	2,673
Accumulated depreciation	1,372
Construction work in progress	290
Duke Energy Progress [Member] | Duke Energy Progress Roxboro Station (Unit 4) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	87.06%
Property, plant, and equipment	954
Accumulated depreciation	514
Construction work in progress	24
Duke Energy Florida [Member] | Duke Energy Florida Crystal River Nuclear Station (Unit 3) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	91.78%
Duke Energy Florida [Member] | Duke Energy Florida Intercession City Station (Unit P11) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	66.67%
Property, plant, and equipment	24
Accumulated depreciation	14
Duke Energy Ohio [Member] | Duke Energy Ohio Miami Fort Station (Units 7 and 8) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	64.00%
Duke Energy Ohio [Member] | Duke Energy Ohio J.M. Stuart Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	39.00%
Duke Energy Ohio [Member] | Duke Energy Ohio Conesville Station (Unit 4) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	40.00%
Duke Energy Ohio [Member] | Duke Energy Ohio W.M. Zimmer Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	46.50%
Duke Energy Ohio [Member] | Duke Energy Ohio Killen Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	33.00%
Duke Energy Ohio [Member] | Duke Energy Ohio Transmission [Member]
Jointly Owned Utility Plant Interests [Line Items]
Property, plant, and equipment	96
Accumulated depreciation	51
Construction work in progress	1
Duke Energy Indiana [Member] | Duke Energy Indiana Gibson Station (Unit 5) [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	50.05%
Property, plant, and equipment	315
Accumulated depreciation	170
Construction work in progress	6
Duke Energy Indiana [Member] | Vermillion Generation Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owner ownership percentage	62.50%
Property, plant, and equipment	154
Accumulated depreciation	105
Duke Energy Indiana [Member] | Duke Energy Indiana Transmission and local facilities [Member]
Jointly Owned Utility Plant Interests [Line Items]
Property, plant, and equipment	3,918
Accumulated depreciation	$1,633

Asset_Retirement_Obligations_A

Asset Retirement Obligations Asset Retirement Obligations (Narrative)(Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Asset Retirement Obligation [Line Items]
Asset Retirement Obligations, Noncurrent	$8,466	$4,950
Net property, plant and equipment	70,046	69,490
Regulatory assets, noncurrent	11,042	9,191
Regulatory liability, noncurrent	6,193	5,949
Ash Basins [Member]
Asset Retirement Obligation [Line Items]
Number of Ash Basins	32
Number of Plants with Ash Basins	14
Duke Energy Carolinas [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligations, Noncurrent	3,428	1,594
Net property, plant and equipment	24,672	23,012
Regulatory assets, noncurrent	2,465	1,527
Regulatory liability, noncurrent	2,710	2,576
Duke Energy Carolinas [Member] | Ash Basins [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligations, Noncurrent	1,735
Net property, plant and equipment	896
Regulatory assets, noncurrent	839
Duke Energy Progress [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligations, Noncurrent	3,905	1,729
Net property, plant and equipment	15,186	13,650
Regulatory assets, noncurrent	2,675	1,384
Regulatory liability, noncurrent	1,832	1,673
Duke Energy Progress [Member] | Ash Basins [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligations, Noncurrent	1,792
Net property, plant and equipment	603
Regulatory assets, noncurrent	1,152
Removal Costs [Member] | Duke Energy Progress [Member] | Ash Basins [Member]
Asset Retirement Obligation [Line Items]
Regulatory liability, noncurrent	$37

Asset_Retirement_Obligations_R

Asset Retirement Obligations (Rollforward)(Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation [Roll Forward]
Balance as of January 1	$4,958	$5,176
Acquisitions	4	4
Accretion expense	246	239
Liabilities settled	-68	-12
Liabilities incurred in the current year	3,500
Revisions in estimates of cash flows	-174	-449
Balance as of December 31	8,466	4,958
Duke Energy Carolinas [Member]
Asset Retirement Obligation [Roll Forward]
Balance as of January 1	1,594	1,959
Accretion expense	113	122
Liabilities incurred in the current year	1,717
Revisions in estimates of cash flows	4	-487
Balance as of December 31	3,428	1,594
Progress Energy [Member]
Asset Retirement Obligation [Roll Forward]
Balance as of January 1	2,570	2,420
Accretion expense	135	113
Liabilities settled	-68	-12
Liabilities incurred in the current year	1,783
Revisions in estimates of cash flows	291	49
Balance as of December 31	4,711	2,570
Duke Energy Progress [Member]
Asset Retirement Obligation [Roll Forward]
Balance as of January 1	1,737	1,656
Accretion expense	97	80
Liabilities incurred in the current year	1,783
Revisions in estimates of cash flows	288	1
Balance as of December 31	3,905	1,737
Asset retirement obligation, current		8	7
Duke Energy Florida [Member]
Asset Retirement Obligation [Roll Forward]
Balance as of January 1	833	764
Accretion expense	38	33
Liabilities settled	-68	-12
Revisions in estimates of cash flows	3	48
Balance as of December 31	806	833
Duke Energy Ohio [Member]
Asset Retirement Obligation [Roll Forward]
Balance as of January 1	28	28
Accretion expense	2	2
Revisions in estimates of cash flows	-3	-2
Balance as of December 31	27	28
Duke Energy Indiana [Member]
Asset Retirement Obligation [Roll Forward]
Balance as of January 1	30	37
Accretion expense	2
Revisions in estimates of cash flows		-7
Balance as of December 31	$32	$30

Asset_Retirement_Obligations_N

Asset Retirement Obligations (NDTF Information)(Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
NDTF Information [Abstract]
Legally restricted NDTF investments, fair value	$5,182	$4,769
Duke Energy Carolinas [Member]
NDTF Information [Abstract]
Legally restricted NDTF investments, fair value	2,678	2,477
Duke Energy Carolinas [Member] | 2013 Cost Study [Member]
NDTF Information [Abstract]
Decommissioning contribution requirement	21
Decommissioning cost study estimate	3,420
Duke Energy Progress [Member] | 2014 Cost Study [Member]
NDTF Information [Abstract]
Decommissioning contribution requirement	14
Decommissioning cost study estimate	3,062
Duke Energy Florida [Member] | 2013 Cost Study [Member]
NDTF Information [Abstract]
Decommissioning cost study estimate	$1,083

Asset_Retirement_Obligations_N1

Asset Retirement Obligations (Nuclear Operating Licenses)(Details)	12 Months Ended
	Dec. 31, 2014
Duke Energy Carolinas [Member] | Catawba Unit 1 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2043
Duke Energy Carolinas [Member] | Catawba Unit 2 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2043
Duke Energy Carolinas [Member] | McGuire Unit 1 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2041
Duke Energy Carolinas [Member] | McGuire Unit 2 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2043
Duke Energy Carolinas [Member] | Oconee Unit 1 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2033
Duke Energy Carolinas [Member] | Oconee Unit 2 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2033
Duke Energy Carolinas [Member] | Oconee Unit 3 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2034
Duke Energy Progress [Member] | Brunswick Unit 1 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2036
Duke Energy Progress [Member] | Brunswick Unit 2 [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2034
Duke Energy Progress [Member] | Shearon Harris Nuclear Station [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2046
Duke Energy Progress [Member] | Robinson Nuclear Station [Member]
Asset Retirement Obligation [Line Items]
Year of expiration	2030

Property_Plant_and_Equipment_S

Property, Plant and Equipment (Schedule Of Property, Plant and Equipment) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Land	$1,459	$1,481
Nuclear fuel	2,865	2,458
Equipment	1,762	1,557
Construction in process	4,519	3,595
Other	3,497	3,438
Total property, plant and equipment	104,861	103,115
Total accumulated depreciation	-34,824	-33,625
Generation Facilities To Be Retired Net	9
Total net property, plant and equipment	70,046	69,490
Capitalized leases	1,548	1,606
Accumulated amortization on capitalized leases	52	40
Capitalized Interest Costs [Abstract]
Capitalized interest	75	89	176
Minimum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Equipment, estimated useful life, years	3 years	1 year
Other, estimated useful life, in years	5 years	5 years
Maximum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Equipment, estimated useful life, years	34 years	33 years
Other, estimated useful life, in years	80 years	33 years
Nuclear Fuel [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-1,408	-1,118
Variable Interest Entity, Primary Beneficiary [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total property, plant and equipment	1,873	1,678
Total accumulated depreciation	-257	-175
Regulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-32,628	-31,659
Regulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	82,206	78,272
Regulated Operation [Member] | Electric [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	2 years	2 years
Regulated Operation [Member] | Electric [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	138 years	125 years
Regulated Operation [Member] | Natural Gas [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	2,230	2,138
Regulated Operation [Member] | Natural Gas [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	12 years	12 years
Regulated Operation [Member] | Natural Gas [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	67 years	67 years
Regulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	1,445	1,397
Regulated Operation [Member] | Other Buildings And Improvements [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	9 years	2 years
Regulated Operation [Member] | Other Buildings And Improvements [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	100 years	100 years
Nonregulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-2,196	-1,966
Nonregulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	2,380	6,267
Nonregulated Operation [Member] | Electric [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	1 year	2 years
Nonregulated Operation [Member] | Electric [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	30 years	100 years
Nonregulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	2,498	2,512
Nonregulated Operation [Member] | Other Buildings And Improvements [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	5 years	9 years
Nonregulated Operation [Member] | Other Buildings And Improvements [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution, estimated useful life, in years	50 years	100 years
Duke Energy Carolinas [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Land	403	397
Nuclear fuel	1,676	1,446
Equipment	341	287
Construction in process	2,081	1,741
Other	655	570
Total property, plant and equipment	37,372	34,906
Total accumulated depreciation	-12,700	-11,894
Total net property, plant and equipment	24,672	23,012
Capitalized leases	40	53
Accumulated amortization on capitalized leases	8	4
Capitalized Interest Costs [Abstract]
Capitalized interest	38	41	72
Duke Energy Carolinas [Member] | Nuclear Fuel [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-847	-681
Duke Energy Carolinas [Member] | Regulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-12,700	-11,894
Duke Energy Carolinas [Member] | Regulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	31,751	30,018
Duke Energy Carolinas [Member] | Regulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	465	447
Progress Energy [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Land	704	705
Nuclear fuel	1,190	1,012
Equipment	506	621
Construction in process	1,215	873
Other	756	867
Total property, plant and equipment	38,650	36,480
Total accumulated depreciation	-13,506	-13,098
Total net property, plant and equipment	25,144	23,382
Capitalized leases	315	328
Accumulated amortization on capitalized leases	72	60
Capitalized Interest Costs [Abstract]
Capitalized interest	11	19	41
Progress Energy [Member] | Nuclear Fuel [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-561	-438
Progress Energy [Member] | Regulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-13,506	-13,098
Progress Energy [Member] | Regulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	33,672	31,792
Progress Energy [Member] | Regulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	607	610
Duke Energy Progress [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Land	380	383
Nuclear fuel	1,190	1,012
Equipment	388	357
Construction in process	908	631
Other	439	418
Total property, plant and equipment	24,207	22,273
Total accumulated depreciation	-9,021	-8,623
Total net property, plant and equipment	15,186	13,650
Capitalized leases	146	148
Accumulated amortization on capitalized leases	5
Capitalized Interest Costs [Abstract]
Capitalized interest	10	16	23
Duke Energy Progress [Member] | Nuclear Fuel [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-561	-438
Duke Energy Progress [Member] | Regulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-9,021	-8,623
Duke Energy Progress [Member] | Regulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	20,616	19,190
Duke Energy Progress [Member] | Regulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	286	282
Duke Energy Florida [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Land	324	321
Equipment	118	94
Construction in process	307	238
Other	310	294
Total property, plant and equipment	14,433	13,863
Total accumulated depreciation	-4,478	-4,252
Total net property, plant and equipment	9,955	9,611
Capitalized leases	169	180
Accumulated amortization on capitalized leases	67	57
Capitalized Interest Costs [Abstract]
Capitalized interest	1	3	18
Duke Energy Florida [Member] | Regulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-4,478	-4,252
Duke Energy Florida [Member] | Regulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	13,056	12,601
Duke Energy Florida [Member] | Regulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	318	315
Duke Energy Ohio [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Land	114	137
Equipment	330	317
Construction in process	97	166
Other	214	248
Total property, plant and equipment	7,141	11,143
Total accumulated depreciation	-2,213	-2,908
Generation Facilities To Be Retired Net	9
Total net property, plant and equipment	4,937	8,235
Capitalized leases	98	96
Accumulated amortization on capitalized leases	25	21
Capitalized Interest Costs [Abstract]
Capitalized interest	10	11	13
Duke Energy Ohio [Member] | Regulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-2,213	-2,160
Duke Energy Ohio [Member] | Regulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	3,956	3,925
Duke Energy Ohio [Member] | Regulated Operation [Member] | Natural Gas [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	2,230	2,138
Duke Energy Ohio [Member] | Regulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	200	190
Duke Energy Ohio [Member] | Nonregulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation		-748
Duke Energy Ohio [Member] | Nonregulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution		4,017
Duke Energy Ohio [Member] | Nonregulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution		5
Duke Energy Indiana [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Land	108	105
Equipment	166	146
Construction in process	481	307
Other	195	178
Total property, plant and equipment	13,034	12,489
Total accumulated depreciation	-4,219	-3,913
Total net property, plant and equipment	8,815	8,576
Capitalized leases	30	30
Accumulated amortization on capitalized leases	6	5
Capitalized Interest Costs [Abstract]
Capitalized interest	6	9	39
Duke Energy Indiana [Member] | Regulated Operation [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Total accumulated depreciation	-4,219	-3,913
Duke Energy Indiana [Member] | Regulated Operation [Member] | Electric [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	11,911	11,594
Duke Energy Indiana [Member] | Regulated Operation [Member] | Other Buildings And Improvements [Member]
Public Utilities, Property, Plant and Equipment, Net [Abstract]
Plant - transmission and distribution	$173	$159

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Goodwill By Reportable Operating Segment) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill	$17,192	$17,211
Accumulated impairment charges	-871	-871
Goodwill as adjusted for accumulated impairment charges	16,321	16,340
Foreign exchange and other changes	-19
Regulated Utilities [Member]
Goodwill [Line Items]
Goodwill	15,950	15,950
Goodwill as adjusted for accumulated impairment charges	15,950	15,950
Commercial Power [Member]
Goodwill [Line Items]
Goodwill	935	935
Accumulated impairment charges	-871	-871
Goodwill as adjusted for accumulated impairment charges	64	64
International [Member]
Goodwill [Line Items]
Goodwill	307	326
Goodwill as adjusted for accumulated impairment charges	307	326
Foreign exchange and other changes	-19
Progress Energy [Member]
Goodwill [Line Items]
Goodwill as adjusted for accumulated impairment charges	3,655	3,655
Duke Energy Ohio [Member]
Goodwill [Line Items]
Goodwill	2,324	2,324
Accumulated impairment charges	-1,404	-1,404
Goodwill as adjusted for accumulated impairment charges	920	920
Duke Energy Ohio [Member] | Regulated Utilities [Member]
Goodwill [Line Items]
Goodwill	1,136	1,136
Accumulated impairment charges	-216	-216
Goodwill as adjusted for accumulated impairment charges	920	920
Duke Energy Ohio [Member] | DEO Commercial Power [Member]
Goodwill [Line Items]
Goodwill	1,188	1,188
Accumulated impairment charges	($1,188)	($1,188)

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Schedule of Intangible Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	$317	$487
Accumulated amortization	-54	-109
Total intangible assets, net	263	378
Amortization expense	6	13	14
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2015	11
2016	8
2017	7
2018	7
2019	7
Pretax impairment charge	81	399	666
Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	23	63
Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	97	82
Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	24	180
Accumulated amortization	-15	-73
Wind Development Rights [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	97	86
Accumulated amortization	-14	-12
Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	76	76
Accumulated amortization	-25	-24
Duke Energy Carolinas [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	26	17
Total intangible assets, net	26	17
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge	3		31
Duke Energy Carolinas [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	1	1
Duke Energy Carolinas [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	25	16
Progress Energy [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	76	85
Total intangible assets, net	76	85
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge	-16	380	200
Progress Energy [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	7	21
Progress Energy [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	69	64
Duke Energy Progress [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	72	67
Total intangible assets, net	72	67
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge	-18	22	54
Duke Energy Progress [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	3	3
Duke Energy Progress [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	69	64
Duke Energy Florida [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	4	18
Total intangible assets, net	4	18
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge	2	358	146
Duke Energy Florida [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	4	18
Duke Energy Ohio [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	3	178
Accumulated amortization		-60
Total intangible assets, net	3	118
Amortization expense	2	8	12
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2015	2
2016	1
2017	1
2018	1
2019	1
Pretax impairment charge	94	5	2
Duke Energy Ohio [Member] | Other VIEs [Member]
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge	94
Duke Energy Ohio [Member] | Commercial Power [Member] | Other VIEs [Member]
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Pretax impairment charge	94
Duke Energy Ohio [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount		20
Duke Energy Ohio [Member] | Renewable Energy Certificates [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	3	2
Duke Energy Ohio [Member] | Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount		156
Accumulated amortization		-60
Duke Energy Indiana [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	40	45
Accumulated amortization	-15	-13
Total intangible assets, net	25	32
Amortization expense	1	1	1
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2015	5
2016	3
2017	2
2018	2
2019	2
Pretax impairment charge	0	0	579
Duke Energy Indiana [Member] | Emission Allowances [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	16	21
Duke Energy Indiana [Member] | Gas Coal And Power Contracts [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross carrying amount	24	24
Accumulated amortization	($15)	($13)

Investments_in_Unconsolidated_2

Investments in Unconsolidated Affiliates (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments In Unconsolidated Affiliates [Line Items]
Gain on sale of equity investment	$17	$100	$22
Distributions from equity investments	154	144	183
National Methanol Company [Member] | International Energy [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage	25.00%
Sweetwater I-V [Member] | Commercial Power [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage	50.00%
INDU Solar Holdings [Member] | Commercial Power [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage	50.00%
DS Cornerstone [Member] | Commercial Power [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage	50.00%
Duke American Transmission Co. [Member] | Commercial Power [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage	50.00%
DukeNet [Member]
Investments In Unconsolidated Affiliates [Line Items]
Net sales proceeds		215
Gain on sale of equity investment		$105
DukeNet [Member] | Other [Member]
Investments In Unconsolidated Affiliates [Line Items]
Equity method investment, ownership percentage		50.00%

Investments_in_Unconsolidated_3

Investments in Unconsolidated Affiliates (Investments in Equity Method Unconsolidated Affiliates) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments In Unconsolidated Affiliates [Line Items]
Investments in unconsolidated affiliates	$358	$390
Equity in earnings (losses) of unconsolidated affiliates	130	122	148
Regulated Utilities [Member]
Investments In Unconsolidated Affiliates [Line Items]
Investments in unconsolidated affiliates	3	4
Equity in earnings (losses) of unconsolidated affiliates	-3	-1	-5
International Energy [Member]
Investments In Unconsolidated Affiliates [Line Items]
Investments in unconsolidated affiliates	69	82
Equity in earnings (losses) of unconsolidated affiliates	120	110	134
Commercial Power [Member]
Investments In Unconsolidated Affiliates [Line Items]
Investments in unconsolidated affiliates	258	252
Equity in earnings (losses) of unconsolidated affiliates	10	7	14
Other [Member]
Investments In Unconsolidated Affiliates [Line Items]
Investments in unconsolidated affiliates	28	52
Equity in earnings (losses) of unconsolidated affiliates	$3	$6	$5

Related_Party_Transactions_Oth

Related Party Transactions (Other Revenue and Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Duke Energy Carolinas [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$851	$927	$1,112
Duke Energy Carolinas [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	21	22	21
Duke Energy Carolinas [Member] | Joint Dispatch Agreement (JDA) [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	133	121	18
Related party transaction, expenses from transactions with related party	198	116	91
Progress Energy [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party		96	47
Related party transaction, expenses from transactions with related party	732	290	63
Progress Energy [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	33	34	17
Progress Energy [Member] | Joint Dispatch Agreement (JDA) [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	198	116	91
Related party transaction, expenses from transactions with related party	133	121	18
Duke Energy Progress [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	386	266	254
Duke Energy Progress [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	17	20	8
Duke Energy Progress [Member] | Joint Dispatch Agreement (JDA) [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	198	116	91
Related party transaction, expenses from transactions with related party	133	121	18
Duke Energy Florida [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	346	182	186
Duke Energy Florida [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	16	14	8
Duke Energy Ohio [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	316	347	358
Duke Energy Ohio [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	13	15	15
Duke Energy Ohio [Member] | MarkTo Market Of Commodity Contracts And Sales Of Power [Member] | DECAM [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party			24
Related party transaction, expenses from transactions with related party	24	6
Duke Energy Indiana [Member] | Corporate Governance And Shared Service Expenses [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	384	422	419
Duke Energy Indiana [Member] | Indemnification Coverages [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$11	$14	$8

Related_Party_Transactions_Nar

Related Party Transactions (Narrative) (Details) (USD $)	12 Months Ended	0 Months Ended	12 Months Ended
	Dec. 31, 2014	Jan. 12, 2012	Dec. 31, 2012	Dec. 31, 2013	Apr. 30, 2014
Related Party Transaction [Line Items]
Debt instrument, face amount	$2,922,000,000			$4,023,000,000
DECAM [Member]
Related Party Transaction [Line Items]
Proceeds from Issuance of Debt	400,000,000
Progress Energy [Member]
Related Party Transaction [Line Items]
Intercompany loan payable	835,000,000			1,213,000,000
Duke Energy Progress [Member]
Related Party Transaction [Line Items]
Intercompany loan payable				462,000,000
Debt instrument, face amount	1,350,000,000			800,000,000
Duke Energy Florida [Member]
Related Party Transaction [Line Items]
Intercompany loan payable	84,000,000			181,000,000
Debt instrument, face amount	225,000,000
Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Transfer of Vermillion Generating Station		28,000,000	28,000,000
Intercompany loan payable	491,000,000			43,000,000
Debt instrument, face amount				450,000,000
Duke Energy Ohio [Member] | DECAM [Member]
Related Party Transaction [Line Items]
Intercompany loan payable	459,000,000			43,000,000
Duke Energy Ohio [Member] | Vermillion Generation Station [Member]
Related Party Transaction [Line Items]
Transfer of Vermillion Generating Station			26,000,000
Parent Company [Member]
Related Party Transaction [Line Items]
Debt instrument, face amount	1,000,000,000			1,400,000,000
Duke Energy Indiana [Member]
Related Party Transaction [Line Items]
Transfer of Vermillion Generating Station		26,000,000	26,000,000
Intercompany loan payable	71,000,000
Debt instrument, face amount				500,000,000
Duke Energy Indiana [Member] | Vermillion Generation Station [Member]
Related Party Transaction [Line Items]
Transfer of Vermillion Generating Station			28,000,000
Unsecured Debt [Member] | Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Proceeds from (Repayments of) Debt	-402,000,000
Unsecured Debt [Member] | Parent Company [Member]
Related Party Transaction [Line Items]
Debt instrument, face amount					$1,000,000,000

Derivatives_and_Hedging_Narrat

Derivatives and Hedging (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Derivative [Line Items]
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net	$10
Undesignated commodity contracts latest expiration year	2018
Duke Energy Carolinas [Member]
Derivative [Line Items]
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net	3
Progress Energy [Member]
Derivative [Line Items]
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net	$13

Derivatives_and_Hedging_Notion

Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	dth	GWh
	GWh	dth
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	25,370	71,466
Natural gas (decatherms)	676,000,000	636,000,000
Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	1,027	832
Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	277	34
Interest Rate Contracts [Member] | Cash Flow Hedging [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	750	798
Interest Rate Contracts [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Cash Flow Hedging [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	541	584
Duke Energy Carolinas [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		1,205
Natural gas (decatherms)	35,000,000
Progress Energy [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		925
Natural gas (decatherms)	328,000,000	363,000,000
Duke Energy Progress [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		925
Natural gas (decatherms)	116,000,000	141,000,000
Duke Energy Florida [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Natural gas (decatherms)	212,000,000	222,000,000
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	250
Duke Energy Florida [Member] | Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	250
Duke Energy Ohio [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	19,141	69,362
Natural gas (decatherms)	313,000,000	274,000,000
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	27	27
Duke Energy Ohio [Member] | Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	27	27
Duke Energy Indiana [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		203

Derivatives_and_Hedging_Locati

Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Condensed Consolidated Balance Sheets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$351	$461
Location and fair value amounts of derivatives (Liability)	909	636
Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	210	214
Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	136	233
Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	573	322
Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	319	299
Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	27
Location and fair value amounts of derivatives (Liability)	42	23
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	10	27
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	13	18
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	29	4
Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	341	434
Location and fair value amounts of derivatives (Liability)	867	613
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	4
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	18	201
Location and fair value amounts of derivatives (Liability)		158
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	215
Location and fair value amounts of derivatives (Liability)		131
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	13
Location and fair value amounts of derivatives (Liability)	307	153
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	174
Location and fair value amounts of derivatives (Liability)	253
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	5
Location and fair value amounts of derivatives (Liability)	91	166
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits and Other Liabilities Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	111
Location and fair value amounts of derivatives (Liability)	208
Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	19	2
Duke Energy Carolinas [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	14
Duke Energy Carolinas [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	19	2
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	14	1
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5	1
Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	20
Location and fair value amounts of derivatives (Liability)	371	204
Progress Energy [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	15
Progress Energy [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		5
Progress Energy [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	289	107
Progress Energy [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	82	93
Progress Energy [Member] | Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	5
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Progress Energy [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		4
Progress Energy [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	20
Location and fair value amounts of derivatives (Liability)	370	199
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Location and fair value amounts of derivatives (Liability)		2
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Location and fair value amounts of derivatives (Liability)		1
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		11
Location and fair value amounts of derivatives (Liability)	288	105
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		4
Location and fair value amounts of derivatives (Liability)	80	91
Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		6
Location and fair value amounts of derivatives (Liability)	132	71
Duke Energy Progress [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Duke Energy Progress [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Duke Energy Progress [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	109	41
Duke Energy Progress [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	23	30
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Progress [Member] | Designated As Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		6
Location and fair value amounts of derivatives (Liability)	131	70
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Location and fair value amounts of derivatives (Liability)	108	40
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Location and fair value amounts of derivatives (Liability)	23	29
Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	14
Location and fair value amounts of derivatives (Liability)	239	129
Duke Energy Florida [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	12
Duke Energy Florida [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Duke Energy Florida [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	180	66
Duke Energy Florida [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	59	63
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	14
Location and fair value amounts of derivatives (Liability)	239	129
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		3
Location and fair value amounts of derivatives (Liability)		2
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		9
Location and fair value amounts of derivatives (Liability)	180	64
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Location and fair value amounts of derivatives (Liability)	57	63
Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	341	391
Location and fair value amounts of derivatives (Liability)	473	390
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	204	186
Duke Energy Ohio [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	137	205
Duke Energy Ohio [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	257	199
Duke Energy Ohio [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	216	186
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	341	391
Location and fair value amounts of derivatives (Liability)	473	390
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1	1
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5	4
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	186
Location and fair value amounts of derivatives (Liability)		163
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	28
Location and fair value amounts of derivatives (Liability)	4
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		202
Location and fair value amounts of derivatives (Liability)		130
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	26
Location and fair value amounts of derivatives (Liability)	4
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Location and fair value amounts of derivatives (Liability)		36
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	175
Location and fair value amounts of derivatives (Liability)	252
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		2
Location and fair value amounts of derivatives (Liability)		56
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits and Other Liabilities Assets Held For Sale [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	111
Location and fair value amounts of derivatives (Liability)	207
Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	14	12
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	14	12
Duke Energy Indiana [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	14	12
Duke Energy Indiana [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$14	$12

Derivatives_and_Hedging_Schedu

Derivatives and Hedging (Schedule of Offsetting Assets and Liabilities: Derivatives and Collateral Posted) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	$351	$461
Net amounts recognized on the Consolidated Balance Sheet	110	145
Gross amounts recognized	909	636
Net amounts recognized on the Consolidated Balance Sheet	668	321
Other Current Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	210	214
Gross amounts offset	-153	-179
Net amount subject to master netting	57	35
Net amounts recognized on the Consolidated Balance Sheet	57	35
Other Noncurrent Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	136	233
Gross amounts offset	-88	-138
Net amount subject to master netting	48	95
Amounts not subject to master netting	5	14
Net amounts recognized on the Consolidated Balance Sheet	53	109
Other Current Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	573	322
Gross amounts offset	-213	-192
Net amount subject to master netting	360	130
Amounts not subject to master netting	1	4
Net amounts recognized on the Consolidated Balance Sheet	361	134
Other Noncurrent Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	319	299
Gross amounts offset	-173	-155
Net amount subject to master netting	146	144
Amounts not subject to master netting	16	11
Net amounts recognized on the Consolidated Balance Sheet	162	155
Duke Energy Carolinas [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	19	2
Net amounts recognized on the Consolidated Balance Sheet	19	2
Duke Energy Carolinas [Member] | Other Current Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	14
Net amount subject to master netting	14
Amounts not subject to master netting		1
Net amounts recognized on the Consolidated Balance Sheet	14	1
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	5
Net amount subject to master netting	5
Amounts not subject to master netting		1
Net amounts recognized on the Consolidated Balance Sheet	5	1
Progress Energy [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	2	20
Net amounts recognized on the Consolidated Balance Sheet	4	3
Gross amounts recognized	371	204
Net amounts recognized on the Consolidated Balance Sheet	373	187
Progress Energy [Member] | Other Current Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	2	15
Gross amounts offset	-2	-13
Net amounts recognized on the Consolidated Balance Sheet		2
Progress Energy [Member] | Other Noncurrent Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized		5
Gross amounts offset		-4
Net amounts recognized on the Consolidated Balance Sheet		1
Progress Energy [Member] | Other Current Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	289	107
Gross amounts offset	-17	-17
Net amount subject to master netting	272	90
Net amounts recognized on the Consolidated Balance Sheet	272	90
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	82	93
Gross amounts offset	-8	-10
Net amount subject to master netting	74	83
Amounts not subject to master netting		4
Net amounts recognized on the Consolidated Balance Sheet	74	87
Duke Energy Progress [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized		6
Net amounts recognized on the Consolidated Balance Sheet		1
Gross amounts recognized	132	71
Net amounts recognized on the Consolidated Balance Sheet	132	66
Duke Energy Progress [Member] | Other Current Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized		3
Gross amounts offset		-3
Duke Energy Progress [Member] | Other Noncurrent Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized		3
Gross amounts offset		-3
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	109	41
Gross amounts offset		-3
Net amounts recognized on the Consolidated Balance Sheet	109	38
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	23	30
Gross amounts offset		-3
Net amounts recognized on the Consolidated Balance Sheet	23	27
Duke Energy Florida [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	2	14
Net amounts recognized on the Consolidated Balance Sheet	4	1
Gross amounts recognized	239	129
Net amounts recognized on the Consolidated Balance Sheet	241	116
Duke Energy Florida [Member] | Other Current Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	2	12
Gross amounts offset	-2	-10
Net amounts recognized on the Consolidated Balance Sheet		2
Duke Energy Florida [Member] | Other Noncurrent Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized		2
Gross amounts offset		-2
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	180	66
Gross amounts offset	-17	-15
Net amounts recognized on the Consolidated Balance Sheet	163	51
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	59	63
Gross amounts offset	-8	-7
Net amounts recognized on the Consolidated Balance Sheet	51	56
Duke Energy Ohio [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	341	391
Net amounts recognized on the Consolidated Balance Sheet	49	96
Gross amounts recognized	473	390
Net amounts recognized on the Consolidated Balance Sheet	181	95
Duke Energy Ohio [Member] | Other Current Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	204	186
Gross amounts offset	-179	-165
Net amounts recognized on the Consolidated Balance Sheet	25	21
Duke Energy Ohio [Member] | Other Noncurrent Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	137	205
Gross amounts offset	-114	-132
Net amounts recognized on the Consolidated Balance Sheet	23	73
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	257	199
Gross amounts offset	-222	-173
Net amount subject to master netting	35	26
Amounts not subject to master netting		1
Net amounts recognized on the Consolidated Balance Sheet	35	27
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	216	186
Gross amounts offset	-193	-143
Net amount subject to master netting	23	43
Amounts not subject to master netting		4
Net amounts recognized on the Consolidated Balance Sheet	23	47
Duke Energy Indiana [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	14	12
Net amounts recognized on the Consolidated Balance Sheet	14	12
Duke Energy Indiana [Member] | Other Current Assets [Member]
Offsetting Assets Liabilities [Line Items]
Gross amounts recognized	14	12
Gross amounts offset		-1
Net amounts recognized on the Consolidated Balance Sheet	$14	$11

Derivatives_and_Hedging_Cash_F

Derivatives and Hedging (Cash Flow Hedges - Location and Amount of PreTax Recognized in Comprehensive Income) (Details) (Designated As Hedging Instrument [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI	($39)	$80	($22)
Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI	-39	79	-23
Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recorded in AOCI		1	1
Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI		1	-10
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recorded in AOCI			-11
Progress Energy [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI		1	1
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI			-7
Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recorded in AOCI		1	-1
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recorded in AOCI			-2
Duke Energy Florida [Member] | Commodity Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recorded in AOCI		1	1
Interest Rate Contracts [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	-7	-2	2
Interest Rate Contracts [Member] | Duke Energy Carolinas [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	-3	-3	-3
Interest Rate Contracts [Member] | Progress Energy [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	-13		-14
Interest Rate Contracts [Member] | Duke Energy Progress [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net			-5
Interest Rate Contracts [Member] | Duke Energy Florida [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	-2		-2
Interest Rate Contracts [Member] | Duke Energy Indiana [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net		3	3
Regulatory Asset [Member] | Interest Rate Contracts [Member] | Progress Energy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			-159
Regulatory Asset [Member] | Interest Rate Contracts [Member] | Duke Energy Progress [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			-117
Regulatory Asset [Member] | Interest Rate Contracts [Member] | Duke Energy Florida [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities			($42)

Derivatives_and_Hedging_Undesi

Derivatives and Hedging (Undesignated Contracts - Location and Amount of PreTax Gains and (Losses) Recognized in Income or As Regulatory Assets or Liabilities) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recognized in earnings	($6)	($18)	($8)
Nondesignated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recognized in earnings	-779	-264	-187
Pretax gains (losses) recognized as regulatory assets or liabilities	-252	80	44
Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-268	10	-2
Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	14	15	36
Nondesignated [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings		11	-23
Nondesignated [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings	-44	-200	-194
Nondesignated [Member] | Commodity Contracts [Member] | Income (loss) from Discontinued Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings	-729	-57	40
Nondesignated [Member] | Commodity Contracts [Member] | Other Income And Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings			-2
Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities		55	10
Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	2
Duke Energy Carolinas [Member] | Nondesignated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recognized in earnings		-12	-12
Duke Energy Carolinas [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-19
Duke Energy Carolinas [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings		-12	-12
Progress Energy [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recognized in earnings	-4	-17	-8
Progress Energy [Member] | Nondesignated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recognized in earnings	-48	-206	-466
Pretax gains (losses) recognized as regulatory assets or liabilities	-229	28	-165
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-233	10	-171
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	2
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings		11	-11
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings	-44	-200	-454
Progress Energy [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Other Income And Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings			7
Progress Energy [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	2	18	6
Duke Energy Progress [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recognized in earnings		-13	-6
Duke Energy Progress [Member] | Nondesignated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recognized in earnings	-15	-73	-132
Pretax gains (losses) recognized as regulatory assets or liabilities	-82	7	-49
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-82	-6	-55
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings		11	-11
Duke Energy Progress [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings	-15	-71	-115
Duke Energy Progress [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities		13	6
Duke Energy Florida [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recognized in earnings	-4	-5	-2
Duke Energy Florida [Member] | Nondesignated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recognized in earnings	-33	-134	-341
Pretax gains (losses) recognized as regulatory assets or liabilities	-147	21	-116
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-151	16	-116
Duke Energy Florida [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Fuel Used In Electric Generation And Purchased Power Regulated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings	-29	-129	-339
Duke Energy Florida [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	2	5
Duke Energy Florida [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	2
Duke Energy Ohio [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on interest rate contracts recognized in earnings	-1	-1	-1
Duke Energy Ohio [Member] | Nondesignated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total pretax gains (losses) recognized in earnings	-759	-57	77
Pretax gains (losses) recognized as regulatory assets or liabilities	4	4	1
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	1		2
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	5		-1
Duke Energy Ohio [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Income (loss) from Discontinued Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings	-758	-56	78
Duke Energy Ohio [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-2	4
Duke Energy Indiana [Member] | Nondesignated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-7	50	41
Duke Energy Indiana [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	-16		2
Duke Energy Indiana [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Regulatory Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities	9	16	35
Duke Energy Indiana [Member] | Nondesignated [Member] | Commodity Contracts [Member] | Revenue Regulated Electric [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) on commodity contracts recognized in earnings		1
Duke Energy Indiana [Member] | Nondesignated [Member] | Interest Rate Contracts [Member] | Regulatory Asset [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Pretax gains (losses) recognized as regulatory assets or liabilities		$34	$4

Derivatives_and_Hedging_Deriva

Derivatives and Hedging (Derivative Instruments That Contain Credit-Risk Related Contingent Features and Cash Collateral) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	$845	$525
Collateral already posted	209	135
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	407	205
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	145	30
Derivative, collateral, right to reclaim cash - not offset against net derivative	64	122
Duke Energy Carolinas [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	19
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	19
Progress Energy [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	370	168
Collateral already posted	23	10
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	347	158
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	23	10
Duke Energy Progress [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	131	60
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	131	60
Duke Energy Florida [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	239	108
Collateral already posted	23	10
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	216	98
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	23	10
Duke Energy Ohio [Member]
Schedule Of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	456	355
Collateral already posted	186	125
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered at the end of the reporting period	41	47
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Payables	122	19
Derivative, collateral, right to reclaim cash - not offset against net derivative	64	115
Duke Energy Indiana [Member]
Information Regarding Cash Collateral Under Master Netting Arrangements
Amounts offset against derivative positions on the net condensed Consolidated Balance Sheets, Receivables		1
Derivative, collateral, right to reclaim cash - not offset against net derivative		$1

Investments_in_Debt_and_Equity2

Investments in Debt and Equity Securities (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Trading Securities	$7	$18
Short-term investments		$44

Investments_in_Debt_and_Equity3

Investments in Debt and Equity Securities (Available-For-Sale Investments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	$2,004	$1,884
Gross Unrealized Holding Losses	38	47
Estimated Fair Value	5,901	5,551
NDTF [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,965	1,852
Gross Unrealized Holding Losses	35	36
Estimated Fair Value	5,549	5,133
NDTF [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	136	110
NDTF [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,926	1,813
Gross Unrealized Holding Losses	29	10
Estimated Fair Value	3,650	3,579
NDTF [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	14	8
Gross Unrealized Holding Losses	2	6
Estimated Fair Value	454	400
NDTF [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	5	2
Gross Unrealized Holding Losses		6
Estimated Fair Value	184	160
NDTF [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	19	7
Gross Unrealized Holding Losses	2	12
Estimated Fair Value	978	730
NDTF [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1	22
Gross Unrealized Holding Losses	2	2
Estimated Fair Value	147	154
Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	39	32
Gross Unrealized Holding Losses	3	11
Estimated Fair Value	352	418
Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	15	21
Other Classification [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	34	29
Estimated Fair Value	96	91
Other Classification [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1	1
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	58	99
Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3	2
Gross Unrealized Holding Losses	1	2
Estimated Fair Value	76	79
Other Classification [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	27	17
Other Classification [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	1	8
Estimated Fair Value	80	111
Duke Energy Carolinas [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,119	1,004
Gross Unrealized Holding Losses	23	23
Estimated Fair Value	3,035	2,837
Duke Energy Carolinas [Member] | NDTF [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,119	1,004
Gross Unrealized Holding Losses	22	22
Estimated Fair Value	3,032	2,834
Duke Energy Carolinas [Member] | NDTF [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	51	42
Duke Energy Carolinas [Member] | NDTF [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,102	974
Gross Unrealized Holding Losses	17	6
Estimated Fair Value	2,162	1,964
Duke Energy Carolinas [Member] | NDTF [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	8	5
Gross Unrealized Holding Losses	2	5
Estimated Fair Value	316	274
Duke Energy Carolinas [Member] | NDTF [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses		2
Estimated Fair Value	62	54
Duke Energy Carolinas [Member] | NDTF [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	7	3
Gross Unrealized Holding Losses	1	7
Estimated Fair Value	308	354
Duke Energy Carolinas [Member] | NDTF [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1	22
Gross Unrealized Holding Losses	2	2
Estimated Fair Value	133	146
Duke Energy Carolinas [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	3	3
Duke Energy Carolinas [Member] | Other Classification [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	3	3
Progress Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	849	849
Gross Unrealized Holding Losses	13	14
Estimated Fair Value	2,575	2,358
Progress Energy [Member] | NDTF [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	846	848
Gross Unrealized Holding Losses	13	14
Estimated Fair Value	2,517	2,299
Progress Energy [Member] | NDTF [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	85	68
Progress Energy [Member] | NDTF [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	824	839
Gross Unrealized Holding Losses	12	4
Estimated Fair Value	1,488	1,615
Progress Energy [Member] | NDTF [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	6	3
Gross Unrealized Holding Losses		1
Estimated Fair Value	138	126
Progress Energy [Member] | NDTF [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4	2
Gross Unrealized Holding Losses		4
Estimated Fair Value	122	106
Progress Energy [Member] | NDTF [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	12	4
Gross Unrealized Holding Losses	1	5
Estimated Fair Value	670	376
Progress Energy [Member] | NDTF [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	14	8
Progress Energy [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3	1
Estimated Fair Value	58	59
Progress Energy [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	15	20
Progress Energy [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3	1
Estimated Fair Value	43	39
Duke Energy Progress [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	630	544
Gross Unrealized Holding Losses	11	11
Estimated Fair Value	1,711	1,540
Duke Energy Progress [Member] | NDTF [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	630	544
Gross Unrealized Holding Losses	11	11
Estimated Fair Value	1,711	1,538
Duke Energy Progress [Member] | NDTF [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	50	48
Duke Energy Progress [Member] | NDTF [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	612	535
Gross Unrealized Holding Losses	10	3
Estimated Fair Value	1,171	1,069
Duke Energy Progress [Member] | NDTF [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	5	3
Gross Unrealized Holding Losses		1
Estimated Fair Value	97	80
Duke Energy Progress [Member] | NDTF [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4	2
Gross Unrealized Holding Losses		4
Estimated Fair Value	120	104
Duke Energy Progress [Member] | NDTF [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	9	4
Gross Unrealized Holding Losses	1	3
Estimated Fair Value	265	232
Duke Energy Progress [Member] | NDTF [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	8	5
Duke Energy Progress [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value		2
Duke Energy Progress [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value		2
Duke Energy Florida [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	219	305
Gross Unrealized Holding Losses	2	3
Estimated Fair Value	850	803
Duke Energy Florida [Member] | NDTF [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	216	304
Gross Unrealized Holding Losses	2	3
Estimated Fair Value	806	761
Duke Energy Florida [Member] | NDTF [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	35	20
Duke Energy Florida [Member] | NDTF [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	212	304
Gross Unrealized Holding Losses	2	1
Estimated Fair Value	317	546
Duke Energy Florida [Member] | NDTF [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1
Estimated Fair Value	41	46
Duke Energy Florida [Member] | NDTF [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	2	2
Duke Energy Florida [Member] | NDTF [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3
Gross Unrealized Holding Losses		2
Estimated Fair Value	405	144
Duke Energy Florida [Member] | NDTF [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	6	3
Duke Energy Florida [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3	1
Estimated Fair Value	44	42
Duke Energy Florida [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1	3
Duke Energy Florida [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3	1
Estimated Fair Value	43	39
Duke Energy Indiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	28	24
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	101	94
Duke Energy Indiana [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	28	24
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	101	94
Duke Energy Indiana [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value		1
Duke Energy Indiana [Member] | Other Classification [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	28	24
Estimated Fair Value	71	65
Duke Energy Indiana [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1	1
Estimated Fair Value	$30	$28

Investments_in_Debt_and_Equity4

Investments in Debt and Equity Securities (Maturities) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Debt Instrument [Line Items]
Due in one year or less	$178
Due after one through five years	571
Due after five through ten years	464
Due after ten years	791
Total	2,004
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Due in one year or less	1
Due after one through five years	155
Due after five through ten years	257
Due after ten years	409
Total	822
Progress Energy [Member]
Debt Instrument [Line Items]
Due in one year or less	161
Due after one through five years	350
Due after five through ten years	157
Due after ten years	319
Total	987
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Due in one year or less	14
Due after one through five years	140
Due after five through ten years	109
Due after ten years	227
Total	490
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Due in one year or less	147
Due after one through five years	210
Due after five through ten years	48
Due after ten years	92
Total	497
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Due in one year or less	1
Due after one through five years	17
Due after five through ten years	8
Due after ten years	4
Total	$30

Investments_in_Debt_and_Equity5

Investments in Debt and Equity Securities Investments in Debt and Equity Securities (Realized Gains and Losses) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	$271	$209	$117
Realized losses	105	65	19
Duke Energy Carolinas [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	109	115	89
Realized losses	93	12	6
Progress Energy [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	157	90	34
Realized losses	11	46	18
Duke Energy Progress [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	19	58	21
Realized losses	5	26	8
Duke Energy Florida [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	138	32	13
Realized losses	$5	$20	$9

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$110	$145
Assets, fair value disclosure	6,018	5,712
Derivative liabilities	-668	-321
Net assets, fair value	5,350	5,391
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	49	33
Assets, fair value disclosure	4,327	4,057
Derivative liabilities	-162	11
Net assets, fair value	4,165	4,068
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	24	70
Assets, fair value disclosure	1,498	1,515
Derivative liabilities	-468	-303
Net assets, fair value	1,030	1,212
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	37	42
Assets, fair value disclosure	193	140
Derivative liabilities	-38	-29
Net assets, fair value	155	111
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	3,035	2,837
Derivative liabilities	-19	-2
Net assets, fair value	3,016	2,835
Duke Energy Carolinas [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	2,143	2,047
Net assets, fair value	2,143	2,047
Duke Energy Carolinas [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	738	709
Derivative liabilities	-19
Net assets, fair value	719	709
Duke Energy Carolinas [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	154	81
Derivative liabilities		-2
Net assets, fair value	154	79
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	4	3
Assets, fair value disclosure	2,579	2,353
Derivative liabilities	-373	-187
Net assets, fair value	2,206	2,166
Progress Energy [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	2,013	1,867
Net assets, fair value	2,013	1,867
Progress Energy [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	4	3
Assets, fair value disclosure	566	486
Derivative liabilities	-373	-187
Net assets, fair value	193	299
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		1
Assets, fair value disclosure	1,711	1,543
Derivative liabilities	-132	-66
Net assets, fair value	1,579	1,477
Duke Energy Progress [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	1,322	1,209
Net assets, fair value	1,322	1,209
Duke Energy Progress [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets		1
Assets, fair value disclosure	389	334
Derivative liabilities	-132	-66
Net assets, fair value	257	268
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	4	1
Assets, fair value disclosure	854	801
Derivative liabilities	-241	-116
Net assets, fair value	613	685
Duke Energy Florida [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, fair value disclosure	676	644
Net assets, fair value	676	644
Duke Energy Florida [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	4	1
Assets, fair value disclosure	178	157
Derivative liabilities	-241	-116
Net assets, fair value	-63	41
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	49	96
Derivative liabilities	-181	-95
Net assets, fair value	-132	1
Duke Energy Ohio [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20	50
Derivative liabilities	-117	-1
Net assets, fair value	-97	49
Duke Energy Ohio [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	9	21
Derivative liabilities	-26	-65
Net assets, fair value	-17	-44
Duke Energy Ohio [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	20	25
Derivative liabilities	-38	-29
Net assets, fair value	-18	-4
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	14	12
Net assets, fair value	115	106
Duke Energy Indiana [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net assets, fair value	71	65
Duke Energy Indiana [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net assets, fair value	30	29
Duke Energy Indiana [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	14	12
Net assets, fair value	14	12
NDTF [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3,650	3,579
NDTF [Member] | Equity Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3,493	3,495
NDTF [Member] | Equity Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	6	57
NDTF [Member] | Equity Securities [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	151	27
NDTF [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,899	1,553
NDTF [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	648	402
NDTF [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,251	1,100
NDTF [Member] | Debt Securities [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments		51
NDTF [Member] | Duke Energy Carolinas [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	2,162	1,964
NDTF [Member] | Duke Energy Carolinas [Member] | Equity Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	2,005	1,879
NDTF [Member] | Duke Energy Carolinas [Member] | Equity Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	6	58
NDTF [Member] | Duke Energy Carolinas [Member] | Equity Securities [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	151	27
NDTF [Member] | Duke Energy Carolinas [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	870	870
NDTF [Member] | Duke Energy Carolinas [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	138	168
NDTF [Member] | Duke Energy Carolinas [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	732	651
NDTF [Member] | Duke Energy Carolinas [Member] | Debt Securities [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments		51
NDTF [Member] | Progress Energy [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,488	1,615
NDTF [Member] | Progress Energy [Member] | Equity Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,488	1,615
NDTF [Member] | Progress Energy [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,029	677
NDTF [Member] | Progress Energy [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	510	233
NDTF [Member] | Progress Energy [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	519	444
NDTF [Member] | Duke Energy Progress [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,171	1,069
NDTF [Member] | Duke Energy Progress [Member] | Equity Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	1,171	1,069
NDTF [Member] | Duke Energy Progress [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	540	470
NDTF [Member] | Duke Energy Progress [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	151	137
NDTF [Member] | Duke Energy Progress [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	389	333
NDTF [Member] | Duke Energy Florida [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	317	546
NDTF [Member] | Duke Energy Florida [Member] | Equity Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	317	546
NDTF [Member] | Duke Energy Florida [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	489	214
NDTF [Member] | Duke Energy Florida [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	359	96
NDTF [Member] | Duke Energy Florida [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	130	118
Other Classification [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	96	102
Other Classification [Member] | Equity Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	96	91
Other Classification [Member] | Equity Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments		11
Other Classification [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	263	333
Other Classification [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	41	36
Other Classification [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	217	277
Other Classification [Member] | Debt Securities [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	5	20
Other Classification [Member] | Duke Energy Carolinas [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3	3
Other Classification [Member] | Duke Energy Carolinas [Member] | Debt Securities [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	3	3
Other Classification [Member] | Progress Energy [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	58	58
Other Classification [Member] | Progress Energy [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	15	19
Other Classification [Member] | Progress Energy [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	43	39
Other Classification [Member] | Duke Energy Progress [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments		3
Other Classification [Member] | Duke Energy Progress [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments		3
Other Classification [Member] | Duke Energy Florida [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	44	40
Other Classification [Member] | Duke Energy Florida [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments		2
Other Classification [Member] | Duke Energy Florida [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	44	38
Other Classification [Member] | Duke Energy Indiana [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, equity securities	71	65
Other Classification [Member] | Duke Energy Indiana [Member] | Equity Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, equity securities	71	65
Other Classification [Member] | Duke Energy Indiana [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, debt securities	30	29
Other Classification [Member] | Duke Energy Indiana [Member] | Debt Securities [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, debt securities	$30	$29

Fair_Value_Measurements_Reconc

Fair Value Measurements (Reconciliation of Assets and Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$111	$13	$85
Amounts Acquired in Progress Energy Merger			-30
Total pretax gains (losses) included in earnings	-7	-42	8
Total pretax gains (losses) included in comprehensive income			13
Purchases	84	30	36
Sales	-58	-6	-2
Issuances		-11	-15
Settlements	-54	16	-87
Transfers in and/or out of level 3	74	86
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	6	86
Total gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability	5	3	5
Ending balance	155	111	13
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	13	-85	-39
Amounts Acquired in Progress Energy Merger			-30
Total pretax gains (losses) included in earnings	-7	-42	8
Purchases	50	21	22
Issuances		-11	-15
Settlements	-54	25	-32
Total Gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability	-9	-3	1
Ending balance	-1	13	-85
Pretax amounts included in the Consolidated Statements of Comprehensive Income related to Level 3 measurements outstanding at end of period	-14
Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	98	98	124
Total pretax gains (losses) included in comprehensive income			13
Purchases	34	9	14
Sales	-58	-6	-2
Settlements		-9	-55
Transfers in and/or out of level 3	68
Total gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability	14	6	4
Ending balance	156	98	98
Derivative [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Pretax amounts included in the Consolidated Statements of Comprehensive Income related to Level 3 measurements outstanding at end of period	-14
Duke Energy Carolinas [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	79	60	65
Total pretax gains (losses) included in comprehensive income			2
Purchases	34	9	14
Sales	-43		-14
Issuances		-6	-2
Settlements	2	10	-9
Transfers in and/or out of level 3	68
Total gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability	14	6	4
Ending balance	154	79	60
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	-2	-12
Sales			-14
Settlements	2	10	2
Ending balance		-2	-12
Duke Energy Carolinas [Member] | Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	81	72	65
Total pretax gains (losses) included in comprehensive income			2
Purchases	34	9	14
Sales	-43
Issuances		-6	-2
Settlements			-11
Transfers in and/or out of level 3	68
Total gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability	14	6	4
Ending balance	154	81	72
Progress Energy [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3		34
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance		-38	-24
Total pretax gains (losses) included in earnings			1
Issuances		-10	16
Settlements			4
Total Gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability		-6	-3
Ending balance			-38
Duke Energy Progress [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3		34
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance		-38	-24
Total pretax gains (losses) included in earnings			1
Issuances		-10	16
Settlements			4
Total Gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability		-6	-3
Ending balance			-38
Duke Energy Ohio [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	6	43
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	-4	-6	-3
Total pretax gains (losses) included in earnings	-9	-42	-3
Purchases	1	1
Settlements	-13		1
Total Gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability	1		-1
Ending balance	-18	-4	-6
Duke Energy Indiana [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	12	10	4
Total pretax gains (losses) included in earnings	3	8	36
Purchases	49	20
Issuances			-22
Settlements	-41	-30	-52
Total Gains (losses) included on the Consolidated Balance Sheet as regulatory asset or liability	-9	4
Ending balance	$14	$12	$10

Fair_Value_Measurements_Quanti

Fair Value Measurements (Quantitative Level 3 Fair Value Disclosure) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	($1)	$13	($85)	($39)
Commodity Natural Gas Hedges [Member] | Discounted Cash Flow [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	-5	-2
Commodity Natural Gas Hedges [Member] | Discounted Cash Flow [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per MMBtu	2.12	3.07
Commodity Natural Gas Hedges [Member] | Discounted Cash Flow [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per MMBtu	4.35	5.37
FERC Mitigation Power Sale Agreements [Member] | Discounted Cash Flow [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)		-2
FERC Mitigation Power Sale Agreements [Member] | Discounted Cash Flow [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh		25.79
FERC Mitigation Power Sale Agreements [Member] | Discounted Cash Flow [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh		52.38
Financial Transmission Rights [Member] | Market Approach Valuation Technique [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	14	12
Financial Transmission Rights [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh	-1.92	-0.3
Financial Transmission Rights [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh	9.86	13.8
Commodity Power Contracts [Member] | Discounted Cash Flow [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	-1	23
Commodity Power Contracts [Member] | Discounted Cash Flow [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh	25.16	20.77
Commodity Power Contracts [Member] | Discounted Cash Flow [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh	51.75	58.9
Commodity Capacity Option Contracts [Member] | Discounted Cash Flow [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	2	4
Commodity Capacity Option Contracts [Member] | Discounted Cash Flow [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Mwd	21	30.4
Commodity Capacity Option Contracts [Member] | Discounted Cash Flow [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per Mwd	109	165.1
Derivative Financial Instruments Liabilities Reserves [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	-11	-22
Duke Energy Carolinas [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)		-2	-12
Duke Energy Carolinas [Member] | FERC Mitigation Power Sale Agreements [Member] | Discounted Cash Flow [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)		-2
Duke Energy Carolinas [Member] | FERC Mitigation Power Sale Agreements [Member] | Discounted Cash Flow [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh		25.79
Duke Energy Carolinas [Member] | FERC Mitigation Power Sale Agreements [Member] | Discounted Cash Flow [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh		52.38
Progress Energy [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)			-38	-24
Duke Energy Progress [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)			-38	-24
Duke Energy Ohio [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	-18	-4	-6	-3
Duke Energy Ohio [Member] | Commodity Natural Gas Hedges [Member] | Discounted Cash Flow [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	-5	-2
Duke Energy Ohio [Member] | Commodity Natural Gas Hedges [Member] | Discounted Cash Flow [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per MMBtu	2.12	3.07
Duke Energy Ohio [Member] | Commodity Natural Gas Hedges [Member] | Discounted Cash Flow [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair Value Inputs Price Per MMBtu	4.35	5.37
Duke Energy Ohio [Member] | Commodity Power Contracts [Member] | Discounted Cash Flow [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	-6	18
Duke Energy Ohio [Member] | Commodity Power Contracts [Member] | Discounted Cash Flow [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh	25.25	20.77
Duke Energy Ohio [Member] | Commodity Power Contracts [Member] | Discounted Cash Flow [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price per MWh	51.75	58.9
Duke Energy Ohio [Member] | Derivative Financial Instruments Liabilities Reserves [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	-7	-20
Duke Energy Indiana [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	14	12	10	4
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | RTO Market Pricing [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	$14	$12
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | RTO Market Pricing [Member] | Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price FTR	-1.92	-0.3
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | RTO Market Pricing [Member] | Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price FTR	9.86	13.8

Fair_Value_Measurements_Additi

Fair Value Measurements (Additional Fair Value Disclosure) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$40,020	$40,256
Long-term debt, fair value	44,566	42,592
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	8,391	8,436
Long-term debt, fair value	9,626	9,123
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	14,754	14,115
Long-term debt, fair value	16,951	15,234
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	6,201	5,235
Long-term debt, fair value	6,696	5,323
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	4,860	4,886
Long-term debt, fair value	5,767	5,408
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	1,766	2,188
Long-term debt, fair value	1,970	2,237
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,791	3,796
Long-term debt, fair value	$4,456	$4,171

Variable_Interest_Entities_Nar

Variable Interest Entities (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Impairment charges	$81	$399	$666
Cinergy Receivables [Member]
Variable Interest Entity [Line Items]
Minimum Equity Balance required by Cinergy Receivables	3
Line of credit facility, expiration date	1-Nov-16
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Percent of proceeds received as cash	75.00%
Percent of proceeds received as subordinated note	25.00%
Duke Energy Carolinas [Member]
Variable Interest Entity [Line Items]
Impairment charges	3		31
Duke Energy Carolinas [Member] | DERF [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Line of credit facility, expiration date	1-Oct-16
Duke Energy Progress [Member]
Variable Interest Entity [Line Items]
Impairment charges	-18	22	54
Duke Energy Progress [Member] | DEPR [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Line of credit facility, expiration date	1-Dec-16
Duke Energy Florida [Member]
Variable Interest Entity [Line Items]
Impairment charges	2	358	146
Duke Energy Ohio [Member]
Variable Interest Entity [Line Items]
Impairment charges	94	5	2
Duke Energy Ohio [Member] | Cinergy Receivables [Member]
Variable Interest Entity [Line Items]
Fixed rate used when selling receivables	1.00%
Duke Energy Ohio [Member] | Other VIEs [Member]
Variable Interest Entity [Line Items]
Impairment charges	94
Duke Energy Ohio [Member] | Other VIEs [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Ownership interest in OVEC	9.00%
Duke Energy Indiana [Member]
Variable Interest Entity [Line Items]
Impairment charges	$0	$0	$579
Duke Energy Indiana [Member] | Cinergy Receivables [Member]
Variable Interest Entity [Line Items]
Fixed rate used when selling receivables	1.00%

Variable_Interest_Entities_Con

Variable Interest Entities (Consolidated VIEs) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	$1,973	$1,719
Other current assets	1,837	1,821
Investments and other assets	3,008	3,432
Total property, plant and equipment	104,861	103,115
Accumulated depreciation and amortization	-34,824	-33,625
Other deferred debits	171	181
Accounts payable	2,271	2,391
Current maturities of long-term debt	2,807	2,104
Other current liabilities	2,188	1,996
Long-Term debt	37,213	38,152
Deferred income taxes	13,423	12,097
Asset retirement obligations	8,466	4,950
Other liabilities	1,675	1,749
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	1,973	1,719
Other current assets	74	101
Investments and other assets	50	80
Total property, plant and equipment	1,873	1,680
Accumulated depreciation and amortization	-255	-175
Other deferred debits	36	36
Total assets	3,751	3,441
Accounts payable	3	2
Taxes accrued	6	10
Current maturities of long-term debt	84	80
Other current liabilities	21	27
Long-Term debt	2,234	1,966
Deferred income taxes	283	290
Asset retirement obligations	29	26
Other liabilities	38	31
Total liabilities	2,698	2,432
Net assets of consolidated VIEs	1,053	1,009
Duke Energy Carolinas [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	647	673
Other current assets	77	309
Investments and other assets	959	1,000
Total property, plant and equipment	37,372	34,906
Accumulated depreciation and amortization	-12,700	-11,894
Other deferred debits	42	46
Accounts payable	709	701
Current maturities of long-term debt	507	47
Other current liabilities	434	393
Long-Term debt	7,584	8,089
Deferred income taxes	5,812	5,706
Asset retirement obligations	3,428	1,594
Other liabilities	642	676
Duke Energy Progress [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	436	417
Other current assets	384	296
Investments and other assets	412	443
Total property, plant and equipment	24,207	22,273
Accumulated depreciation and amortization	-9,021	-8,623
Other deferred debits	34	32
Accounts payable	481	420
Current maturities of long-term debt	945	174
Other current liabilities	409	392
Long-Term debt	5,256	5,061
Deferred income taxes	2,908	2,557
Asset retirement obligations	3,905	1,729
Other liabilities	168	222
Duke Energy Florida [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	305
Other current assets	521	182
Investments and other assets	204	252
Total property, plant and equipment	14,433	13,863
Accumulated depreciation and amortization	-4,478	-4,252
Other deferred debits	39	44
Accounts payable	365	333
Current maturities of long-term debt	562	11
Other current liabilities	586	445
Long-Term debt	4,298	4,875
Deferred income taxes	2,452	1,829
Asset retirement obligations	806	833
Other liabilities	158	255
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	647	673
Other deferred debits		1
Total assets	647	674
Long-Term debt	400	400
Other liabilities		1
Total liabilities	400	401
Net assets of consolidated VIEs	247	273
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	436	416
Other deferred debits		1
Total assets	436	417
Long-Term debt	300	300
Total liabilities	300	300
Net assets of consolidated VIEs	136	117
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	305
Total assets	305
Long-Term debt	225
Total liabilities	225
Net assets of consolidated VIEs	80
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	547	595
Total assets	547	595
Long-Term debt	325	325
Total liabilities	325	325
Net assets of consolidated VIEs	222	270
Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	20	18
Other current assets	68	89
Investments and other assets	25	29
Total property, plant and equipment	1,855	1,662
Accumulated depreciation and amortization	-250	-170
Other deferred debits	34	34
Total assets	1,752	1,662
Accounts payable	3	2
Taxes accrued	6	10
Current maturities of long-term debt	68	66
Other current liabilities	16	17
Long-Term debt	967	907
Deferred income taxes	283	290
Asset retirement obligations	29	26
Other liabilities	34	17
Total liabilities	1,406	1,335
Net assets of consolidated VIEs	346	327
Other VIEs [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	18	17
Other current assets	6	12
Investments and other assets	25	51
Total property, plant and equipment	18	18
Accumulated depreciation and amortization	-5	-5
Other deferred debits	2
Total assets	64	93
Current maturities of long-term debt	16	14
Other current liabilities	5	10
Long-Term debt	17	34
Other liabilities	4	13
Total liabilities	42	71
Net assets of consolidated VIEs	$22	$22

Variable_Interest_Entities_Sch

Variable Interest Entities (Schedule of Accounts Receivable Securitizations)(Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Variable Interest Entity [Line Items]
Debt instrument, face amount	$2,922,000,000	$4,023,000,000
Duke Energy Progress [Member]
Variable Interest Entity [Line Items]
Debt instrument, face amount	1,350,000,000	800,000,000
Duke Energy Florida [Member]
Variable Interest Entity [Line Items]
Debt instrument, face amount	225,000,000
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Debt instrument, face amount	400,000,000
Line of credit facility, expiration date	1-Oct-16
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Debt instrument, face amount	300,000,000
Line of credit facility, expiration date	1-Dec-16
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Debt instrument, face amount	$225,000,000
Line of credit facility, expiration date	1-Mar-17

Variable_Interest_Entities_Sch1

Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Impairment charges	$81	$399	$666
Investments in equity method unconsolidated affiliates	358	390
Investments and other assets	3,008	3,432
Other current liabilities	2,188	1,996
Other liabilities	31,364	26,575
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	188	213
Intangibles, net		96
Investments and other assets	4	4
Total assets	192	313
Other current liabilities	3	3
Other liabilities	14	15
Total liabilities	17	18
Net assets of non-consolidated VIEs	175	295
Renewables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	150	153
Total assets	150	153
Net assets of non-consolidated VIEs	150	153
Other VIEs [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in equity method unconsolidated affiliates	38	60
Intangibles, net		96
Investments and other assets	4	4
Total assets	42	160
Other current liabilities	3	3
Other liabilities	14	15
Total liabilities	17	18
Net assets of non-consolidated VIEs	25	142
Duke Energy Ohio [Member]
Variable Interest Entity [Line Items]
Impairment charges	94	5	2
Investments and other assets	23	232
Other current liabilities	66	110
Other liabilities	2,281	2,546
Duke Energy Ohio [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Receivables	91	114
Intangibles, net		96
Total assets	91	210
Net assets of non-consolidated VIEs	91	210
Duke Energy Ohio [Member] | Other VIEs [Member]
Variable Interest Entity [Line Items]
Impairment charges	94
Duke Energy Indiana [Member]
Variable Interest Entity [Line Items]
Impairment charges	0	0	579
Investments and other assets	251	269
Other current liabilities	98	88
Other liabilities	2,730	2,334
Duke Energy Indiana [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Receivables	113	143
Total assets	113	143
Net assets of non-consolidated VIEs	$113	$143

Variable_Interest_Entities_Fai

Variable Interest Entities (Fair Value Assumptions)(Details) (Variable Interest Entity, Not Primary Beneficiary [Member], Cinergy Receivables [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Duke Energy Ohio [Member]
Variable Interest Entity [Line Items]
Anticipated credit loss ratio	0.60%	0.60%
Discount rate	1.20%	1.20%
Receivable turnover rate	12.80%	12.80%
Duke Energy Indiana [Member]
Variable Interest Entity [Line Items]
Anticipated credit loss ratio	0.30%	0.30%
Discount rate	1.20%	1.20%
Receivable turnover rate	10.50%	10.30%

Variable_Interest_Entities_Rec

Variable Interest Entities (Receivables Sold)(Details) (Variable Interest Entity, Not Primary Beneficiary [Member], Cinergy Receivables [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Duke Energy Ohio [Member]
Variable Interest Entity [Line Items]
Receivables sold	$273	$290
Less: retained interests	91	114
Net receivables sold	182	176
Duke Energy Indiana [Member]
Variable Interest Entity [Line Items]
Receivables sold	310	340
Less: retained interests	113	143
Net receivables sold	$197	$197

Variable_Interest_Entities_Sal

Variable Interest Entities (Sales and Cash Flows)(Details) (Variable Interest Entity, Not Primary Beneficiary [Member], Cinergy Receivables [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Duke Energy Ohio [Member]
Variable Interest Entity [Line Items]
Receivables sold	$2,246	$2,251	$2,154
Loss recognized on sale	11	12	13
Cash proceeds from receivables sold	2,261	2,220	2,172
Collection fees received	1	1	1
Return received on retained interests	4	5	5
Duke Energy Indiana [Member]
Variable Interest Entity [Line Items]
Receivables sold	2,913	2,985	2,773
Loss recognized on sale	11	11	12
Cash proceeds from receivables sold	2,932	2,944	2,784
Collection fees received	1	1	1
Return received on retained interests	$6	$6	$7

Common_Stock_Details

Common Stock (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Line Items]
Income from continuing operations attributable to Duke Energy common stockholders, as adjusted for participating securities - basic and diluted									$2,451	$2,574	$1,593
Average shares, basic									707	706	574
Average shares, diluted									707	706	575
EPS, basic	$0.14	$1.25	$1.02	$1.05	$0.96	$1.33	$0.40	$0.93	$3.46	$3.64	$2.77
EPS, diluted	$0.14	$1.25	$1.02	$1.05	$0.96	$1.33	$0.40	$0.93	$3.46	$3.63	$2.77
Common Class A [Member]
Earnings Per Share [Line Items]
Income from continuing operations attributable to Duke Energy common stockholders, as adjusted for participating securities - basic and diluted									$2,446	$2,565	$1,588
Average shares, basic									707	706	574
Stock options, performance and restricted stock											1
Average shares, diluted									707	706	575
EPS, basic									$3.46	$3.64	$2.77
EPS, diluted									$3.46	$3.63	$2.77
Number of stock options and performance and unvested stock awards excluded from the dilutive securities calculation									2	2	1
Dividends declared per share									$3.15	$3.09	$3.03

Severance_Narrative_Details

Severance (Narrative) (Details) (USD $)	12 Months Ended	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Nov. 30, 2011	Dec. 31, 2013	Dec. 31, 2014
		Employees		Employees
Restructuring Cost and Reserve [Line Items]
Voluntary opportunity cost deferral	$101
2011 Severance Plan [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees that accepted the termination benefits		1,100
Duke Energy Carolinas [Member]
Restructuring Cost and Reserve [Line Items]
Voluntary opportunity cost deferral	101
Duke Energy Florida [Member] | Crystal River Unit 3 2013 Severance Plan [Member]
Restructuring Cost and Reserve [Line Items]
Number of eligible employees	600
Deferred severance costs			$26
Duke Energy Ohio [Member] | Midwest Commercial Generation Involuntary Severance Plan [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees that accepted the termination benefits				50

Severance_Expenses_Details

Severance (Expenses) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Severance expense	$34	$201
COBRA and healthcare expense reimbursement	2	19
Accelerated stock compensation expense	5	14
Duke Energy Carolinas [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	8	63
Progress Energy [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	19	82
Duke Energy Progress [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	14	55
Duke Energy Florida [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	5	27
Duke Energy Ohio [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	2	21
Duke Energy Ohio [Member] | Midwest Commercial Generation Involuntary Severance Plan [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense			6
Duke Energy Indiana [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	$2	$18

Severance_Rollforward_Details

Severance (Rollforward) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Restructuring Reserve [Roll Forward]
Balance, beginning of period	$64
Provision/adjustments	5
Cash reductions	-41
Balance, end of period	28
Duke Energy Carolinas [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	5
Provision/adjustments	2
Cash reductions	-5
Balance, end of period	2
Progress Energy [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	44
Provision/adjustments	-10
Cash reductions	-16
Balance, end of period	18
Duke Energy Progress [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	11
Cash reductions	-10
Balance, end of period	1
Duke Energy Florida [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	24
Provision/adjustments	-1
Cash reductions	-6
Balance, end of period	17
Duke Energy Ohio [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period	2
Provision/adjustments	5
Cash reductions	-1
Balance, end of period	$6

StockBased_Compensation_Narrat

Stock-Based Compensation (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated fair value of stock based compensation awards allocated to purchase price	$62
Shares reserved for awards to employees and outside directors	25
Shares to be issued under various stock-based awards other than options and stock appreciation rights	6.25
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum option term, years	10 years
Restricted Stock Units Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grant date fair value of shares vested	52	50	34
Unrecognized compensation cost	18
Unrecognized compensation cost, period of recognition, years	1 year 10 months 0 days
Restricted Stock Units Awards [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grant date fair value of shares vested	27	42	56
Unrecognized compensation cost	$21
Unrecognized compensation cost, period of recognition, years	1 year 9 months 0 days
Risk Free Interest Rate	0.70%
Expected Volatility Rate	13.50%

StockBased_Compensation_Schedu

Stock-Based Compensation (Schedule of Stock-Based Compensation Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	$38	$52	$48
Pretax stock-based compensation expense	61	85	78
Tax benefit associated with stock-based compensation expense	23	33	30
Stock-based compensation costs capitalized	4	3	2
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense		2	2
Restricted Stock Units Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	39	49	43
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	22	34	33
Duke Energy Carolinas [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	12	13	12
Progress Energy [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	14	23	25
Duke Energy Progress [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	9	14	16
Duke Energy Florida [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	5	9	9
Duke Energy Ohio [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	5	4	4
Duke Energy Indiana [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	$3	$4	$4

StockBased_Compensation_Stock_

Stock-Based Compensation (Stock Options) (Details) (USD $)	12 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Option Activity, Options [Roll Forward]
Outstanding at beginning of period	793
Granted		310	340
Exercised	-420
Outstanding at end of period	373	793
Exercisable at end of period	53
Options expected to vest	320
Stock Option Activity, Weighted Average Exercise Price [Roll Forward]
Weighted average exercise price of options outstanding at beginning of period	$61
Exercised	$59
Weighted average exercise price of options outstanding end of period	$64	$61
Weighted average exercise price of options exercisable at end of period	$46
Weighted average exercise price of options expected to vest	$67
Weighted-Average Remaining Life [Abstract]
Weighted average remaining life of options outstanding at end of period, years	6 years 10 months 0 days
Weighted average remaining life of options exercisable at end of period, years	1 year 0 months 0 days
Weighted average remaining life of options expected to vest, years	7 years 10 months 0 days
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value of options outstanding at end of period	$7
Aggregate intrinsic value of options exercisable at end of period	2
Aggregate intrinsic value of options expected to vest	5
Schedule Of Information Related To Stock Options [Abstract]
Intrinsic value of options exercised	6	26	17
Tax benefit related to options exercised	2	10	7
Cash received from options exercised	$25	$9	$21
Stock options granted		310	340

StockBased_Compensation_Summar

Stock-Based Compensation (Summary of Stock Awards Outstanding) (Details) (USD $)	12 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock Units Awards [Member]
Schedule Of Shares Awarded [Abstract]
Shares awarded (in thousands)	557	612	443
Fair value	$40	$42	$28
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period	1,400
Granted	557	612	443
Vested	-832
Forfeited	-45
Outstanding at end of period	1,080	1,400
Stock awards expected to vest	1,057
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average fair value at beginning of period	$66
Granted	$71
Vested	$62
Forfeited	$68
Weighted average fair value at end of period	$69	$66
Weighted average fair value of awards expected to vest	$69
Performance Awards [Member]
Schedule Of Shares Awarded [Abstract]
Shares awarded (in thousands)	542	633	352
Fair value	$19	$28	$19
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period	1,822
Granted	542	633	352
Vested	-524
Forfeited	-213
Outstanding at end of period	1,627	1,822
Stock awards expected to vest	1,418
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average fair value at beginning of period	$46
Granted	$34
Vested	$52
Forfeited	$37
Weighted average fair value at end of period	$42	$46
Weighted average fair value of awards expected to vest	$42

Employee_Benefit_Plans_Narrati

Employee Benefit Plans (Narrative) (Details) (USD $)	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Maximum years of participation	35 years	35 years
Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of securities on loan		383	$43
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Qualified Pension Plans [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Master trust allocation percentage		98.00%
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		13 years
Other Post-Retirement Benefit Plans [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Master trust allocation percentage		2.00%
Duke Energy Carolinas [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Duke Energy Carolinas [Member] | Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Progress Energy [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Progress Energy [Member] | Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		13 years
Duke Energy Progress [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Duke Energy Progress [Member] | Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		12 years
Duke Energy Florida [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Duke Energy Florida [Member] | Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		17 years
Duke Energy Ohio [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Duke Energy Ohio [Member] | Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Duke Energy Indiana [Member] | Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years
Duke Energy Indiana [Member] | Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Average remaining service period, in years		9 years

Employee_Benefit_Plans_Contrib

Employee Benefit Plans (Contributions to Defined Benefit Pension Plans) (Details) (Qualified Pension Plans [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		$250	$304
Anticipated contribution	302
Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Anticipated contribution	91
Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		250	346
Anticipated contribution	83
Duke Energy Progress [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		63	141
Anticipated contribution	42
Duke Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		133	128
Anticipated contribution	40
Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Anticipated contribution	8
Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Anticipated contribution	$19

Employee_Benefit_Plans_Compone

Employee Benefit Plans (Components of Net Periodic Pension Costs) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Qualified Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$135	$167	$122
Interest cost on projected benefit obligation	344	320	307
Expected return on plan assets	-511	-549	-472
Amortization of actuarial loss (gain)	150	244	144
Amortization of prior service cost (credit)	-15	-11	10
Other	8	7	6
Net periodic costs	111	178	117
Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	41	49	35
Interest cost on projected benefit obligation	85	80	90
Expected return on plan assets	-132	-148	-146
Amortization of actuarial loss (gain)	36	60	45
Amortization of prior service cost (credit)	-8	-6	1
Other	2	2	2
Net periodic costs	24	37	27
Qualified Pension Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	40	60	63
Interest cost on projected benefit obligation	112	116	127
Expected return on plan assets	-173	-199	-188
Amortization of actuarial loss (gain)	68	101	93
Amortization of prior service cost (credit)	-3	-4	9
Other	3	2	2
Net periodic costs	47	76	106
Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	21	22	25
Interest cost on projected benefit obligation	54	50	58
Expected return on plan assets	-85	-94	-96
Amortization of actuarial loss (gain)	32	46	37
Amortization of prior service cost (credit)	-2	-1	8
Other	1	1	1
Net periodic costs	21	24	33
Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	20	30	30
Interest cost on projected benefit obligation	57	53	56
Expected return on plan assets	-85	-87	-81
Amortization of actuarial loss (gain)	32	49	48
Amortization of prior service cost (credit)	-1	-2	-1
Other	1	1	1
Net periodic costs	24	44	53
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	4	6	6
Interest cost on projected benefit obligation	20	21	31
Expected return on plan assets	-27	-31	-45
Amortization of actuarial loss (gain)	4	13	10
Amortization of prior service cost (credit)			1
Net periodic costs	1	9	3
Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	9	11	9
Interest cost on projected benefit obligation	29	28	30
Expected return on plan assets	-41	-46	-46
Amortization of actuarial loss (gain)	13	24	15
Amortization of prior service cost (credit)		1	1
Other	1	1
Net periodic costs	11	19	9
Non-Qualified Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	3	3	2
Interest cost on projected benefit obligation	14	13	12
Amortization of actuarial loss (gain)	3	5	4
Amortization of prior service cost (credit)	-1	-1	1
Net periodic costs	19	20	19
Non-Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	1	1	1
Net periodic costs	1	1	1
Non-Qualified Pension Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	2
Interest cost on projected benefit obligation	5	7	8
Amortization of actuarial loss (gain)	2	3	5
Amortization of prior service cost (credit)	-1	-1	-1
Net periodic costs	7	10	14
Non-Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	1
Interest cost on projected benefit obligation	1	1	1
Amortization of actuarial loss (gain)		1	1
Net periodic costs	2	3	3
Non-Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost on projected benefit obligation	2	1	2
Amortization of actuarial loss (gain)		1
Net periodic costs	2	2	2
Non-Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net periodic costs	0	0	0
Non-Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net periodic costs	0	0	0
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	10	24	16
Interest cost on projected benefit obligation	49	68	56
Expected return on plan assets	-13	-14	-17
Amortization of actuarial loss (gain)	39	52	14
Amortization of prior service cost (credit)	-125	-41	-8
Amortization of net transition liability			10
Other			9
Net periodic costs	-40	89	80
Other Post-Retirement Benefit Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	2	2	2
Interest cost on projected benefit obligation	12	13	15
Expected return on plan assets	-9	-11	-10
Amortization of actuarial loss (gain)	3	3	3
Amortization of prior service cost (credit)	-11	-7	-5
Amortization of net transition liability			7
Other			1
Net periodic costs	-3	0	13
Other Post-Retirement Benefit Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	4	18	17
Interest cost on projected benefit obligation	22	41	43
Expected return on plan assets			-2
Amortization of actuarial loss (gain)	42	57	35
Amortization of prior service cost (credit)	-95	-30
Amortization of net transition liability			4
Other			5
Net periodic costs	-27	86	102
Other Post-Retirement Benefit Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	9	8
Interest cost on projected benefit obligation	11	22	23
Amortization of actuarial loss (gain)	31	34	20
Amortization of prior service cost (credit)	-73	-20
Other			2
Net periodic costs	-30	45	53
Other Post-Retirement Benefit Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	3	7	7
Interest cost on projected benefit obligation	12	16	18
Expected return on plan assets			-2
Amortization of actuarial loss (gain)	10	16	12
Amortization of prior service cost (credit)	-21	-6
Amortization of net transition liability			3
Other			1
Net periodic costs	4	33	39
Other Post-Retirement Benefit Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost		1	1
Interest cost on projected benefit obligation	2	2	3
Expected return on plan assets		-1	-1
Amortization of actuarial loss (gain)	-2	-1	-2
Amortization of prior service cost (credit)		-1	-1
Net periodic costs	0	0	0
Other Post-Retirement Benefit Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	1
Interest cost on projected benefit obligation	5	5	6
Expected return on plan assets	-1	-1	-1
Amortization of actuarial loss (gain)		1
Net periodic costs	$5	$6	$6

Employee_Benefit_Plans_Amounts

Employee Benefit Plans (Amounts Recognized in Accumulated Other Comprehensive Income and Regulatory Assets and Liabilities) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax benefit (expense)			$17		$9
Net amount recognized in accumulated other comprehensive (income) loss	-4	[1]	-38	[1]	-19	[1]
Progress Energy [Member]
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss	-9		-9		2
Duke Energy Ohio [Member]
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss			-1		-27
Qualified Pension Plans [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	112		-788
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax benefit (expense)	-10		18
Actuarial (gains) losses arising during the year	29		-33
Prior year service cost (credit) arising during the year			-1
Amortization of prior year actuarial gains (losses)	-9		-15
Reclassification of actuarial gains (losses) to regulatory assets	-1		3
Net amount recognized in accumulated other comprehensive (income) loss	9		-28
Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	30		-205
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss	0		0
Qualified Pension Plans [Member] | Progress Energy [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	-73		-253
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax benefit (expense)	-2
Actuarial (gains) losses arising during the year			-2
Amortization of prior year actuarial gains (losses)			-3
Net amount recognized in accumulated other comprehensive (income) loss	-2		-5
Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	-17		-109
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss	0		0
Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	11		-146
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss	0		0
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	17		-96
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss	0		0
Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	4		-99
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Net amount recognized in accumulated other comprehensive (income) loss	0		0
Non Qualified Pension Plans [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	44		-14
Regulatory liabilities, net increase (decrease)	-7		5
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax benefit (expense)	4
Actuarial (gains) losses arising during the year	-9		2
Prior year service cost (credit) arising during the year			-1
Net amount recognized in accumulated other comprehensive (income) loss	-5		1
Non Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	1		1
Non Qualified Pension Plans [Member] | Progress Energy [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	14		-16
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax benefit (expense)	5		1
Actuarial (gains) losses arising during the year	-11		-5
Net amount recognized in accumulated other comprehensive (income) loss	-6		-4
Non Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	4		-4
Non Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	19		-3
Non Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	1
Non Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	2		-2
Other Post-Retirement Benefit Plans [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	162		-683
Regulatory liabilities, net increase (decrease)	249		30
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax benefit (expense)	1		2
Actuarial (gains) losses arising during the year	1		-4
Prior year service cost (credit) arising during the year	-6		-3
Amortization of prior year actuarial gains (losses)			1
Amortization of prior year prior service credit	2
Net amount recognized in accumulated other comprehensive (income) loss	-2		-4
Other Post-Retirement Benefit Plans [Member] | Duke Energy Carolinas [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	34		-51
Regulatory liabilities, net increase (decrease)	76
Other Post-Retirement Benefit Plans [Member] | Progress Energy [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	129		-634
Regulatory liabilities, net increase (decrease)	122
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) [Abstract]
Deferred income tax benefit (expense)	1
Actuarial (gains) losses arising during the year	-2
Net amount recognized in accumulated other comprehensive (income) loss	-1
Other Post-Retirement Benefit Plans [Member] | Duke Energy Progress [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	97		-388
Regulatory liabilities, net increase (decrease)	61
Other Post-Retirement Benefit Plans [Member] | Duke Energy Florida [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	-4		-166
Regulatory liabilities, net increase (decrease)	61
Other Post-Retirement Benefit Plans [Member] | Duke Energy Ohio [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory liabilities, net increase (decrease)	-2		3
Other Post-Retirement Benefit Plans [Member] | Duke Energy Indiana [Member]
Amounts Recognized in Regulatory Assets and Liabilities [Abstract]
Regulatory assets, net increase (decrease)	-7		-6
Regulatory liabilities, net increase (decrease)	$14		$9
[1]	Net of insignificant tax expense in 2014, $17 million tax expense in 2013 and $9 million tax expense in 2012. See Note 21 for additional information.

Employee_Benefit_Plans_Project

Employee Benefit Plans (Projected Benefit Obligations Reconciliation of Funded Status to Net Amount Recognized) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Qualified Pension Plans [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	$7,510	$8,030
Service cost	135	167	122
Interest cost on projected benefit obligation	344	320	307
Actuarial (gains) losses	618	-399
Plan amendments	-4	-41
Benefits paid	-496	-567
Obligation at measurement date	8,107	7,510	8,030
Accumulated benefit obligation at measurement date	7,966	7,361
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	8,142	7,754
Actual return on plan assets	852	705
Benefits paid	-496	-567
Employer contributions		250	304
Plan assets at measurement date	8,498	8,142	7,754
Funded status of plan	391	632
Qualified Pension Plans [Member] | Change in Assumptions for Pension Plans [Member]
Change in Projected Benefit Obligation [Rollforward]
Actuarial (gains) losses	180
Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	1,875	2,028
Service cost	41	49	35
Interest cost on projected benefit obligation	85	80	90
Actuarial (gains) losses	132	-73
Transfers of benefit obligation	37	-26
Plan amendments	-1	-13
Benefits paid	-116	-170
Obligation at measurement date	2,053	1,875	2,028
Accumulated benefit obligation at measurement date	2,052	1,875
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	2,162	2,151
Actual return on plan assets	217	207
Benefits paid	-116	-170
Transfer of plan assets	37	-26
Plan assets at measurement date	2,300	2,162	2,151
Funded status of plan	247	287
Qualified Pension Plans [Member] | Progress Energy [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	2,739	2,868
Service cost	40	60	63
Interest cost on projected benefit obligation	112	116	127
Actuarial (gains) losses	211	-118
Transfers of benefit obligation	-375	-7
Plan amendments		-19
Benefits paid	-170	-161
Obligation at measurement date	2,557	2,739	2,868
Accumulated benefit obligation at measurement date	2,519	2,698
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	2,944	2,647
Actual return on plan assets	300	215
Benefits paid	-170	-161
Transfer of plan assets	-352	-7
Employer contributions		250	346
Plan assets at measurement date	2,722	2,944	2,647
Funded status of plan	165	205
Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	1,172	1,264
Service cost	21	22	25
Interest cost on projected benefit obligation	54	50	58
Actuarial (gains) losses	98	-26
Transfers of benefit obligation	-61	-45
Plan amendments		-8
Benefits paid	-97	-85
Obligation at measurement date	1,187	1,172	1,264
Accumulated benefit obligation at measurement date	1,187	1,172
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	1,330	1,289
Actual return on plan assets	149	108
Benefits paid	-97	-85
Transfer of plan assets	-61	-45
Employer contributions		63	141
Plan assets at measurement date	1,321	1,330	1,289
Funded status of plan	134	158
Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	1,233	1,309
Service cost	20	30	30
Interest cost on projected benefit obligation	57	53	56
Actuarial (gains) losses	105	-75
Transfers of benefit obligation	-9	-17
Plan amendments		-7
Benefits paid	-71	-60
Obligation at measurement date	1,335	1,233	1,309
Accumulated benefit obligation at measurement date	1,297	1,192
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	1,299	1,150
Actual return on plan assets	144	93
Benefits paid	-71	-60
Transfer of plan assets	-9	-17
Employer contributions		133	128
Plan assets at measurement date	1,363	1,299	1,150
Funded status of plan	28	66
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	442	527
Service cost	4	6	6
Interest cost on projected benefit obligation	20	21	31
Actuarial (gains) losses	41	-71
Transfers of benefit obligation	-6	-2
Plan amendments	-1
Benefits paid	-31	-39
Obligation at measurement date	469	442	527
Accumulated benefit obligation at measurement date	459	429
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	448	446
Actual return on plan assets	45	43
Benefits paid	-31	-39
Transfer of plan assets	-6	-2
Plan assets at measurement date	456	448	446
Funded status of plan	-13	6
Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	632	684
Service cost	9	11	9
Interest cost on projected benefit obligation	29	28	30
Actuarial (gains) losses	41	-56
Transfers of benefit obligation		-2
Benefits paid	-38	-33
Obligation at measurement date	673	632	684
Accumulated benefit obligation at measurement date	645	608
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	654	627
Actual return on plan assets	65	62
Benefits paid	-38	-33
Transfer of plan assets		-2
Plan assets at measurement date	681	654	627
Funded status of plan	8	22
Non Qualified Pension Plans [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	304	335
Service cost	3	3	2
Interest cost on projected benefit obligation	14	13	12
Actuarial (gains) losses	43	-15
Settlements		-5
Plan amendments		-1
Benefits paid	-27	-26
Obligation at measurement date	337	304	335
Accumulated benefit obligation at measurement date	333	302
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-27	-26
Employer contributions	27	26
Non Qualified Pension Plans [Member] | Change in Assumptions for Pension Plans [Member]
Change in Projected Benefit Obligation [Rollforward]
Actuarial (gains) losses	21
Non Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	15	16
Interest cost on projected benefit obligation	1	1	1
Actuarial (gains) losses	2	1
Benefits paid	-2	-3
Obligation at measurement date	16	15	16
Accumulated benefit obligation at measurement date	15	15
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-2	-3
Employer contributions	2	3
Non Qualified Pension Plans [Member] | Progress Energy [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	140	176
Service cost	1	1	2
Interest cost on projected benefit obligation	5	7	8
Actuarial (gains) losses	11	-11
Transfers of benefit obligation	-32	-21
Benefits paid	-9	-12
Obligation at measurement date	116	140	176
Accumulated benefit obligation at measurement date	116	140
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-9	-12
Employer contributions	9	12
Non Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	34	38
Service cost	1	1	1
Interest cost on projected benefit obligation	1	1	1
Actuarial (gains) losses	2	-3
Benefits paid	-3	-3
Obligation at measurement date	35	34	38
Accumulated benefit obligation at measurement date	35	34
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-3	-3
Employer contributions	3	3
Non Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	39	45
Interest cost on projected benefit obligation	2	1	2
Actuarial (gains) losses	20	-3
Transfers of benefit obligation	4
Benefits paid	-4	-4
Obligation at measurement date	61	39	45
Accumulated benefit obligation at measurement date	61	39
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-4	-4
Employer contributions	4	4
Non Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	3	4
Actuarial (gains) losses	1	-1
Obligation at measurement date	4	3
Accumulated benefit obligation at measurement date	4	3
Non Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	5
Actuarial (gains) losses	1
Benefits paid	-1
Obligation at measurement date	5		5
Accumulated benefit obligation at measurement date	5	5
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-1
Employer contributions	1
Other Post-Retirement Benefit Plans [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	1,106	1,794
Service cost	10	24	16
Interest cost on projected benefit obligation	49	68	56
Plan participants' contributions	25	47
Actuarial (gains) losses	-87	-227
Plan amendments	-85	-476
Benefits paid	-103	-132
Accrued retiree drug subsidy	1	8
Obligation at measurement date	916	1,106	1,794
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	214	198
Actual return on plan assets	18	18
Benefits paid	-103	-132
Employer contributions	73	83
Plan participants' contributions	25	47
Plan assets at measurement date	227	214	198
Other Post-Retirement Benefit Plans [Member] | Change in Assumptions for Pension Plans [Member]
Change in Projected Benefit Obligation [Rollforward]
Actuarial (gains) losses	7
Other Post-Retirement Benefit Plans [Member] | Duke Energy Carolinas [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	265	316
Service cost	2	2	2
Interest cost on projected benefit obligation	12	13	15
Plan participants' contributions	10	15
Actuarial (gains) losses	-35	-32
Transfers of benefit obligation	1
Plan amendments	-4	-16
Benefits paid	-31	-36
Accrued retiree drug subsidy		3
Obligation at measurement date	220	265	316
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	143	134
Actual return on plan assets	12	13
Benefits paid	-31	-36
Transfer of plan assets	-1	-1
Employer contributions	12	18
Plan participants' contributions	10	15
Plan assets at measurement date	145	143	134
Other Post-Retirement Benefit Plans [Member] | Progress Energy [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	533	1,128
Service cost	4	18	17
Interest cost on projected benefit obligation	22	41	43
Plan participants' contributions	8	14
Actuarial (gains) losses	-19	-156
Transfers of benefit obligation	-48	-1
Plan amendments	-77	-455
Benefits paid	-44	-60
Accrued retiree drug subsidy		4
Obligation at measurement date	379	533	1,128
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-44	-60
Employer contributions	36	46
Plan participants' contributions	8	14
Other Post-Retirement Benefit Plans [Member] | Duke Energy Progress [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	233	612
Service cost	1	9	8
Interest cost on projected benefit obligation	11	22	23
Plan participants' contributions	4	6
Actuarial (gains) losses	-21	-73
Transfers of benefit obligation	-2	-8
Plan amendments		-311
Benefits paid	-19	-26
Accrued retiree drug subsidy		2
Obligation at measurement date	207	233	612
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-19	-26
Employer contributions	14	20
Plan participants' contributions	4	6
Plan assets at measurement date	-1
Other Post-Retirement Benefit Plans [Member] | Duke Energy Florida [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	253	413
Service cost	3	7	7
Interest cost on projected benefit obligation	12	16	18
Plan participants' contributions	4	7
Actuarial (gains) losses		-70
Plan amendments	-78	-91
Benefits paid	-24	-31
Accrued retiree drug subsidy		2
Obligation at measurement date	170	253	413
Change in Fair Value of Plan Assets [Rollforward]
Benefits paid	-24	-31
Employer contributions	20	24
Plan participants' contributions	4	7
Other Post-Retirement Benefit Plans [Member] | Duke Energy Ohio [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	42	48
Service cost		1	1
Interest cost on projected benefit obligation	2	2	3
Plan participants' contributions		3
Actuarial (gains) losses		-6
Transfers of benefit obligation	-1
Plan amendments	-1
Benefits paid	-3	-6
Obligation at measurement date	39	42	48
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	8	7
Actual return on plan assets		2
Benefits paid	-3	-6
Employer contributions	3	2
Plan participants' contributions		3
Plan assets at measurement date	8	8	7
Other Post-Retirement Benefit Plans [Member] | Duke Energy Indiana [Member]
Change in Projected Benefit Obligation [Rollforward]
Obligation at prior measurement date	118	136
Service cost	1	1	1
Interest cost on projected benefit obligation	5	5	6
Plan participants' contributions	2	3
Actuarial (gains) losses	-20	-12
Plan amendments		-3
Benefits paid	-10	-14
Accrued retiree drug subsidy		2
Obligation at measurement date	96	118	136
Change in Fair Value of Plan Assets [Rollforward]
Plan assets at prior measurement date	18	17
Actual return on plan assets	2	2
Benefits paid	-10	-14
Employer contributions	11	10
Plan participants' contributions	2	3
Plan assets at measurement date	$23	$18	$17

Employee_Benefit_Plans_Amounts1

Employee Benefit Plans (Amounts Recognized in Consolidated Balance Sheets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	$1,145	$1,322
Regulatory assets	12,157	10,086
Regulatory liabilities	6,397	6,265
Duke Energy Carolinas [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	111	161
Regulatory assets	2,864	1,822
Regulatory liabilities	2,744	2,641
Progress Energy [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	533	765
Regulatory assets	5,899	4,508
Regulatory liabilities	2,485	2,499
Duke Energy Progress [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	290	321
Regulatory assets	2,962	1,511
Regulatory liabilities	1,903	1,736
Duke Energy Florida [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	221	286
Regulatory assets	2,936	2,950
Regulatory liabilities	582	762
Duke Energy Ohio [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	48	58
Regulatory assets	561	528
Regulatory liabilities	251	289
Duke Energy Indiana [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	82	163
Regulatory assets	778	835
Regulatory liabilities	850	798
Qualified Pension Plans [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Prefunded pension	441	632
Noncurrent pension liability	50
Net amount recognized	391	632
Regulatory assets	1,711	1,599
Accumulated Other Comprehensive Income (Loss) [Abstract]
Deferred income tax asset	-51	-41
Prior year service cost (credit) arising during the year	-5	-5
Net actuarial loss (gain)	140	121
Net amount recognized in accumulated other comprehensive income (loss)	84	75
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	166
Unrecognized prior service (credit) cost	-15
Qualified Pension Plans [Member] | Brazilian Retirement Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Net amount recognized in accumulated other comprehensive income (loss)	22	16
Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Prefunded pension	247	287
Net amount recognized	247	287
Regulatory assets	407	377
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	39
Unrecognized prior service (credit) cost	-8
Qualified Pension Plans [Member] | Progress Energy [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Prefunded pension	165	230
Noncurrent pension liability		25
Net amount recognized	165	205
Regulatory assets	753	826
Accumulated Other Comprehensive Income (Loss) [Abstract]
Deferred income tax asset	-11	-9
Net actuarial loss (gain)	21	21
Net amount recognized in accumulated other comprehensive income (loss)	10	12
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	65
Unrecognized prior service (credit) cost	-3
Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Prefunded pension	134	158
Net amount recognized	134	158
Regulatory assets	346	363
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	34
Unrecognized prior service (credit) cost	-2
Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Prefunded pension	28	66
Net amount recognized	28	66
Regulatory assets	406	395
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	31
Unrecognized prior service (credit) cost	-1
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Prefunded pension		2
Noncurrent pension liability	13	-4
Net amount recognized	-13	6
Regulatory assets	65	48
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	6
Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Prefunded pension	8	75
Noncurrent pension liability		53
Net amount recognized	8	22
Regulatory assets	151	147
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	14
Non-Qualified Pension Plans [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	27	30
Noncurrent pension liability	310	274
Total accrued pension liability	337	304
Regulatory assets	89	45
Regulatory liabilities		7
Accumulated Other Comprehensive Income (Loss) [Abstract]
Deferred income tax asset	4
Prior year service cost (credit) arising during the year	-1	-1
Net actuarial loss (gain)	-8	1
Net amount recognized in accumulated other comprehensive income (loss)	-5
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	6
Unrecognized prior service (credit) cost	-1
Non-Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	2	2
Noncurrent pension liability	14	13
Total accrued pension liability	16	15
Regulatory assets	5	4
Regulatory liabilities		0
Non-Qualified Pension Plans [Member] | Progress Energy [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	8	11
Noncurrent pension liability	108	129
Total accrued pension liability	116	140
Regulatory assets	32	18
Regulatory liabilities		0
Accumulated Other Comprehensive Income (Loss) [Abstract]
Deferred income tax asset	2	-3
Net actuarial loss (gain)	-4	7
Net amount recognized in accumulated other comprehensive income (loss)	-2	4
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	2
Non-Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	3	2
Noncurrent pension liability	32	32
Total accrued pension liability	35	34
Regulatory assets	7	3
Regulatory liabilities		0
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	1
Non-Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	4	3
Noncurrent pension liability	57	36
Total accrued pension liability	61	39
Regulatory assets	25	6
Regulatory liabilities		0
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	2
Non-Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	0
Noncurrent pension liability	4	3
Total accrued pension liability	4	3
Regulatory assets	1
Regulatory liabilities		0
Non-Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	0
Noncurrent pension liability	5	5
Total accrued pension liability	5	5
Regulatory assets	2
Regulatory liabilities		0
Other Post-Retirement Benefit Plans [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	35	39
Noncurrent pension liability	654	853
Total accrued pension liability	689	892
Regulatory assets		-162
Regulatory liabilities	380	131
Accumulated Other Comprehensive Income (Loss) [Abstract]
Deferred income tax liability	5	4
Prior year service cost (credit) arising during the year	-9	-5
Net actuarial loss (gain)	-5	-6
Net amount recognized in accumulated other comprehensive income (loss)	-9	-7
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	16
Unrecognized prior service (credit) cost	-140
Other Post-Retirement Benefit Plans [Member] | Duke Energy Carolinas [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	75	122
Total accrued pension liability	75	122
Regulatory assets		-34
Regulatory liabilities	76
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	-1
Unrecognized prior service (credit) cost	-14
Other Post-Retirement Benefit Plans [Member] | Progress Energy [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	29	36
Noncurrent pension liability	350	497
Total accrued pension liability	379	533
Regulatory assets		-129
Regulatory liabilities	122
Accumulated Other Comprehensive Income (Loss) [Abstract]
Deferred income tax liability	1
Net actuarial loss (gain)	-2
Net amount recognized in accumulated other comprehensive income (loss)	-1
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	28
Unrecognized prior service (credit) cost	-103
Other Post-Retirement Benefit Plans [Member] | Duke Energy Progress [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	16	17
Noncurrent pension liability	192	216
Total accrued pension liability	208	233
Regulatory assets		-97
Regulatory liabilities	61
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	18
Unrecognized prior service (credit) cost	-68
Other Post-Retirement Benefit Plans [Member] | Duke Energy Florida [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	14	16
Noncurrent pension liability	156	237
Total accrued pension liability	170	253
Regulatory assets		4
Regulatory liabilities	61
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	10
Unrecognized prior service (credit) cost	-35
Other Post-Retirement Benefit Plans [Member] | Duke Energy Ohio [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Current pension liability	2	2
Noncurrent pension liability	29	32
Total accrued pension liability	31	34
Regulatory liabilities	19	21
Amounts to be recognized in net periodic pension expense in the next year [Abstract]
Unrecognized net actuarial loss	-2
Other Post-Retirement Benefit Plans [Member] | Duke Energy Indiana [Member]
Amounts Recognized in Consolidated Balance Sheets [Abstract]
Noncurrent pension liability	73	100
Total accrued pension liability	73	100
Regulatory assets	64	71
Regulatory liabilities	$91	$77

Employee_Benefit_Plans_Informa

Employee Benefit Plans (Information For Plans with Accumulated Benefit Obligation in Excess of Plan Assets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Qualified Pension Plans [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	$702
Accumulated benefit obligation	672
Fair value of plan assets	652
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	315
Accumulated benefit obligation	306
Fair value of plan assets	302
Non-Qualified Pension Plans [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	337	304
Accumulated benefit obligation	333	302
Non-Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	16	15
Accumulated benefit obligation	15	15
Non-Qualified Pension Plans [Member] | Progress Energy [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	116	140
Accumulated benefit obligation	116	140
Non-Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	35	34
Accumulated benefit obligation	35	34
Non-Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	61	39
Accumulated benefit obligation	61	39
Non-Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	4	3
Accumulated benefit obligation	4	3
Non-Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Information For Plans With Accumulated Benefit Obligation In Excess Of Plan Assets [Abstract]
Projected benefit obligation	5	5
Accumulated benefit obligation	$5	$5

Employee_Benefit_Plans_Assumpt

Employee Benefit Plans (Assumptions Used For Pension Benefits Accounting) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Qualified Pension Plans [Member]
Benefit Obligations [Abstract]
Discount rate	4.10%	4.70%	4.10%
Net Periodic Benefit Cost [Abstract]
Discount rate	4.70%	4.10%
Expected long-term rate of return on plan assets	6.75%	7.75%
Qualified Pension Plans [Member] | Minimum [Member]
Benefit Obligations [Abstract]
Salary increase	4.00%	4.00%	4.00%
Net Periodic Benefit Cost [Abstract]
Discount rate			4.60%
Salary increase	4.00%	4.00%	4.00%
Expected long-term rate of return on plan assets			8.00%
Qualified Pension Plans [Member] | Maximum [Member]
Benefit Obligations [Abstract]
Salary increase	4.40%	4.40%	4.30%
Net Periodic Benefit Cost [Abstract]
Discount rate			5.10%
Salary increase	4.40%	4.30%	4.40%
Expected long-term rate of return on plan assets			8.25%
Non-Qualified Pension Plans [Member]
Benefit Obligations [Abstract]
Discount rate	4.10%	4.70%	4.10%
Salary increase	4.40%	4.40%	4.30%
Net Periodic Benefit Cost [Abstract]
Discount rate	4.70%	4.10%
Salary increase	4.40%	4.30%	4.40%
Non-Qualified Pension Plans [Member] | Minimum [Member]
Net Periodic Benefit Cost [Abstract]
Discount rate			4.60%
Non-Qualified Pension Plans [Member] | Maximum [Member]
Net Periodic Benefit Cost [Abstract]
Discount rate			5.10%
Other Post-Retirement Benefit Plans [Member]
Benefit Obligations [Abstract]
Discount rate	4.10%	4.70%	4.10%
Net Periodic Benefit Cost [Abstract]
Discount rate	4.70%	4.10%
Expected long-term rate of return on plan assets	6.75%	7.75%
Assumed tax rate	35.00%	35.00%	35.00%
Other Post-Retirement Benefit Plans [Member] | Minimum [Member]
Net Periodic Benefit Cost [Abstract]
Discount rate			4.60%
Expected long-term rate of return on plan assets			5.00%
Other Post-Retirement Benefit Plans [Member] | Maximum [Member]
Net Periodic Benefit Cost [Abstract]
Discount rate			5.10%
Expected long-term rate of return on plan assets			8.00%

Employee_Benefit_Plans_Assumed

Employee Benefit Plans (Assumed Health Care Cost Trend Rates) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate assumed for next year	6.75%	8.50%
Rate to which the cost trend is assumed to decline (the ultimate trend rate)	4.75%	5.00%
Year that the rate reaches the ultimate trend rate	2023	2021

Employee_Benefit_Plans_Sensiti

Employee Benefit Plans (Sensitivity to Changes in Assumed Health Care Cost Trend Rates) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	$2
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	36
Effect on total service and interest costs - 1 Percentage Point Decrease	-2
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	-31
Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	1
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	9
Effect on total service and interest costs - 1 Percentage Point Decrease	-1
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	-8
Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	1
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	15
Effect on total service and interest costs - 1 Percentage Point Decrease	-1
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	-13
Duke Energy Progress [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	8
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	-7
Duke Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on total service and interest costs - 1 Percentage Point Increase	1
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	7
Effect on total service and interest costs - 1 Percentage Point Decrease	-1
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	-6
Duke Energy Ohio [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	2
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	-1
Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect on post-retirement benefit obligation - 1 Percentage Point Increase	4
Effect on post-retirement benefit obligation - 1 Percentage Point Decrease	($3)

Employee_Benefit_Plans_Expecte

Employee Benefit Plans (Expected Benefit Payments) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Qualified Pension Plans [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	$584
2016	604
2017	616
2018	625
2019	626
2020-2024	3,107
Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	175
2016	184
2017	195
2018	200
2019	194
2020-2024	924
Qualified Pension Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	150
2016	158
2017	161
2018	165
2019	168
2020-2024	868
Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	80
2016	85
2017	86
2018	87
2019	88
2020-2024	437
Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	67
2016	70
2017	73
2018	76
2019	78
2020-2024	420
Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	34
2016	35
2017	34
2018	34
2019	34
2020-2024	168
Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	45
2016	46
2017	45
2018	46
2019	46
2020-2024	229
Non-Qualified Pension Plans [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	28
2016	27
2017	27
2018	24
2019	24
2020-2024	116
Non-Qualified Pension Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	2
2016	2
2017	2
2018	2
2019	2
2020-2024	6
Non-Qualified Pension Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	8
2016	8
2017	8
2018	8
2019	8
2020-2024	38
Non-Qualified Pension Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	3
2016	3
2017	3
2018	3
2019	3
2020-2024	13
Non-Qualified Pension Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	4
2016	4
2017	4
2018	4
2019	4
2020-2024	19
Non-Qualified Pension Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2020-2024	2
Non-Qualified Pension Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2020-2024	2
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	77
2016	77
2017	76
2018	74
2019	73
2020-2024	332
Other Post-Retirement Benefit Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	17
2016	18
2017	18
2018	19
2019	19
2020-2024	84
Other Post-Retirement Benefit Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	30
2016	30
2017	29
2018	29
2019	29
2020-2024	132
Other Post-Retirement Benefit Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	16
2016	16
2017	15
2018	15
2019	15
2020-2024	70
Other Post-Retirement Benefit Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	14
2016	14
2017	14
2018	14
2019	13
2020-2024	61
Other Post-Retirement Benefit Plans [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	4
2016	4
2017	3
2018	3
2019	3
2020-2024	15
Other Post-Retirement Benefit Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	10
2016	10
2017	9
2018	9
2019	8
2020-2024	$35

Employee_Benefit_Plans_Target_

Employee Benefit Plans (Target and Actual Asset Allocations) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	100.00%	100.00%
Target allocation	100.00%
Master Trust [Member] | US Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	10.00%	10.00%
Target allocation	10.00%
Master Trust [Member] | Non US Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	8.00%	8.00%
Target allocation	8.00%
Master Trust [Member] | Global Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	10.00%	10.00%
Target allocation	10.00%
Master Trust [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	63.00%	63.00%
Target allocation	63.00%
Master Trust [Member] | Global Private Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	3.00%	3.00%
Target allocation	3.00%
Master Trust [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	3.00%	3.00%
Target allocation	2.00%
Master Trust [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	1.00%	1.00%
Target allocation	2.00%
Master Trust [Member] | Other Global Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	2.00%	2.00%
Target allocation	2.00%
VEBA I [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	100.00%	100.00%
Target allocation	100.00%
VEBA I [Member] | US Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	29.00%	29.00%
Target allocation	30.00%
VEBA I [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	43.00%	42.00%
Target allocation	25.00%
VEBA I [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation	28.00%	29.00%
Target allocation	45.00%

Employee_Benefit_Plans_Fair_Va

Employee Benefit Plans (Fair Value Measurements of Plan Assets - Master Retirement Trust) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	$8,618	$8,261
Master Trust [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1,816	2,120
Master Trust [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	6,366	5,595
Master Trust [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	436	546
Master Trust [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	2,346	2,877
Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1,625	1,801
Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	721	1,022
Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets		54
Master Trust [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	4,349	2,604
Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	4,348	2,601
Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1	3
Master Trust [Member] | Short Term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	333	1,158
Master Trust [Member] | Short Term Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	171	254
Master Trust [Member] | Short Term Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	162	904
Master Trust [Member] | Partnership Interest [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	298	307
Master Trust [Member] | Partnership Interest [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	298	307
Master Trust [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	146	164
Master Trust [Member] | Hedge Funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	146	111
Master Trust [Member] | Hedge Funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets		53
Master Trust [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	104	95
Master Trust [Member] | Real Estate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	104	95
Master Trust [Member] | US Treasury and Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	917	927
Master Trust [Member] | US Treasury and Government [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	916	927
Master Trust [Member] | US Treasury and Government [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1
Master Trust [Member] | Guaranteed Investment Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	32	33
Master Trust [Member] | Guaranteed Investment Contracts [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	32	33
Master Trust [Member] | Government Bonds - Foreign [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	44	19
Master Trust [Member] | Government Bonds - Foreign [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	44	18
Master Trust [Member] | Government Bonds - Foreign [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets		1
Master Trust [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	30	58
Master Trust [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	30	58
Master Trust [Member] | Asset Backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	9	7
Master Trust [Member] | Asset Backed Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	9	7
Master Trust [Member] | Miscellaneous Investments And Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	10	12
Master Trust [Member] | Miscellaneous Investments And Other [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	-10	7
Master Trust [Member] | Miscellaneous Investments And Other [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	20	5
VEBA I [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	48	51
VEBA I [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	48	51
VEBA I [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	14	15
VEBA I [Member] | Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	14	15
VEBA I [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	21	21
VEBA I [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	21	21
VEBA I [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	13	15
VEBA I [Member] | Debt Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	$13	$15
Duke Energy Carolinas [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	28.00%	28.00%
Progress Energy [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	31.00%	35.00%
Duke Energy Progress [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	15.00%	16.00%
Duke Energy Florida [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	16.00%	16.00%
Duke Energy Ohio [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	5.00%	5.00%
Duke Energy Indiana [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	8.00%	8.00%

Employee_Benefit_Plans_Reconci

Employee Benefit Plans (Reconciliation of Assets Measured at Fair Value on a Recurring Basis) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$111	$13	$85
Purchases	84	30	36
Sales	-58	-6	-2
Total gains (losses) and other, net	-7	-42	8
Ending balance	155	111	13
Master Trust [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	546	352
Combination of trust assets		288
Purchases	17	25
Sales	-164	-152
Total gains (losses) and other, net	37	33
Ending balance	$436	$546

Employee_Benefit_Plans_Employe

Employee Benefit Plans (Employee Savings Plans)(Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Savings Plans [Abstract]
Matching contribution percentage	100.00%
Eligible pay percentage	6.00%
Additional contribution percentage for employees not participating in defined pension plans	4.00%
Pretax employer matching contributions	$143	$134	$107
Duke Energy Carolinas [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	47	45	37
Progress Energy [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	43	45	45
Duke Energy Progress [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	30	25	24
Duke Energy Florida [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	14	14	15
Duke Energy Ohio [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	3	3	4
Duke Energy Indiana [Member]
Employee Savings Plans [Abstract]
Pretax employer matching contributions	$7	$7	$6

Income_Taxes_Components_of_Inc

Income Taxes (Components of Income Tax Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes		($141)	($108)
Current state taxes	56	-40	29
Current foreign taxes	144	151	133
Total current income taxes	200	-30	54
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	1,517	1,092	491
Deferred state taxes	35	144	71
Deferred foreign taxes	-67	14	20
Total deferred income taxes	1,485	1,250	582
Investment tax credit amortization	-16	-15	-13
Income tax expense (benefit) from continuing operations	1,669	1,205	623
Tax expense (benefit) from discontinued operations	-295	29	107
Total income tax expense included in Consolidated Statements of Operations	1,374	1,234	730
Net operating loss utilization	1,544
Net operating loss carry forward		808	1,062
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Domestic	3,600	3,183	1,600
Foreign	534	612	634
Total income (loss) from continuing operations before income taxes	4,134	3,795	2,234
Duke Energy Carolinas [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	161	49	-1
Current state taxes	51	11	-25
Total current income taxes	212	60	-26
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	407	464	408
Deferred state taxes	-25	75	77
Total deferred income taxes	382	539	485
Investment tax credit amortization	-6	-5	-6
Income tax expense (benefit) from continuing operations	588	594	453
Total income tax expense included in Consolidated Statements of Operations	588	594	453
Net operating loss utilization	345
Net operating loss carry forward	0		245
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Total income (loss) from continuing operations before income taxes	1,660	1,570	1,318
Progress Energy [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	-466	-221	-88
Current state taxes	-8	-37	2
Total current income taxes	-474	-258	-86
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	938	555	226
Deferred state taxes	84	84	40
Total deferred income taxes	1,022	639	266
Investment tax credit amortization	-8	-8	-8
Income tax expense (benefit) from continuing operations	540	373	172
Tax expense (benefit) from discontinued operations	-4	-26	29
Total income tax expense included in Consolidated Statements of Operations	536	347	201
Net operating loss utilization	530
Net operating loss carry forward		458	357
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Total income (loss) from continuing operations before income taxes	1,420	1,032	527
Duke Energy Progress [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	-184	-70	-48
Current state taxes	14	-10	-6
Total current income taxes	-170	-80	-54
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	436	316	162
Deferred state taxes	25	59	9
Total deferred income taxes	461	375	171
Investment tax credit amortization	-6	-7	-7
Income tax expense (benefit) from continuing operations	285	288	110
Total income tax expense included in Consolidated Statements of Operations	285	288	110
Net operating loss utilization	291
Net operating loss carry forward		64	257
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Total income (loss) from continuing operations before income taxes	752	788	382
Duke Energy Florida [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	-53	-143	6
Current state taxes	1	-13
Total current income taxes	-52	-156	6
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	350	326	121
Deferred state taxes	52	44	21
Total deferred income taxes	402	370	142
Investment tax credit amortization	-1	-1	-1
Income tax expense (benefit) from continuing operations	349	213	147
Total income tax expense included in Consolidated Statements of Operations	349	213	147
Net operating loss utilization	64
Net operating loss carry forward		301	25
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Total income (loss) from continuing operations before income taxes	897	538	413
Duke Energy Ohio [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	-73	-24	-8
Current state taxes	3	-4	5
Total current income taxes	-70	-28	-3
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	113	65	40
Deferred state taxes	1	6	-2
Total deferred income taxes	114	71	38
Investment tax credit amortization	-1		-2
Income tax expense (benefit) from continuing operations	43	43	33
Tax expense (benefit) from discontinued operations	-300	32	65
Total income tax expense included in Consolidated Statements of Operations	-257	75	98
Net operating loss utilization	56
Net operating loss carry forward			34
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Total income (loss) from continuing operations before income taxes	111	110	78
Duke Energy Indiana [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	-112	-88	-27
Current state taxes	1	7	27
Total current income taxes	-111	-81
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	294	276	-47
Deferred state taxes	15	29	-25
Total deferred income taxes	309	305	-72
Investment tax credit amortization	-1	-1	-1
Income tax expense (benefit) from continuing operations	197	223	-73
Total income tax expense included in Consolidated Statements of Operations	197	223	-73
Net operating loss utilization	141
Net operating loss carry forward		179	205
Duke Energy Income from Continuing Operations Before Income Taxes [Abstract]
Total income (loss) from continuing operations before income taxes	$556	$581	($123)

Income_Taxes_Effective_Tax_Rat

Income Taxes (Effective Tax Rates) (Details) (USD $)	12 Months Ended			96 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2022
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	$1,447,000,000	$1,328,000,000	$782,000,000
State income tax, net of federal income tax effect	59,000,000	66,000,000	65,000,000
Tax differential on foreign earnings	-110,000,000	-49,000,000	-69,000,000
AFUDC equity income	-47,000,000	-55,000,000	-101,000,000
Renewable energy production tax credits	-67,000,000	-62,000,000	-25,000,000
International Tax Dividend	373,000,000
Other items, net	14,000,000	-23,000,000	-29,000,000
Income tax expense (benefit) from continuing operations	1,669,000,000	1,205,000,000	623,000,000
Effective tax rate	40.40%	31.80%	27.90%
State [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Net reduction in deferred tax liability		145,000,000
State [Member] | Current [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		6.90%
State [Member] | January 2014 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		6.00%
State [Member] | January 2015 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		5.00%
Foreign Jurisdictions [Member] | Merger of Subsidiaries [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense (benefit) from continuing operations	-57,000,000
Duke Energy Carolinas [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	581,000,000	549,000,000	461,000,000
State income tax, net of federal income tax effect	17,000,000	56,000,000	34,000,000
AFUDC equity income	-32,000,000	-32,000,000	-54,000,000
Other items, net	22,000,000	21,000,000	12,000,000
Income tax expense (benefit) from continuing operations	588,000,000	594,000,000	453,000,000
Effective tax rate	35.40%	37.80%	34.30%
Duke Energy Carolinas [Member] | State [Member] | Current [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		6.90%
Duke Energy Carolinas [Member] | State [Member] | January 2014 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		6.00%
Duke Energy Carolinas [Member] | State [Member] | January 2015 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		5.00%
Progress Energy [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	497,000,000	361,000,000	185,000,000
State income tax, net of federal income tax effect	49,000,000	31,000,000	33,000,000
AFUDC equity income	-9,000,000	-18,000,000	-37,000,000
Other items, net	3,000,000	-1,000,000	-9,000,000
Income tax expense (benefit) from continuing operations	540,000,000	373,000,000	172,000,000
Effective tax rate	38.00%	36.20%	32.70%
Duke Energy Progress [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	263,000,000	276,000,000	134,000,000
State income tax, net of federal income tax effect	25,000,000	31,000,000	1,000,000
AFUDC equity income	-9,000,000	-15,000,000	-24,000,000
Other items, net	6,000,000	-4,000,000	-1,000,000
Income tax expense (benefit) from continuing operations	285,000,000	288,000,000	110,000,000
Effective tax rate	37.90%	36.50%	28.70%
Duke Energy Progress [Member] | State [Member] | Current [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		6.90%
Duke Energy Progress [Member] | State [Member] | January 2014 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		6.00%
Duke Energy Progress [Member] | State [Member] | January 2015 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate		5.00%
Duke Energy Florida [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	314,000,000	188,000,000	145,000,000
State income tax, net of federal income tax effect	34,000,000	20,000,000	14,000,000
AFUDC equity income		-3,000,000	-13,000,000
Other items, net	1,000,000	8,000,000	1,000,000
Income tax expense (benefit) from continuing operations	349,000,000	213,000,000	147,000,000
Effective tax rate	38.90%	39.60%	35.70%
Duke Energy Ohio [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	39,000,000	39,000,000	27,000,000
State income tax, net of federal income tax effect	3,000,000	2,000,000	2,000,000
AFUDC equity income	-1,000,000		-2,000,000
Other items, net	2,000,000	2,000,000	6,000,000
Income tax expense (benefit) from continuing operations	43,000,000	43,000,000	33,000,000
Effective tax rate	38.90%	39.10%	42.90%
Duke Energy Indiana [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	195,000,000	203,000,000	-43,000,000
State income tax, net of federal income tax effect	10,000,000	23,000,000	1,000,000
AFUDC equity income	-5,000,000	-5,000,000	-26,000,000
Other items, net	-3,000,000	2,000,000	-5,000,000
Income tax expense (benefit) from continuing operations	197,000,000	223,000,000	-73,000,000
Effective tax rate	35.50%	38.40%	59.50%
Scenario, Forecast [Member] | International Energy [Member]
Income Tax Disclosure [Line Items]
Foreign Earnings Repatriated				$2,700,000,000

Income_Taxes_Deferred_Income_T

Income Taxes (Deferred Income Taxes) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	188	$245
Capital lease obligations	63	59
Pension, postretirement and other employee benefits	546	649
Progress Energy merger purchase accounting adjustments	1,124	1,184
Tax credits and NOL carryforwards	3,540	4,307
Other		265
Valuation allowance	-184	-192
Total deferred income tax assets	5,277	6,517
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	-1,625	-1,396
Accelerated depreciation rates	-11,715	-12,615
Regulatory assets and deferred debits	-3,694	-3,185
Other	-44
Total deferred income tax liabilities	-17,078	-17,196
Net deferred income tax liabilities	-11,801	-10,679
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	3,540	4,307
Valuation allowance	-184	-192
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Current Assets: Other	1,593	1,373
Investments and Other Assets: Other	29	45
Deferred Credits and Other Liabilities: Other	-13,423	-12,097
Net deferred income tax liabilities	-11,801	-10,679
Investment Tax Credits [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	581
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	581
Investment Tax Credits [Member] | Minimum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-29
Investment Tax Credits [Member] | Maximum [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-34
Alternative Minimum Tax Credit [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	1,093
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	1,093
NOL Carryforwards [Member] | Federal [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	749
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	749
NOL Carryforwards [Member] | State [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	162
Valuation allowance	-79
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	162
Valuation allowance	-79
NOL Carryforwards [Member] | Foreign Jurisdictions [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	117
Valuation allowance	-105
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	117
Valuation allowance	-105
NOL Carryforwards [Member] | Minimum [Member] | Federal [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-30
NOL Carryforwards [Member] | Minimum [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-15
NOL Carryforwards [Member] | Minimum [Member] | Foreign Jurisdictions [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-15
NOL Carryforwards [Member] | Maximum [Member] | Federal [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-33
NOL Carryforwards [Member] | Maximum [Member] | State [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-34
NOL Carryforwards [Member] | Maximum [Member] | Foreign Jurisdictions [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-33
Foreign Tax Credit [Member]
Deferred Tax Assets, Gross [Abstract]
Tax credits and NOL carryforwards	838
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	838
Foreign Tax Credit [Member] | Minimum [Member] | Foreign Jurisdictions [Member]
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Expiration year	31-Dec-24
Duke Energy Carolinas [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	53	56
Capital lease obligations	10	11
Pension, postretirement and other employee benefits	4	18
Tax credits and NOL carryforwards	157	488
Other	12	15
Total deferred income tax assets	236	588
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	-1,051	-999
Accelerated depreciation rates	-4,046	-4,400
Regulatory assets and deferred debits	-953	-609
Total deferred income tax liabilities	-6,050	-6,008
Net deferred income tax liabilities	-5,814	-5,420
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	157	488
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Current Assets: Other	3	286
Current Liabilities: Other	-5
Deferred Credits and Other Liabilities: Other	-5,812	-5,706
Net deferred income tax liabilities	-5,814	-5,420
Progress Energy [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	108	136
Pension, postretirement and other employee benefits	188	341
Tax credits and NOL carryforwards	980	1,965
Other		116
Valuation allowance	-13	-40
Total deferred income tax assets	1,263	2,518
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	-427	-209
Accelerated depreciation rates	-3,284	-3,663
Regulatory assets and deferred debits	-1,602	-1,389
Other	-151
Total deferred income tax liabilities	-5,464	-5,261
Net deferred income tax liabilities	-4,201	-2,743
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	980	1,965
Valuation allowance	-13	-40
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Current Assets: Other	558	540
Deferred Credits and Other Liabilities: Other	-4,759	-3,283
Net deferred income tax liabilities	-4,201	-2,743
Duke Energy Progress [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	28	9
Pension, postretirement and other employee benefits	96	119
Tax credits and NOL carryforwards	91	396
Other	55	39
Valuation allowance	-1	-1
Total deferred income tax assets	269	562
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	-232	-160
Accelerated depreciation rates	-2,030	-2,528
Regulatory assets and deferred debits	-809	-202
Total deferred income tax liabilities	-3,071	-2,890
Net deferred income tax liabilities	-2,802	-2,328
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	91	396
Valuation allowance	-1	-1
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Current Assets: Other	106	229
Deferred Credits and Other Liabilities: Other	-2,908	-2,557
Net deferred income tax liabilities	-2,802	-2,328
Duke Energy Florida [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	78	96
Pension, postretirement and other employee benefits	93	145
Tax credits and NOL carryforwards	252	365
Other		43
Total deferred income tax assets	423	649
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	-245	-49
Accelerated depreciation rates	-1,252	-1,160
Regulatory assets and deferred debits	-792	-1,159
Other	-246
Total deferred income tax liabilities	-2,535	-2,368
Net deferred income tax liabilities	-2,112	-1,719
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	252	365
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Current Assets: Other	340	110
Deferred Credits and Other Liabilities: Other	-2,452	-1,829
Net deferred income tax liabilities	-2,112	-1,719
Duke Energy Ohio [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	-8	-13
Pension, postretirement and other employee benefits	17	23
Tax credits and NOL carryforwards	38	165
Investments and other assets	14
Other	35	20
Total deferred income tax assets	96	195
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets		-17
Accelerated depreciation rates	-1,660	-1,937
Regulatory assets and deferred debits	-141	-168
Total deferred income tax liabilities	-1,801	-2,122
Net deferred income tax liabilities	-1,705	-1,927
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	38	165
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Current Assets: Other	60	85
Deferred Credits and Other Liabilities: Other	-1,765	-2,012
Net deferred income tax liabilities	-1,705	-1,927
Duke Energy Indiana [Member]
Deferred Tax Assets, Gross [Abstract]
Deferred credits and other liabilities	12	9
Capital lease obligations	2	-2
Pension, postretirement and other employee benefits	43	54
Tax credits and NOL carryforwards	260	521
Other	11	14
Total deferred income tax assets	328	596
Deferred Tax Liabilities, Gross [Abstract]
Investments and other assets	-4	-7
Accelerated depreciation rates	-1,603	-1,591
Regulatory assets and deferred debits	-106	-117
Total deferred income tax liabilities	-1,713	-1,715
Net deferred income tax liabilities	-1,385	-1,119
Components and Expiration Dates of Tax Credits and NOL Carryforwards [Abstract]
Tax credits and NOL carryforwards	260	521
Classification of Deferred Tax Assets (Liabiliities) in the Consolidated Balance Sheets [Abstract]
Current Assets: Other	206	52
Deferred Credits and Other Liabilities: Other	-1,591	-1,171
Net deferred income tax liabilities	-1,385	($1,119)

Income_Taxes_Other_Disclosures

Income Taxes (Other Disclosures) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	$230	$540	$385
Acquisitions			128
Gross increases-tax positions in prior periods			29
Gross decreases-tax positions in prior periods	-2	-231	-4
Gross increases-current period tax positions			28
Gross decreases - current period tax positions			-9
Decreases due to settlements	-15	-66	-13
Reduction due to lapse of statute of limitations		-13	-4
Total changes	-17	-310	155
Unrecognized Tax Benefits - December 31	213	230	540
Amount that if recognized, would affect the effective tax rate or regulatory liability	121
Amount that if recognized, would be recorded as a component of discontinued operations	8
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	28
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	6	2	10
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	13	27	7
Duke Energy Carolinas [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	171	271	260
Gross increases-tax positions in prior periods			12
Gross decreases-tax positions in prior periods		-100
Gross increases-current period tax positions			15
Gross decreases - current period tax positions			-5
Decreases due to settlements	-11		-11
Total changes	-11	-100	11
Unrecognized Tax Benefits - December 31	160	171	271
Amount that if recognized, would affect the effective tax rate or regulatory liability	112
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes		2	9
Net interest expense recognized related to income taxes	1
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest receivable related to income taxes			7
Interest payable related to income taxes	13	8
Progress Energy [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	32	131	173
Gross increases-tax positions in prior periods	1		23
Gross decreases-tax positions in prior periods		-86	-72
Gross increases-current period tax positions			8
Gross decreases - current period tax positions			-1
Decreases due to settlements	-1
Reduction due to lapse of statute of limitations		-13
Total changes		-99	-42
Unrecognized Tax Benefits - December 31	32	32	131
Amount that if recognized, would affect the effective tax rate or regulatory liability	3
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	28
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	3	6
Net interest expense recognized related to income taxes			2
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	5	10	17
Duke Energy Progress [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	22	67	73
Gross increases-tax positions in prior periods	1		10
Gross decreases-tax positions in prior periods		-45	-19
Gross increases-current period tax positions			4
Gross decreases - current period tax positions			-1
Total changes	1	-45	-6
Unrecognized Tax Benefits - December 31	23	22	67
Amount that if recognized, would affect the effective tax rate or regulatory liability	2
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	17
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes		7
Net interest expense recognized related to income taxes	1
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	3	2	8
Duke Energy Florida [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	8	44	80
Gross increases-tax positions in prior periods			12
Gross decreases-tax positions in prior periods		-37	-52
Gross increases-current period tax positions			4
Reduction due to lapse of statute of limitations		1
Total changes		-36	-36
Unrecognized Tax Benefits - December 31	8	8	44
Amount that if recognized, would affect the effective tax rate or regulatory liability	2
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	7
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	1
Net interest expense recognized related to income taxes			2
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	5	7	9
Duke Energy Ohio [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1		36	32
Gross increases-tax positions in prior periods			2
Gross decreases-tax positions in prior periods		-36
Gross increases-current period tax positions			4
Gross decreases - current period tax positions			-2
Total changes		-36	4
Unrecognized Tax Benefits - December 31			36
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	4	4
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes			3
Duke Energy Indiana [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	1	32	24
Gross increases-tax positions in prior periods			6
Gross decreases-tax positions in prior periods		-31
Gross increases-current period tax positions			4
Gross decreases - current period tax positions			-2
Total changes		-31	8
Unrecognized Tax Benefits - December 31	1	1	32
Amount that if recognized, would affect the effective tax rate or regulatory liability	2
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	4	1	2
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest receivable related to income taxes	2
Interest payable related to income taxes			$1

Other_Income_and_Expenses_Net_1

Other Income and Expenses, Net Other Income and Expenses, Net (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	$57	$26	$50
Foreign exchange gains (losses)	3	-18	4
Equity component of AFUDC	135	157	300
Deferred returns	89	39	24
Other income (expense)	67	58	19
Other income and expenses, net	351	262	397
Duke Energy Carolinas [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	4	1	11
Equity component of AFUDC	91	91	154
Deferred returns	71	32	24
Other income (expense)	6	-4	-4
Other income and expenses, net	172	120	185
Progress Energy [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	3	7	2
Equity component of AFUDC	26	50	106
Deferred returns	17	7
Other income (expense)	31	30	22
Other income and expenses, net	77	94	130
Duke Energy Progress [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income		1	1
Equity component of AFUDC	25	42	69
Deferred returns	17	7
Other income (expense)	9	7	9
Other income and expenses, net	51	57	79
Duke Energy Florida [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	2	3	1
Equity component of AFUDC		8	37
Other income (expense)	18	19	1
Other income and expenses, net	20	30	39
Duke Energy Ohio [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	8	5
Equity component of AFUDC	4	1	6
Other income (expense)	-2	-4	2
Other income and expenses, net	10	2	8
Duke Energy Indiana [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	6	6	7
Equity component of AFUDC	14	15	84
Other income (expense)	2	-3	-1
Other income and expenses, net	$22	$18	$90

Quarterly_Financial_Data_Unaud2

Quarterly Financial Data (Unaudited) (Schedule of Quarterly Financial Information) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	$5,559	$6,395	$5,708	$6,263	$5,610	$6,217	$5,393	$5,536	$23,925	$22,756	$17,912
Operating income (loss)	988	1,619	1,289	1,362	1,193	1,660	742	1,259	5,258	4,854	2,911
Income (loss) from continuing operations	99	891	725	750	689	946	292	663	2,465	2,590	1,611
Income (Loss) From Discontinued Operations, net of tax	1	378	-112	-843	3	62	50	-29	-576	86	171
Net income (loss)	100	1,269	613	-93	692	1,008	342	634	1,889	2,676	1,782
Net income (loss) attributable to Parent	97	1,274	609	-97	688	1,004	339	634	1,883	2,665	1,768
Income (loss) from continuing operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$0.14	$1.25	$1.02	$1.05	$0.96	$1.33	$0.40	$0.93	$3.46	$3.64	$2.77
Diluted	$0.14	$1.25	$1.02	$1.05	$0.96	$1.33	$0.40	$0.93	$3.46	$3.63	$2.77
Income (loss) from discontinued operations attributable To Duke Energy Corporation common shareholders [Abstract]
Basic		$0.55	($0.16)	($1.19)	$0.01	$0.09	$0.08	($0.04)	($0.80)	$0.13	$0.30
Diluted		$0.55	($0.16)	($1.19)	$0.01	$0.09	$0.08	($0.04)	($0.80)	$0.13	$0.30
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic	$0.14	$1.80	$0.86	($0.14)	$0.97	$1.42	$0.48	$0.89	$2.66	$3.77	$3.07
Diluted	$0.14	$1.80	$0.86	($0.14)	$0.97	$1.42	$0.48	$0.89	$2.66	$3.76	$3.07
Duke Energy Carolinas [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,658	1,938	1,755	2,000	1,715	1,919	1,591	1,729	7,351	6,954	6,665
Operating income (loss)	318	630	438	509	420	604	351	434	1,895	1,809	1,517
Net income (loss)	139	377	270	286	209	342	181	244	1,072	976
Net income (loss) attributable to Parent									1,072	976	865
Progress Energy [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	2,341	2,863	2,421	2,541	2,300	2,766	2,281	2,186	10,166	9,533	9,405
Operating income (loss)	388	665	488	477	403	671	114	430	2,018	1,618	1,137
Income (loss) from continuing operations	139	330	207	204	190	328	-13	154	880	659	355
Income (Loss) From Discontinued Operations, net of tax									-6	16	52
Net income (loss)	139	330	202	203	196	342	-17	154	874	675	407
Net income (loss) attributable to Parent	136	329	202	202	195	341	-17	153	869	672	400
Duke Energy Progress [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,196	1,367	1,191	1,422	1,211	1,430	1,135	1,216	5,176	4,992	4,706
Operating income (loss)	180	285	212	258	251	303	166	212	935	932	510
Net income (loss)	76	157	101	133	138	175	77	110	467	500	272
Duke Energy Florida [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	1,143	1,491	1,225	1,116	1,085	1,332	1,142	968	4,975	4,527	4,689
Operating income (loss)	205	378	276	219	151	369	-53	221	1,078	688	629
Net income (loss)	93	205	142	108	75	197	-57	110	548	325	266
Duke Energy Ohio [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	480	446	412	575	456	438	408	503	1,913	1,805	1,820
Operating income (loss)	74	58	62	-7	49	50	27	56	187	182	159
Income (loss) from continuing operations									68	67	45
Income (Loss) From Discontinued Operations, net of tax	34	413	-135	-875	-4	35	51	-47	-563	35	130
Net income (loss)	64	439	-108	-890	6	59	58	-21	-495	102	175
Net income (loss) attributable to Parent									-495	102	175
Duke Energy Indiana [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating revenues	792	790	748	845	747	755	700	724	3,175	2,926	2,717
Operating income (loss)	130	182	178	215	181	203	168	181	705	733	-75
Net income (loss)	58	101	87	113	82	104	82	90	359	358
Net income (loss) attributable to Parent									$359	$358	($50)

Quarterly_Financial_Data_Unaud3

Quarterly Financial Data (Unaudited) (Unusual or Infrequently Occurring Items) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Line Items]
Costs to achieve the merger	($33)	($56)	($61)	($55)	($72)	($88)	($82)	($55)	($205)	($297)
Pretax impairment charge									-81	-399	-666
Gain on sale of equity investment									17	100	22
Deferred foreign taxes									-67	14	20
Total	-547	421	-61	-1,436	-24	-88	-464	-55	-1,623	-631
Midwest Generation Impairment [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge	-39	477		-1,287					-849
Ash Basin [Member]
Quarterly Financial Information Disclosure [Line Items]
Coal ash Plea Agreements Reserve	-102								-102
International Tax Adjustment [Member]
Quarterly Financial Information Disclosure [Line Items]
Deferred foreign taxes	-373								-373
OVEC [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge				-94					-94
DukeNet [Member]
Quarterly Financial Information Disclosure [Line Items]
Gain on sale of equity investment					105					105
Crystal River Unit 3 Retirement [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge					-57		-295			-352
Nuclear Development Charges [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge							-87			-87
Duke Energy Carolinas [Member]
Quarterly Financial Information Disclosure [Line Items]
Costs to achieve the merger	-17	-25	-38	-29	-29	-34	-35	-22	-109	-120
Pretax impairment charge									-3		-31
Total	-89	-25	-38	-29					-181
Duke Energy Carolinas [Member] | Ash Basin [Member]
Quarterly Financial Information Disclosure [Line Items]
Coal ash Plea Agreements Reserve	-72								-72
Progress Energy [Member]
Quarterly Financial Information Disclosure [Line Items]
Costs to achieve the merger	-13	-21	-12	-19	-28	-42	-33	-19	-65	-122
Pretax impairment charge									16	-380	-200
Total	-43	-21	-12	-19	-85	-42	-415	-19	-95	-561
Progress Energy [Member] | Ash Basin [Member]
Quarterly Financial Information Disclosure [Line Items]
Coal ash Plea Agreements Reserve	-30								-30
Progress Energy [Member] | Crystal River Unit 3 Retirement [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge					-57		-295			-352
Progress Energy [Member] | Nuclear Development Charges [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge							-87			-87
Duke Energy Progress [Member]
Quarterly Financial Information Disclosure [Line Items]
Costs to achieve the merger	-10	-15	-3	-14	-19	-32	-22	-11	-42	-84
Pretax impairment charge									18	-22	-54
Total	-40	-15	-3	-14	-19	-32	-44	-11	-72	-106
Duke Energy Progress [Member] | Ash Basin [Member]
Quarterly Financial Information Disclosure [Line Items]
Coal ash Plea Agreements Reserve	-30								-30
Duke Energy Progress [Member] | Nuclear Development Charges [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge							-22			-22
Duke Energy Florida [Member]
Quarterly Financial Information Disclosure [Line Items]
Costs to achieve the merger	-3	-6	-9	-5	-9	-10	-11	-8	-23	-38
Pretax impairment charge									-2	-358	-146
Total					-66	-10	-371	-8		-455
Duke Energy Florida [Member] | Crystal River Unit 3 Retirement [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge					-57		-295			-352
Duke Energy Florida [Member] | Nuclear Development Charges [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge							-65			-65
Duke Energy Ohio [Member]
Quarterly Financial Information Disclosure [Line Items]
Costs to achieve the merger	-2	-3	-4	-2	-4	-4	-4	-4	-11	-16
Pretax impairment charge									-94	-5	-2
Total	-41	474	-4	-1,414					-985
Duke Energy Ohio [Member] | Midwest Generation Impairment [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge	-39	477		-1,318					-880
Duke Energy Ohio [Member] | OVEC [Member]
Quarterly Financial Information Disclosure [Line Items]
Pretax impairment charge				-94					-94
Duke Energy Indiana [Member]
Quarterly Financial Information Disclosure [Line Items]
Costs to achieve the merger	-2	-3	-5	-2	-5	-5	-5	-4	-12	-19
Pretax impairment charge									$0	$0	($579)