Louisville Gas & Electric 10-K 22 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document Entity Information [Line Items]
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Entity Registrant Name	PPL Corp
Entity Central Index Key	922,224
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 26,500,381,927
Entity Common Stock, Shares Outstanding		694,049,792
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
PPL Electric Utilities Corp [Member]
Document Entity Information [Line Items]
Amendment Flag	false
Entity Registrant Name	PPL ELECTRIC UTILITIES CORP
Entity Central Index Key	317,187
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		66,368,056
LG And E And KU Energy LLC [Member]
Document Entity Information [Line Items]
Amendment Flag	false
Entity Registrant Name	LG&E & KU Energy LLC
Entity Central Index Key	1,518,339
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Louisville Gas And Electric Co [Member]
Document Entity Information [Line Items]
Amendment Flag	false
Entity Registrant Name	LOUISVILLE GAS & ELECTRIC CO
Entity Central Index Key	60,549
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		21,294,223
Kentucky Utilities Co [Member]
Document Entity Information [Line Items]
Amendment Flag	false
Entity Registrant Name	KENTUCKY UTILITIES CO
Entity Central Index Key	55,387
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		37,817,878

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Revenues
Operating Revenues		$ 7,447	$ 7,517	$ 7,669
Operation
Fuel		759	791	863
Energy purchases		685	706	855
Other operation and maintenance		1,635	1,745	1,938
Depreciation		1,008	926	883
Taxes, other than income		292	301	299
Total Operating Expenses		4,379	4,469	4,838
Operating Income		3,068	3,048	2,831
Other Income (Expense) - net		(255)	390	108
Interest Expense		901	888	871
Income Before Income Taxes		1,912	2,550	2,068
Income Taxes		784	648	465
Income from continuing operations (net of income taxes)		1,128	1,902	1,603
Loss from Discontinued Operations (net of income taxes)		0	0	(921)
Net income		$ 1,128	$ 1,902	$ 682
Income from Continuing Operations After Income Taxes Available to PPL Common Shareholders
Basic (in dollars per share)		$ 1.64	$ 2.80	$ 2.38
Diluted (in dollars per share)		1.64	2.79	2.37
Net Income Available to PPL Common Shareowners
Basic (in dollars per share)		1.64	2.80	1.01
Diluted (in dollars per share)		1.64	2.79	1.01
Dividends Declared Per Share of Common Stock		$ 1.58	$ 1.52	$ 1.50
Weighted-Average Shares of Common Stock Outstanding (in thousands)
Basic		685,240	677,592	669,814
Diluted		687,334	680,446	672,586
PPL Electric Utilities Corp [Member]
Operating Revenues
Operating Revenues		$ 2,195	$ 2,156	$ 2,124
Operation
Energy purchases		507	535	657
Energy purchases from affiliate		0	0	14
Other operation and maintenance		571	599	607
Depreciation		309	253	214
Taxes, other than income		107	105	94
Total Operating Expenses		1,494	1,492	1,586
Operating Income		701	664	538
Other Income (Expense) - net		11	17	8
Interest Income from Affiliate		5	0	0
Interest Expense		142	129	130
Income Before Income Taxes		575	552	416
Income Taxes		213	212	164
Net income	[1]	362	340	252
LG And E And KU Energy LLC [Member]
Operating Revenues
Operating Revenues		3,156	3,141	3,115
Operation
Fuel		759	791	863
Energy purchases		178	171	184
Other operation and maintenance		806	804	837
Depreciation		439	404	382
Taxes, other than income		65	62	57
Total Operating Expenses		2,247	2,232	2,323
Operating Income		909	909	792
Other Income (Expense) - net		(3)	(9)	(8)
Interest Expense		197	197	178
Interest Expense with Affiliates		18	17	3
Income Before Income Taxes		691	686	603
Income Taxes		375	257	239
Net income		316	429	364
Louisville Gas And Electric Co [Member]
Operating Revenues
Retail and wholesale		1,422	1,406	1,407
Electric revenue from affiliates		31	24	37
Operating Revenues		1,453	1,430	1,444
Operation
Fuel		292	301	329
Energy purchases		160	153	166
Energy purchases from affiliate		10	14	20
Other operation and maintenance		355	355	377
Depreciation		183	170	162
Taxes, other than income		33	32	28
Total Operating Expenses		1,033	1,025	1,082
Operating Income		420	405	362
Other Income (Expense) - net		(5)	(5)	(6)
Interest Expense		71	71	57
Income Before Income Taxes		344	329	299
Income Taxes		131	126	114
Net income	[2]	213	203	185
Kentucky Utilities Co [Member]
Operating Revenues
Retail and wholesale		1,734	1,735	1,708
Electric revenue from affiliates		10	14	20
Operating Revenues		1,744	1,749	1,728
Operation
Fuel		467	490	534
Energy purchases		18	18	18
Energy purchases from affiliate		31	24	37
Other operation and maintenance		424	424	435
Depreciation		255	234	220
Taxes, other than income		32	30	29
Total Operating Expenses		1,227	1,220	1,273
Operating Income		517	529	455
Other Income (Expense) - net		(3)	(5)	1
Interest Expense		96	96	82
Income Before Income Taxes		418	428	374
Income Taxes		159	163	140
Net income	[3]	$ 259	$ 265	$ 234
[1]	Net income equals comprehensive income.
[2]	Net income equals comprehensive income.
[3]	Net income approximates comprehensive income.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income		$ 1,128	$ 1,902	$ 682
Amounts arising during the period - gains (losses), net of tax (expense) benefit:
Foreign currency translation adjustments, net of tax		538	(1,107)	(234)
Available-for-sale securities, net of tax		0	0	8
Qualifying derivatives, net of tax		(79)	91	26
Defined benefit plans:
Prior service costs, net of tax		0	(3)	(9)
Net actuarial gain (loss), net of tax		(308)	(61)	(366)
Reclassifications to net income - (gains) losses, net of tax expense (benefit):
Available-for-sale securities, net of tax		0	0	(2)
Qualifying derivatives, net of tax		73	(91)	2
Equity investees' other comprehensive (income) loss, net of tax		1	(1)	(1)
Defined benefit plans:
Prior service costs, net of tax		1	1	0
Net actuarial (gain) loss, net of tax		130	121	146
Total other comprehensive income (loss)		356	(1,050)	(430)
Comprehensive income		1,484	852	252
PPL Electric Utilities Corp [Member]
Net income	[1]	362	340	252
LG And E And KU Energy LLC [Member]
Net income		316	429	364
Defined benefit plans:
Prior service costs, net of tax		(2)	0	(3)
Net actuarial gain (loss), net of tax		(23)	(27)	(4)
Reclassifications to net income - (gains) losses, net of tax expense (benefit):
Equity investees' other comprehensive (income) loss, net of tax		1	(1)	0
Defined benefit plans:
Prior service costs, net of tax		1	2	1
Net actuarial (gain) loss, net of tax		5	2	5
Total other comprehensive income (loss)		(18)	(24)	(1)
Comprehensive income		298	405	363
Louisville Gas And Electric Co [Member]
Net income	[2]	213	203	185
Kentucky Utilities Co [Member]
Net income	[3]	259	265	$ 234
Defined benefit plans:
Total other comprehensive income (loss)		$ 1	$ (1)
[1]	Net income equals comprehensive income.
[2]	Net income equals comprehensive income.
[3]	Net income approximates comprehensive income.

CONSOLIDATED STATEMENTS OF COM4

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax effect of foreign currency translation adjustments arising during the period	$ (1)	$ (4)	$ 1
Tax effect of available-for-sale securities arising during the period	0	0	(9)
Tax effect of qualifying derivatives arising during the period	19	(18)	0
Tax effect of defined benefit plans - prior service costs arising during period	0	2	6
Tax effect of defined benefit plans - net actuarial gain (loss) arising during period	72	40	67
Tax effect of available-for-sale securities reclassified to net income	0	0	2
Tax effect of qualifying derivatives reclassified to net income	(18)	21	(15)
Tax effect of equity investees' other comprehensive (income) loss reclassified to net income	0	0	0
Tax effect of defined benefit plans - prior service costs reclassified to net income	(1)	(1)	0
Tax effect of defined benefit plans - net actuarial (gain) loss reclassified to net income	(37)	(35)	(46)
LG And E And KU Energy LLC [Member]
Tax effect of defined benefit plans - prior service costs arising during period	(1)	0	(2)
Tax effect of defined benefit plans - net actuarial gain (loss) arising during period	13	18	2
Tax effect of equity investees' other comprehensive (income) loss reclassified to net income	0	0	0
Tax effect of defined benefit plans - prior service costs reclassified to net income	1	1	1
Tax effect of defined benefit plans - net actuarial (gain) loss reclassified to net income	$ 2	$ 1	$ 3

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities
Net income		$ 1,128	$ 1,902	$ 682
Loss from Discontinued Operations (net of income taxes)		0	0	921
Income from continuing operations (net of income taxes)		1,128	1,902	1,603
Adjustments to reconcile income from continuing operations (net of taxes) to net cash provided by (used in) operating activities - continuing operations
Depreciation		1,008	926	883
Amortization		97	80	59
Defined benefit plans - expense (income)		(95)	(40)	56
Deferred income taxes and investment tax credits		707	560	428
Unrealized (gains) losses on derivatives, and other hedging activities		178	19	(77)
Stock compensation expense		38	28	31
Other		(9)	(12)	(14)
Change in current assets and current liabilities
Accounts receivable		(33)	(15)	47
Accounts payable		(10)	57	(116)
Unbilled Revenues		(48)	(63)	54
Fuel, materials and supplies		40	(3)	24
Taxes payable		3	31	(175)
Regulatory assets and liabilities		(12)	(59)	42
Other		14	(32)	(7)
Other operating activities
Defined benefit plans - funding		(565)	(427)	(499)
Settlement of interest rate swaps		2	(9)	(101)
Other assets		30	42	(19)
Other liabilities		(12)	(95)	53
Net cash provided by operating activities - continuing operations		2,461	2,890	2,272
Net cash provided by operating activities - discontinued operations		0	0	343
Net cash provided by (used in) operating activities		2,461	2,890	2,615
Cash Flows from Investing Activities
Expenditures for property, plant and equipment		(3,133)	(2,920)	(3,533)
Expenditures for intangible assets		(38)	(37)	(37)
Proceeds from the sale of other investments		0	2	136
Other investing activities		15	37	(5)
Net cash used in investing activities - continuing operations		(3,156)	(2,918)	(3,439)
Net cash used in investing activities - discontinued operations		0	0	(149)
Net cash provided by (used in) investing activities		(3,156)	(2,918)	(3,588)
Cash Flows from Financing Activities
Issuance of long-term debt		1,515	1,342	2,236
Retirement of long-term debt		(168)	(930)	(1,000)
Issuance of common stock		453	144	203
Payment of common stock dividends		(1,072)	(1,030)	(1,004)
Net increase (decrease) in short-term debt		115	29	94
Other financing activities		(19)	6	(47)
Net cash used in financing activities - discontinued operations		0	0	(546)
Net cash distributions to parent from discontinued operations		0		132
Net cash provided by (used in) financing activities		824	(439)	68
Effect of Exchange Rates on Cash and Cash Equivalents		15	(28)	(10)
Net (Increase) Decrease in Cash and Cash Equivalents included in Discontinued Operations		0	0	352
Net Increase (Decrease) in Cash and Cash Equivalents		144	(495)	(563)
Cash and Cash Equivalents at Beginning of Period		341	836	1,399
Cash and Cash Equivalents at End of Period		485	341	836
Supplemental Disclosures of Cash Flow Information:
Interest - net of amount capitalized		845	854	822
Income taxes - net		65	70	179
Accrued expenditures for property, plant and equipment at December 31,		360	281	310
Accrued expenditures for intangible assets at December 31,		68	117	55
PPL Electric Utilities Corp [Member]
Cash Flows from Operating Activities
Net income	[1]	362	340	252
Adjustments to reconcile income from continuing operations (net of taxes) to net cash provided by (used in) operating activities - continuing operations
Depreciation		309	253	214
Amortization		33	32	26
Defined benefit plans - expense (income)		12	11	16
Deferred income taxes and investment tax credits		258	221	220
Other		(8)	(13)	(12)
Change in current assets and current liabilities
Accounts receivable		(57)	16	50
Accounts payable		3	58	(107)
Unbilled Revenues		(13)	(23)	22
Prepayments		3	43	(1)
Taxes payable		(4)	(12)	(108)
Regulatory assets and liabilities		(5)	(62)	35
Other		(1)	(7)	21
Other operating activities
Defined benefit plans - funding		(24)	0	(33)
Other assets		15	19	(10)
Other liabilities		(3)	(4)	17
Net cash provided by (used in) operating activities		880	872	602
Cash Flows from Investing Activities
Expenditures for property, plant and equipment		(1,244)	(1,125)	(1,097)
Expenditures for intangible assets		(10)	(9)	(10)
Other investing activities		2	4	(1)
Net cash provided by (used in) investing activities		(1,252)	(1,130)	(1,108)
Cash Flows from Financing Activities
Issuance of long-term debt		470	224	348
Retirement of long-term debt		0	(224)	(100)
Contributions from parent		575	220	275
Payment of common stock dividends to parent		(336)	(288)	(181)
Net increase (decrease) in short-term debt		(295)	295	0
Other financing activities		(6)	(3)	(3)
Net cash provided by (used in) financing activities		408	224	339
Net Increase (Decrease) in Cash and Cash Equivalents		36	(34)	(167)
Cash and Cash Equivalents at Beginning of Period		13	47	214
Cash and Cash Equivalents at End of Period		49	13	47
Supplemental Disclosures of Cash Flow Information:
Interest - net of amount capitalized		128	115	117
Income taxes - net		4	(48)	38
Accrued expenditures for property, plant and equipment at December 31,		133	126	98
LG And E And KU Energy LLC [Member]
Cash Flows from Operating Activities
Net income		316	429	364
Adjustments to reconcile income from continuing operations (net of taxes) to net cash provided by (used in) operating activities - continuing operations
Depreciation		439	404	382
Amortization		24	29	27
Defined benefit plans - expense (income)		25	27	38
Deferred income taxes and investment tax credits		294	291	236
Other		0	0	2
Change in current assets and current liabilities
Accounts receivable		(12)	(31)	24
Accounts payable		(9)	24	(58)
Unbilled Revenues		(33)	(23)	20
Accounts payable to affiliates		2	1	(2)
Fuel, materials and supplies		45	2	6
Income tax receivable		0	1	135
Taxes payable		27	(7)	10
Accrued interest		0	0	9
Other		34	(6)	23
Other operating activities
Defined benefit plans - funding		(35)	(85)	(70)
Settlement of interest rate swaps		0	(9)	(88)
Expenditures for asset retirement obligations		(34)	(26)	(7)
Other assets		8	2	(7)
Other liabilities		8	4	19
Net cash provided by (used in) operating activities		1,099	1,027	1,063
Cash Flows from Investing Activities
Expenditures for property, plant and equipment		(892)	(791)	(1,210)
Other investing activities		4	1	7
Net cash provided by (used in) investing activities		(888)	(790)	(1,203)
Cash Flows from Financing Activities
Issuance of long-term debt		160	221	1,050
Issuance of long-term note with affiliate		0	0	400
Retirement of long-term debt		(70)	(246)	(900)
Contributions from member		0	61	125
Distributions to member		(402)	(316)	(219)
Net increase (decrease) in notes payable to affiliates		62	109	13
Net increase (decrease) in short-term debt		59	(80)	(310)
Other financing activities		(3)	(3)	(10)
Net cash provided by (used in) financing activities		(194)	(254)	149
Net Increase (Decrease) in Cash and Cash Equivalents		17	(17)	9
Cash and Cash Equivalents at Beginning of Period		13	30	21
Cash and Cash Equivalents at End of Period		30	13	30
Supplemental Disclosures of Cash Flow Information:
Interest - net of amount capitalized		204	198	163
Income taxes - net		48	(24)	(139)
Accrued expenditures for property, plant and equipment at December 31,		174	104	150
Louisville Gas And Electric Co [Member]
Cash Flows from Operating Activities
Net income	[2]	213	203	185
Adjustments to reconcile income from continuing operations (net of taxes) to net cash provided by (used in) operating activities - continuing operations
Depreciation		183	170	162
Amortization		14	14	11
Defined benefit plans - expense (income)		7	8	12
Deferred income taxes and investment tax credits		126	147	126
Other		1	0	8
Change in current assets and current liabilities
Accounts receivable		(7)	(22)	19
Accounts receivable from affiliates		4	(16)	11
Accounts payable		(7)	31	(29)
Unbilled Revenues		(16)	(8)	9
Accounts payable to affiliates		(4)	1	5
Fuel, materials and supplies		12	8	3
Income tax receivable		0	4	70
Taxes payable		(15)	20	1
Accrued interest		0	0	5
Other		11	(7)	17
Other operating activities
Defined benefit plans - funding		(4)	(46)	(26)
Settlement of interest rate swaps		0	(9)	(44)
Expenditures for asset retirement obligations		(15)	(18)	(6)
Other assets		5	0	11
Other liabilities		4	2	4
Net cash provided by (used in) operating activities		512	482	554
Cash Flows from Investing Activities
Expenditures for property, plant and equipment		(458)	(439)	(689)
Net cash provided by (used in) investing activities		(458)	(439)	(689)
Cash Flows from Financing Activities
Issuance of long-term debt		160	125	550
Retirement of long-term debt		(70)	(150)	(250)
Contributions from parent		30	71	90
Payment of common stock dividends to parent		(192)	(128)	(119)
Net increase (decrease) in short-term debt		30	27	(122)
Other financing activities		(2)	(2)	(5)
Net cash provided by (used in) financing activities		(44)	(57)	144
Net Increase (Decrease) in Cash and Cash Equivalents		10	(14)	9
Cash and Cash Equivalents at Beginning of Period		5	19	10
Cash and Cash Equivalents at End of Period		15	5	19
Supplemental Disclosures of Cash Flow Information:
Interest - net of amount capitalized		65	65	48
Income taxes - net		22	(43)	(81)
Accrued expenditures for property, plant and equipment at December 31,		92	56	97
Kentucky Utilities Co [Member]
Cash Flows from Operating Activities
Net income	[3]	259	265	234
Adjustments to reconcile income from continuing operations (net of taxes) to net cash provided by (used in) operating activities - continuing operations
Depreciation		255	234	220
Amortization		9	14	13
Defined benefit plans - expense (income)		4	5	10
Deferred income taxes and investment tax credits		152	126	160
Other		0	(1)	(5)
Change in current assets and current liabilities
Accounts receivable		(5)	(8)	5
Accounts receivable from affiliates		0	1	(1)
Accounts payable		0	(10)	(32)
Unbilled Revenues		(17)	(15)	11
Accounts payable to affiliates		(6)	15	(10)
Fuel, materials and supplies		32	(6)	3
Income tax receivable		0	0	59
Taxes payable		(26)	25	6
Accrued interest		0	0	5
Other		7	(3)	4
Other operating activities
Defined benefit plans - funding		(23)	(20)	(21)
Settlement of interest rate swaps		0	0	(44)
Expenditures for asset retirement obligations		(19)	(8)	(1)
Other assets		3	(6)	(11)
Other liabilities		9	(2)	3
Net cash provided by (used in) operating activities		634	606	608
Cash Flows from Investing Activities
Expenditures for property, plant and equipment		(432)	(350)	(519)
Other investing activities		4	1	7
Net cash provided by (used in) investing activities		(428)	(349)	(512)
Cash Flows from Financing Activities
Issuance of long-term debt		0	96	500
Retirement of long-term debt		0	(96)	(250)
Contributions from parent		0	20	0
Payment of common stock dividends to parent		(226)	(248)	(153)
Net increase (decrease) in short-term debt		29	(32)	(188)
Other financing activities		(1)	(1)	(5)
Net cash provided by (used in) financing activities		(198)	(261)	(96)
Net Increase (Decrease) in Cash and Cash Equivalents		8	(4)	0
Cash and Cash Equivalents at Beginning of Period		7	11	11
Cash and Cash Equivalents at End of Period		15	7	11
Supplemental Disclosures of Cash Flow Information:
Interest - net of amount capitalized		92	89	75
Income taxes - net		34	13	(84)
Accrued expenditures for property, plant and equipment at December 31,		$ 82	$ 47	$ 53
[1]	Net income equals comprehensive income.
[2]	Net income equals comprehensive income.
[3]	Net income approximates comprehensive income.

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents		$ 485	$ 341
Accounts receivable (less reserve:)
Customer		681	666
Other		100	46
Unbilled revenues		543	480
Fuel, materials and supplies		320	356
Prepayments		66	63
Price risk management assets		49	63
Regulatory assets		34	39
Other current assets		50	52
Total Current Assets		2,294	2,067
Property, Plant and Equipment
Regulated utility plant		38,228	34,674
Less: accumulated depreciation - regulated utility plant		6,785	6,013
Regulated utility plant, net		31,443	28,661
Non-regulated property, plant and equipment		384	413
Less: accumulated depreciation - non-regulated property, plant and equipment		110	134
Non-regulated property, plant and equipment, net		274	279
Construction work in progress		1,375	1,134
Property, Plant and Equipment, net		33,092	30,074
Other Noncurrent Assets
Regulatory assets		1,504	1,918
Goodwill		3,258	3,060
Other intangibles		697	700
Pension benefit asset		284	9
Price risk management assets		215	336
Other noncurrent assets		135	151
Total Other Noncurrent Assets		6,093	6,174
Total Assets		41,479	38,315
Current Liabilities
Short-term debt		1,080	923
Long-term debt due within one year		348	518
Accounts payable		924	820
Taxes		105	101
Interest		282	270
Dividends		273	259
Customer deposits		292	276
Regulatory liabilities		95	101
Other current liabilities		624	569
Total Current Liabilities		4,023	3,837
Long-term Debt [Abstract]
Long-term Debt		19,847	17,808
Deferred Credits and Other Noncurrent Liabilities
Deferred income taxes		2,462	3,889
Investment tax credits		129	132
Accrued pension obligations		800	1,001
Asset retirement obligations		312	428
Regulatory liabilities		2,704	899
Other deferred credits and noncurrent liabilities		441	422
Total Deferred Credits and Other Noncurrent Liabilities		6,848	6,771
Commitments and Contingent Liabilities
Equity
Common stock	[1]	7	7
Additional paid-in capital		10,305	9,841
Earnings reinvested		3,871	3,829
Accumulated other comprehensive loss		(3,422)	(3,778)
Total Equity		10,761	9,899
Total Liabilities and Equity		41,479	38,315
PPL Electric Utilities Corp [Member]
Current Assets
Cash and cash equivalents		49	13
Accounts receivable (less reserve:)
Customer		279	272
Other		71	21
Unbilled revenues		127	114
Fuel, materials and supplies		34	32
Prepayments		6	9
Regulatory assets		16	19
Other current assets		6	8
Total Current Assets		588	488
Property, Plant and Equipment
Regulated utility plant		10,785	9,654
Less: accumulated depreciation - regulated utility plant		2,778	2,714
Regulated utility plant, net		8,007	6,940
Construction work in progress		508	641
Property, Plant and Equipment, net		8,515	7,581
Other Noncurrent Assets
Regulatory assets		709	1,094
Other intangibles		259	251
Other noncurrent assets		11	12
Total Other Noncurrent Assets		979	1,357
Total Assets		10,082	9,426
Current Liabilities
Short-term debt		0	295
Long-term debt due within one year		0	224
Accounts payable		386	367
Accounts payable to affiliates		31	42
Taxes		8	12
Interest		36	34
Regulatory liabilities		86	83
Other current liabilities		98	101
Total Current Liabilities		645	1,158
Long-term Debt [Abstract]
Long-term Debt		3,298	2,607
Deferred Credits and Other Noncurrent Liabilities
Deferred income taxes		1,154	1,899
Accrued pension obligations		246	281
Regulatory liabilities		668	0
Other deferred credits and noncurrent liabilities		79	90
Total Deferred Credits and Other Noncurrent Liabilities		2,147	2,270
Commitments and Contingent Liabilities
Equity
Common stock	[2]	364	364
Additional paid-in capital		2,729	2,154
Earnings reinvested		899	873
Total Equity		3,992	3,391
Total Liabilities and Equity		10,082	9,426
LG And E And KU Energy LLC [Member]
Current Assets
Cash and cash equivalents		30	13
Accounts receivable (less reserve:)
Customer		246	235
Other		44	17
Unbilled revenues		203	170
Fuel, materials and supplies		254	297
Prepayments		25	24
Regulatory assets		18	20
Other current assets		8	4
Total Current Assets		828	780
Property, Plant and Equipment
Regulated utility plant		13,187	12,746
Less: accumulated depreciation - regulated utility plant		1,785	1,465
Regulated utility plant, net		11,402	11,281
Construction work in progress		627	317
Property, Plant and Equipment, net		12,029	11,598
Other Noncurrent Assets
Regulatory assets		795	824
Goodwill		996	996
Other intangibles		86	95
Other noncurrent assets		68	78
Total Other Noncurrent Assets		1,945	1,993
Total Assets		14,802	14,371
Current Liabilities
Short-term debt		244	185
Long-term debt due within one year		98	194
Notes payable with affiliates		225	163
Accounts payable		338	251
Accounts payable to affiliates		7	6
Taxes		66	39
Interest		32	32
Asset Retirement Obligations		85	60
Price risk management liabilities		4	4
Customer deposits		58	56
Regulatory liabilities		9	18
Other current liabilities		161	119
Total Current Liabilities		1,327	1,127
Long-term Debt [Abstract]
Long-term debt		4,661	4,471
Long-term debt to affiliate		400	400
Long-term Debt		5,061	4,871
Deferred Credits and Other Noncurrent Liabilities
Deferred income taxes		866	1,735
Investment tax credits		129	132
Price risk management liabilities		22	27
Accrued pension obligations		365	350
Asset retirement obligations		271	373
Regulatory liabilities		2,036	899
Other deferred credits and noncurrent liabilities		162	190
Total Deferred Credits and Other Noncurrent Liabilities		3,851	3,706
Commitments and Contingent Liabilities
Equity
Accumulated other comprehensive loss		(88)	(70)
Member's Equity		4,563	4,667
Total Liabilities and Equity		14,802	14,371
Louisville Gas And Electric Co [Member]
Current Assets
Cash and cash equivalents		15	5
Accounts receivable (less reserve:)
Customer		116	109
Other		13	11
Accounts receivable from affiliates		24	28
Unbilled revenues		91	75
Fuel, materials and supplies		131	143
Prepayments		11	12
Regulatory assets		12	9
Other current assets		3	1
Total Current Assets		416	393
Property, Plant and Equipment
Regulated utility plant		5,587	5,357
Less: accumulated depreciation - regulated utility plant		614	498
Regulated utility plant, net		4,973	4,859
Construction work in progress		305	133
Property, Plant and Equipment, net		5,278	4,992
Other Noncurrent Assets
Regulatory assets		411	450
Goodwill		389	389
Other intangibles		53	59
Other noncurrent assets		12	17
Total Other Noncurrent Assets		865	915
Total Assets		6,559	6,300
Current Liabilities
Short-term debt		199	169
Long-term debt due within one year		98	194
Accounts payable		179	148
Accounts payable to affiliates		23	26
Taxes		25	40
Interest		11	11
Asset Retirement Obligations		24	41
Price risk management liabilities		4	4
Customer deposits		27	27
Regulatory liabilities		3	5
Other current liabilities		52	36
Total Current Liabilities		645	701
Long-term Debt [Abstract]
Long-term Debt		1,611	1,423
Deferred Credits and Other Noncurrent Liabilities
Deferred income taxes		572	974
Investment tax credits		35	36
Price risk management liabilities		22	27
Accrued pension obligations		45	53
Asset retirement obligations		97	104
Regulatory liabilities		919	419
Other deferred credits and noncurrent liabilities		86	87
Total Deferred Credits and Other Noncurrent Liabilities		1,776	1,700
Commitments and Contingent Liabilities
Equity
Common stock	[3]	424	424
Additional paid-in capital		1,712	1,682
Earnings reinvested		391	370
Total Equity		2,527	2,476
Total Liabilities and Equity		6,559	6,300
Kentucky Utilities Co [Member]
Current Assets
Cash and cash equivalents		15	7
Accounts receivable (less reserve:)
Customer		130	126
Other		30	5
Unbilled revenues		112	95
Fuel, materials and supplies		123	154
Prepayments		14	12
Regulatory assets		6	11
Other current assets		5	3
Total Current Assets		435	413
Property, Plant and Equipment
Regulated utility plant		7,592	7,382
Less: accumulated depreciation - regulated utility plant		1,170	965
Regulated utility plant, net		6,422	6,417
Construction work in progress		321	181
Property, Plant and Equipment, net		6,743	6,598
Other Noncurrent Assets
Regulatory assets		384	374
Goodwill		607	607
Other intangibles		33	36
Other noncurrent assets		52	57
Total Other Noncurrent Assets		1,076	1,074
Total Assets		8,254	8,085
Current Liabilities
Short-term debt		45	16
Long-term debt due within one year		0	0
Accounts payable		137	78
Accounts payable to affiliates		53	56
Taxes		19	45
Interest		16	16
Asset Retirement Obligations		61	19
Customer deposits		31	29
Regulatory liabilities		6	13
Other current liabilities		46	36
Total Current Liabilities		414	308
Long-term Debt [Abstract]
Long-term Debt		2,328	2,327
Deferred Credits and Other Noncurrent Liabilities
Deferred income taxes		691	1,170
Investment tax credits		94	96
Accrued pension obligations		36	62
Asset retirement obligations		174	269
Regulatory liabilities		1,117	480
Other deferred credits and noncurrent liabilities		43	50
Total Deferred Credits and Other Noncurrent Liabilities		2,155	2,127
Commitments and Contingent Liabilities
Equity
Common stock	[4]	308	308
Additional paid-in capital		2,616	2,616
Earnings reinvested		433	400
Accumulated other comprehensive loss		0	(1)
Total Equity		3,357	3,323
Total Liabilities and Equity		$ 8,254	$ 8,085
[1]	1,560,000 shares authorized; 693,398 and 679,731 shares issued and outstanding at December 31, 2017 and December 31, 2016.
[2]	170,000 shares authorized; 66,368 shares issued and outstanding at December 31, 2017 and December 31, 2016
[3]	75,000 shares authorized; 21,294 shares issued and outstanding at December 31, 2017 and December 31, 2016.
[4]	80,000 shares authorized; 37,818 shares issued and outstanding at December 31, 2017 and December 31, 2016.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Receivables Net Current [Abstract]
Accounts receivable reserve for uncollectible accounts	$ 51	$ 54
Equity
Common stock par value	$ 0.01	$ 0.01
Common stock shares authorized	1,560,000	1,560,000
Common stock shares issued	693,398	679,731
Common stock shares outstanding	693,398	679,731
PPL Electric Utilities Corp [Member]
Receivables Net Current [Abstract]
Accounts receivable reserve for uncollectible accounts	$ 24	$ 28
Equity
Common stock no par value	$ 0	$ 0
Common stock shares authorized	170,000	170,000
Common stock shares issued	66,368	66,368
Common stock shares outstanding	66,368	66,368
LG And E And KU Energy LLC [Member]
Receivables Net Current [Abstract]
Accounts receivable reserve for uncollectible accounts	$ 25	$ 24
Louisville Gas And Electric Co [Member]
Receivables Net Current [Abstract]
Accounts receivable reserve for uncollectible accounts	$ 1	$ 2
Equity
Common stock no par value	$ 0	$ 0
Common stock shares authorized	75,000	75,000
Common stock shares issued	21,294	21,294
Common stock shares outstanding	21,294	21,294
Kentucky Utilities Co [Member]
Receivables Net Current [Abstract]
Accounts receivable reserve for uncollectible accounts	$ 1	$ 2
Equity
Common stock no par value	$ 0	$ 0
Common stock shares authorized	80,000	80,000
Common stock shares issued	37,818	37,818
Common stock shares outstanding	37,818	37,818

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Millions		Total	Common Stock		Additional Paid-in Capital	Earnings Reinvested	Accumulated Other Comprehensive Loss	PPL Electric Utilities Corp [Member]		PPL Electric Utilities Corp [Member]Common Stock		PPL Electric Utilities Corp [Member]Additional Paid-in Capital		PPL Electric Utilities Corp [Member]Earnings Reinvested	LG And E And KU Energy LLC [Member]	Louisville Gas And Electric Co [Member]		Louisville Gas And Electric Co [Member]Common Stock		Louisville Gas And Electric Co [Member]Additional Paid-in Capital	Louisville Gas And Electric Co [Member]Earnings Reinvested	Kentucky Utilities Co [Member]		Kentucky Utilities Co [Member]Common Stock		Kentucky Utilities Co [Member]Additional Paid-in Capital	Kentucky Utilities Co [Member]Earnings Reinvested	Kentucky Utilities Co [Member]Accumulated Other Comprehensive Loss
Balance at beginning of period - shares at Dec. 31, 2014			665,849	[1]						66,368	[2]							21,294	[3]					37,818	[4]
Balance at beginning of period at Dec. 31, 2014															$ 4,248
Balance at beginning of period at Dec. 31, 2014		$ 13,628	$ 7		$ 9,433	$ 6,462	$ (2,274)	$ 2,717		$ 364		$ 1,603		$ 750		$ 2,174		$ 424		$ 1,521	$ 229	$ 3,206		$ 308		$ 2,596	$ 302	$ 0
Common stock shares issued	[1]		8,008
Common stock issued		249			249
Stock-based compensation		5			5
Net income		682				682		252	[5]					252	364	185	[6]				185	234	[7]				234
Capital contributions from parent								331	[8]			331	[8]			90				90
Dividends, dividend equivalents, redemptions and distributions		(1,010)				(1,010)
Cash dividends declared on common stock								(181)						(181)		(119)					(119)	(153)					(153)
Contributions from member															125
Distributions to member															(219)
Distribution of PPL Energy Supply		(3,205)				(3,181)	(24)
Other comprehensive income (loss)		(430)					(430)								(1)
Balance at end of period - shares at Dec. 31, 2015			673,857	[1]						66,368	[2]							21,294	[3]					37,818	[4]
Balance at end of period at Dec. 31, 2015															4,517
Balance at end of period at Dec. 31, 2015		9,919	$ 7		9,687	2,953	(2,728)	3,119		$ 364		1,934		821		2,330		$ 424		1,611	295	3,287		$ 308		2,596	383	0
Common stock shares issued	[1]		5,874
Common stock issued		185			185
Stock-based compensation		(31)			(31)
Net income		1,902				1,902		340	[5]					340	429	203	[6]				203	265	[7]				265
Capital contributions from parent								220				220				71				71		20				20
Dividends, dividend equivalents, redemptions and distributions		(1,033)				(1,033)
Cash dividends declared on common stock								$ (288)						(288)		$ (128)					(128)	(248)					(248)
Contributions from member															61
Distributions to member															(316)
Other comprehensive income (loss)		(1,050)					(1,050)								(24)							$ (1)						(1)
Adoption of stock-based compensation guidance cumulative effect adjustment		$ 7				7
Balance at end of period - shares at Dec. 31, 2016		679,731	679,731	[1]				66,368		66,368	[2]					21,294		21,294	[3]			37,818		37,818	[4]
Balance at end of period at Dec. 31, 2016															4,667
Balance at end of period at Dec. 31, 2016		$ 9,899	$ 7		9,841	3,829	(3,778)	$ 3,391		$ 364		2,154		873		$ 2,476		$ 424		1,682	370	$ 3,323		$ 308		2,616	400	(1)
Common stock shares issued	[1]		13,667
Common stock issued		482			482
Stock-based compensation		(18)			(18)
Net income		1,128				1,128		362	[5]					362	316	213	[6]				213	259	[7]				259
Capital contributions from parent								575				575				30				30
Dividends, dividend equivalents, redemptions and distributions		(1,086)				(1,086)
Cash dividends declared on common stock								$ (336)						(336)		$ (192)					(192)	(226)					(226)
Distributions to member															(402)
Other comprehensive income (loss)		$ 356					356								(18)							$ 1						1
Balance at end of period - shares at Dec. 31, 2017		693,398	693,398	[1]				66,368		66,368	[2]					21,294		21,294	[3]			37,818		37,818	[4]
Balance at end of period at Dec. 31, 2017															$ 4,563
Balance at end of period at Dec. 31, 2017		$ 10,761	$ 7		$ 10,305	$ 3,871	$ (3,422)	$ 3,992		$ 364		$ 2,729		$ 899		$ 2,527		$ 424		$ 1,712	$ 391	$ 3,357		$ 308		$ 2,616	$ 433	$ 0
[1]	Shares in thousands. Each share entitles the holder to one vote on any question presented at any shareowners' meeting.
[2]	Shares in thousands. All common shares of PPL Electric stock are owned by PPL.
[3]	Shares in thousands. All common shares of LG&E stock are owned by LKE.
[4]	Shares in thousands. All common shares of KU stock are owned by LKE.
[5]	Net income equals comprehensive income.
[6]	Net income equals comprehensive income.
[7]	Net income approximates comprehensive income.
[8]	Includes non-cash contributions of $56 million. See Note 11 for additional information.

CONSOLIDATED STATEMENTS OF EQU9

CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2017vote	Dec. 31, 2016vote	Dec. 31, 2015USD ($)vote
Vote per share of PPL's common stock | vote	1	1	1
PPL Electric Utilities Corp [Member]
Non-cash contributions related to remeasurement and separation of benefit plans | $			$ 56

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies (All Registrants) General Capitalized terms and abbreviations appearing in the combined notes to financial statements are defined in the glossary. Dollars are in millions, except per share data, unless otherwise noted. The specific Registrant to which disclosures are applicable is identified in parenthetical headings in italics above the applicable disclosure or within the applicable disclosure for each Registrants' related activities and disclosures. Within combined disclosures, amounts are disclosed for any Registrant when significant. Business and Consolidation (PPL) PPL is a utility holding company that, through its regulated subsidiaries, is primarily engaged in: 1) the distribution of electricity in the U.K.; 2) the generation, transmission, distribution and sale of electricity and the distribution and sale of natural gas, primarily in Kentucky; and 3) the transmission, distribution and sale of electricity in Pennsylvania. Headquartered in Allentown, PA, PPL's principal subsidiaries are PPL Global, LKE (including its principal subsidiaries, LG&E and KU) and PPL Electric. PPL's corporate level financing subsidiary is PPL Capital Funding. WPD, a subsidiary of PPL Global, through indirect, wholly owned subsidiaries, operates distribution networks providing electricity service in the U.K. WPD serves end-users in South Wales and southwest and central England. Its principal subsidiaries are WPD (South Wales), WPD (South West), WPD (East Midlands) and WPD (West Midlands). PPL consolidates WPD on a one -month lag. Material events, such as debt issuances that occur in the lag period, are recognized in the current period financial statements. Events that are significant but not material are disclosed. (PPL and PPL Electric) PPL Electric is a cost-based rate-regulated utility subsidiary of PPL. PPL Electric's principal business is the transmission and distribution of electricity to serve retail customers in its franchised territory in eastern and central Pennsylvania and the regulated supply of electricity to retail customers in that territory as a PLR. (PPL, LKE, LG&E and KU) LKE is a utility holding company with cost-based rate-regulated utility operations through its subsidiaries, LG&E and KU. LG&E and KU are engaged in the generation, transmission, distribution and sale of electricity. LG&E also engages in the distribution and sale of natural gas. LG&E and KU maintain their separate identities and serve customers in Kentucky under their respective names. KU also serves customers in Virginia under the Old Dominion Power name and in Tennessee under the KU name. (PPL) "Loss from Discontinued Operations (net of income taxes)" on the 2015 Statement of Income includes the activities of PPL Energy Supply, substantially representing PPL's former Supply segment, which was spun off and distributed to PPL shareowners on June 1, 2015. In addition, the Statement of Cash Flows for the same period separately reports the cash flows of the discontinued operations. See Note 8 for additional information. (All Registrants) The financial statements of the Registrants include each company's own accounts as well as the accounts of all entities in which the company has a controlling financial interest. Entities for which a controlling financial interest is not demonstrated through voting interests are evaluated based on accounting guidance for Variable Interest Entities (VIEs). The Registrants consolidate a VIE when they are determined to have a controlling interest in the VIE, and as a result are the primary beneficiary of the entity. The Registrants are not the primary beneficiary in any VIEs. Investments in entities in which a company has the ability to exercise significant influence but does not have a controlling financial interest are accounted for under the equity method. All other investments are carried at cost or fair value. All significant intercompany transactions have been eliminated. The financial statements of PPL, LKE, LG&E and KU include their share of any undivided interests in jointly owned facilities, as well as their share of the related operating costs of those facilities. See Note 12 for additional information. Regulation (PPL) WPD operates in an incentive-based regulatory structure under distribution licenses granted by Ofgem. Electricity distribution revenues are set by Ofgem for a given time period through price control reviews that are not directly based on cost recovery. The price control formula that governs WPD's allowed revenue is designed to provide economic incentives to minimize operating, capital and financing costs. As a result, WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP and does not record regulatory assets and liabilities. (PPL Electric, LG&E and KU) PPL Electric, LG&E and KU are cost-based rate-regulated utilities for which rates are set by regulators to enable PPL Electric, LG&E and KU to recover the costs of providing electric or gas service, as applicable, and to provide a reasonable return to shareholders. Base rates are generally established based on a future test period. As a result, the financial statements are subject to the accounting for certain types of regulation as prescribed by GAAP and reflect the effects of regulatory actions. Regulatory assets are recognized for the effect of transactions or events where future recovery of underlying costs is probable in regulated customer rates. The effect of such accounting is to defer certain or qualifying costs that would otherwise currently be charged to expense. Regulatory liabilities are recognized for amounts expected to be returned through future regulated customer rates. In certain cases, regulatory liabilities are recorded based on an understanding or agreement with the regulator that rates have been set to recover costs that are expected to be incurred in the future, and the regulated entity is accountable for any amounts charged pursuant to such rates and not yet expended for the intended purpose. The accounting for regulatory assets and regulatory liabilities is based on specific ratemaking decisions or precedent for each transaction or event as prescribed by the FERC or the applicable state regulatory commissions. See Note 6 for additional details regarding regulatory matters. Accounting Records The system of accounts for domestic regulated entities is maintained in accordance with the Uniform System of Accounts prescribed by the FERC and adopted by the applicable state regulatory commissions. (All Registrants) Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Loss Accruals Potential losses are accrued when (1) information is available that indicates it is "probable" that a loss has been incurred, given the likelihood of the uncertain future events and (2) the amount of the loss can be reasonably estimated. Accounting guidance defines "probable" as cases in which "the future event or events are likely to occur." The Registrants continuously assess potential loss contingencies for environmental remediation, litigation claims, regulatory penalties and other events. Loss accruals for environmental remediation are discounted when appropriate. The accrual of contingencies that might result in gains is not recorded, unless realization is assured. Earnings Per Share (PPL) EPS is computed using the two-class method, which is an earnings allocation method for computing EPS that treats a participating security as having rights to earnings that would otherwise have been available to common shareowners. Share-based payment awards that provide recipients a non-forfeitable right to dividends or dividend equivalents are considered participating securities. Price Risk Management (All Registrants) Interest rate contracts are used to hedge exposure to changes in the fair value of debt instruments and to hedge exposure to variability in expected cash flows associated with existing floating-rate debt instruments or forecasted fixed-rate issuances of debt. Foreign currency exchange contracts are used to hedge foreign currency exposures, primarily associated with PPL's investments in U.K. subsidiaries. Similar derivatives may receive different accounting treatment, depending on management's intended use and documentation. Certain contracts may not meet the definition of a derivative because they lack a notional amount or a net settlement provision. In cases where there is no net settlement provision, markets are periodically assessed to determine whether market mechanisms have evolved that would facilitate net settlement. Certain derivative contracts may be excluded from the requirements of derivative accounting treatment because NPNS has been elected. These contracts are accounted for using accrual accounting. Contracts that have been classified as derivative contracts are reflected on the balance sheets at fair value. The portion of derivative positions that deliver within a year are included in "Current Assets" and "Current Liabilities," while the portion of derivative positions that deliver beyond a year are recorded in "Other Noncurrent Assets" and "Deferred Credits and Other Noncurrent Liabilities." Cash inflows and outflows related to derivative instruments are included as a component of operating, investing or financing activities on the Statements of Cash Flows, depending on the classification of the hedged items. PPL and its subsidiaries have elected not to offset net derivative positions against the right to reclaim cash collateral (a receivable) or the obligation to return cash collateral (a payable) under master netting arrangements. (PPL) Processes exist that allow for subsequent review and validation of the contract information as it relates to interest rate and foreign currency derivatives. The accounting department provides the treasury department with guidelines on appropriate accounting classifications for various contract types and strategies. Examples of accounting guidelines provided to the treasury department staff include, but are not limited to: • Transactions to lock in an interest rate prior to a debt issuance can be designated as cash flow hedges, to the extent the forecasted debt issuances remain probable of occurring. • Cross-currency transactions to hedge interest and principal repayments can be designated as cash flow hedges. • Transactions to hedge fluctuations in the fair value of existing debt can be designated as fair value hedges. • Transactions to hedge the value of a net investment of foreign operations can be designated as net investment hedges. • Derivative transactions that do not qualify for cash flow or net investment hedge treatment are marked to fair value through earnings. These transactions generally include foreign currency forwards and options to hedge GBP-denominated earnings translation risk associated with PPL's U.K. subsidiaries that report their financial statements in GBP. As such, these transactions reduce earnings volatility due solely to changes in foreign currency exchange rates. (All Registrants) • Derivative transactions may be marked to fair value through regulatory assets/liabilities at PPL Electric, LG&E and KU if approved by the appropriate regulatory body. These transactions generally include the effect of interest rate swaps that are included in customer rates. (PPL and PPL Electric) To meet its obligation as a PLR to its customers, PPL Electric has entered into certain contracts that meet the definition of a derivative. However, NPNS has been elected for these contracts. See Notes 16 and 17 for additional information on derivatives. Revenue (PPL) Operating Revenues For the years ended December 31, the Statements of Income "Operating Revenues" line item contains revenue from the following: 2017 2016 2015 Domestic electric and gas revenues (a) $ 5,351 $ 5,297 $ 5,239 U.K. operating revenues (b) 2,091 2,207 2,410 Domestic - other 5 13 20 Total $ 7,447 $ 7,517 $ 7,669 (a) Represents revenues from cost-based rate-regulated generation, transmission and/or distribution in Pennsylvania, Kentucky, Virginia and Tennessee, including regulated wholesale revenue. (b) Primarily represents regulated electricity distribution revenues from the operation of WPD's distribution networks. Revenue Recognition (All Registrants) Operating revenues are primarily recorded based on energy deliveries through the end of the calendar month. Unbilled retail revenues result because customers' bills are rendered throughout the month, rather than bills being rendered at the end of the month. For LKE, LG&E and KU, unbilled revenues for a month are calculated by multiplying an estimate of unbilled kWh by the estimated average cents per kWh. Any difference between estimated and actual revenues is adjusted the following month when the previous unbilled estimate is reversed and actual billings occur. For PPL Electric, unbilled revenues for a month are calculated by multiplying the actual unbilled kWh by an average rate per customer class. (PPL) WPD is currently operating under the eight-year price control period of RIIO-ED1, which commenced for electric distribution companies on April 1, 2015. Ofgem has adopted a price control mechanism that establishes the amount of base demand revenue WPD can earn, subject to certain true-ups, and provides for an increase or reduction in revenues based on incentives or penalties for performance relative to pre-established targets. WPD's allowed revenue primarily includes base demand revenue (adjusted for inflation using RPI), performance incentive revenues/penalties and adjustments for over or under-recovery from prior periods. As the regulatory model is incentive based rather than a cost recovery model, WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. Therefore, the accounting treatment of adjustments to base demand revenue and/or allowed revenue is evaluated primarily based on revenue recognition accounting guidance. Unlike prior price control reviews, base demand revenue under RIIO-ED1 is adjusted during the price control period. The most significant of those adjustments are: • Inflation True-Up - The base demand revenue for the RIIO-ED1 period was set based on 2012/13 prices. Therefore an inflation factor as determined by forecasted RPI, provided by HM Treasury, is applied to base demand revenue. Forecasted RPI is trued up to actuals and affects future base demand revenue two regulatory years later. This revenue change is called the "TRU" adjustment. • Annual Iteration Process (AIP) - The RIIO-ED1 price control period also includes an AIP. This will allow future base demand revenues agreed with the regulator as part of the price control review, to be updated during the price control period for financial adjustments including tax, pensions, cost of debt, legacy price control adjustments from preceding price control periods and adjustments relating to actual and allowed total expenditure together with the Totex Incentive Mechanism (TIM). Under the TIM, WPD's DNOs are able to retain 70% of any amounts not spent against the RIIO-ED1 plan and bear 70% of any over-spends. The AIP calculates an incremental change to base demand revenue, known as the "MOD" adjustment. As both MOD and TRU are changes to future base demand revenues as determined by Ofgem, these adjustments are recognized as a component of revenues in future years in which service is provided and revenues are collected or returned to customers. In addition to base demand revenue, certain other items are added or subtracted to arrive at allowed revenue. The most significant of these are: • Incentives - Ofgem has established incentives to provide opportunities for DNO's to enhance overall returns by improving network efficiency, reliability and customer service. These incentives can result in an increase or reduction in revenues based on incentives or penalties for actual performance against pre-established targets based on past performance. The annual incentives and penalties are reflected in customers' rates on a two -year lag from the time they are earned and/or assessed. Incentive revenues and penalties are included in revenues when they are billed to customers. • Correction Factor - During the current price control period, WPD sets its tariffs to recover allowed revenue. However, in any fiscal period, WPD's revenue could be negatively affected if its tariffs and the volume delivered do not fully recover the revenue allowed for a particular period. Conversely, WPD could also over-recover revenue. Over and under-recoveries are subtracted from or added to allowed revenue in future years when they are billed to customers, known as the "Correction Factor" or "K-factor." Over and under-recovered amounts arising for the periods beginning with the 2014/15 regulatory year and refunded/recovered under RIIO-ED1 will be refunded/recovered on a two year lag (previously one year ). Therefore the 2014/15 over/under-recovery adjustment occurred in the 2016/17 regulatory year. Accounts Receivable (All Registrants) Accounts receivable are reported on the Balance Sheets at the gross outstanding amount adjusted for an allowance for doubtful accounts. Allowance for Doubtful Accounts Accounts receivable collectability is evaluated using a combination of factors, including past due status based on contractual terms, trends in write-offs and the age of the receivable. Specific events, such as bankruptcies, are also considered when applicable. Adjustments to the allowance for doubtful accounts are made when necessary based on the results of analysis, the aging of receivables and historical and industry trends. Accounts receivable are written off in the period in which the receivable is deemed uncollectible. The changes in the allowance for doubtful accounts were: Additions Balance at Beginning of Period Charged to Income Charged to Other Accounts Deductions (a) Balance at End of Period PPL 2017 $ 54 $ 28 $ (1 ) $ 30 $ 51 2016 41 44 — 31 54 2015 44 49 (2 ) 50 41 PPL Electric 2017 $ 28 $ 18 $ — $ 22 $ 24 2016 16 35 — 23 28 2015 17 39 — 40 16 Additions Balance at Beginning of Period Charged to Income Charged to Other Accounts Deductions (a) Balance at End of Period LKE 2017 $ 24 $ 8 $ (1 ) $ 6 $ 25 2016 23 8 — 7 24 2015 25 9 (2 ) 9 23 LG&E 2017 $ 2 $ 2 $ (1 ) $ 2 $ 1 2016 1 2 1 2 2 2015 2 2 — 3 1 KU 2017 $ 2 $ 4 $ (1 ) $ 4 $ 1 2016 2 4 — 4 2 2015 2 5 — 5 2 (a) Primarily related to uncollectible accounts written off. Cash (All Registrants) Cash Equivalents All highly liquid investments with original maturities of three months or less are considered to be cash equivalents. (PPL and PPL Electric) Restricted Cash and Cash Equivalents Bank deposits and other cash equivalents that are restricted by agreement or that have been clearly designated for a specific purpose are classified as restricted cash and cash equivalents. The change in restricted cash and cash equivalents is reported as an investing activity on the Statements of Cash Flows. On the Balance Sheets, the current portion of restricted cash and cash equivalents is included in "Other current assets," while the noncurrent portion is included in "Other noncurrent assets." At December 31, the balances of restricted cash and cash equivalents included the following: PPL PPL Electric 2017 2016 2017 2016 Low carbon network fund (a) $ 17 $ 17 $ — $ — Other 9 9 2 2 Total $ 26 $ 26 $ 2 $ 2 (a) Funds received by WPD, which are to be spent on approved initiatives to support a low carbon environment. (All Registrants) Fair Value Measurements The Registrants value certain financial and nonfinancial assets and liabilities at fair value. Generally, the most significant fair value measurements relate to price risk management assets and liabilities, investments in securities in defined benefit plans, and cash and cash equivalents. PPL and its subsidiaries use, as appropriate, a market approach (generally, data from market transactions), an income approach (generally, present value techniques and option-pricing models) and/or a cost approach (generally, replacement cost) to measure the fair value of an asset or liability. These valuation approaches incorporate inputs such as observable, independent market data and/or unobservable data that management believes are predicated on the assumptions market participants would use to price an asset or liability. These inputs may incorporate, as applicable, certain risks such as nonperformance risk, which includes credit risk. The Registrants classify fair value measurements within one of three levels in the fair value hierarchy. The level assigned to a fair value measurement is based on the lowest level input that is significant to the fair value measurement in its entirety. The three levels of the fair value hierarchy are as follows: • Level 1 - quoted prices (unadjusted) in active markets for identical assets or liabilities that are accessible at the measurement date. Active markets are those in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. • Level 2 - inputs other than quoted prices included within Level 1 that are either directly or indirectly observable for substantially the full term of the asset or liability. • Level 3 - unobservable inputs that management believes are predicated on the assumptions market participants would use to measure the asset or liability at fair value. Assessing the significance of a particular input requires judgment that considers factors specific to the asset or liability. As such, the Registrants' assessment of the significance of a particular input may affect how the assets and liabilities are classified within the fair value hierarchy. Investments (All Registrants) Generally, the original maturity date of an investment and management's intent and ability to sell an investment prior to its original maturity determine the classification of investments as either short-term or long-term. Investments that would otherwise be classified as short-term, but are restricted as to withdrawal or use for other than current operations or are clearly designated for expenditure in the acquisition or construction of noncurrent assets or for the liquidation of long-term debts, are classified as long-term. Short-term Investments Short-term investments generally include certain deposits as well as securities that are considered highly liquid or provide for periodic reset of interest rates. Investments with original maturities greater than three months and less than a year, as well as investments with original maturities of greater than a year that management has the ability and intent to sell within a year, are included in "Other current assets" on the Balance Sheets. (PPL, LKE, LG&E and KU) Cost Method Investment LG&E and KU each have an investment in OVEC, which is accounted for using the cost method. The investment is recorded in "Other noncurrent assets" on the PPL, LKE, LG&E and KU Balance Sheets. LG&E and KU and ten other electric utilities are equity owners of OVEC. OVEC's power is currently supplied to LG&E and KU and 11 other companies affiliated with the various owners. LG&E and KU own 5.63% and 2.5% of OVEC's common stock. Pursuant to a power purchase agreement, LG&E and KU are contractually entitled to their ownership percentage of OVEC's output, which is approximately 120 MW for LG&E and approximately 53 MW for KU. LG&E's and KU's combined investment in OVEC is not significant. The direct exposure to loss as a result of LG&E's and KU's involvement with OVEC is generally limited to the value of their investments; however, LG&E and KU are conditionally responsible for a pro-rata share of certain OVEC obligations, pursuant to their power purchase contract with OVEC. As part of PPL's acquisition of LKE, the value of the power purchase contract was recorded as an intangible asset with an offsetting regulatory liability, both of which are being amortized using the units-of-production method until March 2026. See Notes 6, 13 and 18 for additional discussion of the power purchase agreement. Long-Lived and Intangible Assets Property, Plant and Equipment (All Registrants) PP&E is recorded at original cost, unless impaired. PP&E acquired in business combinations is recorded at fair value at the time of acquisition. If impaired, the asset is written down to fair value at that time, which becomes the new cost basis of the asset. Original cost for constructed assets includes material, labor, contractor costs, certain overheads and financing costs, where applicable. The cost of repairs and minor replacements are charged to expense as incurred. The Registrants record costs associated with planned major maintenance projects in the period in which the costs are incurred. No costs associated with planned major maintenance projects are accrued to PP&E in advance of the period in which the work is performed. LG&E and KU accrue costs of removal net of estimated salvage value through depreciation, which is included in the calculation of customer rates over the assets' depreciable lives in accordance with regulatory practices. Cost of removal amounts accrued through depreciation rates are accumulated as a regulatory liability until the removal costs are incurred. For LKE, LG&E and KU, all ARO depreciation expenses are reclassified to a regulatory asset. See "Asset Retirement Obligations" below and Note 6 for additional information. PPL Electric records net costs of removal when incurred as a regulatory asset. The regulatory asset is subsequently amortized through depreciation over a five -year period, which is recoverable in customer rates in accordance with regulatory practices. AFUDC is capitalized at PPL Electric as part of the construction costs for cost-based rate-regulated projects for which a return on such costs is recovered after the project is placed in service. The debt component of AFUDC is credited to "Interest Expense" and the equity component is credited to "Other Income (Expense) - net" on the Statements of Income. LG&E and KU generally do not record AFUDC, except for certain instances in KU's FERC approved rates charged to its municipal customers, as a return is provided on construction work in progress. (PPL) PPL capitalizes interest costs as part of construction costs. Capitalized interest, including the debt component of AFUDC for PPL, was $11 million in 2017, 2016 and 2015. Depreciation (All Registrants) Depreciation is recorded over the estimated useful lives of property using various methods including the straight-line, composite and group methods. When a component of PP&E that was depreciated under the composite or group method is retired, the original cost is charged to accumulated depreciation. When all or a significant portion of an operating unit that was depreciated under the composite or group method is retired or sold, the property and the related accumulated depreciation account is reduced and any gain or loss is included in income, unless otherwise required by regulators. Following are the weighted-average annual rates of depreciation, for regulated utility plant, for the years ended December 31: 2017 2016 2015 PPL 2.65 % 2.73 % 2.57 % PPL Electric 2.86 % 2.63 % 2.46 % LKE 3.64 % 3.69 % 3.69 % LG&E 3.63 % 3.58 % 3.65 % KU 3.66 % 3.77 % 3.71 % (All Registrants) Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price paid over the fair value of the identifiable net assets acquired in a business combination. Other acquired intangible assets are initially measured based on their fair value. Intangibles that have finite useful lives are amortized over their useful lives based upon the pattern in which the economic benefits of the intangible assets are consumed or otherwise used. Costs incurred to obtain an initial license and renew or extend terms of licenses are capitalized as intangible assets. When determining the useful life of an intangible asset, including intangible assets that are renewed or extended, PPL and its subsidiaries consider: • the expected use of the asset; • the expected useful life of other assets to which the useful life of the intangible asset may relate; • legal, regulatory, or contractual provisions that may limit the useful life; • the company's historical experience as evidence of its ability to support renewal or extension; • the effects of obsolescence, demand, competition, and other economic factors; and, • the level of maintenance expenditures required to obtain the expected future cash flows from the asset. Asset Impairment (Excluding Investments) The Registrants review long-lived assets that are subject to depreciation or amortization, including finite-lived intangibles, for impairment when events or circumstances indicate carrying amounts may not be recoverable. A long-lived asset classified as held and used is impaired when the carrying amount of the asset exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. If impaired, the asset's carrying value is written down to its fair value. A long-lived asset classified as held for sale is impaired when the carrying amount of the asset (disposal group) exceeds its fair value less cost to sell. If impaired, the asset's (disposal group's) carrying value is written down to its fair value less cost to sell. PPL, LKE, LG&E and KU review goodwill for impairment at the reporting unit level annually or more frequently when events or circumstances indicate that the carrying amount of a reporting unit may be greater than the unit's fair value. Additionally, goodwill must be tested for impairment in circumstances when a portion of goodwill has been allocated to a business to be disposed. PPL's, LKE's, LG&E's and KU's reporting units are at the operating segment level. PPL, LKE, LG&E and KU may elect either to initially make a qualitative evaluation about the likelihood of an impairment of goodwill or to bypass the qualitative evaluation and test goodwill for impairment using a two-step quantitative test. If the qualitative evaluation (referred to as "step zero") is elected and the assessment results in a determination that it is not more likely than not that the fair value of a reporting unit is less than the carrying amount, the two-step quantitative impairment test is not necessary. However, the quantitative impairment test is required if management concludes it is more likely than not that the fair value of a reporting unit is less than the carrying amount based on the step zero assessment. If the carrying amount of the reporting unit, including goodwill, exceeds its fair value, the implied fair value of goodwill must be calculated in the same manner as goodwill in a business combination. The fair value of a reporting unit is allocated to all assets and liabilities of that unit as if the reporting unit had been acquired in a business combination. The excess of the fair value of the reporting unit over the amounts assigned to its assets and liabilities is the implied fair value of goodwill. If the implied fair value of goodwill is less than the carrying amount, goodwill is written down to its implied fair value. PPL (for its U.K. Regulated and Kentucky Regulated segments), and individually, LKE, LG&E and KU elected to perform the qualitative step zero evaluation of goodwill as of October 1, 2017. These evaluations considered the excess of fair value over the carrying value of each reporting unit that was calculated during step one of the quantitative impairment tests performed in the fourth quarter of 2015, and the relevant events and circumstances that occurred since those tests were performed including: • current year financial performance versus the prior year; • changes in planned capital expenditures; • the consistency of forecasted free cash flows; • earnings quality and sustainability; • changes in market participant discount rates; • changes in long-term growth rates • changes in PPL's market capitalization; and, • the overall economic and regulatory environments in which these regulated entities operate. Based on these evaluations, management concluded it was not more likely than not that the f

Segment and Related Information

Segment and Related Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment and Related Information	2. Segment and Related Information (PPL) PPL is organized into three segments: U.K. Regulated, Kentucky Regulated and Pennsylvania Regulated. PPL's segments are segmented by geographic location. The U.K. Regulated segment consists of PPL Global, which primarily includes WPD's regulated electricity distribution operations, the results of hedging the translation of WPD's earnings from GBP into U.S. dollars, and certain costs, such as U.S. income taxes, administrative costs, and certain acquisition-related financing costs. The Kentucky Regulated segment consists primarily of LKE's regulated electricity generation, transmission and distribution operations of LG&E and KU, as well as LG&E's regulated distribution and sale of natural gas. In addition, certain acquisition-related financing costs are allocated to the Kentucky Regulated segment. The Pennsylvania Regulated segment includes the regulated electricity transmission and distribution operations of PPL Electric. In addition, certain costs are allocated to the Pennsylvania Regulated segment. "Corporate and Other" primarily includes financing costs incurred at the corporate level that have not been allocated or assigned to the segments, as well as certain other unallocated costs, which is presented to reconcile segment information to PPL's consolidated results. On June 1, 2015, PPL completed the spinoff of PPL Energy Supply, which substantially represented PPL's Supply segment. As a result of this transaction, PPL no longer has a Supply segment and its results are presented in "Discontinued Operations". See Note 8 for additional information. Income Statement data for the segments and reconciliation to PPL's consolidated results for the years ended December 31 are as follows: 2017 2016 2015 Operating Revenues from external customers (a) U.K. Regulated $ 2,091 $ 2,207 $ 2,410 Kentucky Regulated 3,156 3,141 3,115 Pennsylvania Regulated 2,195 2,156 2,124 Corporate and Other 5 13 20 Total $ 7,447 $ 7,517 $ 7,669 Depreciation U.K. Regulated $ 230 $ 233 $ 242 Kentucky Regulated 439 404 382 Pennsylvania Regulated 309 253 214 Corporate and Other 30 36 45 Total $ 1,008 $ 926 $ 883 Amortization (b) U.K. Regulated $ 34 $ 16 $ 6 Kentucky Regulated 24 29 27 Pennsylvania Regulated 33 32 26 Corporate and Other 6 3 — Total $ 97 $ 80 $ 59 Unrealized (gains) losses on derivatives and other hedging activities (c) U.K. Regulated $ 166 $ 13 $ (88 ) Kentucky Regulated 6 6 11 Corporate and Other 6 — — Total $ 178 $ 19 $ (77 ) Interest Expense U.K. Regulated $ 397 $ 402 $ 417 Kentucky Regulated 261 260 232 Pennsylvania Regulated 142 129 130 Corporate and Other 101 97 92 Total $ 901 $ 888 $ 871 Income from Continuing Operations Before Income Taxes U.K. Regulated $ 804 $ 1,479 $ 1,249 Kentucky Regulated 645 640 547 Pennsylvania Regulated 575 550 416 Corporate and Other (d) (112 ) (119 ) (144 ) Total $ 1,912 $ 2,550 $ 2,068 Income Taxes (e) U.K. Regulated $ 152 $ 233 $ 128 Kentucky Regulated 359 242 221 Pennsylvania Regulated 216 212 164 Corporate and Other (d) 57 (39 ) (48 ) Total $ 784 $ 648 $ 465 Deferred income taxes and investment tax credits (f) U.K. Regulated $ 66 $ 31 $ 45 Kentucky Regulated 294 291 236 Pennsylvania Regulated 257 221 220 Corporate and Other (d) 90 17 (73 ) Total $ 707 $ 560 $ 428 2017 2016 2015 Net Income U.K. Regulated $ 652 $ 1,246 $ 1,121 Kentucky Regulated 286 398 326 Pennsylvania Regulated 359 338 252 Corporate and Other (d) (169 ) (80 ) (96 ) Discontinued Operations (g) — — (921 ) Total $ 1,128 $ 1,902 $ 682 (a) See Note 1 for additional information on Operating Revenues. (b) Represents non-cash expense items that include amortization of regulatory assets, debt discounts and premiums, debt issuance costs, emission allowances and RECs. (c) Includes unrealized gains and losses from economic activity. See Note 17 for additional information. (d) 2015 includes certain costs related to the spinoff of PPL Energy Supply, including deferred income tax expense, transition costs and separation benefits for PPL Services employees. See Note 8 for additional information. (e) Represents both current and deferred income taxes, including investment tax credits. See Note 5 for additional information on the impact of the TCJA in 2017. (f) Represents a non-cash expense item that is also included in "Income Taxes." (g) 2015 includes an $879 million loss on the spinoff of PPL Energy Supply and five months of Supply segment earnings. See Note 8 for additional information on these transactions. Cash Flow data for the segments and reconciliation to PPL's consolidated results for the years ended December 31 are as follows: 2017 2016 2015 Expenditures for long-lived assets U.K. Regulated $ 1,015 $ 1,031 $ 1,242 Kentucky Regulated 892 791 1,210 Pennsylvania Regulated 1,254 1,134 1,107 Corporate and Other 10 1 11 Total $ 3,171 $ 2,957 $ 3,570 The following provides Balance Sheet data for the segments and reconciliation to PPL's consolidated results as of: As of December 31, 2017 2016 Total Assets U.K. Regulated (a) $ 16,813 $ 14,537 Kentucky Regulated 14,468 14,037 Pennsylvania Regulated 10,082 9,426 Corporate and Other (b) 116 315 Total $ 41,479 $ 38,315 (a) Includes $12.5 billion and $10.8 billion of net PP&E as of December 31, 2017 and December 31, 2016. WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. (b) Primarily consists of unallocated items, including cash, PP&E and the elimination of inter-segment transactions. Geographic data for the years ended December 31 are as follows: 2017 2016 2015 Revenues from external customers U.K. $ 2,091 $ 2,207 $ 2,410 U.S. 5,356 5,310 5,259 Total $ 7,447 $ 7,517 $ 7,669 As of December 31, 2017 2016 Long-Lived Assets U.K. $ 12,851 $ 11,177 U.S. 20,936 19,595 Total $ 33,787 $ 30,772 (PPL Electric, LKE, LG&E and KU) PPL Electric has two operating segments that are aggregated into a single reportable segment. LKE, LG&E and KU are individually single operating and reportable segments.

Preferred Securities

Preferred Securities	12 Months Ended
	Dec. 31, 2017
Preferred Securities [Line Items]
Preferred Securities	3. Preferred Securities (PPL) PPL is authorized to issue up to 10 million shares of preferred stock. No PPL preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (PPL Electric) PPL Electric is authorized to issue up to 20,629,936 shares of preferred stock. No PPL Electric preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (LG&E) LG&E is authorized to issue up to 1,720,000 shares of preferred stock at a $25 par value and 6,750,000 shares of preferred stock without par value. LG&E had no preferred stock issued or outstanding in 2017 , 2016 or 2015 . (KU) KU is authorized to issue up to 5,300,000 shares of preferred stock and 2,000,000 shares of preference stock without par value. KU had no preferred or preference stock issued or outstanding in 2017 , 2016 or 2015 .
PPL Electric Utilities Corp [Member]
Preferred Securities [Line Items]
Preferred Securities	3. Preferred Securities (PPL) PPL is authorized to issue up to 10 million shares of preferred stock. No PPL preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (PPL Electric) PPL Electric is authorized to issue up to 20,629,936 shares of preferred stock. No PPL Electric preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (LG&E) LG&E is authorized to issue up to 1,720,000 shares of preferred stock at a $25 par value and 6,750,000 shares of preferred stock without par value. LG&E had no preferred stock issued or outstanding in 2017 , 2016 or 2015 . (KU) KU is authorized to issue up to 5,300,000 shares of preferred stock and 2,000,000 shares of preference stock without par value. KU had no preferred or preference stock issued or outstanding in 2017 , 2016 or 2015 .
Louisville Gas And Electric Co [Member]
Preferred Securities [Line Items]
Preferred Securities	3. Preferred Securities (PPL) PPL is authorized to issue up to 10 million shares of preferred stock. No PPL preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (PPL Electric) PPL Electric is authorized to issue up to 20,629,936 shares of preferred stock. No PPL Electric preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (LG&E) LG&E is authorized to issue up to 1,720,000 shares of preferred stock at a $25 par value and 6,750,000 shares of preferred stock without par value. LG&E had no preferred stock issued or outstanding in 2017 , 2016 or 2015 . (KU) KU is authorized to issue up to 5,300,000 shares of preferred stock and 2,000,000 shares of preference stock without par value. KU had no preferred or preference stock issued or outstanding in 2017 , 2016 or 2015 .
Kentucky Utilities Co [Member]
Preferred Securities [Line Items]
Preferred Securities	3. Preferred Securities (PPL) PPL is authorized to issue up to 10 million shares of preferred stock. No PPL preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (PPL Electric) PPL Electric is authorized to issue up to 20,629,936 shares of preferred stock. No PPL Electric preferred stock was issued or outstanding in 2017 , 2016 or 2015 . (LG&E) LG&E is authorized to issue up to 1,720,000 shares of preferred stock at a $25 par value and 6,750,000 shares of preferred stock without par value. LG&E had no preferred stock issued or outstanding in 2017 , 2016 or 2015 . (KU) KU is authorized to issue up to 5,300,000 shares of preferred stock and 2,000,000 shares of preference stock without par value. KU had no preferred or preference stock issued or outstanding in 2017 , 2016 or 2015 .

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	4. Earnings Per Share (PPL) Basic EPS is computed by dividing income available to PPL common shareowners by the weighted-average number of common shares outstanding during the applicable period. Diluted EPS is computed by dividing income available to PPL common shareowners by the weighted-average number of common shares outstanding, increased by incremental shares that would be outstanding if potentially dilutive non-participating securities were converted to common shares as calculated using the Treasury Stock Method. Incremental non-participating securities that have a dilutive impact are detailed in the table below. Reconciliations of the amounts of income and shares of PPL common stock (in thousands) for the periods ended December 31, used in the EPS calculation are: 2017 2016 2015 Income (Numerator) Income from continuing operations after income taxes $ 1,128 $ 1,902 $ 1,603 Less amounts allocated to participating securities 2 6 6 Income from continuing operations after income taxes available to PPL common shareowners - Basic and Diluted $ 1,126 $ 1,896 $ 1,597 Income (loss) from discontinued operations (net of income taxes) available to PPL common shareowners - Basic and Diluted $ — $ — $ (921 ) Net income $ 1,128 $ 1,902 $ 682 Less amounts allocated to participating securities 2 6 2 Net income available to PPL common shareowners - Basic and Diluted $ 1,126 $ 1,896 $ 680 2017 2016 2015 Shares of Common Stock (Denominator) Weighted-average shares - Basic EPS 685,240 677,592 669,814 Add incremental non-participating securities: Share-based payment awards (a) 2,094 2,854 2,772 Weighted-average shares - Diluted EPS 687,334 680,446 672,586 Basic EPS Available to PPL common shareowners: Income from continuing operations after income taxes $ 1.64 $ 2.80 $ 2.38 Income (loss) from discontinued operations (net of income taxes) — — (1.37 ) Net Income $ 1.64 $ 2.80 $ 1.01 Diluted EPS Available to PPL common shareowners: Income from continuing operations after income taxes $ 1.64 $ 2.79 $ 2.37 Income (loss) from discontinued operations (net of income taxes) — — (1.36 ) Net Income $ 1.64 $ 2.79 $ 1.01 (a) The Treasury Stock Method was applied to non-participating share-based payment awards. For the year ended December 31, PPL issued common stock related to stock-based compensation plans and DRIP as follows (in thousands): 2017 Stock-based compensation plans (a) 1,748 DRIP 1,552 (a) Includes stock options exercised, vesting of performance units, vesting of restricted stock and restricted stock units and conversion of stock units granted to directors. See Note 7 for additional information on common stock issued under ATM Program. For the years ended December 31, the following shares (in thousands) were excluded from the computations of diluted EPS because the effect would have been antidilutive: 2017 2016 2015 Stock options 696 696 1,087 Performance units — 176 36

Income and Other Taxes

Income and Other Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income and Other Taxes	5. Income and Other Taxes (All Registrants) Tax Cuts and Jobs Act (TCJA) On December 22, 2017, President Trump signed into law the TCJA. Substantially all of the provisions of the TCJA are effective for taxable years beginning after December 31, 2017. The TCJA includes significant changes to the taxation of corporations, including provisions specifically applicable to regulated public utilities. The more significant changes that impact the Registrants are: • The reduction in the U.S. federal corporate income tax rate from a top marginal rate of 35% to a flat rate of 21%, effective January 1, 2018; • The exclusion from U.S. federal taxable income of dividends from foreign subsidiaries and the associated "transition tax;" • Limitations on the tax deductibility of interest expense, with an exception to these limitations for regulated public utilities; • Full current year expensing of capital expenditures with an exception for regulated public utilities that qualify for the exception to the interest expense limitation; and • The continuation of certain rate normalization requirements for accelerated depreciation benefits. For non-regulated businesses, the TCJA generally provides for full expensing of property acquired after September 27, 2017. Under GAAP, the tax effect of changes in tax laws must be recognized in the period in which the law is enacted, or December 2017 for TCJA. The changes enacted by the TCJA were recorded as an adjustment to the Registrants' deferred tax provision, and have been reflected in "Income Taxes" on the Statement of Income for the year ended December 31, 2017 as follows: PPL PPL Electric LKE LG&E KU Income tax expense (benefit) $ 321 $ (13 ) $ 112 $ — $ — The components of these adjustments are discussed below: Reduction of U.S. Federal Corporate Income Tax Rate GAAP requires deferred tax assets and liabilities to be measured at the enacted tax rate expected to apply when temporary differences are to be realized or settled. Thus, at the date of enactment, the Registrants' deferred taxes were remeasured based upon the new U.S. federal corporate income tax rate of 21%. For PPL’s regulated entities, the changes in deferred taxes were, in large part, recorded as an offset to either a regulatory asset or regulatory liability and will be reflected in future rates charged to customers. The rate reduction on non-regulated deferred tax assets and liabilities were recorded as an adjustment to the Registrants' deferred tax provision, and have been reflected in "Income Taxes" on the Statement of Income for the year ended December 31, 2017 as follows: PPL PPL Electric LKE LG&E KU Income tax expense (benefit) $ 220 $ (13 ) $ 112 $ — $ — As indicated in Note 1 - "Summary of Significant Accounting Policies - Income Taxes", PPL’s U.S. regulated operations' accounting for income taxes are impacted by rate regulation. Therefore, reductions in accumulated deferred income tax balances due to the reduction in the U.S. federal corporate income tax rate to 21% under the provisions of the TCJA may result in amounts previously collected from utility customers for these deferred taxes to be refundable to such customers over a period of time. The TCJA includes provisions that stipulate how these excess deferred taxes are to be passed back to customers for certain accelerated tax depreciation benefits. Potential refunds of other deferred taxes will be determined by the Registrants’ regulators. The Balance Sheets at December 31, 2017 reflect the increase to the Registrants' net regulatory liabilities as a result of the TCJA as follows: PPL PPL Electric LKE LG&E KU Net Increase in Regulatory Liabilities $ 2,185 $ 1,019 $ 1,166 $ 532 $ 634 Prior to the TCJA, PPL Electric had recorded a net regulatory asset related to taxes recoverable on certain property related deferred taxes, the tax benefit of which was received by the customer. The net regulatory asset represents the future taxes owed in excess of taxes paid by the customer to date, with an additional tax gross-up. As a result of the U.S. federal corporate income tax rate reduction enacted by the TCJA, the future taxes expected to be due are now less than taxes funded through rates, resulting in a net regulatory liability. Transition Tax The TCJA included a conversion from a worldwide tax system to a territorial tax system, effective January 1, 2018. In the transition to the territorial regime, a one-time transition tax was imposed on PPL’s unrepatriated accumulated foreign earnings in 2017. These earnings were treated as a taxable deemed dividend to PPL of approximately $462 million . As the PPL consolidated U.S. group had a taxable loss for 2017, inclusive of the taxable deemed dividend, the foreign tax credits associated with the deemed dividend were recorded as a deferred tax asset. However, it is expected that under the TCJA, the current and prior year foreign tax credit carryforwards will not be fully realizable. As a result, the net deferred income tax expense impact of the deemed repatriation was $101 million and was recorded in "Income Taxes" on the PPL Statement of Income for the year ended December 31, 2017 and "Deferred tax liabilities" on the PPL Balance Sheet at December 31, 2017. SEC Guidance on Accounting for TCJA On December 22, 2017, the SEC issued guidance for accounting for income taxes in the event that information is not available or is incomplete for purposes of reflecting the impact of the TCJA. The SEC guidance provides a period of up to one year (the measurement period) to complete the analysis and accounting to properly reflect the TCJA. The SEC guidance provides a three-step process that companies should apply to each reporting period within the measurement period: 1. A company should record the effects of the TCJA for which the accounting is complete. 2. A company should report provisional amounts (or adjustments to provisional amounts) for the effects of the TCJA for which the accounting is not complete, but for which a reasonable estimate can be determined. Provisional amounts and any related adjustments to such provisional amounts should be recorded to income tax expense through continuing operations in the period they are identified. 3. A company should continue to apply GAAP based on the tax law in effect just prior to enactment of TCJA if a reasonable estimate of the specific effect of the TCJA cannot be made. The measurement period ends at the earlier of the time the company finalizes its accounting for the impact of the TCJA or one year. The Registrants have completed or made reasonable estimates of the effects of the TCJA and reflected these amounts in their December 31, 2017 financial statements. The Registrants continue to evaluate the application of the TCJA and have made certain assumptions concerning the application of various components of the law in the calculation of 2017 income tax expense. The current and deferred components of the income tax expense calculations that the Registrants consider provisional within the meaning of the SEC guidance due to uncertainty either with respect to the technical application of the law or the quantification of the impact of the law include (but are not limited to): tax depreciation, deductible executive compensation, and the accumulated foreign earnings used to calculate the deemed dividend included in PPL’s taxable income in 2017 along with the impact of associated foreign tax credits and related valuation allowances. The Registrants believe that classification of these items as provisional is appropriate. The Registrants have accounted for these items based on their interpretation of the TCJA. Further interpretive guidance on the TCJA from the IRS, Treasury, the Joint Committee on Taxation through its “Blue Book” or from Congress in the form of Technical Corrections may differ from the Registrants' interpretation of the TCJA. (PPL) "Income from Continuing Operations Before Income Taxes" included the following: 2017 2016 2015 Domestic income $ 874 $ 1,463 $ 968 Foreign income 1,038 1,087 1,100 Total $ 1,912 $ 2,550 $ 2,068 Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for accounting purposes and their basis for income tax purposes and the tax effects of net operating loss and tax credit carryforwards. The provision for PPL's deferred income taxes for regulated assets and liabilities is based upon the ratemaking principles of the applicable jurisdiction. See Notes 1 and 6 for additional information. Net deferred tax assets have been recognized based on management's estimates of future taxable income for the U.S. and the U.K. Significant components of PPL's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Deferred investment tax credits $ 33 $ 51 Regulatory liabilities 62 94 Income taxes due to customer (b) 499 — Accrued pension costs 159 250 Federal loss carryforwards 356 565 State loss carryforwards 409 326 Federal and state tax credit carryforwards 455 256 Foreign capital loss carryforwards 329 302 Foreign loss carryforwards 2 3 Foreign - pensions (32 ) 41 Foreign - regulatory obligations 2 6 Foreign - other 7 5 Contributions in aid of construction 134 141 Domestic - other 104 188 Unrealized losses on qualifying derivatives 10 20 Valuation allowances (838 ) (593 ) Total deferred tax assets 1,691 1,655 Deferred Tax Liabilities Domestic plant - net (b) 3,168 4,325 Taxes recoverable through future rates (b) — 170 Regulatory assets 211 343 Reacquired debt costs 15 25 Foreign plant - net 726 640 Domestic - other 9 14 Total deferred tax liabilities 4,129 5,517 Net deferred tax liability $ 2,438 $ 3,862 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal corporate income tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset. State deferred taxes are determined on a by entity, by jurisdiction basis. As a result, $24 million and $27 million of net deferred tax assets are shown as "Other noncurrent assets" on the Balance Sheets for 2017 and 2016 . At December 31, 2017 , PPL had the following loss and tax credit carryforwards, related deferred tax assets and valuation allowances recorded against the deferred tax assets. Gross Deferred Tax Asset Valuation Allowance Expiration Loss carryforwards Federal net operating losses (a) $ 1,662 $ 349 $ — 2029-2037 Federal charitable contributions (a) 36 7 — 2020-2022 State net operating losses (a) 5,512 407 (348 ) 2018-2037 State charitable contributions (a) 26 2 — 2018-2022 Foreign net operating losses 10 2 — Indefinite Foreign capital losses 1,938 329 (329 ) Indefinite Credit carryforwards Federal investment tax credit 133 — 2025-2036 Federal alternative minimum tax credit (b) 30 — Indefinite Federal foreign tax credits (c) 267 (148 ) 2024-2027 Federal - other 24 (8 ) 2019-2037 State - other 1 — Indefinite (a) Due to the enactment of the TCJA, deferred tax assets are reflected at the new U.S. federal corporate income tax rate of 21%. (b) The TCJA repealed the corporate alternative minimum tax (AMT) for tax years beginning after December 31, 2017. The existing indefinite carryforward period for AMT credits was retained. (c) Includes $62 million of foreign tax credits carried forward from 2016 and $205 million of additional foreign tax credits in 2017 related to the taxable deemed dividend associated with the TCJA. Valuation allowances have been established for the amount that, more likely than not, will not be realized. The changes in deferred tax valuation allowances were as follows: Additions Balance at Beginning of Period Charged to Income Charged to Other Accounts Deductions Balance at End of Period 2017 $ 593 $ 256 (a) $ — $ 11 $ 838 2016 662 17 2 88 (b) 593 2015 622 24 77 (c) 61 (b) 662 (a) Increase in valuation allowance of approximately $145 million related to expected future utilization of both 2017 foreign tax credits and pre-2017 foreign tax credits carried forward. For additional information, see the "Reconciliation of Income Tax Expense" and associated notes below. In addition, the reduction of the U.S. federal corporate income tax rate enacted by the TCJA in 2017 resulted in a $62 million increase in federal deferred tax assets and a corresponding valuation allowance related to the federal tax benefits of state net operating losses. (b) The reductions of the U.K. statutory income tax rates in 2016 and 2015 resulted in $19 million and $44 million in reductions in the deferred tax assets and corresponding valuation allowances. See "Reconciliation of Income Tax Expense" below for more information on the impact of the U.K. Finance Acts 2016 and 2015. In addition, the deferred tax assets and corresponding valuation allowances were reduced in 2016 by approximately $65 million due to the effect of foreign currency exchange rates. (c) Valuation allowance related to the deferred tax assets previously reflected on the PPL Energy Supply Segment. The deferred tax assets and related valuation allowance remained with PPL after the spinoff. PPL Global does not record U.S. income taxes on the unremitted earnings of WPD, as management has determined that such earnings are indefinitely reinvested. Current year distributions from WPD to the U.S. are sourced from a portion of the current year’s earnings of the WPD group. As noted above, the TCJA includes a conversion from a worldwide tax system to a territorial tax system, effective January 1, 2018. In the transition to the territorial regime, a one-time transition tax was imposed on PPL’s unrepatriated accumulated foreign earnings in 2017. These earnings were treated as a taxable deemed dividend from the U.K. The total amount of the taxable deemed dividend was approximately $462 million , including $205 million of foreign tax credits. The U.S. tax consequences of the deemed dividend have been recorded in PPL’s 2017 tax provision and are explained below. Despite this 2017 deemed dividend, there have been no material changes to the facts underlying PPL’s assertion that historically reinvested earnings of WPD as well as some portion of current year earnings will continue to be indefinitely reinvested. WPD's long-term working capital forecasts and capital expenditure projections for the foreseeable future require reinvestment of WPD's undistributed earnings. Additionally, U.S. long-term working capital forecasts and capital expenditure projections for the foreseeable future do not require or contemplate annual distributions from WPD in excess of some portion of WPD's future annual earnings. The cumulative undistributed earnings are included in "Earnings reinvested" on the Balance Sheets. The amount considered indefinitely reinvested at December 31, 2017 was $6.0 billion . It is not practicable to estimate the amount of additional taxes that could be payable on these foreign earnings in the event of repatriation to the U.S. Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows: 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ 6 $ (14 ) $ (26 ) Current - State 25 21 25 Current - Foreign 45 80 89 Total Current Expense 76 87 88 Deferred - Federal (a) 532 385 699 Deferred - State 88 89 68 Deferred - Foreign 133 86 41 Total Deferred Expense, excluding operating loss carryforwards 753 560 808 2017 2016 2015 Income Tax Expense (Benefit) Amortization of investment tax credit (3 ) (3 ) (4 ) Tax expense (benefit) of operating loss carryforwards Deferred - Federal (b) (16 ) 25 (396 ) Deferred - State (26 ) (21 ) (31 ) Total Tax Expense (Benefit) of Operating Loss Carryforwards (42 ) 4 (427 ) Total income taxes from continuing operations $ 784 $ 648 $ 465 Total income tax expense - Federal $ 519 $ 393 $ 273 Total income tax expense - State 87 89 62 Total income tax expense - Foreign 178 166 130 Total income taxes from continuing operations $ 784 $ 648 $ 465 (a) Due to the enactment of the TCJA in 2017, PPL recorded the following: • $220 million of deferred income tax expense related to the impact of the U.S. federal corporate income tax rate reduction from 35% to 21% on deferred tax assets and liabilities; • $162 million of deferred tax expense related to the utilization of current year losses resulting from the taxable deemed dividend; partially offset by, • $60 million of deferred tax benefits related to the $205 million of 2017 foreign tax credits partially offset by $145 million of valuation allowances. (b) Increase in federal loss carryforwards for 2015 primarily relates to the extension of bonus depreciation and the impact of bonus depreciation related to provision to return adjustments. In the table above, the following income tax expense (benefit) are excluded from income taxes from continuing operations: 2017 2016 2015 Discontinued operations - PPL Energy Supply Segment $ — $ — $ (30 ) Stock-based compensation recorded to Earnings Reinvested — (7 ) — Other comprehensive income (34 ) (6 ) (2 ) Valuation allowance on state deferred taxes recorded to other comprehensive income (1 ) 1 (4 ) Total $ (35 ) $ (12 ) $ (36 ) 2017 2016 2015 Reconciliation of Income Tax Expense Federal income tax on Income from Continuing Operations Before Income Taxes at statutory tax rate - 35% $ 669 $ 893 $ 724 Increase (decrease) due to: State income taxes, net of federal income tax benefit 46 46 31 Valuation allowance adjustments (a) 36 16 24 Impact of lower U.K. income tax rates (b) (176 ) (177 ) (176 ) U.S. income tax on foreign earnings - net of foreign tax credit (c) 47 (42 ) 8 Federal and state tax reserves adjustments (d) — — (22 ) Foreign income return adjustments (8 ) 2 — Impact of the U.K. Finance Acts on deferred tax balances (b) (16 ) (49 ) (91 ) Depreciation not normalized (10 ) (10 ) (5 ) Interest benefit on U.K. financing entities (16 ) (17 ) (20 ) Stock-based compensation (e) (3 ) (10 ) — Deferred tax impact of U.S. tax reform (f) 220 — — Other (5 ) (4 ) (8 ) Total increase (decrease) 115 (245 ) (259 ) Total income taxes from continuing operations $ 784 $ 648 $ 465 Effective income tax rate 41.0 % 25.4 % 22.5 % (a) During 2017, PPL recorded an increase in valuation allowances of $23 million primarily related to foreign tax credits recorded in 2016. The future utilization of these credits is expected to be lower as a result of the TCJA. During 2017 and 2016, PPL recorded deferred income tax expense of $16 million and $13 million for valuation allowances primarily related to increased Pennsylvania net operating loss carryforwards expected to be unutilized. During 2015, PPL recorded $24 million of deferred income tax expense related to deferred tax valuation allowances. PPL recorded state deferred income tax expense of $12 million primarily related to increased Pennsylvania net operating loss carryforwards expected to be unutilized and $12 million of federal deferred income tax expense primarily related to federal tax credit carryforwards that are expected to expire as a result of lower future taxable earnings due to the extension of bonus depreciation. (b) The U.K. Finance Act 2016, enacted in September 2016, reduced the U.K. statutory income tax rate effective April 1, 2020 from 18% to 17%. As a result, PPL reduced its net deferred tax liabilities and recognized a $42 million deferred income tax benefit during 2016. The U.K. Finance Act 2015, enacted in November 2015, reduced the U.K. statutory income tax rate from 20% to 19% effective April 1, 2017 and from 19% to 18% effective April 1, 2020. As a result, PPL reduced its net deferred tax liabilities and recognized a $90 million deferred income tax benefit during 2015, related to both rate decreases. (c) During 2017, PPL recorded a federal income tax benefit of $35 million primarily attributable to U.K. pension contributions. During 2017, PPL recorded deferred income tax expense of $83 million primarily related to enactment of the TCJA. The enacted tax law included a conversion from a worldwide tax system to a territorial tax system, effective January 1, 2018. In the transition to the territorial regime, a one-time transition tax was imposed on PPL’s unrepatriated accumulated foreign earnings in 2017. These earnings were treated as a taxable deemed dividend to PPL of approximately $462 million , including $205 million of foreign tax credits. As the PPL consolidated U.S. group had a taxable loss for 2017, inclusive of the taxable deemed dividend, these credits were recorded as a deferred tax asset. However, it is expected that under the TCJA, only $83 million of the $205 million of foreign tax credits will be realized in the carry forward period. Accordingly, a valuation allowance on the current year foreign tax credits in the amount of $122 million has been recorded to reflect the reduction in the future utilization of the credits. The foreign tax credits associated with the deemed repatriation result in a gross carryforward and corresponding deferred tax asset of $205 million offset by a valuation allowance of $122 million . During 2016, PPL recorded lower income taxes primarily attributable to foreign tax credit carryforwards, arising from a decision to amend prior year tax returns to claim foreign tax credits rather than deduct foreign taxes. This decision was prompted by changes to the Company's most recent business plan. (d) During 2015, PPL recorded a $9 million income tax benefit related to a planned amendment of a prior period tax return and a $12 million income tax benefit related to the settlement of the IRS audit for the tax years 1998-2011. (e) During 2016, PPL recorded lower income tax expense related to the application of new stock-based compensation accounting guidance. See Note 1 for additional information. (f) During 2017, PPL recorded deferred income tax expense related to the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. 2017 2016 2015 Taxes, other than income State gross receipts (a) $ 102 $ 100 $ 89 State capital stock (6 ) — — Foreign property 127 135 148 Domestic Other 69 66 62 Total $ 292 $ 301 $ 299 (a) In 2015, the settlement of a 2011 gross receipts tax audit resulted in the reversal of $17 million of previously recognized reserves. (PPL Electric) The provision for PPL Electric's deferred income taxes for regulated assets and liabilities is based upon the ratemaking principles reflected in rates established by the PUC and the FERC. The difference in the provision for deferred income taxes for regulated assets and liabilities and the amount that otherwise would be recorded under GAAP is deferred and included in "Regulatory assets" or "Regulatory liabilities" on the Balance Sheets. Significant components of PPL Electric's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Accrued pension costs $ 63 $ 107 Contributions in aid of construction 117 112 Regulatory liabilities 25 34 Income taxes due to customers (b) 193 — State loss carryforwards 19 22 Federal loss carryforwards 91 147 Other 45 81 Total deferred tax assets 553 503 Deferred Tax Liabilities Electric utility plant - net (b) 1,544 2,001 Taxes recoverable through future rates (b) — 141 Reacquired debt costs 8 15 Regulatory assets 150 240 Other 5 5 Total deferred tax liabilities 1,707 2,402 Net deferred tax liability $ 1,154 $ 1,899 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset. At December 31, 2017 , PPL Electric had the following loss carryforwards and related deferred tax assets: Gross Deferred Tax Asset Expiration Loss carryforwards (a) Federal net operating losses $ 426 $ 89 2031-2037 Federal charitable contributions 8 2 2020-2022 State net operating losses 233 18 2030-2032 State charitable contributions 13 1 2018-2022 (a) Due to the enactment of the TCJA, deferred tax assets are reflected at the new U.S. federal corporate income tax rate of 21%. Credit carryforwards were insignificant at December 31, 2017 . Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows. 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ (65 ) $ (29 ) $ (80 ) Current - State 20 19 23 Total Current Expense (Benefit) (45 ) (10 ) (57 ) Deferred - Federal (a) 234 193 287 Deferred - State 29 29 12 Total Deferred Expense, excluding operating loss carryforwards 263 222 299 2017 2016 2015 Amortization of investment tax credit — — — Tax expense (benefit) of operating loss carryforwards Deferred - Federal (5 ) — (75 ) Deferred - State — — (3 ) Total Tax Expense (Benefit) of Operating Loss Carryforwards (5 ) — (78 ) Total income tax expense $ 213 $ 212 $ 164 Total income tax expense - Federal $ 164 $ 164 $ 132 Total income tax expense - State 49 48 32 Total income tax expense $ 213 $ 212 $ 164 (a) Due to the enactment of the TCJA in 2017, PPL Electric recorded a $13 million deferred tax benefit related to the impact of the U.S. federal corporate income tax rate reduction from 35% to 21% on deferred tax assets and liabilities. 2017 2016 2015 Reconciliation of Income Taxes Federal income tax on Income Before Income Taxes at statutory tax rate - 35% $ 201 $ 193 $ 146 Increase (decrease) due to: State income taxes, net of federal income tax benefit 36 36 25 Depreciation not normalized (8 ) (8 ) (4 ) Stock-based compensation (a) (2 ) (6 ) — Deferred tax impact of U.S. tax reform (b) (13 ) — — Other (1 ) (3 ) (3 ) Total increase (decrease) 12 19 18 Total income tax expense $ 213 $ 212 $ 164 Effective income tax rate 37.0 % 38.4 % 39.4 % (a) During 2016, PPL Electric recorded lower income tax expense related to the application of new stock-based compensation accounting guidance. See Note 1 for additional information. (b) During 2017, PPL Electric recorded a deferred tax benefit related to the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. 2017 2016 2015 Taxes, other than income State gross receipts (a) $ 102 $ 100 $ 89 Property and other 5 5 5 Total $ 107 $ 105 $ 94 (a) In 2015, the settlement of a 2011 gross receipts tax audit resulted in the reversal of $17 million of previously recognized reserves. (LKE) The provision for LKE's deferred income taxes for regulated assets and liabilities is based upon the ratemaking principles reflected in rates established by the KPSC, VSCC and the FERC. The difference in the provision for deferred income taxes for regulated assets and liabilities and the amount that otherwise would be recorded under GAAP is deferred and included in "Regulatory assets" or "Regulatory liabilities" on the Balance Sheets. Significant components of LKE's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Federal loss carryforwards $ 150 $ 248 State loss carryforwards 41 35 Federal tax credit carryforwards 181 186 Contributions in aid of construction 17 29 Regulatory liabilities 37 60 Accrued pension costs 29 58 Income taxes due to customers (b) 305 15 Deferred investment tax credits 33 51 Derivative liability 7 12 Other 26 49 Valuation allowances (8 ) (11 ) Total deferred tax assets 818 732 Deferred Tax Liabilities Plant - net (b) 1,615 2,352 Regulatory assets 61 102 Other 8 13 Total deferred tax liabilities 1,684 2,467 Net deferred tax liability $ 866 $ 1,735 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset. At December 31, 2017 , LKE had the following loss and tax credit carryforwards, related deferred tax assets, and valuation allowances recorded against the deferred tax assets. Gross Deferred Tax Asset Valuation Allowance Expiration Loss carryforwards (a) Federal net operating losses $ 713 $ 150 $ — 2028-2037 Federal charitable contributions 14 3 — 2020-2022 State net operating losses 874 41 — 2028-2037 Credit carryforwards Federal investment tax credit 133 — 2025-2036 Federal alternative minimum tax credit (b) 27 — Indefinite Federal - other 21 (8 ) 2019-2037 State - other 1 — Indefinite (a) Due to the enactment of the TCJA, deferred tax assets are reflected at the new U.S. federal corporate income tax rate of 21%. (b) The TCJA repealed the corporate alternative minimum tax (AMT) for tax years beginning after December 31, 2017. The existing indefinite carryforward period for AMT credits was retained. Changes in deferred tax valuation allowances were: Balance at Beginning of Period Additions Deductions Balance at End of Period 2017 $ 11 $ 4 (a) $ 7 (b) $ 8 2016 12 — 1 (b) 11 2015 — 12 (c) — 12 (a) Federal tax credits expiring in 2021 that are more likely than not to expire before being utilized. (b) Federal tax credit expiring. (c) Federal tax credits expiring in 2016 through 2020 that are more likely than not to expire before being utilized. Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ 74 $ (36 ) $ 2 Current - State 6 1 1 Total Current Expense (Benefit) 80 (35 ) 3 Deferred - Federal (a) 268 248 405 Deferred - State 32 38 32 Total Deferred Expense, excluding benefits of operating loss carryforwards 300 286 437 Amortization of investment tax credit - Federal (3 ) (3 ) (3 ) Tax benefit of operating loss carryforwards Deferred - Federal (2 ) 10 (198 ) Deferred - State — (1 ) — Total Tax Expense (Benefit) of Operating Loss Carryforwards (2 ) 9 (198 ) Total income tax expense from continuing operations (b) $ 375 $ 257 $ 239 Total income tax expense - Federal $ 337 $ 219 $ 206 Total income tax expense - State 38 38 33 Total income tax expense from continuing operations (b) $ 375 $ 257 $ 239 (a) Due to the enactment of the TCJA in 2017, LKE recorded $112 million of deferred income tax expense, of which $108 million related to the impact of the U.S. federal corporate income tax rate reduction from 35% to 21% on deferred tax assets and liabilities and $4 million related to valuation allowances on tax credits expiring in 2021. (b) Excludes deferred federal and state tax expense (benefit) recorded to OCI of $(10) million in 2017 , $(16) million in 2016 and less than $(1) million in 2015 . 2017 2016 2015 Reconciliation of Income Taxes Federal income tax on Income Before Income Taxes at statutory tax rate - 35% $ 242 $ 240 $ 211 Increase (decrease) due to: State income taxes, net of federal income tax benefit 25 25 22 Amortization of investment tax credit (3 ) (3 ) (3 ) Valuation allowance adjustment (a) — — 12 Stock-based compensation (b) 1 (3 ) — Deferred tax impact of U.S. tax reform (c) 112 — — Other (2 ) (2 ) (3 ) Total increase 133 17 28 Total income tax expense $ 375 $ 257 $ 239 Effective income tax rate 54.3 % 37.5 % 39.6 % (a) Represents a valuation allowance against tax credits expiring through 2020 that are more likely than not to expire before being utilized. (b) During 2016, LKE recorded lower income tax expense related to the application of new stock-based compensation accounting guidance. See Note 1 for additional information. (c) During 2017, LKE recorded deferred income

Utility Rate Regulation

Utility Rate Regulation	12 Months Ended
	Dec. 31, 2017
Utility Rate Regulation [Line Items]
Utility Rate Regulation	6. Utility Rate Regulation Regulatory Assets and Liabilities (All Registrants) PPL, PPL Electric, LKE, LG&E and KU reflect the effects of regulatory actions in the financial statements for their cost-based rate-regulated utility operations. Regulatory assets and liabilities are classified as current if, upon initial recognition, the entire amount related to an item will be recovered or refunded within a year of the balance sheet date. (PPL) WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP and does not record regulatory assets and liabilities. See Note 1 for additional information. (PPL, LKE, LG&E and KU) LG&E is subject to the jurisdiction of the KPSC and FERC, and KU is subject to the jurisdiction of the KPSC, FERC and VSCC. LG&E's and KU's Kentucky base rates are calculated based on a return on capitalization (common equity, long-term debt and short-term debt) including adjustments for certain net investments and costs recovered separately through other means. As such, LG&E and KU generally earn a return on regulatory assets. As a result of purchase accounting requirements, certain fair value amounts related to contracts that had favorable or unfavorable terms relative to market were recorded on the Balance Sheets with an offsetting regulatory asset or liability. LG&E and KU recover in customer rates the cost of power purchases. As a result, management believes the regulatory assets and liabilities created to offset the fair value amounts at LKE's acquisition date meet the recognition criteria established by existing accounting guidance and eliminate any rate-making impact of the fair value adjustments. LG&E's and KU's customer rates continue to reflect the original contracted prices for remaining contracts. (PPL, LKE and KU) KU's Virginia base rates are calculated based on a return on rate base (net utility plant plus working capital less deferred taxes and miscellaneous deductions). All regulatory assets and liabilities, except the levelized fuel factor, are excluded from the return on rate base utilized in the calculation of Virginia base rates. Therefore, no return is earned on the related assets. KU's rates to municipal customers for wholesale requirements are calculated based on annual updates to a rate formula that utilizes a return on rate base (net utility plant plus working capital less deferred taxes and miscellaneous deductions). All regulatory assets and liabilities, except regulatory assets recorded for AROs related to certain CCR impoundments, are excluded from the return on rate base utilized in the development of municipal rates. Therefore, no return is earned on the related assets. (PPL and PPL Electric) PPL Electric's distribution base rates are calculated based on recovery of costs as well as a return on distribution rate base (net utility plant plus a working capital allowance less plant-related deferred taxes and other miscellaneous additions and deductions). PPL Electric's transmission revenues are billed in accordance with a FERC tariff that allows for recovery of transmission costs incurred, a return on transmission-related rate base (net utility plant plus a working capital allowance less plant-related deferred taxes and other miscellaneous additions and deductions) and an automatic annual update. See "Transmission Formula Rate" below for additional information on this tariff. All regulatory assets and liabilities are excluded from distribution and transmission return on investment calculations; therefore, generally no return is earned on PPL Electric's regulatory assets. (All Registrants) The following table provides information about the regulatory assets and liabilities of cost-based rate-regulated utility operations at December 31, : PPL PPL Electric 2017 2016 2017 2016 Current Regulatory Assets: Environmental cost recovery $ 5 $ 6 $ — $ — Generation formula rate 6 11 — — Transmission service charge — 7 — 7 Gas supply clause 4 3 — — Smart meter rider 15 6 15 6 Storm costs — 5 — 5 Other 4 1 1 1 Total current regulatory assets (a) $ 34 $ 39 $ 16 $ 19 Noncurrent Regulatory Assets: Defined benefit plans $ 880 $ 947 $ 504 $ 549 Taxes recoverable through future rates 3 340 3 340 Storm costs 33 57 — 9 Unamortized loss on debt 54 61 29 36 Interest rate swaps 26 31 — — Terminated interest rate swaps 92 98 — — Accumulated cost of removal of utility plant 173 159 173 159 AROs 234 211 — — Other 9 14 — 1 Total noncurrent regulatory assets $ 1,504 $ 1,918 $ 709 $ 1,094 Current Regulatory Liabilities: Generation supply charge $ 34 $ 23 $ 34 $ 23 Transmission service charge 9 — 9 — Universal service rider 26 14 26 14 Transmission formula rate 9 15 9 15 Fuel adjustment clauses 3 11 — — Act 129 compliance rider — 17 — 17 Storm damage expense rider 8 13 8 13 Other 6 8 — 1 Total current regulatory liabilities $ 95 $ 101 $ 86 $ 83 Noncurrent Regulatory Liabilities: Accumulated cost of removal of utility plant $ 677 $ 700 $ — $ — Power purchase agreement - OVEC (b) 68 75 — — Net deferred taxes (c) 1,853 23 668 — Defined benefit plans 27 23 — — Terminated interest rate swaps 74 78 — — Other 5 — — — Total noncurrent regulatory liabilities $ 2,704 $ 899 $ 668 $ — LKE LG&E KU 2017 2016 2017 2016 2017 2016 Current Regulatory Assets: Environmental cost recovery $ 5 $ 6 $ 5 $ 6 $ — $ — Generation formula rate 6 11 — — 6 11 Gas supply clause 4 3 4 3 — — Other 3 — 3 — — — Total current regulatory assets $ 18 $ 20 $ 12 $ 9 $ 6 $ 11 LKE LG&E KU 2017 2016 2017 2016 2017 2016 Noncurrent Regulatory Assets: Defined benefit plans $ 376 $ 398 $ 234 $ 246 $ 142 $ 152 Storm costs 33 48 18 26 15 22 Unamortized loss on debt 25 25 16 16 9 9 Interest rate swaps 26 31 26 31 — — Terminated interest rate swaps 92 98 54 57 38 41 AROs 234 211 61 70 173 141 Other 9 13 2 4 7 9 Total noncurrent regulatory assets $ 795 $ 824 $ 411 $ 450 $ 384 $ 374 Current Regulatory Liabilities: Demand side management $ — $ 3 $ — $ 2 $ — $ 1 Fuel adjustment clause 3 11 — 2 3 9 Gas line tracker 3 — 3 — — — Other 3 4 — 1 3 3 Total current regulatory liabilities $ 9 $ 18 $ 3 $ 5 $ 6 $ 13 Noncurrent Regulatory Liabilities: Accumulated cost of removal of utility plant $ 677 $ 700 $ 282 $ 305 $ 395 $ 395 Power purchase agreement - OVEC (b) 68 75 47 52 21 23 Net deferred taxes (c) 1,185 23 552 23 633 — Defined benefit plans 27 23 — — 27 23 Terminated interest rate swaps 74 78 37 39 37 39 Other 5 — 1 — 4 — Total noncurrent regulatory liabilities $ 2,036 $ 899 $ 919 $ 419 $ 1,117 $ 480 (a) For PPL, these amounts are included in "Other current assets" on the Balance Sheets. (b) This liability was recorded as an offset to an intangible asset that was recorded at fair value upon the acquisition of LKE by PPL. (c) Primarily relates to excess deferred taxes recorded as a result of the TCJA, which lowered the federal corporate income tax rate effective January 1, 2018 requiring deferred tax balances and the associated regulatory liabilities to be remeasured as of December 31, 2017. Following is an overview of selected regulatory assets and liabilities detailed in the preceding tables. Specific developments with respect to certain of these regulatory assets and liabilities are discussed in "Regulatory Matters." Defined Benefit Plans (All Registrants) Defined benefit plan regulatory assets and liabilities represent prior service cost and net actuarial gains and losses that will be recovered in defined benefit plans expense through future base rates based upon established regulatory practices and, generally, are amortized over the average remaining service lives of plan participants. These regulatory assets and liabilities are adjusted at least annually or whenever the funded status of defined benefit plans is remeasured. Of the regulatory asset and liability balances recorded, costs of $68 million for PPL, $30 million for PPL Electric, $38 million for LKE, $26 million for LG&E and $12 million for KU, are expected to be amortized into net periodic defined benefit costs in 2018 in accordance with PPL's, PPL Electric's, LKE's, LG&E's and KU's pension accounting policy. (PPL, LKE, LG&E and KU) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between pension cost calculated in accordance with LG&E's and KU's pension accounting policy and pension cost calculated using a 15 -year amortization period for actuarial gains and losses is recorded as a regulatory asset. As of December 31, 2017 , the balances were $33 million for PPL and LKE, $18 million for LG&E and $15 million for KU. As of December 31, 2016 , the balances were $20 million for PPL and LKE, $11 million for LG&E and $9 million for KU. Of the costs expected to be amortized into net periodic defined benefit costs in 2018, $16 million for PPL and LKE, $10 million for LG&E and $6 million for KU, are expected to be recorded as a regulatory asset in 2018. (All Registrants) Storm Costs PPL Electric, LG&E and KU have the ability to request from the PUC, KPSC and VSCC, as applicable, the authority to treat expenses related to specific extraordinary storms as a regulatory asset and defer such costs for regulatory accounting and reporting purposes. Once such authority is granted, LG&E and KU can request recovery of those expenses in a base rate case and begin amortizing the costs when recovery starts. PPL Electric can recover qualifying expenses caused by major storm events, as defined in its retail tariff, over three years through the Storm Damage Expense Rider commencing in the application year after the storm occurred. PPL Electric's, LG&E's and KU's regulatory assets for storm costs are being amortized through various dates ending in 2020 . Unamortized Loss on Debt Unamortized loss on reacquired debt represents losses on long-term debt reacquired or redeemed that have been deferred and will be amortized and recovered over either the original life of the extinguished debt or the life of the replacement debt (in the case of refinancing). Such costs are being amortized through 2029 for PPL Electric, through 2042 for KU, and through 2044 for PPL, LKE and LG&E. Accumulated Cost of Removal of Utility Plant LG&E and KU charge costs of removal through depreciation expense with an offsetting credit to a regulatory liability. The regulatory liability is relieved as costs are incurred. PPL Electric does not accrue for costs of removal. When costs of removal are incurred, PPL Electric records the costs as a regulatory asset. Such deferral is included in rates and amortized over the subsequent five -year period. Regulatory Liability Associated with Net Deferred Taxes Regulatory liabilities associated with net deferred taxes represent the future revenue impact from the adjustment of deferred income taxes required primarily for excess deferred taxes and unamortized investment tax credits. At December 31, 2017, excess deferred taxes recorded as a result of the TCJA were $2.2 billion at PPL, $1.0 billion at PPL Electric, $1.2 billion at LKE, $532 million at LG&E and $634 million at KU, which include the gross-up associated with the excess deferred taxes. (PPL and PPL Electric) Generation Supply Charge (GSC) The GSC is a cost recovery mechanism that permits PPL Electric to recover costs incurred to provide generation supply to PLR customers who receive basic generation supply service. The recovery includes charges for generation supply (energy and capacity and ancillary services), as well as administration of the acquisition process. In addition, the GSC contains a reconciliation mechanism whereby any over- or under-recovery from prior quarters is refunded to, or recovered from, customers through the adjustment factor determined for the subsequent rate filing period. Transmission Service Charge (TSC) PPL Electric is charged by PJM for transmission service-related costs applicable to its PLR customers. PPL Electric passes these costs on to customers, who receive basic generation supply service through the PUC-approved TSC cost recovery mechanism. The TSC contains a reconciliation mechanism whereby any over- or under-recovery from customers is either refunded to, or recovered from, customers through the adjustment factor determined for the subsequent year. Transmission Formula Rate PPL Electric's transmission revenues are billed in accordance with a FERC-approved Open Access Transmission Tariff that utilizes a formula-based rate recovery mechanism. Under this formula, rates are put into effect in June of each year based upon prior year actual expenditures and current year forecasted capital additions. Rates are then adjusted the following year to reflect actual annual expenses and capital additions, as reported in PPL Electric's annual FERC Form 1, filed under the FERC's Uniform System of Accounts. Any difference between the revenue requirement in effect for the prior year and actual expenditures incurred for that year is recorded as a regulatory asset or regulatory liability. Storm Damage Expense Rider (SDER) The SDER is a reconcilable automatic adjustment clause under which PPL Electric annually will compare actual storm costs to storm costs allowed in base rates and refund or recover any differences from customers. In the 2015 rate case settlement approved by the PUC in November 2015, it was determined that reportable storm damage expenses to be recovered annually through base rates will be set at $15 million . The SDER will recover from or refund to customers, as appropriate, only applicable expenses from reportable storms that are greater than or less than $15 million recovered annually through base rates. Beginning January 1, 2018, the amortized 2011 storm expense of $5 million will be included in the base rate component of the SDER. Taxes Recoverable through Future Rates Taxes recoverable through future rates represent the portion of future income taxes that will be recovered through future rates based upon established regulatory practices. Accordingly, this regulatory asset is recognized when the offsetting deferred tax liability is recognized. For general-purpose financial reporting, this regulatory asset and the deferred tax liability are not offset; rather, each is displayed separately. This regulatory asset is expected to be recovered over the period that the underlying book-tax timing differences reverse and the actual cash taxes are incurred. Act 129 Compliance Rider In compliance with Pennsylvania's Act 129 of 2008 and implementing regulations, Phase I of PPL Electric's energy efficiency and conservation plan was approved by a PUC order in October 2009. The order allowed PPL Electric to recover the maximum $250 million cost of the program ratably over the life of the plan, from January 1, 2010 through May 31, 2013. Phase II of PPL's energy efficiency and conservation plan allowed PPL Electric to recover the maximum $185 million cost of the program over the three year period June 1, 2013 through May 31, 2016 . Phase III of PPL's energy efficiency and conservation plan allows PPL Electric to recover the maximum $313 million over the next five year period, June 1, 2016 through May 31, 2021. The plan includes programs intended to reduce electricity consumption. The recoverable costs include direct and indirect charges, including design and development costs, general and administrative costs and applicable state evaluator costs. The rates are applied to customers who receive distribution service through the Act 129 Compliance Rider. The Phase II program costs were reconciled at the end of the program and any remaining over- or under-recovery was rolled into Phase III. The actual Phase III program costs are reconcilable after each 12 month period, and any over- or under-recovery from customers will be refunded or recovered over the next rate filing period. See below under "Regulatory Matters - Pennsylvania Activities" for additional information on Act 129. Smart Meter Rider (SMR) Act 129, which became effective November 14, 2008, requires each electric distribution company (EDC) with more than 100,000 customers to have a PUC approved Smart Meter Technology Procurement and Installation Plan (SMP). PPL Electric filed its initial SMP in 2009. However, in 2010, the PUC found that PPL Electric's "Advanced Metering Infrastructure" (AMI) system did not fully meet the standards of Act 129. In 2014, PPL Electric filed its current SMP, which was approved by the PUC in 2015. Under its SMP, PPL Electric will replace its current meters with new meters that meet the Act 129 requirements by the end of 2019. Under Act 129, EDCs are able to recover the costs of providing smart metering technology. PPL Electric uses a mechanism known as the Smart Meter Rider (SMR) to recover the costs to implement its SMP on a full and current basis. The SMR is a reconciliation mechanism whereby any over-or under-recovery from prior years is refunded to, or recovered from, customers through the adjustment factor determined for the subsequent quarters. Universal Service Rider (USR) The USR provides for recovery of costs associated with universal service programs, OnTrack and Winter Relief Assistance Program (WRAP), provided by PPL Electric to residential customers. OnTrack is a special payment program for low-income households and WRAP provides low-income customers a means to reduce electric bills through energy saving methods. The USR rate is applied to residential customers who receive distribution service. The actual program costs are reconcilable, and any over- or under-recovery from customers will be refunded or recovered annually in the subsequent year. (PPL, LKE, LG&E and KU) Environmental Cost Recovery Kentucky law permits LG&E and KU to recover the costs, including a return of operating expenses and a return of and on capital invested, of complying with the Clean Air Act and those federal, state or local environmental requirements, which apply to coal combustion wastes and by-products from coal-fired electricity generating facilities. The KPSC requires reviews of the past operations of the environmental surcharge for six-month and two-year billing periods to evaluate the related charges, credits and rates of return, as well as to provide for the roll-in of ECR amounts to base rates each two-year period. In December 2017, the KPSC issued orders continuing the use of an authorized return on equity of 9.7% for all existing approved ECR plans and projects. The ECR regulatory asset or liability represents the amount that has been under- or over-recovered due to timing or adjustments to the mechanism and is typically recovered within 12 months . Fuel Adjustment Clauses LG&E's and KU's retail electric rates contain a fuel adjustment clause, whereby variances in the cost of fuel to generate electricity, including transportation costs, from the costs embedded in base rates are adjusted in LG&E's and KU's rates. The KPSC requires public hearings at six-month intervals to examine past fuel adjustments and at two-year intervals to review past operations of the fuel adjustment clause and, to the extent appropriate, reestablish the fuel charge included in base rates. The regulatory assets or liabilities represent the amounts that have been under- or over-recovered due to timing or adjustments to the mechanism and are typically recovered within 12 months . KU also employs a levelized fuel factor mechanism for Virginia customers using an average fuel cost factor based primarily on projected fuel costs. The Virginia levelized fuel factor allows fuel recovery based on projected fuel costs for the coming year plus an adjustment for any under- or over-recovery of fuel expenses from the prior year. The regulatory assets or liabilities represent the amounts that have been under- or over-recovered due to timing or adjustments to the mechanism and are typically recovered within 12 months . Demand Side Management LG&E's and KU's DSM programs consist of energy efficiency programs, intended to reduce peak demand and delay investment in additional power plant construction, provide customers with tools and information to become better managers of their energy usage and prepare for potential future legislation governing energy efficiency. LG&E's and KU's rates contain a DSM provision, which includes a rate recovery mechanism that provides for concurrent recovery of DSM costs and incentives, and allows for the recovery of DSM revenues from lost sales associated with the DSM programs. Additionally, LG&E and KU earn an approved return on equity for capital expenditures associated with the residential and commercial load management and demand conservation programs. The cost of DSM programs is assigned only to the class or classes of customers that benefit from the programs. AROs As discussed in Note 1, for LKE, LG&E and KU, all ARO accretion and depreciation expenses are reclassified as a regulatory asset. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, at the time of retirement, the related ARO regulatory asset is offset against the associated cost of removal regulatory liability, PP&E and ARO liability. Power Purchase Agreement - OVEC As a result of purchase accounting associated with PPL's acquisition of LKE, the fair values of the OVEC power purchase agreement were recorded on the balance sheets of LKE, LG&E and KU with offsets to regulatory liabilities. The regulatory liabilities are being amortized using the units-of-production method until March 2026 , the expiration date of the agreement at the date of the acquisition. See Notes 1, 13 and 18 for additional discussion of the power purchase agreement. Interest Rate Swaps LG&E's unrealized gains and losses are recorded as regulatory assets or regulatory liabilities until they are realized as interest expense. Interest expense from existing swaps is realized and recovered over the terms of the associated debt, which matures through 2033 . Terminated Interest Rate Swaps Net realized gains and losses on all interest rate swaps are probable of recovery through regulated rates; as such, any gains and losses on these derivatives are included in regulatory assets or liabilities and are primarily recognized in "Interest Expense" on the Statements of Income over the life of the associated debt. A net cash settlement of $9 million was paid on a swap that was terminated by LG&E in December 2016. The KPSC authorized the recording of a regulatory asset and the recovery of such costs. As part of the Stipulation to the 2016 Kentucky rate case that became effective July 1, 2017, the KPSC authorized LG&E to recover the swap termination payment through amortization of the regulatory asset using a straight-line method over 17 years . The amortization of the regulatory asset is recognized in "Interest Expense" on the Statements of Income. Plant Outage Costs The Stipulation to the 2016 Kentucky rate case that became effective July 1, 2017 provided for the normalization of expenses associated with plant outages using an eight-year average. The eight-year average is comprised of four historical years' and four forecasted years' expenses. Plant outage expenses that are greater or less than the eight-year average will be collected from or returned to customers, through future base rates. These amounts are included in other current regulatory assets or other current regulatory liabilities above. (PPL, LKE and LG&E) Gas Line Tracker The GLT authorizes LG&E to recover its incremental operating expenses, depreciation, property taxes and cost of capital, including a return on equity, for capital associated with the five year gas service riser, leak mitigation and customer service line ownership programs. As part of this program, LG&E makes necessary repairs to the gas distribution system and assumes ownership of service lines when replaced. In the 2016 rate case, the KPSC approved additional projects for recovery through the GLT mechanism related to further gas line replacements and transmission pipeline modernizations. Effective July 1, 2017, LG&E is authorized to earn a 9.7% return on equity for the GLT mechanism. As part of the 2016 rate case, LG&E now annually files a combined application which includes revised rates based on projected costs and a balancing adjustment calculation with rates effective on the first billing cycle in May. After the completion of a plan year, the balancing adjustment, as part of the combined application filing to the KPSC, amends rates charged for the differences between the actual costs and actual GLT charges for the preceding year. The regulatory assets or liabilities represent the amounts that have been under- or over-recovered due to these cost differences. Gas Supply Clause LG&E's natural gas rates contain a gas supply clause, whereby the expected cost of natural gas supply and variances between actual and expected costs from prior periods are adjusted quarterly in LG&E's rates, subject to approval by the KPSC. The gas supply clause also includes a separate natural gas procurement incentive mechanism, which allows LG&E's rates to be adjusted annually to share savings between the actual cost of gas purchases and market indices with the shareholders and the customers during each performance-based rate year (12 months ending October 31). The regulatory assets or liabilities represent the total amounts that have been under- or over-recovered due to timing or adjustments to the mechanisms and are typically recovered within 18 months . (PPL, LKE and KU) Generation Formula Rates KU provides wholesale requirements service to its municipal customers and bills for this service pursuant to a FERC approved generation formula rate. Under this formula, rates are put into effect in July of each year utilizing a return on rate base calculation and actual expenses from the preceding year. The regulatory asset represents the difference between the revenue requirement in effect for the preceding year and actual expenditures incurred for the current year. Regulatory Matters (PPL) U.K. Activities RIIO-ED1 On April 1, 2015, the RIIO-ED1 eight-year price control period commenced for WPD's four DNOs. (PPL, LKE, LG&E and KU) Kentucky Activities Rate Case Proceedings In November 2016, LG&E and KU filed requests with the KPSC for increases in annual base electricity and gas rates. LG&E's and KU's applications included requests for CPCNs for implementing an Advanced Metering System program and a Distribution Automation program. In April and May 2017, LG&E and KU, along with all intervening parties to the proceeding, filed with the KPSC, stipulation and recommendation agreements (stipulations) resolving all issues with the parties. Among other things, the proposed stipulations provided for increases in annual revenue requirements associated with LG&E base electricity rates of $59 million , LG&E base gas rates of $8 million and KU base electricity rates of $55 million , reflecting a return on equity of 9.75% , the withdrawal of LG&E's and KU's request for a CPCN for the Advanced Metering System and other changes to the revenue requirements, which dealt primarily with the timing of cost recovery, including depreciation rates. In June 2017, the KPSC issued orders approving, with certain modifications, the proposed stipulations filed in April and May 2017. The orders modified the stipulations to provide for increases in annual revenue requirements associated with LG&E base electricity rates of $57 million , LG&E base gas rates of $7 million , KU base electricity rates of $52 million and incorporated an authorized return on equity of 9.7% . Consistent with the stipulations, the orders approved LG&E's and KU's request for implementing a Distribution Automation program and their withdrawal of a request for a CPCN for the Advanced Metering System program. The orders also approved new depreciation rates for LG&E and KU that resulted in higher depreciation of approximately $15 million ( $4 million for LG&E and $11 million for KU) in 2017, exclusive of net additions to PP&E. The orders resulted in base electricity and gas rate increases of 5.2% and 2.1% at LG&E and a base electricity rate increase of 3.2% at KU. The new base rates and all elements of the orders became effective July 1, 2017. On June 23, 2017, the KPSC issued orders establishing an authorized return on equity of 9.7% for all of LG&E's and KU's existing approved ECR plans and projects, replacing the prior authorized return on equity levels of 9.8% for CCR projects and 10% for all other ECR approved projects, effective with bills issued in August 2017. The annual impact of the new authorized return for ECR projects is not expected to be significant. CPCN Filing On January 10, 2018, LG&E and KU filed an application for a CPCN with the KPSC requesting approval for implementing Advanced Metering Systems across their Kentucky service territories, including gas operations for LG&E. The full deployment is expected to be completed in 2021 with estimated capital costs of $155 million and $104 million for KU and LG&E electric service and $62 million for LG&E gas service. The full Advanced Metering Systems deployment will also result in incremental operation and maintenance costs during the deployment phase of $17 million and $11 million for KU and LG&E electric service and $3 million for LG&E gas service. TCJA Impact on LG&E and KU Rates On December 21, 2017, Kentucky Industrial Utility Customers, Inc. submitted a complaint with the KPSC against LG&E and KU, as well as other utility companies in Kentucky, alleging that their respective rates would no longer be fair, just and reasonable following the enactment of the TCJA reducing the federal corporate tax rate from 35% to 21%. The complaint requested the KPSC to issue an order requiring LG&E and KU to begin deferring, as of January 1, 2018, the revenue requirement effect of all income tax expense savings resulting from the federal corporate income tax reduction, including the amortization of excess deferred income taxes by recording those savings in a regulatory liability account and establishing a process by which the federal corporate income tax savings will be passed back to customers. On December 27, 2017, as a result of the complaint, the KPSC ordered LG&E and KU to satisfy or address the complaint and commence recording regulatory liabilities to reflect the reduction in the federal corporate tax rate to 21% and the associated savings in excess deferred taxes on an interim basis until utility rates are adjusted to reflect the federal tax savings. On January 8, 2018, LG&E and KU responded to the complaint, denying certain claims in the complaint but concurring that the TCJA will result in savings for their customers. LG&E and KU have stated in their responses that the companies have recorded regulatory liabilities as of December 31, 2017 to reflect the reduction in the federal corporate tax rate and the associated savings in excess deferred taxes and will make changes to their ECR, DSM and LG&E's GLT rate mechanisms to begin providing the applicable savings to customers. LG&E and KU also offered to establish a new bill credit mechanism effective with the April 2018 billing cycle to begin distributing the tax savings associated with base rates to customers. On January 29, 2018, LG&E and KU reached a settlement agreement to commence returning savings related to the TCJA to their customers. The savings will be distributed through their ECR, DSM and LG&E's GLT rate mechanisms beginning in March 2018 and through a new bill credit mechanism from April 1, 2018 through April 30, 2019 . The estimated impact of the rate reduction represents approximately $91 million in KU electricity revenues, $69 million in LG&E electricity revenues and $17 million in LG&E gas revenues for the period January 2018 through April 2019. Ongoing tax savings are expected to also be addressed in LG&E's and KU's next Kentucky base rate case. LG&E and KU have indicated their intent to file an application for base rate changes during 2018 to be effective during spring 2019. The settlement agreement is subject to review and approval by the KPSC. An order in the proceeding may occur during the first quarter of 2018. Additionally, on January 8, 2018, the VSCC ordered KU, as well as other utilities in Virginia, to accrue regulatory liabilities reflecting the Virginia jurisdictional revenue requirement impacts of the reduced federal corporate tax rate. The FERC has not issued any guidance on the effect on rates of the TCJA. LG&E and KU cannot predict the outcome of these proceedings. (LKE and LG&E) Gas Franchise LG&E’

Financing Activities

Financing Activities	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Financing Activities	7. Financing Activities Credit Arrangements and Short-term Debt (All Registrants) The Registrants maintain credit facilities to enhance liquidity, provide credit support and provide a backstop to commercial paper programs. For reporting purposes, on a consolidated basis, the credit facilities and commercial paper programs of PPL Electric, LKE, LG&E and KU also apply to PPL and the credit facilities and commercial paper programs of LG&E and KU also apply to LKE. The amounts borrowed below are recorded as "Short-term debt" on the Balance Sheets except for borrowings under LG&E's Term Loan Facility which are recorded as "Long-term debt" on the Balance Sheets. The following credit facilities were in place at: December 31, 2017 December 31, 2016 Expiration Date Capacity Borrowed Letters of Credit and Commercial Paper Issued Unused Capacity Borrowed Letters of Credit and Commercial Paper Issued PPL U.K. WPD plc Syndicated Credit Facility (a) (c) Jan. 2022 £ 210 £ 148 £ — £ 60 £ 160 £ — WPD (South West) Syndicated Credit Facility (a) (c) July 2021 245 — — 245 110 — WPD (East Midlands) Syndicated Credit Facility (a) (c) July 2021 300 180 — 120 9 — WPD (West Midlands) Syndicated Credit Facility (a) (c) July 2021 300 120 — 180 — — Uncommitted Credit Facilities 100 — 4 96 60 4 Total U.K. Credit Facilities (b) £ 1,155 £ 448 £ 4 £ 701 £ 339 £ 4 U.S. PPL Capital Funding Syndicated Credit Facility (c) (d) Jan. 2022 $ 950 $ — $ 230 $ 720 $ — $ 20 Syndicated Credit Facility (c) (d) Nov. 2018 300 — — 300 — — Bilateral Credit Facility (c) (d) Mar. 2018 150 — 18 132 — 17 Total PPL Capital Funding Credit Facilities $ 1,400 $ — $ 248 $ 1,152 $ — $ 37 PPL Electric Syndicated Credit Facility (c) (d) Jan. 2022 $ 650 $ — $ 1 $ 649 $ — $ 296 LKE Syndicated Credit Facility (c) (d) Oct. 2018 $ 75 $ — $ — $ 75 $ — $ — LG&E Syndicated Credit Facility (c) (d) Jan. 2022 $ 500 $ — $ 199 $ 301 $ — $ 169 Term Loan Credit Facility (c) (e) Oct. 2019 200 100 — 100 — — Total LG&E Credit Facilities $ 700 $ 100 $ 199 $ 401 $ — $ 169 KU Syndicated Credit Facility (c) (d) Jan. 2022 $ 400 $ — $ 45 $ 355 $ — $ 16 Letter of Credit Facility (c) (d) (f) Oct. 2020 198 — 198 — — 198 Total KU Credit Facilities $ 598 $ — $ 243 $ 355 $ — $ 214 (a) The facilities contain financial covenants to maintain an interest coverage ratio of not less than 3.0 times consolidated earnings before income taxes, depreciation and amortization and total net debt not in excess of 85% of its RAV, calculated in accordance with the credit facility. (b) The WPD plc amounts borrowed at December 31, 2017 and 2016 included USD-denominated borrowings of $200 million for both periods, which bore interest at 2.17% and 1.43% . The unused capacity reflects the amount borrowed in GBP of £150 million as of the date borrowed. The WPD (East Midlands) amount borrowed at December 31, 2017 was a GBP-denominated borrowing, which equated to $244 million and bore interest at 0.89% . The WPD (West Midlands) amount borrowed at December 31, 2017 was a GBP-denominated borrowing, which equated to $162 million and bore interest at 0.89% . At December 31, 2017 , the unused capacity under the U.K. credit facilities was approximately $949 million . (c) Each company pays customary fees under its respective facility and borrowings generally bear interest at LIBOR-based rates plus an applicable margin. (d) The facilities contain a financial covenant requiring debt to total capitalization not to exceed 70% for PPL Capital Funding, PPL Electric, LKE, LG&E and KU, as calculated in accordance with the facilities and other customary covenants. Additionally, as it relates to the syndicated and bilateral credit facilities and subject to certain conditions, PPL Capital Funding may request that the capacity of its facilities expiring in November 2018 and March 2018 be increased by up to $30 million , LG&E and KU each may request up to a $100 million increase in its facility's capacity and LKE may request up to a $25 million increase in its facility's capacity. (e) LG&E entered into a term loan credit agreement in October 2017 whereby it may borrow up to $200 million . The outstanding borrowings at December 31, 2017 bore interest at a rate of 2.06% . (f) KU's letter of credit facility agreement allows for certain payments under the letter of credit facility to be converted to loans rather than requiring immediate payment. In January 2018, LG&E borrowed the remaining $100 million available under its $200 million term loan facility. The proceeds were used to repay short-term debt and for general corporate purposes. In January 2018, the expiration dates for the PPL Capital Funding, PPL Electric, LG&E and KU syndicated credit facilities expiring in January 2022 were extended to January 2023 . PPL, PPL Electric, LG&E and KU maintain commercial paper programs to provide an additional financing source to fund short-term liquidity needs, as necessary. Commercial paper issuances, included in "Short-term debt" on the Balance Sheets, are supported by the respective Registrant's Syndicated Credit Facility. The following commercial paper programs were in place at: December 31, 2017 December 31, 2016 Weighted - Capacity Commercial Unused Weighted - Commercial PPL Capital Funding 1.64% $ 1,000 $ 230 $ 770 1.10% $ 20 PPL Electric 650 — 650 1.05% 295 LG&E 1.83% 350 199 151 0.94% 169 KU 1.97% 350 45 305 0.87% 16 Total $ 2,350 $ 474 $ 1,876 $ 500 (PPL Electric, LKE, LG&E and KU) See Note 14 for discussion of intercompany borrowings. Long-term Debt (All Registrants) December 31, Weighted-Average Maturities (g) 2017 2016 PPL U.S. Senior Unsecured Notes 3.78 % 2020 - 2047 $ 4,575 $ 4,075 Senior Secured Notes/First Mortgage Bonds (a) (b) (c) 3.96 % 2018 - 2047 7,314 6,849 Junior Subordinated Notes 5.10 % 2067 - 2073 930 930 Term Loan Credit Facility 2.06 % 2019 100 — Total U.S. Long-term Debt 12,919 11,854 U.K. Senior Unsecured Notes (d) 5.24 % 2020 - 2040 6,351 5,707 Index-linked Senior Unsecured Notes (e) 1.56 % 2026 - 2056 1,012 838 Total U.K. Long-term Debt (f) 7,363 6,545 Total Long-term Debt Before Adjustments 20,282 18,399 Fair market value adjustments 21 22 Unamortized premium and (discount), net (e) 14 20 Unamortized debt issuance costs (122 ) (115 ) Total Long-term Debt 20,195 18,326 Less current portion of Long-term Debt 348 518 Total Long-term Debt, noncurrent $ 19,847 $ 17,808 December 31, Weighted-Average Maturities (g) 2017 2016 PPL Electric Senior Secured Notes/First Mortgage Bonds (a) (b) 4.23 % 2020 - 2047 $ 3,339 $ 2,864 Total Long-term Debt Before Adjustments 3,339 2,864 Unamortized discount (16 ) (12 ) Unamortized debt issuance costs (25 ) (21 ) Total Long-term Debt 3,298 2,831 Less current portion of Long-term Debt — 224 Total Long-term Debt, noncurrent $ 3,298 $ 2,607 LKE Senior Unsecured Notes 3.97 % 2020 - 2021 $ 725 $ 725 Term Loan Credit Facility 2.06 % 2019 100 — First Mortgage Bonds (a) (c) 3.73 % 2018 - 2045 3,975 3,985 Long-term debt to affiliate 3.50 % 2026 400 400 Total Long-term Debt Before Adjustments 5,200 5,110 Fair market value adjustments — (1 ) Unamortized discount (14 ) (15 ) Unamortized debt issuance costs (27 ) (29 ) Total Long-term Debt 5,159 5,065 Less current portion of Long-term Debt 98 194 Total Long-term Debt, noncurrent $ 5,061 $ 4,871 LG&E Term Loan Credit Facility 2.06 % 2019 $ 100 $ — First Mortgage Bonds (a) (c) 3.48 % 2018 - 2045 1,624 1,634 Total Long-term Debt Before Adjustments 1,724 1,634 Fair market value adjustments — (1 ) Unamortized discount (4 ) (4 ) Unamortized debt issuance costs (11 ) (12 ) Total Long-term Debt 1,709 1,617 Less current portion of Long-term Debt 98 194 Total Long-term Debt, noncurrent $ 1,611 $ 1,423 KU First Mortgage Bonds (a) (c) 3.91 % 2019 - 2045 $ 2,351 $ 2,351 Total Long-term Debt Before Adjustments 2,351 2,351 Unamortized discount (9 ) (9 ) Unamortized debt issuance costs (14 ) (15 ) Total Long-term Debt 2,328 2,327 Less current portion of Long-term Debt — — Total Long-term Debt, noncurrent $ 2,328 $ 2,327 (a) Includes PPL Electric's senior secured and first mortgage bonds that are secured by the lien of PPL Electric's 2001 Mortgage Indenture, which covers substantially all electric distribution plant and certain transmission plant owned by PPL Electric. The carrying value of PPL Electric's property, plant and equipment was approximately $8.5 billion and $7.6 billion at December 31, 2017 and 2016 . Includes LG&E's first mortgage bonds that are secured by the lien of the LG&E 2010 Mortgage Indenture which creates a lien, subject to certain exceptions and exclusions, on substantially all of LG&E's real and tangible personal property located in Kentucky and used or to be used in connection with the generation, transmission and distribution of electricity and the storage and distribution of natural gas. The aggregate carrying value of the property subject to the lien was $4.7 billion and $4.4 billion at December 31, 2017 and 2016 . Includes KU's first mortgage bonds that are secured by the lien of the KU 2010 Mortgage Indenture which creates a lien, subject to certain exceptions and exclusions, on substantially all of KU's real and tangible personal property located in Kentucky and used or to be used in connection with the generation, transmission and distribution of electricity. The aggregate carrying value of the property subject to the lien was $6.0 billion and $5.8 billion at December 31, 2017 and 2016 . (b) Includes PPL Electric's series of senior secured bonds that secure its obligations to make payments with respect to each series of Pollution Control Bonds that were issued by the LCIDA and the PEDFA on behalf of PPL Electric. These senior secured bonds were issued in the same principal amount, contain payment and redemption provisions that correspond to and bear the same interest rate as such Pollution Control Bonds. These senior secured bonds were issued under PPL Electric's 2001 Mortgage Indenture and are secured as noted in (a) above. This amount includes $224 million of which PPL Electric is allowed to convert the interest rate mode on the bonds from time to time to a commercial paper rate, daily rate, weekly rate, or term rate of at least one year and $90 million that may be redeemed, in whole or in part, at par beginning in October 2020 , and are subject to mandatory redemption upon determination that the interest rate on the bonds would be included in the holders' gross income for federal tax purposes. (c) Includes LG&E's and KU's series of first mortgage bonds that were issued to the respective trustees of tax-exempt revenue bonds to secure its respective obligations to make payments with respect to each series of bonds. The first mortgage bonds were issued in the same principal amounts, contain payment and redemption provisions that correspond to and bear the same interest rate as such tax-exempt revenue bonds. These first mortgage bonds were issued under the LG&E 2010 Mortgage Indenture and the KU 2010 Mortgage Indenture and are secured as noted in (a) above. The related tax-exempt revenue bonds were issued by various governmental entities, principally counties in Kentucky, on behalf of LG&E and KU. The related revenue bond documents allow LG&E and KU to convert the interest rate mode on the bonds from time to time to a commercial paper rate, daily rate, weekly rate, term rate of at least one year or, in some cases, an auction rate or a LIBOR index rate. At December 31, 2017 , the aggregate tax-exempt revenue bonds issued on behalf of LG&E and KU that were in a term rate mode totaled $514 million for LKE, comprised of $391 million and $123 million for LG&E and KU. At December 31, 2017 , the aggregate tax-exempt revenue bonds issued on behalf of LG&E and KU that were in a variable rate mode totaled $375 million for LKE, comprised of $147 million and $228 million for LG&E and KU. These variable rate tax-exempt revenue bonds are subject to tender for purchase by LG&E and KU at the option of the holder and to mandatory tender for purchase by LG&E and KU upon the occurrence of certain events. (d) Includes £225 million ( $304 million at December 31, 2017 ) of notes that may be redeemed, in total but not in part, on December 21, 2026 , at the greater of the principal value or a value determined by reference to the gross redemption yield on a nominated U.K. Government bond. (e) The principal amount of the notes issued by WPD (South West), WPD (East Midlands) and WPD (South Wales) is adjusted based on changes in a specified index, as detailed in the terms of the related indentures. The adjustment to the principal amounts from 2016 to 2017 was an increase of approximately £27 million ( $37 million ) resulting from inflation. In addition, this amount includes £225 million ( $304 million at December 31, 2017 ) of notes issued by WPD (South West) that may be redeemed, in total by series, on December 1, 2026 , at the greater of the adjusted principal value and a make-whole value determined by reference to the gross real yield on a nominated U.K. government bond. (f) Includes £4.7 billion ( $6.4 billion at December 31, 2017 ) of notes that may be put by the holders to the issuer for redemption if the long-term credit ratings assigned to the notes are withdrawn by any of the rating agencies (Moody's or S&P) or reduced to a non-investment grade rating of Ba1 or BB+ or lower in connection with a restructuring event, which includes the loss of, or a material adverse change to, the distribution licenses under which the issuer operates. (g) The table reflects principal maturities only, based on stated maturities or earlier put dates, and the weighted-average rates as of December 31, 2017 . None of the outstanding debt securities noted above have sinking fund requirements. The aggregate maturities of long-term debt, based on stated maturities or earlier put dates, for the periods 2018 through 2022 and thereafter are as follows: PPL PPL Electric LKE LG&E KU 2018 $ 348 $ — $ 98 $ 98 $ — 2019 430 — 430 334 96 2020 1,278 100 975 — 500 2021 1,150 400 250 — — 2022 1,274 474 — — — Thereafter 15,802 2,365 3,447 1,292 1,755 Total $ 20,282 $ 3,339 $ 5,200 $ 1,724 $ 2,351 (PPL) In March 2017, WPD (South Wales) issued £50 million of 0.01% Index-linked Senior Notes due 2029 . WPD (South Wales) received proceeds of £53 million , which equated to $64 million at the time of issuance, net of fees and including a premium. The principal amount of the notes is adjusted based on changes in a specified index, as detailed in the terms of the related indenture. The proceeds were used for general corporate purposes. In September 2017, PPL Capital Funding issued $500 million of 4.00% Senior Notes due 2047 . PPL Capital Funding received proceeds of $490 million , net of a discount and underwriting fees, which were used to repay short-term debt obligations and for general corporate purposes. In November 2017, WPD (South West) issued £250 million of 2.375% Senior Notes due 2029 . WPD (South West) received proceeds of £247 million , which equated to $326 million at the time of issuance, net of fees and a discount. The proceeds were used for general corporate purposes, including the re-financing of existing debt. In December 2017, WPD repaid the entire $100 million principal amount of its 7.25% Senior Notes upon maturity. (PPL and PPL Electric) In May 2017, PPL Electric issued $ 475 million of 3.95% First Mortgage Bonds due 2047 . PPL Electric received proceeds of $ 466 million , net of a discount and underwriting fees, which were used to repay short-term debt incurred primarily for capital expenditures. In August 2017, the LCIDA remarketed $ 108 million of Pollution Control Revenue Refunding Bonds (PPL Electric Utilities Corporation Project), Series 2016B due 2027 previously issued on behalf of PPL Electric. The bonds were remarketed at a long-term rate and will bear interest at 1.80% through their mandatory purchase date of August 15, 2022 . In September 2017, the LCIDA remarketed $ 116 million of Pollution Control Revenue Refunding Bonds (PPL Electric Utilities Corporation Project), Series 2016A due 2029 previously issued on behalf of PPL Electric. The bonds were remarketed at a long-term rate and will bear interest at 1.80% through their mandatory purchase date of September 1, 2022 . (PPL, LKE and LG&E) In April 2017, the Louisville/Jefferson County Metro Government of Kentucky remarketed $128 million of Pollution Control Revenue Bonds, 2003 Series A (Louisville Gas and Electric Company Project) due 2033 previously issued on behalf of LG&E. The bonds were remarketed at a long-term rate and will bear interest at 1.50% through their mandatory purchase date of April 1, 2019 . In June 2017, the County of Trimble, Kentucky issued $60 million of Environmental Facilities Revenue Refunding Bonds, 2017 Series A (Louisville Gas and Electric Company Project) due 2033 on behalf of LG&E. The bonds were issued bearing interest at a rate of 3.75% through their maturity and are subject to an optional redemption on or after June 1, 2027 . The proceeds of the bonds were used to redeem $60 million of Environmental Facilities Revenue Refunding Bonds, 2007 Series A (Louisville Gas and Electric Company Project) due 2033 previously issued by the County of Trimble, Kentucky on behalf of LG&E. In June 2017, the Louisville/Jefferson County Metro Government of Kentucky remarketed $31 million of Environmental Facilities Revenue Refunding Bonds, 2007 Series A (Louisville Gas and Electric Company Project) due 2033 previously issued on behalf of LG&E. The bonds were remarketed at a long-term rate and will bear interest at 1.25% through their mandatory purchase date of June 3, 2019 . In June 2017, the Louisville/Jefferson County Metro Government of Kentucky remarketed $35 million of Environmental Facilities Revenue Refunding Bonds, 2007 Series B (Louisville Gas and Electric Company Project) due 2033 previously issued on behalf of LG&E. The bonds were remarketed at a long-term rate and will bear interest at 1.25% through their mandatory purchase date of June 3, 2019 . In October 2017, LG&E entered into a $200 million term loan credit facility with a term expiring in October 2019 . As of December 31, 2017, LG&E had outstanding borrowings of $100 million under this agreement at a rate of 2.06% . In January 2018, LG&E borrowed the remaining $100 million available under this facility. In November 2017, LG&E redeemed, at par, its $10 million Louisville/Jefferson County Metro Government Environmental Facilities Revenue Bonds, 2001 Series A (Louisville Gas and Electric Company Project) due 2027 . Legal Separateness (All Registrants) The subsidiaries of PPL are separate legal entities. PPL's subsidiaries are not liable for the debts of PPL. Accordingly, creditors of PPL may not satisfy their debts from the assets of PPL's subsidiaries absent a specific contractual undertaking by a subsidiary to pay PPL's creditors or as required by applicable law or regulation. Similarly, PPL is not liable for the debts of its subsidiaries, nor are its subsidiaries liable for the debts of one another. Accordingly, creditors of PPL's subsidiaries may not satisfy their debts from the assets of PPL or its other subsidiaries absent a specific contractual undertaking by PPL or its other subsidiaries to pay the creditors or as required by applicable law or regulation. Similarly, the subsidiaries of PPL Electric and LKE are each separate legal entities. These subsidiaries are not liable for the debts of PPL Electric and LKE. Accordingly, creditors of PPL Electric and LKE may not satisfy their debts from the assets of their subsidiaries absent a specific contractual undertaking by a subsidiary to pay the creditors or as required by applicable law or regulation. Similarly, PPL Electric and LKE are not liable for the debts of their subsidiaries, nor are their subsidiaries liable for the debts of one another. Accordingly, creditors of these subsidiaries may not satisfy their debts from the assets of PPL Electric and LKE (or their other subsidiaries) absent a specific contractual undertaking by that parent or other subsidiary to pay such creditors or as required by applicable law or regulation. (PPL) ATM Program In February 2015, PPL entered into two separate equity distribution agreements, pursuant to which PPL may sell, from time to time, up to an aggregate of $500 million of its common stock. The compensation paid to the selling agents by PPL may be up to 1% of the gross offering proceeds of the shares sold with respect to each equity distribution agreement. PPL issued the following for the years ended December 31: 2017 2016 2015 Number of shares (in thousands) 10,373 710 1,477 Net Proceeds $ 377 $ 25 $ 49 Distributions and Related Restrictions In November 2017 , PPL declared its quarterly common stock dividend, payable January 2, 2018 , at 39.5 cents per share (equivalent to $1.58 per annum). On February 22, 2018, PPL announced that the company is increasing its common stock dividend to 41.0 cents per share on a quarterly basis (equivalent to $ 1.64 per annum). Future dividends, declared at the discretion of the Board of Directors, will depend upon future earnings, cash flows, financial and legal requirements and other factors. See Note 8 for information regarding the June 1, 2015 distribution to PPL's shareowners of a newly formed entity, Holdco, which at closing owned all of the membership interests of PPL Energy Supply and all of the common stock of Talen Energy. Neither PPL Capital Funding nor PPL may declare or pay any cash dividend or distribution on its capital stock during any period in which PPL Capital Funding defers interest payments on its 2007 Series A Junior Subordinated Notes due 2067 or 2013 Series B Junior Subordinated Notes due 2073 . At December 31, 2017 , no interest payments were deferred. WPD subsidiaries have financing arrangements that limit their ability to pay dividends. However, PPL does not, at this time, expect that any of such limitations would significantly impact PPL's ability to meet its cash obligations. (All Registrants) PPL relies on dividends or loans from its subsidiaries to fund PPL's dividends to its common shareholders. The net assets of certain PPL subsidiaries are subject to legal restrictions. LKE primarily relies on dividends from its subsidiaries to fund its distributions to PPL. LG&E, KU and PPL Electric are subject to Section 305(a) of the Federal Power Act, which makes it unlawful for a public utility to make or pay a dividend from any funds "properly included in capital account." The meaning of this limitation has never been clarified under the Federal Power Act. LG&E, KU and PPL Electric believe, however, that this statutory restriction, as applied to their circumstances, would not be construed or applied by the FERC to prohibit the payment from retained earnings of dividends that are not excessive and are for lawful and legitimate business purposes. In February 2012, LG&E and KU petitioned the FERC requesting authorization to pay dividends in the future based on retained earnings balances calculated without giving effect to the impact of purchase accounting adjustments for the acquisition of LKE by PPL. In May 2012, the FERC approved the petitions with the further condition that each utility may not pay dividends if such payment would cause its adjusted equity ratio to fall below 30% of total capitalization. Accordingly, at December 31, 2017 , net assets of $2.7 billion ( $1.1 billion for LG&E and $1.6 billion for KU) were restricted for purposes of paying dividends to LKE, and net assets of $3.1 billion ( $1.4 billion for LG&E and $1.7 billion for KU) were available for payment of dividends to LKE. LG&E and KU believe they will not be required to change their current dividend practices as a result of the foregoing requirement. In addition, under Virginia law, KU is prohibited from making loans to affiliates without the prior approval of the VSCC. There are no comparable statutes under Kentucky law applicable to LG&E and KU, or under Pennsylvania law applicable to PPL Electric. However, orders from the KPSC require LG&E and KU to obtain prior consent or approval before lending amounts to PPL.

Acquisitions, Development and D

Acquisitions, Development and Divestitures	12 Months Ended
	Dec. 31, 2017
Acquisitions Development And Divestitures [Abstract]
Acquisitions, Development and Divestitures	8. Acquisitions, Development and Divestitures (All Registrants) The Registrants from time to time evaluate opportunities for potential acquisitions, divestitures and development projects. Development projects are reexamined based on market conditions and other factors to determine whether to proceed with, modify or terminate the projects. Any resulting transactions may impact future financial results. (PPL) Discontinued Operations Spinoff of PPL Energy Supply In June 2014, PPL and PPL Energy Supply executed definitive agreements with affiliates of Riverstone to spin off PPL Energy Supply and immediately combine it with Riverstone's competitive power generation businesses to form a new, stand-alone, publicly traded company named Talen Energy. The transaction was subject to customary closing conditions, including receipt of regulatory approvals from the NRC, FERC, DOJ and PUC, all of which were received by mid-April 2015. On April 29, 2015, PPL's Board of Directors declared the June 1, 2015 distribution to PPL's shareowners of record on May 20, 2015 of a newly formed entity, Holdco, which at closing owned all of the membership interests of PPL Energy Supply and all of the common stock of Talen Energy. Immediately following the spinoff on June 1, 2015, Holdco merged with a special purpose subsidiary of Talen Energy, with Holdco continuing as the surviving company to the merger and as a wholly owned subsidiary of Talen Energy and the sole owner of PPL Energy Supply. Substantially contemporaneous with the spinoff and merger, RJS Power was contributed by its owners to become a subsidiary of Talen Energy. PPL shareowners received approximately 0.1249 shares of Talen Energy common stock for each share of PPL common stock they owned on May 20, 2015. Following completion of these transactions, PPL shareowners owned 65% of Talen Energy and affiliates of Riverstone owned 35% . The spinoff had no effect on the number of PPL common shares owned by PPL shareowners or the number of shares of PPL common stock outstanding. The transaction is intended to be tax-free to PPL and its shareowners for U.S. federal income tax purposes. PPL has no continuing ownership interest in or control of Talen Energy and Talen Energy Supply (formerly PPL Energy Supply). Loss on Spinoff In June 2015, in conjunction with the accounting for the spinoff, PPL evaluated whether the fair value of the Supply segment's net assets was less than the carrying value as of the June 1, 2015 spinoff date. PPL considered several valuation methodologies to derive a fair value estimate of its Supply segment at the spinoff date. These methodologies included considering the closing "when-issued" Talen Energy market value on June 1, 2015 (the spinoff date), adjusted for the proportional share of the equity value attributable to the Supply segment, as well as, the valuation methods consistently used in PPL's quantitative goodwill impairment assessments - an income approach using a discounted cash flow analysis of the Supply segment and an alternative market approach considering market multiples of comparable companies. Although the Talen Energy market value approach utilized the most observable inputs of the three approaches, PPL considered certain limitations of the "when-issued" trading market for the spinoff transaction including the short trading duration, lack of liquidity in the market and anticipated initial Talen Energy stock ownership base selling pressure, among other factors, and concluded that these factors limited this input being solely determinative of the fair value of the Supply segment. As such, PPL also considered the other valuation approaches in estimating the overall fair value, but ultimately assigned the highest weighting to the Talen Energy market value approach. The following table summarizes PPL's fair value analysis: Approach Weighting Weighted Fair Value (in billions) Talen Energy Market Value 50% $ 1.4 Income/Discounted Cash Flow 30% 1.1 Alternative Market (Comparable Company) 20% 0.7 Estimated Fair Value $ 3.2 A key assumption included in the fair value estimate is the application of a control premium of 25% in the two market approaches. PPL concluded it was appropriate to apply a control premium in these approaches as the goodwill impairment testing guidance was followed in determining the estimated fair value of the Supply segment, which had historically been a reporting unit for PPL. This guidance provides that the market price of an individual security (and thus the market capitalization of a reporting unit with publicly traded equity securities) may not be representative of the fair value of the reporting unit. This guidance also indicates that substantial value may arise to a controlling shareholder from the ability to take advantage of synergies and other benefits that arise from control over another entity, and that the market price of a company's individual share of stock does not reflect this additional value to a controlling shareholder. Therefore, the quoted market price need not be the sole measurement basis for determining the fair value, and including a control premium is appropriate in measuring the fair value of a reporting unit. In determining the control premium, PPL reviewed premiums received during the prior five years in market sales transactions obtained from observable independent power producer and hybrid utility transactions greater than $1 billion . Premiums for these transactions ranged from 5% to 42% with a median of approximately 25% . Given these metrics, PPL concluded a control premium of 25% to be reasonable for both of the market valuation approaches used. Assumptions used in the discounted cash flow analysis included forward energy prices, forecasted generation, and forecasted operation and maintenance expenditures that were consistent with assumptions used in the Energy Supply portion of the Talen Energy business planning process at that time and a market participant discount rate. Using these methodologies and weightings, PPL determined the estimated fair value of the Supply segment (classified as Level 3) was below its carrying value of $4.1 billion and recorded a loss on the spinoff of $879 million in the second quarter of 2015, which is reflected in discontinued operations and is nondeductible for tax purposes. This amount served to reduce the basis of the net assets accounted for as a dividend at the June 1, 2015 spinoff date. Costs of Spinoff Following the announcement of the transaction to form Talen Energy, efforts were initiated to identify the appropriate staffing for Talen Energy and for PPL and its subsidiaries following completion of the spinoff. Organizational plans were substantially completed and estimated charges for employee separation benefits were recorded in 2014. In 2015, the organizational structures were finalized for both PPL and Talen Energy, which resulted in an additional charge of $10 million for employee separation benefits. Of this amount, $2 million related to Energy Supply positions and is reflected in discontinued operations. The remaining $8 million is reflected in "Other operation and maintenance" on the 2015 PPL Consolidated Statement of Income. The separation benefits include cash severance compensation, lump sum COBRA reimbursement payments and outplacement services. Additional employee-related costs incurred primarily included accelerated stock-based compensation and prorated performance-based cash incentive and stock-based compensation awards, primarily for PPL Energy Supply employees and for PPL Services employees who became PPL Energy Supply employees in connection with the transaction. PPL Energy Supply recognized $24 million of these costs at the spinoff closing date in 2015, which are reflected in discontinued operations. PPL recorded $45 million of third-party costs related to this transaction in 2015. Of these costs, $32 million were primarily for bank advisory, legal and accounting fees to facilitate the transaction, and are reflected in discontinued operations. An additional $13 million of consulting and other costs were incurred in 2015, related to the formation of the Talen Energy organization and to reconfigure the remaining PPL service functions. These costs are recorded primarily in "Other operation and maintenance" on the 2015 Statement of Income. At the close of the transaction in 2015, $72 million ( $42 million after-tax) of cash flow hedges, primarily unamortized losses on PPL interest rate swaps recorded in AOCI and designated as cash flow hedges of PPL Energy Supply's future interest payments, were reclassified into earnings and reflected in discontinued operations. Continuing Involvement (PPL and PPL Electric) As a result of the spinoff, PPL and PPL Energy Supply entered into a Transition Services Agreement (TSA) that terminated on May 31, 2017. The TSA set forth the terms and conditions for PPL and Talen Energy to provide certain transition services to one another. PPL provided Talen Energy certain information technology, financial and accounting, human resource and other specified services. PPL billed Talen Energy $1 million , $35 million and $25 million for these services in 2017 , 2016 and 2015. In general, the fees for the transition services allow the provider to recover its cost of the services, including overheads, but without margin or profit. Additionally, prior to the spinoff, through the annual competitive solicitation process, PPL EnergyPlus was awarded supply contracts for a portion of the PLR generation supply for PPL Electric, which were retained by Talen Energy Marketing as part of the spinoff transaction. PPL Electric's supply contracts with Talen Energy Marketing extended through November 2016. Energy purchases from PPL EnergyPlus were previously included in PPL Electric's Statements of Income as "Energy purchases from affiliate" but were eliminated in PPL's Consolidated Statements of Income. Subsequent to the spinoff, PPL Electric's energy purchases from Talen Energy Marketing were $106 million and $27 million for 2016 and 2015. There were no energy purchases from Talen Energy Marketing in 2017. These energy purchases are no longer considered affiliate transactions. (PPL) Summarized Results of Discontinued Operations The operations of the Supply segment are included in "Loss from Discontinued Operations (net of income taxes)" on the Statement of Income. Following are the components of Discontinued Operations in the Statement of Income for the period ended December 31: 2015 Operating revenues $ 1,427 Operating expenses 1,328 Other Income (Expense) - net (21 ) Interest expense (a) 150 Income tax expense (benefit) (30 ) Loss on spinoff (879 ) Loss from Discontinued Operations (net of income taxes) $ (921 ) (a) Includes interest associated with the Supply segment with no additional allocation as the Supply segment was sufficiently capitalized. Net assets, after recognition of the loss on the spinoff, of $3.2 billion were distributed to PPL shareowners in the June 1, 2015, spinoff of PPL Energy Supply. Development Regional Transmission Line Expansion Plan (PPL and PPL Electric) Northeast/Pocono In October 2012, the FERC issued an order in response to PPL Electric's December 2011 request for ratemaking incentives for the Northeast/Pocono Reliability project (a new 58 -mile, 230 kV transmission line that includes three new substations and upgrades to adjacent facilities). The FERC granted the incentive for inclusion in rate base of all prudently incurred construction work in progress costs but denied the requested incentive for a 100 basis point adder to the return on equity. In December 2012, PPL Electric submitted an application to the PUC requesting permission to site and construct the project. In January 2014, the PUC issued a final order approving the application. The line was energized in April 2016, completing the approximately $350 million project, which includes additional substation security enhancements. Costs related to the project are included on the Balance Sheets, primarily in "Regulated utility plant." Capacity Needs (PPL, LKE, LG&E and KU) As a result of environmental requirements and energy efficiency measures, KU anticipates retiring two older coal-fired electricity generating units at the E.W. Brown plant in 2019 with a combined summer rating capacity of 272 MW. The Cane Run Unit 7 NGCC was put into commercial operation in June 2015. As a result and to meet more stringent EPA regulations, LG&E retired one coal-fired generating unit at the Cane Run plant in March 2015 and retired the remaining two coal-fired generating units at the plant in June 2015. KU retired the two remaining coal-fired generating units at the Green River plant in September 2015. LG&E and KU incurred costs of $11 million and $6 million directly related to these retirements including inventory write-downs and separation benefits. There were no gains or losses on the retirement of these units. In December 2014, a final order was issued by the KPSC approving the request to construct a solar generation facility at the E.W. Brown facility. LG&E and KU completed construction activities and placed a 10 MW facility into commercial operation in June 2016 at a cost of $25 million .

Leases

Leases	12 Months Ended
	Dec. 31, 2017
Leases [Line Items]
Leases	9. Leases (PPL, LKE, LG&E and KU) PPL and its subsidiaries have entered into various agreements for the lease of office space, vehicles, land, gas storage and other equipment. Rent - Operating Leases Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11 Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41
LG And E And KU Energy LLC [Member]
Leases [Line Items]
Leases	9. Leases (PPL, LKE, LG&E and KU) PPL and its subsidiaries have entered into various agreements for the lease of office space, vehicles, land, gas storage and other equipment. Rent - Operating Leases Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11 Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41
Louisville Gas And Electric Co [Member]
Leases [Line Items]
Leases	9. Leases (PPL, LKE, LG&E and KU) PPL and its subsidiaries have entered into various agreements for the lease of office space, vehicles, land, gas storage and other equipment. Rent - Operating Leases Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11 Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41
Kentucky Utilities Co [Member]
Leases [Line Items]
Leases	9. Leases (PPL, LKE, LG&E and KU) PPL and its subsidiaries have entered into various agreements for the lease of office space, vehicles, land, gas storage and other equipment. Rent - Operating Leases Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11 Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2017
Stock-Based Compensation [Line Items]
Stock-Based Compensation	10. Stock-Based Compensation (PPL, PPL Electric and LKE) Under the ICP, SIP and the ICPKE (together, the Plans), restricted shares of PPL common stock, restricted stock units, performance units and stock options may be granted to officers and other key employees of PPL, PPL Electric, LKE and other affiliated companies. Awards under the Plans are made by the Compensation, Governance and Nominating Committee (CGNC) of the PPL Board of Directors, in the case of the ICP and SIP, and by the PPL Corporate Leadership Council (CLC), in the case of the ICPKE. The following table details the award limits under each of the Plans. Total Plan Annual Grant Limit Total As % of Outstanding Annual Grant Annual Grant Limit For Individual Participants - Performance Based Awards Award Limit PPL Common Stock On First Day of Limit Options For awards denominated in For awards denominated in Plan (Shares) Each Calendar Year (Shares) shares (Shares) cash (in dollars) SIP 15,000,000 2,000,000 750,000 $ 15,000,000 ICPKE 14,199,796 2 % 3,000,000 Any portion of these awards that has not been granted may be carried over and used in any subsequent year. If any award lapses, is forfeited or the rights of the participant terminate, the shares of PPL common stock underlying such an award are again available for grant. Shares delivered under the Plans may be in the form of authorized and unissued PPL common stock, common stock held in treasury by PPL or PPL common stock purchased on the open market (including private purchases) in accordance with applicable securities laws. Restricted Stock Units Restricted stock units are awards based on the fair value of PPL common stock on the date of grant. Actual PPL common shares will be issued upon completion of a restriction period, generally three years. Under the SIP, each restricted stock unit entitles the executive to accrue additional restricted stock units equal to the amount of quarterly dividends paid on PPL stock. These additional restricted stock units are deferred and payable in shares of PPL common stock at the end of the restriction period. Dividend equivalents on restricted stock unit awards granted under the ICPKE are currently paid in cash when dividends are declared by PPL. The fair value of restricted stock units granted is recognized on a straight-line basis over the service period or through the date at which the employee reaches retirement eligibility. The fair value of restricted stock units granted to retirement-eligible employees is recognized as compensation expense immediately upon the date of grant. Recipients of restricted stock units granted under the ICPKE may also be granted the right to receive dividend equivalents through the end of the restriction period or until the award is forfeited. Restricted stock units are subject to forfeiture or accelerated payout under the plan provisions for termination, retirement, disability and death of employees. Restrictions lapse on restricted stock units fully, in certain situations, as defined by each of the Plans. The weighted-average grant date fair value of restricted stock units granted was: 2017 2016 2015 PPL $ 35.30 $ 33.84 $ 34.50 PPL Electric 35.45 34.32 34.41 LKE 35.25 33.73 34.89 Restricted stock unit activity for 2017 was: Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,337,025 $ 31.57 Granted 538,441 35.30 Vested (567,001 ) 29.28 Forfeited (16,816 ) 34.28 Nonvested, end of period (a) 1,291,649 34.10 Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Electric Nonvested, beginning of period 204,570 $ 31.27 Transfer between registrants (5,250 ) 32.05 Granted 79,321 35.45 Vested (91,117 ) 28.83 Forfeited (3,108 ) 34.68 Nonvested, end of period 184,416 34.20 LKE Nonvested, beginning of period 243,281 $ 31.53 Transfer between registrants 25,337 31.61 Granted 97,775 35.25 Vested (125,612 ) 29.68 Forfeited (9,224 ) 34.04 Nonvested, end of period 231,557 34.01 (a) Excludes 252,850 restricted stock units for which restrictions lapsed for former PPL Energy Supply employees as a result of the spinoff, but for which distribution will not occur until the end of the original restriction period of the awards. Substantially all restricted stock unit awards are expected to vest. The total fair value of restricted stock units vesting for the years ended December 31 was: 2017 2016 2015 PPL $ 20 $ 30 $ 28 PPL Electric 3 3 4 LKE 4 5 4 Performance Units - Total Shareowner Return Performance units based on Total Shareowner Return (TSR) are intended to encourage and reward future corporate performance. Performance units represent a target number of shares (Target Award) of PPL's common stock that the recipient would receive upon PPL's attainment of the applicable performance goal. Performance is determined based on TSR during a three -year performance period. At the end of the period, payout is determined by comparing PPL's performance to the TSR of the companies included in the Philadelphia Stock Exchange Utility Index. Awards are payable on a graduated basis based on thresholds that measure PPL's performance relative to peers that comprise the applicable index on which each years' awards are measured. Awards can be paid up to 200% of the Target Award or forfeited with no payout if performance is below a minimum established performance threshold. Dividends payable during the performance cycle accumulate and are converted into additional performance units and are payable in shares of PPL common stock upon completion of the performance period based on the determination of the CGNC of whether the performance goals have been achieved. Under the plan provisions, TSR performance units are subject to forfeiture upon termination of employment except for retirement, one year or more from commencement of the performance period, disability or death of an employee. The fair value of TSR performance units granted to retirement-eligible employees is recognized as compensation expense on a straight-line basis over a one -year period, the minimum vesting period required for an employee to be entitled to payout of the awards with no proration. For employees who are not retirement-eligible, compensation expense is recognized over the shorter of the three -year performance period or the period until the employee is retirement-eligible, with a minimum vesting and recognition period of one -year. If an employee retires before the one -year vesting period, the performance units are forfeited. Performance units vest on a pro rata basis, in certain situations, as defined by each of the Plans. The fair value of each performance unit granted was estimated using a Monte Carlo pricing model that considers stock beta, a risk-free interest rate, expected stock volatility and expected life. The stock beta was calculated comparing the risk of the individual securities to the average risk of the companies in the index group. The risk-free interest rate reflects the yield on a U.S. Treasury bond commensurate with the expected life of the performance unit. Volatility over the expected term of the performance unit is calculated using daily stock price observations for PPL and all companies in the index group and is evaluated with consideration given to prior periods that may need to be excluded based on events not likely to recur that had impacted PPL and the companies in the index group. PPL uses a mix of historic and implied volatility to value awards. The weighted-average assumptions used in the model were: 2017 2016 2015 Expected stock volatility 17.40 % 19.60 % 15.90 % Expected life 3 years 3 years 3 years The weighted-average grant date fair value of TSR performance units granted was: 2017 2016 2015 PPL $ 38.38 $ 35.74 $ 36.76 PPL Electric 38.37 35.68 37.93 LKE 38.24 35.28 37.10 TSR performance unit activity for 2017 was: TSR Performance Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,070,536 $ 34.65 Granted 293,642 38.38 Vested (243,983 ) 32.42 Forfeited (141,964 ) 32.27 Nonvested, end of period (a) 978,231 36.67 PPL Electric Nonvested, beginning of period 76,726 $ 34.68 Granted 26,086 38.37 Vested (14,713 ) 32.14 Forfeited (12,586 ) 35.45 Nonvested, end of period 75,513 37.00 LKE Nonvested, beginning of period 191,601 $ 34.34 Transfer between registrants 8,307 35.96 Granted 64,555 38.24 Vested (48,980 ) 32.09 Forfeited (35,194 ) 35.25 Nonvested, end of period 180,289 36.69 (a) Excludes 41,405 TSR awards for which the service vesting requirement was waived for former PPL Energy Supply employees as a result of the spinoff, but for which the ultimate number of shares to be distributed will depend on the actual attainment of the performance goals at the end of the specified performance periods. The total fair value of TSR performance units vesting for the year ended December 31, 2017 , 2016 and 2015 was $8 million , $12 million and $6 million for PPL and insignificant for PPL Electric and LKE. Performance Units - Return on Equity Beginning in 2017, PPL changed its executive compensation mix to add performance units based on achievement of a corporate Return on Equity (ROE). ROE performance units are intended to further align compensation with the company’s strategy and reward for future corporate performance. Payout of these performance units will be based on the calculated average of the annual corporate ROE for each year of the three -year performance period for PPL Corporation. ROE performance units represent a target number of shares (Target Award) of PPL's common stock that the recipient would receive upon PPL's attainment of the applicable ROE performance goal. ROE performance units can be paid up to 200% of the Target Award or forfeited with no payout if performance is below a minimum established performance threshold. Dividends payable during the performance cycle accumulate and are converted into additional performance units and are payable in shares of PPL common stock upon completion of the performance period based on the determination of the CGNC of whether the performance goals have been achieved. Under the plan provisions, these performance units are subject to forfeiture upon termination of employment except for retirement, disability or death of an employee. The fair value of each ROE performance unit is based on the closing price of PPL Common Stock on the date of grant. The fair value of ROE performance units is recognized on a straight-line basis over the service period or through the date at which the employee reaches retirement eligibility. The fair value awards granted to retirement-eligible employees is recognized as compensation expense immediately upon the date of grant. As these awards are based on performance conditions, the level of attainment is monitored each reporting period and compensation expense is adjusted based on the expected attainment level. ROE performance unit activity for 2017 was: ROE Performance Unit Weighted- Average Grant Date Fair Value Per Share PPL Granted 97,925 $ 34.42 Forfeited (997 ) 34.41 Nonvested, end of period 96,928 34.42 PPL Electric Granted 8,696 $ 34.41 Nonvested, end of period 8,696 34.41 LKE Granted 21,536 $ 34.29 Forfeited (997 ) 34.41 Nonvested, end of period 20,539 34.29 Stock Options PPL's CGNC eliminated the use of stock options due to changes in its long-term incentive mix beginning in January 2014 . Under the Plans, stock options had been granted with an option exercise price per share not less than the fair value of PPL's common stock on the date of grant. Options outstanding at December 31, 2017 , are fully vested. All options expire no later than 10 years from the grant date. The options become exercisable immediately in certain situations, as defined by each of the Plans. Stock option activity for 2017 was: Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value PPL Outstanding at beginning of period 4,481,160 $ 28.98 Exercised (718,977 ) 26.67 Outstanding and exercisable at end of period 3,762,183 29.42 3.5 $ 14 PPL Electric Outstanding at beginning of period 240,939 $ 27.48 Exercised (42,659 ) 26.99 Outstanding and exercisable at end of period 198,280 27.58 3.8 $ 1 Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value LKE Outstanding at beginning of period 61,896 $ 25.81 Exercised (28,164 ) 26.59 Outstanding and exercisable at end of period 33,732 25.15 4.1 $ — For 2017 , 2016 and 2015 , PPL received $19 million , $52 million and $97 million in cash from stock options exercised. The related income tax benefits realized were not significant. The total intrinsic value of stock options exercised for 2017 , 2016 and 2015 were $8 million , $18 million and $21 million . Compensation Expense Compensation expense for restricted stock, restricted stock units, performance units and stock options accounted for as equity awards, which for PPL Electric and LKE includes an allocation of PPL Services' expense, was: 2017 2016 2015 PPL $ 32 $ 27 $ 33 PPL Electric 18 16 14 LKE 8 7 8 See Note 8 for details of the costs recognized in discontinued operations related to the accelerated vesting of awards for former PPL Energy Supply employees. The income tax benefit related to above compensation expense was as follows: 2017 2016 2015 PPL $ 13 $ 12 $ 14 PPL Electric 8 7 6 LKE 3 3 3 At December 31, 2017 , unrecognized compensation expense related to nonvested stock awards was: Unrecognized Compensation Expense Weighted- Average Period for Recognition PPL $ 10 1.7 PPL Electric 2 1.7 LKE 1 1.6
PPL Electric Utilities Corp [Member]
Stock-Based Compensation [Line Items]
Stock-Based Compensation	10. Stock-Based Compensation (PPL, PPL Electric and LKE) Under the ICP, SIP and the ICPKE (together, the Plans), restricted shares of PPL common stock, restricted stock units, performance units and stock options may be granted to officers and other key employees of PPL, PPL Electric, LKE and other affiliated companies. Awards under the Plans are made by the Compensation, Governance and Nominating Committee (CGNC) of the PPL Board of Directors, in the case of the ICP and SIP, and by the PPL Corporate Leadership Council (CLC), in the case of the ICPKE. The following table details the award limits under each of the Plans. Total Plan Annual Grant Limit Total As % of Outstanding Annual Grant Annual Grant Limit For Individual Participants - Performance Based Awards Award Limit PPL Common Stock On First Day of Limit Options For awards denominated in For awards denominated in Plan (Shares) Each Calendar Year (Shares) shares (Shares) cash (in dollars) SIP 15,000,000 2,000,000 750,000 $ 15,000,000 ICPKE 14,199,796 2 % 3,000,000 Any portion of these awards that has not been granted may be carried over and used in any subsequent year. If any award lapses, is forfeited or the rights of the participant terminate, the shares of PPL common stock underlying such an award are again available for grant. Shares delivered under the Plans may be in the form of authorized and unissued PPL common stock, common stock held in treasury by PPL or PPL common stock purchased on the open market (including private purchases) in accordance with applicable securities laws. Restricted Stock Units Restricted stock units are awards based on the fair value of PPL common stock on the date of grant. Actual PPL common shares will be issued upon completion of a restriction period, generally three years. Under the SIP, each restricted stock unit entitles the executive to accrue additional restricted stock units equal to the amount of quarterly dividends paid on PPL stock. These additional restricted stock units are deferred and payable in shares of PPL common stock at the end of the restriction period. Dividend equivalents on restricted stock unit awards granted under the ICPKE are currently paid in cash when dividends are declared by PPL. The fair value of restricted stock units granted is recognized on a straight-line basis over the service period or through the date at which the employee reaches retirement eligibility. The fair value of restricted stock units granted to retirement-eligible employees is recognized as compensation expense immediately upon the date of grant. Recipients of restricted stock units granted under the ICPKE may also be granted the right to receive dividend equivalents through the end of the restriction period or until the award is forfeited. Restricted stock units are subject to forfeiture or accelerated payout under the plan provisions for termination, retirement, disability and death of employees. Restrictions lapse on restricted stock units fully, in certain situations, as defined by each of the Plans. The weighted-average grant date fair value of restricted stock units granted was: 2017 2016 2015 PPL $ 35.30 $ 33.84 $ 34.50 PPL Electric 35.45 34.32 34.41 LKE 35.25 33.73 34.89 Restricted stock unit activity for 2017 was: Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,337,025 $ 31.57 Granted 538,441 35.30 Vested (567,001 ) 29.28 Forfeited (16,816 ) 34.28 Nonvested, end of period (a) 1,291,649 34.10 Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Electric Nonvested, beginning of period 204,570 $ 31.27 Transfer between registrants (5,250 ) 32.05 Granted 79,321 35.45 Vested (91,117 ) 28.83 Forfeited (3,108 ) 34.68 Nonvested, end of period 184,416 34.20 LKE Nonvested, beginning of period 243,281 $ 31.53 Transfer between registrants 25,337 31.61 Granted 97,775 35.25 Vested (125,612 ) 29.68 Forfeited (9,224 ) 34.04 Nonvested, end of period 231,557 34.01 (a) Excludes 252,850 restricted stock units for which restrictions lapsed for former PPL Energy Supply employees as a result of the spinoff, but for which distribution will not occur until the end of the original restriction period of the awards. Substantially all restricted stock unit awards are expected to vest. The total fair value of restricted stock units vesting for the years ended December 31 was: 2017 2016 2015 PPL $ 20 $ 30 $ 28 PPL Electric 3 3 4 LKE 4 5 4 Performance Units - Total Shareowner Return Performance units based on Total Shareowner Return (TSR) are intended to encourage and reward future corporate performance. Performance units represent a target number of shares (Target Award) of PPL's common stock that the recipient would receive upon PPL's attainment of the applicable performance goal. Performance is determined based on TSR during a three -year performance period. At the end of the period, payout is determined by comparing PPL's performance to the TSR of the companies included in the Philadelphia Stock Exchange Utility Index. Awards are payable on a graduated basis based on thresholds that measure PPL's performance relative to peers that comprise the applicable index on which each years' awards are measured. Awards can be paid up to 200% of the Target Award or forfeited with no payout if performance is below a minimum established performance threshold. Dividends payable during the performance cycle accumulate and are converted into additional performance units and are payable in shares of PPL common stock upon completion of the performance period based on the determination of the CGNC of whether the performance goals have been achieved. Under the plan provisions, TSR performance units are subject to forfeiture upon termination of employment except for retirement, one year or more from commencement of the performance period, disability or death of an employee. The fair value of TSR performance units granted to retirement-eligible employees is recognized as compensation expense on a straight-line basis over a one -year period, the minimum vesting period required for an employee to be entitled to payout of the awards with no proration. For employees who are not retirement-eligible, compensation expense is recognized over the shorter of the three -year performance period or the period until the employee is retirement-eligible, with a minimum vesting and recognition period of one -year. If an employee retires before the one -year vesting period, the performance units are forfeited. Performance units vest on a pro rata basis, in certain situations, as defined by each of the Plans. The fair value of each performance unit granted was estimated using a Monte Carlo pricing model that considers stock beta, a risk-free interest rate, expected stock volatility and expected life. The stock beta was calculated comparing the risk of the individual securities to the average risk of the companies in the index group. The risk-free interest rate reflects the yield on a U.S. Treasury bond commensurate with the expected life of the performance unit. Volatility over the expected term of the performance unit is calculated using daily stock price observations for PPL and all companies in the index group and is evaluated with consideration given to prior periods that may need to be excluded based on events not likely to recur that had impacted PPL and the companies in the index group. PPL uses a mix of historic and implied volatility to value awards. The weighted-average assumptions used in the model were: 2017 2016 2015 Expected stock volatility 17.40 % 19.60 % 15.90 % Expected life 3 years 3 years 3 years The weighted-average grant date fair value of TSR performance units granted was: 2017 2016 2015 PPL $ 38.38 $ 35.74 $ 36.76 PPL Electric 38.37 35.68 37.93 LKE 38.24 35.28 37.10 TSR performance unit activity for 2017 was: TSR Performance Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,070,536 $ 34.65 Granted 293,642 38.38 Vested (243,983 ) 32.42 Forfeited (141,964 ) 32.27 Nonvested, end of period (a) 978,231 36.67 PPL Electric Nonvested, beginning of period 76,726 $ 34.68 Granted 26,086 38.37 Vested (14,713 ) 32.14 Forfeited (12,586 ) 35.45 Nonvested, end of period 75,513 37.00 LKE Nonvested, beginning of period 191,601 $ 34.34 Transfer between registrants 8,307 35.96 Granted 64,555 38.24 Vested (48,980 ) 32.09 Forfeited (35,194 ) 35.25 Nonvested, end of period 180,289 36.69 (a) Excludes 41,405 TSR awards for which the service vesting requirement was waived for former PPL Energy Supply employees as a result of the spinoff, but for which the ultimate number of shares to be distributed will depend on the actual attainment of the performance goals at the end of the specified performance periods. The total fair value of TSR performance units vesting for the year ended December 31, 2017 , 2016 and 2015 was $8 million , $12 million and $6 million for PPL and insignificant for PPL Electric and LKE. Performance Units - Return on Equity Beginning in 2017, PPL changed its executive compensation mix to add performance units based on achievement of a corporate Return on Equity (ROE). ROE performance units are intended to further align compensation with the company’s strategy and reward for future corporate performance. Payout of these performance units will be based on the calculated average of the annual corporate ROE for each year of the three -year performance period for PPL Corporation. ROE performance units represent a target number of shares (Target Award) of PPL's common stock that the recipient would receive upon PPL's attainment of the applicable ROE performance goal. ROE performance units can be paid up to 200% of the Target Award or forfeited with no payout if performance is below a minimum established performance threshold. Dividends payable during the performance cycle accumulate and are converted into additional performance units and are payable in shares of PPL common stock upon completion of the performance period based on the determination of the CGNC of whether the performance goals have been achieved. Under the plan provisions, these performance units are subject to forfeiture upon termination of employment except for retirement, disability or death of an employee. The fair value of each ROE performance unit is based on the closing price of PPL Common Stock on the date of grant. The fair value of ROE performance units is recognized on a straight-line basis over the service period or through the date at which the employee reaches retirement eligibility. The fair value awards granted to retirement-eligible employees is recognized as compensation expense immediately upon the date of grant. As these awards are based on performance conditions, the level of attainment is monitored each reporting period and compensation expense is adjusted based on the expected attainment level. ROE performance unit activity for 2017 was: ROE Performance Unit Weighted- Average Grant Date Fair Value Per Share PPL Granted 97,925 $ 34.42 Forfeited (997 ) 34.41 Nonvested, end of period 96,928 34.42 PPL Electric Granted 8,696 $ 34.41 Nonvested, end of period 8,696 34.41 LKE Granted 21,536 $ 34.29 Forfeited (997 ) 34.41 Nonvested, end of period 20,539 34.29 Stock Options PPL's CGNC eliminated the use of stock options due to changes in its long-term incentive mix beginning in January 2014 . Under the Plans, stock options had been granted with an option exercise price per share not less than the fair value of PPL's common stock on the date of grant. Options outstanding at December 31, 2017 , are fully vested. All options expire no later than 10 years from the grant date. The options become exercisable immediately in certain situations, as defined by each of the Plans. Stock option activity for 2017 was: Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value PPL Outstanding at beginning of period 4,481,160 $ 28.98 Exercised (718,977 ) 26.67 Outstanding and exercisable at end of period 3,762,183 29.42 3.5 $ 14 PPL Electric Outstanding at beginning of period 240,939 $ 27.48 Exercised (42,659 ) 26.99 Outstanding and exercisable at end of period 198,280 27.58 3.8 $ 1 Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value LKE Outstanding at beginning of period 61,896 $ 25.81 Exercised (28,164 ) 26.59 Outstanding and exercisable at end of period 33,732 25.15 4.1 $ — For 2017 , 2016 and 2015 , PPL received $19 million , $52 million and $97 million in cash from stock options exercised. The related income tax benefits realized were not significant. The total intrinsic value of stock options exercised for 2017 , 2016 and 2015 were $8 million , $18 million and $21 million . Compensation Expense Compensation expense for restricted stock, restricted stock units, performance units and stock options accounted for as equity awards, which for PPL Electric and LKE includes an allocation of PPL Services' expense, was: 2017 2016 2015 PPL $ 32 $ 27 $ 33 PPL Electric 18 16 14 LKE 8 7 8 See Note 8 for details of the costs recognized in discontinued operations related to the accelerated vesting of awards for former PPL Energy Supply employees. The income tax benefit related to above compensation expense was as follows: 2017 2016 2015 PPL $ 13 $ 12 $ 14 PPL Electric 8 7 6 LKE 3 3 3 At December 31, 2017 , unrecognized compensation expense related to nonvested stock awards was: Unrecognized Compensation Expense Weighted- Average Period for Recognition PPL $ 10 1.7 PPL Electric 2 1.7 LKE 1 1.6
LG And E And KU Energy LLC [Member]
Stock-Based Compensation [Line Items]
Stock-Based Compensation	10. Stock-Based Compensation (PPL, PPL Electric and LKE) Under the ICP, SIP and the ICPKE (together, the Plans), restricted shares of PPL common stock, restricted stock units, performance units and stock options may be granted to officers and other key employees of PPL, PPL Electric, LKE and other affiliated companies. Awards under the Plans are made by the Compensation, Governance and Nominating Committee (CGNC) of the PPL Board of Directors, in the case of the ICP and SIP, and by the PPL Corporate Leadership Council (CLC), in the case of the ICPKE. The following table details the award limits under each of the Plans. Total Plan Annual Grant Limit Total As % of Outstanding Annual Grant Annual Grant Limit For Individual Participants - Performance Based Awards Award Limit PPL Common Stock On First Day of Limit Options For awards denominated in For awards denominated in Plan (Shares) Each Calendar Year (Shares) shares (Shares) cash (in dollars) SIP 15,000,000 2,000,000 750,000 $ 15,000,000 ICPKE 14,199,796 2 % 3,000,000 Any portion of these awards that has not been granted may be carried over and used in any subsequent year. If any award lapses, is forfeited or the rights of the participant terminate, the shares of PPL common stock underlying such an award are again available for grant. Shares delivered under the Plans may be in the form of authorized and unissued PPL common stock, common stock held in treasury by PPL or PPL common stock purchased on the open market (including private purchases) in accordance with applicable securities laws. Restricted Stock Units Restricted stock units are awards based on the fair value of PPL common stock on the date of grant. Actual PPL common shares will be issued upon completion of a restriction period, generally three years. Under the SIP, each restricted stock unit entitles the executive to accrue additional restricted stock units equal to the amount of quarterly dividends paid on PPL stock. These additional restricted stock units are deferred and payable in shares of PPL common stock at the end of the restriction period. Dividend equivalents on restricted stock unit awards granted under the ICPKE are currently paid in cash when dividends are declared by PPL. The fair value of restricted stock units granted is recognized on a straight-line basis over the service period or through the date at which the employee reaches retirement eligibility. The fair value of restricted stock units granted to retirement-eligible employees is recognized as compensation expense immediately upon the date of grant. Recipients of restricted stock units granted under the ICPKE may also be granted the right to receive dividend equivalents through the end of the restriction period or until the award is forfeited. Restricted stock units are subject to forfeiture or accelerated payout under the plan provisions for termination, retirement, disability and death of employees. Restrictions lapse on restricted stock units fully, in certain situations, as defined by each of the Plans. The weighted-average grant date fair value of restricted stock units granted was: 2017 2016 2015 PPL $ 35.30 $ 33.84 $ 34.50 PPL Electric 35.45 34.32 34.41 LKE 35.25 33.73 34.89 Restricted stock unit activity for 2017 was: Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,337,025 $ 31.57 Granted 538,441 35.30 Vested (567,001 ) 29.28 Forfeited (16,816 ) 34.28 Nonvested, end of period (a) 1,291,649 34.10 Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Electric Nonvested, beginning of period 204,570 $ 31.27 Transfer between registrants (5,250 ) 32.05 Granted 79,321 35.45 Vested (91,117 ) 28.83 Forfeited (3,108 ) 34.68 Nonvested, end of period 184,416 34.20 LKE Nonvested, beginning of period 243,281 $ 31.53 Transfer between registrants 25,337 31.61 Granted 97,775 35.25 Vested (125,612 ) 29.68 Forfeited (9,224 ) 34.04 Nonvested, end of period 231,557 34.01 (a) Excludes 252,850 restricted stock units for which restrictions lapsed for former PPL Energy Supply employees as a result of the spinoff, but for which distribution will not occur until the end of the original restriction period of the awards. Substantially all restricted stock unit awards are expected to vest. The total fair value of restricted stock units vesting for the years ended December 31 was: 2017 2016 2015 PPL $ 20 $ 30 $ 28 PPL Electric 3 3 4 LKE 4 5 4 Performance Units - Total Shareowner Return Performance units based on Total Shareowner Return (TSR) are intended to encourage and reward future corporate performance. Performance units represent a target number of shares (Target Award) of PPL's common stock that the recipient would receive upon PPL's attainment of the applicable performance goal. Performance is determined based on TSR during a three -year performance period. At the end of the period, payout is determined by comparing PPL's performance to the TSR of the companies included in the Philadelphia Stock Exchange Utility Index. Awards are payable on a graduated basis based on thresholds that measure PPL's performance relative to peers that comprise the applicable index on which each years' awards are measured. Awards can be paid up to 200% of the Target Award or forfeited with no payout if performance is below a minimum established performance threshold. Dividends payable during the performance cycle accumulate and are converted into additional performance units and are payable in shares of PPL common stock upon completion of the performance period based on the determination of the CGNC of whether the performance goals have been achieved. Under the plan provisions, TSR performance units are subject to forfeiture upon termination of employment except for retirement, one year or more from commencement of the performance period, disability or death of an employee. The fair value of TSR performance units granted to retirement-eligible employees is recognized as compensation expense on a straight-line basis over a one -year period, the minimum vesting period required for an employee to be entitled to payout of the awards with no proration. For employees who are not retirement-eligible, compensation expense is recognized over the shorter of the three -year performance period or the period until the employee is retirement-eligible, with a minimum vesting and recognition period of one -year. If an employee retires before the one -year vesting period, the performance units are forfeited. Performance units vest on a pro rata basis, in certain situations, as defined by each of the Plans. The fair value of each performance unit granted was estimated using a Monte Carlo pricing model that considers stock beta, a risk-free interest rate, expected stock volatility and expected life. The stock beta was calculated comparing the risk of the individual securities to the average risk of the companies in the index group. The risk-free interest rate reflects the yield on a U.S. Treasury bond commensurate with the expected life of the performance unit. Volatility over the expected term of the performance unit is calculated using daily stock price observations for PPL and all companies in the index group and is evaluated with consideration given to prior periods that may need to be excluded based on events not likely to recur that had impacted PPL and the companies in the index group. PPL uses a mix of historic and implied volatility to value awards. The weighted-average assumptions used in the model were: 2017 2016 2015 Expected stock volatility 17.40 % 19.60 % 15.90 % Expected life 3 years 3 years 3 years The weighted-average grant date fair value of TSR performance units granted was: 2017 2016 2015 PPL $ 38.38 $ 35.74 $ 36.76 PPL Electric 38.37 35.68 37.93 LKE 38.24 35.28 37.10 TSR performance unit activity for 2017 was: TSR Performance Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,070,536 $ 34.65 Granted 293,642 38.38 Vested (243,983 ) 32.42 Forfeited (141,964 ) 32.27 Nonvested, end of period (a) 978,231 36.67 PPL Electric Nonvested, beginning of period 76,726 $ 34.68 Granted 26,086 38.37 Vested (14,713 ) 32.14 Forfeited (12,586 ) 35.45 Nonvested, end of period 75,513 37.00 LKE Nonvested, beginning of period 191,601 $ 34.34 Transfer between registrants 8,307 35.96 Granted 64,555 38.24 Vested (48,980 ) 32.09 Forfeited (35,194 ) 35.25 Nonvested, end of period 180,289 36.69 (a) Excludes 41,405 TSR awards for which the service vesting requirement was waived for former PPL Energy Supply employees as a result of the spinoff, but for which the ultimate number of shares to be distributed will depend on the actual attainment of the performance goals at the end of the specified performance periods. The total fair value of TSR performance units vesting for the year ended December 31, 2017 , 2016 and 2015 was $8 million , $12 million and $6 million for PPL and insignificant for PPL Electric and LKE. Performance Units - Return on Equity Beginning in 2017, PPL changed its executive compensation mix to add performance units based on achievement of a corporate Return on Equity (ROE). ROE performance units are intended to further align compensation with the company’s strategy and reward for future corporate performance. Payout of these performance units will be based on the calculated average of the annual corporate ROE for each year of the three -year performance period for PPL Corporation. ROE performance units represent a target number of shares (Target Award) of PPL's common stock that the recipient would receive upon PPL's attainment of the applicable ROE performance goal. ROE performance units can be paid up to 200% of the Target Award or forfeited with no payout if performance is below a minimum established performance threshold. Dividends payable during the performance cycle accumulate and are converted into additional performance units and are payable in shares of PPL common stock upon completion of the performance period based on the determination of the CGNC of whether the performance goals have been achieved. Under the plan provisions, these performance units are subject to forfeiture upon termination of employment except for retirement, disability or death of an employee. The fair value of each ROE performance unit is based on the closing price of PPL Common Stock on the date of grant. The fair value of ROE performance units is recognized on a straight-line basis over the service period or through the date at which the employee reaches retirement eligibility. The fair value awards granted to retirement-eligible employees is recognized as compensation expense immediately upon the date of grant. As these awards are based on performance conditions, the level of attainment is monitored each reporting period and compensation expense is adjusted based on the expected attainment level. ROE performance unit activity for 2017 was: ROE Performance Unit Weighted- Average Grant Date Fair Value Per Share PPL Granted 97,925 $ 34.42 Forfeited (997 ) 34.41 Nonvested, end of period 96,928 34.42 PPL Electric Granted 8,696 $ 34.41 Nonvested, end of period 8,696 34.41 LKE Granted 21,536 $ 34.29 Forfeited (997 ) 34.41 Nonvested, end of period 20,539 34.29 Stock Options PPL's CGNC eliminated the use of stock options due to changes in its long-term incentive mix beginning in January 2014 . Under the Plans, stock options had been granted with an option exercise price per share not less than the fair value of PPL's common stock on the date of grant. Options outstanding at December 31, 2017 , are fully vested. All options expire no later than 10 years from the grant date. The options become exercisable immediately in certain situations, as defined by each of the Plans. Stock option activity for 2017 was: Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value PPL Outstanding at beginning of period 4,481,160 $ 28.98 Exercised (718,977 ) 26.67 Outstanding and exercisable at end of period 3,762,183 29.42 3.5 $ 14 PPL Electric Outstanding at beginning of period 240,939 $ 27.48 Exercised (42,659 ) 26.99 Outstanding and exercisable at end of period 198,280 27.58 3.8 $ 1 Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value LKE Outstanding at beginning of period 61,896 $ 25.81 Exercised (28,164 ) 26.59 Outstanding and exercisable at end of period 33,732 25.15 4.1 $ — For 2017 , 2016 and 2015 , PPL received $19 million , $52 million and $97 million in cash from stock options exercised. The related income tax benefits realized were not significant. The total intrinsic value of stock options exercised for 2017 , 2016 and 2015 were $8 million , $18 million and $21 million . Compensation Expense Compensation expense for restricted stock, restricted stock units, performance units and stock options accounted for as equity awards, which for PPL Electric and LKE includes an allocation of PPL Services' expense, was: 2017 2016 2015 PPL $ 32 $ 27 $ 33 PPL Electric 18 16 14 LKE 8 7 8 See Note 8 for details of the costs recognized in discontinued operations related to the accelerated vesting of awards for former PPL Energy Supply employees. The income tax benefit related to above compensation expense was as follows: 2017 2016 2015 PPL $ 13 $ 12 $ 14 PPL Electric 8 7 6 LKE 3 3 3 At December 31, 2017 , unrecognized compensation expense related to nonvested stock awards was: Unrecognized Compensation Expense Weighted- Average Period for Recognition PPL $ 10 1.7 PPL Electric 2 1.7 LKE 1 1.6

Retirement and Postemployment B

Retirement and Postemployment Benefits	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Retirement and Postemployment Benefits	11. Retirement and Postemployment Benefits (All Registrants) Defined Benefits The majority of the employees of PPL's domestic subsidiaries are eligible for pension benefits under non-contributory defined benefit pension plans with benefits based on length of service and final average pay, as defined by the plans. Effective January 1, 2012, PPL's primary defined benefit pension plan was closed to all newly hired salaried employees. Effective July 1, 2014, PPL's primary defined benefit pension plan was closed to all newly hired bargaining unit employees. Newly hired employees are eligible to participate in the PPL Retirement Savings Plan, a 401(k) savings plan with enhanced employer contributions. The defined benefit pension plans of LKE and its subsidiaries were closed to new salaried and bargaining unit employees hired after December 31, 2005. Employees hired after December 31, 2005 receive additional company contributions above the standard matching contributions to their savings plans. Effective April 1, 2010, the principal defined benefit pension plan applicable to WPD (South West) and WPD (South Wales) was closed to most new employees, except for those meeting specific grandfathered participation rights. WPD Midlands' defined benefit plan had been closed to new members, except for those meeting specific grandfathered participation rights, prior to acquisition. New employees not eligible to participate in the plans are offered benefits under a defined contribution plan. PPL and certain of its subsidiaries also provide supplemental retirement benefits to executives and other key management employees through unfunded nonqualified retirement plans. The majority of employees of PPL's domestic subsidiaries are eligible for certain health care and life insurance benefits upon retirement through contributory plans. Effective January 1, 2014, the PPL Postretirement Medical Plan was closed to all newly hired salaried employees. Effective July 1, 2014, the PPL Postretirement Medical Plan was closed to all newly hired bargaining unit employees. Postretirement health benefits may be paid from 401(h) accounts established as part of the PPL Retirement Plan and the LG&E and KU Retirement Plan within the PPL Services Corporation Master Trust, funded VEBA trusts and company funds. WPD does not sponsor any postretirement benefit plans other than pensions. (PPL) The following table provides the components of net periodic defined benefit costs for PPL's domestic (U.S.) and WPD's (U.K.) pension and other postretirement benefit plans for the years ended December 31. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 Net periodic defined benefit costs (credits): Service cost $ 65 $ 66 $ 96 $ 76 $ 69 $ 79 $ 7 $ 7 $ 11 Interest cost 168 174 194 178 235 314 23 26 26 Expected return on plan assets (231 ) (228 ) (258 ) (514 ) (504 ) (523 ) (22 ) (22 ) (26 ) Amortization of: Prior service cost (credit) 10 8 7 — — — (1 ) — 1 Actuarial (gain) loss 69 50 84 144 138 158 1 1 — Net periodic defined benefit costs (credits) prior to settlements and termination benefits 81 70 123 (116 ) (62 ) 28 8 12 12 Settlements 1 3 — — — — — — — Termination benefits 1 — — — — — — — — Net periodic defined benefit costs (credits) $ 83 $ 73 $ 123 $ (116 ) $ (62 ) $ 28 $ 8 $ 12 $ 12 Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: Divestiture (a) $ — $ — $ (353 ) $ — $ — $ — $ — $ — $ (6 ) Settlement (1 ) (3 ) — — — — — — — Net (gain) loss 27 253 63 346 7 508 (28 ) 9 (9 ) Prior service cost (credit) (1 ) 15 18 — — — 8 — — Amortization of: Prior service (cost) credit (10 ) (8 ) (7 ) — — — 1 (1 ) (1 ) Actuarial gain (loss) (69 ) (50 ) (85 ) (144 ) (138 ) (158 ) (1 ) (1 ) — Total recognized in OCI and regulatory assets/liabilities (b) (54 ) 207 (364 ) 202 (131 ) 350 (20 ) 7 (16 ) Total recognized in net periodic defined benefit costs, OCI and regulatory assets/liabilities (b) $ 29 $ 280 $ (241 ) $ 86 $ (193 ) $ 378 $ (12 ) $ 19 $ (4 ) (a) As a result of the spinoff of PPL Energy Supply, amounts in AOCI were allocated to certain former active and inactive employees of PPL Energy Supply and included in the distribution. See Note 8 for additional details. (b) WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. As a result, WPD does not record regulatory assets/liabilities. For PPL's U.S. pension benefits and for other postretirement benefits, the amounts recognized in OCI and regulatory assets/liabilities for the years ended December 31 were as follows: U.S. Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 OCI $ (53 ) $ 236 $ (269 ) $ (25 ) $ 7 $ 12 Regulatory assets/liabilities (1 ) (29 ) (95 ) 5 — (28 ) Total recognized in OCI and regulatory assets/liabilities $ (54 ) $ 207 $ (364 ) $ (20 ) $ 7 $ (16 ) The estimated amounts to be amortized from AOCI and regulatory assets/liabilities into net periodic defined benefit costs in 2018 are as follows: Pension Benefits U.S. U.K. Prior service cost (credit) $ 10 $ — Actuarial (gain) loss 86 152 Total $ 96 $ 152 Amortization from Balance Sheet: AOCI $ 28 $ 152 Regulatory assets/liabilities 68 — Total $ 96 $ 152 (LKE) The following table provides the components of net periodic defined benefit costs for LKE's pension and other postretirement benefit plans for the years ended December 31. Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 Net periodic defined benefit costs (credits): Service cost $ 24 $ 23 $ 26 $ 4 $ 5 $ 5 Interest cost 68 71 68 9 9 9 Expected return on plan assets (92 ) (91 ) (88 ) (7 ) (6 ) (6 ) Amortization of: Prior service cost 8 8 7 1 3 3 Actuarial (gain) loss (a) 31 21 37 — (1 ) — Net periodic defined benefit costs (b) $ 39 $ 32 $ 50 $ 7 $ 10 $ 11 Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: Net (gain) loss $ 30 $ 119 $ 20 $ (14 ) $ 6 $ (15 ) Prior service cost 7 — 19 8 — — Amortization of: Prior service credit (8 ) (8 ) (7 ) (1 ) (3 ) (3 ) Actuarial gain (loss) (32 ) (21 ) (37 ) — 1 — Total recognized in OCI and regulatory assets/liabilities (3 ) 90 (5 ) (7 ) 4 (18 ) Total recognized in net periodic defined benefit costs, OCI and regulatory assets/liabilities $ 36 $ 122 $ 45 $ — $ 14 $ (7 ) (a) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LKE's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $11 million in 2017 , $6 million in 2016 and $9 million in 2015 . (b) Due to the amount of lump sum payment distributions from the LG&E qualified pension plan, a settlement charge of $5 million was incurred. In accordance with existing regulatory accounting treatment, LG&E has maintained the settlement charge in regulatory assets. The amount will be amortized in accordance with existing regulatory practice. For LKE's pension and other postretirement benefits, the amounts recognized in OCI and regulatory assets/liabilities for the years ended December 31 were as follows: Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 OCI $ 33 $ 42 $ 4 $ (2 ) $ 2 $ (2 ) Regulatory assets/liabilities (36 ) 48 (9 ) (5 ) 2 (16 ) Total recognized in OCI and regulatory assets/liabilities $ (3 ) $ 90 $ (5 ) $ (7 ) $ 4 $ (18 ) The estimated amounts to be amortized from AOCI and regulatory assets/liabilities into net periodic defined benefit costs for LKE in 2018 are as follows. Pension Benefits Other Postretirement Benefits Prior service cost $ 9 $ 1 Actuarial Loss 39 — Total $ 48 $ 1 Amortization from Balance Sheet: AOCI $ 11 $ — Regulatory assets/liabilities 37 1 Total $ 48 $ 1 (LG&E) The following table provides the components of net periodic defined benefit costs for LG&E's pension benefit plan for the years ended December 31. Pension Benefits 2017 2016 2015 Net periodic defined benefit costs (credits): Service cost $ 1 $ 1 $ 1 Interest cost 13 15 14 Expected return on plan assets (22 ) (21 ) (20 ) Amortization of: Prior service cost 5 4 3 Actuarial loss (a) 9 7 11 Net periodic defined benefit costs (b) $ 6 $ 6 $ 9 Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets - Gross: Net (gain) loss $ (9 ) $ 22 $ 8 Prior service cost 7 — 10 Amortization of: Prior service credit (5 ) (4 ) (3 ) Actuarial gain (9 ) (7 ) (11 ) Total recognized in regulatory assets/liabilities (16 ) 11 4 Total recognized in net periodic defined benefit costs and regulatory assets $ (10 ) $ 17 $ 13 (a) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LG&E's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $7 million in 2017 , $5 million in 2016 and $3 million in 2015 . (b) Due to the amount of lump sum payment distributions from the LG&E qualified pension plan, a settlement charge of $5 million was incurred. In accordance with existing regulatory accounting treatment, LG&E has maintained the settlement charge in regulatory assets. The amount will be amortized in accordance with existing regulatory practice. The estimated amounts to be amortized from regulatory assets into net periodic defined benefit costs for LG&E in 2018 are as follows. Pension Benefits Prior service cost $ 5 Actuarial loss 9 Total $ 14 (All Registrants) The following net periodic defined benefit costs (credits) were charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 PPL $ 59 $ 53 $ 71 $ (151 ) $ (95 ) $ (21 ) $ 5 $ 7 $ 8 PPL Electric (a) 12 10 15 — 1 — LKE (b) 28 24 37 5 6 8 LG&E (b) 8 8 12 3 3 4 KU (a) (b) 4 5 9 1 2 2 (a) PPL Electric and KU do not directly sponsor any defined benefit plans. PPL Electric and KU were allocated these costs of defined benefit plans sponsored by PPL Services (for PPL Electric) and by LKE (for KU), based on their participation in those plans, which management believes are reasonable. KU is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to KU from LKS. (b) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between net periodic defined benefit costs calculated in accordance with LKE's, LG&E's and KU's pension accounting policy and the net periodic defined benefit costs calculated using a 15 year amortization period for gains and losses is recorded as a regulatory asset. Of the costs charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts, $4 million for LG&E and $2 million for KU were recorded as regulatory assets in 2017 , $3 million for LG&E and $2 million for KU were recorded as regulatory assets in 2016 and $4 million for LG&E and $1 million for KU were recorded as regulatory assets in 2015 . In the table above, LG&E amounts include costs for the specific plans it sponsors and the following allocated costs of defined benefit plans sponsored by LKE. LG&E is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to LG&E from LKS. These allocations are based on LG&E's participation in those plans, which management believes are reasonable: Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 LG&E Non-Union Only $ 5 $ 4 $ 5 $ 3 $ 3 $ 4 (PPL, LKE and LG&E) PPL, LKE and LG&E adopted the new mortality tables issued by the Society of Actuaries in October 2014 (RP-2014 base tables with collar and factor adjustments, where applicable) for all U.S. defined benefit pension and other postretirement benefit plans. In addition, in 2014, PPL, LKE and LG&E updated the basis for estimating projected mortality improvements and selected the IRS BB-2D two-dimensional improvement scale on a generational basis for all U.S. defined benefit pension and other postretirement benefit plans. In 2017, PPL, LKE and LG&E updated to the MP-2017 mortality improvement scale from 2006 on a generational basis. This new mortality assumption reflects the expectation of lower ongoing improvements in life expectancies. The following weighted-average assumptions were used in the valuation of the benefit obligations at December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2017 2016 2017 2016 PPL Discount rate 3.70 % 4.21 % 2.65 % 2.87 % 3.64 % 4.11 % Rate of compensation increase 3.78 % 3.95 % 3.50 % 3.50 % 3.75 % 3.92 % LKE Discount rate 3.69 % 4.19 % 3.65 % 4.12 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % LG&E Discount rate 3.65 % 4.13 % The following weighted-average assumptions were used to determine the net periodic defined benefit costs for the years ended December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 PPL Discount rate service cost (b) 4.21 % 4.59 % 4.25 % 2.99 % 3.90 % 3.85 % 4.11 % 4.48 % 4.09 % Discount rate interest cost (b) 4.21 % 4.59 % 4.25 % 2.41 % 3.14 % 3.85 % 4.11 % 4.48 % 4.09 % Rate of compensation increase 3.95 % 3.93 % 3.91 % 3.50 % 4.00 % 4.00 % 3.92 % 3.91 % 3.86 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 7.22 % 7.20 % 7.19 % 6.21 % 6.11 % 6.06 % LKE Discount rate 4.19 % 4.56 % 4.25 % 4.12 % 4.49 % 4.06 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 6.82 % 6.82 % 6.82 % Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 LG&E Discount rate 4.13 % 4.49 % 4.20 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % (a) The expected long-term rates of return for pension and other postretirement benefits are based on management's projections using a best-estimate of expected returns, volatilities and correlations for each asset class. Each plan's specific current and expected asset allocations are also considered in developing a reasonable return assumption. (b) As of January 1, 2016, WPD began using individual spot rates from the yield curve used to discount the benefit obligation to measure service cost and interest cost. PPL's U.S. plans use a single discount rate derived from an individual bond matching model to measure the benefit obligation, service cost and interest cost. See Note 1 for additional details. (PPL and LKE) The following table provides the assumed health care cost trend rates for the years ended December 31: 2017 2016 2015 PPL and LKE Health care cost trend rate assumed for next year – obligations 6.6 % 7.0 % 6.8 % – cost 7.0 % 6.8 % 7.2 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) – obligations 5.0 % 5.0 % 5.0 % – cost 5.0 % 5.0 % 5.0 % Year that the rate reaches the ultimate trend rate – obligations 2022 2022 2020 – cost 2022 2020 2020 A one percentage point change in the assumed health care costs trend rate assumption would have had the following effects on the other postretirement benefit plans in 2017 : One Percentage Point Increase Decrease Effect on accumulated postretirement benefit obligation PPL $ 4 $ (4 ) LKE 3 (3 ) (PPL) The funded status of PPL's plans at December 31 was as follows: Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2017 2016 2017 2016 Change in Benefit Obligation Benefit Obligation, beginning of period $ 4,079 $ 3,863 $ 7,383 $ 8,404 $ 591 $ 596 Service cost 65 66 76 69 7 7 Interest cost 168 174 178 235 23 26 Participant contributions — — 13 14 14 14 Plan amendments (1 ) 14 — — 8 — Actuarial (gain) loss 233 214 293 484 4 11 Settlements (6 ) (9 ) (1 ) — — — Termination benefits 1 — — — — — Gross benefits paid (251 ) (243 ) (345 ) (357 ) (59 ) (64 ) Federal subsidy — — — — 1 1 Currency conversion — — 622 (1,466 ) — — Benefit Obligation, end of period 4,288 4,079 8,219 7,383 589 591 Change in Plan Assets Plan assets at fair value, beginning of period 3,243 3,227 7,211 7,625 378 379 Actual return on plan assets 437 189 480 979 54 25 Employer contributions 65 79 486 330 15 19 Participant contributions — — 13 14 13 14 Settlements (6 ) (9 ) (1 ) — — — Gross benefits paid (251 ) (243 ) (345 ) (357 ) (55 ) (59 ) Currency conversion — — 646 (1,380 ) — — Plan assets at fair value, end of period 3,488 3,243 8,490 7,211 405 378 Funded Status, end of period $ (800 ) $ (836 ) $ 271 $ (172 ) $ (184 ) $ (213 ) Amounts recognized in the Balance Sheets consist of: Noncurrent asset $ — $ — $ 284 $ 10 $ 2 $ 2 Current liability (13 ) (17 ) — — (3 ) (3 ) Noncurrent liability (787 ) (819 ) (13 ) (182 ) (183 ) (212 ) Net amount recognized, end of period $ (800 ) $ (836 ) $ 271 $ (172 ) $ (184 ) $ (213 ) Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax) consist of: Prior service cost (credit) $ 49 $ 59 $ — $ — $ 9 $ — Net actuarial (gain) loss 1,134 1,178 2,755 2,553 16 45 Total (a) $ 1,183 $ 1,237 $ 2,755 $ 2,553 $ 25 $ 45 Total accumulated benefit obligation for defined benefit pension plans $ 4,000 $ 3,807 $ 7,542 $ 6,780 (a) WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP and as a result, does not record regulatory assets/liabilities. For PPL's U.S. pension and other postretirement benefit plans, the amounts recognized in AOCI and regulatory assets/liabilities at December 31 were as follows: U.S. Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 AOCI $ 374 $ 357 $ 15 $ 20 Regulatory assets/liabilities 809 880 10 25 Total $ 1,183 $ 1,237 $ 25 $ 45 The following tables provide information on pension plans where the projected benefit obligation (PBO) or accumulated benefit obligation (ABO) exceed the fair value of plan assets: U.S. U.K. PBO in excess of plan assets PBO in excess of plan assets 2017 2016 2017 2016 Projected benefit obligation $ 4,288 $ 4,079 $ 3,083 $ 3,403 Fair value of plan assets 3,488 3,243 3,070 3,221 U.S. U.K. ABO in excess of plan assets ABO in excess of plan assets 2017 2016 2017 2016 Accumulated benefit obligation $ 4,000 $ 3,807 $ 10 $ 657 Fair value of plan assets 3,488 3,243 — 643 (LKE) The funded status of LKE's plans at December 31 was as follows: Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 Change in Benefit Obligation Benefit Obligation, beginning of period $ 1,669 $ 1,588 $ 220 $ 216 Service cost 24 23 4 5 Interest cost 68 71 9 9 Participant contributions — — 8 7 Plan amendments (a) 6 — 8 — Actuarial (gain) loss 113 96 (7 ) 4 Gross benefits paid (a) (109 ) (109 ) (19 ) (21 ) Benefit Obligation, end of period 1,771 1,669 223 220 Change in Plan Assets Plan assets at fair value, beginning of period 1,315 1,289 98 88 Actual return on plan assets 175 69 14 4 Employer contributions 21 66 15 20 Participant contributions — — 8 7 Gross benefits paid (109 ) (109 ) (19 ) (21 ) Plan assets at fair value, end of period 1,402 1,315 116 98 Funded Status, end of period $ (369 ) $ (354 ) $ (107 ) $ (122 ) Amounts recognized in the Balance Sheets consist of: Noncurrent asset $ — $ — $ 2 $ 2 Current liability (4 ) (4 ) (3 ) (3 ) Noncurrent liability (365 ) (350 ) (106 ) (121 ) Net amount recognized, end of period $ (369 ) $ (354 ) $ (107 ) $ (122 ) Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax) consist of: Prior service cost $ 44 $ 45 $ 13 $ 6 Net actuarial (gain) loss 434 436 (26 ) (13 ) Total $ 478 $ 481 $ (13 ) $ (7 ) Total accumulated benefit obligation for defined benefit pension plans $ 1,616 $ 1,531 (a) The pension plans were amended in December 2015 to allow active participants and terminated vested participants who had not previously elected a form of payment of their benefit to elect to receive their accrued pension benefit as a one-time lump-sum payment effective January 1, 2016. The projected benefit obligation at December 31, 2016 increased by $19 million as a result of the amendment. Gross benefits paid by the plans include lump-sum cash payments made to participants during 2017 and 2016 of $50 million and $53 million in connection with these offerings. The amounts recognized in AOCI and regulatory assets/liabilities at December 31 were as follows: Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 AOCI $ 144 $ 111 $ 6 $ 8 Regulatory assets/liabilities 334 370 (19 ) (15 ) Total $ 478 $ 481 $ (13 ) $ (7 ) The following tables provide information on pension plans where the projected benefit obligation (PBO) or accumulated benefit obligations (ABO) exceed the fair value of plan assets: PBO in excess of plan assets 2017 2016 Projected benefit obligation $ 1,771 $ 1,669 Fair value of plan assets 1,402 1,315 ABO in excess of plan assets 2017 2016 Accumulated benefit obligation $ 1,616 $ 1,531 Fair value of plan assets 1,402 1,315 (LG&E) The funded status of LG&E's plan at December 31, was as follows: Pension Benefits 2017 2016 Change in Benefit Obligation Benefit Obligation, beginning of period $ 329 $ 326 Service cost 1 1 Interest cost 13 15 Plan amendments (a) 6 — Actuarial (gain) loss 11 15 Gross benefits paid (a) (34 ) (28 ) Benefit Obligation, end of period 326 329 Change in Plan Assets Plan assets at fair value, beginning of period 318 297 Actual return on plan assets 41 14 Employer contributions — 35 Gross benefits paid (34 ) (28 ) Plan assets at fair value, end of period 325 318 Funded Status, end of period $ (1 ) $ (11 ) Amounts recognized in the Balance Sheets consist of: Noncurrent liability $ (1 ) $ (11 ) Net amount recognized, end of period $ (1 ) $ (11 ) Amounts recognized in regulatory assets (pre-tax) consist of: Prior service cost $ 27 $ 25 Net actuarial loss 92 110 Total $ 119 $ 135 Total accumulated benefit obligation for defined benefit pension plan $ 326 $ 329 (a) The pension plan was amended in December 2015 to allow active participants and terminated vested participants who had not previously elected a form of payment of their benefit to elect to receive their accrued pension benefit as a one-time lump-sum payment effective January 1, 2016. The projected benefit obligation at December 31, 2015 increased by $10 million as a result of the amendment. Gross benefits paid by the plan include lump-sum cash payments made to participants during 2017 and 2016 of $19 million and $14 million in connection with this offering. LG&E's pension plan had projected and accumulated benefit obligations in excess of plan assets at December 31, 2017 and 2016 . In addition to the plan it sponsors, LG&E is allocated a portion of the funded status and costs of certain defined benefit plans sponsored by LKE. LG&E is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to LG&E from LKS. These allocations are based on LG&E's participation in those plans, which management believes are reasonable. The actuarially determined obligations of current active employees and retired employees are used as a basis to allocate total plan activity, including active and retiree costs and obligations. Allocations to LG&E resulted in liabilities at December 31 as follows: 2017 2016 Pension $ 44 $ 42 Other postretirement benefits 74 76 (PPL Electric) Although PPL Electric does not directly sponsor any defined benefit plans, it is allocated a portion of the funded status and costs of plans sponsored by PPL Services based on its participation in those plans, which management believes are reasonable. As a result of the spinoff of PPL Energy Supply in 2015, pension and other postretirement plans were remeasured resulting in adjustments to PPL Electric's allocated balances of $56 million , reflected as a non-cash contribution on the Statement of Equity. The actuarially determined obligations of current active employees and retirees are used as a basis to allocate total plan activity, including active and retiree costs and obligations. Allocations to PPL Electric resulted in liabilities at December 31 as follows: 2017 2016 Pension $ 246 $ 281 Other postretirement benefits 62 72 (KU) Although KU does not directly sponsor any defined benefit plans, it is allocated a portion of the funded status and costs of plans sponsored by LKE. KU is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to KU from LKS. These allocations are based on KU's participation in those plans, which management believes are reasonable. The actuarially determined obligations of current active employees and retired employees of KU are used as a basis to allocate total plan activity, including active and retiree costs and obligations. Allocations to KU resulted in liabilities at December 31 as follows. 2017 2016 Pension $ 36 $ 62 Other postretirement benefits 32 40 Plan Assets - U.S. Pension Plans (PPL, LKE and LG&E) PPL's primary legacy pension plan and the pension plans sponsored by LKE are invested in the PPL Services Corporation Master Trust (the Master Trust) that also includes 401(h) accounts that are restricted for certain other postretirement benefit obligations of PPL and LKE. The investment strategy for the Master Trust is to achieve a risk-adjusted return on a mix of assets that, in combination with PPL's funding policy, will ensure that sufficient assets are available to provide long-term growth and liquidity for benefit payments, while also managing the duration of the assets to complement the duration of the liabilities. The Master Trust benefits from a wide diversification of asset types, investment fund strategies and external investment fund managers, and therefore has no significant concentration of risk. The investment policy of the Master Trust outlines investment objectives and defines the responsibilities of the EBPB, external investment managers, investment advisor and trustee and custodian. The investment policy is reviewed annually by PPL's Board of Directors. The EBPB created a risk management framework around the trust assets and pension liabilities. This framework considers the trust assets as being composed of three sub-portfolios: growth, immunizing and liquidity portfolios. The growth portfolio is comprised of investments that generate a return at a reasonable risk, including equity securities, certain debt securities and alternative investments. The immunizing portfolio consists of debt securities, generally with long durations, and derivative positions. The immunizing portfolio is designed to offset a portion of the change in the pension liabilities due to changes in interest rates. The liquidity portfolio consists primarily of cash and cash equivalents. Target allocation ranges have been developed for each portfolio based on input from external consultants with a goal of limiting funded status volatility. The EBPB monitors the investments in each portfolio, and seeks to obtain a target portfolio that emphasizes reduction of risk of loss from market volatility. In pursuing that goal, the EBPB establishes revised guidelines from time to time. EBPB investment guidelines as of the end of 2017 are presented below. The asset allocation for the trust and the target allocation by portfolio at December 31 are as follows: Percentage of trust assets 2017 2017 (a) 2016 Target Asset Allocation (a) Growth Portfolio 56 % 52 % 55 % Equity securities 32 % 30 % Debt securities (b) 14 % 12 % Alternative investments 10 % 10 % Immunizing Portfolio 43 % 46 % 43 % Debt securities (b) 39 % 43 % Derivatives 4 % 3 % Liquidity Portfolio 1 % 2 % 2 % Total 100 % 100 % 100 % (a) Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan. (b) Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes. (LKE) LKE has pension plans, including LG&E's plan, whose assets are invested solely in the Master Trust, which is fully disclosed below. The fair value of these plans' assets of $1.4 billion and $1.3 billion at December 31, 2017 and 2016 represents an interest of approximately 40% and 41% in the Master Trust. (LG&E) LG&E has a pension plan whose assets are invested solely in the Master Trust, which is fully disclosed below. The fair value of this plan's assets of $325 million and $318 million at December 31, 2017 and 2016 represents an interest of approximately 9% and 10% in the Master Trust. (PPL, LKE and LG&E) The fair value of net assets in the Master Trust by asset class and level within the fair value hierarchy was: December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 PPL Services Corporation Master Trust Cash and cash equivalents $ 301 $ 301 $ — $ — $ 181 $ 181 $ — $ — Equity securities: U.S. Equity 229 229 — — 152 152 — — U.S. Equity fund measured at NAV (a) 364 — — — 272 — — — International equity fund at NAV (a) 538 — — — 551 — — — Commingled debt measured at NAV (a) 611 — — — 546 — — — December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Debt securities: U.S. Treasury and U.S. government sponsored agency 186 186 — — 381 381 — — Corporate 883 — 870 13 850 — 837 13 Other 10 — 10 — 8 — 8 — Alternative investments: Real estate measured at NAV (a) 109 — — — 102 — — — Private equity measured at NAV (a) 80 — — — 80 — — — Hedge funds measured at NAV (a) 175 — — — 167 — — — Derivatives: Interest rate swaps and swaptions 50 — 50 — 61 — 61 — Other 1 — 1 — 3 — 3 — Insurance contracts 24 — — 24 27 — — 27 PPL Services Corporation Master Trust assets, at fair value 3,561 $ 716 $ 931 $ 37 3,381 $ 714 $ 909 $ 40 Receivables and payables, net (b) 72 (15 ) 401(h) accounts restricted for other postretirement benefit obligations (145 ) (123 ) Total PPL Services Corporation Master Trust pension assets $ 3,488 $ 3,243 (a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. (b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received. A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2017 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 13 $ 27 $ 40 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements — (4 ) (4 ) Balance at end of period $ 13 $ 24 $ 37 A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2016 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 10 $ 32 $ 42 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements 3 (6 ) (3 ) Balance at end of period $ 13 $ 27 $ 40 The fair value measurements of cash and cash equivalents are based on the amounts on deposit. The market approach is used to measure fair value of equity securities. The fair value measurements of equity securities (excluding commingled funds), which are generally classified as Level 1, are based on quoted prices in active markets. These securities represent actively and passively managed investments that are managed against various equity indices. Investments in commingled equity and debt funds are categorized as equity securities. Investments in commingled equity funds include funds that invest in U.S. and international equity securities. Investments in commingled debt funds include funds that invest in a diversified portfolio of emerging market debt obligations, as

Jointly Owned Facilities

Jointly Owned Facilities	12 Months Ended
	Dec. 31, 2017
Jointly Owned Facilities [Line Items]
Jointly Owned Facilities	12. Jointly Owned Facilities (PPL, LKE, LG&E and KU) At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — — Each subsidiary owning these interests provides its own funding for its share of the facility. Each receives a portion of the total output of the generating plants equal to its percentage ownership. The share of fuel and other operating costs associated with the plants is included in the corresponding operating expenses on the Statements of Income.
LG And E And KU Energy LLC [Member]
Jointly Owned Facilities [Line Items]
Jointly Owned Facilities	12. Jointly Owned Facilities (PPL, LKE, LG&E and KU) At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — — Each subsidiary owning these interests provides its own funding for its share of the facility. Each receives a portion of the total output of the generating plants equal to its percentage ownership. The share of fuel and other operating costs associated with the plants is included in the corresponding operating expenses on the Statements of Income.
Louisville Gas And Electric Co [Member]
Jointly Owned Facilities [Line Items]
Jointly Owned Facilities	12. Jointly Owned Facilities (PPL, LKE, LG&E and KU) At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — — Each subsidiary owning these interests provides its own funding for its share of the facility. Each receives a portion of the total output of the generating plants equal to its percentage ownership. The share of fuel and other operating costs associated with the plants is included in the corresponding operating expenses on the Statements of Income.
Kentucky Utilities Co [Member]
Jointly Owned Facilities [Line Items]
Jointly Owned Facilities	12. Jointly Owned Facilities (PPL, LKE, LG&E and KU) At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — — Each subsidiary owning these interests provides its own funding for its share of the facility. Each receives a portion of the total output of the generating plants equal to its percentage ownership. The share of fuel and other operating costs associated with the plants is included in the corresponding operating expenses on the Statements of Income.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. Commitments and Contingencies (PPL) All commitments, contingencies and guarantees associated with PPL Energy Supply and its subsidiaries were retained by Talen Energy and its subsidiaries at the spinoff date without recourse to PPL. Energy Purchase Commitments (PPL, LKE, LG&E and KU) LG&E and KU enter into purchase contracts to supply the coal and natural gas requirements for generation facilities and LG&E's retail natural gas supply operations. These contracts include the following commitments: Contract Type Maximum Maturity Date Natural Gas Fuel 2019 Natural Gas Retail Supply 2019 Coal 2023 Coal Transportation and Fleeting Services 2024 Natural Gas Transportation 2026 LG&E and KU have a power purchase agreement with OVEC expiring in June 2040 . See footnote (f) to the table in "Guarantees and Other Assurances" below for information on the OVEC power purchase contract, including recent developments in credit or debt conditions relating to OVEC. Future obligations for power purchases from OVEC are unconditional demand payments, comprised of debt-service payments and contractually-required reimbursements of plant operating, maintenance and other expenses, and are projected as follows: LG&E KU Total 2018 $ 20 $ 9 $ 29 2019 19 8 27 2020 18 8 26 2021 19 8 27 2022 19 8 27 Thereafter 316 141 457 Total $ 411 $ 182 $ 593 LG&E and KU had total energy purchases under the OVEC power purchase agreement for the years ended December 31 as follows: 2017 2016 2015 LG&E $ 14 $ 16 $ 15 KU 6 7 7 Total $ 20 $ 23 $ 22 Legal Matters (All Registrants) PPL and its subsidiaries are involved in legal proceedings, claims and litigation in the ordinary course of business. PPL and its subsidiaries cannot predict the outcome of such matters, or whether such matters may result in material liabilities, unless otherwise noted. WKE Indemnification (PPL and LKE) See footnote (e) to the table in "Guarantees and Other Assurances" below for information on an LKE indemnity relating to its former WKE lease, including related legal proceedings. (PPL, LKE and LG&E) Cane Run Environmental Claims In December 2013, six residents, on behalf of themselves and others similarly situated, filed a class action complaint against LG&E and PPL in the U.S. District Court for the Western District of Kentucky alleging violations of the Clean Air Act, RCRA, and common law claims of nuisance, trespass and negligence. These plaintiffs seek injunctive relief and civil penalties, plus costs and attorney fees, for the alleged statutory violations. Under the common law claims, these plaintiffs seek monetary compensation and punitive damages for property damage and diminished property values for a class consisting of residents within four miles of the Cane Run plant. In their individual capacities, these plaintiffs sought compensation for alleged adverse health effects. In July 2014, the court dismissed the RCRA claims and all but one Clean Air Act claim, but declined to dismiss the common law tort claims. In November 2016, the plaintiffs filed an amended complaint removing the personal injury claims and removing certain previously named plaintiffs. In February 2017, the District Court issued an order dismissing PPL as a defendant and dismissing the final federal claim against LG&E. On April 13, 2017, the federal District Court issued an order declining to exercise supplemental jurisdiction on the state law claims and dismissed the case in its entirety. On June 16, 2017, the plaintiffs filed a class action complaint in Jefferson Circuit Court, Kentucky, against LG&E alleging state law nuisance, negligence and trespass tort claims. The plaintiffs seek compensatory and punitive damages for alleged property damage due to purported plant emissions on behalf of a class of residents within one to three miles of the plant. Proceedings are currently underway regarding potential class certification, for which a decision may occur in late 2018 or in 2019. PPL, LKE and LG&E cannot predict the outcome of this matter. LG&E retired one coal-fired unit at the Cane Run plant in March 2015 and the remaining two coal-fired units at the plant in June 2015. (PPL, LKE and KU) E.W. Brown Environmental Claims On July 12, 2017, the Kentucky Waterways Alliance and the Sierra Club filed a citizen suit complaint against KU in the U.S. District Court for the Eastern District of Kentucky alleging discharges at the E.W. Brown plant in violation of the Clean Water Act and the plant's water discharge permit and alleging contamination that may present an imminent and substantial endangerment in violation of the RCRA. The plaintiffs' suit relates to prior notices of intent to file a citizen suit submitted in October and November 2015 and October 2016. These plaintiffs sought injunctive relief ordering KU to take all actions necessary to comply with the Clean Water Act and RCRA, including ceasing the discharges in question, abating effects associated with prior discharges and eliminating the alleged imminent and substantial endangerment. These plaintiffs also sought assessment of civil penalties and an award of litigation costs and attorney fees. On December 28, 2017 the U.S. District Court for the Eastern District of Kentucky issued an order dismissing the Clean Water Act and RCRA complaints against KU in their entirety. On January 26, 2018, the plaintiffs appealed the dismissal order to the U.S. Court of Appeals for the Sixth Circuit. KU is undertaking extensive remedial measures at the Brown plant including closure of the former ash pond, implementation of a groundwater remedial action plan, and performance of a corrective action plan including aquatic study of adjacent surface waters and risk assessment. PPL, LKE and KU cannot predict the outcome of these matters. (PPL, LKE, LG&E and KU) Trimble County Water Discharge Permit In May 2010, the Kentucky Waterways Alliance and other environmental groups filed a petition with the Kentucky Energy and Environment Cabinet (KEEC) challenging the Kentucky Pollutant Discharge Elimination System permit issued in April 2010, which covers water discharges from the Trimble County plant. In November 2010, the KEEC issued a final order upholding the permit, which was subsequently appealed by the environmental groups. In September 2013, the Franklin Circuit Court reversed the KEEC order and remanded the permit to the agency for further proceedings. LG&E and the KEEC appealed the order to the Kentucky Court of Appeals. In July 2015, the Court of Appeals upheld the lower court ruling. LG&E and the KEEC moved for discretionary review by the Kentucky Supreme Court. In February 2016, the Kentucky Supreme Court issued an order granting discretionary review and oral arguments were held in September 2016. On April 27, 2017, the Kentucky Supreme Court issued an order reversing the decision of the appellate court and upholding the permit issued to LG&E by the KEEC. Trimble County Landfill Various state and federal permits and regulatory approvals are required in order to construct a landfill at the Trimble County plant to be used for disposal of CCRs. In October 2016, the Kentucky Division of Water issued a water quality certification and in February 2017, the Kentucky Division of Waste Management issued a "special waste" landfill permit. In March 2017, the Sierra Club and a resident adjacent to the plant filed administrative challenges to the landfill permit which were subsequently dismissed by agreed order entered in August 2017. In June 2017, the U.S. Army Corps of Engineers issued a dredge and fill permit, the final approval required for construction of the landfill. PPL, LKE, LG&E and KU believe that all permits and regulatory approvals issued for the project comply with applicable state and federal laws. (All Registrants) Regulatory Issues See Note 6 for information on regulatory matters related to utility rate regulation. Electricity - Reliability Standards The NERC is responsible for establishing and enforcing mandatory reliability standards (Reliability Standards) regarding the bulk electric system in North America. The FERC oversees this process and independently enforces the Reliability Standards. The Reliability Standards have the force and effect of law and apply to certain users of the bulk electric system, including electric utility companies, generators and marketers. Under the Federal Power Act, the FERC may assess civil penalties for certain violations. PPL Electric, LG&E and KU monitor their compliance with the Reliability Standards and self-report or self-log potential violations of applicable reliability requirements whenever identified, and submit accompanying mitigation plans, as required. The resolution of a small number of potential violations is pending. Penalties incurred to date have not been significant. Any Regional Reliability Entity (including RFC or SERC) determination concerning the resolution of violations of the Reliability Standards remains subject to the approval of the NERC and the FERC. In the course of implementing their programs to ensure compliance with the Reliability Standards by those PPL affiliates subject to the standards, certain other instances of potential non-compliance may be identified from time to time. The Registrants cannot predict the outcome of these matters, and cannot estimate a range of reasonably possible losses, if any. Environmental Matters (All Registrants) Due to the environmental issues discussed below or other environmental matters, it may be necessary for the Registrants to modify, curtail, replace or cease operation of certain facilities or performance of certain operations to comply with statutes, regulations and other requirements of regulatory bodies or courts. In addition, legal challenges to new environmental permits or rules add to the uncertainty of estimating the future cost of these permits and rules. Finally, the regulatory reviews specified in the President's March 2017 Executive Order (the March 2017 Executive Order) promoting energy independence and economic growth could result in future regulatory changes and additional uncertainty. WPD's distribution businesses are subject to certain statutory and regulatory environmental requirements. It may be necessary for WPD to incur significant compliance costs, which costs may be recoverable through rates subject to the approval of Ofgem. PPL believes that WPD has taken and continues to take measures to comply with all applicable environmental laws and regulations. LG&E and KU are entitled to recover, through the ECR mechanism, certain costs of complying with the Clean Air Act, as amended, and those federal, state or local environmental requirements applicable to coal combustion wastes and by-products from facilities that generate electricity from coal in accordance with approved compliance plans. Costs not covered by the ECR mechanism for LG&E and KU and all such costs for PPL Electric are subject to rate recovery before the companies' respective state regulatory authorities, or the FERC, if applicable. Because neither WPD nor PPL Electric owns any generating plants, their exposure to related environmental compliance costs is reduced. PPL, PPL Electric, LKE, LG&E and KU can provide no assurances as to the ultimate outcome of future environmental or rate proceedings before regulatory authorities. Air (PPL, LKE, LG&E and KU) NAAQS The Clean Air Act, which regulates air pollutants from mobile and stationary sources in the United States, has a significant impact on the operation of fossil fuel generation plants. Among other things, the Clean Air Act requires the EPA periodically to review and establish concentration levels in the ambient air for six pollutants to protect public health and welfare. The six pollutants are carbon monoxide, lead, nitrogen dioxide, ozone (contributed to by nitrogen oxide emissions), particulate matter and sulfur dioxide. The established concentration levels for these six pollutants are known as NAAQS. Under the Clean Air Act, the EPA is required to reassess the NAAQS on a five-year schedule. Federal environmental regulations of these six pollutants require states to adopt implementation plans, known as state implementation plans, which detail how the state will attain the standards that are mandated by the relevant law or regulation. Each state identifies the areas within its boundaries that meet the NAAQS (attainment areas) and those that do not (non-attainment areas), and must develop a state implementation plan both to bring non-attainment areas into compliance with the NAAQS and to maintain good air quality in attainment areas. In addition, for attainment of ozone and fine particulates standards, states in the eastern portion of the country, including Kentucky, are subject to a regional program developed by the EPA known as the Cross-State Air Pollution Rule. The NAAQS, future revisions to the NAAQS and state implementation plans, or future revisions to regional programs, may require installation of additional pollution controls, the costs of which PPL, LKE, LG&E and KU believe are subject to cost recovery. Although PPL, LKE, LG&E and KU do not anticipate significant costs to comply with these programs, changes in market or operating conditions could result in different costs than anticipated. Ozone The EPA issued the current ozone standard in October 2015. The states and the EPA are required to determine (based on ambient air monitoring data) those areas that meet the standard and those that are in non-attainment. The EPA was scheduled to designate areas as being in attainment or nonattainment of the current ozone standard by no later than October 2017 which was to be followed by further regulatory proceedings identifying compliance measures and deadlines. However, the current implementation and compliance schedule is uncertain because the EPA failed to make nonattainment demonstrations by the applicable deadline. In addition, some industry groups have requested the EPA to defer implementation of the 2015 ozone standard, but the EPA has not yet acted on this request. While implementation of the 2015 ozone standard could potentially require the addition of SCRs at some LG&E and KU generating units, PPL, LKE, LG&E and KU are currently unable to determine what the compliance measures and deadlines may ultimately be with respect to the new standard. States are also obligated to address interstate transport issues associated with ozone standards through the establishment of "good neighbor" state implementation plans for those states that are found to contribute significantly to another state's non-attainment. As a result of a partial consent decree addressing claims regarding federal implementation, the EPA and several states, including Kentucky, are evaluating the need for further nitrogen oxide reductions from fossil-fueled plants to address interstate impacts. While PPL, LKE, LG&E, and KU are unable to predict the outcome of ongoing and future evaluations by the EPA and the states, such evaluations could potentially result in requirements for nitrogen oxide reductions beyond those currently required under the Cross State Air Pollution Rule. Sulfur Dioxide In 2010, the EPA issued the current NAAQS for sulfur dioxide and required states to identify areas that meet those standards and areas that are in "non-attainment". In July 2013, the EPA finalized non-attainment designations for parts of the country, including part of Jefferson County in Kentucky. Attainment must be achieved by 2018 . As a result of scrubber replacements completed by LG&E at the Mill Creek plant in 2016, all Jefferson County monitors now indicate compliance with the sulfur dioxide standards. Additionally, LG&E accepted a new sulfur dioxide emission limit to ensure continuing compliance with the NAAQS. PPL, LKE, LG&E and KU do not anticipate any further measures to achieve compliance with the new sulfur dioxide standards. Climate Change There is continuing world-wide attention focused on issues related to climate change. In June 2016, President Obama announced that the United States, Canada and Mexico established the North American Climate, Clean Energy, and Environment Partnership Plan, which specifies actions to promote clean energy, address climate change and protect the environment. The plan includes a goal to provide 50% of the energy used in North America from clean energy sources by 2025. The plan does not impose any nation-specific requirements. In December 2015, 195 nations, including the U.S., signed the Paris Agreement on Climate, which establishes a comprehensive framework for the reduction of GHG emissions from both developed and developing nations. Although the agreement does not establish binding reduction requirements, it requires each nation to prepare, communicate, and maintain GHG reduction commitments. Reductions can be achieved in a variety of ways, including energy conservation, power plant efficiency improvements, reduced utilization of coal-fired generation or replacing coal-fired generation with natural gas or renewable generation. Based on the EPA's rules issued in 2015 imposing GHG emission standards for both new and existing power plants, the U.S. committed to an initial reduction target of 26% to 28% below 2005 levels by 2025. However, on June 1, 2017, President Trump announced a plan to withdraw from the Paris Agreement and undertake negotiations to reenter the current agreement or enter a new agreement on terms more favorable to the U.S. Under the terms of the Paris Agreement, any U.S. withdrawal would not be complete until November 2020. Additionally, the March 2017 Executive Order directed the EPA to review its 2015 greenhouse gas rules for consistency with certain policy directives and suspend, revise, or rescind those rules as appropriate. The March 2017 Executive Order also directs rescission of specified guidance, directives, and prior Presidential actions regarding climate change. PPL, LKE, LG&E, and KU cannot predict the outcome of such regulatory actions or the impact, if any, on plant operations, rate treatment or future capital or operating needs. The U.K. has enacted binding carbon reduction requirements that are applicable to WPD. Under the U.K. law, WPD must purchase carbon allowances to offset emissions associated with WPD's operations. The cost of these allowances is not significant and is included in WPD's current operating expenses. The EPA's Rules under Section 111 of the Clean Air Act There continues to be uncertainty around the EPA's regulation of existing coal-fired power plants. In 2015 the EPA had finalized rules imposing GHG emission standards for both new and existing power plants and had proposed a federal implementation plan that would apply to any states that failed to submit an acceptable state implementation plan to reduce GHG emissions on a state-by-state basis (the 2015 EPA Rules). Following legal challenges to the 2015 EPA Rules, a stay of those rules by the U.S. Supreme Court, and the President's March 2017 Executive Order (requiring the EPA to review the 2015 EPA Rules), however, in October 2017, the EPA proposed to rescind the 2015 EPA Rules and in December 2017, released an advanced notice of proposed rulemaking for a replacement rule (Replacement Rules) which contemplates GHG reductions based on "inside the fence" measures implemented at individual plants. The contemplated approach in the Replacement Rules is a more limited approach than that taken in the 2015 EPA Rules which had included assumed increased levels of fuel switching and renewable energy in determining the level of emission reduction required by each state. At present, the 2015 EPA Rules remain stayed and the Replacement Rules have not yet been published. In April 2014, the Kentucky General Assembly passed legislation limiting the measures that the Kentucky Energy and Environment Cabinet may consider in setting performance standards to comply with the 2015 EPA Rules, if enacted. The legislation provides that such state GHG performance standards will be based on emission reductions, efficiency measures and other improvements available at each power plant, rather than renewable energy, end-use energy efficiency, fuel switching and re-dispatch. These statutory restrictions are consistent with the EPA's notice of proposed rulemaking on the Replacement Rules. LG&E and KU are monitoring developments at the state and federal level. Until there is more clarity about the potential requirements that may be imposed under the Replacement Rules and Kentucky's implementation plan, PPL, LKE, LG&E and KU cannot predict the potential impact, if any, on plant operations, future capital or operating costs. PPL, LKE, LG&E and KU believe that the costs, which could be significant, would be subject to rate recovery. Sulfuric Acid Mist Emissions (PPL, LKE and LG&E) In June 2016, the EPA issued a notice of violation under the Clean Air Act alleging that LG&E violated applicable rules relating to sulfuric acid mist emissions at its Mill Creek plant. The notice alleges failure to install proper controls, failure to operate the facility consistent with good air pollution control practice, and causing emissions exceeding applicable requirements or constituting a nuisance or endangerment. LG&E believes it has complied with applicable regulations during the relevant time period. Discussions between the EPA and LG&E are ongoing. The parties have entered into a tolling agreement with respect to this matter through December 2018. PPL, LKE and LG&E are unable to predict the outcome of this matter or the potential impact on operations of the Mill Creek plant, including increased capital or operating costs, and potential civil penalties or remedial measures, if any. Water/Waste (PPL, LKE, LG&E and KU) CCRs In April 2015, the EPA published its final rule regulating CCRs. CCRs include fly ash, bottom ash and sulfur dioxide scrubber wastes. The rule became effective in October 2015. It imposes extensive new requirements, including location restrictions, design and operating standards, groundwater monitoring and corrective action requirements, and closure and post-closure care requirements on CCR impoundments and landfills that are located on active power plants in the United States and not closed. Under the rule, CCRs are regulated as non-hazardous under Subtitle D of RCRA and beneficial use of CCRs is allowed, with some restrictions. The rule's requirements for covered CCR impoundments and landfills include implementation of groundwater monitoring and commencement or completion of closure activities generally between three and ten years from certain triggering events. The rule requires posting of compliance documentation on a publicly accessible website. Industry groups, environmental groups, individual companies and others have filed legal challenges to the final rule, which are pending before the D.C. Circuit Court of Appeals. The EPA has advised the court that it expects to reconsider certain aspects of the CCR Rule in the near future. In January 2017, Kentucky issued a new state rule relating to CCR matters, effective May 2017, aimed at reflecting the requirements of the federal CCR Rule. In May 2017, a resident adjacent to LG&E's and KU's Trimble County plant filed a lawsuit in Franklin County, Kentucky Circuit Court against the Kentucky Energy and Environmental Cabinet and LG&E seeking to invalidate the new rule. On January 31, 2018, the state court issued an opinion invalidating certain elements of the new rule. PPL, LKE, LG&E and KU cannot predict the ultimate outcome of the litigation. LG&E and KU presently operate their Trimble County facilities under continuing permits authorized via the former program and do not currently anticipate material impacts as a result of the challenge to the new rule. Separately, in December 2016, federal legislation was enacted that authorized the EPA to approve equally protective state programs that would operate in lieu of the CCR Rule. The Kentucky Energy and Environmental Cabinet indicated it may propose rules under such authority in the future. LG&E and KU received KPSC approval for a compliance plan providing for construction of additional landfill capacity at the E.W. Brown station, closure of impoundments at the Mill Creek, Trimble County, E.W. Brown, and Ghent stations, and construction of process water management facilities at those plants. In addition to the foregoing measures required for compliance with federal CCR rule requirements, KU also received KPSC approval for its plans to close impoundments at the retired Green River, Pineville and Tyrone plants to comply with applicable state law requirements. See Note 6 for additional information. In connection with the final CCR rule, LG&E and KU recorded adjustments to existing AROs during 2015, 2016 and 2017. See Note 19 for additional information. Further changes to AROs, current capital plans or operating costs may be required as estimates are refined based on closure developments, groundwater monitoring results, and regulatory or legal proceedings. Costs relating to this rule are subject to rate recovery. Clean Water Act Regulations under the federal Clean Water Act dictate permitting and mitigation requirements for facilities and construction projects in the United States. Many of those requirements relate to power plant operations, including requirements related to the treatment of pollutants in effluents prior to discharge, the temperature of effluent discharges and the location, design and construction of cooling water intake structures at generating facilities, standards intended to protect aquatic organisms that become trapped at or pulled through cooling water intake structures at generating facilities. The requirements could impose significant costs for LG&E and KU, which are subject to rate recovery. ELGs In September 2015, the EPA released its final ELGs for wastewater discharge permits for new and existing steam electric generating facilities. The rule provides strict technology-based discharge limitations for control of pollutants in scrubber wastewater, fly ash and bottom ash transport water, mercury control wastewater, gasification wastewater and combustion residual leachate. The new guidelines require deployment of additional control technologies providing physical, chemical and biological treatment of wastewaters. The guidelines also mandate operational changes including "no discharge" requirements for fly ash and bottom ash transport waters and mercury control wastewaters. The implementation date for individual generating stations will be determined by the states on a case-by-case basis according to criteria provided by the EPA. Industry groups, environmental groups, individual companies and others have filed legal challenges to the final rule, which have been consolidated before the U.S. Court of Appeals for the Fifth Circuit. In April 2017, the EPA announced that it would grant petitions for reconsideration of the rule. In September 2017, the EPA published in the Federal Register a proposed rule that would postpone the compliance date for requirements relating to bottom ash transport waters and scrubber wastewaters discharge limits. The EPA expects to complete its reconsideration of best available technology standards by the fall of 2020. Upon completion of the ongoing regulatory proceedings, the rule will be implemented by the states in the course of their normal permitting activities. LG&E and KU are developing compliance strategies and schedules. PPL, LKE, LG&E and KU are unable to predict the outcome of the EPA's pending reconsideration of the rule or fully estimate compliance costs or timing. Additionally, certain aspects of these compliance plans and estimates relate to developments in state water quality standards, which are separate from the ELG rule or its implementation. Costs to comply with ELGs or other discharge limits, which are expected to be significant, are subject to rate recovery. Seepages and Groundwater Infiltration Seepages or groundwater infiltration have been detected at active and retired wastewater basins and landfills at various LG&E and KU plants. LG&E and KU have completed, or are completing, assessments of seepages or groundwater infiltration at various facilities and have completed, or are working with agencies to implement, further testing, monitoring or abatement measures, where applicable. A range of reasonably possible costs cannot currently be estimated. Depending on the circumstances in each case, certain costs, which may be subject to rate recovery, could be significant. (All Registrants) Other Issues In June 2016, the "Frank Lautenberg Chemical Safety Act" took effect as an amendment to the Toxic Substance Control Act (TSCA). The Act made no changes to the pre-existing TSCA rules as it pertains to polychlorinated biphenyls (PCB). The EPA continues to reassess its PCB regulations as part of the 2010 Advanced Notice of Proposed Rulemaking (ANPRM). The EPA's ANPRM rulemaking is to occur in two phases. Only the second part of the rule, currently scheduled for November 2017, is applicable to PPL operations. This part of the rule relates to the use of PCBs in electrical equipment and natural gas pipelines, as well as continued use of PCB-contaminated porous surfaces. Although the first rulemaking will not directly affect the Registrants' operations, it may indicate certain approaches or principles to occur in the later rulemaking which may affect Registrants' facilities in the United States, including phase-out of some or all equipment containing PCBs. Should such a phase-out be required, the costs, which are subject to rate recovery, could be significant. Superfund and Other Remediation PPL Electric is potentially responsible for a share of the costs at several sites listed by the EPA under the federal Superfund program, including the Columbia Gas Plant site and the Brodhead site. Clean-up actions have been or are being undertaken at all of these sites, the costs of which have not been, and are not expected to be, significant to PPL Electric. PPL Electric, LG&E and KU are investigating, responding to agency inquiries, taking various measures, remediating, or have completed the remediation of, for several sites that were not addressed under a regulatory program such as Superfund, but for which PPL Electric, LG&E and KU may be liable for remediation. These include a number of former coal gas manufacturing plants in Pennsylvania and Kentucky previously owned or operated or currently owned by predecessors or affiliates of PPL Electric, LG&E and KU. To date, the costs of these sites have not been significant. There are additional sites, formerly owned or operated by PPL Electric, LG&E and KU predecessors or affiliates. PPL Electric, LG&E and KU lack sufficient information on such additional sites and are therefore unable to estimate any potential liability they may have or a range of reasonably possible losses, if any, related to these matters. At December 31, 2017 , PPL Electric had a recorded liability of $10 million representing its best estimate of the probable loss incurred to remediate the sites noted above. Depending on the outcome of investigations at sites where investigations have not begun or been completed, or developments at sites for which information is incomplete, additional costs of remediation could be incurred; however, such costs are not expected to be significant. The EPA is evaluating the risks associated with polycyclic aromatic hydrocarbons and naphthalene, chemical by-products of coal gas manufacturing. As a result of the EPA's evaluation, individual states may establish stricter standards for water quality and soil cleanup. This could require several PPL subsidiaries to take more extensive assessment and remedial actions at former coal gas manufacturing plants. PPL, PPL Electric, LKE, LG&E and KU cannot estimate a range of reasonably possible losses, if any, related to these matters. From time to time, PPL's subsidiaries in the United States undertake testing, monitoring or remedial action in response to notices of violations, spills or other releases at various on-site and off-site locations, negotiate with the EPA and state and local agencies regarding actions necessary for compliance with applicable requirements, negotiate with property owners and other third parties alleging impacts from PPL's operations and undertake similar actions necessary to resolve environmental matters that arise in the course of normal operations. Based on analyses to date, resolution of these environmental matters is not expecte

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
PPL Electric Utilities Corp [Member]
Related Party Transactions [Line Items]
Related Party Transactions	14. Related Party Transactions PLR Contracts/Purchases of Accounts Receivable (PPL Electric) PPL Electric holds competitive solicitations for PLR generation supply. PPL EnergyPlus was awarded a portion of the PLR generation supply through these competitive solicitations. The purchases from PPL EnergyPlus are included in PPL Electric's Statements of Income as "Energy purchases from affiliate" through May 31, 2015, the period through which PPL Electric and PPL EnergyPlus were affiliated entities. As a result of the June 1, 2015 spinoff of PPL Energy Supply and creation of Talen Energy, PPL EnergyPlus (renamed Talen Energy Marketing) is no longer an affiliate of PPL Electric. PPL Electric's purchases from Talen Energy Marketing subsequent to May 31, 2015 are included as purchases from an unaffiliated third party. PPL Electric's customers may choose an alternative supplier for their generation supply. See Note 1 for additional information regarding PPL Electric's purchases of accounts receivable from alternative suppliers, including Talen Energy Marketing. See Note 8 for additional information regarding the spinoff of PPL Energy Supply. Wholesale Sales and Purchases (LG&E and KU) LG&E and KU jointly dispatch their generation units with the lowest cost generation used to serve their retail customers. When LG&E has excess generation capacity after serving its own retail customers and its generation cost is lower than that of KU, KU purchases electricity from LG&E and vice versa. These transactions are reflected in the Statements of Income as "Electric revenue from affiliate" and "Energy purchases from affiliate" and are recorded at a price equal to the seller's fuel cost plus any split savings. Savings realized from such intercompany transactions are shared equally between both companies. The volume of energy each company has to sell to the other is dependent on its retail customers' needs and its available generation. Support Costs (PPL Electric, LKE, LG&E and KU) PPL Services, PPL EU Services and LKS provide PPL, PPL Electric and LKE, their respective subsidiaries, including LG&E and KU, and each other with administrative, management and support services. For all service companies, the costs of these services are charged to the respective recipients as direct support costs. General costs that cannot be directly attributed to a specific entity are allocated and charged to the respective recipients as indirect support costs. PPL Services and PPL EU Services use a three-factor methodology that includes the applicable recipients' invested capital, operation and maintenance expenses and number of employees to allocate indirect costs. PPL Services may also use a ratio of overall direct and indirect costs. LKS bases its indirect allocations on the subsidiaries' number of employees, total assets, revenues, number of customers and/or other statistical information. PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185 In addition to the charges for services noted above, LKS makes payments on behalf of LG&E and KU for fuel purchases and other costs for products or services provided by third parties. LG&E and KU also provide services to each other and to LKS. Billings between LG&E and KU relate to labor and overheads associated with union and hourly employees performing work for the other company, charges related to jointly-owned generating units and other miscellaneous charges. Tax settlements between LKE and LG&E and KU are reimbursed through LKS. Intercompany Borrowings (PPL Electric) PPL Energy Funding maintains a $400 million revolving line of credit with a PPL Electric subsidiary. No balance was outstanding at December 31, 2017 and 2016. The interest rates on borrowings are equal to one-month LIBOR plus a spread. Interest income on the revolving line of credit was not significant for 2017, 2016 or 2015. (LKE) LKE maintains a revolving line of credit with a PPL Energy Funding subsidiary whereby LKE can borrow funds on a short-term basis at market-based rates. In December 2017, the revolving line of credit was increased by $50 million and the limit as of December 31, 2017 was $275 million . The interest rates on borrowings are equal to one-month LIBOR plus a spread. At December 31, 2017 and 2016 , $225 million and $163 million were outstanding and reflected in "Notes payable with affiliates" on the Balance Sheets. The interest rate on the outstanding borrowings at December 31, 2017 and 2016 was 2.87% and 2.12% . Interest expense on the revolving line of credit was not significant for 2017 , 2016 or 2015 . LKE maintains an agreement with a PPL affiliate that has a $300 million borrowing limit whereby LKE can loan funds on a short-term basis at market-based rates. No balance was outstanding at December 31, 2017 and 2016 . The interest rate on the loan based on the PPL affiliates credit rating is currently equal to one-month LIBOR plus a spread. Interest income on this note was not significant for 2017 , 2016 or 2015 . LKE maintains a $400 million ten -year-note with a PPL affiliate with an interest rate of 3.5% . At December 31, 2017 and 2016, the note was reflected in "Long-term debt to affiliate" on the Balance Sheets. Interest expense on this note was $14 million for 2017 and 2016 and not significant for 2015 . (LG&E) LG&E participates in an intercompany money pool agreement whereby LKE and/or KU make available to LG&E funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest expense incurred on the money pool agreement with KU was not significant for 2017 or 2016 . There was no money pool activity with KU in 2015 . (KU) KU participates in an intercompany money pool agreement whereby LKE and/or LG&E make available to KU funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest income incurred on the money pool agreement with LG&E was not significant for 2017 and 2016 . There was no money pool activity with LG&E in 2015 . Intercompany Derivatives (LKE, LG&E and KU) Periodically, LG&E and KU enter into forward-starting interest rate swaps with PPL. These hedging instruments have terms identical to forward-starting swaps entered into by PPL with third parties. Other (PPL Electric, LKE, LG&E and KU) See Note 1 for discussions regarding the intercompany tax sharing agreement (for PPL Electric, LKE, LG&E and KU) and intercompany allocations of stock-based compensation expense (for PPL Electric and LKE). For PPL Electric, LG&E and KU, see Note 11 for discussions regarding intercompany allocations associated with defined benefits.
LG And E And KU Energy LLC [Member]
Related Party Transactions [Line Items]
Related Party Transactions	14. Related Party Transactions PLR Contracts/Purchases of Accounts Receivable (PPL Electric) PPL Electric holds competitive solicitations for PLR generation supply. PPL EnergyPlus was awarded a portion of the PLR generation supply through these competitive solicitations. The purchases from PPL EnergyPlus are included in PPL Electric's Statements of Income as "Energy purchases from affiliate" through May 31, 2015, the period through which PPL Electric and PPL EnergyPlus were affiliated entities. As a result of the June 1, 2015 spinoff of PPL Energy Supply and creation of Talen Energy, PPL EnergyPlus (renamed Talen Energy Marketing) is no longer an affiliate of PPL Electric. PPL Electric's purchases from Talen Energy Marketing subsequent to May 31, 2015 are included as purchases from an unaffiliated third party. PPL Electric's customers may choose an alternative supplier for their generation supply. See Note 1 for additional information regarding PPL Electric's purchases of accounts receivable from alternative suppliers, including Talen Energy Marketing. See Note 8 for additional information regarding the spinoff of PPL Energy Supply. Wholesale Sales and Purchases (LG&E and KU) LG&E and KU jointly dispatch their generation units with the lowest cost generation used to serve their retail customers. When LG&E has excess generation capacity after serving its own retail customers and its generation cost is lower than that of KU, KU purchases electricity from LG&E and vice versa. These transactions are reflected in the Statements of Income as "Electric revenue from affiliate" and "Energy purchases from affiliate" and are recorded at a price equal to the seller's fuel cost plus any split savings. Savings realized from such intercompany transactions are shared equally between both companies. The volume of energy each company has to sell to the other is dependent on its retail customers' needs and its available generation. Support Costs (PPL Electric, LKE, LG&E and KU) PPL Services, PPL EU Services and LKS provide PPL, PPL Electric and LKE, their respective subsidiaries, including LG&E and KU, and each other with administrative, management and support services. For all service companies, the costs of these services are charged to the respective recipients as direct support costs. General costs that cannot be directly attributed to a specific entity are allocated and charged to the respective recipients as indirect support costs. PPL Services and PPL EU Services use a three-factor methodology that includes the applicable recipients' invested capital, operation and maintenance expenses and number of employees to allocate indirect costs. PPL Services may also use a ratio of overall direct and indirect costs. LKS bases its indirect allocations on the subsidiaries' number of employees, total assets, revenues, number of customers and/or other statistical information. PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185 In addition to the charges for services noted above, LKS makes payments on behalf of LG&E and KU for fuel purchases and other costs for products or services provided by third parties. LG&E and KU also provide services to each other and to LKS. Billings between LG&E and KU relate to labor and overheads associated with union and hourly employees performing work for the other company, charges related to jointly-owned generating units and other miscellaneous charges. Tax settlements between LKE and LG&E and KU are reimbursed through LKS. Intercompany Borrowings (PPL Electric) PPL Energy Funding maintains a $400 million revolving line of credit with a PPL Electric subsidiary. No balance was outstanding at December 31, 2017 and 2016. The interest rates on borrowings are equal to one-month LIBOR plus a spread. Interest income on the revolving line of credit was not significant for 2017, 2016 or 2015. (LKE) LKE maintains a revolving line of credit with a PPL Energy Funding subsidiary whereby LKE can borrow funds on a short-term basis at market-based rates. In December 2017, the revolving line of credit was increased by $50 million and the limit as of December 31, 2017 was $275 million . The interest rates on borrowings are equal to one-month LIBOR plus a spread. At December 31, 2017 and 2016 , $225 million and $163 million were outstanding and reflected in "Notes payable with affiliates" on the Balance Sheets. The interest rate on the outstanding borrowings at December 31, 2017 and 2016 was 2.87% and 2.12% . Interest expense on the revolving line of credit was not significant for 2017 , 2016 or 2015 . LKE maintains an agreement with a PPL affiliate that has a $300 million borrowing limit whereby LKE can loan funds on a short-term basis at market-based rates. No balance was outstanding at December 31, 2017 and 2016 . The interest rate on the loan based on the PPL affiliates credit rating is currently equal to one-month LIBOR plus a spread. Interest income on this note was not significant for 2017 , 2016 or 2015 . LKE maintains a $400 million ten -year-note with a PPL affiliate with an interest rate of 3.5% . At December 31, 2017 and 2016, the note was reflected in "Long-term debt to affiliate" on the Balance Sheets. Interest expense on this note was $14 million for 2017 and 2016 and not significant for 2015 . (LG&E) LG&E participates in an intercompany money pool agreement whereby LKE and/or KU make available to LG&E funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest expense incurred on the money pool agreement with KU was not significant for 2017 or 2016 . There was no money pool activity with KU in 2015 . (KU) KU participates in an intercompany money pool agreement whereby LKE and/or LG&E make available to KU funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest income incurred on the money pool agreement with LG&E was not significant for 2017 and 2016 . There was no money pool activity with LG&E in 2015 . Intercompany Derivatives (LKE, LG&E and KU) Periodically, LG&E and KU enter into forward-starting interest rate swaps with PPL. These hedging instruments have terms identical to forward-starting swaps entered into by PPL with third parties. Other (PPL Electric, LKE, LG&E and KU) See Note 1 for discussions regarding the intercompany tax sharing agreement (for PPL Electric, LKE, LG&E and KU) and intercompany allocations of stock-based compensation expense (for PPL Electric and LKE). For PPL Electric, LG&E and KU, see Note 11 for discussions regarding intercompany allocations associated with defined benefits.
Louisville Gas And Electric Co [Member]
Related Party Transactions [Line Items]
Related Party Transactions	14. Related Party Transactions PLR Contracts/Purchases of Accounts Receivable (PPL Electric) PPL Electric holds competitive solicitations for PLR generation supply. PPL EnergyPlus was awarded a portion of the PLR generation supply through these competitive solicitations. The purchases from PPL EnergyPlus are included in PPL Electric's Statements of Income as "Energy purchases from affiliate" through May 31, 2015, the period through which PPL Electric and PPL EnergyPlus were affiliated entities. As a result of the June 1, 2015 spinoff of PPL Energy Supply and creation of Talen Energy, PPL EnergyPlus (renamed Talen Energy Marketing) is no longer an affiliate of PPL Electric. PPL Electric's purchases from Talen Energy Marketing subsequent to May 31, 2015 are included as purchases from an unaffiliated third party. PPL Electric's customers may choose an alternative supplier for their generation supply. See Note 1 for additional information regarding PPL Electric's purchases of accounts receivable from alternative suppliers, including Talen Energy Marketing. See Note 8 for additional information regarding the spinoff of PPL Energy Supply. Wholesale Sales and Purchases (LG&E and KU) LG&E and KU jointly dispatch their generation units with the lowest cost generation used to serve their retail customers. When LG&E has excess generation capacity after serving its own retail customers and its generation cost is lower than that of KU, KU purchases electricity from LG&E and vice versa. These transactions are reflected in the Statements of Income as "Electric revenue from affiliate" and "Energy purchases from affiliate" and are recorded at a price equal to the seller's fuel cost plus any split savings. Savings realized from such intercompany transactions are shared equally between both companies. The volume of energy each company has to sell to the other is dependent on its retail customers' needs and its available generation. Support Costs (PPL Electric, LKE, LG&E and KU) PPL Services, PPL EU Services and LKS provide PPL, PPL Electric and LKE, their respective subsidiaries, including LG&E and KU, and each other with administrative, management and support services. For all service companies, the costs of these services are charged to the respective recipients as direct support costs. General costs that cannot be directly attributed to a specific entity are allocated and charged to the respective recipients as indirect support costs. PPL Services and PPL EU Services use a three-factor methodology that includes the applicable recipients' invested capital, operation and maintenance expenses and number of employees to allocate indirect costs. PPL Services may also use a ratio of overall direct and indirect costs. LKS bases its indirect allocations on the subsidiaries' number of employees, total assets, revenues, number of customers and/or other statistical information. PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185 In addition to the charges for services noted above, LKS makes payments on behalf of LG&E and KU for fuel purchases and other costs for products or services provided by third parties. LG&E and KU also provide services to each other and to LKS. Billings between LG&E and KU relate to labor and overheads associated with union and hourly employees performing work for the other company, charges related to jointly-owned generating units and other miscellaneous charges. Tax settlements between LKE and LG&E and KU are reimbursed through LKS. Intercompany Borrowings (PPL Electric) PPL Energy Funding maintains a $400 million revolving line of credit with a PPL Electric subsidiary. No balance was outstanding at December 31, 2017 and 2016. The interest rates on borrowings are equal to one-month LIBOR plus a spread. Interest income on the revolving line of credit was not significant for 2017, 2016 or 2015. (LKE) LKE maintains a revolving line of credit with a PPL Energy Funding subsidiary whereby LKE can borrow funds on a short-term basis at market-based rates. In December 2017, the revolving line of credit was increased by $50 million and the limit as of December 31, 2017 was $275 million . The interest rates on borrowings are equal to one-month LIBOR plus a spread. At December 31, 2017 and 2016 , $225 million and $163 million were outstanding and reflected in "Notes payable with affiliates" on the Balance Sheets. The interest rate on the outstanding borrowings at December 31, 2017 and 2016 was 2.87% and 2.12% . Interest expense on the revolving line of credit was not significant for 2017 , 2016 or 2015 . LKE maintains an agreement with a PPL affiliate that has a $300 million borrowing limit whereby LKE can loan funds on a short-term basis at market-based rates. No balance was outstanding at December 31, 2017 and 2016 . The interest rate on the loan based on the PPL affiliates credit rating is currently equal to one-month LIBOR plus a spread. Interest income on this note was not significant for 2017 , 2016 or 2015 . LKE maintains a $400 million ten -year-note with a PPL affiliate with an interest rate of 3.5% . At December 31, 2017 and 2016, the note was reflected in "Long-term debt to affiliate" on the Balance Sheets. Interest expense on this note was $14 million for 2017 and 2016 and not significant for 2015 . (LG&E) LG&E participates in an intercompany money pool agreement whereby LKE and/or KU make available to LG&E funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest expense incurred on the money pool agreement with KU was not significant for 2017 or 2016 . There was no money pool activity with KU in 2015 . (KU) KU participates in an intercompany money pool agreement whereby LKE and/or LG&E make available to KU funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest income incurred on the money pool agreement with LG&E was not significant for 2017 and 2016 . There was no money pool activity with LG&E in 2015 . Intercompany Derivatives (LKE, LG&E and KU) Periodically, LG&E and KU enter into forward-starting interest rate swaps with PPL. These hedging instruments have terms identical to forward-starting swaps entered into by PPL with third parties. Other (PPL Electric, LKE, LG&E and KU) See Note 1 for discussions regarding the intercompany tax sharing agreement (for PPL Electric, LKE, LG&E and KU) and intercompany allocations of stock-based compensation expense (for PPL Electric and LKE). For PPL Electric, LG&E and KU, see Note 11 for discussions regarding intercompany allocations associated with defined benefits.
Kentucky Utilities Co [Member]
Related Party Transactions [Line Items]
Related Party Transactions	14. Related Party Transactions PLR Contracts/Purchases of Accounts Receivable (PPL Electric) PPL Electric holds competitive solicitations for PLR generation supply. PPL EnergyPlus was awarded a portion of the PLR generation supply through these competitive solicitations. The purchases from PPL EnergyPlus are included in PPL Electric's Statements of Income as "Energy purchases from affiliate" through May 31, 2015, the period through which PPL Electric and PPL EnergyPlus were affiliated entities. As a result of the June 1, 2015 spinoff of PPL Energy Supply and creation of Talen Energy, PPL EnergyPlus (renamed Talen Energy Marketing) is no longer an affiliate of PPL Electric. PPL Electric's purchases from Talen Energy Marketing subsequent to May 31, 2015 are included as purchases from an unaffiliated third party. PPL Electric's customers may choose an alternative supplier for their generation supply. See Note 1 for additional information regarding PPL Electric's purchases of accounts receivable from alternative suppliers, including Talen Energy Marketing. See Note 8 for additional information regarding the spinoff of PPL Energy Supply. Wholesale Sales and Purchases (LG&E and KU) LG&E and KU jointly dispatch their generation units with the lowest cost generation used to serve their retail customers. When LG&E has excess generation capacity after serving its own retail customers and its generation cost is lower than that of KU, KU purchases electricity from LG&E and vice versa. These transactions are reflected in the Statements of Income as "Electric revenue from affiliate" and "Energy purchases from affiliate" and are recorded at a price equal to the seller's fuel cost plus any split savings. Savings realized from such intercompany transactions are shared equally between both companies. The volume of energy each company has to sell to the other is dependent on its retail customers' needs and its available generation. Support Costs (PPL Electric, LKE, LG&E and KU) PPL Services, PPL EU Services and LKS provide PPL, PPL Electric and LKE, their respective subsidiaries, including LG&E and KU, and each other with administrative, management and support services. For all service companies, the costs of these services are charged to the respective recipients as direct support costs. General costs that cannot be directly attributed to a specific entity are allocated and charged to the respective recipients as indirect support costs. PPL Services and PPL EU Services use a three-factor methodology that includes the applicable recipients' invested capital, operation and maintenance expenses and number of employees to allocate indirect costs. PPL Services may also use a ratio of overall direct and indirect costs. LKS bases its indirect allocations on the subsidiaries' number of employees, total assets, revenues, number of customers and/or other statistical information. PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185 In addition to the charges for services noted above, LKS makes payments on behalf of LG&E and KU for fuel purchases and other costs for products or services provided by third parties. LG&E and KU also provide services to each other and to LKS. Billings between LG&E and KU relate to labor and overheads associated with union and hourly employees performing work for the other company, charges related to jointly-owned generating units and other miscellaneous charges. Tax settlements between LKE and LG&E and KU are reimbursed through LKS. Intercompany Borrowings (PPL Electric) PPL Energy Funding maintains a $400 million revolving line of credit with a PPL Electric subsidiary. No balance was outstanding at December 31, 2017 and 2016. The interest rates on borrowings are equal to one-month LIBOR plus a spread. Interest income on the revolving line of credit was not significant for 2017, 2016 or 2015. (LKE) LKE maintains a revolving line of credit with a PPL Energy Funding subsidiary whereby LKE can borrow funds on a short-term basis at market-based rates. In December 2017, the revolving line of credit was increased by $50 million and the limit as of December 31, 2017 was $275 million . The interest rates on borrowings are equal to one-month LIBOR plus a spread. At December 31, 2017 and 2016 , $225 million and $163 million were outstanding and reflected in "Notes payable with affiliates" on the Balance Sheets. The interest rate on the outstanding borrowings at December 31, 2017 and 2016 was 2.87% and 2.12% . Interest expense on the revolving line of credit was not significant for 2017 , 2016 or 2015 . LKE maintains an agreement with a PPL affiliate that has a $300 million borrowing limit whereby LKE can loan funds on a short-term basis at market-based rates. No balance was outstanding at December 31, 2017 and 2016 . The interest rate on the loan based on the PPL affiliates credit rating is currently equal to one-month LIBOR plus a spread. Interest income on this note was not significant for 2017 , 2016 or 2015 . LKE maintains a $400 million ten -year-note with a PPL affiliate with an interest rate of 3.5% . At December 31, 2017 and 2016, the note was reflected in "Long-term debt to affiliate" on the Balance Sheets. Interest expense on this note was $14 million for 2017 and 2016 and not significant for 2015 . (LG&E) LG&E participates in an intercompany money pool agreement whereby LKE and/or KU make available to LG&E funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest expense incurred on the money pool agreement with KU was not significant for 2017 or 2016 . There was no money pool activity with KU in 2015 . (KU) KU participates in an intercompany money pool agreement whereby LKE and/or LG&E make available to KU funds up to $500 million at an interest rate based on a market index of commercial paper issues. No balances were outstanding at December 31, 2017 and 2016 . Interest income incurred on the money pool agreement with LG&E was not significant for 2017 and 2016 . There was no money pool activity with LG&E in 2015 . Intercompany Derivatives (LKE, LG&E and KU) Periodically, LG&E and KU enter into forward-starting interest rate swaps with PPL. These hedging instruments have terms identical to forward-starting swaps entered into by PPL with third parties. Other (PPL Electric, LKE, LG&E and KU) See Note 1 for discussions regarding the intercompany tax sharing agreement (for PPL Electric, LKE, LG&E and KU) and intercompany allocations of stock-based compensation expense (for PPL Electric and LKE). For PPL Electric, LG&E and KU, see Note 11 for discussions regarding intercompany allocations associated with defined benefits.

Other Income (Expense) - net

Other Income (Expense) - net	12 Months Ended
	Dec. 31, 2017
Other Nonoperating Income (Expense) [Abstract]
Other Income (Expense) - net	15. Other Income (Expense) - net (PPL) The breakdown of "Other Income (Expense) - net" for the years ended December 31, was: 2017 2016 2015 Other Income Economic foreign currency exchange contracts (Note 17) $ (261 ) $ 384 $ 122 Interest income 2 3 4 AFUDC - equity component 16 19 14 Miscellaneous 17 6 6 Total Other Income (226 ) 412 146 Other Expense Charitable contributions 8 9 21 Miscellaneous 21 13 17 Total Other Expense 29 22 38 Other Income (Expense) - net $ (255 ) $ 390 $ 108

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements and Credit Concentration	16. Fair Value Measurements (All Registrants) Fair value is 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 (an exit price). A market approach (generally, data from market transactions), an income approach (generally, present value techniques and option-pricing models), and/or a cost approach (generally, replacement cost) are used to measure the fair value of an asset or liability, as appropriate. These valuation approaches incorporate inputs such as observable, independent market data and/or unobservable data that management believes are predicated on the assumptions market participants would use to price an asset or liability. These inputs may incorporate, as applicable, certain risks such as nonperformance risk, which includes credit risk. The fair value of a group of financial assets and liabilities is measured on a net basis. Transfers between levels are recognized at end-of-reporting-period values. During 2017 and 2016 , there were no transfers between Level 1 and Level 2. See Note 1 for information on the levels in the fair value hierarchy. Recurring Fair Value Measurements The assets and liabilities measured at fair value were: December 31, 2017 December 31, 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 PPL Assets Cash and cash equivalents $ 485 $ 485 $ — $ — $ 341 $ 341 $ — $ — Restricted cash and cash equivalents (a) 26 26 — — 26 26 — — Price risk management assets (b): Foreign currency contracts 163 — 163 — 211 — 211 — Cross-currency swaps 101 — 101 — 188 — 188 — Total price risk management assets 264 — 264 — 399 — 399 — Total assets $ 775 $ 511 $ 264 $ — $ 766 $ 367 $ 399 $ — December 31, 2017 December 31, 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Liabilities Price risk management liabilities (b): Interest rate swaps $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — Foreign currency contracts 148 — 148 — 27 — 27 — Total price risk management liabilities $ 174 $ — $ 174 $ — $ 58 $ — $ 58 $ — PPL Electric Assets Cash and cash equivalents $ 49 $ 49 $ — $ — $ 13 $ 13 $ — $ — Restricted cash and cash equivalents (a) 2 2 — — 2 2 — — Total assets $ 51 $ 51 $ — $ — $ 15 $ 15 $ — $ — LKE Assets Cash and cash equivalents $ 30 $ 30 $ — $ — $ 13 $ 13 $ — $ — Cash collateral posted to counterparties (c) — — — — 3 3 — — Total assets $ 30 $ 30 $ — $ — $ 16 $ 16 $ — $ — Liabilities Price risk management liabilities: Interest rate swaps $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — Total price risk management liabilities $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — LG&E Assets Cash and cash equivalents $ 15 $ 15 $ — $ — $ 5 $ 5 $ — $ — Cash collateral posted to counterparties (c) — — — — 3 3 — — Total assets $ 15 $ 15 $ — $ — $ 8 $ 8 $ — $ — Liabilities Price risk management liabilities: Interest rate swaps $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — Total price risk management liabilities $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — KU Assets Cash and cash equivalents $ 15 $ 15 $ — $ — $ 7 $ 7 $ — $ — Total assets $ 15 $ 15 $ — $ — $ 7 $ 7 $ — $ — (a) Current portion is included in "Other current assets" and long-term portion is included in "Other noncurrent assets" on the Balance Sheets. (b) Current portion is included in "Price risk management assets" and "Other current liabilities" and noncurrent portion is included in "Price risk management assets" and "Other deferred credits and noncurrent liabilities" on the Balance Sheets. (c) Included in "Other noncurrent assets" on the Balance Sheets. Represents cash collateral posted to offset the exposure with counterparties related to certain interest rate swaps under master netting arrangements that are not offset. Price Risk Management Assets/Liabilities - Interest Rate Swaps/Foreign Currency Contracts/Cross-Currency Swaps (PPL, LKE, LG&E and KU) To manage interest rate risk, PPL, LKE, LG&E and KU use interest rate contracts such as forward-starting swaps, floating-to-fixed swaps and fixed-to-floating swaps. To manage foreign currency exchange risk, PPL uses foreign currency contracts such as forwards, options, and cross-currency swaps that contain characteristics of both interest rate and foreign currency contracts. An income approach is used to measure the fair value of these contracts, utilizing readily observable inputs, such as forward interest rates (e.g., LIBOR and government security rates) and forward foreign currency exchange rates (e.g., GBP), as well as inputs that may not be observable, such as credit valuation adjustments. In certain cases, market information cannot practicably be obtained to value credit risk and therefore internal models are relied upon. These models use projected probabilities of default and estimated recovery rates based on historical observances. When the credit valuation adjustment is significant to the overall valuation, the contracts are classified as Level 3. Nonrecurring Fair Value Measurements (PPL) See Note 8 for information regarding the estimated fair value of the Supply segment's net assets as of the June 1, 2015 spinoff date. Financial Instruments Not Recorded at Fair Value (All Registrants) The carrying amounts of long-term debt on the Balance Sheets and their estimated fair values are set forth below. The fair values were estimated using an income approach by discounting future cash flows at estimated current cost of funding rates, which incorporate the credit risk of the Registrants. Long-term debt is classified as Level 2. The effect of third-party credit enhancements is not included in the fair value measurement. December 31, 2017 December 31, 2016 Carrying Fair Value Carrying Fair Value PPL $ 20,195 $ 23,783 $ 18,326 $ 21,355 PPL Electric 3,298 3,769 2,831 3,148 LKE 5,159 5,670 5,065 5,439 LG&E 1,709 1,865 1,617 1,710 KU 2,328 2,605 2,327 2,514 (a) Amounts are net of debt issuance costs. The carrying amounts of other current financial instruments (except for long-term debt due within one year) approximate their fair values because of their short-term nature.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	17. Derivative Instruments and Hedging Activities Risk Management Objectives (All Registrants) PPL has a risk management policy approved by the Board of Directors to manage market risk associated with commodities, interest rates on debt issuances and foreign exchange (including price, liquidity and volumetric risk) and credit risk (including non-performance risk and payment default risk). The Risk Management Committee, comprised of senior management and chaired by the Senior Director-Risk Management, oversees the risk management function. Key risk control activities designed to ensure compliance with the risk policy and detailed programs include, but are not limited to, credit review and approval, validation of transactions, verification of risk and transaction limits, value-at-risk analyses (VaR, a statistical model that attempts to estimate the value of potential loss over a given holding period under normal market conditions at a given confidence level) and the coordination and reporting of the Enterprise Risk Management program. Market Risk Market risk includes the potential loss that may be incurred as a result of price changes associated with a particular financial or commodity instrument as well as market liquidity and volumetric risks. Forward contracts, futures contracts, options, swaps and structured transactions are utilized as part of risk management strategies to minimize unanticipated fluctuations in earnings caused by changes in commodity prices, interest rates and foreign currency exchange rates. Many of these contracts meet the definition of a derivative. All derivatives are recognized on the Balance Sheets at their fair value, unless NPNS is elected. The following summarizes the market risks that affect PPL and its subsidiaries. Interest Rate Risk • PPL and its subsidiaries are exposed to interest rate risk associated with forecasted fixed-rate and existing floating-rate debt issuances. PPL and WPD hold over-the-counter cross currency swaps to limit exposure to market fluctuations on interest and principal payments from changes in foreign currency exchange rates and interest rates. PPL, LKE and LG&E utilize over-the-counter interest rate swaps to limit exposure to market fluctuations on floating-rate debt. PPL, LKE, LG&E and KU utilize forward starting interest rate swaps to hedge changes in benchmark interest rates, when appropriate, in connection with future debt issuances. • PPL and its subsidiaries are exposed to interest rate risk associated with debt securities and derivatives held by defined benefit plans. This risk is significantly mitigated to the extent that the plans are sponsored at, or sponsored on behalf of, the regulated domestic utilities and for certain plans at WPD due to the recovery methods in place. Foreign Currency Risk (PPL) • PPL is exposed to foreign currency exchange risk primarily associated with its investments in and earnings of U.K. affiliates. (All Registrants) Commodity Price Risk PPL is exposed to commodity price risk through its domestic subsidiaries as described below. • PPL Electric is required to purchase electricity to fulfill its obligation as a PLR. Potential commodity price risk is mitigated through its PUC-approved cost recovery mechanism and full-requirement supply agreements to serve its PLR customers which transfer the risk to energy suppliers. • LG&E's and KU's rates include certain mechanisms for fuel, fuel-related expenses and energy purchases. In addition, LG&E's rates include a mechanism for natural gas supply expenses. These mechanisms generally provide for timely recovery of market price fluctuations associated with these expenses. Volumetric Risk PPL is exposed to volumetric risk through its subsidiaries as described below. • WPD is exposed to volumetric risk which is significantly mitigated as a result of the method of regulation in the U.K. Under the RIIO-ED1 price control regulations, recovery of such exposure occurs on a two year lag. See Note 1 for additional information on revenue recognition under RIIO-ED1. • PPL Electric, LG&E and KU are exposed to volumetric risk on retail sales, mainly due to weather and other economic conditions for which there is limited mitigation between rate cases. Equity Securities Price Risk • PPL and its subsidiaries are exposed to equity securities price risk associated with the fair value of the defined benefit plans' assets. This risk is significantly mitigated at the regulated domestic utilities and for certain plans at WPD due to the recovery methods in place. • PPL is exposed to equity securities price risk from future stock sales and/or purchases. Credit Risk Credit risk is the potential loss that may be incurred due to a counterparty's non-performance. PPL is exposed to credit risk from "in-the-money" interest rate and foreign currency derivatives with financial institutions, as well as additional credit risk through certain of its subsidiaries, as discussed below. In the event a supplier of PPL Electric, LG&E or KU defaults on its obligation, those Registrants would be required to seek replacement power or replacement fuel in the market. In general, subject to regulatory review or other processes, appropriate incremental costs incurred by these entities would be recoverable from customers through applicable rate mechanisms, thereby mitigating the financial risk for these entities. PPL and its subsidiaries have credit policies in place to manage credit risk, including the use of an established credit approval process, daily monitoring of counterparty positions and the use of master netting agreements or provisions. These agreements generally include credit mitigation provisions, such as margin, prepayment or collateral requirements. PPL and its subsidiaries may request additional credit assurance, in certain circumstances, in the event that the counterparties' credit ratings fall below investment grade, their tangible net worth falls below specified percentages or their exposures exceed an established credit limit. Master Netting Arrangements (PPL, LKE, LG&E and KU) Net derivative positions on the balance sheets are not offset against the right to reclaim cash collateral (a receivable) or the obligation to return cash collateral (a payable) under master netting arrangements. PPL had a $20 million and $19 million obligation to return cash collateral under master netting arrangements at December 31, 2017 and 2016 . LKE, LG&E and KU had no obligation to return cash collateral under master netting arrangements at December 31, 2017 and 2016 . PPL, LKE, and LG&E had no cash collateral posted under master netting arrangements at December 31, 2017 . PPL, LKE and LG&E posted $3 million of cash collateral under master netting arrangements at December 31, 2016 . KU did not post any cash collateral under master netting arrangements at December 31, 2017 and 2016 . See "Offsetting Derivative Instruments" below for a summary of derivative positions presented in the balance sheets where a right of setoff exists under these arrangements. Interest Rate Risk (All Registrants) PPL and its subsidiaries issue debt to finance their operations, which exposes them to interest rate risk. A variety of financial derivative instruments are utilized to adjust the mix of fixed and floating interest rates in their debt portfolios, adjust the duration of the debt portfolios and lock in benchmark interest rates in anticipation of future financing, when appropriate. Risk limits under PPL's risk management program are designed to balance risk exposure to volatility in interest expense and changes in the fair value of the debt portfolio due to changes in benchmark interest rates. In addition, the interest rate risk of certain subsidiaries is potentially mitigated as a result of the existing regulatory framework or the timing of rate cases. Cash Flow Hedges (PPL) Interest rate risks include exposure to adverse interest rate movements for outstanding variable rate debt and for future anticipated financings. Financial interest rate swap contracts that qualify as cash flow hedges may be entered into to hedge floating interest rate risk associated with both existing and anticipated debt issuances. PPL held no such contracts at December 31, 2017. For 2017, PPL had no hedge ineffectiveness associated with interest rate derivatives. For 2016 and 2015, hedge ineffectiveness associated with interest rate derivatives was insignificant. At December 31, 2017 , PPL held an aggregate notional value in cross-currency interest rate swap contracts of $702 million that range in maturity from 2021 through 2028 to hedge the interest payments and principal of WPD's U.S. dollar-denominated senior notes. In December 2017, $100 million of WPD’s U.S. dollar-denominated senior notes were repaid upon maturity and $100 million notional value of cross-currency interest rate swap contracts matured. PPL recorded a $19 million gain upon settlement of the cross-currency interest rate swap contracts, which largely offset a loss recorded on the revaluation of U.S. dollar-denominated senior notes. Cash flow hedges are discontinued if it is no longer probable that the original forecasted transaction will occur by the end of the originally specified time period and any amounts previously recorded in AOCI are reclassified into earnings once it is determined that the hedged transaction is not probable of occurring. PPL had an insignificant amount of cash flow hedges reclassified into earnings associated with discontinued cash flow hedges in 2017 and 2016. As a result of the June 1, 2015 spinoff of PPL Energy Supply, all PPL cash flow hedges associated with PPL Energy Supply were ineffective and discontinued and therefore, reclassified into earnings during the second quarter of 2015 and reflected in discontinued operations for 2015. See Note 8 for additional information. PPL had no other cash flow hedges reclassified into earnings associated with discontinued cash flow hedges in 2015. At December 31, 2017 , the accumulated net unrecognized after-tax gains (losses) on qualifying derivatives expected to be reclassified into earnings during the next 12 months is insignificant. Amounts are reclassified as the hedged interest expense is recorded. Economic Activity (PPL, LKE and LG&E) LG&E enters into interest rate swap contracts that economically hedge interest payments on variable rate debt. Because realized gains and losses from the swaps, including terminated swap contracts, are recoverable through regulated rates, any subsequent changes in fair value of these derivatives are included in regulatory assets or liabilities until they are realized as interest expense. Realized gains and losses are recognized in "Interest Expense" on the Statements of Income at the time the underlying hedged interest expense is recorded. In December 2016, a swap with a notional amount of $32 million was terminated. A cash settlement of $9 million was paid on the terminated swap. The settlement is included in noncurrent regulatory assets on the Balance Sheet and in "Cash Flows from Operating Activities" on the Statement of Cash Flows. At December 31, 2017 , LG&E held contracts with a notional amount of $147 million that range in maturity through 2033 . Foreign Currency Risk (PPL) PPL is exposed to foreign currency risk, primarily through investments in and earnings of U.K. affiliates. PPL has adopted a foreign currency risk management program designed to hedge certain foreign currency exposures, including firm commitments, recognized assets or liabilities, anticipated transactions and net investments. In addition, PPL enters into financial instruments to protect against foreign currency translation risk of expected GBP earnings. Net Investment Hedges PPL enters into foreign currency contracts on behalf of a subsidiary to protect the value of a portion of its net investment in WPD. There were no contracts outstanding at December 31, 2017 . At December 31, 2017 and 2016 , PPL had $22 million and $21 million of accumulated net investment hedge after tax gains (losses) that were included in the foreign currency translation adjustment component of AOCI. Economic Activity PPL enters into foreign currency contracts on behalf of a subsidiary to economically hedge GBP-denominated anticipated earnings. At December 31, 2017 , the total exposure hedged by PPL was approximately £2.6 billion (approximately $3.5 billion based on contracted rates). These contracts had termination dates ranging from January 2018 through June 2020 . In the third quarter of 2016, PPL settled foreign currency hedges related to 2017 and 2018 anticipated earnings, resulting in receipt of $310 million of cash and entered into new hedges at current market rates. The notional amount of the settled hedges was approximately £1.3 billion (approximately $2.0 billion based on contracted rates) with termination dates from January 2017 through November 2018 . The settlement did not have a significant impact on net income as the hedge values were previously marked to fair value and recognized in "Other Income (Expense) - net" on the Statement of Income. Accounting and Reporting (All Registrants) All derivative instruments are recorded at fair value on the Balance Sheet as an asset or liability unless NPNS is elected. NPNS contracts for PPL and PPL Electric include certain full-requirement purchase contracts and other physical purchase contracts. Changes in the fair value of derivatives not designated as NPNS are recognized in earnings unless specific hedge accounting criteria are met and designated as such, except for the changes in fair values of LG&E's interest rate swaps that are recognized as regulatory assets or regulatory liabilities. See Note 6 for amounts recorded in regulatory assets and regulatory liabilities at December 31, 2017 and 2016 . See Note 1 for additional information on accounting policies related to derivative instruments. (PPL) The following table presents the fair value and location of derivative instruments recorded on the Balance Sheets. December 31, 2017 December 31, 2016 Derivatives designated as hedging instruments Derivatives not designated as hedging instruments Derivatives designated as hedging instruments Derivatives not designated as hedging instruments Assets Liabilities Assets Liabilities Assets Liabilities Assets Liabilities Current: Price Risk Management Assets/Liabilities (a): Interest rate swaps (b) $ — $ — $ — $ 4 $ — $ — $ — $ 4 Cross-currency swaps (b) 4 — — — 32 — — — Foreign currency contracts — — 45 67 — — 31 21 Total current 4 — 45 71 32 — 31 25 Noncurrent: Price Risk Management Assets/Liabilities (a): Interest rate swaps (b) — — — 22 — — — 27 Cross-currency swaps (b) 97 — — — 156 — — — Foreign currency contracts — — 118 81 — — 180 6 Total noncurrent 97 — 118 103 156 — 180 33 Total derivatives $ 101 $ — $ 163 $ 174 $ 188 $ — $ 211 $ 58 (a) Current portion is included in "Price risk management assets" and "Other current liabilities" and noncurrent portion is included in "Price risk management assets" and "Other deferred credits and noncurrent liabilities" on the Balance Sheets. (b) Excludes accrued interest, if applicable. The following tables present the pre-tax effect of derivative instruments recognized in income, OCI or regulatory assets and regulatory liabilities. Derivative Relationships Derivative Gain (Loss) Recognized in OCI (Effective Portion) Location of Gain (Loss) Recognized in Income on Derivative Gain (Loss) Reclassified from AOCI into Income (Effective Portion) Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) 2017 Cash Flow Hedges: Interest rate swaps $ — Interest Expense $ (9 ) $ — Cross-currency swaps (98 ) Other Income (Expense) - net (82 ) — Total $ (98 ) $ (91 ) $ — Net Investment Hedges: Foreign currency contracts $ 1 2016 Cash Flow Hedges: Interest rate swaps $ (21 ) Interest Expense $ (7 ) $ — Cross-currency swaps 130 Other Income (Expense) - net 116 — Interest Expense 3 — Total $ 109 $ 112 $ — Net Investment Hedges: Foreign currency contracts $ 2 Derivative Relationships Derivative Gain (Loss) Recognized in OCI (Effective Portion) Location of Gain (Loss) Recognized in Income on Derivative Gain (Loss) Reclassified from AOCI into Income (Effective Portion) Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) 2015 Cash Flow Hedges: Interest rate swaps $ (34 ) Interest Expense $ (11 ) $ — Discontinued operations — (77 ) Cross-currency swaps 60 Other Income (Expense) - net 49 — Interest Expense 2 — Commodity contracts Discontinued operations 13 7 Total $ 26 $ 53 $ (70 ) Net Investment Hedges: Foreign currency contracts $ 9 Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative 2017 2016 2015 Foreign currency contracts Other Income (Expense) - net $ (261 ) $ 384 $ 122 Interest rate swaps Interest Expense (6 ) (7 ) (8 ) Total $ (267 ) $ 377 $ 114 Derivatives Designated as Hedging Instruments Location of Gain (Loss) Recognized as Regulatory Liabilities/Assets 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ — $ — $ (22 ) Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized as Regulatory Liabilities/Assets 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ 5 $ 7 $ 1 (LKE) The following table presents the pre-tax effect of derivative instruments designated as cash flow hedges that are recognized in regulatory assets. All derivative instruments designated as cash flow hedges were terminated in 2015 and there is no activity in the current period. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ — $ — $ (22 ) (LG&E) The following table presents the pre-tax effect of derivative instruments designated as cash flow hedges that are recognized in regulatory assets. All derivative instruments designated as cash flow hedges were terminated in 2015 and there is no activity in the current period. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory asset - noncurrent $ — $ — $ (11 ) (KU) The following table presents the pre-tax effect of derivative instruments designated as cash flow hedges that are recognized in regulatory assets. All derivative instruments designated as cash flow hedges were terminated in 2015 and there is no activity in the current period. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ — $ — $ (11 ) (LKE and LG&E) The following table presents the fair value and the location on the Balance Sheets of derivatives not designated as hedging instruments. December 31, 2017 December 31, 2016 Assets Liabilities Assets Liabilities Current: Price Risk Management Assets/Liabilities: Interest rate swaps $ — $ 4 $ — $ 4 Total current — 4 — 4 Noncurrent: Price Risk Management Assets/Liabilities: Interest rate swaps — 22 — 27 Total noncurrent — 22 — 27 Total derivatives $ — $ 26 $ — $ 31 The following tables present the pre-tax effect of derivatives not designated as cash flow hedges that are recognized in income or regulatory assets. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Interest Expense $ (6 ) $ (7 ) $ (8 ) Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ 5 $ 7 $ 1 (PPL, LKE, LG&E and KU) Offsetting Derivative Instruments PPL, LKE, LG&E and KU or certain of their subsidiaries have master netting arrangements in place and also enter into agreements pursuant to which they purchase or sell certain energy and other products. Under the agreements, upon termination of the agreement as a result of a default or other termination event, the non-defaulting party typically would have a right to set off amounts owed under the agreement against any other obligations arising between the two parties (whether under the agreement or not), whether matured or contingent and irrespective of the currency, place of payment or place of booking of the obligation. PPL, LKE, LG&E and KU have elected not to offset derivative assets and liabilities and not to offset net derivative positions against the right to reclaim cash collateral pledged (an asset) or the obligation to return cash collateral received (a liability) under derivatives agreements. The table below summarizes the derivative positions presented in the balance sheets where a right of setoff exists under these arrangements and related cash collateral received or pledged. Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2017 Treasury Derivatives PPL $ 264 $ 107 $ 20 $ 137 $ 174 $ 107 $ — $ 67 LKE — — — — 26 — — 26 LG&E — — — — 26 — — 26 Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2016 Treasury Derivatives PPL $ 399 $ 27 $ 19 $ 353 $ 58 $ 27 $ 3 $ 28 LKE — — — — 31 — 3 28 LG&E — — — — 31 — 3 28 Credit Risk-Related Contingent Features Certain derivative contracts contain credit risk-related contingent features, which when in a net liability position, would permit the counterparties to require the transfer of additional collateral upon a decrease in the credit ratings of PPL, LKE, LG&E and KU or certain of their subsidiaries. Most of these features would require the transfer of additional collateral or permit the counterparty to terminate the contract if the applicable credit rating were to fall below investment grade. Some of these features also would allow the counterparty to require additional collateral upon each downgrade in credit rating at levels that remain above investment grade. In either case, if the applicable credit rating were to fall below investment grade, and assuming no assignment to an investment grade affiliate were allowed, most of these credit contingent features require either immediate payment of the net liability as a termination payment or immediate and ongoing full collateralization on derivative instruments in net liability positions. Additionally, certain derivative contracts contain credit risk-related contingent features that require adequate assurance of performance be provided if the other party has reasonable concerns regarding the performance of PPL's, LKE's, LG&E's and KU's obligations under the contracts. A counterparty demanding adequate assurance could require a transfer of additional collateral or other security, including letters of credit, cash and guarantees from a creditworthy entity. This would typically involve negotiations among the parties. However, amounts disclosed below represent assumed immediate payment or immediate and ongoing full collateralization for derivative instruments in net liability positions with "adequate assurance" features. (PPL, LKE and LG&E) At December 31, 2017 , derivative contracts in a net liability position that contain credit risk-related contingent features, collateral posted on those positions and the related effect of a decrease in credit ratings below investment grade are summarized as follows: PPL LKE LG&E Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features $ 51 $ 10 $ 10 Aggregate fair value of collateral posted on these derivative instruments — — — Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade (a) 51 10 10 (a) Includes the effect of net receivables and payables already recorded on the Balance Sheet.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	18. Goodwill and Other Intangible Assets Goodwill (PPL) The changes in the carrying amount of goodwill by segment were: U.K. Regulated Kentucky Regulated Total 2017 2016 2017 2016 2017 2016 Balance at beginning of period (a) $ 2,398 $ 2,888 $ 662 $ 662 $ 3,060 $ 3,550 Effect of foreign currency exchange rates 198 (490 ) 198 (490 ) Balance at end of period (a) $ 2,596 $ 2,398 $ 662 $ 662 $ 3,258 $ 3,060 (a) There were no accumulated impairment losses related to goodwill. Other Intangible Assets (PPL) The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Contracts (a) $ 138 $ 67 $ 405 $ 325 Land and transmission rights 382 120 362 115 Emission allowances/RECs (b) 1 — 2 — Licenses and other 7 3 6 2 Total subject to amortization 528 190 775 442 Not subject to amortization due to indefinite life: Land and transmission rights 12 — 19 — Easements 347 — 348 — Total not subject to amortization due to indefinite life 359 — 367 — Total $ 887 $ 190 $ 1,142 $ 442 (a) Gross carrying amount in 2017 and 2016 includes the fair value at the acquisition date of the OVEC power purchase contract with terms favorable to market recognized as a result of the 2010 acquisition of LKE by PPL. Gross carrying amount in 2016 also includes the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition of LKE by PPL. At December 31, 2016, these coal contracts were fully amortized. Offsetting regulatory liabilities were recorded related to these contracts, which are being amortized over the same period as the intangible assets, eliminating any income statement impact. This is referred to as "regulatory offset" in the tables below. See Note 6 for additional information. (b) Emission allowances/RECs are expensed when consumed or sold; therefore, there is no accumulated amortization. Current intangible assets are included in "Other current assets" and long-term intangible assets are included in "Other intangibles" on the Balance Sheets. Amortization Expense was as follows: 2017 2016 2015 Intangible assets with no regulatory offset $ 6 $ 6 $ 6 Intangible assets with regulatory offset 9 24 51 Total $ 15 $ 30 $ 57 Amortization expense for each of the next five years, excluding insignificant amounts for consumption of emission allowances/RECs, is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with no regulatory offset $ 6 $ 6 $ 6 $ 6 $ 6 Intangible assets with regulatory offset 9 9 8 8 8 Total $ 15 $ 15 $ 14 $ 14 $ 14 (PPL Electric) The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Land and transmission rights $ 361 $ 117 $ 341 $ 112 Licenses and other 3 1 3 1 Total subject to amortization 364 118 344 113 Not subject to amortization due to indefinite life: Land and transmission rights 13 — 20 — Total $ 377 $ 118 $ 364 $ 113 Intangible assets are shown as "Intangibles" on the Balance Sheets. Amortization expense was insignificant in 2017 , 2016 and 2015 and is expected to be insignificant in future years. (LKE) The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Coal contracts (a) $ — $ — $ 269 $ 269 Land and transmission rights 21 3 21 3 OVEC power purchase agreement (b) 126 58 126 49 Total subject to amortization $ 147 $ 61 $ 416 $ 321 (a) Gross carrying amount represents the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to these contracts, which was amortized over the same period as the intangible asset, eliminating any income statement impact. (b) Gross carrying amount represents the fair value at the acquisition date of the OVEC power purchase contract recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to this contract, which is being amortized over the same period as the intangible asset, eliminating any income statement impact. See Note 6 for additional information. Long-term intangible assets are presented as "Other intangibles" on the Balance Sheets. Amortization expense was as follows: 2017 2016 2015 Intangible assets with no regulatory offset $ — $ 1 $ — Intangible assets with regulatory offset 9 24 51 Total $ 9 $ 25 $ 51 Amortization expense for each of the next five years is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with regulatory offset $ 9 $ 9 $ 8 $ 8 $ 8 (LG&E) The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Coal contracts (a) $ — $ — $ 124 $ 124 Land and transmission rights 7 1 7 1 OVEC power purchase agreement (b) 87 40 87 34 Total subject to amortization $ 94 $ 41 $ 218 $ 159 (a) Gross carrying amount represents the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to these contracts, which was amortized over the same period as the intangible asset, eliminating any income statement impact. (b) Gross carrying amount represents the fair value at the acquisition date of the OVEC power purchase contract recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to this contract, which is being amortized over the same period as the intangible asset, eliminating any income statement impact. See Note 6 for additional information. Long-term intangible assets are presented as "Other intangibles" on the Balance Sheets. Amortization expense was as follows: 2017 2016 2015 Intangible assets with regulatory offset $ 6 $ 13 $ 24 Amortization expense for each of the next five years is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with regulatory offset $ 6 $ 6 $ 6 $ 6 $ 6 (KU) The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Coal contracts (a) $ — $ — $ 145 $ 145 Land and transmission rights 14 2 14 2 OVEC power purchase agreement (b) 39 18 39 15 Total subject to amortization $ 53 $ 20 $ 198 $ 162 (a) Gross carrying amount represents the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to these contracts, which was amortized over the same period as the intangible asset, eliminating any income statement impact. (b) Gross carrying amount represents the fair value at the acquisition date of the OVEC power purchase contract recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to this contract, which is being amortized over the same period as the intangible asset, eliminating any income statement impact. See Note 6 for additional information. Long-term intangible assets are presented as "Other intangibles" on the Balance Sheets. Amortization expense was as follows: 2017 2016 2015 Intangible assets with no regulatory offset $ — $ 1 $ — Intangible assets with regulatory offset 3 11 27 Total $ 3 $ 12 $ 27 Amortization expense for each of the next five years is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with regulatory offset $ 3 $ 3 $ 2 $ 2 $ 2

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	19. Asset Retirement Obligations (PPL) WPD has recorded conditional AROs required by U.K. law related to treated wood poles, gas-filled switchgear and fluid-filled cables. (PPL and PPL Electric) PPL Electric has identified legal retirement obligations for the retirement of certain transmission assets that could not be reasonably estimated due to indeterminable settlement dates. These assets are located on rights-of-way that allow the grantor to require PPL Electric to relocate or remove the assets. Since this option is at the discretion of the grantor of the right-of-way, PPL Electric is unable to determine when these events may occur. (PPL, LKE, LG&E and KU) LG&E's and KU's AROs are primarily related to the final retirement of assets associated with generating units. LG&E also has AROs related to natural gas mains and wells. LG&E's and KU's transmission and distribution lines largely operate under perpetual property easement agreements, which do not generally require restoration upon removal of the property. Therefore, no material AROs are recorded for transmission and distribution assets. As described in Notes 1 and 6, for LKE, LG&E and KU, all ARO accretion and depreciation expenses are reclassified as a regulatory asset. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, at the time of retirement, the related ARO regulatory asset is offset against the associated cost of removal regulatory liability, PP&E and ARO liability. The changes in the carrying amounts of AROs were as follows: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 ARO at beginning of period $ 488 $ 586 $ 433 $ 535 $ 145 $ 175 $ 288 $ 360 Accretion 21 24 20 22 7 7 13 15 Changes in estimated timing or cost (a) (73 ) (84 ) (54 ) (95 ) (8 ) (19 ) (46 ) (76 ) Effect of foreign currency exchange rates 4 (9 ) — — — — — — Obligations settled (43 ) (29 ) (43 ) (29 ) (23 ) (18 ) (20 ) (11 ) ARO at end of period $ 397 $ 488 $ 356 $ 433 $ 121 $ 145 $ 235 $ 288 (a) LKE recorded decreases of $60 million ( $52 million at KU and $8 million at LG&E) and $114 million ( $90 million at KU and $24 million at LG&E) to the existing AROs during 2017 and 2016 related to the closure of CCR impoundments. These revisions are the result of changes in closure plans related to expected costs and timing of closures. Further changes to AROs, capital plans or operating costs may be required as estimates of future cash flows are refined based on closure developments and regulatory or legal proceedings. See Note 13 for information on the final CCR rule and Note 6 for information on the rate recovery applications.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss)	20. Accumulated Other Comprehensive Income (Loss) (PPL and LKE) The after-tax changes in AOCI by component for the years ended December 31 were as follows: Unrealized gains (losses) Defined benefit plans Foreign currency translation adjustments Available- for-sale securities Qualifying derivatives Equity investees' AOCI Prior service costs Actuarial gain (loss) Total PPL December 31, 2014 $ (286 ) $ 201 $ 20 $ 1 $ 3 $ (2,213 ) $ (2,274 ) Amounts arising during the year (234 ) 8 26 — (9 ) (366 ) (575 ) Reclassifications from AOCI — (2 ) 2 (1 ) — 146 145 Net OCI during the year (234 ) 6 28 (1 ) (9 ) (220 ) (430 ) Distribution of PPL Energy — (207 ) (55 ) — — 238 (24 ) December 31, 2015 $ (520 ) $ — $ (7 ) $ — $ (6 ) $ (2,195 ) $ (2,728 ) Amounts arising during the year (1,107 ) — 91 — (3 ) (61 ) (1,080 ) Reclassifications from AOCI — — (91 ) (1 ) 1 121 30 Net OCI during the year (1,107 ) — — (1 ) (2 ) 60 (1,050 ) December 31, 2016 $ (1,627 ) $ — $ (7 ) $ (1 ) $ (8 ) $ (2,135 ) $ (3,778 ) Amounts arising during the year 538 — (79 ) — — (308 ) 151 Reclassifications from AOCI — — 73 1 1 130 205 Net OCI during the year 538 — (6 ) 1 1 (178 ) 356 December 31, 2017 $ (1,089 ) $ — $ (13 ) $ — $ (7 ) $ (2,313 ) $ (3,422 ) LKE December 31, 2014 $ — $ (8 ) $ (37 ) $ (45 ) Amounts arising during the year — (3 ) (4 ) (7 ) Reclassifications from AOCI — 1 5 6 Net OCI during the year — (2 ) 1 (1 ) December 31, 2015 $ — $ (10 ) $ (36 ) $ (46 ) Amounts arising during the year — — (27 ) (27 ) Reclassifications from AOCI (1 ) 2 2 3 Net OCI during the year (1 ) 2 (25 ) (24 ) December 31, 2016 $ (1 ) $ (8 ) $ (61 ) $ (70 ) Amounts arising during the year — (2 ) (23 ) (25 ) Reclassifications from AOCI 1 1 5 7 Net OCI during the year 1 (1 ) (18 ) (18 ) December 31, 2017 $ — $ (9 ) $ (79 ) $ (88 ) The following table presents PPL's gains (losses) and related income taxes for reclassifications from AOCI for the years ended December 31, 2017 , 2016 and 2015 . LKE amounts are insignificant for the years ended December 31, 2017 , 2016 and 2015 . The defined benefit plan components of AOCI are not reflected in their entirety in the statement of income; rather, they are included in the computation of net periodic defined benefit costs (credits) and subject to capitalization. See Note 11 for additional information. PPL Details about AOCI 2017 2016 2015 Affected Line Item on the Available-for-sale securities $ — $ — $ 4 Other Income (Expense) - net Total Pre-tax — — 4 Income Taxes — — (2 ) Total After-tax — — 2 PPL Details about AOCI 2017 2016 2015 Affected Line Item on the Qualifying derivatives Interest rate swaps (9 ) (7 ) (11 ) Interest Expense — — (77 ) Discontinued operations Cross-currency swaps (82 ) 116 49 Other Income (Expense) - net — 3 2 Interest Expense Commodity contracts — — 20 Discontinued operations Total Pre-tax (91 ) 112 (17 ) Income Taxes 18 (21 ) 15 Total After-tax (73 ) 91 (2 ) Equity Investees' AOCI (1 ) 1 1 Other Income (Expense) - net Total Pre-tax (1 ) 1 1 Income Taxes — — — Total After-tax (1 ) 1 1 Defined benefit plans Prior service costs (2 ) (2 ) — Net actuarial loss (167 ) (156 ) (192 ) Total Pre-tax (169 ) (158 ) (192 ) Income Taxes 38 36 46 Total After-tax (131 ) (122 ) (146 ) Total reclassifications during the year $ (205 ) $ (30 ) $ (145 )
LG And E And KU Energy LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss)	20. Accumulated Other Comprehensive Income (Loss) (PPL and LKE) The after-tax changes in AOCI by component for the years ended December 31 were as follows: Unrealized gains (losses) Defined benefit plans Foreign currency translation adjustments Available- for-sale securities Qualifying derivatives Equity investees' AOCI Prior service costs Actuarial gain (loss) Total PPL December 31, 2014 $ (286 ) $ 201 $ 20 $ 1 $ 3 $ (2,213 ) $ (2,274 ) Amounts arising during the year (234 ) 8 26 — (9 ) (366 ) (575 ) Reclassifications from AOCI — (2 ) 2 (1 ) — 146 145 Net OCI during the year (234 ) 6 28 (1 ) (9 ) (220 ) (430 ) Distribution of PPL Energy — (207 ) (55 ) — — 238 (24 ) December 31, 2015 $ (520 ) $ — $ (7 ) $ — $ (6 ) $ (2,195 ) $ (2,728 ) Amounts arising during the year (1,107 ) — 91 — (3 ) (61 ) (1,080 ) Reclassifications from AOCI — — (91 ) (1 ) 1 121 30 Net OCI during the year (1,107 ) — — (1 ) (2 ) 60 (1,050 ) December 31, 2016 $ (1,627 ) $ — $ (7 ) $ (1 ) $ (8 ) $ (2,135 ) $ (3,778 ) Amounts arising during the year 538 — (79 ) — — (308 ) 151 Reclassifications from AOCI — — 73 1 1 130 205 Net OCI during the year 538 — (6 ) 1 1 (178 ) 356 December 31, 2017 $ (1,089 ) $ — $ (13 ) $ — $ (7 ) $ (2,313 ) $ (3,422 ) LKE December 31, 2014 $ — $ (8 ) $ (37 ) $ (45 ) Amounts arising during the year — (3 ) (4 ) (7 ) Reclassifications from AOCI — 1 5 6 Net OCI during the year — (2 ) 1 (1 ) December 31, 2015 $ — $ (10 ) $ (36 ) $ (46 ) Amounts arising during the year — — (27 ) (27 ) Reclassifications from AOCI (1 ) 2 2 3 Net OCI during the year (1 ) 2 (25 ) (24 ) December 31, 2016 $ (1 ) $ (8 ) $ (61 ) $ (70 ) Amounts arising during the year — (2 ) (23 ) (25 ) Reclassifications from AOCI 1 1 5 7 Net OCI during the year 1 (1 ) (18 ) (18 ) December 31, 2017 $ — $ (9 ) $ (79 ) $ (88 ) The following table presents PPL's gains (losses) and related income taxes for reclassifications from AOCI for the years ended December 31, 2017 , 2016 and 2015 . LKE amounts are insignificant for the years ended December 31, 2017 , 2016 and 2015 . The defined benefit plan components of AOCI are not reflected in their entirety in the statement of income; rather, they are included in the computation of net periodic defined benefit costs (credits) and subject to capitalization. See Note 11 for additional information. PPL Details about AOCI 2017 2016 2015 Affected Line Item on the Available-for-sale securities $ — $ — $ 4 Other Income (Expense) - net Total Pre-tax — — 4 Income Taxes — — (2 ) Total After-tax — — 2 PPL Details about AOCI 2017 2016 2015 Affected Line Item on the Qualifying derivatives Interest rate swaps (9 ) (7 ) (11 ) Interest Expense — — (77 ) Discontinued operations Cross-currency swaps (82 ) 116 49 Other Income (Expense) - net — 3 2 Interest Expense Commodity contracts — — 20 Discontinued operations Total Pre-tax (91 ) 112 (17 ) Income Taxes 18 (21 ) 15 Total After-tax (73 ) 91 (2 ) Equity Investees' AOCI (1 ) 1 1 Other Income (Expense) - net Total Pre-tax (1 ) 1 1 Income Taxes — — — Total After-tax (1 ) 1 1 Defined benefit plans Prior service costs (2 ) (2 ) — Net actuarial loss (167 ) (156 ) (192 ) Total Pre-tax (169 ) (158 ) (192 ) Income Taxes 38 36 46 Total After-tax (131 ) (122 ) (146 ) Total reclassifications during the year $ (205 ) $ (30 ) $ (145 )

New Accounting Guidance Pending

New Accounting Guidance Pending Adoption	12 Months Ended
	Dec. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Guidance Pending Adoption	21. New Accounting Guidance Pending Adoption (All Registrants) Accounting for Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (FASB) issued accounting guidance that establishes a comprehensive new model for the recognition of revenue from contracts with customers. This model is based on the core principle that revenue should be recognized 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 Registrants have completed an assessment of their revenue under this new guidance and have determined it will not have a material impact on their current revenue recognition policies. The Registrants' operating revenues are derived primarily from tariff-based sales that result from providing electricity and natural gas to customers with no defined contractual term. Tariff-based sales are within the scope of the new guidance, and operating revenues under the new guidance will be equivalent to the electricity and natural gas delivered and billed in that period (including estimated billings), which is consistent with current practice. The disclosure requirements included in the standard will result in increased information being provided to enable the users of the financial statements to understand the nature, amount, timing and uncertainty of revenue arising from contracts with customers. The Registrants will include disaggregation of revenues by geographic location, customer class or type of service, as applicable. Some revenue arrangements, including alternative revenue programs and lease income, are excluded from the scope of the new guidance and will be accounted for and disclosed separately from revenues from contracts with customers. The Registrants will also disclose the opening and closing balances of accounts receivable and any contract assets or contract liabilities resulting from contracts with customers. The Registrants adopted this guidance effective January 1, 2018 using the modified retrospective transition method. Accounting for Leases In February 2016, the FASB issued accounting guidance for leases. This new guidance requires lessees to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). For income statement purposes, the FASB retained a dual model for lessees, requiring leases to be classified as either operating or finance. Operating leases will result in straight-line expense (similar to current operating leases) while finance leases will result in a front-loaded expense pattern (similar to current capital leases). Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright line tests. Lessor accounting under the new guidance is similar to the current model, but updated to align with certain changes to the lessee model and the new revenue recognition standard. Similar to current practice, lessors will classify leases as operating, direct financing, or sales-type. The standard is effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition, and provides for certain practical expedients. One of these practical expedients allows entities to elect to not evaluate land easements as leases that exist or expired before the adoption date and were not previously accounted for as leases under current lease guidance. Transition will require application of the new guidance at the beginning of the earliest comparative period presented. The Registrants are currently assessing the impact of adopting this guidance. The Registrants will adopt this guidance effective January 1, 2019. Accounting for Financial Instrument Credit Losses In June 2016, the FASB issued accounting guidance that requires the use of a current expected credit loss (CECL) model for the measurement of credit losses on financial instruments within the scope of this guidance, which includes accounts receivable. The CECL model requires an entity to measure credit losses using historical information, current information and reasonable and supportable forecasts of future events, rather than the incurred loss impairment model required under current GAAP. For public business entities, this guidance will be applied using a modified retrospective approach and is effective for fiscal years beginning after December 15, 2019, and interim periods within those years. All entities may early adopt this guidance beginning after December 15, 2018, including interim periods within those years. The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it. Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost In March 2017, the FASB issued accounting guidance that changes the income statement presentation of net periodic benefit cost. This new guidance requires the service cost component to be disaggregated from other components of net benefit cost and presented in the same income statement line items as other employee compensation costs arising from services rendered during the period. The other components of net periodic benefits will be presented separately from the line items that include the service cost and outside of any subtotal of operating income. Only the service cost component is eligible for capitalization. For public business entities, the guidance on the presentation of the components of net periodic benefit costs will be applied retrospectively. The guidance that limits the capitalization to the service cost component of net periodic benefit costs will be applied prospectively. This guidance is effective for fiscal years beginning after December 15, 2017 and interim periods within those years. The Registrants adopted this guidance effective January 1, 2018. For PPL’s, LKE’s and LG&E’s U.S. defined benefit pension and PPL's and LKE's other postretirement benefit plans, the adoption of this new guidance is not expected to have a material impact on either the presentation on the income statements or the amounts capitalized and related impact to expense, as the difference between the service cost and the non-service cost components of net periodic benefit costs has not historically been and is not expected to be material in 2018. For PPL’s U.K. defined benefit pension plans, the non-service cost components of net periodic benefit cost has been in a net-credit position for the current reporting periods and is expected to continue to be in a net-credit position for 2018. Therefore, the estimated impact of adopting this new guidance related to the non-service cost component credits to be reclassified from “Other operation and maintenance” to “Other Income (Expense)-net” on the Statements of Income is approximately $175 million and $120 million for the years ended 2017 and 2016. The Registrants are finalizing the expected 2018 impacts of adopting the guidance as the amounts are affected by market conditions and assumptions selected at December 31, 2017. Improvements to Accounting for Hedging Activities In August 2017, the FASB issued accounting guidance that reduces complexity when applying hedge accounting as well as improves transparency about an entity's risk management activities. This guidance eliminates recognizing hedge ineffectiveness for cash flow and net investment hedges and provides for the ability to perform subsequent effectiveness assessments qualitatively. The guidance also makes certain changes to allowable methodologies such as allowing entities to apply the short-cut method to partial-term fair value hedges of interest rate risk as well as expands the ability to apply the critical terms match method to cash flow hedges of groups of forecasted transactions. The guidance also updates certain recognition and presentation requirements as well as disclosure requirements. For public business entities, this guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. This standard must be adopted using a modified retrospective approach and provides for certain transition elections that must be made prior to the first effectiveness testing date after adoption. The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it. (PPL, LKE, LG&E and KU) Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued accounting guidance that simplifies the test for goodwill impairment by eliminating the second step of the quantitative test. The second step of the quantitative test requires a calculation of the implied fair value of goodwill, which is determined in the same manner as the amount of goodwill in a business combination. Under this new guidance, an entity will now compare the estimated fair value of a reporting unit with its carrying value and recognize an impairment charge for the amount the carrying amount exceeds the fair value of the reporting unit. For public business entities, this guidance will be applied prospectively and is effective for annual or any interim goodwill impairment tests for fiscal years beginning after December 15, 2019. All entities may early adopt this guidance for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it. (PPL and LKE) Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, the FASB issued accounting guidance that gives entities the option to reclassify tax effects stranded within AOCI as a result of the TCJA to retained earnings. The reclassification applies only to those stranded tax effects arising from the TCJA enactment. Certain disclosures related to the stranded tax effects, including a description of the accounting policy for releasing income tax effects from AOCI, are required. For all entities, this guidance is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. Early adoption is permitted, including adoption in any interim period. The amendments should be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the TCJA is recognized. The Registrants are currently assessing this guidance and the period in which they will adopt it.

SCHEDULE I - CONDENSED UNCONSOL

SCHEDULE I - CONDENSED UNCONSOLICATED FINANCIAL STATEMENTS AND NOTES TO CONDENSED UNCONSOLIDATED FINANCIAL STATEMENTS	12 Months Ended
	Dec. 31, 2017
PPL Corp [Member]
Condensed Unconsolidated Financial Information [Line Items]
Schedule I - Condensed Unconsolidated Financial Information	SCHEDULE I - PPL CORPORATION CONDENSED UNCONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME FOR THE YEARS ENDED DECEMBER 31, (Millions of Dollars, except share data) 2017 2016 2015 Operating Revenues $ — $ — $ — Operating Expenses Other operation and maintenance 2 2 9 Total Operating Expenses 2 2 9 Operating Loss (2 ) (2 ) (9 ) Other Income (Expense) - net Equity in earnings of subsidiaries 1,175 1,915 711 Other income (expense) (1 ) (1 ) (15 ) Total 1,174 1,914 696 Interest Expense 8 8 9 Interest Expense with Affiliates 16 10 10 Income Before Income Taxes 1,148 1,894 668 Income Taxes 20 (8 ) (14 ) Net Income $ 1,128 $ 1,902 $ 682 Total other comprehensive income (loss) 356 (1,050 ) (430 ) Comprehensive Income Attributable to PPL Shareowners $ 1,484 $ 852 $ 252 Earnings Per Share of Common Stock: Net Income Available to PPL Common Shareowners: Basic $ 1.64 $ 2.80 $ 1.01 Diluted $ 1.64 $ 2.79 $ 1.01 Weighted-Average Shares of Common Stock Outstanding (in thousands) Basic 685,240 677,592 669,814 Diluted 687,334 680,446 672,586 The accompanying Notes to Condensed Unconsolidated Financial Statements are an integral part of the financial statements. SCHEDULE I - PPL CORPORATION CONDENSED UNCONSOLIDATED STATEMENTS OF CASH FLOWS FOR THE YEARS ENDED DECEMBER 31, (Millions of Dollars) 2017 2016 2015 Cash Flows from Operating Activities Net cash provided by (used in) operating activities $ 1,108 $ 1,563 $ 993 Cash Flows from Investing Activities Capital contributions to affiliated subsidiaries (585 ) (308 ) (491 ) Return of capital from affiliated subsidiaries — — 112 Net cash provided by (used in) investing activities (585 ) (308 ) (379 ) Cash Flows from Financing Activities Issuance of equity, net of issuance costs 453 144 203 Net increase (decrease) in short-term debt with affiliates 113 (341 ) 215 Payment of common stock dividends (1,072 ) (1,030 ) (1,004 ) Other (21 ) (24 ) (28 ) Net cash provided by (used in) financing activities (527 ) (1,251 ) (614 ) Net Increase (Decrease) in Cash and Cash Equivalents Cash and Cash Equivalents at Beginning of Period 4 — — Cash and Cash Equivalents at End of Period $ — $ 4 $ — Supplemental Disclosures of Cash Flow Information: Cash Dividends Received from Subsidiaries $ 1,253 $ 1,510 $ 1,198 The accompanying Notes to Condensed Unconsolidated Financial Statements are an integral part of the financial statements. SCHEDULE I - PPL CORPORATION CONDENSED UNCONSOLIDATED BALANCE SHEETS AT DECEMBER 31, (Millions of Dollars, shares in thousands) 2017 2016 Assets Current Assets Cash and cash equivalents $ — $ 4 Accounts Receivable Other 7 7 Affiliates 17 10 Price risk management assets 196 63 Total Current Assets 220 84 Investments Affiliated companies at equity 11,141 10,160 Other Noncurrent Assets Deferred income taxes 46 70 Price risk management assets 186 284 Other noncurrent assets 1 1 Total Other Noncurrent Assets 233 355 Total Assets $ 11,594 $ 10,599 Liabilities and Equity Current Liabilities Short-term debt with affiliates $ 157 $ 44 Accounts payable with affiliates 2 30 Dividends 273 259 Price risk management liabilities 233 237 Other current liabilities 19 20 Total Current Liabilities 684 590 Deferred Credits and Other Noncurrent Liabilities 149 110 Equity Common stock - $0.01 par value (a) 7 7 Additional paid-in capital 10,305 9,841 Earnings reinvested 3,871 3,829 Accumulated other comprehensive loss (3,422 ) (3,778 ) Total Equity 10,761 9,899 Total Liabilities and Equity $ 11,594 $ 10,599 (a) 1,560,000 shares authorized; 693,398 and 679,731 shares issued and outstanding at December 31, 2017 and December 31, 2016. The accompanying Notes to Condensed Unconsolidated Financial Statements are an integral part of the financial statements. SCHEDULE I - PPL CORPORATION NOTES TO CONDENSED UNCONSOLIDATED FINANCIAL STATEMENTS 1. Basis of Presentation PPL Corporation is a holding company and conducts substantially all of its business operations through its subsidiaries. Substantially all of its consolidated assets are held by such subsidiaries. PPL Corporation uses the equity method to account for its investments in entities in which it has a controlling financial interest. PPL Corporation's cash flow and its ability to meet its obligations are largely dependent upon the earnings of these subsidiaries and the distribution or other payment of such earnings to it in the form of dividends, loans or advances or repayment of loans and advances from it. These condensed financial statements and related footnotes have been prepared in accordance with Reg. §210.12-04 of Regulation S-X. These statements should be read in conjunction with the consolidated financial statements and notes thereto of PPL Corporation. PPL Corporation indirectly or directly owns all of the ownership interests of its significant subsidiaries. PPL Corporation relies on dividends or loans from its subsidiaries to fund PPL Corporation's dividends to its common shareowners and to meet its other cash requirements. See Note 7 to PPL Corporation's consolidated financial statements for discussions related to restricted net assets of its subsidiaries for the purposes of transferring funds to PPL in the form of distributions, loans or advances. 2. Commitments and Contingencies See Note 13 to PPL Corporation's consolidated financial statements for commitments and contingencies of its subsidiaries. Guarantees and Other Assurances PPL Corporation's subsidiaries are separate and distinct legal entities and have no obligation to pay any amounts that may become due under PPL Corporation's guarantees or other assurances or to make any funds available for such payment. PPL Corporation fully and unconditionally guarantees the payment of principal, premium and interest on all of the debt securities of PPL Capital Funding. The estimated maximum potential amount of future payments that could be required under the guarantees at December 31, 2017 was $9.7 billion . These guarantees will expire in 2073 . The probability of expected payment under these guarantees is remote.
L G And E And K U Energy L L C Unconsolidated [Member]
Condensed Unconsolidated Financial Information [Line Items]
Schedule I - Condensed Unconsolidated Financial Information	SCHEDULE I - LG&E and KU Energy LLC CONDENSED UNCONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME FOR THE YEARS ENDED DECEMBER 31, (Millions of Dollars) 2017 2016 2015 Other Income (Expense) - net Equity in Earnings of Subsidiaries $ 397 $ 452 $ 390 Interest Income with Affiliate 14 9 4 Total 411 461 394 Interest Expense 30 29 39 Interest Expense with Affiliate 20 18 5 Income Before Income Taxes 361 414 350 Income Tax Expense (Benefit) 45 (15 ) (14 ) Net Income $ 316 $ 429 $ 364 Total other comprehensive loss (18 ) (24 ) (1 ) Comprehensive Income Attributable to Member $ 298 $ 405 $ 363 The accompanying Notes to Condensed Unconsolidated Financial Statements are an integral part of the financial statements. SCHEDULE I - LG&E and KU Energy LLC CONDENSED UNCONSOLIDATED STATEMENTS OF CASH FLOWS FOR THE YEARS ENDED DECEMBER 31, (Millions of Dollars) 2017 2016 2015 Cash Flows from Operating Activities Net cash provided by (used in) operating activities $ 401 $ 285 $ 246 Cash Flows from Investing Activities Capital contributions to affiliated subsidiaries (30 ) (91 ) (140 ) Net decrease (increase) in notes receivable from affiliates (28 ) 47 73 Net cash provided by (used in) investing activities (58 ) (44 ) (67 ) Cash Flows from Financing Activities Net increase (decrease) in notes payable with affiliates 58 90 315 Net increase (decrease) in short-term debt — (75 ) — Retirement of long-term debt — — (400 ) Contribution from member — 61 125 Distribution to member (402 ) (316 ) (219 ) Net cash provided by (used in) financing activities (344 ) (240 ) (179 ) Net Increase (Decrease) in Cash and Cash Equivalents (1 ) 1 — Cash and Cash Equivalents at Beginning of Period 1 — — Cash and Cash Equivalents at End of Period $ — $ 1 $ — Supplemental disclosures of cash flow information: Cash Dividends Received from Subsidiaries $ 418 $ 376 $ 272 The accompanying Notes to Condensed Unconsolidated Financial Statements are an integral part of the financial statements. SCHEDULE I - LG&E and KU Energy LLC CONDENSED UNCONSOLIDATED BALANCE SHEETS AT DECEMBER 31, (Millions of Dollars) 2017 2016 Assets Current Assets Cash and cash equivalents $ — $ 1 Accounts receivable 1 — Accounts receivable from affiliates 8 23 Income taxes receivable 1 31 Notes receivable from affiliates 1,035 1,007 Total Current Assets 1,045 1,062 Investments Affiliated companies at equity 5,209 5,219 Other Noncurrent Assets Deferred income taxes 263 227 Total Assets $ 6,517 $ 6,508 Liabilities and Equity Current Liabilities Notes payable to affiliates $ 241 $ 179 Accounts payable to affiliates 469 450 Taxes 35 — Other current liabilities 5 6 Total Current Liabilities 750 635 Long-term Debt Long-term debt 722 721 Notes payable to affiliates 476 480 Total Long-term Debt 1,198 1,201 Deferred Credits and Other Noncurrent Liabilities 6 5 Equity 4,563 4,667 Total Liabilities and Equity $ 6,517 $ 6,508 The accompanying Notes to Condensed Unconsolidated Financial Statements are an integral part of the financial statements. Schedule I - LG&E and KU Energy LLC Notes to Condensed Unconsolidated Financial Statements 1. Basis of Presentation LG&E and KU Energy LLC (LKE) is a holding company and conducts substantially all of its business operations through its subsidiaries. Substantially all of its consolidated assets are held by such subsidiaries. LKE uses the equity method to account for its investments in entities in which it has a controlling financial interest. LKE's cash flow and its ability to meet its obligations are largely dependent upon the earnings of these subsidiaries and the distribution or other payment of such earnings to it in the form of dividends or repayment of loans and advances from the subsidiaries. These condensed financial statements and related footnotes have been prepared in accordance with Reg. §210.12-04 of Regulation S-X. These statements should be read in conjunction with the consolidated financial statements and notes thereto of LKE. LKE indirectly or directly owns all of the ownership interests of its significant subsidiaries. LKE relies primarily on dividends from its subsidiaries to fund LKE's distributions to its member and to meet its other cash requirements. See Note 7 to LKE's consolidated financial statements for discussions related to restricted net assets of its subsidiaries for the purposes of transferring funds to LKE in the form of distributions, loans or advances. 2. Commitments and Contingencies See Note 13 to LKE's consolidated financial statements for commitments and contingencies of its subsidiaries. Guarantees LKE provides certain indemnifications covering the due and punctual payment, performance and discharge by each party of its respective obligations. The most comprehensive of these guarantees is the LKE guarantee covering operational, regulatory and environmental commitments and indemnifications made by WKE under a 2009 Transaction Termination Agreement. This guarantee has a term of 12 years ending July 2021 , and a maximum exposure of $200 million , exclusive of certain items such as government fines and penalties that may exceed the maximum. Another WKE-related LKE guarantee formerly covered other indemnifications related to the purchase price of excess power, had a term expiring in 2023 , and a maximum exposure of $100 million , which excess power matter and related indemnifications had been the subject of a dispute and legal proceeding among the parties. In December 2017, the parties executed settlement agreements which resolved all claims relating to the excess power matter, and terminated such guarantee, for $11 million . Additionally, LKE has indemnified various third parties related to historical obligations for other divested subsidiaries and affiliates. The indemnifications vary by entity and the maximum exposures range from being capped at the sale price to no specified maximum. LKE could be required to perform on these indemnifications in the event of covered losses or liabilities being claimed by an indemnified party. LKE cannot predict the ultimate outcomes of the various indemnification scenarios, but does not expect such outcomes to result in significant losses above the amounts recorded. 3. Long-Term Debt See Note 7 to LKE's consolidated financial statements for the terms of LKE's outstanding senior unsecured notes outstanding. Of the total outstanding, $475 million matures in 2020 and $250 million matures in 2021 . These maturities are based on stated maturities. Also see Note 7 to LKE's consolidated financial statements for the terms of LKE's $400 million note payable to a PPL affiliate. This note matures in 2026 . LKE's $76 million note payable to LG&E and KU Services Company bears a variable interest rate, which resets each quarter based on LIBOR. The rate at December 31, 2017 was 2.1% . This note matures in 2019 .

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Unaudited [Line Items]
Quarterly Financial Information (Unaudited)	QUARTERLY FINANCIAL, COMMON STOCK PRICE AND DIVIDEND DATA (Unaudited) PPL Corporation and Subsidiaries (Millions of Dollars, except per share data) For the Quarters Ended (a) March 31 June 30 Sept. 30 Dec. 31 2017 Operating revenues $ 1,951 $ 1,725 $ 1,845 $ 1,926 Operating income 796 702 777 793 Net income 403 292 355 78 Net income available to PPL common shareowners: (b) Basic EPS 0.59 0.43 0.52 0.11 Diluted EPS 0.59 0.43 0.51 0.11 Dividends declared per share of common stock (c) 0.3950 0.3950 0.3950 0.3950 Price per common share: High $ 37.70 $ 40.06 $ 39.83 $ 38.37 Low 33.94 37.11 37.36 30.76 2016 Operating revenues $ 2,011 $ 1,785 $ 1,889 $ 1,832 Operating income 823 725 786 714 Net income 481 483 473 465 Net income available to PPL common shareowners: (b) Basic EPS 0.71 0.71 0.70 0.68 Diluted EPS 0.71 0.71 0.69 0.68 Dividends declared per share of common stock (c) 0.38 0.38 0.38 0.38 Price per common share: High $ 38.07 $ 39.68 $ 37.71 $ 34.74 Low 32.80 36.27 33.63 32.19 (a) Quarterly results can vary depending on, among other things, weather. Accordingly, comparisons among quarters of a year may not be indicative of overall trends and changes in operations. (b) The sum of the quarterly amounts may not equal annual earnings per share due to changes in the number of common shares outstanding during the year or rounding. (c) PPL has paid quarterly cash dividends on its common stock in every year since 1946. Future dividends, declared at the discretion of the Board of Directors, will be dependent upon future earnings, cash flows, financial requirements and other factors.
PPL Electric Utilities Corp [Member]
Quarterly Financial Information Unaudited [Line Items]
Quarterly Financial Information (Unaudited)	QUARTERLY FINANCIAL DATA (Unaudited) PPL Electric Utilities Corporation and Subsidiaries (Millions of Dollars) For the Quarters Ended (a) March 31 June 30 Sept. 30 Dec. 31 2017 Operating revenues $ 573 $ 500 $ 547 $ 575 Operating income 159 156 189 197 Net income 79 77 95 111 2016 Operating revenues $ 585 $ 495 $ 539 $ 537 Operating income 180 154 176 154 Net income 94 79 90 77 (a) PPL Electric's business is seasonal in nature, with peak sales periods generally occurring in the winter and summer months. Accordingly, comparisons among quarters of a year may not be indicative of overall trends and changes in operations.

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Summary of Significant Accounting Policies [Line Items]
Business and Consolidation	Business and Consolidation (PPL) PPL is a utility holding company that, through its regulated subsidiaries, is primarily engaged in: 1) the distribution of electricity in the U.K.; 2) the generation, transmission, distribution and sale of electricity and the distribution and sale of natural gas, primarily in Kentucky; and 3) the transmission, distribution and sale of electricity in Pennsylvania. Headquartered in Allentown, PA, PPL's principal subsidiaries are PPL Global, LKE (including its principal subsidiaries, LG&E and KU) and PPL Electric. PPL's corporate level financing subsidiary is PPL Capital Funding. WPD, a subsidiary of PPL Global, through indirect, wholly owned subsidiaries, operates distribution networks providing electricity service in the U.K. WPD serves end-users in South Wales and southwest and central England. Its principal subsidiaries are WPD (South Wales), WPD (South West), WPD (East Midlands) and WPD (West Midlands). PPL consolidates WPD on a one -month lag. Material events, such as debt issuances that occur in the lag period, are recognized in the current period financial statements. Events that are significant but not material are disclosed. (PPL and PPL Electric) PPL Electric is a cost-based rate-regulated utility subsidiary of PPL. PPL Electric's principal business is the transmission and distribution of electricity to serve retail customers in its franchised territory in eastern and central Pennsylvania and the regulated supply of electricity to retail customers in that territory as a PLR. (PPL, LKE, LG&E and KU) LKE is a utility holding company with cost-based rate-regulated utility operations through its subsidiaries, LG&E and KU. LG&E and KU are engaged in the generation, transmission, distribution and sale of electricity. LG&E also engages in the distribution and sale of natural gas. LG&E and KU maintain their separate identities and serve customers in Kentucky under their respective names. KU also serves customers in Virginia under the Old Dominion Power name and in Tennessee under the KU name. (PPL) "Loss from Discontinued Operations (net of income taxes)" on the 2015 Statement of Income includes the activities of PPL Energy Supply, substantially representing PPL's former Supply segment, which was spun off and distributed to PPL shareowners on June 1, 2015. In addition, the Statement of Cash Flows for the same period separately reports the cash flows of the discontinued operations. See Note 8 for additional information. (All Registrants) The financial statements of the Registrants include each company's own accounts as well as the accounts of all entities in which the company has a controlling financial interest. Entities for which a controlling financial interest is not demonstrated through voting interests are evaluated based on accounting guidance for Variable Interest Entities (VIEs). The Registrants consolidate a VIE when they are determined to have a controlling interest in the VIE, and as a result are the primary beneficiary of the entity. The Registrants are not the primary beneficiary in any VIEs. Investments in entities in which a company has the ability to exercise significant influence but does not have a controlling financial interest are accounted for under the equity method. All other investments are carried at cost or fair value. All significant intercompany transactions have been eliminated. The financial statements of PPL, LKE, LG&E and KU include their share of any undivided interests in jointly owned facilities, as well as their share of the related operating costs of those facilities. See Note 12 for additional information.
Regulation	Regulation (PPL) WPD operates in an incentive-based regulatory structure under distribution licenses granted by Ofgem. Electricity distribution revenues are set by Ofgem for a given time period through price control reviews that are not directly based on cost recovery. The price control formula that governs WPD's allowed revenue is designed to provide economic incentives to minimize operating, capital and financing costs. As a result, WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP and does not record regulatory assets and liabilities. (PPL Electric, LG&E and KU) PPL Electric, LG&E and KU are cost-based rate-regulated utilities for which rates are set by regulators to enable PPL Electric, LG&E and KU to recover the costs of providing electric or gas service, as applicable, and to provide a reasonable return to shareholders. Base rates are generally established based on a future test period. As a result, the financial statements are subject to the accounting for certain types of regulation as prescribed by GAAP and reflect the effects of regulatory actions. Regulatory assets are recognized for the effect of transactions or events where future recovery of underlying costs is probable in regulated customer rates. The effect of such accounting is to defer certain or qualifying costs that would otherwise currently be charged to expense. Regulatory liabilities are recognized for amounts expected to be returned through future regulated customer rates. In certain cases, regulatory liabilities are recorded based on an understanding or agreement with the regulator that rates have been set to recover costs that are expected to be incurred in the future, and the regulated entity is accountable for any amounts charged pursuant to such rates and not yet expended for the intended purpose. The accounting for regulatory assets and regulatory liabilities is based on specific ratemaking decisions or precedent for each transaction or event as prescribed by the FERC or the applicable state regulatory commissions. See Note 6 for additional details regarding regulatory matters.
Accounting Records	Accounting Records The system of accounts for domestic regulated entities is maintained in accordance with the Uniform System of Accounts prescribed by the FERC and adopted by the applicable state regulatory commissions.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Loss Accruals	Loss Accruals Potential losses are accrued when (1) information is available that indicates it is "probable" that a loss has been incurred, given the likelihood of the uncertain future events and (2) the amount of the loss can be reasonably estimated. Accounting guidance defines "probable" as cases in which "the future event or events are likely to occur." The Registrants continuously assess potential loss contingencies for environmental remediation, litigation claims, regulatory penalties and other events. Loss accruals for environmental remediation are discounted when appropriate. The accrual of contingencies that might result in gains is not recorded, unless realization is assured.
Earnings Per Share	Earnings Per Share (PPL) EPS is computed using the two-class method, which is an earnings allocation method for computing EPS that treats a participating security as having rights to earnings that would otherwise have been available to common shareowners. Share-based payment awards that provide recipients a non-forfeitable right to dividends or dividend equivalents are considered participating securities.
Price Risk Management	Price Risk Management (All Registrants) Interest rate contracts are used to hedge exposure to changes in the fair value of debt instruments and to hedge exposure to variability in expected cash flows associated with existing floating-rate debt instruments or forecasted fixed-rate issuances of debt. Foreign currency exchange contracts are used to hedge foreign currency exposures, primarily associated with PPL's investments in U.K. subsidiaries. Similar derivatives may receive different accounting treatment, depending on management's intended use and documentation. Certain contracts may not meet the definition of a derivative because they lack a notional amount or a net settlement provision. In cases where there is no net settlement provision, markets are periodically assessed to determine whether market mechanisms have evolved that would facilitate net settlement. Certain derivative contracts may be excluded from the requirements of derivative accounting treatment because NPNS has been elected. These contracts are accounted for using accrual accounting. Contracts that have been classified as derivative contracts are reflected on the balance sheets at fair value. The portion of derivative positions that deliver within a year are included in "Current Assets" and "Current Liabilities," while the portion of derivative positions that deliver beyond a year are recorded in "Other Noncurrent Assets" and "Deferred Credits and Other Noncurrent Liabilities." Cash inflows and outflows related to derivative instruments are included as a component of operating, investing or financing activities on the Statements of Cash Flows, depending on the classification of the hedged items. PPL and its subsidiaries have elected not to offset net derivative positions against the right to reclaim cash collateral (a receivable) or the obligation to return cash collateral (a payable) under master netting arrangements. (PPL) Processes exist that allow for subsequent review and validation of the contract information as it relates to interest rate and foreign currency derivatives. The accounting department provides the treasury department with guidelines on appropriate accounting classifications for various contract types and strategies. Examples of accounting guidelines provided to the treasury department staff include, but are not limited to: • Transactions to lock in an interest rate prior to a debt issuance can be designated as cash flow hedges, to the extent the forecasted debt issuances remain probable of occurring. • Cross-currency transactions to hedge interest and principal repayments can be designated as cash flow hedges. • Transactions to hedge fluctuations in the fair value of existing debt can be designated as fair value hedges. • Transactions to hedge the value of a net investment of foreign operations can be designated as net investment hedges. • Derivative transactions that do not qualify for cash flow or net investment hedge treatment are marked to fair value through earnings. These transactions generally include foreign currency forwards and options to hedge GBP-denominated earnings translation risk associated with PPL's U.K. subsidiaries that report their financial statements in GBP. As such, these transactions reduce earnings volatility due solely to changes in foreign currency exchange rates. (All Registrants) • Derivative transactions may be marked to fair value through regulatory assets/liabilities at PPL Electric, LG&E and KU if approved by the appropriate regulatory body. These transactions generally include the effect of interest rate swaps that are included in customer rates. (PPL and PPL Electric) To meet its obligation as a PLR to its customers, PPL Electric has entered into certain contracts that meet the definition of a derivative. However, NPNS has been elected for these contracts. See Notes 16 and 17 for additional information on derivatives. All derivative instruments are recorded at fair value on the Balance Sheet as an asset or liability unless NPNS is elected. NPNS contracts for PPL and PPL Electric include certain full-requirement purchase contracts and other physical purchase contracts. Changes in the fair value of derivatives not designated as NPNS are recognized in earnings unless specific hedge accounting criteria are met and designated as such, except for the changes in fair values of LG&E's interest rate swaps that are recognized as regulatory assets or regulatory liabilities.
Revenue Recognition	Revenue Recognition (All Registrants) Operating revenues are primarily recorded based on energy deliveries through the end of the calendar month. Unbilled retail revenues result because customers' bills are rendered throughout the month, rather than bills being rendered at the end of the month. For LKE, LG&E and KU, unbilled revenues for a month are calculated by multiplying an estimate of unbilled kWh by the estimated average cents per kWh. Any difference between estimated and actual revenues is adjusted the following month when the previous unbilled estimate is reversed and actual billings occur. For PPL Electric, unbilled revenues for a month are calculated by multiplying the actual unbilled kWh by an average rate per customer class. (PPL) WPD is currently operating under the eight-year price control period of RIIO-ED1, which commenced for electric distribution companies on April 1, 2015. Ofgem has adopted a price control mechanism that establishes the amount of base demand revenue WPD can earn, subject to certain true-ups, and provides for an increase or reduction in revenues based on incentives or penalties for performance relative to pre-established targets. WPD's allowed revenue primarily includes base demand revenue (adjusted for inflation using RPI), performance incentive revenues/penalties and adjustments for over or under-recovery from prior periods. As the regulatory model is incentive based rather than a cost recovery model, WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. Therefore, the accounting treatment of adjustments to base demand revenue and/or allowed revenue is evaluated primarily based on revenue recognition accounting guidance. Unlike prior price control reviews, base demand revenue under RIIO-ED1 is adjusted during the price control period. The most significant of those adjustments are: • Inflation True-Up - The base demand revenue for the RIIO-ED1 period was set based on 2012/13 prices. Therefore an inflation factor as determined by forecasted RPI, provided by HM Treasury, is applied to base demand revenue. Forecasted RPI is trued up to actuals and affects future base demand revenue two regulatory years later. This revenue change is called the "TRU" adjustment. • Annual Iteration Process (AIP) - The RIIO-ED1 price control period also includes an AIP. This will allow future base demand revenues agreed with the regulator as part of the price control review, to be updated during the price control period for financial adjustments including tax, pensions, cost of debt, legacy price control adjustments from preceding price control periods and adjustments relating to actual and allowed total expenditure together with the Totex Incentive Mechanism (TIM). Under the TIM, WPD's DNOs are able to retain 70% of any amounts not spent against the RIIO-ED1 plan and bear 70% of any over-spends. The AIP calculates an incremental change to base demand revenue, known as the "MOD" adjustment. As both MOD and TRU are changes to future base demand revenues as determined by Ofgem, these adjustments are recognized as a component of revenues in future years in which service is provided and revenues are collected or returned to customers. In addition to base demand revenue, certain other items are added or subtracted to arrive at allowed revenue. The most significant of these are: • Incentives - Ofgem has established incentives to provide opportunities for DNO's to enhance overall returns by improving network efficiency, reliability and customer service. These incentives can result in an increase or reduction in revenues based on incentives or penalties for actual performance against pre-established targets based on past performance. The annual incentives and penalties are reflected in customers' rates on a two -year lag from the time they are earned and/or assessed. Incentive revenues and penalties are included in revenues when they are billed to customers. • Correction Factor - During the current price control period, WPD sets its tariffs to recover allowed revenue. However, in any fiscal period, WPD's revenue could be negatively affected if its tariffs and the volume delivered do not fully recover the revenue allowed for a particular period. Conversely, WPD could also over-recover revenue. Over and under-recoveries are subtracted from or added to allowed revenue in future years when they are billed to customers, known as the "Correction Factor" or "K-factor." Over and under-recovered amounts arising for the periods beginning with the 2014/15 regulatory year and refunded/recovered under RIIO-ED1 will be refunded/recovered on a two year lag (previously one year ). Therefore the 2014/15 over/under-recovery adjustment occurred in the 2016/17 regulatory year.
Accounts Receivable	Accounts Receivable (All Registrants) Accounts receivable are reported on the Balance Sheets at the gross outstanding amount adjusted for an allowance for doubtful accounts. Allowance for Doubtful Accounts Accounts receivable collectability is evaluated using a combination of factors, including past due status based on contractual terms, trends in write-offs and the age of the receivable. Specific events, such as bankruptcies, are also considered when applicable. Adjustments to the allowance for doubtful accounts are made when necessary based on the results of analysis, the aging of receivables and historical and industry trends. Accounts receivable are written off in the period in which the receivable is deemed uncollectible.
Cash	Cash (All Registrants) Cash Equivalents All highly liquid investments with original maturities of three months or less are considered to be cash equivalents. (PPL and PPL Electric) Restricted Cash and Cash Equivalents Bank deposits and other cash equivalents that are restricted by agreement or that have been clearly designated for a specific purpose are classified as restricted cash and cash equivalents. The change in restricted cash and cash equivalents is reported as an investing activity on the Statements of Cash Flows. On the Balance Sheets, the current portion of restricted cash and cash equivalents is included in "Other current assets," while the noncurrent portion is included in "Other noncurrent assets."
Fair Value Measurements	Fair Value Measurements The Registrants value certain financial and nonfinancial assets and liabilities at fair value. Generally, the most significant fair value measurements relate to price risk management assets and liabilities, investments in securities in defined benefit plans, and cash and cash equivalents. PPL and its subsidiaries use, as appropriate, a market approach (generally, data from market transactions), an income approach (generally, present value techniques and option-pricing models) and/or a cost approach (generally, replacement cost) to measure the fair value of an asset or liability. These valuation approaches incorporate inputs such as observable, independent market data and/or unobservable data that management believes are predicated on the assumptions market participants would use to price an asset or liability. These inputs may incorporate, as applicable, certain risks such as nonperformance risk, which includes credit risk. The Registrants classify fair value measurements within one of three levels in the fair value hierarchy. The level assigned to a fair value measurement is based on the lowest level input that is significant to the fair value measurement in its entirety. The three levels of the fair value hierarchy are as follows: • Level 1 - quoted prices (unadjusted) in active markets for identical assets or liabilities that are accessible at the measurement date. Active markets are those in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. • Level 2 - inputs other than quoted prices included within Level 1 that are either directly or indirectly observable for substantially the full term of the asset or liability. • Level 3 - unobservable inputs that management believes are predicated on the assumptions market participants would use to measure the asset or liability at fair value. Assessing the significance of a particular input requires judgment that considers factors specific to the asset or liability. As such, the Registrants' assessment of the significance of a particular input may affect how the assets and liabilities are classified within the fair value hierarchy.
Investments	Investments (All Registrants) Generally, the original maturity date of an investment and management's intent and ability to sell an investment prior to its original maturity determine the classification of investments as either short-term or long-term. Investments that would otherwise be classified as short-term, but are restricted as to withdrawal or use for other than current operations or are clearly designated for expenditure in the acquisition or construction of noncurrent assets or for the liquidation of long-term debts, are classified as long-term. Short-term Investments Short-term investments generally include certain deposits as well as securities that are considered highly liquid or provide for periodic reset of interest rates. Investments with original maturities greater than three months and less than a year, as well as investments with original maturities of greater than a year that management has the ability and intent to sell within a year, are included in "Other current assets" on the Balance Sheets. (PPL, LKE, LG&E and KU) Cost Method Investment LG&E and KU each have an investment in OVEC, which is accounted for using the cost method. The investment is recorded in "Other noncurrent assets" on the PPL, LKE, LG&E and KU Balance Sheets. LG&E and KU and ten other electric utilities are equity owners of OVEC. OVEC's power is currently supplied to LG&E and KU and 11 other companies affiliated with the various owners. LG&E and KU own 5.63% and 2.5% of OVEC's common stock. Pursuant to a power purchase agreement, LG&E and KU are contractually entitled to their ownership percentage of OVEC's output, which is approximately 120 MW for LG&E and approximately 53 MW for KU. LG&E's and KU's combined investment in OVEC is not significant. The direct exposure to loss as a result of LG&E's and KU's involvement with OVEC is generally limited to the value of their investments; however, LG&E and KU are conditionally responsible for a pro-rata share of certain OVEC obligations, pursuant to their power purchase contract with OVEC. As part of PPL's acquisition of LKE, the value of the power purchase contract was recorded as an intangible asset with an offsetting regulatory liability, both of which are being amortized using the units-of-production method until March 2026. See Notes 6, 13 and 18 for additional discussion of the power purchase agreement.
Property, Plant and Equipment	Depreciation (All Registrants) Depreciation is recorded over the estimated useful lives of property using various methods including the straight-line, composite and group methods. When a component of PP&E that was depreciated under the composite or group method is retired, the original cost is charged to accumulated depreciation. When all or a significant portion of an operating unit that was depreciated under the composite or group method is retired or sold, the property and the related accumulated depreciation account is reduced and any gain or loss is included in income, unless otherwise required by regulators. Property, Plant and Equipment (All Registrants) PP&E is recorded at original cost, unless impaired. PP&E acquired in business combinations is recorded at fair value at the time of acquisition. If impaired, the asset is written down to fair value at that time, which becomes the new cost basis of the asset. Original cost for constructed assets includes material, labor, contractor costs, certain overheads and financing costs, where applicable. The cost of repairs and minor replacements are charged to expense as incurred. The Registrants record costs associated with planned major maintenance projects in the period in which the costs are incurred. No costs associated with planned major maintenance projects are accrued to PP&E in advance of the period in which the work is performed. LG&E and KU accrue costs of removal net of estimated salvage value through depreciation, which is included in the calculation of customer rates over the assets' depreciable lives in accordance with regulatory practices. Cost of removal amounts accrued through depreciation rates are accumulated as a regulatory liability until the removal costs are incurred. For LKE, LG&E and KU, all ARO depreciation expenses are reclassified to a regulatory asset. See "Asset Retirement Obligations" below and Note 6 for additional information. PPL Electric records net costs of removal when incurred as a regulatory asset. The regulatory asset is subsequently amortized through depreciation over a five -year period, which is recoverable in customer rates in accordance with regulatory practices. AFUDC is capitalized at PPL Electric as part of the construction costs for cost-based rate-regulated projects for which a return on such costs is recovered after the project is placed in service. The debt component of AFUDC is credited to "Interest Expense" and the equity component is credited to "Other Income (Expense) - net" on the Statements of Income. LG&E and KU generally do not record AFUDC, except for certain instances in KU's FERC approved rates charged to its municipal customers, as a return is provided on construction work in progress. (PPL) PPL capitalizes interest costs as part of construction costs.
Goodwill and Other Intangible Assets	(All Registrants) Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price paid over the fair value of the identifiable net assets acquired in a business combination. Other acquired intangible assets are initially measured based on their fair value. Intangibles that have finite useful lives are amortized over their useful lives based upon the pattern in which the economic benefits of the intangible assets are consumed or otherwise used. Costs incurred to obtain an initial license and renew or extend terms of licenses are capitalized as intangible assets. When determining the useful life of an intangible asset, including intangible assets that are renewed or extended, PPL and its subsidiaries consider: • the expected use of the asset; • the expected useful life of other assets to which the useful life of the intangible asset may relate; • legal, regulatory, or contractual provisions that may limit the useful life; • the company's historical experience as evidence of its ability to support renewal or extension; • the effects of obsolescence, demand, competition, and other economic factors; and, • the level of maintenance expenditures required to obtain the expected future cash flows from the asset.
Asset Impairment (Excluding Investments)	Asset Impairment (Excluding Investments) The Registrants review long-lived assets that are subject to depreciation or amortization, including finite-lived intangibles, for impairment when events or circumstances indicate carrying amounts may not be recoverable. A long-lived asset classified as held and used is impaired when the carrying amount of the asset exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. If impaired, the asset's carrying value is written down to its fair value. A long-lived asset classified as held for sale is impaired when the carrying amount of the asset (disposal group) exceeds its fair value less cost to sell. If impaired, the asset's (disposal group's) carrying value is written down to its fair value less cost to sell. PPL, LKE, LG&E and KU review goodwill for impairment at the reporting unit level annually or more frequently when events or circumstances indicate that the carrying amount of a reporting unit may be greater than the unit's fair value. Additionally, goodwill must be tested for impairment in circumstances when a portion of goodwill has been allocated to a business to be disposed. PPL's, LKE's, LG&E's and KU's reporting units are at the operating segment level. PPL, LKE, LG&E and KU may elect either to initially make a qualitative evaluation about the likelihood of an impairment of goodwill or to bypass the qualitative evaluation and test goodwill for impairment using a two-step quantitative test. If the qualitative evaluation (referred to as "step zero") is elected and the assessment results in a determination that it is not more likely than not that the fair value of a reporting unit is less than the carrying amount, the two-step quantitative impairment test is not necessary. However, the quantitative impairment test is required if management concludes it is more likely than not that the fair value of a reporting unit is less than the carrying amount based on the step zero assessment. If the carrying amount of the reporting unit, including goodwill, exceeds its fair value, the implied fair value of goodwill must be calculated in the same manner as goodwill in a business combination. The fair value of a reporting unit is allocated to all assets and liabilities of that unit as if the reporting unit had been acquired in a business combination. The excess of the fair value of the reporting unit over the amounts assigned to its assets and liabilities is the implied fair value of goodwill. If the implied fair value of goodwill is less than the carrying amount, goodwill is written down to its implied fair value. PPL (for its U.K. Regulated and Kentucky Regulated segments), and individually, LKE, LG&E and KU elected to perform the qualitative step zero evaluation of goodwill as of October 1, 2017. These evaluations considered the excess of fair value over the carrying value of each reporting unit that was calculated during step one of the quantitative impairment tests performed in the fourth quarter of 2015, and the relevant events and circumstances that occurred since those tests were performed including: • current year financial performance versus the prior year; • changes in planned capital expenditures; • the consistency of forecasted free cash flows; • earnings quality and sustainability; • changes in market participant discount rates; • changes in long-term growth rates • changes in PPL's market capitalization; and, • the overall economic and regulatory environments in which these regulated entities operate. Based on these evaluations, management concluded it was not more likely than not that the fair value of these reporting units was less than their carrying value. As such, the two-step quantitative impairment test was not performed and no impairment was recognized.
Asset Retirement Obligations	Asset Retirement Obligations PPL and its subsidiaries record liabilities to reflect various legal obligations associated with the retirement of long-lived assets. Initially, this obligation is measured at fair value and offset with an increase in the value of the capitalized asset, which is depreciated over the asset's useful life. Until the obligation is settled, the liability is increased through the recognition of accretion expense classified within "Other operation and maintenance" on the Statements of Income to reflect changes in the obligation due to the passage of time. For LKE, LG&E and KU, all ARO accretion and depreciation expenses are reclassified as a regulatory asset. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, at the time of retirement, the related ARO regulatory asset is offset against the associated cost of removal regulatory liability, PP&E and ARO liability. Estimated ARO costs and settlement dates, which affect the carrying value of the ARO and the related capitalized asset, are reviewed periodically to ensure that any material changes are incorporated into the latest estimate of the ARO. Any change to the capitalized asset, positive or negative, is generally amortized over the remaining life of the associated long-lived asset. See Note 6 and Note 19 for additional information on AROs.
Compensation and Benefits	Compensation and Benefits Defined Benefits (All Registrants) Certain PPL subsidiaries sponsor various defined benefit pension and other postretirement plans. An asset or liability is recorded to recognize the funded status of all defined benefit plans with an offsetting entry to AOCI or, for LG&E, KU and PPL Electric, to regulatory assets or liabilities. Consequently, the funded status of all defined benefit plans is fully recognized on the Balance Sheets. The expected return on plan assets is determined based on a market-related value of plan assets, which is calculated by rolling forward the prior year market-related value with contributions, disbursements and long-term expected return on investments. One-fifth of the difference between the actual value and the expected value is added (or subtracted if negative) to the expected value to determine the new market-related value. PPL uses an accelerated amortization method for the recognition of gains and losses for its defined benefit pension plans. Under the accelerated method, actuarial gains and losses in excess of 30% of the plan's projected benefit obligation are amortized on a straight-line basis over one-half of the expected average remaining service of active plan participants. Actuarial gains and losses in excess of 10% of the greater of the plan's projected benefit obligation or the market-related value of plan assets and less than 30% of the plan's projected benefit obligation are amortized on a straight-line basis over the expected average remaining service period of active plan participants. See Note 6 for a discussion of the regulatory treatment of defined benefit costs and Note 11 for a discussion of defined benefits. Discount Rate Change for U.K. Pension Plans (PPL) In selecting the discount rate for its U.K. pension plans, WPD historically used a single weighted-average discount rate in the calculation of net periodic defined benefit cost. WPD began using individual spot rates to measure service cost and interest cost for the calculation of net periodic defined benefit cost in 2016. In 2016, this change in discount rate resulted in lower net periodic defined benefit costs recognized on PPL's Statement of Income of $43 million ( $34 million after-tax or $0.05 per share). See Note 11 for additional information. Stock-Based Compensation (PPL, PPL Electric and LKE) PPL has several stock-based compensation plans for purposes of granting stock options, restricted stock, restricted stock units and performance units to certain employees as well as stock units and restricted stock units to directors. PPL grants most stock-based awards in the first quarter of each year. PPL and its subsidiaries recognize compensation expense for stock-based awards based on the fair value method. Forfeitures of awards are recognized when they occur. See Note 10 for a discussion of stock-based compensation. All awards are recorded as equity or a liability on the Balance Sheets. Stock-based compensation is primarily included in "Other operation and maintenance" on the Statements of Income. Stock-based compensation expense for PPL Electric and LKE includes an allocation of PPL Services' expense.
Income Taxes	Taxes Income Taxes (All Registrants) PPL and its domestic subsidiaries file a consolidated U.S. federal income tax return. The Registrants have completed or made reasonable estimates of the effects of the TCJA and reflected these amounts in their December 31, 2017 financial statements. The Registrants continue to evaluate the application of the TCJA and have used significant management judgment to make certain assumptions concerning the application of various components of the law in the calculation of 2017 income tax expense. The current and deferred components of the income tax expense calculations that the Registrants consider provisional due to uncertainty either with respect to the technical application of the law or the quantification of the impact of the law include (but are not limited to): tax depreciation, deductible executive compensation, and the accumulated foreign earnings used to calculate the deemed dividend included in PPL's taxable income in 2017 along with the impact of associated foreign tax credits and related valuation allowances. The Registrants believe that classification of these items as provisional is appropriate. The Registrants have accounted for these items based on their interpretation of the TCJA. Further interpretive guidance on the TCJA from the IRS, Treasury, the Joint Committee on Taxation through its "Blue Book" or from Congress in the form of Technical Corrections may differ from the Registrants' interpretation of the TCJA. Significant management judgment is also required in developing the Registrants' provision for income taxes, primarily due to the uncertainty related to tax positions taken or expected to be taken in tax returns, valuation allowances on deferred tax assets and whether the undistributed earnings of WPD are considered indefinitely reinvested. Significant management judgment is also required to determine the amount of benefit to be recognized in relation to an uncertain tax position. The Registrants use a two-step process to evaluate tax positions. The first step requires an entity to determine whether, based on the technical merits supporting a particular tax position, it is more likely than not (greater than a 50% chance) that the tax position will be sustained. This determination assumes that the relevant taxing authority will examine the tax position and is aware of all the relevant facts surrounding the tax position. The second step requires an entity to recognize in the financial statements the benefit of a tax position that meets the more-likely-than-not recognition criterion. The benefit recognized is measured at the largest amount of benefit that has a likelihood of realization, upon settlement, that exceeds 50% . The amounts ultimately paid upon resolution of issues raised by taxing authorities may differ materially from the amounts accrued and may materially impact the financial statements of the Registrants in future periods. Deferred income taxes reflect the net future tax effects of temporary differences between the carrying amounts of assets and liabilities for accounting purposes and their basis for income tax purposes, as well as the tax effects of net operating losses and tax credit carryforwards. The Registrants record valuation allowances to reduce deferred tax assets to the amounts that are more likely than not to be realized. The Registrants consider the reversal of temporary differences, future taxable income and ongoing prudent and feasible tax planning strategies in initially recording and subsequently reevaluating the need for valuation allowances. If the Registrants determine that they are able to realize deferred tax assets in the future in excess of recorded net deferred tax assets, adjustments to the valuation allowances increase income by reducing tax expense in the period that such determination is made. Likewise, if the Registrants determine that they are not able to realize all or part of net deferred tax assets in the future, adjustments to the valuation allowances would decrease income by increasing tax expense in the period that such determination is made. The Registrants defer investment tax credits when the credits are utilized and amortize the deferred amounts over the average lives of the related assets. The Registrants recognize interest and penalties in "Income Taxes" on their Statements of Income. See Note 5 for additional discussion regarding income taxes, including the impact of the TCJA and management's conclusion that the undistributed earnings of WPD are considered indefinitely reinvested. The provision for PPL's, PPL Electric's, LKE's, LG&E's and KU's deferred income taxes for regulatory assets and liabilities is based upon the ratemaking principles reflected in rates established by the regulators. The difference in the provision for deferred income taxes for regulatory assets and liabilities and the amount that otherwise would be recorded under GAAP is deferred and included on the Balance Sheets in noncurrent "Regulatory assets" or "Regulatory liabilities."
Taxes, Other Than Income	Taxes, Other Than Income (All Registrants) The Registrants present sales taxes in "Other current liabilities" and PPL presents value-added taxes in "Taxes" on the Balance Sheets. These taxes are not reflected on the Statements of Income. See Note 5 for details on taxes included in "Taxes, other than income" on the Statements of Income.
Leases	(All Registrants) Leases The Registrants evaluate whether arrangements entered into contain leases for accounting purposes. See Note 9 for additional information.
Fuel, Materials and Supplies	Fuel, Materials and Supplies Fuel, natural gas stored underground and materials and supplies are valued using the average cost method. Fuel costs for electric generation are charged to expense as used. For LG&E, natural gas supply costs are charged to expense as delivered to the distribution system. See Note 6 for further discussion of the fuel adjustment clause and gas supply clause.
Guarantees	Guarantees (All Registrants) Generally, the initial measurement of a guarantee liability is the fair value of the guarantee at its inception. However, there are certain guarantees excluded from the scope of accounting guidance and other guarantees that are not subject to the initial recognition and measurement provisions of accounting guidance that only require disclosure. See Note 13 for further discussion of recorded and unrecorded guarantees.
Treasury Stock	Treasury Stock (PPL) PPL restores all shares of common stock acquired to authorized but unissued shares of common stock upon acquisition.
Foreign Currency Translation and Transactions	Foreign Currency Translation and Transactions (PPL) WPD's functional currency is the GBP, which is the local currency in the U.K. As such, assets and liabilities are translated to U.S. dollars at the exchange rates on the date of consolidation and related revenues and expenses are generally translated at average exchange rates prevailing during the period included in PPL's results of operations. Adjustments resulting from foreign currency translation are recorded in AOCI. Gains or losses relating to foreign currency transactions are recognized in "Other Income (Expense) - net" on the Statements of Income. See Note 15 for additional information.
PPL Electric Utilities Corp [Member]
Summary of Significant Accounting Policies [Line Items]
Business and Consolidation	PPL Electric is a cost-based rate-regulated utility subsidiary of PPL. PPL Electric's principal business is the transmission and distribution of electricity to serve retail customers in its franchised territory in eastern and central Pennsylvania and the regulated supply of electricity to retail customers in that territory as a PLR.
Price Risk Management	(PPL and PPL Electric) To meet its obligation as a PLR to its customers, PPL Electric has entered into certain contracts that meet the definition of a derivative. However, NPNS has been elected for these contracts. See Notes 16 and 17 for additional information on derivatives.
Cash	Restricted Cash and Cash Equivalents Bank deposits and other cash equivalents that are restricted by agreement or that have been clearly designated for a specific purpose are classified as restricted cash and cash equivalents. The change in restricted cash and cash equivalents is reported as an investing activity on the Statements of Cash Flows. On the Balance Sheets, the current portion of restricted cash and cash equivalents is included in "Other current assets," while the noncurrent portion is included in "Other noncurrent assets."
Compensation and Benefits	Stock-Based Compensation (PPL, PPL Electric and LKE) PPL has several stock-based compensation plans for purposes of granting stock options, restricted stock, restricted stock units and performance units to certain employees as well as stock units and restricted stock units to directors. PPL grants most stock-based awards in the first quarter of each year. PPL and its subsidiaries recognize compensation expense for stock-based awards based on the fair value method. Forfeitures of awards are recognized when they occur. See Note 10 for a discussion of stock-based compensation. All awards are recorded as equity or a liability on the Balance Sheets. Stock-based compensation is primarily included in "Other operation and maintenance" on the Statements of Income. Stock-based compensation expense for PPL Electric and LKE includes an allocation of PPL Services' expense.
Income Taxes	(PPL Electric, LKE, LG&E and KU) The income tax provision for PPL Electric, LG&E and KU is calculated in accordance with an intercompany tax sharing agreement, which provides that taxable income be calculated as if PPL Electric, LG&E, KU and any domestic subsidiaries each filed a separate return. Tax benefits are not shared between companies. The entity that generates a tax benefit is the entity that is entitled to the tax benefit. The effect of PPL filing a consolidated tax return is taken into account in the settlement of current taxes and the recognition of deferred taxes.
LG And E And KU Energy LLC [Member]
Summary of Significant Accounting Policies [Line Items]
Business and Consolidation	LKE is a utility holding company with cost-based rate-regulated utility operations through its subsidiaries, LG&E and KU. LG&E and KU are engaged in the generation, transmission, distribution and sale of electricity. LG&E also engages in the distribution and sale of natural gas. LG&E and KU maintain their separate identities and serve customers in Kentucky under their respective names. KU also serves customers in Virginia under the Old Dominion Power name and in Tennessee under the KU name.
Investments	Cost Method Investment LG&E and KU each have an investment in OVEC, which is accounted for using the cost method. The investment is recorded in "Other noncurrent assets" on the PPL, LKE, LG&E and KU Balance Sheets. LG&E and KU and ten other electric utilities are equity owners of OVEC. OVEC's power is currently supplied to LG&E and KU and 11 other companies affiliated with the various owners. LG&E and KU own 5.63% and 2.5% of OVEC's common stock. Pursuant to a power purchase agreement, LG&E and KU are contractually entitled to their ownership percentage of OVEC's output, which is approximately 120 MW for LG&E and approximately 53 MW for KU. LG&E's and KU's combined investment in OVEC is not significant. The direct exposure to loss as a result of LG&E's and KU's involvement with OVEC is generally limited to the value of their investments; however, LG&E and KU are conditionally responsible for a pro-rata share of certain OVEC obligations, pursuant to their power purchase contract with OVEC. As part of PPL's acquisition of LKE, the value of the power purchase contract was recorded as an intangible asset with an offsetting regulatory liability, both of which are being amortized using the units-of-production method until March 2026. See Notes 6, 13 and 18 for additional discussion of the power purchase agreement.
Asset Retirement Obligations	Asset Retirement Obligations PPL and its subsidiaries record liabilities to reflect various legal obligations associated with the retirement of long-lived assets. Initially, this obligation is measured at fair value and offset with an increase in the value of the capitalized asset, which is depreciated over the asset's useful life. Until the obligation is settled, the liability is increased through the recognition of accretion expense classified within "Other operation and maintenance" on the Statements of Income to reflect changes in the obligation due to the passage of time. For LKE, LG&E and KU, all ARO accretion and depreciation expenses are reclassified as a regulatory asset. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, at the time of retirement, the related ARO regulatory asset is offset against the associated cost of removal regulatory liability, PP&E and ARO liability. Estimated ARO costs and settlement dates, which affect the carrying value of the ARO and the related capitalized asset, are reviewed periodically to ensure that any material changes are incorporated into the latest estimate of the ARO. Any change to the capitalized asset, positive or negative, is generally amortized over the remaining life of the associated long-lived asset. See Note 6 and Note 19 for additional information on AROs.
Compensation and Benefits	Stock-Based Compensation (PPL, PPL Electric and LKE) PPL has several stock-based compensation plans for purposes of granting stock options, restricted stock, restricted stock units and performance units to certain employees as well as stock units and restricted stock units to directors. PPL grants most stock-based awards in the first quarter of each year. PPL and its subsidiaries recognize compensation expense for stock-based awards based on the fair value method. Forfeitures of awards are recognized when they occur. See Note 10 for a discussion of stock-based compensation. All awards are recorded as equity or a liability on the Balance Sheets. Stock-based compensation is primarily included in "Other operation and maintenance" on the Statements of Income. Stock-based compensation expense for PPL Electric and LKE includes an allocation of PPL Services' expense.
Income Taxes	(PPL Electric, LKE, LG&E and KU) The income tax provision for PPL Electric, LG&E and KU is calculated in accordance with an intercompany tax sharing agreement, which provides that taxable income be calculated as if PPL Electric, LG&E, KU and any domestic subsidiaries each filed a separate return. Tax benefits are not shared between companies. The entity that generates a tax benefit is the entity that is entitled to the tax benefit. The effect of PPL filing a consolidated tax return is taken into account in the settlement of current taxes and the recognition of deferred taxes.
Louisville Gas And Electric Co [Member]
Summary of Significant Accounting Policies [Line Items]
Business and Consolidation	LKE is a utility holding company with cost-based rate-regulated utility operations through its subsidiaries, LG&E and KU. LG&E and KU are engaged in the generation, transmission, distribution and sale of electricity. LG&E also engages in the distribution and sale of natural gas. LG&E and KU maintain their separate identities and serve customers in Kentucky under their respective names. KU also serves customers in Virginia under the Old Dominion Power name and in Tennessee under the KU name.
Investments	Cost Method Investment LG&E and KU each have an investment in OVEC, which is accounted for using the cost method. The investment is recorded in "Other noncurrent assets" on the PPL, LKE, LG&E and KU Balance Sheets. LG&E and KU and ten other electric utilities are equity owners of OVEC. OVEC's power is currently supplied to LG&E and KU and 11 other companies affiliated with the various owners. LG&E and KU own 5.63% and 2.5% of OVEC's common stock. Pursuant to a power purchase agreement, LG&E and KU are contractually entitled to their ownership percentage of OVEC's output, which is approximately 120 MW for LG&E and approximately 53 MW for KU. LG&E's and KU's combined investment in OVEC is not significant. The direct exposure to loss as a result of LG&E's and KU's involvement with OVEC is generally limited to the value of their investments; however, LG&E and KU are conditionally responsible for a pro-rata share of certain OVEC obligations, pursuant to their power purchase contract with OVEC. As part of PPL's acquisition of LKE, the value of the power purchase contract was recorded as an intangible asset with an offsetting regulatory liability, both of which are being amortized using the units-of-production method until March 2026. See Notes 6, 13 and 18 for additional discussion of the power purchase agreement.
Asset Retirement Obligations	Asset Retirement Obligations PPL and its subsidiaries record liabilities to reflect various legal obligations associated with the retirement of long-lived assets. Initially, this obligation is measured at fair value and offset with an increase in the value of the capitalized asset, which is depreciated over the asset's useful life. Until the obligation is settled, the liability is increased through the recognition of accretion expense classified within "Other operation and maintenance" on the Statements of Income to reflect changes in the obligation due to the passage of time. For LKE, LG&E and KU, all ARO accretion and depreciation expenses are reclassified as a regulatory asset. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, at the time of retirement, the related ARO regulatory asset is offset against the associated cost of removal regulatory liability, PP&E and ARO liability. Estimated ARO costs and settlement dates, which affect the carrying value of the ARO and the related capitalized asset, are reviewed periodically to ensure that any material changes are incorporated into the latest estimate of the ARO. Any change to the capitalized asset, positive or negative, is generally amortized over the remaining life of the associated long-lived asset. See Note 6 and Note 19 for additional information on AROs.
Income Taxes	(PPL Electric, LKE, LG&E and KU) The income tax provision for PPL Electric, LG&E and KU is calculated in accordance with an intercompany tax sharing agreement, which provides that taxable income be calculated as if PPL Electric, LG&E, KU and any domestic subsidiaries each filed a separate return. Tax benefits are not shared between companies. The entity that generates a tax benefit is the entity that is entitled to the tax benefit. The effect of PPL filing a consolidated tax return is taken into account in the settlement of current taxes and the recognition of deferred taxes.
Kentucky Utilities Co [Member]
Summary of Significant Accounting Policies [Line Items]
Business and Consolidation	LKE is a utility holding company with cost-based rate-regulated utility operations through its subsidiaries, LG&E and KU. LG&E and KU are engaged in the generation, transmission, distribution and sale of electricity. LG&E also engages in the distribution and sale of natural gas. LG&E and KU maintain their separate identities and serve customers in Kentucky under their respective names. KU also serves customers in Virginia under the Old Dominion Power name and in Tennessee under the KU name.
Investments	Cost Method Investment LG&E and KU each have an investment in OVEC, which is accounted for using the cost method. The investment is recorded in "Other noncurrent assets" on the PPL, LKE, LG&E and KU Balance Sheets. LG&E and KU and ten other electric utilities are equity owners of OVEC. OVEC's power is currently supplied to LG&E and KU and 11 other companies affiliated with the various owners. LG&E and KU own 5.63% and 2.5% of OVEC's common stock. Pursuant to a power purchase agreement, LG&E and KU are contractually entitled to their ownership percentage of OVEC's output, which is approximately 120 MW for LG&E and approximately 53 MW for KU. LG&E's and KU's combined investment in OVEC is not significant. The direct exposure to loss as a result of LG&E's and KU's involvement with OVEC is generally limited to the value of their investments; however, LG&E and KU are conditionally responsible for a pro-rata share of certain OVEC obligations, pursuant to their power purchase contract with OVEC. As part of PPL's acquisition of LKE, the value of the power purchase contract was recorded as an intangible asset with an offsetting regulatory liability, both of which are being amortized using the units-of-production method until March 2026. See Notes 6, 13 and 18 for additional discussion of the power purchase agreement.
Asset Retirement Obligations	Asset Retirement Obligations PPL and its subsidiaries record liabilities to reflect various legal obligations associated with the retirement of long-lived assets. Initially, this obligation is measured at fair value and offset with an increase in the value of the capitalized asset, which is depreciated over the asset's useful life. Until the obligation is settled, the liability is increased through the recognition of accretion expense classified within "Other operation and maintenance" on the Statements of Income to reflect changes in the obligation due to the passage of time. For LKE, LG&E and KU, all ARO accretion and depreciation expenses are reclassified as a regulatory asset. ARO regulatory assets associated with certain CCR projects are amortized to expense in accordance with regulatory approvals. For other AROs, at the time of retirement, the related ARO regulatory asset is offset against the associated cost of removal regulatory liability, PP&E and ARO liability. Estimated ARO costs and settlement dates, which affect the carrying value of the ARO and the related capitalized asset, are reviewed periodically to ensure that any material changes are incorporated into the latest estimate of the ARO. Any change to the capitalized asset, positive or negative, is generally amortized over the remaining life of the associated long-lived asset. See Note 6 and Note 19 for additional information on AROs.
Income Taxes	(PPL Electric, LKE, LG&E and KU) The income tax provision for PPL Electric, LG&E and KU is calculated in accordance with an intercompany tax sharing agreement, which provides that taxable income be calculated as if PPL Electric, LG&E, KU and any domestic subsidiaries each filed a separate return. Tax benefits are not shared between companies. The entity that generates a tax benefit is the entity that is entitled to the tax benefit. The effect of PPL filing a consolidated tax return is taken into account in the settlement of current taxes and the recognition of deferred taxes.

Fair Value Measurements (Polici

Fair Value Measurements (Policies)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	The fair value of a group of financial assets and liabilities is measured on a net basis. Transfers between levels are recognized at end-of-reporting-period values.

Derivative Instruments and He35

Derivative Instruments and Hedging Activities (Policies)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivatives	Price Risk Management (All Registrants) Interest rate contracts are used to hedge exposure to changes in the fair value of debt instruments and to hedge exposure to variability in expected cash flows associated with existing floating-rate debt instruments or forecasted fixed-rate issuances of debt. Foreign currency exchange contracts are used to hedge foreign currency exposures, primarily associated with PPL's investments in U.K. subsidiaries. Similar derivatives may receive different accounting treatment, depending on management's intended use and documentation. Certain contracts may not meet the definition of a derivative because they lack a notional amount or a net settlement provision. In cases where there is no net settlement provision, markets are periodically assessed to determine whether market mechanisms have evolved that would facilitate net settlement. Certain derivative contracts may be excluded from the requirements of derivative accounting treatment because NPNS has been elected. These contracts are accounted for using accrual accounting. Contracts that have been classified as derivative contracts are reflected on the balance sheets at fair value. The portion of derivative positions that deliver within a year are included in "Current Assets" and "Current Liabilities," while the portion of derivative positions that deliver beyond a year are recorded in "Other Noncurrent Assets" and "Deferred Credits and Other Noncurrent Liabilities." Cash inflows and outflows related to derivative instruments are included as a component of operating, investing or financing activities on the Statements of Cash Flows, depending on the classification of the hedged items. PPL and its subsidiaries have elected not to offset net derivative positions against the right to reclaim cash collateral (a receivable) or the obligation to return cash collateral (a payable) under master netting arrangements. (PPL) Processes exist that allow for subsequent review and validation of the contract information as it relates to interest rate and foreign currency derivatives. The accounting department provides the treasury department with guidelines on appropriate accounting classifications for various contract types and strategies. Examples of accounting guidelines provided to the treasury department staff include, but are not limited to: • Transactions to lock in an interest rate prior to a debt issuance can be designated as cash flow hedges, to the extent the forecasted debt issuances remain probable of occurring. • Cross-currency transactions to hedge interest and principal repayments can be designated as cash flow hedges. • Transactions to hedge fluctuations in the fair value of existing debt can be designated as fair value hedges. • Transactions to hedge the value of a net investment of foreign operations can be designated as net investment hedges. • Derivative transactions that do not qualify for cash flow or net investment hedge treatment are marked to fair value through earnings. These transactions generally include foreign currency forwards and options to hedge GBP-denominated earnings translation risk associated with PPL's U.K. subsidiaries that report their financial statements in GBP. As such, these transactions reduce earnings volatility due solely to changes in foreign currency exchange rates. (All Registrants) • Derivative transactions may be marked to fair value through regulatory assets/liabilities at PPL Electric, LG&E and KU if approved by the appropriate regulatory body. These transactions generally include the effect of interest rate swaps that are included in customer rates. (PPL and PPL Electric) To meet its obligation as a PLR to its customers, PPL Electric has entered into certain contracts that meet the definition of a derivative. However, NPNS has been elected for these contracts. See Notes 16 and 17 for additional information on derivatives. All derivative instruments are recorded at fair value on the Balance Sheet as an asset or liability unless NPNS is elected. NPNS contracts for PPL and PPL Electric include certain full-requirement purchase contracts and other physical purchase contracts. Changes in the fair value of derivatives not designated as NPNS are recognized in earnings unless specific hedge accounting criteria are met and designated as such, except for the changes in fair values of LG&E's interest rate swaps that are recognized as regulatory assets or regulatory liabilities.
Price Risk Management	Net derivative positions on the balance sheets are not offset against the right to reclaim cash collateral (a receivable) or the obligation to return cash collateral (a payable) under master netting arrangements.

Summary of Significant Accoun36

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Summary of Significant Accounting Policies [Line Items]
Schedule of Utility Revenue	For the years ended December 31, the Statements of Income "Operating Revenues" line item contains revenue from the following: 2017 2016 2015 Domestic electric and gas revenues (a) $ 5,351 $ 5,297 $ 5,239 U.K. operating revenues (b) 2,091 2,207 2,410 Domestic - other 5 13 20 Total $ 7,447 $ 7,517 $ 7,669 (a) Represents revenues from cost-based rate-regulated generation, transmission and/or distribution in Pennsylvania, Kentucky, Virginia and Tennessee, including regulated wholesale revenue. (b) Primarily represents regulated electricity distribution revenues from the operation of WPD's distribution networks.
Schedule of Valuation and Qualifying Accounts Disclosure	The changes in the allowance for doubtful accounts were: Additions Balance at Beginning of Period Charged to Income Charged to Other Accounts Deductions (a) Balance at End of Period PPL 2017 $ 54 $ 28 $ (1 ) $ 30 $ 51 2016 41 44 — 31 54 2015 44 49 (2 ) 50 41 PPL Electric 2017 $ 28 $ 18 $ — $ 22 $ 24 2016 16 35 — 23 28 2015 17 39 — 40 16 Additions Balance at Beginning of Period Charged to Income Charged to Other Accounts Deductions (a) Balance at End of Period LKE 2017 $ 24 $ 8 $ (1 ) $ 6 $ 25 2016 23 8 — 7 24 2015 25 9 (2 ) 9 23 LG&E 2017 $ 2 $ 2 $ (1 ) $ 2 $ 1 2016 1 2 1 2 2 2015 2 2 — 3 1 KU 2017 $ 2 $ 4 $ (1 ) $ 4 $ 1 2016 2 4 — 4 2 2015 2 5 — 5 2 (a) Primarily related to uncollectible accounts written off.
Schedule of Restricted Cash and Cash Equivalents	At December 31, the balances of restricted cash and cash equivalents included the following: PPL PPL Electric 2017 2016 2017 2016 Low carbon network fund (a) $ 17 $ 17 $ — $ — Other 9 9 2 2 Total $ 26 $ 26 $ 2 $ 2 (a) Funds received by WPD, which are to be spent on approved initiatives to support a low carbon environment.
Weighted-average Rates of Depreciation	Following are the weighted-average annual rates of depreciation, for regulated utility plant, for the years ended December 31: 2017 2016 2015 PPL 2.65 % 2.73 % 2.57 % PPL Electric 2.86 % 2.63 % 2.46 % LKE 3.64 % 3.69 % 3.69 % LG&E 3.63 % 3.58 % 3.65 % KU 3.66 % 3.77 % 3.71 %
Schedule of Utility Inventory	"Fuel, materials and supplies" on the Balance Sheets consisted of the following at December 31: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 Fuel $ 107 $ 158 $ 107 $ 158 $ 45 $ 60 $ 62 $ 98 Natural gas stored underground 43 42 43 42 43 42 — — Materials and supplies 170 156 104 97 43 41 61 56 Total $ 320 $ 356 $ 254 $ 297 $ 131 $ 143 $ 123 $ 154
PPL Electric Utilities Corp [Member]
Summary of Significant Accounting Policies [Line Items]
Schedule of Restricted Cash and Cash Equivalents	At December 31, the balances of restricted cash and cash equivalents included the following: PPL PPL Electric 2017 2016 2017 2016 Low carbon network fund (a) $ 17 $ 17 $ — $ — Other 9 9 2 2 Total $ 26 $ 26 $ 2 $ 2 (a) Funds received by WPD, which are to be spent on approved initiatives to support a low carbon environment.
Intercompany tax receivables (payables)	At December 31, the following intercompany tax receivables (payables) were recorded: 2017 2016 PPL Electric $ 61 $ 13 LKE (23 ) 1 LG&E — (18 ) KU — (29 )
LG And E And KU Energy LLC [Member]
Summary of Significant Accounting Policies [Line Items]
Intercompany tax receivables (payables)	At December 31, the following intercompany tax receivables (payables) were recorded: 2017 2016 PPL Electric $ 61 $ 13 LKE (23 ) 1 LG&E — (18 ) KU — (29 )
Schedule of Utility Inventory	"Fuel, materials and supplies" on the Balance Sheets consisted of the following at December 31: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 Fuel $ 107 $ 158 $ 107 $ 158 $ 45 $ 60 $ 62 $ 98 Natural gas stored underground 43 42 43 42 43 42 — — Materials and supplies 170 156 104 97 43 41 61 56 Total $ 320 $ 356 $ 254 $ 297 $ 131 $ 143 $ 123 $ 154
Louisville Gas And Electric Co [Member]
Summary of Significant Accounting Policies [Line Items]
Intercompany tax receivables (payables)	At December 31, the following intercompany tax receivables (payables) were recorded: 2017 2016 PPL Electric $ 61 $ 13 LKE (23 ) 1 LG&E — (18 ) KU — (29 )
Schedule of Utility Inventory	"Fuel, materials and supplies" on the Balance Sheets consisted of the following at December 31: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 Fuel $ 107 $ 158 $ 107 $ 158 $ 45 $ 60 $ 62 $ 98 Natural gas stored underground 43 42 43 42 43 42 — — Materials and supplies 170 156 104 97 43 41 61 56 Total $ 320 $ 356 $ 254 $ 297 $ 131 $ 143 $ 123 $ 154
Kentucky Utilities Co [Member]
Summary of Significant Accounting Policies [Line Items]
Intercompany tax receivables (payables)	At December 31, the following intercompany tax receivables (payables) were recorded: 2017 2016 PPL Electric $ 61 $ 13 LKE (23 ) 1 LG&E — (18 ) KU — (29 )
Schedule of Utility Inventory	"Fuel, materials and supplies" on the Balance Sheets consisted of the following at December 31: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 Fuel $ 107 $ 158 $ 107 $ 158 $ 45 $ 60 $ 62 $ 98 Natural gas stored underground 43 42 43 42 43 42 — — Materials and supplies 170 156 104 97 43 41 61 56 Total $ 320 $ 356 $ 254 $ 297 $ 131 $ 143 $ 123 $ 154

Segment and Related Informati37

Segment and Related Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment and Related Information	Income Statement data for the segments and reconciliation to PPL's consolidated results for the years ended December 31 are as follows: 2017 2016 2015 Operating Revenues from external customers (a) U.K. Regulated $ 2,091 $ 2,207 $ 2,410 Kentucky Regulated 3,156 3,141 3,115 Pennsylvania Regulated 2,195 2,156 2,124 Corporate and Other 5 13 20 Total $ 7,447 $ 7,517 $ 7,669 Depreciation U.K. Regulated $ 230 $ 233 $ 242 Kentucky Regulated 439 404 382 Pennsylvania Regulated 309 253 214 Corporate and Other 30 36 45 Total $ 1,008 $ 926 $ 883 Amortization (b) U.K. Regulated $ 34 $ 16 $ 6 Kentucky Regulated 24 29 27 Pennsylvania Regulated 33 32 26 Corporate and Other 6 3 — Total $ 97 $ 80 $ 59 Unrealized (gains) losses on derivatives and other hedging activities (c) U.K. Regulated $ 166 $ 13 $ (88 ) Kentucky Regulated 6 6 11 Corporate and Other 6 — — Total $ 178 $ 19 $ (77 ) Interest Expense U.K. Regulated $ 397 $ 402 $ 417 Kentucky Regulated 261 260 232 Pennsylvania Regulated 142 129 130 Corporate and Other 101 97 92 Total $ 901 $ 888 $ 871 Income from Continuing Operations Before Income Taxes U.K. Regulated $ 804 $ 1,479 $ 1,249 Kentucky Regulated 645 640 547 Pennsylvania Regulated 575 550 416 Corporate and Other (d) (112 ) (119 ) (144 ) Total $ 1,912 $ 2,550 $ 2,068 Income Taxes (e) U.K. Regulated $ 152 $ 233 $ 128 Kentucky Regulated 359 242 221 Pennsylvania Regulated 216 212 164 Corporate and Other (d) 57 (39 ) (48 ) Total $ 784 $ 648 $ 465 Deferred income taxes and investment tax credits (f) U.K. Regulated $ 66 $ 31 $ 45 Kentucky Regulated 294 291 236 Pennsylvania Regulated 257 221 220 Corporate and Other (d) 90 17 (73 ) Total $ 707 $ 560 $ 428 2017 2016 2015 Net Income U.K. Regulated $ 652 $ 1,246 $ 1,121 Kentucky Regulated 286 398 326 Pennsylvania Regulated 359 338 252 Corporate and Other (d) (169 ) (80 ) (96 ) Discontinued Operations (g) — — (921 ) Total $ 1,128 $ 1,902 $ 682 (a) See Note 1 for additional information on Operating Revenues. (b) Represents non-cash expense items that include amortization of regulatory assets, debt discounts and premiums, debt issuance costs, emission allowances and RECs. (c) Includes unrealized gains and losses from economic activity. See Note 17 for additional information. (d) 2015 includes certain costs related to the spinoff of PPL Energy Supply, including deferred income tax expense, transition costs and separation benefits for PPL Services employees. See Note 8 for additional information. (e) Represents both current and deferred income taxes, including investment tax credits. See Note 5 for additional information on the impact of the TCJA in 2017. (f) Represents a non-cash expense item that is also included in "Income Taxes." (g) 2015 includes an $879 million loss on the spinoff of PPL Energy Supply and five months of Supply segment earnings. See Note 8 for additional information on these transactions. Cash Flow data for the segments and reconciliation to PPL's consolidated results for the years ended December 31 are as follows: 2017 2016 2015 Expenditures for long-lived assets U.K. Regulated $ 1,015 $ 1,031 $ 1,242 Kentucky Regulated 892 791 1,210 Pennsylvania Regulated 1,254 1,134 1,107 Corporate and Other 10 1 11 Total $ 3,171 $ 2,957 $ 3,570 The following provides Balance Sheet data for the segments and reconciliation to PPL's consolidated results as of: As of December 31, 2017 2016 Total Assets U.K. Regulated (a) $ 16,813 $ 14,537 Kentucky Regulated 14,468 14,037 Pennsylvania Regulated 10,082 9,426 Corporate and Other (b) 116 315 Total $ 41,479 $ 38,315 (a) Includes $12.5 billion and $10.8 billion of net PP&E as of December 31, 2017 and December 31, 2016. WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. (b) Primarily consists of unallocated items, including cash, PP&E and the elimination of inter-segment transactions.
Geographic Data	Geographic data for the years ended December 31 are as follows: 2017 2016 2015 Revenues from external customers U.K. $ 2,091 $ 2,207 $ 2,410 U.S. 5,356 5,310 5,259 Total $ 7,447 $ 7,517 $ 7,669
Long-lived Assets	Geographic data for the years ended December 31 are as follows: As of December 31, 2017 2016 Long-Lived Assets U.K. $ 12,851 $ 11,177 U.S. 20,936 19,595 Total $ 33,787 $ 30,772

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Basic and Diluted EPS Computations	Reconciliations of the amounts of income and shares of PPL common stock (in thousands) for the periods ended December 31, used in the EPS calculation are: 2017 2016 2015 Income (Numerator) Income from continuing operations after income taxes $ 1,128 $ 1,902 $ 1,603 Less amounts allocated to participating securities 2 6 6 Income from continuing operations after income taxes available to PPL common shareowners - Basic and Diluted $ 1,126 $ 1,896 $ 1,597 Income (loss) from discontinued operations (net of income taxes) available to PPL common shareowners - Basic and Diluted $ — $ — $ (921 ) Net income $ 1,128 $ 1,902 $ 682 Less amounts allocated to participating securities 2 6 2 Net income available to PPL common shareowners - Basic and Diluted $ 1,126 $ 1,896 $ 680 2017 2016 2015 Shares of Common Stock (Denominator) Weighted-average shares - Basic EPS 685,240 677,592 669,814 Add incremental non-participating securities: Share-based payment awards (a) 2,094 2,854 2,772 Weighted-average shares - Diluted EPS 687,334 680,446 672,586 Basic EPS Available to PPL common shareowners: Income from continuing operations after income taxes $ 1.64 $ 2.80 $ 2.38 Income (loss) from discontinued operations (net of income taxes) — — (1.37 ) Net Income $ 1.64 $ 2.80 $ 1.01 Diluted EPS Available to PPL common shareowners: Income from continuing operations after income taxes $ 1.64 $ 2.79 $ 2.37 Income (loss) from discontinued operations (net of income taxes) — — (1.36 ) Net Income $ 1.64 $ 2.79 $ 1.01 (a) The Treasury Stock Method was applied to non-participating share-based payment awards.
Common Stock Issuances	For the year ended December 31, PPL issued common stock related to stock-based compensation plans and DRIP as follows (in thousands): 2017 Stock-based compensation plans (a) 1,748 DRIP 1,552 (a) Includes stock options exercised, vesting of performance units, vesting of restricted stock and restricted stock units and conversion of stock units granted to directors.
Antidilutive Securities Excluded From Diluted EPS	For the years ended December 31, the following shares (in thousands) were excluded from the computations of diluted EPS because the effect would have been antidilutive: 2017 2016 2015 Stock options 696 696 1,087 Performance units — 176 36

Income and Other Taxes (Tables)

Income and Other Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes [Line Items]
Tax Reform	The changes enacted by the TCJA were recorded as an adjustment to the Registrants' deferred tax provision, and have been reflected in "Income Taxes" on the Statement of Income for the year ended December 31, 2017 as follows: PPL PPL Electric LKE LG&E KU Income tax expense (benefit) $ 321 $ (13 ) $ 112 $ — $ — The rate reduction on non-regulated deferred tax assets and liabilities were recorded as an adjustment to the Registrants' deferred tax provision, and have been reflected in "Income Taxes" on the Statement of Income for the year ended December 31, 2017 as follows: PPL PPL Electric LKE LG&E KU Income tax expense (benefit) $ 220 $ (13 ) $ 112 $ — $ — The Balance Sheets at December 31, 2017 reflect the increase to the Registrants' net regulatory liabilities as a result of the TCJA as follows: PPL PPL Electric LKE LG&E KU Net Increase in Regulatory Liabilities $ 2,185 $ 1,019 $ 1,166 $ 532 $ 634
Components of Income (Loss) From Continuing Operations Before Income Taxes	"Income from Continuing Operations Before Income Taxes" included the following: 2017 2016 2015 Domestic income $ 874 $ 1,463 $ 968 Foreign income 1,038 1,087 1,100 Total $ 1,912 $ 2,550 $ 2,068
Components of Deferred Tax Assets and Liabilities	Significant components of PPL's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Deferred investment tax credits $ 33 $ 51 Regulatory liabilities 62 94 Income taxes due to customer (b) 499 — Accrued pension costs 159 250 Federal loss carryforwards 356 565 State loss carryforwards 409 326 Federal and state tax credit carryforwards 455 256 Foreign capital loss carryforwards 329 302 Foreign loss carryforwards 2 3 Foreign - pensions (32 ) 41 Foreign - regulatory obligations 2 6 Foreign - other 7 5 Contributions in aid of construction 134 141 Domestic - other 104 188 Unrealized losses on qualifying derivatives 10 20 Valuation allowances (838 ) (593 ) Total deferred tax assets 1,691 1,655 Deferred Tax Liabilities Domestic plant - net (b) 3,168 4,325 Taxes recoverable through future rates (b) — 170 Regulatory assets 211 343 Reacquired debt costs 15 25 Foreign plant - net 726 640 Domestic - other 9 14 Total deferred tax liabilities 4,129 5,517 Net deferred tax liability $ 2,438 $ 3,862 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal corporate income tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset.
Summary of Operating Loss Carryforwards and Tax Credit Carryforwards	At December 31, 2017 , PPL had the following loss and tax credit carryforwards, related deferred tax assets and valuation allowances recorded against the deferred tax assets. Gross Deferred Tax Asset Valuation Allowance Expiration Loss carryforwards Federal net operating losses (a) $ 1,662 $ 349 $ — 2029-2037 Federal charitable contributions (a) 36 7 — 2020-2022 State net operating losses (a) 5,512 407 (348 ) 2018-2037 State charitable contributions (a) 26 2 — 2018-2022 Foreign net operating losses 10 2 — Indefinite Foreign capital losses 1,938 329 (329 ) Indefinite Credit carryforwards Federal investment tax credit 133 — 2025-2036 Federal alternative minimum tax credit (b) 30 — Indefinite Federal foreign tax credits (c) 267 (148 ) 2024-2027 Federal - other 24 (8 ) 2019-2037 State - other 1 — Indefinite (a) Due to the enactment of the TCJA, deferred tax assets are reflected at the new U.S. federal corporate income tax rate of 21%. (b) The TCJA repealed the corporate alternative minimum tax (AMT) for tax years beginning after December 31, 2017. The existing indefinite carryforward period for AMT credits was retained. (c) Includes $62 million of foreign tax credits carried forward from 2016 and $205 million of additional foreign tax credits in 2017 related to the taxable deemed dividend associated with the TCJA.
Schedule of Valuation and Qualifying Accounts of Deferred Tax Assets	The changes in deferred tax valuation allowances were as follows: Additions Balance at Beginning of Period Charged to Income Charged to Other Accounts Deductions Balance at End of Period 2017 $ 593 $ 256 (a) $ — $ 11 $ 838 2016 662 17 2 88 (b) 593 2015 622 24 77 (c) 61 (b) 662 (a) Increase in valuation allowance of approximately $145 million related to expected future utilization of both 2017 foreign tax credits and pre-2017 foreign tax credits carried forward. For additional information, see the "Reconciliation of Income Tax Expense" and associated notes below. In addition, the reduction of the U.S. federal corporate income tax rate enacted by the TCJA in 2017 resulted in a $62 million increase in federal deferred tax assets and a corresponding valuation allowance related to the federal tax benefits of state net operating losses. (b) The reductions of the U.K. statutory income tax rates in 2016 and 2015 resulted in $19 million and $44 million in reductions in the deferred tax assets and corresponding valuation allowances. See "Reconciliation of Income Tax Expense" below for more information on the impact of the U.K. Finance Acts 2016 and 2015. In addition, the deferred tax assets and corresponding valuation allowances were reduced in 2016 by approximately $65 million due to the effect of foreign currency exchange rates. (c) Valuation allowance related to the deferred tax assets previously reflected on the PPL Energy Supply Segment. The deferred tax assets and related valuation allowance remained with PPL after the spinoff.
Components of Income Tax Expense (Benefit) From Continuing Operations	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows: 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ 6 $ (14 ) $ (26 ) Current - State 25 21 25 Current - Foreign 45 80 89 Total Current Expense 76 87 88 Deferred - Federal (a) 532 385 699 Deferred - State 88 89 68 Deferred - Foreign 133 86 41 Total Deferred Expense, excluding operating loss carryforwards 753 560 808 2017 2016 2015 Income Tax Expense (Benefit) Amortization of investment tax credit (3 ) (3 ) (4 ) Tax expense (benefit) of operating loss carryforwards Deferred - Federal (b) (16 ) 25 (396 ) Deferred - State (26 ) (21 ) (31 ) Total Tax Expense (Benefit) of Operating Loss Carryforwards (42 ) 4 (427 ) Total income taxes from continuing operations $ 784 $ 648 $ 465 Total income tax expense - Federal $ 519 $ 393 $ 273 Total income tax expense - State 87 89 62 Total income tax expense - Foreign 178 166 130 Total income taxes from continuing operations $ 784 $ 648 $ 465 (a) Due to the enactment of the TCJA in 2017, PPL recorded the following: • $220 million of deferred income tax expense related to the impact of the U.S. federal corporate income tax rate reduction from 35% to 21% on deferred tax assets and liabilities; • $162 million of deferred tax expense related to the utilization of current year losses resulting from the taxable deemed dividend; partially offset by, • $60 million of deferred tax benefits related to the $205 million of 2017 foreign tax credits partially offset by $145 million of valuation allowances. (b) Increase in federal loss carryforwards for 2015 primarily relates to the extension of bonus depreciation and the impact of bonus depreciation related to provision to return adjustments. In the table above, the following income tax expense (benefit) are excluded from income taxes from continuing operations: 2017 2016 2015 Discontinued operations - PPL Energy Supply Segment $ — $ — $ (30 ) Stock-based compensation recorded to Earnings Reinvested — (7 ) — Other comprehensive income (34 ) (6 ) (2 ) Valuation allowance on state deferred taxes recorded to other comprehensive income (1 ) 1 (4 ) Total $ (35 ) $ (12 ) $ (36 )
Reconciliation of Income Tax Expense Derived From Statutory Tax Rate	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows: 2017 2016 2015 Reconciliation of Income Tax Expense Federal income tax on Income from Continuing Operations Before Income Taxes at statutory tax rate - 35% $ 669 $ 893 $ 724 Increase (decrease) due to: State income taxes, net of federal income tax benefit 46 46 31 Valuation allowance adjustments (a) 36 16 24 Impact of lower U.K. income tax rates (b) (176 ) (177 ) (176 ) U.S. income tax on foreign earnings - net of foreign tax credit (c) 47 (42 ) 8 Federal and state tax reserves adjustments (d) — — (22 ) Foreign income return adjustments (8 ) 2 — Impact of the U.K. Finance Acts on deferred tax balances (b) (16 ) (49 ) (91 ) Depreciation not normalized (10 ) (10 ) (5 ) Interest benefit on U.K. financing entities (16 ) (17 ) (20 ) Stock-based compensation (e) (3 ) (10 ) — Deferred tax impact of U.S. tax reform (f) 220 — — Other (5 ) (4 ) (8 ) Total increase (decrease) 115 (245 ) (259 ) Total income taxes from continuing operations $ 784 $ 648 $ 465 Effective income tax rate 41.0 % 25.4 % 22.5 % (a) During 2017, PPL recorded an increase in valuation allowances of $23 million primarily related to foreign tax credits recorded in 2016. The future utilization of these credits is expected to be lower as a result of the TCJA. During 2017 and 2016, PPL recorded deferred income tax expense of $16 million and $13 million for valuation allowances primarily related to increased Pennsylvania net operating loss carryforwards expected to be unutilized. During 2015, PPL recorded $24 million of deferred income tax expense related to deferred tax valuation allowances. PPL recorded state deferred income tax expense of $12 million primarily related to increased Pennsylvania net operating loss carryforwards expected to be unutilized and $12 million of federal deferred income tax expense primarily related to federal tax credit carryforwards that are expected to expire as a result of lower future taxable earnings due to the extension of bonus depreciation. (b) The U.K. Finance Act 2016, enacted in September 2016, reduced the U.K. statutory income tax rate effective April 1, 2020 from 18% to 17%. As a result, PPL reduced its net deferred tax liabilities and recognized a $42 million deferred income tax benefit during 2016. The U.K. Finance Act 2015, enacted in November 2015, reduced the U.K. statutory income tax rate from 20% to 19% effective April 1, 2017 and from 19% to 18% effective April 1, 2020. As a result, PPL reduced its net deferred tax liabilities and recognized a $90 million deferred income tax benefit during 2015, related to both rate decreases. (c) During 2017, PPL recorded a federal income tax benefit of $35 million primarily attributable to U.K. pension contributions. During 2017, PPL recorded deferred income tax expense of $83 million primarily related to enactment of the TCJA. The enacted tax law included a conversion from a worldwide tax system to a territorial tax system, effective January 1, 2018. In the transition to the territorial regime, a one-time transition tax was imposed on PPL’s unrepatriated accumulated foreign earnings in 2017. These earnings were treated as a taxable deemed dividend to PPL of approximately $462 million , including $205 million of foreign tax credits. As the PPL consolidated U.S. group had a taxable loss for 2017, inclusive of the taxable deemed dividend, these credits were recorded as a deferred tax asset. However, it is expected that under the TCJA, only $83 million of the $205 million of foreign tax credits will be realized in the carry forward period. Accordingly, a valuation allowance on the current year foreign tax credits in the amount of $122 million has been recorded to reflect the reduction in the future utilization of the credits. The foreign tax credits associated with the deemed repatriation result in a gross carryforward and corresponding deferred tax asset of $205 million offset by a valuation allowance of $122 million . During 2016, PPL recorded lower income taxes primarily attributable to foreign tax credit carryforwards, arising from a decision to amend prior year tax returns to claim foreign tax credits rather than deduct foreign taxes. This decision was prompted by changes to the Company's most recent business plan. (d) During 2015, PPL recorded a $9 million income tax benefit related to a planned amendment of a prior period tax return and a $12 million income tax benefit related to the settlement of the IRS audit for the tax years 1998-2011. (e) During 2016, PPL recorded lower income tax expense related to the application of new stock-based compensation accounting guidance. See Note 1 for additional information. (f) During 2017, PPL recorded deferred income tax expense related to the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA.
Details of Taxes Other Than Income	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows: 2017 2015 2015 Taxes, other than income State gross receipts (a) $ 102 $ 100 $ 89 State capital stock (6 ) — — Foreign property 127 135 148 Domestic Other 69 66 62 Total $ 292 $ 301 $ 299 (a) In 2015, the settlement of a 2011 gross receipts tax audit resulted in the reversal of $17 million of previously recognized reserves.
Summary of Income Tax Examinations	With few exceptions, at December 31, 2017 , these jurisdictions, as well as the tax years that are no longer subject to examination, were as follows. PPL PPL Electric LKE LG&E KU U.S. (federal) 2013 and prior 2013 and prior 2013 and prior 2013 and prior 2013 and prior Pennsylvania (state) 2011 and prior 2011 and prior Kentucky (state) 2012 and prior 2012 and prior 2012 and prior 2012 and prior U.K. (foreign) 2014 and prior
PPL Electric Utilities Corp [Member]
Income Taxes [Line Items]
Components of Deferred Tax Assets and Liabilities	Significant components of PPL Electric's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Accrued pension costs $ 63 $ 107 Contributions in aid of construction 117 112 Regulatory liabilities 25 34 Income taxes due to customers (b) 193 — State loss carryforwards 19 22 Federal loss carryforwards 91 147 Other 45 81 Total deferred tax assets 553 503 Deferred Tax Liabilities Electric utility plant - net (b) 1,544 2,001 Taxes recoverable through future rates (b) — 141 Reacquired debt costs 8 15 Regulatory assets 150 240 Other 5 5 Total deferred tax liabilities 1,707 2,402 Net deferred tax liability $ 1,154 $ 1,899 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset.
Summary of Operating Loss Carryforwards and Tax Credit Carryforwards	At December 31, 2017 , PPL Electric had the following loss carryforwards and related deferred tax assets: Gross Deferred Tax Asset Expiration Loss carryforwards (a) Federal net operating losses $ 426 $ 89 2031-2037 Federal charitable contributions 8 2 2020-2022 State net operating losses 233 18 2030-2032 State charitable contributions 13 1 2018-2022 (a) Due to the enactment of the TCJA, deferred tax assets are reflected at the new U.S. federal corporate income tax rate of 21%.
Components of Income Tax Expense (Benefit) From Continuing Operations	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows. 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ (65 ) $ (29 ) $ (80 ) Current - State 20 19 23 Total Current Expense (Benefit) (45 ) (10 ) (57 ) Deferred - Federal (a) 234 193 287 Deferred - State 29 29 12 Total Deferred Expense, excluding operating loss carryforwards 263 222 299 2017 2016 2015 Amortization of investment tax credit — — — Tax expense (benefit) of operating loss carryforwards Deferred - Federal (5 ) — (75 ) Deferred - State — — (3 ) Total Tax Expense (Benefit) of Operating Loss Carryforwards (5 ) — (78 ) Total income tax expense $ 213 $ 212 $ 164 Total income tax expense - Federal $ 164 $ 164 $ 132 Total income tax expense - State 49 48 32 Total income tax expense $ 213 $ 212 $ 164 (a) Due to the enactment of the TCJA in 2017, PPL Electric recorded a $13 million deferred tax benefit related to the impact of the U.S. federal corporate income tax rate reduction from 35% to 21% on deferred tax assets and liabilities.
Reconciliation of Income Tax Expense Derived From Statutory Tax Rate	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows. 2017 2016 2015 Reconciliation of Income Taxes Federal income tax on Income Before Income Taxes at statutory tax rate - 35% $ 201 $ 193 $ 146 Increase (decrease) due to: State income taxes, net of federal income tax benefit 36 36 25 Depreciation not normalized (8 ) (8 ) (4 ) Stock-based compensation (a) (2 ) (6 ) — Deferred tax impact of U.S. tax reform (b) (13 ) — — Other (1 ) (3 ) (3 ) Total increase (decrease) 12 19 18 Total income tax expense $ 213 $ 212 $ 164 Effective income tax rate 37.0 % 38.4 % 39.4 % (a) During 2016, PPL Electric recorded lower income tax expense related to the application of new stock-based compensation accounting guidance. See Note 1 for additional information. (b) During 2017, PPL Electric recorded a deferred tax benefit related to the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA.
Details of Taxes Other Than Income	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were as follows. 2017 2016 2015 Taxes, other than income State gross receipts (a) $ 102 $ 100 $ 89 Property and other 5 5 5 Total $ 107 $ 105 $ 94 (a) In 2015, the settlement of a 2011 gross receipts tax audit resulted in the reversal of $17 million of previously recognized reserves.
LG And E And KU Energy LLC [Member]
Income Taxes [Line Items]
Components of Deferred Tax Assets and Liabilities	Significant components of LKE's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Federal loss carryforwards $ 150 $ 248 State loss carryforwards 41 35 Federal tax credit carryforwards 181 186 Contributions in aid of construction 17 29 Regulatory liabilities 37 60 Accrued pension costs 29 58 Income taxes due to customers (b) 305 15 Deferred investment tax credits 33 51 Derivative liability 7 12 Other 26 49 Valuation allowances (8 ) (11 ) Total deferred tax assets 818 732 Deferred Tax Liabilities Plant - net (b) 1,615 2,352 Regulatory assets 61 102 Other 8 13 Total deferred tax liabilities 1,684 2,467 Net deferred tax liability $ 866 $ 1,735 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset.
Summary of Operating Loss Carryforwards and Tax Credit Carryforwards	At December 31, 2017 , LKE had the following loss and tax credit carryforwards, related deferred tax assets, and valuation allowances recorded against the deferred tax assets. Gross Deferred Tax Asset Valuation Allowance Expiration Loss carryforwards (a) Federal net operating losses $ 713 $ 150 $ — 2028-2037 Federal charitable contributions 14 3 — 2020-2022 State net operating losses 874 41 — 2028-2037 Credit carryforwards Federal investment tax credit 133 — 2025-2036 Federal alternative minimum tax credit (b) 27 — Indefinite Federal - other 21 (8 ) 2019-2037 State - other 1 — Indefinite (a) Due to the enactment of the TCJA, deferred tax assets are reflected at the new U.S. federal corporate income tax rate of 21%. (b) The TCJA repealed the corporate alternative minimum tax (AMT) for tax years beginning after December 31, 2017. The existing indefinite carryforward period for AMT credits was retained.
Schedule of Valuation and Qualifying Accounts of Deferred Tax Assets	Changes in deferred tax valuation allowances were: Balance at Beginning of Period Additions Deductions Balance at End of Period 2017 $ 11 $ 4 (a) $ 7 (b) $ 8 2016 12 — 1 (b) 11 2015 — 12 (c) — 12 (a) Federal tax credits expiring in 2021 that are more likely than not to expire before being utilized. (b) Federal tax credit expiring. (c) Federal tax credits expiring in 2016 through 2020 that are more likely than not to expire before being utilized.
Components of Income Tax Expense (Benefit) From Continuing Operations	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ 74 $ (36 ) $ 2 Current - State 6 1 1 Total Current Expense (Benefit) 80 (35 ) 3 Deferred - Federal (a) 268 248 405 Deferred - State 32 38 32 Total Deferred Expense, excluding benefits of operating loss carryforwards 300 286 437 Amortization of investment tax credit - Federal (3 ) (3 ) (3 ) Tax benefit of operating loss carryforwards Deferred - Federal (2 ) 10 (198 ) Deferred - State — (1 ) — Total Tax Expense (Benefit) of Operating Loss Carryforwards (2 ) 9 (198 ) Total income tax expense from continuing operations (b) $ 375 $ 257 $ 239 Total income tax expense - Federal $ 337 $ 219 $ 206 Total income tax expense - State 38 38 33 Total income tax expense from continuing operations (b) $ 375 $ 257 $ 239 (a) Due to the enactment of the TCJA in 2017, LKE recorded $112 million of deferred income tax expense, of which $108 million related to the impact of the U.S. federal corporate income tax rate reduction from 35% to 21% on deferred tax assets and liabilities and $4 million related to valuation allowances on tax credits expiring in 2021. (b) Excludes deferred federal and state tax expense (benefit) recorded to OCI of $(10) million in 2017 , $(16) million in 2016 and less than $(1) million in 2015 .
Reconciliation of Income Tax Expense Derived From Statutory Tax Rate	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Reconciliation of Income Taxes Federal income tax on Income Before Income Taxes at statutory tax rate - 35% $ 242 $ 240 $ 211 Increase (decrease) due to: State income taxes, net of federal income tax benefit 25 25 22 Amortization of investment tax credit (3 ) (3 ) (3 ) Valuation allowance adjustment (a) — — 12 Stock-based compensation (b) 1 (3 ) — Deferred tax impact of U.S. tax reform (c) 112 — — Other (2 ) (2 ) (3 ) Total increase 133 17 28 Total income tax expense $ 375 $ 257 $ 239 Effective income tax rate 54.3 % 37.5 % 39.6 % (a) Represents a valuation allowance against tax credits expiring through 2020 that are more likely than not to expire before being utilized. (b) During 2016, LKE recorded lower income tax expense related to the application of new stock-based compensation accounting guidance. See Note 1 for additional information. (c) During 2017, LKE recorded deferred income tax expense primarily due to the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA.
Details of Taxes Other Than Income	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income from Continuing Operations Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Taxes, other than income Property and other $ 65 $ 62 $ 57 Total $ 65 $ 62 $ 57
Louisville Gas And Electric Co [Member]
Income Taxes [Line Items]
Components of Deferred Tax Assets and Liabilities	Significant components of LG&E's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Federal loss carryforwards $ 29 $ 80 Contributions in aid of construction 11 18 Regulatory liabilities 21 34 Deferred investment tax credits 9 14 Income taxes due to customers (b) 142 17 Derivative liability 7 12 Other 12 17 Total deferred tax assets 231 192 Deferred Tax Liabilities Plant - net (b) 724 1,058 Regulatory assets 40 65 Accrued pension costs 34 35 Other 5 8 Total deferred tax liabilities 803 1,166 Net deferred tax liability $ 572 $ 974 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset.
Components of Income Tax Expense (Benefit) From Continuing Operations	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ — $ (22 ) $ (15 ) Current - State 5 1 3 Total current Expense (Benefit) 5 (21 ) (12 ) Deferred - Federal 112 134 190 Deferred - State 14 18 13 Total Deferred Expense, excluding benefits of operating loss carryforwards 126 152 203 Amortization of investment tax credit - Federal (1 ) (1 ) (1 ) Tax benefit of operating loss carryforwards Deferred - Federal 1 (4 ) (76 ) Total Tax Benefit of Operating Loss Carryforwards 1 (4 ) (76 ) Total income tax expense $ 131 $ 126 $ 114 Total income tax expense - Federal $ 112 $ 107 $ 98 Total income tax expense - State 19 19 16 Total income tax expense $ 131 $ 126 $ 114
Reconciliation of Income Tax Expense Derived From Statutory Tax Rate	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Reconciliation of Income Taxes Federal income tax on Income Before Income Taxes at statutory tax rate - 35% $ 120 $ 115 $ 105 Increase (decrease) due to: State income taxes, net of federal income tax benefit 13 12 11 Amortization of investment tax credit (1 ) (1 ) (1 ) Other (1 ) — (1 ) Total increase 11 11 9 Total income tax expense $ 131 $ 126 $ 114 Effective income tax rate 38.1 % 38.3 % 38.1 %
Details of Taxes Other Than Income	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Taxes, other than income Property and other $ 33 $ 32 $ 28 Total $ 33 $ 32 $ 28
Kentucky Utilities Co [Member]
Income Taxes [Line Items]
Components of Deferred Tax Assets and Liabilities	Significant components of KU's deferred income tax assets and liabilities were as follows: 2017 (a) 2016 Deferred Tax Assets Federal loss carryforwards $ 13 $ 79 Contributions in aid of construction 6 11 Regulatory liabilities 16 26 Deferred investment tax credits 24 37 Income taxes due to customers (b) 163 — Other 9 11 Total deferred tax assets 231 164 Deferred Tax Liabilities Plant - net (b) 882 1,280 Regulatory assets 21 37 Accrued pension costs 17 12 Other 2 5 Total deferred tax liabilities 922 1,334 Net deferred tax liability $ 691 $ 1,170 (a) Deferred tax assets and liabilities at December 31, 2017 reflect the U.S. federal corporate income tax rate reduction from 35% to 21% enacted by the TCJA. (b) The impact on net deferred tax liabilities as a result of the U.S. federal tax rate reduction enacted by the TCJA is primarily related to plant (net of net operating losses) and resulted in a regulatory liability for income taxes due to customers, the deferred tax impact of which is reflected as a deferred tax asset.
Components of Income Tax Expense (Benefit) From Continuing Operations	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Income Tax Expense (Benefit) Current - Federal $ — $ 31 $ (21 ) Current - State 7 5 1 Total Current Expense (Benefit) 7 36 (20 ) Deferred - Federal 138 131 240 Deferred - State 16 19 19 Total Deferred Expense, excluding benefits of operating loss carryforwards 154 150 259 Amortization of investment tax credit - Federal (2 ) (2 ) (2 ) Tax benefit of operating loss carryforwards Deferred - Federal — (21 ) (97 ) Total Tax Benefit of Operating Loss Carryforwards — (21 ) (97 ) Total income tax expense (a) $ 159 $ 163 $ 140 Total income tax expense - Federal $ 136 $ 139 $ 120 Total income tax expense - State 23 24 20 Total income tax expense (a) $ 159 $ 163 $ 140 (a) Excludes deferred federal and state tax expense (benefit) recorded to OCI of less than $1 million in 2017 , and less than $(1) million in 2016 and 2015 .
Reconciliation of Income Tax Expense Derived From Statutory Tax Rate	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Reconciliation of Income Taxes Federal income tax on Income Before Income Taxes at statutory tax rate - 35% $ 146 $ 150 $ 131 Increase (decrease) due to: State income taxes, net of federal income tax benefit 15 16 13 Amortization of investment tax credit (2 ) (2 ) (2 ) Other — (1 ) (2 ) Total increase 13 13 9 Total income tax expense $ 159 $ 163 $ 140 Effective income tax rate 38.0 % 38.1 % 37.4 %
Details of Taxes Other Than Income	Details of the components of income tax expense, a reconciliation of federal income taxes derived from statutory tax rates applied to "Income Before Income Taxes" to income taxes for reporting purposes, and details of "Taxes, other than income" were: 2017 2016 2015 Taxes, other than income Property and other $ 32 $ 30 $ 29 Total $ 32 $ 30 $ 29

Utility Rate Regulation (Tables

Utility Rate Regulation (Tables)	12 Months Ended
	Dec. 31, 2017
Regulated Operations [Line Items]
Regulatory Assets and Liabilities	The following table provides information about the regulatory assets and liabilities of cost-based rate-regulated utility operations at December 31, : PPL PPL Electric 2017 2016 2017 2016 Current Regulatory Assets: Environmental cost recovery $ 5 $ 6 $ — $ — Generation formula rate 6 11 — — Transmission service charge — 7 — 7 Gas supply clause 4 3 — — Smart meter rider 15 6 15 6 Storm costs — 5 — 5 Other 4 1 1 1 Total current regulatory assets (a) $ 34 $ 39 $ 16 $ 19 Noncurrent Regulatory Assets: Defined benefit plans $ 880 $ 947 $ 504 $ 549 Taxes recoverable through future rates 3 340 3 340 Storm costs 33 57 — 9 Unamortized loss on debt 54 61 29 36 Interest rate swaps 26 31 — — Terminated interest rate swaps 92 98 — — Accumulated cost of removal of utility plant 173 159 173 159 AROs 234 211 — — Other 9 14 — 1 Total noncurrent regulatory assets $ 1,504 $ 1,918 $ 709 $ 1,094 Current Regulatory Liabilities: Generation supply charge $ 34 $ 23 $ 34 $ 23 Transmission service charge 9 — 9 — Universal service rider 26 14 26 14 Transmission formula rate 9 15 9 15 Fuel adjustment clauses 3 11 — — Act 129 compliance rider — 17 — 17 Storm damage expense rider 8 13 8 13 Other 6 8 — 1 Total current regulatory liabilities $ 95 $ 101 $ 86 $ 83 Noncurrent Regulatory Liabilities: Accumulated cost of removal of utility plant $ 677 $ 700 $ — $ — Power purchase agreement - OVEC (b) 68 75 — — Net deferred taxes (c) 1,853 23 668 — Defined benefit plans 27 23 — — Terminated interest rate swaps 74 78 — — Other 5 — — — Total noncurrent regulatory liabilities $ 2,704 $ 899 $ 668 $ — LKE LG&E KU 2017 2016 2017 2016 2017 2016 Current Regulatory Assets: Environmental cost recovery $ 5 $ 6 $ 5 $ 6 $ — $ — Generation formula rate 6 11 — — 6 11 Gas supply clause 4 3 4 3 — — Other 3 — 3 — — — Total current regulatory assets $ 18 $ 20 $ 12 $ 9 $ 6 $ 11 LKE LG&E KU 2017 2016 2017 2016 2017 2016 Noncurrent Regulatory Assets: Defined benefit plans $ 376 $ 398 $ 234 $ 246 $ 142 $ 152 Storm costs 33 48 18 26 15 22 Unamortized loss on debt 25 25 16 16 9 9 Interest rate swaps 26 31 26 31 — — Terminated interest rate swaps 92 98 54 57 38 41 AROs 234 211 61 70 173 141 Other 9 13 2 4 7 9 Total noncurrent regulatory assets $ 795 $ 824 $ 411 $ 450 $ 384 $ 374 Current Regulatory Liabilities: Demand side management $ — $ 3 $ — $ 2 $ — $ 1 Fuel adjustment clause 3 11 — 2 3 9 Gas line tracker 3 — 3 — — — Other 3 4 — 1 3 3 Total current regulatory liabilities $ 9 $ 18 $ 3 $ 5 $ 6 $ 13 Noncurrent Regulatory Liabilities: Accumulated cost of removal of utility plant $ 677 $ 700 $ 282 $ 305 $ 395 $ 395 Power purchase agreement - OVEC (b) 68 75 47 52 21 23 Net deferred taxes (c) 1,185 23 552 23 633 — Defined benefit plans 27 23 — — 27 23 Terminated interest rate swaps 74 78 37 39 37 39 Other 5 — 1 — 4 — Total noncurrent regulatory liabilities $ 2,036 $ 899 $ 919 $ 419 $ 1,117 $ 480 (a) For PPL, these amounts are included in "Other current assets" on the Balance Sheets. (b) This liability was recorded as an offset to an intangible asset that was recorded at fair value upon the acquisition of LKE by PPL. (c) Primarily relates to excess deferred taxes recorded as a result of the TCJA, which lowered the federal corporate income tax rate effective January 1, 2018 requiring deferred tax balances and the associated regulatory liabilities to be remeasured as of December 31, 2017.

Financing Activities (Tables)

Financing Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Line Items]
Credit Facilities in Place at Period End	The following credit facilities were in place at: December 31, 2017 December 31, 2016 Expiration Date Capacity Borrowed Letters of Credit and Commercial Paper Issued Unused Capacity Borrowed Letters of Credit and Commercial Paper Issued PPL U.K. WPD plc Syndicated Credit Facility (a) (c) Jan. 2022 £ 210 £ 148 £ — £ 60 £ 160 £ — WPD (South West) Syndicated Credit Facility (a) (c) July 2021 245 — — 245 110 — WPD (East Midlands) Syndicated Credit Facility (a) (c) July 2021 300 180 — 120 9 — WPD (West Midlands) Syndicated Credit Facility (a) (c) July 2021 300 120 — 180 — — Uncommitted Credit Facilities 100 — 4 96 60 4 Total U.K. Credit Facilities (b) £ 1,155 £ 448 £ 4 £ 701 £ 339 £ 4 U.S. PPL Capital Funding Syndicated Credit Facility (c) (d) Jan. 2022 $ 950 $ — $ 230 $ 720 $ — $ 20 Syndicated Credit Facility (c) (d) Nov. 2018 300 — — 300 — — Bilateral Credit Facility (c) (d) Mar. 2018 150 — 18 132 — 17 Total PPL Capital Funding Credit Facilities $ 1,400 $ — $ 248 $ 1,152 $ — $ 37 PPL Electric Syndicated Credit Facility (c) (d) Jan. 2022 $ 650 $ — $ 1 $ 649 $ — $ 296 LKE Syndicated Credit Facility (c) (d) Oct. 2018 $ 75 $ — $ — $ 75 $ — $ — LG&E Syndicated Credit Facility (c) (d) Jan. 2022 $ 500 $ — $ 199 $ 301 $ — $ 169 Term Loan Credit Facility (c) (e) Oct. 2019 200 100 — 100 — — Total LG&E Credit Facilities $ 700 $ 100 $ 199 $ 401 $ — $ 169 KU Syndicated Credit Facility (c) (d) Jan. 2022 $ 400 $ — $ 45 $ 355 $ — $ 16 Letter of Credit Facility (c) (d) (f) Oct. 2020 198 — 198 — — 198 Total KU Credit Facilities $ 598 $ — $ 243 $ 355 $ — $ 214 (a) The facilities contain financial covenants to maintain an interest coverage ratio of not less than 3.0 times consolidated earnings before income taxes, depreciation and amortization and total net debt not in excess of 85% of its RAV, calculated in accordance with the credit facility. (b) The WPD plc amounts borrowed at December 31, 2017 and 2016 included USD-denominated borrowings of $200 million for both periods, which bore interest at 2.17% and 1.43% . The unused capacity reflects the amount borrowed in GBP of £150 million as of the date borrowed. The WPD (East Midlands) amount borrowed at December 31, 2017 was a GBP-denominated borrowing, which equated to $244 million and bore interest at 0.89% . The WPD (West Midlands) amount borrowed at December 31, 2017 was a GBP-denominated borrowing, which equated to $162 million and bore interest at 0.89% . At December 31, 2017 , the unused capacity under the U.K. credit facilities was approximately $949 million . (c) Each company pays customary fees under its respective facility and borrowings generally bear interest at LIBOR-based rates plus an applicable margin. (d) The facilities contain a financial covenant requiring debt to total capitalization not to exceed 70% for PPL Capital Funding, PPL Electric, LKE, LG&E and KU, as calculated in accordance with the facilities and other customary covenants. Additionally, as it relates to the syndicated and bilateral credit facilities and subject to certain conditions, PPL Capital Funding may request that the capacity of its facilities expiring in November 2018 and March 2018 be increased by up to $30 million , LG&E and KU each may request up to a $100 million increase in its facility's capacity and LKE may request up to a $25 million increase in its facility's capacity. (e) LG&E entered into a term loan credit agreement in October 2017 whereby it may borrow up to $200 million . The outstanding borrowings at December 31, 2017 bore interest at a rate of 2.06% . (f) KU's letter of credit facility agreement allows for certain payments under the letter of credit facility to be converted to loans rather than requiring immediate payment.
Commercial paper	The following commercial paper programs were in place at: December 31, 2017 December 31, 2016 Weighted - Capacity Commercial Unused Weighted - Commercial PPL Capital Funding 1.64% $ 1,000 $ 230 $ 770 1.10% $ 20 PPL Electric 650 — 650 1.05% 295 LG&E 1.83% 350 199 151 0.94% 169 KU 1.97% 350 45 305 0.87% 16 Total $ 2,350 $ 474 $ 1,876 $ 500
Long-term Debt	Long-term Debt (All Registrants) December 31, Weighted-Average Maturities (g) 2017 2016 PPL U.S. Senior Unsecured Notes 3.78 % 2020 - 2047 $ 4,575 $ 4,075 Senior Secured Notes/First Mortgage Bonds (a) (b) (c) 3.96 % 2018 - 2047 7,314 6,849 Junior Subordinated Notes 5.10 % 2067 - 2073 930 930 Term Loan Credit Facility 2.06 % 2019 100 — Total U.S. Long-term Debt 12,919 11,854 U.K. Senior Unsecured Notes (d) 5.24 % 2020 - 2040 6,351 5,707 Index-linked Senior Unsecured Notes (e) 1.56 % 2026 - 2056 1,012 838 Total U.K. Long-term Debt (f) 7,363 6,545 Total Long-term Debt Before Adjustments 20,282 18,399 Fair market value adjustments 21 22 Unamortized premium and (discount), net (e) 14 20 Unamortized debt issuance costs (122 ) (115 ) Total Long-term Debt 20,195 18,326 Less current portion of Long-term Debt 348 518 Total Long-term Debt, noncurrent $ 19,847 $ 17,808 December 31, Weighted-Average Maturities (g) 2017 2016 PPL Electric Senior Secured Notes/First Mortgage Bonds (a) (b) 4.23 % 2020 - 2047 $ 3,339 $ 2,864 Total Long-term Debt Before Adjustments 3,339 2,864 Unamortized discount (16 ) (12 ) Unamortized debt issuance costs (25 ) (21 ) Total Long-term Debt 3,298 2,831 Less current portion of Long-term Debt — 224 Total Long-term Debt, noncurrent $ 3,298 $ 2,607 LKE Senior Unsecured Notes 3.97 % 2020 - 2021 $ 725 $ 725 Term Loan Credit Facility 2.06 % 2019 100 — First Mortgage Bonds (a) (c) 3.73 % 2018 - 2045 3,975 3,985 Long-term debt to affiliate 3.50 % 2026 400 400 Total Long-term Debt Before Adjustments 5,200 5,110 Fair market value adjustments — (1 ) Unamortized discount (14 ) (15 ) Unamortized debt issuance costs (27 ) (29 ) Total Long-term Debt 5,159 5,065 Less current portion of Long-term Debt 98 194 Total Long-term Debt, noncurrent $ 5,061 $ 4,871 LG&E Term Loan Credit Facility 2.06 % 2019 $ 100 $ — First Mortgage Bonds (a) (c) 3.48 % 2018 - 2045 1,624 1,634 Total Long-term Debt Before Adjustments 1,724 1,634 Fair market value adjustments — (1 ) Unamortized discount (4 ) (4 ) Unamortized debt issuance costs (11 ) (12 ) Total Long-term Debt 1,709 1,617 Less current portion of Long-term Debt 98 194 Total Long-term Debt, noncurrent $ 1,611 $ 1,423 KU First Mortgage Bonds (a) (c) 3.91 % 2019 - 2045 $ 2,351 $ 2,351 Total Long-term Debt Before Adjustments 2,351 2,351 Unamortized discount (9 ) (9 ) Unamortized debt issuance costs (14 ) (15 ) Total Long-term Debt 2,328 2,327 Less current portion of Long-term Debt — — Total Long-term Debt, noncurrent $ 2,328 $ 2,327 (a) Includes PPL Electric's senior secured and first mortgage bonds that are secured by the lien of PPL Electric's 2001 Mortgage Indenture, which covers substantially all electric distribution plant and certain transmission plant owned by PPL Electric. The carrying value of PPL Electric's property, plant and equipment was approximately $8.5 billion and $7.6 billion at December 31, 2017 and 2016 . Includes LG&E's first mortgage bonds that are secured by the lien of the LG&E 2010 Mortgage Indenture which creates a lien, subject to certain exceptions and exclusions, on substantially all of LG&E's real and tangible personal property located in Kentucky and used or to be used in connection with the generation, transmission and distribution of electricity and the storage and distribution of natural gas. The aggregate carrying value of the property subject to the lien was $4.7 billion and $4.4 billion at December 31, 2017 and 2016 . Includes KU's first mortgage bonds that are secured by the lien of the KU 2010 Mortgage Indenture which creates a lien, subject to certain exceptions and exclusions, on substantially all of KU's real and tangible personal property located in Kentucky and used or to be used in connection with the generation, transmission and distribution of electricity. The aggregate carrying value of the property subject to the lien was $6.0 billion and $5.8 billion at December 31, 2017 and 2016 . (b) Includes PPL Electric's series of senior secured bonds that secure its obligations to make payments with respect to each series of Pollution Control Bonds that were issued by the LCIDA and the PEDFA on behalf of PPL Electric. These senior secured bonds were issued in the same principal amount, contain payment and redemption provisions that correspond to and bear the same interest rate as such Pollution Control Bonds. These senior secured bonds were issued under PPL Electric's 2001 Mortgage Indenture and are secured as noted in (a) above. This amount includes $224 million of which PPL Electric is allowed to convert the interest rate mode on the bonds from time to time to a commercial paper rate, daily rate, weekly rate, or term rate of at least one year and $90 million that may be redeemed, in whole or in part, at par beginning in October 2020 , and are subject to mandatory redemption upon determination that the interest rate on the bonds would be included in the holders' gross income for federal tax purposes. (c) Includes LG&E's and KU's series of first mortgage bonds that were issued to the respective trustees of tax-exempt revenue bonds to secure its respective obligations to make payments with respect to each series of bonds. The first mortgage bonds were issued in the same principal amounts, contain payment and redemption provisions that correspond to and bear the same interest rate as such tax-exempt revenue bonds. These first mortgage bonds were issued under the LG&E 2010 Mortgage Indenture and the KU 2010 Mortgage Indenture and are secured as noted in (a) above. The related tax-exempt revenue bonds were issued by various governmental entities, principally counties in Kentucky, on behalf of LG&E and KU. The related revenue bond documents allow LG&E and KU to convert the interest rate mode on the bonds from time to time to a commercial paper rate, daily rate, weekly rate, term rate of at least one year or, in some cases, an auction rate or a LIBOR index rate. At December 31, 2017 , the aggregate tax-exempt revenue bonds issued on behalf of LG&E and KU that were in a term rate mode totaled $514 million for LKE, comprised of $391 million and $123 million for LG&E and KU. At December 31, 2017 , the aggregate tax-exempt revenue bonds issued on behalf of LG&E and KU that were in a variable rate mode totaled $375 million for LKE, comprised of $147 million and $228 million for LG&E and KU. These variable rate tax-exempt revenue bonds are subject to tender for purchase by LG&E and KU at the option of the holder and to mandatory tender for purchase by LG&E and KU upon the occurrence of certain events. (d) Includes £225 million ( $304 million at December 31, 2017 ) of notes that may be redeemed, in total but not in part, on December 21, 2026 , at the greater of the principal value or a value determined by reference to the gross redemption yield on a nominated U.K. Government bond. (e) The principal amount of the notes issued by WPD (South West), WPD (East Midlands) and WPD (South Wales) is adjusted based on changes in a specified index, as detailed in the terms of the related indentures. The adjustment to the principal amounts from 2016 to 2017 was an increase of approximately £27 million ( $37 million ) resulting from inflation. In addition, this amount includes £225 million ( $304 million at December 31, 2017 ) of notes issued by WPD (South West) that may be redeemed, in total by series, on December 1, 2026 , at the greater of the adjusted principal value and a make-whole value determined by reference to the gross real yield on a nominated U.K. government bond. (f) Includes £4.7 billion ( $6.4 billion at December 31, 2017 ) of notes that may be put by the holders to the issuer for redemption if the long-term credit ratings assigned to the notes are withdrawn by any of the rating agencies (Moody's or S&P) or reduced to a non-investment grade rating of Ba1 or BB+ or lower in connection with a restructuring event, which includes the loss of, or a material adverse change to, the distribution licenses under which the issuer operates. (g) The table reflects principal maturities only, based on stated maturities or earlier put dates, and the weighted-average rates as of December 31, 2017 .
Long-term Debt Maturities	The aggregate maturities of long-term debt, based on stated maturities or earlier put dates, for the periods 2018 through 2022 and thereafter are as follows: PPL PPL Electric LKE LG&E KU 2018 $ 348 $ — $ 98 $ 98 $ — 2019 430 — 430 334 96 2020 1,278 100 975 — 500 2021 1,150 400 250 — — 2022 1,274 474 — — — Thereafter 15,802 2,365 3,447 1,292 1,755 Total $ 20,282 $ 3,339 $ 5,200 $ 1,724 $ 2,351
Schedule Of Stock Offering Program	PPL issued the following for the years ended December 31: 2017 2016 2015 Number of shares (in thousands) 10,373 710 1,477 Net Proceeds $ 377 $ 25 $ 49

Acquisitions, Development and42

Acquisitions, Development and Divestures (Tables)	12 Months Ended
	Dec. 31, 2017
Acquisitions, Development and Divestitures [Line Items]
Components of Discontinued Operations	Following are the components of Discontinued Operations in the Statement of Income for the period ended December 31: 2015 Operating revenues $ 1,427 Operating expenses 1,328 Other Income (Expense) - net (21 ) Interest expense (a) 150 Income tax expense (benefit) (30 ) Loss on spinoff (879 ) Loss from Discontinued Operations (net of income taxes) $ (921 ) (a) Includes interest associated with the Supply segment with no additional allocation as the Supply segment was sufficiently capitalized. The following table summarizes PPL's fair value analysis: Approach Weighting Weighted Fair Value (in billions) Talen Energy Market Value 50% $ 1.4 Income/Discounted Cash Flow 30% 1.1 Alternative Market (Comparable Company) 20% 0.7 Estimated Fair Value $ 3.2

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Line Items]
Rent Expense for Operating Leases	Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11
Future Minimum Rental Payments for All Operating Leases	Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41
LG And E And KU Energy LLC [Member]
Leases [Line Items]
Rent Expense for Operating Leases	Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11
Future Minimum Rental Payments for All Operating Leases	Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41
Louisville Gas And Electric Co [Member]
Leases [Line Items]
Rent Expense for Operating Leases	Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11
Future Minimum Rental Payments for All Operating Leases	Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41
Kentucky Utilities Co [Member]
Leases [Line Items]
Rent Expense for Operating Leases	Rent expense for the years ended December 31 for operating leases was as follows: 2017 2016 2015 PPL $ 45 $ 50 $ 49 LKE 26 26 24 LG&E 15 15 12 KU 11 11 11
Future Minimum Rental Payments for All Operating Leases	Total future minimum rental payments for all operating leases are estimated to be: PPL LKE LG&E KU 2018 $ 32 $ 26 $ 15 $ 10 2019 19 16 8 8 2020 13 11 5 6 2021 10 8 3 5 2022 8 6 2 4 Thereafter 22 15 6 8 Total $ 104 $ 82 $ 39 $ 41

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Line Items]
Stock-Based Compensation, Plan Award Limits	The following table details the award limits under each of the Plans. Total Plan Annual Grant Limit Total As % of Outstanding Annual Grant Annual Grant Limit For Individual Participants - Performance Based Awards Award Limit PPL Common Stock On First Day of Limit Options For awards denominated in For awards denominated in Plan (Shares) Each Calendar Year (Shares) shares (Shares) cash (in dollars) SIP 15,000,000 2,000,000 750,000 $ 15,000,000 ICPKE 14,199,796 2 % 3,000,000
Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value	The weighted-average grant date fair value of restricted stock units granted was: 2017 2016 2015 PPL $ 35.30 $ 33.84 $ 34.50 PPL Electric 35.45 34.32 34.41 LKE 35.25 33.73 34.89
Restricted Stock and Restricted Stock Units, Activity Rollforward	Restricted stock unit activity for 2017 was: Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,337,025 $ 31.57 Granted 538,441 35.30 Vested (567,001 ) 29.28 Forfeited (16,816 ) 34.28 Nonvested, end of period (a) 1,291,649 34.10 Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Electric Nonvested, beginning of period 204,570 $ 31.27 Transfer between registrants (5,250 ) 32.05 Granted 79,321 35.45 Vested (91,117 ) 28.83 Forfeited (3,108 ) 34.68 Nonvested, end of period 184,416 34.20 LKE Nonvested, beginning of period 243,281 $ 31.53 Transfer between registrants 25,337 31.61 Granted 97,775 35.25 Vested (125,612 ) 29.68 Forfeited (9,224 ) 34.04 Nonvested, end of period 231,557 34.01 (a) Excludes 252,850 restricted stock units for which restrictions lapsed for former PPL Energy Supply employees as a result of the spinoff, but for which distribution will not occur until the end of the original restriction period of the awards.
Restricted Stock and Restricted Stock Units, Total Fair Value Vested at Year End	The total fair value of restricted stock units vesting for the years ended December 31 was: 2017 2016 2015 PPL $ 20 $ 30 $ 28 PPL Electric 3 3 4 LKE 4 5 4
Performance Units, Valuation Assumptions	The weighted-average assumptions used in the model were: 2017 2016 2015 Expected stock volatility 17.40 % 19.60 % 15.90 % Expected life 3 years 3 years 3 years
Performance Units, Weighted Average Grant Date Fair Value	The weighted-average grant date fair value of TSR performance units granted was: 2017 2016 2015 PPL $ 38.38 $ 35.74 $ 36.76 PPL Electric 38.37 35.68 37.93 LKE 38.24 35.28 37.10
Performance Units, Activity Rollforward	TSR performance unit activity for 2017 was: TSR Performance Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,070,536 $ 34.65 Granted 293,642 38.38 TSR Performance Units Weighted- Average Grant Date Fair Value Per Share Vested (243,983 ) 32.42 Forfeited (141,964 ) 32.27 Nonvested, end of period (a) 978,231 36.67 PPL Electric Nonvested, beginning of period 76,726 $ 34.68 Granted 26,086 38.37 Vested (14,713 ) 32.14 Forfeited (12,586 ) 35.45 Nonvested, end of period 75,513 37.00 LKE Nonvested, beginning of period 191,601 $ 34.34 Transfer between registrants 8,307 35.96 Granted 64,555 38.24 Vested (48,980 ) 32.09 Forfeited (35,194 ) 35.25 Nonvested, end of period 180,289 36.69 (a) Excludes 41,405 TSR awards for which the service vesting requirement was waived for former PPL Energy Supply employees as a result of the spinoff, but for which the ultimate number of shares to be distributed will depend on the actual attainment of the performance goals at the end of the specified performance periods. ROE performance unit activity for 2017 was: ROE Performance Unit Weighted- Average Grant Date Fair Value Per Share PPL Granted 97,925 $ 34.42 Forfeited (997 ) 34.41 Nonvested, end of period 96,928 34.42 PPL Electric Granted 8,696 $ 34.41 Nonvested, end of period 8,696 34.41 LKE Granted 21,536 $ 34.29 Forfeited (997 ) 34.41 Nonvested, end of period 20,539 34.29
Stock Options, Activity Rollforward	Stock option activity for 2017 was: Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value PPL Outstanding at beginning of period 4,481,160 $ 28.98 Exercised (718,977 ) 26.67 Outstanding and exercisable at end of period 3,762,183 29.42 3.5 $ 14 PPL Electric Outstanding at beginning of period 240,939 $ 27.48 Exercised (42,659 ) 26.99 Outstanding and exercisable at end of period 198,280 27.58 3.8 $ 1 Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value LKE Outstanding at beginning of period 61,896 $ 25.81 Exercised (28,164 ) 26.59 Outstanding and exercisable at end of period 33,732 25.15 4.1 $ —
Compensation Costs for Restricted Stock, Restricted Stock Units, Performance Units and Stock Options	Compensation expense for restricted stock, restricted stock units, performance units and stock options accounted for as equity awards, which for PPL Electric and LKE includes an allocation of PPL Services' expense, was: 2017 2016 2015 PPL $ 32 $ 27 $ 33 PPL Electric 18 16 14 LKE 8 7 8 The income tax benefit related to above compensation expense was as follows: 2017 2016 2015 PPL $ 13 $ 12 $ 14 PPL Electric 8 7 6 LKE 3 3 3
Unrecognized Compensation Cost, Nonvested Restricted Stock, Restricted Stock Units, Performance Units and Stock Option Awards	At December 31, 2017 , unrecognized compensation expense related to nonvested stock awards was: Unrecognized Compensation Expense Weighted- Average Period for Recognition PPL $ 10 1.7 PPL Electric 2 1.7 LKE 1 1.6
PPL Electric Utilities Corp [Member]
Disclosure Of Compensation Related Costs Sharebased Payments [Line Items]
Stock-Based Compensation, Plan Award Limits	The following table details the award limits under each of the Plans. Total Plan Annual Grant Limit Total As % of Outstanding Annual Grant Annual Grant Limit For Individual Participants - Performance Based Awards Award Limit PPL Common Stock On First Day of Limit Options For awards denominated in For awards denominated in Plan (Shares) Each Calendar Year (Shares) shares (Shares) cash (in dollars) SIP 15,000,000 2,000,000 750,000 $ 15,000,000 ICPKE 14,199,796 2 % 3,000,000
Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value	The weighted-average grant date fair value of restricted stock units granted was: 2017 2016 2015 PPL $ 35.30 $ 33.84 $ 34.50 PPL Electric 35.45 34.32 34.41 LKE 35.25 33.73 34.89
Restricted Stock and Restricted Stock Units, Activity Rollforward	Restricted stock unit activity for 2017 was: Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,337,025 $ 31.57 Granted 538,441 35.30 Vested (567,001 ) 29.28 Forfeited (16,816 ) 34.28 Nonvested, end of period (a) 1,291,649 34.10 Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Electric Nonvested, beginning of period 204,570 $ 31.27 Transfer between registrants (5,250 ) 32.05 Granted 79,321 35.45 Vested (91,117 ) 28.83 Forfeited (3,108 ) 34.68 Nonvested, end of period 184,416 34.20 LKE Nonvested, beginning of period 243,281 $ 31.53 Transfer between registrants 25,337 31.61 Granted 97,775 35.25 Vested (125,612 ) 29.68 Forfeited (9,224 ) 34.04 Nonvested, end of period 231,557 34.01 (a) Excludes 252,850 restricted stock units for which restrictions lapsed for former PPL Energy Supply employees as a result of the spinoff, but for which distribution will not occur until the end of the original restriction period of the awards.
Restricted Stock and Restricted Stock Units, Total Fair Value Vested at Year End	The total fair value of restricted stock units vesting for the years ended December 31 was: 2017 2016 2015 PPL $ 20 $ 30 $ 28 PPL Electric 3 3 4 LKE 4 5 4
Performance Units, Valuation Assumptions	The weighted-average assumptions used in the model were: 2017 2016 2015 Expected stock volatility 17.40 % 19.60 % 15.90 % Expected life 3 years 3 years 3 years
Performance Units, Weighted Average Grant Date Fair Value	The weighted-average grant date fair value of TSR performance units granted was: 2017 2016 2015 PPL $ 38.38 $ 35.74 $ 36.76 PPL Electric 38.37 35.68 37.93 LKE 38.24 35.28 37.10
Performance Units, Activity Rollforward	TSR performance unit activity for 2017 was: TSR Performance Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,070,536 $ 34.65 Granted 293,642 38.38 TSR Performance Units Weighted- Average Grant Date Fair Value Per Share Vested (243,983 ) 32.42 Forfeited (141,964 ) 32.27 Nonvested, end of period (a) 978,231 36.67 PPL Electric Nonvested, beginning of period 76,726 $ 34.68 Granted 26,086 38.37 Vested (14,713 ) 32.14 Forfeited (12,586 ) 35.45 Nonvested, end of period 75,513 37.00 LKE Nonvested, beginning of period 191,601 $ 34.34 Transfer between registrants 8,307 35.96 Granted 64,555 38.24 Vested (48,980 ) 32.09 Forfeited (35,194 ) 35.25 Nonvested, end of period 180,289 36.69 (a) Excludes 41,405 TSR awards for which the service vesting requirement was waived for former PPL Energy Supply employees as a result of the spinoff, but for which the ultimate number of shares to be distributed will depend on the actual attainment of the performance goals at the end of the specified performance periods. ROE performance unit activity for 2017 was: ROE Performance Unit Weighted- Average Grant Date Fair Value Per Share PPL Granted 97,925 $ 34.42 Forfeited (997 ) 34.41 Nonvested, end of period 96,928 34.42 PPL Electric Granted 8,696 $ 34.41 Nonvested, end of period 8,696 34.41 LKE Granted 21,536 $ 34.29 Forfeited (997 ) 34.41 Nonvested, end of period 20,539 34.29
Stock Options, Activity Rollforward	Stock option activity for 2017 was: Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value PPL Outstanding at beginning of period 4,481,160 $ 28.98 Exercised (718,977 ) 26.67 Outstanding and exercisable at end of period 3,762,183 29.42 3.5 $ 14 PPL Electric Outstanding at beginning of period 240,939 $ 27.48 Exercised (42,659 ) 26.99 Outstanding and exercisable at end of period 198,280 27.58 3.8 $ 1 Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value LKE Outstanding at beginning of period 61,896 $ 25.81 Exercised (28,164 ) 26.59 Outstanding and exercisable at end of period 33,732 25.15 4.1 $ —
Compensation Costs for Restricted Stock, Restricted Stock Units, Performance Units and Stock Options	Compensation expense for restricted stock, restricted stock units, performance units and stock options accounted for as equity awards, which for PPL Electric and LKE includes an allocation of PPL Services' expense, was: 2017 2016 2015 PPL $ 32 $ 27 $ 33 PPL Electric 18 16 14 LKE 8 7 8 The income tax benefit related to above compensation expense was as follows: 2017 2016 2015 PPL $ 13 $ 12 $ 14 PPL Electric 8 7 6 LKE 3 3 3
Unrecognized Compensation Cost, Nonvested Restricted Stock, Restricted Stock Units, Performance Units and Stock Option Awards	At December 31, 2017 , unrecognized compensation expense related to nonvested stock awards was: Unrecognized Compensation Expense Weighted- Average Period for Recognition PPL $ 10 1.7 PPL Electric 2 1.7 LKE 1 1.6
LG And E And KU Energy LLC [Member]
Disclosure Of Compensation Related Costs Sharebased Payments [Line Items]
Stock-Based Compensation, Plan Award Limits	The following table details the award limits under each of the Plans. Total Plan Annual Grant Limit Total As % of Outstanding Annual Grant Annual Grant Limit For Individual Participants - Performance Based Awards Award Limit PPL Common Stock On First Day of Limit Options For awards denominated in For awards denominated in Plan (Shares) Each Calendar Year (Shares) shares (Shares) cash (in dollars) SIP 15,000,000 2,000,000 750,000 $ 15,000,000 ICPKE 14,199,796 2 % 3,000,000
Restricted Stock and Restricted Stock Units, Weighted Average Grant Date Fair Value	The weighted-average grant date fair value of restricted stock units granted was: 2017 2016 2015 PPL $ 35.30 $ 33.84 $ 34.50 PPL Electric 35.45 34.32 34.41 LKE 35.25 33.73 34.89
Restricted Stock and Restricted Stock Units, Activity Rollforward	Restricted stock unit activity for 2017 was: Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,337,025 $ 31.57 Granted 538,441 35.30 Vested (567,001 ) 29.28 Forfeited (16,816 ) 34.28 Nonvested, end of period (a) 1,291,649 34.10 Restricted Shares/Units Weighted- Average Grant Date Fair Value Per Share PPL Electric Nonvested, beginning of period 204,570 $ 31.27 Transfer between registrants (5,250 ) 32.05 Granted 79,321 35.45 Vested (91,117 ) 28.83 Forfeited (3,108 ) 34.68 Nonvested, end of period 184,416 34.20 LKE Nonvested, beginning of period 243,281 $ 31.53 Transfer between registrants 25,337 31.61 Granted 97,775 35.25 Vested (125,612 ) 29.68 Forfeited (9,224 ) 34.04 Nonvested, end of period 231,557 34.01 (a) Excludes 252,850 restricted stock units for which restrictions lapsed for former PPL Energy Supply employees as a result of the spinoff, but for which distribution will not occur until the end of the original restriction period of the awards.
Restricted Stock and Restricted Stock Units, Total Fair Value Vested at Year End	The total fair value of restricted stock units vesting for the years ended December 31 was: 2017 2016 2015 PPL $ 20 $ 30 $ 28 PPL Electric 3 3 4 LKE 4 5 4
Performance Units, Valuation Assumptions	The weighted-average assumptions used in the model were: 2017 2016 2015 Expected stock volatility 17.40 % 19.60 % 15.90 % Expected life 3 years 3 years 3 years
Performance Units, Weighted Average Grant Date Fair Value	The weighted-average grant date fair value of TSR performance units granted was: 2017 2016 2015 PPL $ 38.38 $ 35.74 $ 36.76 PPL Electric 38.37 35.68 37.93 LKE 38.24 35.28 37.10
Performance Units, Activity Rollforward	TSR performance unit activity for 2017 was: TSR Performance Units Weighted- Average Grant Date Fair Value Per Share PPL Nonvested, beginning of period 1,070,536 $ 34.65 Granted 293,642 38.38 TSR Performance Units Weighted- Average Grant Date Fair Value Per Share Vested (243,983 ) 32.42 Forfeited (141,964 ) 32.27 Nonvested, end of period (a) 978,231 36.67 PPL Electric Nonvested, beginning of period 76,726 $ 34.68 Granted 26,086 38.37 Vested (14,713 ) 32.14 Forfeited (12,586 ) 35.45 Nonvested, end of period 75,513 37.00 LKE Nonvested, beginning of period 191,601 $ 34.34 Transfer between registrants 8,307 35.96 Granted 64,555 38.24 Vested (48,980 ) 32.09 Forfeited (35,194 ) 35.25 Nonvested, end of period 180,289 36.69 (a) Excludes 41,405 TSR awards for which the service vesting requirement was waived for former PPL Energy Supply employees as a result of the spinoff, but for which the ultimate number of shares to be distributed will depend on the actual attainment of the performance goals at the end of the specified performance periods. ROE performance unit activity for 2017 was: ROE Performance Unit Weighted- Average Grant Date Fair Value Per Share PPL Granted 97,925 $ 34.42 Forfeited (997 ) 34.41 Nonvested, end of period 96,928 34.42 PPL Electric Granted 8,696 $ 34.41 Nonvested, end of period 8,696 34.41 LKE Granted 21,536 $ 34.29 Forfeited (997 ) 34.41 Nonvested, end of period 20,539 34.29
Stock Options, Activity Rollforward	Stock option activity for 2017 was: Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value PPL Outstanding at beginning of period 4,481,160 $ 28.98 Exercised (718,977 ) 26.67 Outstanding and exercisable at end of period 3,762,183 29.42 3.5 $ 14 PPL Electric Outstanding at beginning of period 240,939 $ 27.48 Exercised (42,659 ) 26.99 Outstanding and exercisable at end of period 198,280 27.58 3.8 $ 1 Number of Options Weighted Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (years) Aggregate Total Intrinsic Value LKE Outstanding at beginning of period 61,896 $ 25.81 Exercised (28,164 ) 26.59 Outstanding and exercisable at end of period 33,732 25.15 4.1 $ —
Compensation Costs for Restricted Stock, Restricted Stock Units, Performance Units and Stock Options	Compensation expense for restricted stock, restricted stock units, performance units and stock options accounted for as equity awards, which for PPL Electric and LKE includes an allocation of PPL Services' expense, was: 2017 2016 2015 PPL $ 32 $ 27 $ 33 PPL Electric 18 16 14 LKE 8 7 8 The income tax benefit related to above compensation expense was as follows: 2017 2016 2015 PPL $ 13 $ 12 $ 14 PPL Electric 8 7 6 LKE 3 3 3
Unrecognized Compensation Cost, Nonvested Restricted Stock, Restricted Stock Units, Performance Units and Stock Option Awards	At December 31, 2017 , unrecognized compensation expense related to nonvested stock awards was: Unrecognized Compensation Expense Weighted- Average Period for Recognition PPL $ 10 1.7 PPL Electric 2 1.7 LKE 1 1.6

Retirement and Postemployment45

Retirement and Postemployment Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Schedule Of Net Periodic Defined Benefit Costs (Credits)	The following table provides the components of net periodic defined benefit costs for PPL's domestic (U.S.) and WPD's (U.K.) pension and other postretirement benefit plans for the years ended December 31. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 Net periodic defined benefit costs (credits): Service cost $ 65 $ 66 $ 96 $ 76 $ 69 $ 79 $ 7 $ 7 $ 11 Interest cost 168 174 194 178 235 314 23 26 26 Expected return on plan assets (231 ) (228 ) (258 ) (514 ) (504 ) (523 ) (22 ) (22 ) (26 ) Amortization of: Prior service cost (credit) 10 8 7 — — — (1 ) — 1 Actuarial (gain) loss 69 50 84 144 138 158 1 1 — Net periodic defined benefit costs (credits) prior to settlements and termination benefits 81 70 123 (116 ) (62 ) 28 8 12 12 Settlements 1 3 — — — — — — — Termination benefits 1 — — — — — — — — Net periodic defined benefit costs (credits) $ 83 $ 73 $ 123 $ (116 ) $ (62 ) $ 28 $ 8 $ 12 $ 12 Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: Divestiture (a) $ — $ — $ (353 ) $ — $ — $ — $ — $ — $ (6 ) Settlement (1 ) (3 ) — — — — — — — Net (gain) loss 27 253 63 346 7 508 (28 ) 9 (9 ) Prior service cost (credit) (1 ) 15 18 — — — 8 — — Amortization of: Prior service (cost) credit (10 ) (8 ) (7 ) — — — 1 (1 ) (1 ) Actuarial gain (loss) (69 ) (50 ) (85 ) (144 ) (138 ) (158 ) (1 ) (1 ) — Total recognized in OCI and regulatory assets/liabilities (b) (54 ) 207 (364 ) 202 (131 ) 350 (20 ) 7 (16 ) Total recognized in net periodic defined benefit costs, OCI and regulatory assets/liabilities (b) $ 29 $ 280 $ (241 ) $ 86 $ (193 ) $ 378 $ (12 ) $ 19 $ (4 ) (a) As a result of the spinoff of PPL Energy Supply, amounts in AOCI were allocated to certain former active and inactive employees of PPL Energy Supply and included in the distribution. See Note 8 for additional details. (b) WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. As a result, WPD does not record regulatory assets/liabilities.
Schedule of Amounts Recognized in Other Comprehensive Income and Regulatory Assets and Liabilities	For PPL's U.S. pension benefits and for other postretirement benefits, the amounts recognized in OCI and regulatory assets/liabilities for the years ended December 31 were as follows: U.S. Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 OCI $ (53 ) $ 236 $ (269 ) $ (25 ) $ 7 $ 12 Regulatory assets/liabilities (1 ) (29 ) (95 ) 5 — (28 ) Total recognized in OCI and regulatory assets/liabilities $ (54 ) $ 207 $ (364 ) $ (20 ) $ 7 $ (16 )
Schedule of Amounts to be Amortized from AOCI and Regulatory Assets/Liabilities in Next Fiscal Year	The estimated amounts to be amortized from AOCI and regulatory assets/liabilities into net periodic defined benefit costs in 2018 are as follows: Pension Benefits U.S. U.K. Prior service cost (credit) $ 10 $ — Actuarial (gain) loss 86 152 Total $ 96 $ 152 Amortization from Balance Sheet: AOCI $ 28 $ 152 Regulatory assets/liabilities 68 — Total $ 96 $ 152
Schedule of Net Periodic Defined Benefit Costs Included in Income Statement	The following net periodic defined benefit costs (credits) were charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 PPL $ 59 $ 53 $ 71 $ (151 ) $ (95 ) $ (21 ) $ 5 $ 7 $ 8 PPL Electric (a) 12 10 15 — 1 — LKE (b) 28 24 37 5 6 8 LG&E (b) 8 8 12 3 3 4 KU (a) (b) 4 5 9 1 2 2 (a) PPL Electric and KU do not directly sponsor any defined benefit plans. PPL Electric and KU were allocated these costs of defined benefit plans sponsored by PPL Services (for PPL Electric) and by LKE (for KU), based on their participation in those plans, which management believes are reasonable. KU is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to KU from LKS. (b) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between net periodic defined benefit costs calculated in accordance with LKE's, LG&E's and KU's pension accounting policy and the net periodic defined benefit costs calculated using a 15 year amortization period for gains and losses is recorded as a regulatory asset. Of the costs charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts, $4 million for LG&E and $2 million for KU were recorded as regulatory assets in 2017 , $3 million for LG&E and $2 million for KU were recorded as regulatory assets in 2016 and $4 million for LG&E and $1 million for KU were recorded as regulatory assets in 2015 .
Defined Benefit Plan Assumptions and Impact of One Point Change on Postretirement Plans	The following weighted-average assumptions were used in the valuation of the benefit obligations at December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2017 2016 2017 2016 PPL Discount rate 3.70 % 4.21 % 2.65 % 2.87 % 3.64 % 4.11 % Rate of compensation increase 3.78 % 3.95 % 3.50 % 3.50 % 3.75 % 3.92 % LKE Discount rate 3.69 % 4.19 % 3.65 % 4.12 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % LG&E Discount rate 3.65 % 4.13 % The following weighted-average assumptions were used to determine the net periodic defined benefit costs for the years ended December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 PPL Discount rate service cost (b) 4.21 % 4.59 % 4.25 % 2.99 % 3.90 % 3.85 % 4.11 % 4.48 % 4.09 % Discount rate interest cost (b) 4.21 % 4.59 % 4.25 % 2.41 % 3.14 % 3.85 % 4.11 % 4.48 % 4.09 % Rate of compensation increase 3.95 % 3.93 % 3.91 % 3.50 % 4.00 % 4.00 % 3.92 % 3.91 % 3.86 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 7.22 % 7.20 % 7.19 % 6.21 % 6.11 % 6.06 % LKE Discount rate 4.19 % 4.56 % 4.25 % 4.12 % 4.49 % 4.06 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 6.82 % 6.82 % 6.82 % Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 LG&E Discount rate 4.13 % 4.49 % 4.20 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % (a) The expected long-term rates of return for pension and other postretirement benefits are based on management's projections using a best-estimate of expected returns, volatilities and correlations for each asset class. Each plan's specific current and expected asset allocations are also considered in developing a reasonable return assumption. (b) As of January 1, 2016, WPD began using individual spot rates from the yield curve used to discount the benefit obligation to measure service cost and interest cost. PPL's U.S. plans use a single discount rate derived from an individual bond matching model to measure the benefit obligation, service cost and interest cost. See Note 1 for additional details. (PPL and LKE) The following table provides the assumed health care cost trend rates for the years ended December 31: 2017 2016 2015 PPL and LKE Health care cost trend rate assumed for next year – obligations 6.6 % 7.0 % 6.8 % – cost 7.0 % 6.8 % 7.2 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) – obligations 5.0 % 5.0 % 5.0 % – cost 5.0 % 5.0 % 5.0 % Year that the rate reaches the ultimate trend rate – obligations 2022 2022 2020 – cost 2022 2020 2020 A one percentage point change in the assumed health care costs trend rate assumption would have had the following effects on the other postretirement benefit plans in 2017 : One Percentage Point Increase Decrease Effect on accumulated postretirement benefit obligation PPL $ 4 $ (4 ) LKE 3 (3 )
Schedule of Funded Status of Defined Benefit Plans	The funded status of PPL's plans at December 31 was as follows: Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2017 2016 2017 2016 Change in Benefit Obligation Benefit Obligation, beginning of period $ 4,079 $ 3,863 $ 7,383 $ 8,404 $ 591 $ 596 Service cost 65 66 76 69 7 7 Interest cost 168 174 178 235 23 26 Participant contributions — — 13 14 14 14 Plan amendments (1 ) 14 — — 8 — Actuarial (gain) loss 233 214 293 484 4 11 Settlements (6 ) (9 ) (1 ) — — — Termination benefits 1 — — — — — Gross benefits paid (251 ) (243 ) (345 ) (357 ) (59 ) (64 ) Federal subsidy — — — — 1 1 Currency conversion — — 622 (1,466 ) — — Benefit Obligation, end of period 4,288 4,079 8,219 7,383 589 591 Change in Plan Assets Plan assets at fair value, beginning of period 3,243 3,227 7,211 7,625 378 379 Actual return on plan assets 437 189 480 979 54 25 Employer contributions 65 79 486 330 15 19 Participant contributions — — 13 14 13 14 Settlements (6 ) (9 ) (1 ) — — — Gross benefits paid (251 ) (243 ) (345 ) (357 ) (55 ) (59 ) Currency conversion — — 646 (1,380 ) — — Plan assets at fair value, end of period 3,488 3,243 8,490 7,211 405 378 Funded Status, end of period $ (800 ) $ (836 ) $ 271 $ (172 ) $ (184 ) $ (213 ) Amounts recognized in the Balance Sheets consist of: Noncurrent asset $ — $ — $ 284 $ 10 $ 2 $ 2 Current liability (13 ) (17 ) — — (3 ) (3 ) Noncurrent liability (787 ) (819 ) (13 ) (182 ) (183 ) (212 ) Net amount recognized, end of period $ (800 ) $ (836 ) $ 271 $ (172 ) $ (184 ) $ (213 ) Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax) consist of: Prior service cost (credit) $ 49 $ 59 $ — $ — $ 9 $ — Net actuarial (gain) loss 1,134 1,178 2,755 2,553 16 45 Total (a) $ 1,183 $ 1,237 $ 2,755 $ 2,553 $ 25 $ 45 Total accumulated benefit obligation for defined benefit pension plans $ 4,000 $ 3,807 $ 7,542 $ 6,780 (a) WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP and as a result, does not record regulatory assets/liabilities. For PPL's U.S. pension and other postretirement benefit plans, the amounts recognized in AOCI and regulatory assets/liabilities at December 31 were as follows: U.S. Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 AOCI $ 374 $ 357 $ 15 $ 20 Regulatory assets/liabilities 809 880 10 25 Total $ 1,183 $ 1,237 $ 25 $ 45
Schedule of Projected or Accumulated Benefit Obligations In Excess of Plan Assets	The following tables provide information on pension plans where the projected benefit obligation (PBO) or accumulated benefit obligation (ABO) exceed the fair value of plan assets: U.S. U.K. PBO in excess of plan assets PBO in excess of plan assets 2017 2016 2017 2016 Projected benefit obligation $ 4,288 $ 4,079 $ 3,083 $ 3,403 Fair value of plan assets 3,488 3,243 3,070 3,221 U.S. U.K. ABO in excess of plan assets ABO in excess of plan assets 2017 2016 2017 2016 Accumulated benefit obligation $ 4,000 $ 3,807 $ 10 $ 657 Fair value of plan assets 3,488 3,243 — 643
Schedules of Asset Allocation of U.S. Pension Trusts Assets	The asset allocation for the trust and the target allocation by portfolio at December 31 are as follows: Percentage of trust assets 2017 2017 (a) 2016 Target Asset Allocation (a) Growth Portfolio 56 % 52 % 55 % Equity securities 32 % 30 % Debt securities (b) 14 % 12 % Alternative investments 10 % 10 % Immunizing Portfolio 43 % 46 % 43 % Debt securities (b) 39 % 43 % Derivatives 4 % 3 % Liquidity Portfolio 1 % 2 % 2 % Total 100 % 100 % 100 % (a) Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan. (b) Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.
Schedule of Fair Value of Financial Assets for U.S. Pension Plan Assets	The fair value of net assets in the Master Trust by asset class and level within the fair value hierarchy was: December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 PPL Services Corporation Master Trust Cash and cash equivalents $ 301 $ 301 $ — $ — $ 181 $ 181 $ — $ — Equity securities: U.S. Equity 229 229 — — 152 152 — — U.S. Equity fund measured at NAV (a) 364 — — — 272 — — — International equity fund at NAV (a) 538 — — — 551 — — — Commingled debt measured at NAV (a) 611 — — — 546 — — — December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Debt securities: U.S. Treasury and U.S. government sponsored agency 186 186 — — 381 381 — — Corporate 883 — 870 13 850 — 837 13 Other 10 — 10 — 8 — 8 — Alternative investments: Real estate measured at NAV (a) 109 — — — 102 — — — Private equity measured at NAV (a) 80 — — — 80 — — — Hedge funds measured at NAV (a) 175 — — — 167 — — — Derivatives: Interest rate swaps and swaptions 50 — 50 — 61 — 61 — Other 1 — 1 — 3 — 3 — Insurance contracts 24 — — 24 27 — — 27 PPL Services Corporation Master Trust assets, at fair value 3,561 $ 716 $ 931 $ 37 3,381 $ 714 $ 909 $ 40 Receivables and payables, net (b) 72 (15 ) 401(h) accounts restricted for other postretirement benefit obligations (145 ) (123 ) Total PPL Services Corporation Master Trust pension assets $ 3,488 $ 3,243 (a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. (b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.
Reconciliation of U.S. Pension Trust Assets Classified as Level 3 Included in Earnings	A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2017 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 13 $ 27 $ 40 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements — (4 ) (4 ) Balance at end of period $ 13 $ 24 $ 37 A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2016 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 10 $ 32 $ 42 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements 3 (6 ) (3 ) Balance at end of period $ 13 $ 27 $ 40
Schedules of Target Allocation of U.S. Other Postretirement Benefit Plans VEBA Trust	The asset allocation for the PPL VEBA trusts, excluding LKE, and the target allocation, by asset class, at December 31 are detailed below. Percentage of plan assets Target Asset Allocation 2017 2016 2017 Asset Class U.S. Equity securities 47 % 48 % 45 % Debt securities (a) 49 % 50 % 50 % Cash and cash equivalents (b) 4 % 2 % 5 % Total 100 % 100 % 100 % (a) Includes commingled debt funds and debt securities. (b) Includes money market funds.
Schedule of Fair Value of Financial Assets for U.S. Postretirement Benefits	The fair value of assets in the U.S. other postretirement benefit plans by asset class and level within the fair value hierarchy was: December 31, 2017 December 31, 2016 Fair Value Measurement Using Fair Value Measurement Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Money market funds $ 10 $ 10 $ — $ — $ 5 $ 5 $ — $ — U.S. Equity securities: Large-cap equity fund measure at NAV (a) 123 — — — 123 — — — Commingled debt fund measured at NAV (a) 96 — — — 114 — — — Debt securities: Corporate bonds 30 — 30 — — — — — Municipalities — — — — 12 — 12 — Total VEBA trust assets, at fair value 259 $ 10 $ 30 $ — 254 $ 5 $ 12 $ — Receivables and payables, net (b) 1 1 401(h) account assets 145 123 Total other postretirement benefit plan assets $ 405 $ 378 (a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. (b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.
Schedules of Asset Allocation of U.K. Pension Plan Assets	The asset allocation and target allocation at December 31 of WPD's pension plans are detailed below. Target Asset Percentage of plan assets Allocation 2017 2016 2017 Asset Class Cash and cash equivalents 2 % 1 % — % Equity securities U.K. 2 % 3 % 2 % European (excluding the U.K.) 1 % 2 % 1 % Asian-Pacific 1 % 2 % 1 % North American 1 % 3 % 1 % Emerging markets 1 % 3 % 1 % Global equities 16 % 6 % 10 % Global Tactical Asset Allocation 33 % 33 % 41 % Debt securities (a) 37 % 41 % 38 % Alternative investments 6 % 6 % 5 % Total 100 % 100 % 100 % (a) Includes commingled debt funds.
Schedule of Fair Value of Financial Assets for U.K. Pension Plan Assets	The fair value of assets in the U.K. pension plans by asset class and level within the fair value hierarchy was: December 31, 2017 December 31, 2016 Fair Value Measurement Using Fair Value Measurement Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 216 $ 216 $ — $ — $ 42 $ 42 $ — $ — Equity securities measured at NAV (a) : U.K. companies 157 — — — 210 — — — European companies (excluding the U.K.) 98 — — — 177 — — — Asian-Pacific companies 60 — — — 140 — — — North American companies 123 — — — 227 — — — Emerging markets companies 62 — — — 209 — — — Global Equities 1,335 — — — 466 — — — Other 2,807 — — — 2,363 — — — Debt Securities: U.K. corporate bonds 3 — 3 — 2 — 2 — U.K. gilts 3,137 — 3,137 — 2,940 — 2,940 — Alternative investments: Real estate measured at NAV (a) 492 — — — 435 — — — Fair value - U.K. pension plans $ 8,490 $ 216 $ 3,140 $ — $ 7,211 $ 42 $ 2,942 $ — (a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.
Schedule of Expected Cash Flows - U.S. Defined Benefit Plans - Expected Payments and Related Federal Subsidy	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans and the following federal subsidy payments are expected to be received by PPL. Other Postretirement Pension Benefit Payment Expected Federal Subsidy 2018 $ 260 $ 51 $ 1 2019 269 51 — 2020 268 50 1 2021 270 49 — 2022 272 48 — 2023-2027 1,328 218 2
Schedule of Expected Cash Flows - U.K. Pension Plans - Expected Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans. Pension 2018 $ 343 2019 349 2020 353 2021 356 2022 362 2023-2027 1,843
Expected Employer Contributions to U.S. Savings Plans	Substantially all employees of PPL's subsidiaries are eligible to participate in deferred savings plans (401(k)s). Employer contributions to the plans were: 2017 2016 2015 PPL $ 36 $ 35 $ 34 PPL Electric 6 6 6 LKE 18 17 16 LG&E 5 5 5 KU 4 4 4
PPL Electric Utilities Corp [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Funded Status of Defined Benefit Plans	Allocations to PPL Electric resulted in liabilities at December 31 as follows: 2017 2016 Pension $ 246 $ 281 Other postretirement benefits 62 72
LG And E And KU Energy LLC [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule Of Net Periodic Defined Benefit Costs (Credits)	The following table provides the components of net periodic defined benefit costs for LKE's pension and other postretirement benefit plans for the years ended December 31. Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 Net periodic defined benefit costs (credits): Service cost $ 24 $ 23 $ 26 $ 4 $ 5 $ 5 Interest cost 68 71 68 9 9 9 Expected return on plan assets (92 ) (91 ) (88 ) (7 ) (6 ) (6 ) Amortization of: Prior service cost 8 8 7 1 3 3 Actuarial (gain) loss (a) 31 21 37 — (1 ) — Net periodic defined benefit costs (b) $ 39 $ 32 $ 50 $ 7 $ 10 $ 11 Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: Net (gain) loss $ 30 $ 119 $ 20 $ (14 ) $ 6 $ (15 ) Prior service cost 7 — 19 8 — — Amortization of: Prior service credit (8 ) (8 ) (7 ) (1 ) (3 ) (3 ) Actuarial gain (loss) (32 ) (21 ) (37 ) — 1 — Total recognized in OCI and regulatory assets/liabilities (3 ) 90 (5 ) (7 ) 4 (18 ) Total recognized in net periodic defined benefit costs, OCI and regulatory assets/liabilities $ 36 $ 122 $ 45 $ — $ 14 $ (7 ) (a) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LKE's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $11 million in 2017 , $6 million in 2016 and $9 million in 2015 . (b) Due to the amount of lump sum payment distributions from the LG&E qualified pension plan, a settlement charge of $5 million was incurred. In accordance with existing regulatory accounting treatment, LG&E has maintained the settlement charge in regulatory assets. The amount will be amortized in accordance with existing regulatory practice.
Schedule of Amounts Recognized in Other Comprehensive Income and Regulatory Assets and Liabilities	For LKE's pension and other postretirement benefits, the amounts recognized in OCI and regulatory assets/liabilities for the years ended December 31 were as follows: Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 OCI $ 33 $ 42 $ 4 $ (2 ) $ 2 $ (2 ) Regulatory assets/liabilities (36 ) 48 (9 ) (5 ) 2 (16 ) Total recognized in OCI and regulatory assets/liabilities $ (3 ) $ 90 $ (5 ) $ (7 ) $ 4 $ (18 )
Schedule of Amounts to be Amortized from AOCI and Regulatory Assets/Liabilities in Next Fiscal Year	The estimated amounts to be amortized from AOCI and regulatory assets/liabilities into net periodic defined benefit costs for LKE in 2018 are as follows. Pension Benefits Other Postretirement Benefits Prior service cost $ 9 $ 1 Actuarial Loss 39 — Total $ 48 $ 1 Amortization from Balance Sheet: AOCI $ 11 $ — Regulatory assets/liabilities 37 1 Total $ 48 $ 1
Defined Benefit Plan Assumptions and Impact of One Point Change on Postretirement Plans	The following weighted-average assumptions were used in the valuation of the benefit obligations at December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2017 2016 2017 2016 PPL Discount rate 3.70 % 4.21 % 2.65 % 2.87 % 3.64 % 4.11 % Rate of compensation increase 3.78 % 3.95 % 3.50 % 3.50 % 3.75 % 3.92 % LKE Discount rate 3.69 % 4.19 % 3.65 % 4.12 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % LG&E Discount rate 3.65 % 4.13 % The following weighted-average assumptions were used to determine the net periodic defined benefit costs for the years ended December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 PPL Discount rate service cost (b) 4.21 % 4.59 % 4.25 % 2.99 % 3.90 % 3.85 % 4.11 % 4.48 % 4.09 % Discount rate interest cost (b) 4.21 % 4.59 % 4.25 % 2.41 % 3.14 % 3.85 % 4.11 % 4.48 % 4.09 % Rate of compensation increase 3.95 % 3.93 % 3.91 % 3.50 % 4.00 % 4.00 % 3.92 % 3.91 % 3.86 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 7.22 % 7.20 % 7.19 % 6.21 % 6.11 % 6.06 % LKE Discount rate 4.19 % 4.56 % 4.25 % 4.12 % 4.49 % 4.06 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 6.82 % 6.82 % 6.82 % Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 LG&E Discount rate 4.13 % 4.49 % 4.20 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % (a) The expected long-term rates of return for pension and other postretirement benefits are based on management's projections using a best-estimate of expected returns, volatilities and correlations for each asset class. Each plan's specific current and expected asset allocations are also considered in developing a reasonable return assumption. (b) As of January 1, 2016, WPD began using individual spot rates from the yield curve used to discount the benefit obligation to measure service cost and interest cost. PPL's U.S. plans use a single discount rate derived from an individual bond matching model to measure the benefit obligation, service cost and interest cost. See Note 1 for additional details. (PPL and LKE) The following table provides the assumed health care cost trend rates for the years ended December 31: 2017 2016 2015 PPL and LKE Health care cost trend rate assumed for next year – obligations 6.6 % 7.0 % 6.8 % – cost 7.0 % 6.8 % 7.2 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) – obligations 5.0 % 5.0 % 5.0 % – cost 5.0 % 5.0 % 5.0 % Year that the rate reaches the ultimate trend rate – obligations 2022 2022 2020 – cost 2022 2020 2020 A one percentage point change in the assumed health care costs trend rate assumption would have had the following effects on the other postretirement benefit plans in 2017 : One Percentage Point Increase Decrease Effect on accumulated postretirement benefit obligation PPL $ 4 $ (4 ) LKE 3 (3 )
Schedule of Funded Status of Defined Benefit Plans	The funded status of LKE's plans at December 31 was as follows: Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 Change in Benefit Obligation Benefit Obligation, beginning of period $ 1,669 $ 1,588 $ 220 $ 216 Service cost 24 23 4 5 Interest cost 68 71 9 9 Participant contributions — — 8 7 Plan amendments (a) 6 — 8 — Actuarial (gain) loss 113 96 (7 ) 4 Gross benefits paid (a) (109 ) (109 ) (19 ) (21 ) Benefit Obligation, end of period 1,771 1,669 223 220 Change in Plan Assets Plan assets at fair value, beginning of period 1,315 1,289 98 88 Actual return on plan assets 175 69 14 4 Employer contributions 21 66 15 20 Participant contributions — — 8 7 Gross benefits paid (109 ) (109 ) (19 ) (21 ) Plan assets at fair value, end of period 1,402 1,315 116 98 Funded Status, end of period $ (369 ) $ (354 ) $ (107 ) $ (122 ) Amounts recognized in the Balance Sheets consist of: Noncurrent asset $ — $ — $ 2 $ 2 Current liability (4 ) (4 ) (3 ) (3 ) Noncurrent liability (365 ) (350 ) (106 ) (121 ) Net amount recognized, end of period $ (369 ) $ (354 ) $ (107 ) $ (122 ) Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax) consist of: Prior service cost $ 44 $ 45 $ 13 $ 6 Net actuarial (gain) loss 434 436 (26 ) (13 ) Total $ 478 $ 481 $ (13 ) $ (7 ) Total accumulated benefit obligation for defined benefit pension plans $ 1,616 $ 1,531 (a) The pension plans were amended in December 2015 to allow active participants and terminated vested participants who had not previously elected a form of payment of their benefit to elect to receive their accrued pension benefit as a one-time lump-sum payment effective January 1, 2016. The projected benefit obligation at December 31, 2016 increased by $19 million as a result of the amendment. Gross benefits paid by the plans include lump-sum cash payments made to participants during 2017 and 2016 of $50 million and $53 million in connection with these offerings. The amounts recognized in AOCI and regulatory assets/liabilities at December 31 were as follows: Pension Benefits Other Postretirement Benefits 2017 2016 2017 2016 AOCI $ 144 $ 111 $ 6 $ 8 Regulatory assets/liabilities 334 370 (19 ) (15 ) Total $ 478 $ 481 $ (13 ) $ (7 )
Schedule of Projected or Accumulated Benefit Obligations In Excess of Plan Assets	The following tables provide information on pension plans where the projected benefit obligation (PBO) or accumulated benefit obligations (ABO) exceed the fair value of plan assets: PBO in excess of plan assets 2017 2016 Projected benefit obligation $ 1,771 $ 1,669 Fair value of plan assets 1,402 1,315 ABO in excess of plan assets 2017 2016 Accumulated benefit obligation $ 1,616 $ 1,531 Fair value of plan assets 1,402 1,315
Schedules of Asset Allocation of U.S. Pension Trusts Assets	The asset allocation for the trust and the target allocation by portfolio at December 31 are as follows: Percentage of trust assets 2017 2017 (a) 2016 Target Asset Allocation (a) Growth Portfolio 56 % 52 % 55 % Equity securities 32 % 30 % Debt securities (b) 14 % 12 % Alternative investments 10 % 10 % Immunizing Portfolio 43 % 46 % 43 % Debt securities (b) 39 % 43 % Derivatives 4 % 3 % Liquidity Portfolio 1 % 2 % 2 % Total 100 % 100 % 100 % (a) Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan. (b) Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.
Schedule of Fair Value of Financial Assets for U.S. Pension Plan Assets	The fair value of net assets in the Master Trust by asset class and level within the fair value hierarchy was: December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 PPL Services Corporation Master Trust Cash and cash equivalents $ 301 $ 301 $ — $ — $ 181 $ 181 $ — $ — Equity securities: U.S. Equity 229 229 — — 152 152 — — U.S. Equity fund measured at NAV (a) 364 — — — 272 — — — International equity fund at NAV (a) 538 — — — 551 — — — Commingled debt measured at NAV (a) 611 — — — 546 — — — December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Debt securities: U.S. Treasury and U.S. government sponsored agency 186 186 — — 381 381 — — Corporate 883 — 870 13 850 — 837 13 Other 10 — 10 — 8 — 8 — Alternative investments: Real estate measured at NAV (a) 109 — — — 102 — — — Private equity measured at NAV (a) 80 — — — 80 — — — Hedge funds measured at NAV (a) 175 — — — 167 — — — Derivatives: Interest rate swaps and swaptions 50 — 50 — 61 — 61 — Other 1 — 1 — 3 — 3 — Insurance contracts 24 — — 24 27 — — 27 PPL Services Corporation Master Trust assets, at fair value 3,561 $ 716 $ 931 $ 37 3,381 $ 714 $ 909 $ 40 Receivables and payables, net (b) 72 (15 ) 401(h) accounts restricted for other postretirement benefit obligations (145 ) (123 ) Total PPL Services Corporation Master Trust pension assets $ 3,488 $ 3,243 (a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. (b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.
Reconciliation of U.S. Pension Trust Assets Classified as Level 3 Included in Earnings	A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2017 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 13 $ 27 $ 40 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements — (4 ) (4 ) Balance at end of period $ 13 $ 24 $ 37 A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2016 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 10 $ 32 $ 42 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements 3 (6 ) (3 ) Balance at end of period $ 13 $ 27 $ 40
Schedule of Fair Value of Financial Assets for U.S. Postretirement Benefits	The fair value of assets in the U.S. other postretirement benefit plans by asset class and level within the fair value hierarchy was: December 31, 2017 December 31, 2016 Fair Value Measurement Using Fair Value Measurement Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Money market funds $ 10 $ 10 $ — $ — $ 5 $ 5 $ — $ — U.S. Equity securities: Large-cap equity fund measure at NAV (a) 123 — — — 123 — — — Commingled debt fund measured at NAV (a) 96 — — — 114 — — — Debt securities: Corporate bonds 30 — 30 — — — — — Municipalities — — — — 12 — 12 — Total VEBA trust assets, at fair value 259 $ 10 $ 30 $ — 254 $ 5 $ 12 $ — Receivables and payables, net (b) 1 1 401(h) account assets 145 123 Total other postretirement benefit plan assets $ 405 $ 378 (a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. (b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.
Schedule of Expected Cash Flows - U.S. Defined Benefit Plans - Expected Payments and Related Federal Subsidy	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans and the following federal subsidy payments are expected to be received by LKE. Other Postretirement Pension Benefit Payment Expected Federal Subsidy 2018 $ 109 $ 14 $ — 2019 113 15 — 2020 114 16 1 2021 115 16 — 2022 116 16 — 2023-2027 573 79 2
Louisville Gas And Electric Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule Of Net Periodic Defined Benefit Costs (Credits)	The following table provides the components of net periodic defined benefit costs for LG&E's pension benefit plan for the years ended December 31. Pension Benefits 2017 2016 2015 Net periodic defined benefit costs (credits): Service cost $ 1 $ 1 $ 1 Interest cost 13 15 14 Expected return on plan assets (22 ) (21 ) (20 ) Amortization of: Prior service cost 5 4 3 Actuarial loss (a) 9 7 11 Net periodic defined benefit costs (b) $ 6 $ 6 $ 9 Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets - Gross: Net (gain) loss $ (9 ) $ 22 $ 8 Prior service cost 7 — 10 Amortization of: Prior service credit (5 ) (4 ) (3 ) Actuarial gain (9 ) (7 ) (11 ) Total recognized in regulatory assets/liabilities (16 ) 11 4 Total recognized in net periodic defined benefit costs and regulatory assets $ (10 ) $ 17 $ 13 (a) As a result of the 2014 Kentucky rate case settlement that became effective July 1, 2015, the difference between actuarial (gain)/loss calculated in accordance with LG&E's pension accounting policy and actuarial (gain)/loss calculated using a 15 year amortization period was $7 million in 2017 , $5 million in 2016 and $3 million in 2015 . (b) Due to the amount of lump sum payment distributions from the LG&E qualified pension plan, a settlement charge of $5 million was incurred. In accordance with existing regulatory accounting treatment, LG&E has maintained the settlement charge in regulatory assets. The amount will be amortized in accordance with existing regulatory practice.
Schedule of Amounts to be Amortized from AOCI and Regulatory Assets/Liabilities in Next Fiscal Year	The estimated amounts to be amortized from regulatory assets into net periodic defined benefit costs for LG&E in 2018 are as follows. Pension Benefits Prior service cost $ 5 Actuarial loss 9 Total $ 14
Schedule of Net Periodic Defined Benefit Costs Included in Income Statement	In the table above, LG&E amounts include costs for the specific plans it sponsors and the following allocated costs of defined benefit plans sponsored by LKE. LG&E is also allocated costs of defined benefit plans from LKS for defined benefit plans sponsored by LKE. See Note 14 for additional information on costs allocated to LG&E from LKS. These allocations are based on LG&E's participation in those plans, which management believes are reasonable: Pension Benefits Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 LG&E Non-Union Only $ 5 $ 4 $ 5 $ 3 $ 3 $ 4
Defined Benefit Plan Assumptions and Impact of One Point Change on Postretirement Plans	The following weighted-average assumptions were used in the valuation of the benefit obligations at December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2017 2016 2017 2016 PPL Discount rate 3.70 % 4.21 % 2.65 % 2.87 % 3.64 % 4.11 % Rate of compensation increase 3.78 % 3.95 % 3.50 % 3.50 % 3.75 % 3.92 % LKE Discount rate 3.69 % 4.19 % 3.65 % 4.12 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % LG&E Discount rate 3.65 % 4.13 % The following weighted-average assumptions were used to determine the net periodic defined benefit costs for the years ended December 31. The U.K. pension benefits apply to PPL only. Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 PPL Discount rate service cost (b) 4.21 % 4.59 % 4.25 % 2.99 % 3.90 % 3.85 % 4.11 % 4.48 % 4.09 % Discount rate interest cost (b) 4.21 % 4.59 % 4.25 % 2.41 % 3.14 % 3.85 % 4.11 % 4.48 % 4.09 % Rate of compensation increase 3.95 % 3.93 % 3.91 % 3.50 % 4.00 % 4.00 % 3.92 % 3.91 % 3.86 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 7.22 % 7.20 % 7.19 % 6.21 % 6.11 % 6.06 % LKE Discount rate 4.19 % 4.56 % 4.25 % 4.12 % 4.49 % 4.06 % Rate of compensation increase 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % 3.50 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % 6.82 % 6.82 % 6.82 % Pension Benefits U.S. U.K. Other Postretirement Benefits 2017 2016 2015 2017 2016 2015 2017 2016 2015 LG&E Discount rate 4.13 % 4.49 % 4.20 % Expected return on plan assets (a) 7.00 % 7.00 % 7.00 % (a) The expected long-term rates of return for pension and other postretirement benefits are based on management's projections using a best-estimate of expected returns, volatilities and correlations for each asset class. Each plan's specific current and expected asset allocations are also considered in developing a reasonable return assumption. (b) As of January 1, 2016, WPD began using individual spot rates from the yield curve used to discount the benefit obligation to measure service cost and interest cost. PPL's U.S. plans use a single discount rate derived from an individual bond matching model to measure the benefit obligation, service cost and interest cost. See Note 1 for additional details.
Schedule of Funded Status of Defined Benefit Plans	(LG&E) The funded status of LG&E's plan at December 31, was as follows: Pension Benefits 2017 2016 Change in Benefit Obligation Benefit Obligation, beginning of period $ 329 $ 326 Service cost 1 1 Interest cost 13 15 Plan amendments (a) 6 — Actuarial (gain) loss 11 15 Gross benefits paid (a) (34 ) (28 ) Benefit Obligation, end of period 326 329 Change in Plan Assets Plan assets at fair value, beginning of period 318 297 Actual return on plan assets 41 14 Employer contributions — 35 Gross benefits paid (34 ) (28 ) Plan assets at fair value, end of period 325 318 Funded Status, end of period $ (1 ) $ (11 ) Amounts recognized in the Balance Sheets consist of: Noncurrent liability $ (1 ) $ (11 ) Net amount recognized, end of period $ (1 ) $ (11 ) Amounts recognized in regulatory assets (pre-tax) consist of: Prior service cost $ 27 $ 25 Net actuarial loss 92 110 Total $ 119 $ 135 Total accumulated benefit obligation for defined benefit pension plan $ 326 $ 329 (a) The pension plan was amended in December 2015 to allow active participants and terminated vested participants who had not previously elected a form of payment of their benefit to elect to receive their accrued pension benefit as a one-time lump-sum payment effective January 1, 2016. The projected benefit obligation at December 31, 2015 increased by $10 million as a result of the amendment. Gross benefits paid by the plan include lump-sum cash payments made to participants during 2017 and 2016 of $19 million and $14 million in connection with this offering. Allocations to LG&E resulted in liabilities at December 31 as follows: 2017 2016 Pension $ 44 $ 42 Other postretirement benefits 74 76
Schedules of Asset Allocation of U.S. Pension Trusts Assets	The asset allocation for the trust and the target allocation by portfolio at December 31 are as follows: Percentage of trust assets 2017 2017 (a) 2016 Target Asset Allocation (a) Growth Portfolio 56 % 52 % 55 % Equity securities 32 % 30 % Debt securities (b) 14 % 12 % Alternative investments 10 % 10 % Immunizing Portfolio 43 % 46 % 43 % Debt securities (b) 39 % 43 % Derivatives 4 % 3 % Liquidity Portfolio 1 % 2 % 2 % Total 100 % 100 % 100 % (a) Allocations exclude consideration of a group annuity contract held by the LG&E and KU Retirement Plan. (b) Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.
Schedule of Fair Value of Financial Assets for U.S. Pension Plan Assets	The fair value of net assets in the Master Trust by asset class and level within the fair value hierarchy was: December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 PPL Services Corporation Master Trust Cash and cash equivalents $ 301 $ 301 $ — $ — $ 181 $ 181 $ — $ — Equity securities: U.S. Equity 229 229 — — 152 152 — — U.S. Equity fund measured at NAV (a) 364 — — — 272 — — — International equity fund at NAV (a) 538 — — — 551 — — — Commingled debt measured at NAV (a) 611 — — — 546 — — — December 31, 2017 December 31, 2016 Fair Value Measurements Using Fair Value Measurements Using Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Debt securities: U.S. Treasury and U.S. government sponsored agency 186 186 — — 381 381 — — Corporate 883 — 870 13 850 — 837 13 Other 10 — 10 — 8 — 8 — Alternative investments: Real estate measured at NAV (a) 109 — — — 102 — — — Private equity measured at NAV (a) 80 — — — 80 — — — Hedge funds measured at NAV (a) 175 — — — 167 — — — Derivatives: Interest rate swaps and swaptions 50 — 50 — 61 — 61 — Other 1 — 1 — 3 — 3 — Insurance contracts 24 — — 24 27 — — 27 PPL Services Corporation Master Trust assets, at fair value 3,561 $ 716 $ 931 $ 37 3,381 $ 714 $ 909 $ 40 Receivables and payables, net (b) 72 (15 ) 401(h) accounts restricted for other postretirement benefit obligations (145 ) (123 ) Total PPL Services Corporation Master Trust pension assets $ 3,488 $ 3,243 (a) In accordance with accounting guidance certain investments that are measured at fair value using the net asset value per share (NAV), or its equivalent, practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. (b) Receivables and payables represent amounts for investments sold/purchased but not yet settled along with interest and dividends earned but not yet received.
Reconciliation of U.S. Pension Trust Assets Classified as Level 3 Included in Earnings	A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2017 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 13 $ 27 $ 40 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements — (4 ) (4 ) Balance at end of period $ 13 $ 24 $ 37 A reconciliation of the Master Trust assets classified as Level 3 at December 31, 2016 is as follows: Corporate debt Insurance contracts Total Balance at beginning of period $ 10 $ 32 $ 42 Actual return on plan assets Relating to assets still held at the reporting date — 1 1 Purchases, sales and settlements 3 (6 ) (3 ) Balance at end of period $ 13 $ 27 $ 40
Schedule of Expected Cash Flows - U.S. Defined Benefit Plans - Expected Payments and Related Federal Subsidy	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plan. Pension 2018 $ 26 2019 26 2020 26 2021 25 2022 24 2023-2027 104
Kentucky Utilities Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Funded Status of Defined Benefit Plans	Allocations to KU resulted in liabilities at December 31 as follows. 2017 2016 Pension $ 36 $ 62 Other postretirement benefits 32 40

Jointly Owned Utility Facilitie

Jointly Owned Utility Facilities (Tables)	12 Months Ended
	Dec. 31, 2017
Jointly Owned Facilities [Line Items]
Jointly Owned Utility Facilities	At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — —
LG And E And KU Energy LLC [Member]
Jointly Owned Facilities [Line Items]
Jointly Owned Utility Facilities	At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — —
Louisville Gas And Electric Co [Member]
Jointly Owned Facilities [Line Items]
Jointly Owned Utility Facilities	At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — —
Kentucky Utilities Co [Member]
Jointly Owned Facilities [Line Items]
Jointly Owned Utility Facilities	At December 31, 2017 and 2016 , the Balance Sheets reflect the owned interests in the facilities listed below. Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress PPL and LKE December 31, 2017 Generating Plants Trimble County Unit 1 75.00 % $ 427 $ 69 $ 1 Trimble County Unit 2 75.00 % 1,032 176 198 December 31, 2016 Generating Plants Trimble County Unit 1 75.00 % $ 407 $ 55 $ 1 Trimble County Unit 2 75.00 % 1,026 161 83 LG&E December 31, 2017 Generating Plants E.W. Brown Units 6-7 38.00 % $ 41 $ 17 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 52 15 — Trimble County Unit 1 75.00 % 427 69 1 Trimble County Unit 2 14.25 % 215 36 102 Trimble County Units 5-6 29.00 % 32 9 — Trimble County Units 7-10 37.00 % 73 21 — Cane Run Unit 7 22.00 % 120 8 1 E.W. Brown Solar Unit 39.00 % 10 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 38.00 % $ 40 $ 15 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 53.00 % 55 12 1 Trimble County Unit 1 75.00 % 407 55 1 Trimble County Unit 2 14.25 % 214 32 43 Trimble County Units 5-6 29.00 % 30 8 1 Trimble County Units 7-10 37.00 % 71 17 1 Cane Run Unit 7 22.00 % 114 5 2 E.W. Brown Solar Unit 39.00 % 10 — — Ownership Interest Electric Plant Accumulated Depreciation Construction Work in Progress KU December 31, 2017 Generating Plants E.W. Brown Units 6-7 62.00 % $ 66 $ 27 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 46 13 — Trimble County Unit 2 60.75 % 817 140 96 Trimble County Units 5-6 71.00 % 76 20 — Trimble County Units 7-10 63.00 % 120 34 — Cane Run Unit 7 78.00 % 431 31 4 E.W. Brown Solar Unit 61.00 % 16 1 — December 31, 2016 Generating Plants E.W. Brown Units 6-7 62.00 % $ 65 $ 23 $ — Paddy's Run Unit 13 & E.W. Brown Unit 5 47.00 % 50 11 1 Trimble County Unit 2 60.75 % 812 129 40 Trimble County Units 5-6 71.00 % 74 19 — Trimble County Units 7-10 63.00 % 121 29 1 Cane Run Unit 7 78.00 % 412 18 4 E.W. Brown Solar Unit 61.00 % 15 — —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligations	LG&E and KU enter into purchase contracts to supply the coal and natural gas requirements for generation facilities and LG&E's retail natural gas supply operations. These contracts include the following commitments: Contract Type Maximum Maturity Date Natural Gas Fuel 2019 Natural Gas Retail Supply 2019 Coal 2023 Coal Transportation and Fleeting Services 2024 Natural Gas Transportation 2026 Future obligations for power purchases from OVEC are unconditional demand payments, comprised of debt-service payments and contractually-required reimbursements of plant operating, maintenance and other expenses, and are projected as follows: LG&E KU Total 2018 $ 20 $ 9 $ 29 2019 19 8 27 2020 18 8 26 2021 19 8 27 2022 19 8 27 Thereafter 316 141 457 Total $ 411 $ 182 $ 593 LG&E and KU had total energy purchases under the OVEC power purchase agreement for the years ended December 31 as follows: 2017 2016 2015 LG&E $ 14 $ 16 $ 15 KU 6 7 7 Total $ 20 $ 23 $ 22
Guarantees	The table below details guarantees provided as of December 31, 2017 . Exposure at Expiration Date PPL Indemnifications related to the WPD Midlands acquisition (a) WPD indemnifications for entities in liquidation and sales of assets $ 11 (b) 2020 WPD guarantee of pension and other obligations of unconsolidated entities 95 (c) PPL Electric Guarantee of inventory value 16 (d) 2018 LKE Indemnification of lease termination and other divestitures 201 (e) 2021-2023 LG&E and KU LG&E and KU guarantee of shortfall related to OVEC (f) (a) Indemnifications related to certain liabilities, including a specific unresolved tax issue and those relating to properties and assets owned by the seller that were transferred to WPD Midlands in connection with the acquisition. A cross indemnity has been received from the seller on the tax issue. The maximum exposure and expiration of these indemnifications cannot be estimated because the maximum potential liability is not capped and the expiration date is not specified in the transaction documents. (b) Indemnification to the liquidators and certain others for existing liabilities or expenses or liabilities arising during the liquidation process. The indemnifications are limited to distributions made from the subsidiary to its parent either prior or subsequent to liquidation or are not explicitly stated in the agreements. The indemnifications generally expire two to seven years subsequent to the date of dissolution of the entities. The exposure noted only includes those cases where the agreements provide for specific limits. In connection with their sales of various businesses, WPD and its affiliates have provided the purchasers with indemnifications that are standard for such transactions, including indemnifications for certain pre-existing liabilities and environmental and tax matters or have agreed to continue their obligations under existing third-party guarantees, either for a set period of time following the transactions or upon the condition that the purchasers make reasonable efforts to terminate the guarantees. Additionally, WPD and its affiliates remain secondarily responsible for lease payments under certain leases that they have assigned to third parties. (c) Relates to certain obligations of discontinued or modified electric associations that were guaranteed at the time of privatization by the participating members. Costs are allocated to the members and can be reallocated if an existing member becomes insolvent. At December 31, 2017 , WPD has recorded an estimated discounted liability for which the expected payment/performance is probable. Neither the expiration date nor the maximum amount of potential payments for certain obligations is explicitly stated in the related agreements, and as a result, the exposure has been estimated. (d) A third party logistics firm provides inventory procurement and fulfillment services. The logistics firm has title to the inventory, however, upon termination of the contracts, PPL Electric has guaranteed to purchase any remaining inventory that has not been used or sold. In January 2018, this agreement was superseded by a new contract which extends the guarantee until 2020. (e) LKE provides certain indemnifications covering the due and punctual payment, performance and discharge by each party of its respective obligations. The most comprehensive of these guarantees is the LKE guarantee covering operational, regulatory and environmental commitments and indemnifications made by WKE under a 2009 Transaction Termination Agreement. This guarantee has a term of 12 years ending July 2021, and a maximum exposure of $200 million , exclusive of certain items such as government fines and penalties that may exceed the maximum. Another WKE-related LKE guarantee formerly covered other indemnifications related to the purchase price of excess power, had a term expiring in 2023, and a maximum exposure of $100 million which excess power matter and related indemnifications had been the subject of a dispute and legal proceeding among the parties. In December 2017, the parties executed settlement agreements which resolved all claims relating to the excess power matter, and terminated such guarantee, for $11 million . Additionally, LKE has indemnified various third parties related to historical obligations for other divested subsidiaries and affiliates. The indemnifications vary by entity and the maximum exposures range from being capped at the sale price to no specified maximum. LKE could be required to perform on these indemnifications in the event of covered losses or liabilities being claimed by an indemnified party. LKE cannot predict the ultimate outcomes of the various indemnification scenarios, but does not expect such outcomes to result in significant losses above the amounts recorded. (f) Pursuant to the OVEC power purchase contract, LG&E and KU are obligated to pay for their share of OVEC's excess debt service, post-retirement and decommissioning costs, as well as any shortfall from amounts included within a demand charge designed and expected to cover these costs over the term of the contract. LKE's proportionate share of OVEC's outstanding debt was $117 million at December 31, 2017 , consisting of LG&E's share of $81 million and KU's share of $36 million . The maximum exposure and the expiration date of these potential obligations are not presently determinable. See "Energy Purchase Commitments" above for additional information on the OVEC power purchase contract. In connection with recent credit market related developments at OVEC or certain of its sponsors, such parties, including LG&E and KU, have allowed implementation of a limited, partial OVEC reserve fund for debt costs and are analyzing certain potential additional credit support actions to preserve OVEC's access to credit markets or mitigate risks or adverse impacts relating thereto, including increased interest costs and accelerated maturities of OVEC's existing short and long-term debt. The ultimate outcome of these matters, including any potential impact on LG&E's and KU's obligations relating to OVEC debt under the power purchase contract cannot be predicted.
LG And E And KU Energy LLC [Member]
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligations	LG&E and KU enter into purchase contracts to supply the coal and natural gas requirements for generation facilities and LG&E's retail natural gas supply operations. These contracts include the following commitments: Contract Type Maximum Maturity Date Natural Gas Fuel 2019 Natural Gas Retail Supply 2019 Coal 2023 Coal Transportation and Fleeting Services 2024 Natural Gas Transportation 2026 Future obligations for power purchases from OVEC are unconditional demand payments, comprised of debt-service payments and contractually-required reimbursements of plant operating, maintenance and other expenses, and are projected as follows: LG&E KU Total 2018 $ 20 $ 9 $ 29 2019 19 8 27 2020 18 8 26 2021 19 8 27 2022 19 8 27 Thereafter 316 141 457 Total $ 411 $ 182 $ 593 LG&E and KU had total energy purchases under the OVEC power purchase agreement for the years ended December 31 as follows: 2017 2016 2015 LG&E $ 14 $ 16 $ 15 KU 6 7 7 Total $ 20 $ 23 $ 22
Louisville Gas And Electric Co [Member]
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligations	Future obligations for power purchases from OVEC are unconditional demand payments, comprised of debt-service payments and contractually-required reimbursements of plant operating, maintenance and other expenses, and are projected as follows: LG&E KU Total 2018 $ 20 $ 9 $ 29 2019 19 8 27 2020 18 8 26 2021 19 8 27 2022 19 8 27 Thereafter 316 141 457 Total $ 411 $ 182 $ 593 LG&E and KU had total energy purchases under the OVEC power purchase agreement for the years ended December 31 as follows: 2017 2016 2015 LG&E $ 14 $ 16 $ 15 KU 6 7 7 Total $ 20 $ 23 $ 22 LG&E and KU enter into purchase contracts to supply the coal and natural gas requirements for generation facilities and LG&E's retail natural gas supply operations. These contracts include the following commitments: Contract Type Maximum Maturity Date Natural Gas Fuel 2019 Natural Gas Retail Supply 2019 Coal 2023 Coal Transportation and Fleeting Services 2024 Natural Gas Transportation 2026
Kentucky Utilities Co [Member]
Commitments And Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligations	LG&E and KU enter into purchase contracts to supply the coal and natural gas requirements for generation facilities and LG&E's retail natural gas supply operations. These contracts include the following commitments: Contract Type Maximum Maturity Date Natural Gas Fuel 2019 Natural Gas Retail Supply 2019 Coal 2023 Coal Transportation and Fleeting Services 2024 Natural Gas Transportation 2026 Future obligations for power purchases from OVEC are unconditional demand payments, comprised of debt-service payments and contractually-required reimbursements of plant operating, maintenance and other expenses, and are projected as follows: LG&E KU Total 2018 $ 20 $ 9 $ 29 2019 19 8 27 2020 18 8 26 2021 19 8 27 2022 19 8 27 Thereafter 316 141 457 Total $ 411 $ 182 $ 593 LG&E and KU had total energy purchases under the OVEC power purchase agreement for the years ended December 31 as follows: 2017 2016 2015 LG&E $ 14 $ 16 $ 15 KU 6 7 7 Total $ 20 $ 23 $ 22

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2017
PPL Electric Utilities Corp [Member]
Related Party Transactions [Line Items]
Intercompany Support Cost Allocations	PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185
LG And E And KU Energy LLC [Member]
Related Party Transactions [Line Items]
Intercompany Support Cost Allocations	PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185
Louisville Gas And Electric Co [Member]
Related Party Transactions [Line Items]
Intercompany Support Cost Allocations	PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185
Kentucky Utilities Co [Member]
Related Party Transactions [Line Items]
Intercompany Support Cost Allocations	PPL Services, PPL EU Services and LKS charged the following amounts for the years ended December 31, including amounts applied to accounts that are further distributed between capital and expense on the books of the recipients, based on methods that are believed to be reasonable. 2017 2016 2015 PPL Electric from PPL Services $ 182 $ 132 $ 125 LKE from PPL Services 20 18 16 PPL Electric from PPL EU Services 64 69 60 LG&E from LKS 169 178 155 KU from LKS 190 194 185

Other Income (Expense) - net (T

Other Income (Expense) - net (Tables)	12 Months Ended
	Dec. 31, 2017
Other Income (Expense) Net [Line Items]
Other Income (Expense) - net	The breakdown of "Other Income (Expense) - net" for the years ended December 31, was: 2017 2016 2015 Other Income Economic foreign currency exchange contracts (Note 17) $ (261 ) $ 384 $ 122 Interest income 2 3 4 AFUDC - equity component 16 19 14 Miscellaneous 17 6 6 Total Other Income (226 ) 412 146 Other Expense Charitable contributions 8 9 21 Miscellaneous 21 13 17 Total Other Expense 29 22 38 Other Income (Expense) - net $ (255 ) $ 390 $ 108

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value [Line Items]
Fair Value of Assets and Liabilities Measured on Recurring Basis	The assets and liabilities measured at fair value were: December 31, 2017 December 31, 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 PPL Assets Cash and cash equivalents $ 485 $ 485 $ — $ — $ 341 $ 341 $ — $ — Restricted cash and cash equivalents (a) 26 26 — — 26 26 — — Price risk management assets (b): Foreign currency contracts 163 — 163 — 211 — 211 — Cross-currency swaps 101 — 101 — 188 — 188 — Total price risk management assets 264 — 264 — 399 — 399 — Total assets $ 775 $ 511 $ 264 $ — $ 766 $ 367 $ 399 $ — December 31, 2017 December 31, 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Liabilities Price risk management liabilities (b): Interest rate swaps $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — Foreign currency contracts 148 — 148 — 27 — 27 — Total price risk management liabilities $ 174 $ — $ 174 $ — $ 58 $ — $ 58 $ — PPL Electric Assets Cash and cash equivalents $ 49 $ 49 $ — $ — $ 13 $ 13 $ — $ — Restricted cash and cash equivalents (a) 2 2 — — 2 2 — — Total assets $ 51 $ 51 $ — $ — $ 15 $ 15 $ — $ — LKE Assets Cash and cash equivalents $ 30 $ 30 $ — $ — $ 13 $ 13 $ — $ — Cash collateral posted to counterparties (c) — — — — 3 3 — — Total assets $ 30 $ 30 $ — $ — $ 16 $ 16 $ — $ — Liabilities Price risk management liabilities: Interest rate swaps $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — Total price risk management liabilities $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — LG&E Assets Cash and cash equivalents $ 15 $ 15 $ — $ — $ 5 $ 5 $ — $ — Cash collateral posted to counterparties (c) — — — — 3 3 — — Total assets $ 15 $ 15 $ — $ — $ 8 $ 8 $ — $ — Liabilities Price risk management liabilities: Interest rate swaps $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — Total price risk management liabilities $ 26 $ — $ 26 $ — $ 31 $ — $ 31 $ — KU Assets Cash and cash equivalents $ 15 $ 15 $ — $ — $ 7 $ 7 $ — $ — Total assets $ 15 $ 15 $ — $ — $ 7 $ 7 $ — $ — (a) Current portion is included in "Other current assets" and long-term portion is included in "Other noncurrent assets" on the Balance Sheets. (b) Current portion is included in "Price risk management assets" and "Other current liabilities" and noncurrent portion is included in "Price risk management assets" and "Other deferred credits and noncurrent liabilities" on the Balance Sheets. (c) Included in "Other noncurrent assets" on the Balance Sheets. Represents cash collateral posted to offset the exposure with counterparties related to certain interest rate swaps under master netting arrangements that are not offset.
Fair Value of Financial Instruments Not Recorded at Fair Value - Other	The carrying amounts of long-term debt on the Balance Sheets and their estimated fair values are set forth below. December 31, 2017 December 31, 2016 Carrying Fair Value Carrying Fair Value PPL $ 20,195 $ 23,783 $ 18,326 $ 21,355 PPL Electric 3,298 3,769 2,831 3,148 LKE 5,159 5,670 5,065 5,439 LG&E 1,709 1,865 1,617 1,710 KU 2,328 2,605 2,327 2,514

Derivative Instruments and He51

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments And Hedging Activities [Line Items]
Fair Value and Balance Sheet Location of Derivative Instruments	The following table presents the fair value and location of derivative instruments recorded on the Balance Sheets. December 31, 2017 December 31, 2016 Derivatives designated as hedging instruments Derivatives not designated as hedging instruments Derivatives designated as hedging instruments Derivatives not designated as hedging instruments Assets Liabilities Assets Liabilities Assets Liabilities Assets Liabilities Current: Price Risk Management Assets/Liabilities (a): Interest rate swaps (b) $ — $ — $ — $ 4 $ — $ — $ — $ 4 Cross-currency swaps (b) 4 — — — 32 — — — Foreign currency contracts — — 45 67 — — 31 21 Total current 4 — 45 71 32 — 31 25 Noncurrent: Price Risk Management Assets/Liabilities (a): Interest rate swaps (b) — — — 22 — — — 27 Cross-currency swaps (b) 97 — — — 156 — — — Foreign currency contracts — — 118 81 — — 180 6 Total noncurrent 97 — 118 103 156 — 180 33 Total derivatives $ 101 $ — $ 163 $ 174 $ 188 $ — $ 211 $ 58 (a) Current portion is included in "Price risk management assets" and "Other current liabilities" and noncurrent portion is included in "Price risk management assets" and "Other deferred credits and noncurrent liabilities" on the Balance Sheets. (b) Excludes accrued interest, if applicable.
Pre-tax Gain (Loss) on Derivative Instruments Recognized in Income or on the Balance Sheet	The following tables present the pre-tax effect of derivative instruments recognized in income, OCI or regulatory assets and regulatory liabilities. Derivative Relationships Derivative Gain (Loss) Recognized in OCI (Effective Portion) Location of Gain (Loss) Recognized in Income on Derivative Gain (Loss) Reclassified from AOCI into Income (Effective Portion) Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) 2017 Cash Flow Hedges: Interest rate swaps $ — Interest Expense $ (9 ) $ — Cross-currency swaps (98 ) Other Income (Expense) - net (82 ) — Total $ (98 ) $ (91 ) $ — Net Investment Hedges: Foreign currency contracts $ 1 2016 Cash Flow Hedges: Interest rate swaps $ (21 ) Interest Expense $ (7 ) $ — Cross-currency swaps 130 Other Income (Expense) - net 116 — Interest Expense 3 — Total $ 109 $ 112 $ — Net Investment Hedges: Foreign currency contracts $ 2 Derivative Relationships Derivative Gain (Loss) Recognized in OCI (Effective Portion) Location of Gain (Loss) Recognized in Income on Derivative Gain (Loss) Reclassified from AOCI into Income (Effective Portion) Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) 2015 Cash Flow Hedges: Interest rate swaps $ (34 ) Interest Expense $ (11 ) $ — Discontinued operations — (77 ) Cross-currency swaps 60 Other Income (Expense) - net 49 — Interest Expense 2 — Commodity contracts Discontinued operations 13 7 Total $ 26 $ 53 $ (70 ) Net Investment Hedges: Foreign currency contracts $ 9 Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative 2017 2016 2015 Foreign currency contracts Other Income (Expense) - net $ (261 ) $ 384 $ 122 Interest rate swaps Interest Expense (6 ) (7 ) (8 ) Total $ (267 ) $ 377 $ 114 Derivatives Designated as Hedging Instruments Location of Gain (Loss) Recognized as Regulatory Liabilities/Assets 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ — $ — $ (22 ) Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized as Regulatory Liabilities/Assets 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ 5 $ 7 $ 1
Derivative Positions Eligible for Offset with Related Cash Collateral	The table below summarizes the derivative positions presented in the balance sheets where a right of setoff exists under these arrangements and related cash collateral received or pledged. Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2017 Treasury Derivatives PPL $ 264 $ 107 $ 20 $ 137 $ 174 $ 107 $ — $ 67 LKE — — — — 26 — — 26 LG&E — — — — 26 — — 26 Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2016 Treasury Derivatives PPL $ 399 $ 27 $ 19 $ 353 $ 58 $ 27 $ 3 $ 28 LKE — — — — 31 — 3 28 LG&E — — — — 31 — 3 28
Credit Risk-Related Contingent Features	At December 31, 2017 , derivative contracts in a net liability position that contain credit risk-related contingent features, collateral posted on those positions and the related effect of a decrease in credit ratings below investment grade are summarized as follows: PPL LKE LG&E Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features $ 51 $ 10 $ 10 Aggregate fair value of collateral posted on these derivative instruments — — — Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade (a) 51 10 10 (a) Includes the effect of net receivables and payables already recorded on the Balance Sheet.
LG And E And KU Energy LLC [Member]
Derivative Instruments And Hedging Activities [Line Items]
Fair Value and Balance Sheet Location of Derivative Instruments	The following table presents the fair value and the location on the Balance Sheets of derivatives not designated as hedging instruments. December 31, 2017 December 31, 2016 Assets Liabilities Assets Liabilities Current: Price Risk Management Assets/Liabilities: Interest rate swaps $ — $ 4 $ — $ 4 Total current — 4 — 4 Noncurrent: Price Risk Management Assets/Liabilities: Interest rate swaps — 22 — 27 Total noncurrent — 22 — 27 Total derivatives $ — $ 26 $ — $ 31
Pre-tax Gain (Loss) on Derivative Instruments Recognized in Income or on the Balance Sheet	The following tables present the pre-tax effect of derivatives not designated as cash flow hedges that are recognized in income or regulatory assets. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Interest Expense $ (6 ) $ (7 ) $ (8 ) Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ 5 $ 7 $ 1 The following table presents the pre-tax effect of derivative instruments designated as cash flow hedges that are recognized in regulatory assets. All derivative instruments designated as cash flow hedges were terminated in 2015 and there is no activity in the current period. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ — $ — $ (22 )
Derivative Positions Eligible for Offset with Related Cash Collateral	The table below summarizes the derivative positions presented in the balance sheets where a right of setoff exists under these arrangements and related cash collateral received or pledged. Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2017 Treasury Derivatives PPL $ 264 $ 107 $ 20 $ 137 $ 174 $ 107 $ — $ 67 LKE — — — — 26 — — 26 LG&E — — — — 26 — — 26 Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2016 Treasury Derivatives PPL $ 399 $ 27 $ 19 $ 353 $ 58 $ 27 $ 3 $ 28 LKE — — — — 31 — 3 28 LG&E — — — — 31 — 3 28
Credit Risk-Related Contingent Features	At December 31, 2017 , derivative contracts in a net liability position that contain credit risk-related contingent features, collateral posted on those positions and the related effect of a decrease in credit ratings below investment grade are summarized as follows: PPL LKE LG&E Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features $ 51 $ 10 $ 10 Aggregate fair value of collateral posted on these derivative instruments — — — Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade (a) 51 10 10 (a) Includes the effect of net receivables and payables already recorded on the Balance Sheet.
Louisville Gas And Electric Co [Member]
Derivative Instruments And Hedging Activities [Line Items]
Fair Value and Balance Sheet Location of Derivative Instruments	The following table presents the fair value and the location on the Balance Sheets of derivatives not designated as hedging instruments. December 31, 2017 December 31, 2016 Assets Liabilities Assets Liabilities Current: Price Risk Management Assets/Liabilities: Interest rate swaps $ — $ 4 $ — $ 4 Total current — 4 — 4 Noncurrent: Price Risk Management Assets/Liabilities: Interest rate swaps — 22 — 27 Total noncurrent — 22 — 27 Total derivatives $ — $ 26 $ — $ 31
Pre-tax Gain (Loss) on Derivative Instruments Recognized in Income or on the Balance Sheet	The following tables present the pre-tax effect of derivatives not designated as cash flow hedges that are recognized in income or regulatory assets. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Interest Expense $ (6 ) $ (7 ) $ (8 ) Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ 5 $ 7 $ 1 The following table presents the pre-tax effect of derivative instruments designated as cash flow hedges that are recognized in regulatory assets. All derivative instruments designated as cash flow hedges were terminated in 2015 and there is no activity in the current period. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory asset - noncurrent $ — $ — $ (11 )
Derivative Positions Eligible for Offset with Related Cash Collateral	The table below summarizes the derivative positions presented in the balance sheets where a right of setoff exists under these arrangements and related cash collateral received or pledged. Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2017 Treasury Derivatives PPL $ 264 $ 107 $ 20 $ 137 $ 174 $ 107 $ — $ 67 LKE — — — — 26 — — 26 LG&E — — — — 26 — — 26 Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2016 Treasury Derivatives PPL $ 399 $ 27 $ 19 $ 353 $ 58 $ 27 $ 3 $ 28 LKE — — — — 31 — 3 28 LG&E — — — — 31 — 3 28
Credit Risk-Related Contingent Features	At December 31, 2017 , derivative contracts in a net liability position that contain credit risk-related contingent features, collateral posted on those positions and the related effect of a decrease in credit ratings below investment grade are summarized as follows: PPL LKE LG&E Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features $ 51 $ 10 $ 10 Aggregate fair value of collateral posted on these derivative instruments — — — Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade (a) 51 10 10 (a) Includes the effect of net receivables and payables already recorded on the Balance Sheet.
Kentucky Utilities Co [Member]
Derivative Instruments And Hedging Activities [Line Items]
Pre-tax Gain (Loss) on Derivative Instruments Recognized in Income or on the Balance Sheet	The following table presents the pre-tax effect of derivative instruments designated as cash flow hedges that are recognized in regulatory assets. All derivative instruments designated as cash flow hedges were terminated in 2015 and there is no activity in the current period. Derivative Instruments Location of Gain (Loss) 2017 2016 2015 Interest rate swaps Regulatory assets - noncurrent $ — $ — $ (11 )
Derivative Positions Eligible for Offset with Related Cash Collateral	The table below summarizes the derivative positions presented in the balance sheets where a right of setoff exists under these arrangements and related cash collateral received or pledged. Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2017 Treasury Derivatives PPL $ 264 $ 107 $ 20 $ 137 $ 174 $ 107 $ — $ 67 LKE — — — — 26 — — 26 LG&E — — — — 26 — — 26 Assets Liabilities Eligible for Offset Eligible for Offset Gross Derivative Instruments Cash Collateral Received Net Gross Derivative Instruments Cash Collateral Pledged Net December 31, 2016 Treasury Derivatives PPL $ 399 $ 27 $ 19 $ 353 $ 58 $ 27 $ 3 $ 28 LKE — — — — 31 — 3 28 LG&E — — — — 31 — 3 28

Goodwill and Other Intangible52

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Intangible Assets [Line Items]
Goodwill Rollforward	The changes in the carrying amount of goodwill by segment were: U.K. Regulated Kentucky Regulated Total 2017 2016 2017 2016 2017 2016 Balance at beginning of period (a) $ 2,398 $ 2,888 $ 662 $ 662 $ 3,060 $ 3,550 Effect of foreign currency exchange rates 198 (490 ) 198 (490 ) Balance at end of period (a) $ 2,596 $ 2,398 $ 662 $ 662 $ 3,258 $ 3,060 (a) There were no accumulated impairment losses related to goodwill.
Other Intangible Assets	The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Contracts (a) $ 138 $ 67 $ 405 $ 325 Land and transmission rights 382 120 362 115 Emission allowances/RECs (b) 1 — 2 — Licenses and other 7 3 6 2 Total subject to amortization 528 190 775 442 Not subject to amortization due to indefinite life: Land and transmission rights 12 — 19 — Easements 347 — 348 — Total not subject to amortization due to indefinite life 359 — 367 — Total $ 887 $ 190 $ 1,142 $ 442 (a) Gross carrying amount in 2017 and 2016 includes the fair value at the acquisition date of the OVEC power purchase contract with terms favorable to market recognized as a result of the 2010 acquisition of LKE by PPL. Gross carrying amount in 2016 also includes the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition of LKE by PPL. At December 31, 2016, these coal contracts were fully amortized. Offsetting regulatory liabilities were recorded related to these contracts, which are being amortized over the same period as the intangible assets, eliminating any income statement impact. This is referred to as "regulatory offset" in the tables below. See Note 6 for additional information. (b) Emission allowances/RECs are expensed when consumed or sold; therefore, there is no accumulated amortization.
Amortization Expense, Excluding Consumption of Emission Allowances / Renewable Energy Credits	Amortization Expense was as follows: 2017 2016 2015 Intangible assets with no regulatory offset $ 6 $ 6 $ 6 Intangible assets with regulatory offset 9 24 51 Total $ 15 $ 30 $ 57
Future Amortization Expense	Amortization expense for each of the next five years, excluding insignificant amounts for consumption of emission allowances/RECs, is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with no regulatory offset $ 6 $ 6 $ 6 $ 6 $ 6 Intangible assets with regulatory offset 9 9 8 8 8 Total $ 15 $ 15 $ 14 $ 14 $ 14
PPL Electric Utilities Corp [Member]
Goodwill and Other Intangible Assets [Line Items]
Other Intangible Assets	The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Land and transmission rights $ 361 $ 117 $ 341 $ 112 Licenses and other 3 1 3 1 Total subject to amortization 364 118 344 113 Not subject to amortization due to indefinite life: Land and transmission rights 13 — 20 — Total $ 377 $ 118 $ 364 $ 113
LG And E And KU Energy LLC [Member]
Goodwill and Other Intangible Assets [Line Items]
Other Intangible Assets	The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Coal contracts (a) $ — $ — $ 269 $ 269 Land and transmission rights 21 3 21 3 OVEC power purchase agreement (b) 126 58 126 49 Total subject to amortization $ 147 $ 61 $ 416 $ 321 (a) Gross carrying amount represents the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to these contracts, which was amortized over the same period as the intangible asset, eliminating any income statement impact. (b) Gross carrying amount represents the fair value at the acquisition date of the OVEC power purchase contract recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to this contract, which is being amortized over the same period as the intangible asset, eliminating any income statement impact. See Note 6 for additional information.
Amortization Expense, Excluding Consumption of Emission Allowances / Renewable Energy Credits	Amortization expense was as follows: 2017 2016 2015 Intangible assets with no regulatory offset $ — $ 1 $ — Intangible assets with regulatory offset 9 24 51 Total $ 9 $ 25 $ 51
Future Amortization Expense	Amortization expense for each of the next five years is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with regulatory offset $ 9 $ 9 $ 8 $ 8 $ 8
Louisville Gas And Electric Co [Member]
Goodwill and Other Intangible Assets [Line Items]
Other Intangible Assets	The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Coal contracts (a) $ — $ — $ 124 $ 124 Land and transmission rights 7 1 7 1 OVEC power purchase agreement (b) 87 40 87 34 Total subject to amortization $ 94 $ 41 $ 218 $ 159 (a) Gross carrying amount represents the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to these contracts, which was amortized over the same period as the intangible asset, eliminating any income statement impact. (b) Gross carrying amount represents the fair value at the acquisition date of the OVEC power purchase contract recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to this contract, which is being amortized over the same period as the intangible asset, eliminating any income statement impact. See Note 6 for additional information.
Amortization Expense, Excluding Consumption of Emission Allowances / Renewable Energy Credits	Amortization expense was as follows: 2017 2016 2015 Intangible assets with regulatory offset $ 6 $ 13 $ 24
Future Amortization Expense	Amortization expense for each of the next five years is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with regulatory offset $ 6 $ 6 $ 6 $ 6 $ 6
Kentucky Utilities Co [Member]
Goodwill and Other Intangible Assets [Line Items]
Other Intangible Assets	The gross carrying amount and the accumulated amortization of other intangible assets were: December 31, 2017 December 31, 2016 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Subject to amortization: Coal contracts (a) $ — $ — $ 145 $ 145 Land and transmission rights 14 2 14 2 OVEC power purchase agreement (b) 39 18 39 15 Total subject to amortization $ 53 $ 20 $ 198 $ 162 (a) Gross carrying amount represents the fair value at the acquisition date of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to these contracts, which was amortized over the same period as the intangible asset, eliminating any income statement impact. (b) Gross carrying amount represents the fair value at the acquisition date of the OVEC power purchase contract recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to this contract, which is being amortized over the same period as the intangible asset, eliminating any income statement impact. See Note 6 for additional information.
Amortization Expense, Excluding Consumption of Emission Allowances / Renewable Energy Credits	Amortization expense was as follows: 2017 2016 2015 Intangible assets with no regulatory offset $ — $ 1 $ — Intangible assets with regulatory offset 3 11 27 Total $ 3 $ 12 $ 27
Future Amortization Expense	Amortization expense for each of the next five years is estimated to be: 2018 2019 2020 2021 2022 Intangible assets with regulatory offset $ 3 $ 3 $ 2 $ 2 $ 2

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation Roll Forward	The changes in the carrying amounts of AROs were as follows: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 ARO at beginning of period $ 488 $ 586 $ 433 $ 535 $ 145 $ 175 $ 288 $ 360 Accretion 21 24 20 22 7 7 13 15 Changes in estimated timing or cost (a) (73 ) (84 ) (54 ) (95 ) (8 ) (19 ) (46 ) (76 ) Effect of foreign currency exchange rates 4 (9 ) — — — — — — Obligations settled (43 ) (29 ) (43 ) (29 ) (23 ) (18 ) (20 ) (11 ) ARO at end of period $ 397 $ 488 $ 356 $ 433 $ 121 $ 145 $ 235 $ 288
LG And E And KU Energy LLC [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation Roll Forward	The changes in the carrying amounts of AROs were as follows: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 ARO at beginning of period $ 488 $ 586 $ 433 $ 535 $ 145 $ 175 $ 288 $ 360 Accretion 21 24 20 22 7 7 13 15 Changes in estimated timing or cost (a) (73 ) (84 ) (54 ) (95 ) (8 ) (19 ) (46 ) (76 ) Effect of foreign currency exchange rates 4 (9 ) — — — — — — Obligations settled (43 ) (29 ) (43 ) (29 ) (23 ) (18 ) (20 ) (11 ) ARO at end of period $ 397 $ 488 $ 356 $ 433 $ 121 $ 145 $ 235 $ 288
Louisville Gas And Electric Co [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation Roll Forward	The changes in the carrying amounts of AROs were as follows: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 ARO at beginning of period $ 488 $ 586 $ 433 $ 535 $ 145 $ 175 $ 288 $ 360 Accretion 21 24 20 22 7 7 13 15 Changes in estimated timing or cost (a) (73 ) (84 ) (54 ) (95 ) (8 ) (19 ) (46 ) (76 ) Effect of foreign currency exchange rates 4 (9 ) — — — — — — Obligations settled (43 ) (29 ) (43 ) (29 ) (23 ) (18 ) (20 ) (11 ) ARO at end of period $ 397 $ 488 $ 356 $ 433 $ 121 $ 145 $ 235 $ 288
Kentucky Utilities Co [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation Roll Forward	The changes in the carrying amounts of AROs were as follows: PPL LKE LG&E KU 2017 2016 2017 2016 2017 2016 2017 2016 ARO at beginning of period $ 488 $ 586 $ 433 $ 535 $ 145 $ 175 $ 288 $ 360 Accretion 21 24 20 22 7 7 13 15 Changes in estimated timing or cost (a) (73 ) (84 ) (54 ) (95 ) (8 ) (19 ) (46 ) (76 ) Effect of foreign currency exchange rates 4 (9 ) — — — — — — Obligations settled (43 ) (29 ) (43 ) (29 ) (23 ) (18 ) (20 ) (11 ) ARO at end of period $ 397 $ 488 $ 356 $ 433 $ 121 $ 145 $ 235 $ 288

Accumulated Other Comprehensi54

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss)	The after-tax changes in AOCI by component for the years ended December 31 were as follows: Unrealized gains (losses) Defined benefit plans Foreign currency translation adjustments Available- for-sale securities Qualifying derivatives Equity investees' AOCI Prior service costs Actuarial gain (loss) Total PPL December 31, 2014 $ (286 ) $ 201 $ 20 $ 1 $ 3 $ (2,213 ) $ (2,274 ) Amounts arising during the year (234 ) 8 26 — (9 ) (366 ) (575 ) Reclassifications from AOCI — (2 ) 2 (1 ) — 146 145 Net OCI during the year (234 ) 6 28 (1 ) (9 ) (220 ) (430 ) Distribution of PPL Energy — (207 ) (55 ) — — 238 (24 ) December 31, 2015 $ (520 ) $ — $ (7 ) $ — $ (6 ) $ (2,195 ) $ (2,728 ) Amounts arising during the year (1,107 ) — 91 — (3 ) (61 ) (1,080 ) Reclassifications from AOCI — — (91 ) (1 ) 1 121 30 Net OCI during the year (1,107 ) — — (1 ) (2 ) 60 (1,050 ) December 31, 2016 $ (1,627 ) $ — $ (7 ) $ (1 ) $ (8 ) $ (2,135 ) $ (3,778 ) Amounts arising during the year 538 — (79 ) — — (308 ) 151 Reclassifications from AOCI — — 73 1 1 130 205 Net OCI during the year 538 — (6 ) 1 1 (178 ) 356 December 31, 2017 $ (1,089 ) $ — $ (13 ) $ — $ (7 ) $ (2,313 ) $ (3,422 ) LKE December 31, 2014 $ — $ (8 ) $ (37 ) $ (45 ) Amounts arising during the year — (3 ) (4 ) (7 ) Reclassifications from AOCI — 1 5 6 Net OCI during the year — (2 ) 1 (1 ) December 31, 2015 $ — $ (10 ) $ (36 ) $ (46 ) Amounts arising during the year — — (27 ) (27 ) Reclassifications from AOCI (1 ) 2 2 3 Net OCI during the year (1 ) 2 (25 ) (24 ) December 31, 2016 $ (1 ) $ (8 ) $ (61 ) $ (70 ) Amounts arising during the year — (2 ) (23 ) (25 ) Reclassifications from AOCI 1 1 5 7 Net OCI during the year 1 (1 ) (18 ) (18 ) December 31, 2017 $ — $ (9 ) $ (79 ) $ (88 )
Reclassification out of Other Comprehensive Income (Loss)	The following table presents PPL's gains (losses) and related income taxes for reclassifications from AOCI for the years ended December 31, 2017 , 2016 and 2015 . PPL Details about AOCI 2017 2016 2015 Affected Line Item on the Available-for-sale securities $ — $ — $ 4 Other Income (Expense) - net Total Pre-tax — — 4 Income Taxes — — (2 ) Total After-tax — — 2 Qualifying derivatives Interest rate swaps (9 ) (7 ) (11 ) Interest Expense — — (77 ) Discontinued operations Cross-currency swaps (82 ) 116 49 Other Income (Expense) - net — 3 2 Interest Expense Commodity contracts — — 20 Discontinued operations Total Pre-tax (91 ) 112 (17 ) Income Taxes 18 (21 ) 15 Total After-tax (73 ) 91 (2 ) Equity Investees' AOCI (1 ) 1 1 Other Income (Expense) - net Total Pre-tax (1 ) 1 1 Income Taxes — — — Total After-tax (1 ) 1 1 Defined benefit plans Prior service costs (2 ) (2 ) — Net actuarial loss (167 ) (156 ) (192 ) Total Pre-tax (169 ) (158 ) (192 ) Income Taxes 38 36 46 Total After-tax (131 ) (122 ) (146 ) Total reclassifications during the year $ (205 ) $ (30 ) $ (145 )
LG And E And KU Energy LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss)	The after-tax changes in AOCI by component for the years ended December 31 were as follows: Unrealized gains (losses) Defined benefit plans Foreign currency translation adjustments Available- for-sale securities Qualifying derivatives Equity investees' AOCI Prior service costs Actuarial gain (loss) Total PPL December 31, 2014 $ (286 ) $ 201 $ 20 $ 1 $ 3 $ (2,213 ) $ (2,274 ) Amounts arising during the year (234 ) 8 26 — (9 ) (366 ) (575 ) Reclassifications from AOCI — (2 ) 2 (1 ) — 146 145 Net OCI during the year (234 ) 6 28 (1 ) (9 ) (220 ) (430 ) Distribution of PPL Energy — (207 ) (55 ) — — 238 (24 ) December 31, 2015 $ (520 ) $ — $ (7 ) $ — $ (6 ) $ (2,195 ) $ (2,728 ) Amounts arising during the year (1,107 ) — 91 — (3 ) (61 ) (1,080 ) Reclassifications from AOCI — — (91 ) (1 ) 1 121 30 Net OCI during the year (1,107 ) — — (1 ) (2 ) 60 (1,050 ) December 31, 2016 $ (1,627 ) $ — $ (7 ) $ (1 ) $ (8 ) $ (2,135 ) $ (3,778 ) Amounts arising during the year 538 — (79 ) — — (308 ) 151 Reclassifications from AOCI — — 73 1 1 130 205 Net OCI during the year 538 — (6 ) 1 1 (178 ) 356 December 31, 2017 $ (1,089 ) $ — $ (13 ) $ — $ (7 ) $ (2,313 ) $ (3,422 ) LKE December 31, 2014 $ — $ (8 ) $ (37 ) $ (45 ) Amounts arising during the year — (3 ) (4 ) (7 ) Reclassifications from AOCI — 1 5 6 Net OCI during the year — (2 ) 1 (1 ) December 31, 2015 $ — $ (10 ) $ (36 ) $ (46 ) Amounts arising during the year — — (27 ) (27 ) Reclassifications from AOCI (1 ) 2 2 3 Net OCI during the year (1 ) 2 (25 ) (24 ) December 31, 2016 $ (1 ) $ (8 ) $ (61 ) $ (70 ) Amounts arising during the year — (2 ) (23 ) (25 ) Reclassifications from AOCI 1 1 5 7 Net OCI during the year 1 (1 ) (18 ) (18 ) December 31, 2017 $ — $ (9 ) $ (79 ) $ (88 )

Quarterly Financial Information

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Line Items]
Quarterly Financial Information (Unaudited)	QUARTERLY FINANCIAL, COMMON STOCK PRICE AND DIVIDEND DATA (Unaudited) PPL Corporation and Subsidiaries (Millions of Dollars, except per share data) For the Quarters Ended (a) March 31 June 30 Sept. 30 Dec. 31 2017 Operating revenues $ 1,951 $ 1,725 $ 1,845 $ 1,926 Operating income 796 702 777 793 Net income 403 292 355 78 Net income available to PPL common shareowners: (b) Basic EPS 0.59 0.43 0.52 0.11 Diluted EPS 0.59 0.43 0.51 0.11 Dividends declared per share of common stock (c) 0.3950 0.3950 0.3950 0.3950 Price per common share: High $ 37.70 $ 40.06 $ 39.83 $ 38.37 Low 33.94 37.11 37.36 30.76 2016 Operating revenues $ 2,011 $ 1,785 $ 1,889 $ 1,832 Operating income 823 725 786 714 Net income 481 483 473 465 Net income available to PPL common shareowners: (b) Basic EPS 0.71 0.71 0.70 0.68 Diluted EPS 0.71 0.71 0.69 0.68 Dividends declared per share of common stock (c) 0.38 0.38 0.38 0.38 Price per common share: High $ 38.07 $ 39.68 $ 37.71 $ 34.74 Low 32.80 36.27 33.63 32.19 (a) Quarterly results can vary depending on, among other things, weather. Accordingly, comparisons among quarters of a year may not be indicative of overall trends and changes in operations. (b) The sum of the quarterly amounts may not equal annual earnings per share due to changes in the number of common shares outstanding during the year or rounding. (c) PPL has paid quarterly cash dividends on its common stock in every year since 1946. Future dividends, declared at the discretion of the Board of Directors, will be dependent upon future earnings, cash flows, financial requirements and other factors.
PPL Electric Utilities Corp [Member]
Quarterly Financial Information Disclosure [Line Items]
Quarterly Financial Information (Unaudited)	QUARTERLY FINANCIAL DATA (Unaudited) PPL Electric Utilities Corporation and Subsidiaries (Millions of Dollars) For the Quarters Ended (a) March 31 June 30 Sept. 30 Dec. 31 2017 Operating revenues $ 573 $ 500 $ 547 $ 575 Operating income 159 156 189 197 Net income 79 77 95 111 2016 Operating revenues $ 585 $ 495 $ 539 $ 537 Operating income 180 154 176 154 Net income 94 79 90 77 (a) PPL Electric's business is seasonal in nature, with peak sales periods generally occurring in the winter and summer months. Accordingly, comparisons among quarters of a year may not be indicative of overall trends and changes in operations.

Summary of Significant Accoun56

Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)IntegerMW	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)
Utility Revenue (Details) [Abstract]
Domestic electric and gas revenue									$ 5,351	$ 5,297	$ 5,239
U.K. operating revenues									2,091	2,207	2,410
Domestic - other									5	13	20
Operating Revenues	$ 1,926	$ 1,845	$ 1,725	$ 1,951	$ 1,832	$ 1,889	$ 1,785	$ 2,011	7,447	7,517	7,669
Restricted Cash and Cash Equivalents (Numeric) [Abstract]
Restricted cash and cash equivalents	26				26				26	26
Property, Plant and Equipment (Numeric) [Abstract]
Interest costs, capitalized during the period									$ 11	11	$ 11
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Discount Rate Change For United Kingdom Pension Plans Numeric [Abstract]
Decrease in net periodic defined benefit cost from change in the discount rate										43
Decrease in net periodic defined benefit cost from change in the discount rate, after-tax										$ 34
Decrease in net periodic defined benefit cost from change in the discount rate, per share | $ / shares										$ 0.05
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	320				356				$ 320	$ 356
Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	107				158				107	158
Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	43				42				43	42
Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	170				156				$ 170	$ 156
Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									2.65%	2.73%	2.57%
Low Carbon Network Fund [Member]
Restricted Cash and Cash Equivalents (Numeric) [Abstract]
Restricted cash and cash equivalents	17				17				$ 17	$ 17
Other Restricted Cash [Member]
Restricted Cash and Cash Equivalents (Numeric) [Abstract]
Restricted cash and cash equivalents	9				9				9	9
Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				54				41	54	41	$ 44
Additions charged to income									28	44	49
Additions charged to other accounts									(1)	0	(2)
Deductions									30	31	50
Balance at end of period	51				54				$ 51	54	41
WPD [Member]
Summary of Significant Accounting Policies [Line Items]
Period of lag in reporting results for WPD (in months) | Integer									1
Revenue Recognition (Numeric) [Abstract]
Number of regulatory years later future demand revenue is affected									2 years
Percentage WPD's distribution network operators are able to retain of any under-spends									70.00%
Percentage WPD's distribution network operators bear of any over-spends									70.00%
Period of lag between incentives and penalties are reflected in customers' rates									2 years
Refunded/recovered period of lag for recovery of over and under-recovered amounts arising from 2014/15 onwards									2 years
Previous refunded/recovered period of lag for recovery of over and under-recovered amounts									1 year
LGE [Member] | Ohio Valley Electric Corporation [Member]
Cost Method Investments [Abstract]
Number of electric utilities that are equity owners | Integer									10
Number of companies power is supplied to | Integer									11
Ownership percentage									5.63%
Generation capacity in terms of ownership percentage (in MW) | MW									120
KU [Member] | Ohio Valley Electric Corporation [Member]
Cost Method Investments [Abstract]
Number of electric utilities that are equity owners | Integer									10
Number of companies power is supplied to | Integer									11
Ownership percentage									2.50%
Generation capacity in terms of ownership percentage (in MW) | MW									53
PPL Electric Utilities Corp [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues	575	$ 547	$ 500	573	537	$ 539	$ 495	585	$ 2,195	2,156	$ 2,124
Restricted Cash and Cash Equivalents (Numeric) [Abstract]
Restricted cash and cash equivalents	2				2				$ 2	2
Property, Plant and Equipment (Numeric) [Abstract]
Regulatory Asset Amortization Period									5 years
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	61				13				$ 61	$ 13
PPL Electric Utilities Corp [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									2.86%	2.63%	2.46%
PPL Electric Utilities Corp [Member] | Low Carbon Network Fund [Member]
Restricted Cash and Cash Equivalents (Numeric) [Abstract]
Restricted cash and cash equivalents	0				0				$ 0	$ 0
PPL Electric Utilities Corp [Member] | Other Restricted Cash [Member]
Restricted Cash and Cash Equivalents (Numeric) [Abstract]
Restricted cash and cash equivalents	2				2				2	2
PPL Electric Utilities Corp [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				28				16	28	16	$ 17
Additions charged to income									18	35	39
Additions charged to other accounts									0	0	0
Deductions									22	23	40
Balance at end of period	24				28				24	28	16
LG And E And KU Energy LLC [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									$ 3,156	3,141	$ 3,115
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	(23)				1				$ (23)	1
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	254				297				254	297
LG And E And KU Energy LLC [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	107				158				107	158
LG And E And KU Energy LLC [Member] | Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	43				42				43	42
LG And E And KU Energy LLC [Member] | Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	104				97				$ 104	$ 97
LG And E And KU Energy LLC [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.64%	3.69%	3.69%
LG And E And KU Energy LLC [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				24				23	$ 24	$ 23	$ 25
Additions charged to income									8	8	9
Additions charged to other accounts									(1)	0	(2)
Deductions									6	7	9
Balance at end of period	25				24				$ 25	24	23
LG And E And KU Energy LLC [Member] | LGE [Member] | Ohio Valley Electric Corporation [Member]
Cost Method Investments [Abstract]
Number of electric utilities that are equity owners | Integer									10
Number of companies power is supplied to | Integer									11
Ownership percentage									5.63%
Generation capacity in terms of ownership percentage (in MW) | MW									120
LG And E And KU Energy LLC [Member] | KU [Member] | Ohio Valley Electric Corporation [Member]
Cost Method Investments [Abstract]
Number of electric utilities that are equity owners | Integer									10
Number of companies power is supplied to | Integer									11
Ownership percentage									2.50%
Generation capacity in terms of ownership percentage (in MW) | MW									53
Louisville Gas And Electric Co [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									$ 1,453	1,430	$ 1,444
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	0				(18)				$ 0	(18)
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	131				143				131	143
Louisville Gas And Electric Co [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	45				60				45	60
Louisville Gas And Electric Co [Member] | Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	43				42				43	42
Louisville Gas And Electric Co [Member] | Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	43				41				$ 43	$ 41
Louisville Gas And Electric Co [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.63%	3.58%	3.65%
Louisville Gas And Electric Co [Member] | Ohio Valley Electric Corporation [Member]
Cost Method Investments [Abstract]
Number of electric utilities that are equity owners | Integer									10
Number of companies power is supplied to | Integer									11
Ownership percentage									5.63%
Generation capacity in terms of ownership percentage (in MW) | MW									120
Louisville Gas And Electric Co [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				2				1	$ 2	$ 1	$ 2
Additions charged to income									2	2	2
Additions charged to other accounts									(1)	1	0
Deductions									2	2	3
Balance at end of period	1				2				1	2	1
Kentucky Utilities Co [Member]
Utility Revenue (Details) [Abstract]
Operating Revenues									$ 1,744	1,749	$ 1,728
Defined Benefits [Abstract]
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization									30.00%
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis									10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis									30.00%
Income Taxes [Abstract]
Minimum percentage to be attained of likelihood of uncertain tax position being realized									50.00%
Intercompany tax receivables (payables)	0				(29)				$ 0	(29)
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	123				154				123	154
Kentucky Utilities Co [Member] | Fuel [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	62				98				62	98
Kentucky Utilities Co [Member] | Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	0				0				0	0
Kentucky Utilities Co [Member] | Material And Supplies [Member]
Fuel, Materials and Supplies (Details) [Abstract]
Fuel, materials and supplies on the Balance Sheet	61				56				$ 61	$ 56
Kentucky Utilities Co [Member] | Regulated Operations [Member] | Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates									3.66%	3.77%	3.71%
Kentucky Utilities Co [Member] | Ohio Valley Electric Corporation [Member]
Cost Method Investments [Abstract]
Number of electric utilities that are equity owners | Integer									10
Number of companies power is supplied to | Integer									11
Ownership percentage									2.50%
Generation capacity in terms of ownership percentage (in MW) | MW									53
Kentucky Utilities Co [Member] | Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period				$ 2				$ 2	$ 2	$ 2	$ 2
Additions charged to income									4	4	5
Additions charged to other accounts									(1)	0	0
Deductions									4	4	5
Balance at end of period	$ 1				$ 2				$ 1	$ 2	$ 2

Segment and Related Informati57

Segment and Related Information (Income Statement and Balance Sheet Data) (Details) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)Integer		Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)
Income Statement Data
Operating Revenues from external customers		$ 1,926	$ 1,845	$ 1,725	$ 1,951	$ 1,832	$ 1,889	$ 1,785	$ 2,011	$ 7,447		$ 7,517		$ 7,669
Depreciation										1,008		926		883
Amortization										97		80		59
Unrealized (gains) losses on derivatives and other hedging activities										178		19		(77)
Interest Expense										901		888		871
Income from Continuing Operations Before Income Taxes										1,912		2,550		2,068
Income Taxes										784		648		465
Deferred income taxes and investment tax credits										707		560		428
Net income		78	355	292	403	465	473	483	481	1,128		1,902		682
Loss from Discontinued Operations (net of income taxes)										0		0		(921)
Cash Flow Data
Expenditures for long-lived assets										3,171		2,957		3,570
Balance Sheet Data
Total Assets		41,479				38,315				$ 41,479		38,315
Segment Information (Numeric) [Abstract]
Number of reportable segments | Integer										3
PPL Energy Supply Spinoff [Member]
Income Statement Data
Loss from Discontinued Operations (net of income taxes)														(921)
Gain (loss) on disposal group														(879)
U.K. Regulated [Member]
Income Statement Data
Operating Revenues from external customers										$ 2,091		2,207		2,410
Depreciation										230		233		242
Amortization										34		16		6
Unrealized (gains) losses on derivatives and other hedging activities										166		13		(88)
Interest Expense										397		402		417
Income from Continuing Operations Before Income Taxes										804		1,479		1,249
Income Taxes										152		233		128
Deferred income taxes and investment tax credits										66		31		45
Net income										652		1,246		1,121
Cash Flow Data
Expenditures for long-lived assets										1,015		1,031		1,242
Balance Sheet Data
Total Assets		16,813				14,537				16,813		14,537
Segment Information (Numeric) [Abstract]
Net property, plant and equipment not subject to accounting for the effects of certain types of regulation		12,500				10,800				12,500		10,800
Kentucky Regulated [Member]
Income Statement Data
Operating Revenues from external customers										3,156		3,141		3,115
Depreciation										439		404		382
Amortization										24		29		27
Unrealized (gains) losses on derivatives and other hedging activities										6		6		11
Interest Expense										261		260		232
Income from Continuing Operations Before Income Taxes										645		640		547
Income Taxes										359		242		221
Deferred income taxes and investment tax credits										294		291		236
Net income										286		398		326
Cash Flow Data
Expenditures for long-lived assets										892		791		1,210
Balance Sheet Data
Total Assets		14,468				14,037				14,468		14,037
Pennsylvania Regulated [Member]
Income Statement Data
Operating Revenues from external customers										2,195		2,156		2,124
Depreciation										309		253		214
Amortization										33		32		26
Interest Expense										142		129		130
Income from Continuing Operations Before Income Taxes										575		550		416
Income Taxes										216		212		164
Deferred income taxes and investment tax credits										257		221		220
Net income										359		338		252
Cash Flow Data
Expenditures for long-lived assets										1,254		1,134		1,107
Balance Sheet Data
Total Assets		10,082				9,426				10,082		9,426
Corporate And Other [Member]
Income Statement Data
Operating Revenues from external customers										5		13		20
Depreciation										30		36		45
Amortization										6		3		0
Unrealized (gains) losses on derivatives and other hedging activities										6		0		0
Interest Expense										101		97		92
Income from Continuing Operations Before Income Taxes										(112)		(119)		(144)
Income Taxes										57		(39)		(48)
Deferred income taxes and investment tax credits										90		17		(73)
Net income										(169)		(80)		(96)
Cash Flow Data
Expenditures for long-lived assets										10		1		11
Balance Sheet Data
Total Assets		116				315				116		315
Discontinued Operations [Member]
Income Statement Data
Loss from Discontinued Operations (net of income taxes)										0		0		(921)
PPL Electric Utilities Corp [Member]
Income Statement Data
Operating Revenues from external customers		575	547	500	573	537	539	495	585	2,195		2,156		2,124
Depreciation										309		253		214
Amortization										33		32		26
Interest Expense										142		129		130
Income from Continuing Operations Before Income Taxes										575		552		416
Income Taxes										213		212		164
Deferred income taxes and investment tax credits										258		221		220
Net income		111	$ 95	$ 77	$ 79	77	$ 90	$ 79	$ 94	362	[1]	340	[1]	252	[1]
Balance Sheet Data
Total Assets		10,082				9,426				$ 10,082		9,426
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										2
Number of reportable segments | Integer										1
LG And E And KU Energy LLC [Member]
Income Statement Data
Operating Revenues from external customers										$ 3,156		3,141		3,115
Depreciation										439		404		382
Amortization										24		29		27
Interest Expense										197		197		178
Income from Continuing Operations Before Income Taxes										691		686		603
Income Taxes										375		257		239
Deferred income taxes and investment tax credits										294		291		236
Net income										316		429		364
Balance Sheet Data
Total Assets		14,802				14,371				$ 14,802		14,371
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										1
Number of reportable segments | Integer										1
Louisville Gas And Electric Co [Member]
Income Statement Data
Operating Revenues from external customers										$ 1,453		1,430		1,444
Depreciation										183		170		162
Amortization										14		14		11
Interest Expense										71		71		57
Income from Continuing Operations Before Income Taxes										344		329		299
Income Taxes										131		126		114
Deferred income taxes and investment tax credits										126		147		126
Net income	[2]									213		203		185
Balance Sheet Data
Total Assets		6,559				6,300				$ 6,559		6,300
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										1
Number of reportable segments | Integer										1
Kentucky Utilities Co [Member]
Income Statement Data
Operating Revenues from external customers										$ 1,744		1,749		1,728
Depreciation										255		234		220
Amortization										9		14		13
Interest Expense										96		96		82
Income from Continuing Operations Before Income Taxes										418		428		374
Income Taxes										159		163		140
Deferred income taxes and investment tax credits										152		126		160
Net income	[3]									259		265		$ 234
Balance Sheet Data
Total Assets		$ 8,254				$ 8,085				$ 8,254		$ 8,085
Segment Information (Numeric) [Abstract]
Number of operating segments | Integer										1
Number of reportable segments | Integer										1
[1]	Net income equals comprehensive income.
[2]	Net income equals comprehensive income.
[3]	Net income approximates comprehensive income.

Segment and Related Informati58

Segment and Related Information (Geographic Data) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	$ 1,926	$ 1,845	$ 1,725	$ 1,951	$ 1,832	$ 1,889	$ 1,785	$ 2,011	$ 7,447	$ 7,517	$ 7,669
Long-lived assets	33,787				30,772				33,787	30,772
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers									5,356	5,310	5,259
Long-lived assets	20,936				19,595				20,936	19,595
U.K. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 12,851				$ 11,177				12,851	11,177
U.K. Regulated [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers									$ 2,091	$ 2,207	$ 2,410

Preferred Securities (Details)

Preferred Securities (Details) - $ / shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Preferred Stock [Member]
Preferred Securities [Line Items]
Shares authorized	10,000,000
Preferred Stock, Shares Issued	0	0	0
Preferred Stock, Shares Outstanding	0	0	0
PPL Electric Utilities Corp [Member] | Preferred Stock [Member]
Preferred Securities [Line Items]
Shares authorized	20,629,936
Preferred Stock, Shares Issued	0	0	0
Preferred Stock, Shares Outstanding	0	0	0
Louisville Gas And Electric Co [Member] | Preferred Stock [Member]
Preferred Securities [Line Items]
Shares authorized	1,720,000
Preferred Stock, Shares Issued	0	0	0
Preferred Stock, Shares Outstanding	0	0	0
Par value of stock	$ 25
Louisville Gas And Electric Co [Member] | Preferred Stock Without Par Value [Member]
Preferred Securities [Line Items]
Shares authorized	6,750,000
Preferred Stock, Shares Issued	0	0	0
Preferred Stock, Shares Outstanding	0	0	0
Kentucky Utilities Co [Member] | Preferred Stock Without Par Value [Member]
Preferred Securities [Line Items]
Shares authorized	5,300,000
Preferred Stock, Shares Issued	0	0	0
Preferred Stock, Shares Outstanding	0	0	0
Kentucky Utilities Co [Member] | Preference Stock Without Par Value [Member]
Preferred Securities [Line Items]
Shares authorized	2,000,000
Preferred Stock, Shares Issued	0	0	0
Preferred Stock, Shares Outstanding	0	0	0

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income (Numerator)
Income from continuing operations after income taxes									$ 1,128	$ 1,902	$ 1,603
Less amounts allocated to participating securities									2	6	6
Income from continuing operations after income taxes available to PPL common shareowners - Basic									1,126	1,896	1,597
Income from continuing operations after income taxes available to PPL common shareowners - Diluted									1,126	1,896	1,597
Income (loss) from discontinued operations (net of income taxes) available to PPL common shareowners - Basic									0	0	(921)
Income (loss) from discontinued operations (net of income taxes) available to PPL common shareowners - Diluted									0	0	(921)
Net income	$ 78	$ 355	$ 292	$ 403	$ 465	$ 473	$ 483	$ 481	1,128	1,902	682
Less amounts allocated to participating securities									2	6	2
Net income available to PPL common shareowners - Basic									1,126	1,896	680
Net income available to PPL common shareowners - Diluted									$ 1,126	$ 1,896	$ 680
Shares of Common Stock (Denominator)
Weighted-average shares - Basic EPS (in shares)									685,240	677,592	669,814
Add incremental non-participating securities:
Share-based payment awards (in shares)									2,094	2,854	2,772
Weighted-average shares - Diluted EPS (in shares)									687,334	680,446	672,586
Basic EPS - Available to PPL common shareowners:
Income from continuing operations after income taxes (in dollars per share)									$ 1.64	$ 2.80	$ 2.38
Income (loss) from discontinued operations (net of income taxes) (in dollars per share)									0	0	(1.37)
Net Income (in dollars per share)	$ 0.11	$ 0.52	$ 0.43	$ 0.59	$ 0.68	$ 0.70	$ 0.71	$ 0.71	1.64	2.80	1.01
Diluted EPS - Available to PPL common shareowners:
Income from continuing operations after income taxes (in dollars per share)									1.64	2.79	2.37
Income (loss) from discontinued operations (net of income taxes) (in dollars per share)									0	0	(1.36)
Net Income (in dollars per share)	$ 0.11	$ 0.51	$ 0.43	$ 0.59	$ 0.68	$ 0.69	$ 0.71	$ 0.71	$ 1.64	$ 2.79	$ 1.01
Shares Issued (Numeric) [Abstract]
Common stock issued under stock-based compensation plans (in shares)									1,748
Common stock issued under DRIP (in shares)									1,552
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computations of diluted EPS									696	696	1,087
Performance Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computations of diluted EPS									0	176	36

Income and Other Taxes (Tax Ref

Income and Other Taxes (Tax Reform) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Reform [Line Items]
Income Tax Expense (Benefit)	$ 784	$ 648	$ 465
Net Increase in Regulatory Liability	12	59	(42)
Deferred Tax Liabilities, Net	2,438	3,862
Tax Cuts And Jobs Act [Member]
Tax Reform [Line Items]
Taxable Deemed Dividend	462
Income Tax Expense (Benefit)	321
Net Increase in Regulatory Liability	2,185
Deferred Tax Liabilities, Net	101
Tax Cuts And Jobs Act [Member] | Non-Regulated Deferred Tax Assets And Liabilities [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	220
PPL Electric Utilities Corp [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	213	212	164
Net Increase in Regulatory Liability	5	62	(35)
Deferred Tax Liabilities, Net	1,154	1,899
PPL Electric Utilities Corp [Member] | Tax Cuts And Jobs Act [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(13)
Net Increase in Regulatory Liability	1,019
PPL Electric Utilities Corp [Member] | Tax Cuts And Jobs Act [Member] | Non-Regulated Deferred Tax Assets And Liabilities [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	(13)
LG And E And KU Energy LLC [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	375	257	239
Deferred Tax Liabilities, Net	866	1,735
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	112
Net Increase in Regulatory Liability	1,166
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member] | Non-Regulated Deferred Tax Assets And Liabilities [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	112
Louisville Gas And Electric Co [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	131	126	114
Deferred Tax Liabilities, Net	572	974
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	0
Net Increase in Regulatory Liability	532
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member] | Non-Regulated Deferred Tax Assets And Liabilities [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	0
Kentucky Utilities Co [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	159	163	$ 140
Deferred Tax Liabilities, Net	691	$ 1,170
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	0
Net Increase in Regulatory Liability	634
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member] | Non-Regulated Deferred Tax Assets And Liabilities [Member]
Tax Reform [Line Items]
Income Tax Expense (Benefit)	$ 0

Income and Other Taxes (Deferre

Income and Other Taxes (Deferred Tax Assets and Liabilities and Loss Carryforwards) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income (Loss) from Continuing Operations (Details) [Abstract]
Domestic income	$ 874	$ 1,463	$ 968
Foreign income	1,038	1,087	1,100
Income Before Income Taxes	1,912	2,550	2,068
Deferred Tax Assets
Deferred investment tax credits	33	51
Regulatory liabilities	62	94
Income taxes due to customer	499	0
Accrued pension costs	159	250
Federal loss carryforwards	356	565
State loss carryforwards	409	326
Federal and state tax credit carryforwards	455	256
Foreign capital loss carryforwards	329	302
Foreign loss carryforwards	2	3
Foreign - pensions	(32)	41
Foreign - regulatory obligations	2	6
Foreign - other	7	5
Contributions in aid of construction	134	141
Domestic - other	104	188
Unrealized losses on qualifying derivatives	10	20
Valuation allowances	(838)	(593)
Total deferred tax assets	1,691	1,655
Deferred Tax Liabilities
Domestic plant - net	3,168	4,325
Taxes recoverable through future rates	0	170
Regulatory assets	211	343
Reacquired debt costs	15	25
Foreign plant - net	726	640
Domestic - other	9	14
Total deferred tax liabilities	4,129	5,517
Net deferred tax liability	2,438	3,862
Loss carryforwards
Federal loss carryforwards	356	565
Federal [Member]
Deferred Tax Assets
Federal loss carryforwards	349
Loss carryforwards
Net operating losses	1,662
Charitable contributions	36
Federal loss carryforwards	349
Charitable contribution carryforwards	7
Loss carryforward valuation allowance on net operating losses	0
Charitable Contributions Loss Carryforwards valuation allowance	0
State [Member]
Deferred Tax Assets
State loss carryforwards	407
Loss carryforwards
Net operating losses	5,512
Charitable contributions	26
Charitable contribution carryforwards	2
Loss carryforward valuation allowance on net operating losses	(348)
Charitable Contributions Loss Carryforwards valuation allowance	0
Foreign Tax Authority [Member]
Deferred Tax Assets
Foreign capital loss carryforwards	329
Foreign loss carryforwards	2
Loss carryforwards
Net operating losses	10
Capital losses	1,938
Loss carryforward valuation allowance on net operating losses	0
Loss carryforward valuation allowance on capital losses	(329)
Tax Cuts And Jobs Act [Member]
Deferred Tax Liabilities
Net deferred tax liability	101
Other Noncurrent Assets [Member]
Deferred Tax Liabilities
Deferred Tax Assets, State Taxes	$ 24	27
Minimum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2029
Expiration - charitable contributions	Dec. 31, 2020
Minimum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2018
Expiration - charitable contributions	Dec. 31, 2018
Maximum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
Maximum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
PPL Electric Utilities Corp [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 575	552	416
Deferred Tax Assets
Regulatory liabilities	25	34
Income taxes due to customer	193	0
Accrued pension costs	63	107
Federal loss carryforwards	91	147
State loss carryforwards	19	22
Contributions in aid of construction	117	112
Domestic - other	45	81
Total deferred tax assets	553	503
Deferred Tax Liabilities
Domestic plant - net	1,544	2,001
Taxes recoverable through future rates	0	141
Regulatory assets	150	240
Reacquired debt costs	8	15
Domestic - other	5	5
Total deferred tax liabilities	1,707	2,402
Net deferred tax liability	1,154	1,899
Loss carryforwards
Federal loss carryforwards	91	147
PPL Electric Utilities Corp [Member] | Federal [Member]
Deferred Tax Assets
Federal loss carryforwards	89
Loss carryforwards
Net operating losses	426
Charitable contributions	8
Federal loss carryforwards	89
Charitable contribution carryforwards	2
PPL Electric Utilities Corp [Member] | State [Member]
Deferred Tax Assets
State loss carryforwards	18
Loss carryforwards
Net operating losses	233
Charitable contributions	13
Charitable contribution carryforwards	$ 1
PPL Electric Utilities Corp [Member] | Minimum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2031
Expiration - charitable contributions	Dec. 31, 2020
PPL Electric Utilities Corp [Member] | Minimum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2030
Expiration - charitable contributions	Dec. 31, 2018
PPL Electric Utilities Corp [Member] | Maximum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
PPL Electric Utilities Corp [Member] | Maximum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2032
Expiration - charitable contributions	Dec. 31, 2022
LG And E And KU Energy LLC [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 691	686	603
Deferred Tax Assets
Deferred investment tax credits	33	51
Regulatory liabilities	37	60
Income taxes due to customer	305	15
Accrued pension costs	29	58
Federal loss carryforwards	150	248
State loss carryforwards	41	35
Federal and state tax credit carryforwards	181	186
Contributions in aid of construction	17	29
Domestic - other	26	49
Unrealized losses on qualifying derivatives	7	12
Valuation allowances	(8)	(11)
Total deferred tax assets	818	732
Deferred Tax Liabilities
Domestic plant - net	1,615	2,352
Regulatory assets	61	102
Domestic - other	8	13
Total deferred tax liabilities	1,684	2,467
Net deferred tax liability	866	1,735
Loss carryforwards
Federal loss carryforwards	150	248
LG And E And KU Energy LLC [Member] | Federal [Member]
Deferred Tax Assets
Federal loss carryforwards	150
Loss carryforwards
Net operating losses	713
Charitable contributions	14
Federal loss carryforwards	150
Charitable contribution carryforwards	3
Loss carryforward valuation allowance on net operating losses	0
Charitable Contributions Loss Carryforwards valuation allowance	0
LG And E And KU Energy LLC [Member] | State [Member]
Deferred Tax Assets
Federal loss carryforwards	41
Loss carryforwards
Net operating losses	874
Federal loss carryforwards	41
Loss carryforward valuation allowance on net operating losses	$ 0
LG And E And KU Energy LLC [Member] | Minimum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2028
Expiration - charitable contributions	Dec. 31, 2020
LG And E And KU Energy LLC [Member] | Minimum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2028
LG And E And KU Energy LLC [Member] | Maximum [Member] | Federal [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Expiration - charitable contributions	Dec. 31, 2022
LG And E And KU Energy LLC [Member] | Maximum [Member] | State [Member]
Loss carryforwards
Expiration - operating losses	Dec. 31, 2037
Louisville Gas And Electric Co [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 344	329	299
Deferred Tax Assets
Deferred investment tax credits	9	14
Regulatory liabilities	21	34
Income taxes due to customer	142	17
Federal loss carryforwards	29	80
Contributions in aid of construction	11	18
Domestic - other	12	17
Unrealized losses on qualifying derivatives	7	12
Total deferred tax assets	231	192
Deferred Tax Liabilities
Domestic plant - net	724	1,058
Regulatory assets	40	65
Accrued pension costs	34	35
Domestic - other	5	8
Total deferred tax liabilities	803	1,166
Net deferred tax liability	572	974
Loss carryforwards
Federal loss carryforwards	29	80
Louisville Gas And Electric Co [Member] | Federal [Member]
Loss carryforwards
Net operating losses	$ 140
Expiration - operating losses	Dec. 31, 2035
Kentucky Utilities Co [Member]
Income (Loss) from Continuing Operations (Details) [Abstract]
Income Before Income Taxes	$ 418	428	$ 374
Deferred Tax Assets
Deferred investment tax credits	24	37
Regulatory liabilities	16	26
Income taxes due to customer	163	0
Federal loss carryforwards	13	79
Contributions in aid of construction	6	11
Domestic - other	9	11
Total deferred tax assets	231	164
Deferred Tax Liabilities
Domestic plant - net	882	1,280
Regulatory assets	21	37
Accrued pension costs	17	12
Domestic - other	2	5
Total deferred tax liabilities	922	1,334
Net deferred tax liability	691	1,170
Loss carryforwards
Federal loss carryforwards	13	$ 79
Kentucky Utilities Co [Member] | Federal [Member]
Loss carryforwards
Net operating losses	$ 61
Expiration - operating losses	Dec. 31, 2035

Income and Other Taxes (Credit

Income and Other Taxes (Credit Carryforwards and Valuation Allowances and Reserves) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Credit carryforwards
Deferred tax asset credit carryforwards	$ 455	$ 256
Tax Cuts And Jobs Act [Member]
Credit carryforwards
Credit Carryforward Valuation Allowance Foreign Tax Credits	122
Taxable Deemed Dividend	462
Deferred Tax Assets, Foreign Tax Credit Carryforwards	205
Permanently reinvested cumulative undistributed foreign earnings	6,000
Valuation Allowances and Reserves (Details) [Roll Forward]
Increase of the valuation allowance as a result of the expected future utilization of foreign tax credits	145
Valuation Allowance Of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	593	662	$ 622
Additions charged to income	256	17	24
Additions charged to other accounts	0	2	77
Deductions	11	88	61
Balance at end of period	838	593	662
Increase of the valuation allowance as a result of the expected future utilization of foreign tax credits	145
Increase of the valuation allowance as a result of the reduction in the U.S. federal corporate income tax rate	62
Reduction of the valuation allowance as a result of the reduction in the UK statutory income tax rate		(19)	(44)
Valuation Rollforward Specific Transaction Deductions Exchange Rates		65
Investment Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	133
Credit Carryforward Valuation Allowance Investment Tax Credit	$ 0
Investment Tax Credit [Member] | Federal [Member] | Minimum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2025
Investment Tax Credit [Member] | Federal [Member] | Maximum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2036
Foreign Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	$ 267
Credit Carryforward Valuation Allowance Foreign Tax Credits	(148)
Foreign Tax Credit [Member] | Federal [Member] | Tax Year 2016 [Member] | Tax Cuts And Jobs Act [Member]
Credit carryforwards
Deferred Tax Assets, Foreign Tax Credit Carryforwards	62
Foreign Tax Credit [Member] | Federal [Member] | Tax Year 2017 [Member] | Tax Cuts And Jobs Act [Member]
Credit carryforwards
Deferred Tax Assets, Foreign Tax Credit Carryforwards	$ 205
Foreign Tax Credit [Member] | Federal [Member] | Minimum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2024
Foreign Tax Credit [Member] | Federal [Member] | Maximum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2027
Alternative Minimum Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	$ 30
Credit Carryforward Valuation Allowance Alternative Minimum Tax Credit	0
Other [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	24
Credit Carryforward Valuation Allowance Other	$ (8)
Other [Member] | Federal [Member] | Minimum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2019
Other [Member] | Federal [Member] | Maximum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2037
Other [Member] | State [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	$ 1
Credit Carryforward Valuation Allowance Other	0
LG And E And KU Energy LLC [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	181	186
LG And E And KU Energy LLC [Member] | Valuation Allowance Of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	11	12	0
Additions charged to other accounts	4	0	12
Deductions	7	1	0
Balance at end of period	8	$ 11	$ 12
LG And E And KU Energy LLC [Member] | Investment Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	133
Credit Carryforward Valuation Allowance Investment Tax Credit	$ 0
LG And E And KU Energy LLC [Member] | Investment Tax Credit [Member] | Federal [Member] | Minimum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2025
LG And E And KU Energy LLC [Member] | Investment Tax Credit [Member] | Federal [Member] | Maximum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2036
LG And E And KU Energy LLC [Member] | Alternative Minimum Tax Credit [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	$ 27
Credit Carryforward Valuation Allowance Alternative Minimum Tax Credit	0
LG And E And KU Energy LLC [Member] | Other [Member] | Federal [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	21
Credit Carryforward Valuation Allowance Other	$ (8)
LG And E And KU Energy LLC [Member] | Other [Member] | Federal [Member] | Minimum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2019
LG And E And KU Energy LLC [Member] | Other [Member] | Federal [Member] | Maximum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2037
LG And E And KU Energy LLC [Member] | Other [Member] | State [Member]
Credit carryforwards
Deferred tax asset credit carryforwards	$ 1
Credit Carryforward Valuation Allowance Other	0
Louisville Gas And Electric Co [Member] | Other [Member] | Federal [Member]
Credit carryforwards
Tax Credit Carryforward, Amount	$ 6
Louisville Gas And Electric Co [Member] | Other [Member] | Federal [Member] | Minimum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2034
Louisville Gas And Electric Co [Member] | Other [Member] | Federal [Member] | Maximum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2037
Kentucky Utilities Co [Member] | Other [Member] | Federal [Member]
Credit carryforwards
Tax Credit Carryforward, Amount	$ 6
Kentucky Utilities Co [Member] | Other [Member] | Federal [Member] | Minimum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2034
Kentucky Utilities Co [Member] | Other [Member] | Federal [Member] | Maximum [Member]
Credit carryforwards
Tax Credit Carryforward Expiration Date 1	Dec. 31, 2037

Income and Other Taxes (Income

Income and Other Taxes (Income Tax Expense and Reconciliation of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense (Benefit)
Current - Federal	$ 6	$ (14)	$ (26)
Current - State	25	21	25
Current - Foreign	45	80	89
Total Current Expense (Benefit)	76	87	88
Deferred - Federal	532	385	699
Deferred - State	88	89	68
Deferred - Foreign	133	86	41
Total Deferred Expense (Benefit), excluding operating loss carry forwards	753	560	808
Amortization of investment tax credit - Federal	(3)	(3)	(4)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	(16)	25	(396)
Deferred - State	(26)	(21)	(31)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	(42)	4	(427)
Total income tax from continuing operations	784	648	465
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	519	393	273
Total income tax expense - State	87	89	62
Total income tax expense - Foreign	178	166	130
Total income tax from continuing operations	784	648	465
Discontinued operations	0	0	(30)
Stock-based compensation recorded to Earnings Reinvested	0	(7)	0
Other comprehensive income	(34)	(6)	(2)
Valuation allowance on state deferred taxes recorded to other comprehensive income	(1)	1	(4)
Total income tax expense (benefits) excluded from incomes taxes from continuing operations	(35)	(12)	(36)
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 669	$ 893	$ 724
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 46	$ 46	$ 31
Valuation allowance adjustments	36	16	24
Stock-based compensation	(3)	(10)	0
Deferred tax impact of U.S. tax reform	220	0	0
Impact of lower U.K. income tax rates	(176)	(177)	(176)
U.S. income tax on foreign earnings - net of foreign tax credit	47	(42)	8
Federal and state tax reserve adjustments	0	0	(22)
Foreign income return adjustments	(8)	2	0
Impact of the United Kingdom Finance Acts on deferred tax balances	(16)	(49)	(91)
Depreciation not normalized	(10)	(10)	(5)
Interest benefit on United Kingdom financing entities	(16)	(17)	(20)
Other	(5)	(4)	(8)
Total increase (decrease)	115	(245)	(259)
Total income tax from continuing operations	$ 784	$ 648	$ 465
Effective income tax rate	41.00%	25.40%	22.50%
Expense related to increased Pennsylvania net operating loss carryforwards expected to be unutilized	$ 16	$ 13	$ 12
Expense related to federal tax credit carryforwards that are expected to expire as a result of future taxable earnings			12
Benefit recorded in continuing operations related to the settlement of the IRS audit for tax years 1998-2011			12
Benefit recorded in continuing operations related to the planned amendment of a prior period tax return.			(9)
Deferred Income Tax Expense Benefit Statutory Tax Rate Change		42	90
Deferred Income Tax Expense Benefit Foreign Pension Contribution	35
Taxes, other than income
State gross receipts	102	100	89
State capital stock	(6)	0	0
Foreign property	127	135	148
Domestic property and other	69	66	62
Total	292	301	299
Previously recorded reserves			17
Income Tax Reconciliation Valuation Allowance Foreign Tax Credits	23
Tax Cuts And Jobs Act [Member]
Income Tax Expense (Benefit)
Deferred Income Tax Expense (Benefit) Tax Rate Change	220
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	321
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	321
Increase (decrease) due to:
Total income tax from continuing operations	321
Deferred Income Tax Expense Benefit Tax Reform	83
Taxable Deemed Dividend	462
Taxes, other than income
Deferred Income Tax Expense (Benefit) Net Operating Loss	162
Deferred Income Tax Benefit Foreign Tax Credits	60
Deferred Tax Assets, Foreign Tax Credit Carryforwards	205
Valuation Rollfoward Specific Transaction Additions Foreign Tax Credits	145
Credit Carryforward Valuation Allowance Foreign Tax Credits	122
Credit Carryforward Expected Realization Foreign Tax Credits	83
PPL Electric Utilities Corp [Member]
Income Tax Expense (Benefit)
Current - Federal	(65)	(29)	(80)
Current - State	20	19	23
Total Current Expense (Benefit)	(45)	(10)	(57)
Deferred - Federal	234	193	287
Deferred - State	29	29	12
Total Deferred Expense (Benefit), excluding operating loss carry forwards	263	222	299
Amortization of investment tax credit - Federal	0	0	0
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	(5)	0	(75)
Deferred - State	0	0	(3)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	(5)	0	(78)
Total income tax from continuing operations	213	212	164
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	164	164	132
Total income tax expense - State	49	48	32
Total income tax from continuing operations	213	212	164
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 201	$ 193	$ 146
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 36	$ 36	$ 25
Stock-based compensation	(2)	(6)	0
Deferred tax impact of U.S. tax reform	(13)	0	0
Depreciation not normalized	(8)	(8)	(4)
Other	(1)	(3)	(3)
Total increase (decrease)	12	19	18
Total income tax from continuing operations	$ 213	$ 212	$ 164
Effective income tax rate	37.00%	38.40%	39.40%
Taxes, other than income
State gross receipts	$ 102	$ 100	$ 89
Domestic property and other	5	5	5
Total	107	105	94
Previously recorded reserves			17
PPL Electric Utilities Corp [Member] | Tax Cuts And Jobs Act [Member]
Income Tax Expense (Benefit)
Deferred Income Tax Expense (Benefit) Tax Rate Change	(13)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	(13)
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	(13)
Increase (decrease) due to:
Total income tax from continuing operations	(13)
LG And E And KU Energy LLC [Member]
Income Tax Expense (Benefit)
Current - Federal	74	(36)	2
Current - State	6	1	1
Total Current Expense (Benefit)	80	(35)	3
Deferred - Federal	268	248	405
Deferred - State	32	38	32
Total Deferred Expense (Benefit), excluding operating loss carry forwards	300	286	437
Amortization of investment tax credit - Federal	(3)	(3)	(3)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	(2)	10	(198)
Deferred - State	0	(1)	0
Total Tax Expense (Benefit) of Operating Loss Carryforwards	(2)	9	(198)
Total income tax from continuing operations	375	257	239
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	337	219	206
Total income tax expense - State	38	38	33
Total income tax from continuing operations	375	257	239
Other comprehensive income	(10)	(16)	(1)
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 242	$ 240	$ 211
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 25	$ 25	$ 22
Valuation allowance adjustments	0	0	12
Stock-based compensation	1	(3)	0
Deferred tax impact of U.S. tax reform	112	0	0
Amortization of investment tax credit	(3)	(3)	(3)
Other	(2)	(2)	(3)
Total increase (decrease)	133	17	28
Total income tax from continuing operations	$ 375	$ 257	$ 239
Effective income tax rate	54.30%	37.50%	39.60%
Taxes, other than income
Domestic property and other	$ 65	$ 62	$ 57
Total	65	62	57
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member]
Income Tax Expense (Benefit)
Deferred Income Tax Expense (Benefit) Tax Rate Change	108
Deferred Income Tax Expense (Benefit) Expiring Tax Credit	4
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	112
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	112
Increase (decrease) due to:
Total income tax from continuing operations	112
Deferred Income Tax Expense Benefit Tax Reform	112
Louisville Gas And Electric Co [Member]
Income Tax Expense (Benefit)
Current - Federal	0	(22)	(15)
Current - State	5	1	3
Total Current Expense (Benefit)	5	(21)	(12)
Deferred - Federal	112	134	190
Deferred - State	14	18	13
Total Deferred Expense (Benefit), excluding operating loss carry forwards	126	152	203
Amortization of investment tax credit - Federal	(1)	(1)	(1)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	1	(4)	(76)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	1	(4)	(76)
Total income tax from continuing operations	131	126	114
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	112	107	98
Total income tax expense - State	19	19	16
Total income tax from continuing operations	131	126	114
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 120	$ 115	$ 105
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 13	$ 12	$ 11
Amortization of investment tax credit	(1)	(1)	(1)
Other	(1)	0	(1)
Total increase (decrease)	11	11	9
Total income tax from continuing operations	$ 131	$ 126	$ 114
Effective income tax rate	38.10%	38.30%	38.10%
Taxes, other than income
Domestic property and other	$ 33	$ 32	$ 28
Total	33	32	28
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member]
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	0
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	0
Increase (decrease) due to:
Total income tax from continuing operations	0
Kentucky Utilities Co [Member]
Income Tax Expense (Benefit)
Current - Federal	0	31	(21)
Current - State	7	5	1
Total Current Expense (Benefit)	7	36	(20)
Deferred - Federal	138	131	240
Deferred - State	16	19	19
Total Deferred Expense (Benefit), excluding operating loss carry forwards	154	150	259
Amortization of investment tax credit - Federal	(2)	(2)	(2)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	0	(21)	(97)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	0	(21)	(97)
Total income tax from continuing operations	159	163	140
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax expense - Federal	136	139	120
Total income tax expense - State	23	24	20
Total income tax from continuing operations	159	163	140
Other comprehensive income	1	(1)	(1)
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	$ 146	$ 150	$ 131
Federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	$ 15	$ 16	$ 13
Amortization of investment tax credit	(2)	(2)	(2)
Other	0	(1)	(2)
Total increase (decrease)	13	13	9
Total income tax from continuing operations	$ 159	$ 163	$ 140
Effective income tax rate	38.00%	38.10%	37.40%
Taxes, other than income
Domestic property and other	$ 32	$ 30	$ 29
Total	32	$ 30	$ 29
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member]
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	0
Income tax expense (benefit) from continuing operations [Abstract]
Total income tax from continuing operations	0
Increase (decrease) due to:
Total income tax from continuing operations	$ 0

Income and Other Taxes (Unrecog

Income and Other Taxes (Unrecognized to End) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017Integer	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	4
Income Tax Other (Numeric) [Abstract]
Benefit recorded related to the settlement of the IRS audit for tax years 1998-2011 | $		$ 3	$ 24
Benefit recorded in continuing operations related to the settlement of the IRS audit for tax years 1998-2011 | $			$ 12
US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2013 and prior
Pennsylvania - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2011 and prior
Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2012 and prior
United Kingdom - Foreign [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2014 and prior
PPL Electric Utilities Corp [Member]
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
PPL Electric Utilities Corp [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2013 and prior
PPL Electric Utilities Corp [Member] | Pennsylvania - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2011 and prior
LG And E And KU Energy LLC [Member]
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
LG And E And KU Energy LLC [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2013 and prior
LG And E And KU Energy LLC [Member] | Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2012 and prior
Louisville Gas And Electric Co [Member]
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
Louisville Gas And Electric Co [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2013 and prior
Louisville Gas And Electric Co [Member] | Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2012 and prior
Kentucky Utilities Co [Member]
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
Kentucky Utilities Co [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2013 and prior
Kentucky Utilities Co [Member] | Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2012 and prior

Utility Rate Regulation (Regula

Utility Rate Regulation (Regulatory Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Current regulatory assets	$ 34	$ 39
Noncurrent regulatory assets	1,504	1,918
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	6
Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6	11
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	7
Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	3
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	880	947
Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets	15	6
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	3	340
Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	5
Noncurrent regulatory assets	33	57
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	54	61
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	26	31
Terminated Interest Rate Swap [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	92	98
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	173	159
Asset Retirement Obligations Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	234	211
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	1
Noncurrent regulatory assets	9	14
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	16	19
Noncurrent regulatory assets	709	1,094
PPL Electric Utilities Corp [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	7
PPL Electric Utilities Corp [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	504	549
PPL Electric Utilities Corp [Member] | Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets	15	6
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	3	340
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	5
Noncurrent regulatory assets	0	9
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	29	36
PPL Electric Utilities Corp [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Terminated Interest Rate Swap [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	173	159
PPL Electric Utilities Corp [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1	1
Noncurrent regulatory assets	0	1
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets	18	20
Noncurrent regulatory assets	795	824
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	6
LG And E And KU Energy LLC [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6	11
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	3
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	376	398
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	33	48
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	25	25
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	26	31
LG And E And KU Energy LLC [Member] | Terminated Interest Rate Swap [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	92	98
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	234	211
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	0
Noncurrent regulatory assets	9	13
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	12	9
Noncurrent regulatory assets	411	450
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	6
Louisville Gas And Electric Co [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	3
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	234	246
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	18	26
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	16	16
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	26	31
Louisville Gas And Electric Co [Member] | Terminated Interest Rate Swap [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	54	57
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	61	70
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	0
Noncurrent regulatory assets	2	4
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6	11
Noncurrent regulatory assets	384	374
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Kentucky Utilities Co [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6	11
Kentucky Utilities Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	142	152
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	15	22
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	9	9
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	0	0
Kentucky Utilities Co [Member] | Terminated Interest Rate Swap [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	38	41
Kentucky Utilities Co [Member] | Asset Retirement Obligations Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	173	141
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Noncurrent regulatory assets	$ 7	$ 9

Utility Rate Regulation (Regu67

Utility Rate Regulation (Regulatory Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 95	$ 101
Noncurrent regulatory liabilities	2,704	899
Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	34	23
Transmission Service Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	9	0
Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	26	14
Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	9	15
Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	11
Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8	13
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	677	700
Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	68	75
Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,853	23
Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	17
Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	27	23
Terminated Interest Rate Swap [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	74	78
Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	8
Noncurrent regulatory liabilities	5	0
PPL Electric Utilities Corp [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	86	83
Noncurrent regulatory liabilities	668	0
PPL Electric Utilities Corp [Member] | Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	34	23
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	9	0
PPL Electric Utilities Corp [Member] | Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	26	14
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	9	15
PPL Electric Utilities Corp [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8	13
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	668	0
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	17
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Terminated Interest Rate Swap [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	1
Noncurrent regulatory liabilities	0	0
LG And E And KU Energy LLC [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	9	18
Noncurrent regulatory liabilities	2,036	899
LG And E And KU Energy LLC [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	3
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	11
LG And E And KU Energy LLC [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	3	0
LG And E And KU Energy LLC [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	677	700
LG And E And KU Energy LLC [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	68	75
LG And E And KU Energy LLC [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,185	23
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	27	23
LG And E And KU Energy LLC [Member] | Terminated Interest Rate Swap [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	74	78
LG And E And KU Energy LLC [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	4
Noncurrent regulatory liabilities	5	0
Louisville Gas And Electric Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	5
Noncurrent regulatory liabilities	919	419
Louisville Gas And Electric Co [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	2
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	2
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	3	0
Louisville Gas And Electric Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	282	305
Louisville Gas And Electric Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	47	52
Louisville Gas And Electric Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	552	23
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
Louisville Gas And Electric Co [Member] | Terminated Interest Rate Swap [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	37	39
Louisville Gas And Electric Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	1
Noncurrent regulatory liabilities	1	0
Kentucky Utilities Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	13
Noncurrent regulatory liabilities	1,117	480
Kentucky Utilities Co [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	1
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	9
Kentucky Utilities Co [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Kentucky Utilities Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	395	395
Kentucky Utilities Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	21	23
Kentucky Utilities Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	633	0
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	27	23
Kentucky Utilities Co [Member] | Terminated Interest Rate Swap [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	37	39
Kentucky Utilities Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	3
Noncurrent regulatory liabilities	$ 4	$ 0

Utility Rate Regulation (Regu68

Utility Rate Regulation (Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities		$ 12	$ 59	$ (42)
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 2	(9)	(101)
Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		15 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset and liability balances expected to be amortized into net periodic defined benefit costs in the next year		$ 68
Regulatory Asset Amortization Period		15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period to be recorded as a regulatory asset in the following year		$ 16
Unamortized Loss On Debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2044
Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Mar. 31, 2026
Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities		$ 2,185
PPL Electric [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
Regulatory Assets and Liabilities - Storm Costs (Numeric) [Abstract]
Period over which storm costs will be recovered (in years)		3 years
PPL Electric [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		5 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		5 years
PPL Electric [Member] | Storm Damage Expense Rider [Member]
Regulatory Assets and Liabilities - Storm Damage Expense Rider (Numeric) [Abstract]
Maximum reportable storm damage expenses to be recovered annually through base rates		$ 15
Amount of amortized storm expense included in base rate component		5
PPL Electric [Member] | Act 129 Compliance Rider [Member]
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost		250
Maximum recoverable cost Phase II		$ 185
Period over which program costs can be recovered for Phase II (in years)		3 years
Maximum amount of costs that can be recovered under the Act 129 Phase III plan		$ 313
Period over which program costs can be recovered for Phase III (in years)		5 years
LKE [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 33	20
LGE [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
LGE [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
LGE [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2033
LGE [Member] | Terminated Interest Rate Swap [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		17 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		17 years
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps	$ 9
LGE [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity		9.70%
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program		5 years
LGE [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		18 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		18 months
LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Return on equity		9.70%
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
KU [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
KU [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Return on equity		9.70%
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
PPL Electric Utilities Corp [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		5 years
Increase (Decrease) in Regulatory Assets and Liabilities		$ 5	62	(35)
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		5 years
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum amount of costs that can be recovered under the Act 129 Phase III plan		$ 313
Period over which program costs can be recovered for Phase III (in years)		5 years
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset and liability balances expected to be amortized into net periodic defined benefit costs in the next year		$ 30
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
Regulatory Assets and Liabilities - Storm Costs (Numeric) [Abstract]
Period over which storm costs will be recovered (in years)		3 years
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2029
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		5 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		5 years
PPL Electric Utilities Corp [Member] | Storm Damage Expense Rider [Member]
Regulatory Assets and Liabilities - Storm Damage Expense Rider (Numeric) [Abstract]
Maximum reportable storm damage expenses to be recovered annually through base rates		$ 15
Amount of amortized storm expense included in base rate component		5
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost		250
Maximum recoverable cost Phase II		$ 185
Period over which program costs can be recovered for Phase II (in years)		3 years
Maximum amount of costs that can be recovered under the Act 129 Phase III plan		$ 313
Period over which program costs can be recovered for Phase III (in years)		5 years
PPL Electric Utilities Corp [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities		$ 1,019
LG And E And KU Energy LLC [Member]
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 0	(9)	(88)
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		15 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset and liability balances expected to be amortized into net periodic defined benefit costs in the next year		$ 38
Regulatory Asset Amortization Period		15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 33	20
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period to be recorded as a regulatory asset in the following year		$ 16
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2044
LG And E And KU Energy LLC [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Mar. 31, 2026
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities		$ 1,166
LG And E And KU Energy LLC [Member] | LGE [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
LG And E And KU Energy LLC [Member] | LGE [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
LG And E And KU Energy LLC [Member] | LGE [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2033
LG And E And KU Energy LLC [Member] | LGE [Member] | Terminated Interest Rate Swap [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		17 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		17 years
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps	(9)
LG And E And KU Energy LLC [Member] | LGE [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity		9.70%
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program		5 years
LG And E And KU Energy LLC [Member] | LGE [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		18 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		18 months
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Return on equity		9.70%
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
LG And E And KU Energy LLC [Member] | KU [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
LG And E And KU Energy LLC [Member] | KU [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
LG And E And KU Energy LLC [Member] | KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Return on equity		9.70%
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
Louisville Gas And Electric Co [Member]
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 0	(9)	(44)
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		15 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset and liability balances expected to be amortized into net periodic defined benefit costs in the next year		$ 26
Regulatory Asset Amortization Period		15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 18	11
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period to be recorded as a regulatory asset in the following year		$ 10
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2044
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2033
Louisville Gas And Electric Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Mar. 31, 2026
Louisville Gas And Electric Co [Member] | Terminated Interest Rate Swap [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		17 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		17 years
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps	$ 9
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity		9.70%
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program		5 years
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		18 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		18 months
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Return on equity		9.70%
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities		$ 532
Kentucky Utilities Co [Member]
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 0	0	$ (44)
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		15 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset and liability balances expected to be amortized into net periodic defined benefit costs in the next year		$ 12
Regulatory Asset Amortization Period		15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 15	$ 9
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period to be recorded as a regulatory asset in the following year		$ 6
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2042
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Kentucky Utilities Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Mar. 31, 2026
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		12 months
Return on equity		9.70%
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory Asset Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity		9.70%
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities		$ 634

Utility Rate Regulation (Regu69

Utility Rate Regulation (Regulatory Matters) (Details) $ in Millions	Jan. 29, 2018USD ($)	Jan. 10, 2018USD ($)	Jun. 23, 2017	Jun. 30, 2017USD ($)	May 31, 2017USD ($)	Aug. 31, 2016	Dec. 31, 2017USD ($)Integer
Regulatory Matters - United Kingdom Activities - Ofgem Review of Line Loss Calculation (Numeric) [Abstract]
Number Of Distribution Network Operators | Integer							4
PPL Electric [Member] | Act 129 Compliance Rider [Member]
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract]
Minimum term of long term supply contract under Act 129 (in years)							4 years
Maximum term of long term supply contract under Act 129 (in years)							20 years
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129							25.00%
Maximum amount of costs that can be recovered under the Act 129 Phase III plan							$ 313
Period over which program costs can be recovered (in years)							5 years
LKE [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Depreciation Rate Increase (Decrease)				$ 15
LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans			10.00%
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings			9.80%
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects			9.70%
Return on equity							9.70%
Amortization period for the deferred recovery of a regulatory asset							12 months
LGE [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				5.20%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 59
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 57
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 59
LGE [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				2.10%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 8
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 7
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 8
LGE [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	$ 69
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	69
LGE [Member] | Subsequent Event [Member] | Gas Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	17
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	17
LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service		$ 104
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service		11
LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Gas Service		62
Advanced Metering Systems Deployment Incremental O&M Cost, Gas Service		3
KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans			10.00%
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings			9.80%
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects			9.70%
Return on equity							9.70%
Amortization period for the deferred recovery of a regulatory asset							12 months
KU [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				3.20%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 55
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 52
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 55
KU [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	91
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	91
KU [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service		155
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service		17
PPL Electric Utilities Corp [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Amortization period for the deferred recovery of a regulatory asset							5 years
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract]
Minimum term of long term supply contract under Act 129 (in years)							4 years
Maximum term of long term supply contract under Act 129 (in years)							20 years
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129							25.00%
Maximum amount of costs that can be recovered under the Act 129 Phase III plan							$ 313
Period over which program costs can be recovered (in years)							5 years
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract]
Maximum amount of costs that can be recovered under the Act 129 Phase III plan							$ 313
Period over which program costs can be recovered (in years)							5 years
LG And E And KU Energy LLC [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Depreciation Rate Increase (Decrease)				$ 15
LG And E And KU Energy LLC [Member] | LGE [Member]
Regulatory Matters - Kentucky Activities - Gas Franchise (Numeric) [Abstract]
Franchise Agreement Term						5 years
Days of Notice to Modify Franchise Fee						60 days
Franchise Fee Cap						3.00%
Franchise Fee If Recovered From Customers						0.00%
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans			10.00%
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings			9.80%
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects			9.70%
Return on equity							9.70%
Amortization period for the deferred recovery of a regulatory asset							12 months
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				5.20%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 59
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 57
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 59
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				2.10%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 8
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 7
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 8
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	69
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	69
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Gas Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	17
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	17
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service		104
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service		11
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Gas Service		62
Advanced Metering Systems Deployment Incremental O&M Cost, Gas Service		3
LG And E And KU Energy LLC [Member] | KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans			10.00%
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings			9.80%
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects			9.70%
Return on equity							9.70%
Amortization period for the deferred recovery of a regulatory asset							12 months
LG And E And KU Energy LLC [Member] | KU [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				3.20%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 55
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 52
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 55
LG And E And KU Energy LLC [Member] | KU [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	91
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	91
LG And E And KU Energy LLC [Member] | KU [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service		155
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service		17
Louisville Gas And Electric Co [Member]
Regulatory Matters - Kentucky Activities - Gas Franchise (Numeric) [Abstract]
Franchise Agreement Term						5 years
Days of Notice to Modify Franchise Fee						60 days
Franchise Fee Cap						3.00%
Franchise Fee If Recovered From Customers						0.00%
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans			10.00%
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings			9.80%
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects			9.70%
Return on equity							9.70%
Amortization period for the deferred recovery of a regulatory asset							12 months
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				5.20%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 59
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 57
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 59
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				2.10%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 8
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 7
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 8
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Depreciation Rate Increase (Decrease)				$ 4
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	69
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	69
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Gas Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	17
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	17
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service		104
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service		11
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Gas Service		62
Advanced Metering Systems Deployment Incremental O&M Cost, Gas Service		3
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans			10.00%
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings			9.80%
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects			9.70%
Return on equity							9.70%
Amortization period for the deferred recovery of a regulatory asset							12 months
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Rate Increase (Decrease), Percentage				3.20%
Public Utilities Proposed Return On Equity Percentage					9.75%
Public Utilities Proposed Rate Increase Decrease Amount					$ 55
Increase in annual revenue requirements associated with base rates resulting from rate case				$ 52
Return on equity				9.70%
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount					$ 55
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Approved Depreciation Rate Increase (Decrease)				$ 11
Kentucky Utilities Co [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	91
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract]
Public Utilities Proposed Rate Increase Decrease Amount	$ 91
Kentucky Utilities Co [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member]
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract]
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service		155
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service		$ 17

Utility Rate Regulation Utility

Utility Rate Regulation Utility Rate Regulation (Other) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
PPL Electric [Member] | Unaffiliated Third Party Entity [Member]
Purchases Of Accounts Receivable [Line Items]
Purchases of accounts receivable	$ 1,300	$ 1,400	$ 1,300
PPL Electric Utilities Corp [Member] | Unaffiliated Third Party Entity [Member]
Purchases Of Accounts Receivable [Line Items]
Purchases of accounts receivable	$ 1,300	$ 1,400	1,300
PPL Electric Utilities Corp [Member] | PPL EnergyPlus [Member]
Purchases Of Accounts Receivable [Line Items]
Purchases of accounts receivable			$ 146

Financing Activities (Credit Ar

Financing Activities (Credit Arrangements) (Details) £ in Millions, $ in Millions	1 Months Ended		12 Months Ended
	Jan. 31, 2018USD ($)	Oct. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017GBP (£)	Dec. 31, 2016USD ($)	Dec. 31, 2016GBP (£)
U.K. [Member]
Financing Activities [Line Items]
Capacity | £				£ 1,155
Borrowed | £				448		£ 339
Letters of credit and commercial paper issued | £				4		4
Unused capacity			$ 949	701
U.K. [Member] | Uncommitted Credit Facilities [Member]
Financing Activities [Line Items]
Capacity | £				100
Borrowed | £				0		60
Letters of credit and commercial paper issued | £				4		4
Unused capacity | £				96
WPD PLC [Member] | U.K. [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity | £				210
Borrowed			$ 200	148	$ 200	160
Letters of credit and commercial paper issued | £				0		£ 0
Unused capacity | £				£ 60
Minimum interest coverage ratio allowed under the credit facility			3.0 times
Maximum percentage of total net debt to RAV allowed under the credit facility			85.00%	85.00%
Interest rate on outstanding borrowing			2.17%	2.17%	1.43%	1.43%
Borrowed | £				£ 150
WPD South West [Member] | U.K. [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jul. 31, 2021
Capacity | £				245
Borrowed | £				0		£ 110
Letters of credit and commercial paper issued | £				0		0
Unused capacity | £				£ 245
Minimum interest coverage ratio allowed under the credit facility			3.0 times
Maximum percentage of total net debt to RAV allowed under the credit facility			85.00%	85.00%
WPD East Midlands [Member] | U.K. [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jul. 31, 2021
Capacity | £				£ 300
Borrowed			$ 244	180		9
Letters of credit and commercial paper issued | £				0		0
Unused capacity | £				£ 120
Minimum interest coverage ratio allowed under the credit facility			3.0 times
Maximum percentage of total net debt to RAV allowed under the credit facility			85.00%	85.00%
Interest rate on outstanding borrowing			0.89%	0.89%
WPD West Midlands [Member] | U.K. [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jul. 31, 2021
Capacity | £				£ 300
Borrowed			$ 162	120		0
Letters of credit and commercial paper issued | £				0		£ 0
Unused capacity | £				£ 180
Minimum interest coverage ratio allowed under the credit facility			3.0 times
Maximum percentage of total net debt to RAV allowed under the credit facility			85.00%	85.00%
Interest rate on outstanding borrowing			0.89%	0.89%
PPL Capital Funding [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
PPL Capital Funding [Member] | U.S. [Member]
Financing Activities [Line Items]
Capacity			$ 1,400
Borrowed			0		$ 0
Letters of credit and commercial paper issued			248		37
Unused capacity			$ 1,152
PPL Capital Funding [Member] | U.S. [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 950
Borrowed			0		0
Letters of credit and commercial paper issued			230		20
Unused capacity			$ 720
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
PPL Capital Funding [Member] | U.S. [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
PPL Capital Funding [Member] | U.S. [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Nov. 30, 2018
Capacity			$ 300
Borrowed			0		0
Letters of credit and commercial paper issued			0		0
Unused capacity			$ 300
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 30
PPL Capital Funding [Member] | U.S. [Member] | Bilateral Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Mar. 31, 2018
Capacity			$ 150
Borrowed			0		0
Letters of credit and commercial paper issued			18		17
Unused capacity			$ 132
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 30
PPL Electric [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 650
Borrowed			0		0
Letters of credit and commercial paper issued			1		296
Unused capacity			$ 649
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
PPL Electric [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
LKE [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Oct. 31, 2018
Capacity			$ 75
Borrowed			0		0
Letters of credit and commercial paper issued			0		0
Unused capacity			$ 75
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 25
LGE [Member]
Financing Activities [Line Items]
Capacity			700
Borrowed			100		0
Letters of credit and commercial paper issued			199		169
Unused capacity			$ 401
LGE [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 500
Borrowed			0		0
Letters of credit and commercial paper issued			199		169
Unused capacity			$ 301
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
LGE [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
LGE [Member] | Term Loan Credit Facility [Member]
Financing Activities [Line Items]
Expiration date		Oct. 31, 2019	Oct. 31, 2019
Capacity		$ 200	$ 200
Borrowed			100		0
Letters of credit and commercial paper issued			0		0
Unused capacity			$ 100
Interest rate on outstanding borrowing			2.06%	2.06%
LGE [Member] | Term Loan Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Borrowed	$ 100
KU [Member]
Financing Activities [Line Items]
Capacity			$ 598
Borrowed			0		0
Letters of credit and commercial paper issued			243		214
Unused capacity			$ 355
KU [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 400
Borrowed			0		0
Letters of credit and commercial paper issued			45		16
Unused capacity			$ 355
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
KU [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
KU [Member] | Letter Of Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Oct. 31, 2020
Capacity			$ 198
Borrowed			0		0
Letters of credit and commercial paper issued			198		198
Unused capacity			$ 0
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
PPL Electric Utilities Corp [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 650
Borrowed			0		0
Letters of credit and commercial paper issued			1		296
Unused capacity			$ 649
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
PPL Electric Utilities Corp [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
LG And E And KU Energy LLC [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Oct. 31, 2018
Capacity			$ 75
Borrowed			0		0
Letters of credit and commercial paper issued			0		0
Unused capacity			$ 75
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 25
LG And E And KU Energy LLC [Member] | LGE [Member]
Financing Activities [Line Items]
Capacity			700
Borrowed			100		0
Letters of credit and commercial paper issued			199		169
Unused capacity			$ 401
LG And E And KU Energy LLC [Member] | LGE [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 500
Borrowed			0		0
Letters of credit and commercial paper issued			199		169
Unused capacity			$ 301
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
LG And E And KU Energy LLC [Member] | LGE [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
LG And E And KU Energy LLC [Member] | LGE [Member] | Term Loan Credit Facility [Member]
Financing Activities [Line Items]
Expiration date		Oct. 31, 2019	Oct. 31, 2019
Capacity		$ 200	$ 200
Borrowed			100		0
Letters of credit and commercial paper issued			0		0
Unused capacity			$ 100
Interest rate on outstanding borrowing			2.06%	2.06%
LG And E And KU Energy LLC [Member] | LGE [Member] | Term Loan Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Borrowed	$ 100
LG And E And KU Energy LLC [Member] | KU [Member]
Financing Activities [Line Items]
Capacity			$ 598
Borrowed			0		0
Letters of credit and commercial paper issued			243		214
Unused capacity			$ 355
LG And E And KU Energy LLC [Member] | KU [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 400
Borrowed			0		0
Letters of credit and commercial paper issued			45		16
Unused capacity			$ 355
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
LG And E And KU Energy LLC [Member] | KU [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
LG And E And KU Energy LLC [Member] | KU [Member] | Letter Of Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Oct. 31, 2020
Capacity			$ 198
Borrowed			0		0
Letters of credit and commercial paper issued			198		198
Unused capacity			$ 0
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
Louisville Gas And Electric Co [Member]
Financing Activities [Line Items]
Capacity			700
Borrowed			100		0
Letters of credit and commercial paper issued			199		169
Unused capacity			$ 401
Louisville Gas And Electric Co [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 500
Borrowed			0		0
Letters of credit and commercial paper issued			199		169
Unused capacity			$ 301
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
Louisville Gas And Electric Co [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
Louisville Gas And Electric Co [Member] | Term Loan Credit Facility [Member]
Financing Activities [Line Items]
Expiration date		Oct. 31, 2019	Oct. 31, 2019
Capacity		$ 200	$ 200
Borrowed			100		0
Letters of credit and commercial paper issued			0		0
Unused capacity			$ 100
Interest rate on outstanding borrowing			2.06%	2.06%
Louisville Gas And Electric Co [Member] | Term Loan Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Borrowed	$ 100
Kentucky Utilities Co [Member]
Financing Activities [Line Items]
Capacity			$ 598
Borrowed			0		0
Letters of credit and commercial paper issued			243		214
Unused capacity			$ 355
Kentucky Utilities Co [Member] | Syndicated Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Jan. 31, 2022
Capacity			$ 400
Borrowed			0		0
Letters of credit and commercial paper issued			45		16
Unused capacity			$ 355
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100
Kentucky Utilities Co [Member] | Syndicated Credit Facility [Member] | Subsequent Event [Member]
Financing Activities [Line Items]
Expiration date	Jan. 31, 2023
Kentucky Utilities Co [Member] | Letter Of Credit Facility [Member]
Financing Activities [Line Items]
Expiration date			Oct. 31, 2020
Capacity			$ 198
Borrowed			0		0
Letters of credit and commercial paper issued			198		$ 198
Unused capacity			$ 0
Maximum percentage of debt to total capitalization allowed under the credit facility			70.00%	70.00%
Potential capacity increase			$ 100

Financing Activities (Short-ter

Financing Activities (Short-term Debt) (Details) - Commercial Paper [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Capacity	$ 2,350
Commercial paper issuances	474	$ 500
Unused capacity	$ 1,876
PPL Capital Funding [Member]
Short-term Debt [Line Items]
Weighted-average interest rate	1.64%	1.10%
Capacity	$ 1,000
Commercial paper issuances	230	$ 20
Unused capacity	$ 770
PPL Electric [Member]
Short-term Debt [Line Items]
Weighted-average interest rate		1.05%
Capacity	$ 650
Commercial paper issuances	0	$ 295
Unused capacity	$ 650
LGE [Member]
Short-term Debt [Line Items]
Weighted-average interest rate	1.83%	0.94%
Capacity	$ 350
Commercial paper issuances	199	$ 169
Unused capacity	$ 151
KU [Member]
Short-term Debt [Line Items]
Weighted-average interest rate	1.97%	0.87%
Capacity	$ 350
Commercial paper issuances	45	$ 16
Unused capacity	$ 305
PPL Electric Utilities Corp [Member]
Short-term Debt [Line Items]
Weighted-average interest rate		1.05%
Capacity	$ 650
Commercial paper issuances	0	$ 295
Unused capacity	$ 650
LG And E And KU Energy LLC [Member] | LGE [Member]
Short-term Debt [Line Items]
Weighted-average interest rate	1.83%	0.94%
Capacity	$ 350
Commercial paper issuances	199	$ 169
Unused capacity	$ 151
LG And E And KU Energy LLC [Member] | KU [Member]
Short-term Debt [Line Items]
Weighted-average interest rate	1.97%	0.87%
Capacity	$ 350
Commercial paper issuances	45	$ 16
Unused capacity	$ 305
Louisville Gas And Electric Co [Member]
Short-term Debt [Line Items]
Weighted-average interest rate	1.83%	0.94%
Capacity	$ 350
Commercial paper issuances	199	$ 169
Unused capacity	$ 151
Kentucky Utilities Co [Member]
Short-term Debt [Line Items]
Weighted-average interest rate	1.97%	0.87%
Capacity	$ 350
Commercial paper issuances	45	$ 16
Unused capacity	$ 305

Financing Activities (Long-term

Financing Activities (Long-term Debt and Equity Securities) (Details) shares in Thousands, £ in Millions, $ in Millions	1 Months Ended											3 Months Ended		9 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)	Nov. 30, 2017USD ($)	Nov. 30, 2017GBP (£)	Oct. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Aug. 31, 2017USD ($)	Jun. 30, 2017USD ($)	May 31, 2017USD ($)	Apr. 30, 2017USD ($)	Mar. 31, 2016	Feb. 28, 2015USD ($)Integer	Mar. 31, 2017USD ($)	Mar. 31, 2017GBP (£)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares	Jan. 31, 2018USD ($)	Dec. 31, 2017GBP (£)	Dec. 31, 2016GBP (£)
Debt Instrument [Line Items]
Principal outstanding	$ 20,282														$ 20,282	$ 18,399
Less current portion of Long-term debt	348														348	518
Long-term Debt	19,847														19,847	17,808
Aggregate maturities of long-term debt (Details) [Abstract]
2,018	348														348
2,019	430														430
2,020	1,278														1,278
2,021	1,150														1,150
2,022	1,274														1,274
Thereafter	15,802														15,802
Equity Programs (Numeric) [Abstract]
Net proceeds from issuance of common stock															$ 453	144	$ 203
WPD [Member] | Senior Secured Notes [Member]
Debt Instrument [Line Items]
Repayments of Senior Debt	$ 100
Long-term Debt (Numeric) [Abstract]
Stated interest rate	7.25%														7.25%				7.25%
WPD South West [Member] | Senior Secured Notes [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount		$ 250
Stated interest rate		2.375%
Maturity date (in years)		Dec. 31, 2029	Dec. 31, 2029
Proceeds from debt, including premium net of debt issuance costs		$ 326	£ 247
WPD South West [Member] | Index Linked Senior Unsecured Notes [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount that may be redeemed in total by series	$ 304														$ 304				£ 225
Earliest date the company may redeem the debt in total by series															Dec. 1, 2026
Increase (decrease) in principal due to inflation	37														$ 37				27
WPD South Wales [Member] | Index Linked Senior Unsecured Notes [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount | £													£ 50
Stated interest rate													0.01%
Maturity date (in years)												Dec. 31, 2029	Dec. 31, 2029
Proceeds from Debt, Net of Issuance Costs | £													£ 53
Proceeds from debt, including premium net of debt issuance costs												$ 64
Increase (decrease) in principal due to inflation	37														37				27
WPD East Midlands [Member] | Index Linked Senior Unsecured Notes [Member]
Long-term Debt (Numeric) [Abstract]
Increase (decrease) in principal due to inflation	37														37				£ 27
PPL Capital Funding [Member] | Senior Secured Notes [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount					$ 500									$ 500
Stated interest rate					4.00%									4.00%
Maturity date (in years)														Dec. 31, 2047
Proceeds from debt, including premium net of debt issuance costs														$ 490
PPL Electric [Member] | Senior Secured Notes [Member] | Lehigh County Industrial Development Authority Pollution Control Revenue Refunding Bonds Series 2016B [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount						$ 108
Stated interest rate						1.80%
Maturity date (in years)						Dec. 31, 2027
Debt Instruments Future Repurchase Date						Aug. 15, 2022
PPL Electric [Member] | Senior Secured Notes [Member] | Lehigh County Industrial Development Authority Pollution Control Revenue Refunding Bonds Series 2016A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount					$ 116									$ 116
Stated interest rate					1.80%									1.80%
Maturity date (in years)					Dec. 31, 2029
Debt Instruments Future Repurchase Date					Sep. 1, 2022
PPL Electric [Member] | Senior Secured Notes - First Mortgage Bonds [Member] | Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	8,500														8,500	7,600
PPL Electric [Member] | Senior Secured Notes - First Mortgage Bonds [Member] | Pollution Control Revenue Refunding Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount that may be redeemed at a future date	224														224
Principal amount that may be redeemed in whole or in part	90														$ 90
Earliest date the company may redeem the debt in whole or in part															Oct. 31, 2020
Minimum length of time to convert interest rate mode															1 year
PPL Electric [Member] | First Mortgage Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount								$ 475
Stated interest rate								3.95%
Maturity date (in years)								Dec. 31, 2047
Proceeds from Debt, Net of Issuance Costs								$ 466
LGE [Member]
Long-term Debt (Numeric) [Abstract]
Capacity	700														$ 700
Borrowed	$ 100														$ 100	0
LGE [Member] | Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Expiration date				Oct. 31, 2019											Oct. 31, 2019
Interest rate on outstanding borrowing	2.06%														2.06%				2.06%
Long-term Debt (Numeric) [Abstract]
Capacity	$ 200			$ 200											$ 200
Borrowed	100														100	0
LGE [Member] | Term Loan Credit Facility [Member] | Subsequent Event [Member]
Long-term Debt (Numeric) [Abstract]
Borrowed																		$ 100
LGE [Member] | Senior Secured Notes [Member] | Pollution Control Revenue Bonds, 2003 Series A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount									$ 128
Stated interest rate									1.50%
Maturity date (in years)									Dec. 31, 2033
Debt Instruments Future Repurchase Date									Apr. 1, 2019
LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2017 Series A [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 60
Stated interest rate							3.75%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 1, 2027
LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series A [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 60
Maturity date (in years)							Dec. 31, 2033
LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 31
Stated interest rate							1.25%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 3, 2019
LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series B [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 35
Stated interest rate							1.25%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 3, 2019
LGE [Member] | Senior Secured Notes [Member] | Louisville/Jefferson County Metro Government Environmental Facilities Revenue Bonds 2001 Series A [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount		$ 10
Maturity date (in years)		Dec. 31, 2027	Dec. 31, 2027
LGE [Member] | First Mortgage Bonds [Member] | 2010 Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	4,700														$ 4,700	4,400
LGE [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Minimum length of time to convert interest rate mode															1 year
LKE [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate amount of tax-exempt revenue bonds in a term rate mode	514														$ 514
Aggregate amount of tax-exempt revenue bonds in a variable rate mode	375														375
KU [Member]
Long-term Debt (Numeric) [Abstract]
Capacity	598														598
Borrowed	0														0	0
KU [Member] | First Mortgage Bonds [Member] | 2010 Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	6,000														$ 6,000	$ 5,800
KU [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Minimum length of time to convert interest rate mode															1 year
At The Market Stock Offering Program [Member]
Equity Programs (Numeric) [Abstract]
Shares of common stock issued during the period | shares															10,373	710	1,477
Net proceeds from issuance of common stock															$ 377	$ 25	$ 49
Maximum Percentage Paid To Selling Agents															1.00%
Number of distribution agreements | Integer											2
Aggregate sales price of common stock based on two separate equity distribution agreements											$ 500
U.S. [Member]
Debt Instrument [Line Items]
Principal outstanding	$ 12,919														$ 12,919	11,854
U.S. [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.78%														3.78%				3.78%
Maturity date of long-term debt range start															Dec. 31, 2020
Maturity date of long-term date range end															Dec. 31, 2047
Principal outstanding	$ 4,575														$ 4,575	4,075
U.S. [Member] | Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	2.06%														2.06%				2.06%
Maturity date of long-term date range end															Dec. 31, 2019
Principal outstanding	$ 100														$ 100	0
U.S. [Member] | Senior Secured Notes - First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.96%														3.96%				3.96%
Maturity date of long-term debt range start															Dec. 31, 2018
Maturity date of long-term date range end															Dec. 31, 2047
Principal outstanding	$ 7,314														$ 7,314	6,849
U.S. [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	5.10%														5.10%				5.10%
Maturity date of long-term debt range start															Dec. 31, 2067
Maturity date of long-term date range end															Dec. 31, 2073
Principal outstanding	$ 930														$ 930	930
U.S. [Member] | PPL Capital Funding [Member]
Long-term Debt (Numeric) [Abstract]
Capacity	1,400														1,400
Borrowed	0														0	0
U.K. [Member]
Debt Instrument [Line Items]
Principal outstanding	7,363														7,363	6,545
Fair market value adjustments	21														21	22
Unamortized premium and (discount), net	14														14	20
Unamortized debt issuance costs	(122)														(122)	(115)
Total Long-term Debt	20,195														20,195	18,326
Less current portion of Long-term debt	348														348	518
Long-term Debt	19,847														19,847	17,808
Long-term Debt (Numeric) [Abstract]
Principal amount that may be put back to the issuer	$ 6,400														$ 6,400				£ 4,700
Capacity | £																			1,155
Borrowed | £																			£ 448	£ 339
U.K. [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	5.24%														5.24%				5.24%
Maturity date of long-term debt range start															Dec. 31, 2020
Maturity date of long-term date range end															Dec. 31, 2040
Principal outstanding	$ 6,351														$ 6,351	5,707
Long-term Debt (Numeric) [Abstract]
Principal amount that may be redeemed in total but not in part	$ 304														$ 304				£ 225
Earliest date the company may redeem the debt in total but not in part															Dec. 21, 2026
U.K. [Member] | Index Linked Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	1.56%														1.56%				1.56%
Maturity date of long-term debt range start															Dec. 31, 2026
Maturity date of long-term date range end															Dec. 31, 2056
Principal outstanding	$ 1,012														$ 1,012	838
PPL Electric Utilities Corp [Member]
Debt Instrument [Line Items]
Principal outstanding	3,339														3,339	2,864
Unamortized discount	(16)														(16)	(12)
Unamortized debt issuance costs	(25)														(25)	(21)
Total Long-term Debt	3,298														3,298	2,831
Less current portion of Long-term debt	0														0	224
Long-term Debt	3,298														3,298	2,607
Aggregate maturities of long-term debt (Details) [Abstract]
2,018	0														0
2,019	0														0
2,020	100														100
2,021	400														400
2,022	474														474
Thereafter	$ 2,365														$ 2,365
PPL Electric Utilities Corp [Member] | Senior Secured Notes [Member] | Lehigh County Industrial Development Authority Pollution Control Revenue Refunding Bonds Series 2016B [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount						$ 108
Stated interest rate						1.80%
Maturity date (in years)						Dec. 31, 2027
Debt Instruments Future Repurchase Date						Aug. 15, 2022
PPL Electric Utilities Corp [Member] | Senior Secured Notes [Member] | Lehigh County Industrial Development Authority Pollution Control Revenue Refunding Bonds Series 2016A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount					$ 116									$ 116
Stated interest rate					1.80%									1.80%
Maturity date (in years)					Dec. 31, 2029
Debt Instruments Future Repurchase Date					Sep. 1, 2022
PPL Electric Utilities Corp [Member] | Senior Secured Notes - First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	4.23%														4.23%				4.23%
Maturity date of long-term debt range start															Dec. 31, 2020
Maturity date of long-term date range end															Dec. 31, 2047
Principal outstanding	$ 3,339														$ 3,339	2,864
PPL Electric Utilities Corp [Member] | Senior Secured Notes - First Mortgage Bonds [Member] | Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	8,500														8,500	7,600
PPL Electric Utilities Corp [Member] | Senior Secured Notes - First Mortgage Bonds [Member] | Pollution Control Revenue Refunding Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount that may be redeemed at a future date	224														224
Principal amount that may be redeemed in whole or in part	90														$ 90
Earliest date the company may redeem the debt in whole or in part															Oct. 31, 2020
Minimum length of time to convert interest rate mode															1 year
PPL Electric Utilities Corp [Member] | First Mortgage Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount								$ 475
Stated interest rate								3.95%
Maturity date (in years)										Dec. 31, 2047
Proceeds from Debt, Net of Issuance Costs								$ 466
LG And E And KU Energy LLC [Member]
Debt Instrument [Line Items]
Principal outstanding	5,200														$ 5,200	5,110
Fair market value adjustments	0														0	(1)
Unamortized discount	(14)														(14)	(15)
Unamortized debt issuance costs	(27)														(27)	(29)
Total Long-term Debt	5,159														5,159	5,065
Less current portion of Long-term debt	98														98	194
Long-term Debt	5,061														5,061	4,871
Aggregate maturities of long-term debt (Details) [Abstract]
2,018	98														98
2,019	430														430
2,020	975														975
2,021	250														250
2,022	0														0
Thereafter	$ 3,447														$ 3,447
LG And E And KU Energy LLC [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.97%														3.97%				3.97%
Maturity date of long-term debt range start															Dec. 31, 2020
Maturity date of long-term date range end															Dec. 31, 2021
Principal outstanding	$ 725														$ 725	725
LG And E And KU Energy LLC [Member] | Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	2.06%														2.06%				2.06%
Maturity date of long-term date range end															Dec. 31, 2019
Principal outstanding	$ 100														$ 100	0
LG And E And KU Energy LLC [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.73%														3.73%				3.73%
Maturity date of long-term debt range start															Dec. 31, 2018
Maturity date of long-term date range end															Dec. 31, 2045
Principal outstanding	$ 3,975														$ 3,975	3,985
LG And E And KU Energy LLC [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate amount of tax-exempt revenue bonds in a term rate mode	514														514
Aggregate amount of tax-exempt revenue bonds in a variable rate mode	$ 375														$ 375
LG And E And KU Energy LLC [Member] | Note Payable [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.50%														3.50%				3.50%
Maturity date of long-term date range end															Dec. 31, 2026
Principal outstanding	$ 400														$ 400	400
LG And E And KU Energy LLC [Member] | LGE [Member]
Long-term Debt (Numeric) [Abstract]
Capacity	700														700
Borrowed	$ 100														$ 100	0
LG And E And KU Energy LLC [Member] | LGE [Member] | Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Expiration date				Oct. 31, 2019											Oct. 31, 2019
Interest rate on outstanding borrowing	2.06%														2.06%				2.06%
Long-term Debt (Numeric) [Abstract]
Capacity	$ 200			$ 200											$ 200
Borrowed	100														100	0
LG And E And KU Energy LLC [Member] | LGE [Member] | Term Loan Credit Facility [Member] | Subsequent Event [Member]
Long-term Debt (Numeric) [Abstract]
Borrowed																		100
LG And E And KU Energy LLC [Member] | LGE [Member] | Senior Secured Notes [Member] | Pollution Control Revenue Bonds, 2003 Series A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount									$ 128
Stated interest rate									1.50%
Maturity date (in years)									Dec. 31, 2033
Debt Instruments Future Repurchase Date									Apr. 1, 2019
LG And E And KU Energy LLC [Member] | LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2017 Series A [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 60
Stated interest rate							3.75%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 1, 2027
LG And E And KU Energy LLC [Member] | LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series A [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 60
Maturity date (in years)							Dec. 31, 2033
LG And E And KU Energy LLC [Member] | LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 31
Stated interest rate							1.25%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 3, 2019
LG And E And KU Energy LLC [Member] | LGE [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series B [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 35
Stated interest rate							1.25%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 3, 2019
LG And E And KU Energy LLC [Member] | LGE [Member] | Senior Secured Notes [Member] | Louisville/Jefferson County Metro Government Environmental Facilities Revenue Bonds 2001 Series A [Member] [Domain]
Long-term Debt (Numeric) [Abstract]
Principal amount		$ 10
Maturity date (in years)		Dec. 31, 2027	Dec. 31, 2027
LG And E And KU Energy LLC [Member] | LGE [Member] | First Mortgage Bonds [Member] | 2010 Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	4,700														$ 4,700	4,400
LG And E And KU Energy LLC [Member] | LGE [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Minimum length of time to convert interest rate mode															1 year
LG And E And KU Energy LLC [Member] | KU [Member]
Long-term Debt (Numeric) [Abstract]
Capacity	598														$ 598
Borrowed	0														0	0
LG And E And KU Energy LLC [Member] | KU [Member] | First Mortgage Bonds [Member] | 2010 Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	6,000														$ 6,000	5,800
LG And E And KU Energy LLC [Member] | KU [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Minimum length of time to convert interest rate mode															1 year
Louisville Gas And Electric Co [Member]
Debt Instrument [Line Items]
Principal outstanding	1,724														$ 1,724	1,634
Fair market value adjustments	0														0	(1)
Unamortized discount	(4)														(4)	(4)
Unamortized debt issuance costs	(11)														(11)	(12)
Total Long-term Debt	1,709														1,709	1,617
Less current portion of Long-term debt	98														98	194
Long-term Debt	1,611														1,611	1,423
Long-term Debt (Numeric) [Abstract]
Capacity	700														700
Borrowed	100														100	0
Aggregate maturities of long-term debt (Details) [Abstract]
2,018	98														98
2,019	334														334
2,020	0														0
2,021	0														0
2,022	0														0
Thereafter	$ 1,292														$ 1,292
Louisville Gas And Electric Co [Member] | Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Expiration date				Oct. 31, 2019											Oct. 31, 2019
Interest rate on outstanding borrowing	2.06%														2.06%				2.06%
Long-term Debt (Numeric) [Abstract]
Capacity	$ 200			$ 200											$ 200
Borrowed	$ 100														$ 100	0
Louisville Gas And Electric Co [Member] | Term Loan Credit Facility [Member] | Subsequent Event [Member]
Long-term Debt (Numeric) [Abstract]
Borrowed																		$ 100
Louisville Gas And Electric Co [Member] | Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	2.06%														2.06%				2.06%
Maturity date of long-term date range end															Dec. 31, 2019
Principal outstanding	$ 100														$ 100	0
Louisville Gas And Electric Co [Member] | Senior Secured Notes [Member] | Pollution Control Revenue Bonds, 2003 Series A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount									$ 128
Stated interest rate									1.50%
Maturity date (in years)									Dec. 31, 2033
Debt Instruments Future Repurchase Date									Apr. 1, 2019
Louisville Gas And Electric Co [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2017 Series A [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 60
Stated interest rate							3.75%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 1, 2027
Louisville Gas And Electric Co [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series A [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 60
Maturity date (in years)							Dec. 31, 2033
Louisville Gas And Electric Co [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series A [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 31
Stated interest rate							1.25%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 3, 2019
Louisville Gas And Electric Co [Member] | Senior Secured Notes [Member] | Environmental Facilities Revenue Refunding Bonds, 2007 Series B [Member] | Remarketed [Member]
Long-term Debt (Numeric) [Abstract]
Principal amount							$ 35
Stated interest rate							1.25%
Maturity date (in years)							Dec. 31, 2033
Debt Instruments Future Repurchase Date							Jun. 3, 2019
Louisville Gas And Electric Co [Member] | Senior Secured Notes [Member] | Louisville/Jefferson County Metro Government Environmental Facilities Revenue Bonds 2001 Series A [Member] [Domain]
Long-term Debt (Numeric) [Abstract]
Principal amount		$ 10
Maturity date (in years)		Dec. 31, 2027	Dec. 31, 2027
Louisville Gas And Electric Co [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.48%														3.48%				3.48%
Maturity date of long-term debt range start															Dec. 31, 2018
Maturity date of long-term date range end															Dec. 31, 2045
Principal outstanding	$ 1,624														$ 1,624	1,634
Louisville Gas And Electric Co [Member] | First Mortgage Bonds [Member] | 2010 Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	4,700														$ 4,700	4,400
Louisville Gas And Electric Co [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Minimum length of time to convert interest rate mode															1 year
Aggregate amount of tax-exempt revenue bonds in a term rate mode	391														$ 391
Aggregate amount of tax-exempt revenue bonds in a variable rate mode	147														147
Kentucky Utilities Co [Member]
Debt Instrument [Line Items]
Principal outstanding	2,351														2,351	2,351
Unamortized discount	(9)														(9)	(9)
Unamortized debt issuance costs	(14)														(14)	(15)
Total Long-term Debt	2,328														2,328	2,327
Less current portion of Long-term debt	0														0	0
Long-term Debt	2,328														2,328	2,327
Long-term Debt (Numeric) [Abstract]
Capacity	598														598
Borrowed	0														0	0
Aggregate maturities of long-term debt (Details) [Abstract]
2,018	0														0
2,019	96														96
2,020	500														500
2,021	0														0
2,022	0														0
Thereafter	$ 1,755														$ 1,755
Kentucky Utilities Co [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Weighted-Average Rate	3.91%														3.91%				3.91%
Maturity date of long-term debt range start															Dec. 31, 2019
Maturity date of long-term date range end															Dec. 31, 2045
Principal outstanding	$ 2,351														$ 2,351	2,351
Kentucky Utilities Co [Member] | First Mortgage Bonds [Member] | 2010 Mortgage Indenture [Member]
Long-term Debt (Numeric) [Abstract]
Aggregate carrying value of property subject to lien	6,000														$ 6,000	$ 5,800
Kentucky Utilities Co [Member] | First Mortgage Bonds [Member] | Tax Exempt Revenue Bonds [Member]
Long-term Debt (Numeric) [Abstract]
Minimum length of time to convert interest rate mode															1 year
Aggregate amount of tax-exempt revenue bonds in a term rate mode	123														$ 123
Aggregate amount of tax-exempt revenue bonds in a variable rate mode	$ 228														$ 228

Financing Activities (Distribut

Financing Activities (Distributions and Capital Contributions) (Details) - USD ($) $ / shares in Units, $ in Billions	1 Months Ended		3 Months Ended								12 Months Ended
	Feb. 28, 2018	Nov. 30, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Distributions [Line Items]
Dividend payable date of quarterly common stock dividend		Jan. 2, 2018
Current quarterly common stock dividend (in dollars per share)		$ 0.395	$ 0.3950	$ 0.3950	$ 0.3950	$ 0.3950	$ 0.38	$ 0.38	$ 0.38	$ 0.38	$ 1.58	$ 1.52	$ 1.50
Annualized current quarterly common stock dividend (in dollars per share)		$ 1.58
Subsequent Event [Member]
Distributions [Line Items]
Current quarterly common stock dividend (in dollars per share)	$ 0.410
Annualized current quarterly common stock dividend (in dollars per share)	$ 1.64
LKE [Member]
Distributions [Line Items]
Restricted net assets at end of period			$ 2.7								$ 2.7
Unrestricted assets at the end of period			3.1								$ 3.1
Minimum adjusted equity to total capitalization in order to pay dividends											30.00%
LG And E And KU Energy LLC [Member]
Distributions [Line Items]
Restricted net assets at end of period			2.7								$ 2.7
Unrestricted assets at the end of period			3.1								$ 3.1
Minimum adjusted equity to total capitalization in order to pay dividends											30.00%
Louisville Gas And Electric Co [Member]
Distributions [Line Items]
Restricted net assets at end of period			1.1								$ 1.1
Unrestricted assets at the end of period			1.4								$ 1.4
Minimum adjusted equity to total capitalization in order to pay dividends											30.00%
Kentucky Utilities Co [Member]
Distributions [Line Items]
Restricted net assets at end of period			1.6								$ 1.6
Unrestricted assets at the end of period			$ 1.7								$ 1.7
Minimum adjusted equity to total capitalization in order to pay dividends											30.00%

Acquisitions, Development and75

Acquisitions, Development and Divestures (Details) $ in Millions	Jun. 01, 2015USD ($)shares	Jun. 30, 2016USD ($)MW	Sep. 30, 2015USD ($)coal-fired_unit	Jun. 30, 2015USD ($)Integercoal-fired_unit	Mar. 31, 2015coal-fired_unit	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)kVIntegercoal-fired_unitmi	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Continuing Involvement (Details) [Abstract]
Energy purchases							$ 685	$ 706	$ 855
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Results of Discontinued Operations (Details) [Abstract]
Income tax expense (benefit)							0	0	(30)
Loss from Discontinued Operations (net of income taxes)							$ 0	0	(921)
PPL Energy Supply Spinoff [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Spinoff agreement execution date				Jun. 9, 2014
Date of record				May 20, 2015
Effective date of spinoff				Jun. 1, 2015
Certain details of spinoff transaction							In June 2014, PPL and PPL Energy Supply executed definitive agreements with affiliates of Riverstone to spin off PPL Energy Supply and immediately combine it with Riverstone's competitive power generation businesses to form a new, stand-alone, publicly traded company named Talen Energy. The transaction was subject to customary closing conditions, including receipt of regulatory approvals from the NRC, FERC, DOJ and PUC, all of which were received by mid-April 2015. On April 29, 2015, PPL's Board of Directors declared the June 1, 2015 distribution to PPL's shareowners of record on May 20, 2015 of a newly formed entity, Holdco, which at closing owned all of the membership interests of PPL Energy Supply and all of the common stock of Talen Energy.
Number of shares of Talen common stock for one share of PPL common stock | shares	0.1249
Initial percent ownership in new company, Talen Energy, by PPL shareowners	65.00%
Initial percent ownership in new company, Talen Energy, by Riverstone Holdings, LLC	35.00%
Number of approaches | Integer				3
Net assets distributed	$ 3,200
Number of market approaches | Integer				2
Review period used in determining the control premium (in years)				5 years
Minimum transaction value reviewed in determining the control premium				$ 1,000
Carrying value of the Supply segment	4,100
Gain (loss) on interest rate swaps recognized in discontinued operations on the statement of income	(72)
Gain (loss), after-tax, on interest rate swaps recognized in discontinued operations on the statement of income	(42)
Adjustment for loss on spinoff	879
Continuing Involvement (Details) [Abstract]
Amount for services billed to spinoff							$ 1	35	25
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Results of Discontinued Operations (Details) [Abstract]
Operating revenues									1,427
Operating expenses									1,328
Other Income (Expense) - net									(21)
Interest expense									150
Income tax expense (benefit)									(30)
Gain (loss) on disposal group									(879)
Loss from Discontinued Operations (net of income taxes)									(921)
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Net assets distributed	3,200
PPL Energy Supply Spinoff [Member] | Talen Energy Market Value [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Weighting				50.00%
Net assets distributed	1,400
Midpoint of premiums received in market sales transactions reviewed				25.00%
Control Premium				25.00%
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Net assets distributed	1,400
PPL Energy Supply Spinoff [Member] | Talen Energy Market Value [Member] | Minimum [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Control Premium				5.00%
PPL Energy Supply Spinoff [Member] | Talen Energy Market Value [Member] | Maximum [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Control Premium				42.00%
PPL Energy Supply Spinoff [Member] | Income Discounted Cash Flow [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Weighting				30.00%
Net assets distributed	1,100
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Net assets distributed	1,100
PPL Energy Supply Spinoff [Member] | Alternative Market Comparable Company [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Weighting				20.00%
Net assets distributed	$ 700
Midpoint of premiums received in market sales transactions reviewed	25.00%
Control Premium	25.00%
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Net assets distributed	$ 700
PPL Energy Supply Spinoff [Member] | Alternative Market Comparable Company [Member] | Minimum [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Control Premium	5.00%
PPL Energy Supply Spinoff [Member] | Alternative Market Comparable Company [Member] | Maximum [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Control Premium	42.00%
Spinoff [Member] | PPL Energy Supply Spinoff [Member]
Divestitures - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Separation benefits								10
Third-party costs								45
Spinoff [Member] | PPL Energy Supply Spinoff [Member] | Other Operation Maintenance [Member]
Divestitures - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Separation benefits								8
Consulting and other costs								13
Spinoff [Member] | PPL Energy Supply Spinoff [Member] | Discontinued Operations [Member]
Divestitures - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Separation benefits								2
Employee-related costs recognized	$ 24
Bank advisory, legal and accounting fees								32
PPL Electric [Member] | Northeast Pocono Reliability Project [Member]
Development Projects [Abstract]
Total length (in miles) of the expansion project | mi							58
Capacity (in kilovolts) of a transmission line | kV							230
Number of new substations included in request | Integer							3
Adder to the return on equity incentive denied in ratemaking request (in basis points) | Integer							100
Project costs capitalized							$ 350
PPL Electric [Member] | PPL Energy Supply Spinoff [Member] | Talen Energy Marketing [Member]
Continuing Involvement (Details) [Abstract]
Energy purchases						$ 27	$ 0	106
LGE [Member]
Development Projects [Abstract]
Generating units retired at the Cane Run plant | coal-fired_unit				2	1
Costs associated with the retirement of generating units			$ 11
KU [Member]
Development Projects [Abstract]
Generating Units Retired Plant Anticipated | coal-fired_unit							2
Generating Units Retired Megawatts Anticipated | Integer							272
Generating Units Retired Plant Two | coal-fired_unit			2
Costs associated with the retirement of generating units			$ 6
LGE and KU [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Completed Megawatt Expansion Of Capacity | MW		10
Actual Capital Cost Of Expansion Project		$ 25
PPL Electric Utilities Corp [Member]
Continuing Involvement (Details) [Abstract]
Energy purchases							$ 507	535	657
PPL Electric Utilities Corp [Member] | Northeast Pocono Reliability Project [Member]
Development Projects [Abstract]
Total length (in miles) of the expansion project | mi							58
Capacity (in kilovolts) of a transmission line | kV							230
Number of new substations included in request | Integer							3
Adder to the return on equity incentive denied in ratemaking request (in basis points) | Integer							100
Project costs capitalized							$ 350
PPL Electric Utilities Corp [Member] | PPL Energy Supply Spinoff [Member] | Talen Energy Marketing [Member]
Continuing Involvement (Details) [Abstract]
Energy purchases						$ 27	106
LG And E And KU Energy LLC [Member]
Continuing Involvement (Details) [Abstract]
Energy purchases							$ 178	171	184
LG And E And KU Energy LLC [Member] | LGE [Member]
Development Projects [Abstract]
Generating units retired at the Cane Run plant | coal-fired_unit				2	1
Costs associated with the retirement of generating units			$ 11
LG And E And KU Energy LLC [Member] | KU [Member]
Development Projects [Abstract]
Generating Units Retired Plant Anticipated | coal-fired_unit							2
Generating Units Retired Megawatts Anticipated | Integer							272
Generating Units Retired Plant Two | coal-fired_unit			2
Costs associated with the retirement of generating units			$ 6
LG And E And KU Energy LLC [Member] | LGE and KU [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Completed Megawatt Expansion Of Capacity | MW		10
Actual Capital Cost Of Expansion Project		$ 25
Louisville Gas And Electric Co [Member]
Continuing Involvement (Details) [Abstract]
Energy purchases							$ 160	153	166
Development Projects [Abstract]
Generating units retired at the Cane Run plant | coal-fired_unit				2	1
Costs associated with the retirement of generating units			$ 11
Louisville Gas And Electric Co [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Completed Megawatt Expansion Of Capacity | MW		10
Actual Capital Cost Of Expansion Project		$ 25
Kentucky Utilities Co [Member]
Continuing Involvement (Details) [Abstract]
Energy purchases							$ 18	$ 18	$ 18
Development Projects [Abstract]
Generating Units Retired Plant Anticipated | coal-fired_unit							2
Generating Units Retired Megawatts Anticipated | Integer							272
Generating Units Retired Plant Two | coal-fired_unit			2
Costs associated with the retirement of generating units			$ 6
Kentucky Utilities Co [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Completed Megawatt Expansion Of Capacity | MW		10
Actual Capital Cost Of Expansion Project		$ 25

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Rent - Operating Leases (Details) [Abstract]
Operating leases, rent expense	$ 45	$ 50	$ 49
Operating leases, future minimum rental payments due (Details) [Abstract]
2,018	32
2,019	19
2,020	13
2,021	10
2,022	8
Thereafter	22
Total	104
LG And E And KU Energy LLC [Member]
Rent - Operating Leases (Details) [Abstract]
Operating leases, rent expense	26	26	24
Operating leases, future minimum rental payments due (Details) [Abstract]
2,018	26
2,019	16
2,020	11
2,021	8
2,022	6
Thereafter	15
Total	82
Louisville Gas And Electric Co [Member]
Rent - Operating Leases (Details) [Abstract]
Operating leases, rent expense	15	15	12
Operating leases, future minimum rental payments due (Details) [Abstract]
2,018	15
2,019	8
2,020	5
2,021	3
2,022	2
Thereafter	6
Total	39
Kentucky Utilities Co [Member]
Rent - Operating Leases (Details) [Abstract]
Operating leases, rent expense	11	$ 11	$ 11
Operating leases, future minimum rental payments due (Details) [Abstract]
2,018	10
2,019	8
2,020	6
2,021	5
2,022	4
Thereafter	8
Total	$ 41

Stock-Based Compensation (Detai

Stock-Based Compensation (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Integer$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / shares
All Plans [Member] | Restricted Shares And Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested, beginning of period (in shares)	1,337,025
Granted (in shares)	538,441
Vested (in shares)	(567,001)
Forfeited (in shares)	(16,816)
Nonvested, end of period (in shares)	1,291,649	1,337,025
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares	$ 31.57
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	35.30	$ 33.84	$ 34.50
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares	29.28
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	34.28
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 34.10	$ 31.57
Total fair value of units vested during the period | $	$ 20,000,000	$ 30,000,000	$ 28,000,000
Fair value assumptions and methodology [Abstract]
Award vesting period (in years)	3 years	3 years	3 years
All Plans [Member] | Restricted Shares And Units [Member] | PPL Energy Supply Spinoff [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Vested (in shares)	(252,850)
All Plans [Member] | Total Shareowner Return Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested, beginning of period (in shares)	1,070,536
Granted (in shares)	293,642
Vested (in shares)	(243,983)
Forfeited (in shares)	(141,964)
Nonvested, end of period (in shares)	978,231	1,070,536
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares	$ 34.65
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	38.38	$ 35.74	$ 36.76
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares	32.42
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	32.27
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 36.67	$ 34.65
Total fair value of units vested during the period | $	$ 8,000,000	$ 12,000,000	$ 6,000,000
Period over which performance units fair value is recognized (in years)	3 years	3 years	3 years
Maximum payout percentage of target award	200.00%	200.00%	200.00%
Fair value assumptions and methodology [Abstract]
Expected option life (in years)	3 years	3 years	3 years
Expected stock volatility	17.40%	19.60%	15.90%
All Plans [Member] | Total Shareowner Return Performance Units [Member] | PPL Energy Supply Spinoff [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Vested (in shares)	(41,405)
All Plans [Member] | Total Shareowner Return Performance Units [Member] | Retirement Eligible [Member]
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Period over which performance units fair value is recognized (in years)	1 year	1 year	1 year
All Plans [Member] | Total Shareowner Return Performance Units [Member] | Not Retirement Eligible [Member]
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Period over which performance units fair value is recognized (in years)	3 years	3 years	3 years
Minimum period after which employee stock options become exercisable (in years)	1 year	1 year	1 year
All Plans [Member] | Return On Equity Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Granted (in shares)	97,925
Forfeited (in shares)	(997)
Nonvested, end of period (in shares)	96,928
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	$ 34.42
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	34.41
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 34.42
Period over which performance units fair value is recognized (in years)	3 years
Maximum payout percentage of target award	200.00%
All Plans [Member] | Stock Options [Member]
Stock option activity [Roll Forward]
Outstanding at beginning of period (in shares)	4,481,160
Exercised (in shares)	(718,977)
Outstanding at end of period (in shares)	3,762,183	4,481,160
Stock options - additional disclosures [Abstract]
Period after which, employee stock options expire (in years)	10 years
Weighted-average exercise price per share at beginning of period (in dollars per share) | $ / shares	$ 28.98
Weighted average exercise price per share, exercised (in dollars per share) | $ / shares	26.67
Weighted average exercise price per share at end of period (in dollars per share) | $ / shares	$ 29.42	$ 28.98
Weighted average remaining contractual term (in years)	3 years 6 months
Aggregate total intrinsic value | $	$ 14,000,000
Cash received from exercise of stock options | $	19,000,000	$ 52,000,000	$ 97,000,000
Total intrinsic value of stock options exercised | $	8,000,000	18,000,000	21,000,000
All Plans [Member] | All Awards [Member]
Aggregate disclosures [Abstract]
Compensation expense | $	32,000,000	27,000,000	33,000,000
Income tax benefit | $	13,000,000	$ 12,000,000	$ 14,000,000
Unrecognized compensation expense | $	$ 10,000,000
Weighted-average period for recognition | Integer	1.7
Stock Incentive Plan [Member]
Stock-Based Compensation [Line Items]
Maximum number of shares approved for awards under the plan (in shares)	15,000,000
Annual grant limit options (in shares)	2,000,000
Annual grant limit for individual participants - performance based awards (in shares)	750,000
Annual grant limit for individual participants - performance based awards | $	$ 15,000,000
Incentive Compensation Plan For Key Employees [Member]
Stock-Based Compensation [Line Items]
Maximum number of shares approved for awards under the plan (in shares)	14,199,796
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year	2.00%
Annual grant limit options (in shares)	3,000,000
PPL Electric Utilities Corp [Member] | All Plans [Member] | Restricted Shares And Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested, beginning of period (in shares)	204,570
Transfer between registrants	(5,250)
Granted (in shares)	79,321
Vested (in shares)	(91,117)
Forfeited (in shares)	(3,108)
Nonvested, end of period (in shares)	184,416	204,570
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares	$ 31.27
Weighted-average grant date fair value per share, transfer between registrants (in dollars per share) | $ / shares	32.05
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	35.45	$ 34.32	$ 34.41
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares	28.83
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	34.68
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 34.20	$ 31.27
Total fair value of units vested during the period | $	$ 3,000,000	$ 3,000,000	$ 4,000,000
Fair value assumptions and methodology [Abstract]
Award vesting period (in years)	3 years	3 years	3 years
PPL Electric Utilities Corp [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested, beginning of period (in shares)	76,726
Granted (in shares)	26,086
Vested (in shares)	(14,713)
Forfeited (in shares)	(12,586)
Nonvested, end of period (in shares)	75,513	76,726
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares	$ 34.68
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	38.37	$ 35.68	$ 37.93
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares	32.14
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	35.45
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 37	$ 34.68
Period over which performance units fair value is recognized (in years)	3 years	3 years	3 years
Maximum payout percentage of target award	200.00%	200.00%	200.00%
PPL Electric Utilities Corp [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Retirement Eligible [Member]
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Period over which performance units fair value is recognized (in years)	1 year	1 year	1 year
PPL Electric Utilities Corp [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Not Retirement Eligible [Member]
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Period over which performance units fair value is recognized (in years)	3 years	3 years	3 years
Minimum period after which employee stock options become exercisable (in years)	1 year	1 year	1 year
PPL Electric Utilities Corp [Member] | All Plans [Member] | Return On Equity Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Granted (in shares)	8,696
Nonvested, end of period (in shares)	8,696
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	$ 34.41
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 34.41
Period over which performance units fair value is recognized (in years)	3 years
Maximum payout percentage of target award	200.00%
PPL Electric Utilities Corp [Member] | All Plans [Member] | Performance Units [Member]
Fair value assumptions and methodology [Abstract]
Expected option life (in years)	3 years	3 years	3 years
Expected stock volatility	17.40%	19.60%	15.90%
PPL Electric Utilities Corp [Member] | All Plans [Member] | Stock Options [Member]
Stock option activity [Roll Forward]
Outstanding at beginning of period (in shares)	240,939
Exercised (in shares)	(42,659)
Outstanding at end of period (in shares)	198,280	240,939
Stock options - additional disclosures [Abstract]
Period after which, employee stock options expire (in years)	10 years
Weighted-average exercise price per share at beginning of period (in dollars per share) | $ / shares	$ 27.48
Weighted average exercise price per share, exercised (in dollars per share) | $ / shares	26.99
Weighted average exercise price per share at end of period (in dollars per share) | $ / shares	$ 27.58	$ 27.48
Weighted average remaining contractual term (in years)	3 years 9 months
Aggregate total intrinsic value, options exercisable at end of period | $	$ 1,000,000
PPL Electric Utilities Corp [Member] | All Plans [Member] | All Awards [Member]
Aggregate disclosures [Abstract]
Compensation expense | $	18,000,000	$ 16,000,000	$ 14,000,000
Income tax benefit | $	8,000,000	$ 7,000,000	$ 6,000,000
Unrecognized compensation expense | $	$ 2,000,000
Weighted-average period for recognition | Integer	1.7
PPL Electric Utilities Corp [Member] | Stock Incentive Plan [Member]
Stock-Based Compensation [Line Items]
Maximum number of shares approved for awards under the plan (in shares)	15,000,000
Annual grant limit options (in shares)	2,000,000
Annual grant limit for individual participants - performance based awards (in shares)	750,000
Annual grant limit for individual participants - performance based awards | $	$ 15,000,000
PPL Electric Utilities Corp [Member] | Incentive Compensation Plan For Key Employees [Member]
Stock-Based Compensation [Line Items]
Maximum number of shares approved for awards under the plan (in shares)	14,199,796
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year	2.00%
Annual grant limit options (in shares)	3,000,000
LG And E And KU Energy LLC [Member] | All Plans [Member] | Restricted Shares And Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested, beginning of period (in shares)	243,281
Transfer between registrants	25,337
Granted (in shares)	97,775
Vested (in shares)	(125,612)
Forfeited (in shares)	(9,224)
Nonvested, end of period (in shares)	231,557	243,281
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares	$ 31.53
Weighted-average grant date fair value per share, transfer between registrants (in dollars per share) | $ / shares	31.61
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	35.25	$ 33.73	$ 34.89
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares	29.68
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	34.04
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 34.01	$ 31.53
Total fair value of units vested during the period | $	$ 4,000,000	$ 5,000,000	$ 4,000,000
Fair value assumptions and methodology [Abstract]
Award vesting period (in years)	3 years	3 years	3 years
LG And E And KU Energy LLC [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested, beginning of period (in shares)	191,601
Transfer between registrants	8,307
Granted (in shares)	64,555
Vested (in shares)	(48,980)
Forfeited (in shares)	(35,194)
Nonvested, end of period (in shares)	180,289	191,601
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, nonvested, beginning of period (in dollars per share) | $ / shares	$ 34.34
Weighted-average grant date fair value per share, transfer between registrants (in dollars per share) | $ / shares	35.96
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	38.24	$ 35.28	$ 37.10
Weighted-average grant date fair value per share, vested (in dollars per share) | $ / shares	32.09
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	35.25
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 36.69	$ 34.34
Period over which performance units fair value is recognized (in years)	3 years	3 years	3 years
Maximum payout percentage of target award	200.00%	200.00%	200.00%
LG And E And KU Energy LLC [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Retirement Eligible [Member]
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Period over which performance units fair value is recognized (in years)	1 year	1 year	1 year
LG And E And KU Energy LLC [Member] | All Plans [Member] | Total Shareowner Return Performance Units [Member] | Not Retirement Eligible [Member]
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Period over which performance units fair value is recognized (in years)	3 years	3 years	3 years
Minimum period after which employee stock options become exercisable (in years)	1 year	1 year	1 year
LG And E And KU Energy LLC [Member] | All Plans [Member] | Return On Equity Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Granted (in shares)	21,536
Forfeited (in shares)	(997)
Nonvested, end of period (in shares)	20,539
Awards, Equity Instruments Other than Options, additional disclosures (Details) [Abstract]
Weighted-average grant date fair value per share, granted (in dollars per share) | $ / shares	$ 34.29
Weighted-average grant date fair value per share, forfeited (in dollars per share) | $ / shares	34.41
Weighted-average grant date fair value per share, nonvested - end of period (in dollars per share) | $ / shares	$ 34.29
Period over which performance units fair value is recognized (in years)	3 years
Maximum payout percentage of target award	200.00%
LG And E And KU Energy LLC [Member] | All Plans [Member] | Performance Units [Member]
Fair value assumptions and methodology [Abstract]
Expected option life (in years)	3 years	3 years	3 years
Expected stock volatility	17.40%	19.60%	15.90%
LG And E And KU Energy LLC [Member] | All Plans [Member] | Stock Options [Member]
Stock option activity [Roll Forward]
Outstanding at beginning of period (in shares)	61,896
Exercised (in shares)	(28,164)
Outstanding at end of period (in shares)	33,732	61,896
Stock options - additional disclosures [Abstract]
Period after which, employee stock options expire (in years)	10 years
Weighted-average exercise price per share at beginning of period (in dollars per share) | $ / shares	$ 25.81
Weighted average exercise price per share, exercised (in dollars per share) | $ / shares	26.59
Weighted average exercise price per share at end of period (in dollars per share) | $ / shares	$ 25.15	$ 25.81
Weighted average remaining contractual term (in years)	4 years 1 month
Aggregate total intrinsic value, options exercisable at end of period | $	$ 0
LG And E And KU Energy LLC [Member] | All Plans [Member] | All Awards [Member]
Aggregate disclosures [Abstract]
Compensation expense | $	8,000,000	$ 7,000,000	$ 8,000,000
Income tax benefit | $	3,000,000	$ 3,000,000	$ 3,000,000
Unrecognized compensation expense | $	$ 1,000,000
Weighted-average period for recognition | Integer	1.6
LG And E And KU Energy LLC [Member] | Stock Incentive Plan [Member]
Stock-Based Compensation [Line Items]
Maximum number of shares approved for awards under the plan (in shares)	15,000,000
Annual grant limit options (in shares)	2,000,000
Annual grant limit for individual participants - performance based awards (in shares)	750,000
Annual grant limit for individual participants - performance based awards | $	$ 15,000,000
LG And E And KU Energy LLC [Member] | Incentive Compensation Plan For Key Employees [Member]
Stock-Based Compensation [Line Items]
Maximum number of shares approved for awards under the plan (in shares)	14,199,796
Annual grant limit total as % of PPL outstanding PPL common stock on first day of each calendar year	2.00%
Annual grant limit options (in shares)	3,000,000

Retirement and Postemployment78

Retirement and Postemployment Benefits (Net Period Defined Benefit Costs (Credits) and Other Changes in Plan Assets and Benefit Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member] | U.S. [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	$ 65	$ 66	$ 96
Interest cost	168	174	194
Expected return on plan assets	(231)	(228)	(258)
Amortization of:
Prior service cost (credit)	10	8	7
Actuarial (gain) loss	69	50	84
Net periodic defined benefit costs (credits) prior to settlements and termination benefits	81	70	123
Settlements	1	3	0
Termination benefits	1	0	0
Net periodic defined benefit costs (credits)	83	73	123
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Divestiture	0	0	(353)
Settlement	(1)	(3)	0
Net (gain) loss	27	253	63
Prior service costs (credit)	(1)	15	18
Amortization of: [Abstract]
Prior service (cost) credit	(10)	(8)	(7)
Actuarial gain (loss)	(69)	(50)	(85)
Total recognized in OCI and regulatory assets/liabilities	(54)	207	(364)
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	29	280	(241)
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	(53)	236	(269)
Regulatory assets/liabilities	(1)	(29)	(95)
Total recognized in OCI and regulatory assets/liabilities	(54)	207	(364)
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)	10
Actuarial (gain) loss	86
Total	96
Amortization from Balance Sheet: [Abstract]
AOCI	28
Regulatory assets/liabilities	68
Total	96
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	59	53	71
Pension Plan [Member] | U.K. [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	76	69	79
Interest cost	178	235	314
Expected return on plan assets	(514)	(504)	(523)
Amortization of:
Prior service cost (credit)	0	0	0
Actuarial (gain) loss	144	138	158
Net periodic defined benefit costs (credits) prior to settlements and termination benefits	(116)	(62)	28
Settlements	0	0	0
Termination benefits	0	0	0
Net periodic defined benefit costs (credits)	(116)	(62)	28
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Divestiture	0	0	0
Settlement	0	0	0
Net (gain) loss	346	7	508
Prior service costs (credit)	0	0	0
Amortization of: [Abstract]
Prior service (cost) credit	0	0	0
Actuarial gain (loss)	(144)	(138)	(158)
Total recognized in OCI and regulatory assets/liabilities	202	(131)	350
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	86	(193)	378
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
Total recognized in OCI and regulatory assets/liabilities	202	(131)	350
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)	0
Actuarial (gain) loss	152
Total	152
Amortization from Balance Sheet: [Abstract]
AOCI	152
Regulatory assets/liabilities	0
Total	152
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	(151)	(95)	(21)
Other Postretirement Benefits Plan [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	7	7	11
Interest cost	23	26	26
Expected return on plan assets	(22)	(22)	(26)
Amortization of:
Prior service cost (credit)	(1)	0	1
Actuarial (gain) loss	1	1	0
Net periodic defined benefit costs (credits) prior to settlements and termination benefits	8	12	12
Settlements	0	0	0
Termination benefits	0	0	0
Net periodic defined benefit costs (credits)	8	12	12
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Divestiture	0	0	(6)
Settlement	0	0	0
Net (gain) loss	(28)	9	(9)
Prior service costs (credit)	8	0	0
Amortization of: [Abstract]
Prior service (cost) credit	1	(1)	(1)
Actuarial gain (loss)	(1)	(1)	0
Total recognized in OCI and regulatory assets/liabilities	(20)	7	(16)
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	(12)	19	(4)
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	(25)	7	12
Regulatory assets/liabilities	5	0	(28)
Total recognized in OCI and regulatory assets/liabilities	(20)	7	(16)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 5	7	8
PPL Electric Utilities Corp [Member]
Amortization of:
Amortization period for the deferred recovery of a regulatory asset	5 years
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Amortization period for the deferred recovery of a regulatory asset	5 years
PPL Electric Utilities Corp [Member] | Pension Plan [Member] | U.S. [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 12	10	15
PPL Electric Utilities Corp [Member] | Other Postretirement Benefits Plan [Member]
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	0	1	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member]
Amortization of:
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	11	6	9
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	(11)	(6)	(9)
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	24	23	26
Interest cost	68	71	68
Expected return on plan assets	(92)	(91)	(88)
Amortization of:
Prior service cost (credit)	8	8	7
Actuarial (gain) loss	31	21	37
Net periodic defined benefit costs (credits)	$ 39	$ 32	$ 50
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss	$ 30	$ 119	$ 20
Prior service costs (credit)	7	0	19
Amortization of: [Abstract]
Prior service (cost) credit	(8)	(8)	(7)
Actuarial gain (loss)	(32)	(21)	(37)
Total recognized in OCI and regulatory assets/liabilities	(3)	90	(5)
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	36	122	45
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	33	42	4
Regulatory assets/liabilities	(36)	48	(9)
Total recognized in OCI and regulatory assets/liabilities	(3)	90	(5)
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)	9
Actuarial (gain) loss	39
Total	48
Amortization from Balance Sheet: [Abstract]
AOCI	11
Regulatory assets/liabilities	37
Total	48
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 28	$ 24	$ 37
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Qualified Plan [Member]
Amortization of:
Settlements	$ 5
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits Plan [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	4	$ 5	$ 5
Interest cost	9	9	9
Expected return on plan assets	(7)	(6)	(6)
Amortization of:
Prior service cost (credit)	1	3	3
Actuarial (gain) loss	0	(1)	0
Net periodic defined benefit costs (credits)	$ 7	$ 10	$ 11
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss	$ (14)	$ 6	$ (15)
Prior service costs (credit)	8	0	0
Amortization of: [Abstract]
Prior service (cost) credit	(1)	(3)	(3)
Actuarial gain (loss)	0	1	0
Total recognized in OCI and regulatory assets/liabilities	(7)	4	(18)
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	0	14	(7)
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	(2)	2	(2)
Regulatory assets/liabilities	(5)	2	(16)
Total recognized in OCI and regulatory assets/liabilities	(7)	4	(18)
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)	1
Actuarial (gain) loss	0
Total	1
Amortization from Balance Sheet: [Abstract]
AOCI	0
Regulatory assets/liabilities	1
Total	1
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 5	$ 6	$ 8
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
LG And E And KU Energy LLC [Member] | KU [Member] | Other Postretirement Benefits Plan [Member]
Amortization of:
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ (2)	$ (2)	$ (1)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	2	2	1
LG And E And KU Energy LLC [Member] | LGE [Member] | Other Postretirement Benefits Plan [Member]
Amortization of:
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	(4)	(3)	(4)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	4	3	4
Louisville Gas And Electric Co [Member] | Pension Plan [Member]
Amortization of:
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	7	5	3
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	(7)	(5)	(3)
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	1	1	1
Interest cost	13	15	14
Expected return on plan assets	(22)	(21)	(20)
Amortization of:
Prior service cost (credit)	5	4	3
Actuarial (gain) loss	9	7	11
Net periodic defined benefit costs (credits)	$ 6	$ 6	$ 9
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ (4)	$ (3)	$ (4)
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Net (gain) loss	(9)	22	8
Prior service costs (credit)	7	0	10
Amortization of: [Abstract]
Prior service (cost) credit	(5)	(4)	(3)
Actuarial gain (loss)	(9)	(7)	(11)
Total recognized in OCI and regulatory assets/liabilities	(16)	11	4
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	(10)	17	13
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
Total recognized in OCI and regulatory assets/liabilities	(16)	11	4
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Prior service cost (credit)	5
Actuarial (gain) loss	9
Total	14
Amortization from Balance Sheet: [Abstract]
Total	14
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 8	$ 8	$ 12
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 4	$ 3	$ 4
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Qualified Plan [Member]
Amortization of:
Settlements	5
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	$ 5	$ 4	$ 5
Louisville Gas And Electric Co [Member] | Other Postretirement Benefits Plan [Member]
Amortization of:
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ (4)	$ (3)	$ (4)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 3	$ 3	$ 4
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 4	$ 3	$ 4
Louisville Gas And Electric Co [Member] | Other Postretirement Benefits Plan [Member] | LKE [Member]
Net Periodic Defined Benefit Costs Allocated to Subsidiary by Sponsor (Numeric) [Abstract]
Costs allocated to subsidiary by plan sponsors	$ 3	$ 3	$ 4
Kentucky Utilities Co [Member] | Pension Plan [Member] | U.S. [Member]
Amortization of:
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ (2)	$ (2)	$ (1)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 4	$ 5	$ 9
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 2	$ 2	$ 1
Kentucky Utilities Co [Member] | Other Postretirement Benefits Plan [Member]
Amortization of:
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ (2)	$ (2)	$ (1)
Net Periodic Defined Benefit Costs (Credits) Charged to Operating Expense or Regulatory Assets, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs (credits) charged to operating expense or regulatory assets, excluding amounts charged to construction and other non-expense accounts	$ 1	$ 2	$ 2
Amortization period for the deferred recovery of a regulatory asset	15 years	15 years	15 years
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 2	$ 2	$ 1

Retirement and Postemployment79

Retirement and Postemployment Benefits (Weighted-Average Assumptions, Cost Trend Rates and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	$ 284	$ 9
Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	3.70%	4.21%
Benefit obligations valuation rate of compensation increase	3.78%	3.95%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	4.21%	4.59%	4.25%
Net periodic benefit costs discount rate - interest cost	4.21%	4.59%	4.25%
Net periodic benefit costs rate of compensation increase	3.95%	3.93%	3.91%
Net periodic benefit costs expected return on plan assets	7.00%	7.00%	7.00%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.60%	7.00%	6.80%
Health care cost trend rate assumed for next year, cost	7.00%	6.80%	7.20%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), obligations	5.00%	5.00%	5.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), cost	5.00%	5.00%	5.00%
Year that the rate reaches the ultimate trend rate, obligations	2,022	2,022	2,020
Year that the rate reaches the ultimate trend rate, cost	2,022	2,020	2,020
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 4,079	$ 3,863
Service cost	65	66	$ 96
Interest cost	168	174	194
Participant contributions	0	0
Plan Amendments	(1)	14
Actuarial (gain) loss	233	214
Settlements	(6)	(9)
Termination benefits	1	0
Gross benefits paid	(251)	(243)
Federal subsidy	0	0
Currency conversion	0	0
Benefit Obligation, end of period	4,288	4,079	3,863
Change in Plan Assets [Roll Forward]
Balance at beginning of period	3,243	3,227
Actual return on plan assets	437	189
Employer contributions	65	79
Participant contributions	0	0
Settlements	(6)	(9)
Gross benefits paid	(251)	(243)
Currency conversion	0	0
Balance at end of period	3,488	3,243	$ 3,227
Funded Status, end of period	(800)	(836)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	0	0
Current liability	(13)	(17)
Noncurrent liability	(787)	(819)
Net amount recognized, end of period	(800)	(836)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	49	59
Net actuarial (gain) loss	1,134	1,178
Total	1,183	1,237
Total accumulated benefit obligation for defined benefit pension plans	4,000	3,807
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	374	357
Regulatory assets/liabilities	809	880
Total	1,183	1,237
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	4,288	4,079
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	3,488	3,243
Accumulated benefit obligation	4,000	3,807
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 3,488	$ 3,243
Pension Plan [Member] | U.K. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	2.65%	2.87%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	2.99%	3.90%	3.85%
Net periodic benefit costs discount rate - interest cost	2.41%	3.14%	3.85%
Net periodic benefit costs rate of compensation increase	3.50%	4.00%	4.00%
Net periodic benefit costs expected return on plan assets	7.22%	7.20%	7.19%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 7,383	$ 8,404
Service cost	76	69	$ 79
Interest cost	178	235	314
Participant contributions	13	14
Plan Amendments	0	0
Actuarial (gain) loss	293	484
Settlements	(1)	0
Termination benefits	0	0
Gross benefits paid	(345)	(357)
Federal subsidy	0	0
Currency conversion	622	(1,466)
Benefit Obligation, end of period	8,219	7,383	8,404
Change in Plan Assets [Roll Forward]
Balance at beginning of period	7,211	7,625
Actual return on plan assets	480	979
Employer contributions	486	330
Participant contributions	13	14
Settlements	(1)	0
Gross benefits paid	(345)	(357)
Currency conversion	646	(1,380)
Balance at end of period	8,490	7,211	$ 7,625
Funded Status, end of period	271	(172)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	284	10
Current liability	0	0
Noncurrent liability	(13)	(182)
Net amount recognized, end of period	271	(172)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	0	0
Net actuarial (gain) loss	2,755	2,553
Total	2,755	2,553
Total accumulated benefit obligation for defined benefit pension plans	7,542	6,780
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	2,755	2,553
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	3,083	3,403
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	3,070	3,221
Accumulated benefit obligation	10	657
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 0	$ 643
Other Postretirement Benefits Plan [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	3.64%	4.11%
Benefit obligations valuation rate of compensation increase	3.75%	3.92%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate - service cost	4.11%	4.48%	4.09%
Net periodic benefit costs discount rate - interest cost	4.11%	4.48%	4.09%
Net periodic benefit costs rate of compensation increase	3.92%	3.91%	3.86%
Net periodic benefit costs expected return on plan assets	6.21%	6.11%	6.06%
Effect of One Percentage Point Change in Assumed Health Care Costs Trend Rate (Details) [Abstract]
Effect on accumulated postretirement benefit obligation of a one percentage point increase	$ 4
Effect on accumulated postretirement benefit obligation of a one percentage point decrease	(4)
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	591	$ 596
Service cost	7	7	$ 11
Interest cost	23	26	26
Participant contributions	14	14
Plan Amendments	8	0
Actuarial (gain) loss	4	11
Settlements	0	0
Termination benefits	0	0
Gross benefits paid	(59)	(64)
Federal subsidy	1	1
Currency conversion	0	0
Benefit Obligation, end of period	589	591	596
Change in Plan Assets [Roll Forward]
Balance at beginning of period	378	379
Actual return on plan assets	54	25
Employer contributions	15	19
Participant contributions	13	14
Settlements	0	0
Gross benefits paid	(55)	(59)
Currency conversion	0	0
Balance at end of period	405	378	379
Funded Status, end of period	(184)	(213)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	2	2
Current liability	(3)	(3)
Noncurrent liability	(183)	(212)
Net amount recognized, end of period	(184)	(213)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	9	0
Net actuarial (gain) loss	16	45
Total	25	45
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	15	20
Regulatory assets/liabilities	10	25
Total	25	45
PPL Electric Utilities Corp [Member]
Change in Plan Assets [Roll Forward]
Non-cash contributions related to remeasurement and separation of benefit plans			56
PPL Electric Utilities Corp [Member] | Pension Plan [Member] | U.S. [Member] | PPL Services Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	246	281
Non-cash contributions related to remeasurement and separation of benefit plans			$ 56
PPL Electric Utilities Corp [Member] | Other Postretirement Benefits Plan [Member] | PPL Services Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	$ 62	$ 72
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	3.69%	4.19%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	4.19%	4.56%	4.25%
Net periodic benefit costs rate of compensation increase	3.50%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets	7.00%	7.00%	7.00%
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	6.60%	7.00%	6.80%
Health care cost trend rate assumed for next year, cost	7.00%	6.80%	7.20%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), obligations	5.00%	5.00%	5.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate), cost	5.00%	5.00%	5.00%
Year that the rate reaches the ultimate trend rate, obligations	2,022	2,022	2,020
Year that the rate reaches the ultimate trend rate, cost	2,022	2,020	2,020
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 1,669	$ 1,588
Service cost	24	23	$ 26
Interest cost	68	71	68
Participant contributions	0	0
Plan Amendments	6	0
Actuarial (gain) loss	113	96
Gross benefits paid	(109)	(109)
Benefit Obligation, end of period	1,771	1,669	1,588
Increase during the period resulting from a plan amendment		19
Defined Benefit Plan One Time Cash Payouts To Terminated Vested Employees	50	53
Change in Plan Assets [Roll Forward]
Balance at beginning of period	1,315	1,289
Actual return on plan assets	175	69
Employer contributions	21	66
Participant contributions	0	0
Gross benefits paid	(109)	(109)
Balance at end of period	1,402	1,315	$ 1,289
Funded Status, end of period	(369)	(354)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	0	0
Current liability	(4)	(4)
Noncurrent liability	(365)	(350)
Net amount recognized, end of period	(369)	(354)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	44	45
Net actuarial (gain) loss	434	436
Total	478	481
Total accumulated benefit obligation for defined benefit pension plans	1,616	1,531
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	144	111
Regulatory assets/liabilities	334	370
Total	478	481
Pension Plans Where the Projected or Accumulated Benefit Obligation Exceed the Fair Value of Plan Assets (Details) [Abstract]
Projected benefit obligations	1,771	1,669
Fair value of plan assets where the projected benefit obligations exceed the value of plan assets	1,402	1,315
Accumulated benefit obligation	1,616	1,531
Fair value of plan assets where the accumulated benefit obligations exceed the value of plan assets	$ 1,402	$ 1,315
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits Plan [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	3.65%	4.12%
Benefit obligations valuation rate of compensation increase	3.50%	3.50%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	4.12%	4.49%	4.06%
Net periodic benefit costs rate of compensation increase	3.50%	3.50%	3.50%
Net periodic benefit costs expected return on plan assets	6.82%	6.82%	6.82%
Effect of One Percentage Point Change in Assumed Health Care Costs Trend Rate (Details) [Abstract]
Effect on accumulated postretirement benefit obligation of a one percentage point increase	$ 3
Effect on accumulated postretirement benefit obligation of a one percentage point decrease	(3)
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	220	$ 216
Service cost	4	5	$ 5
Interest cost	9	9	9
Participant contributions	8	7
Plan Amendments	8	0
Actuarial (gain) loss	(7)	4
Gross benefits paid	(19)	(21)
Benefit Obligation, end of period	223	220	216
Change in Plan Assets [Roll Forward]
Balance at beginning of period	98	88
Actual return on plan assets	14	4
Employer contributions	15	20
Participant contributions	8	7
Gross benefits paid	(19)	(21)
Balance at end of period	116	98	$ 88
Funded Status, end of period	(107)	(122)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	2	2
Current liability	(3)	(3)
Noncurrent liability	(106)	(121)
Net amount recognized, end of period	(107)	(122)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	13	6
Net actuarial (gain) loss	(26)	(13)
Total	(13)	(7)
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	6	8
Regulatory assets/liabilities	(19)	(15)
Total	$ (13)	$ (7)
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member]
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	3.65%	4.13%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	4.13%	4.49%	4.20%
Net periodic benefit costs expected return on plan assets	7.00%	7.00%	7.00%
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	$ 329	$ 326
Service cost	1	1	$ 1
Interest cost	13	15	14
Plan Amendments	6	0
Actuarial (gain) loss	11	15
Gross benefits paid	(34)	(28)
Benefit Obligation, end of period	326	329	326
Increase during the period resulting from a plan amendment		10
Defined Benefit Plan One Time Cash Payouts To Terminated Vested Employees	19	14
Change in Plan Assets [Roll Forward]
Balance at beginning of period	318	297
Actual return on plan assets	41	14
Employer contributions	0	35
Gross benefits paid	(34)	(28)
Balance at end of period	325	318	$ 297
Funded Status, end of period	(1)	(11)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent liability	(1)	(11)
Net amount recognized, end of period	(1)	(11)
Amounts recognized in AOCI and regulatory assets/liabilities (pre-tax): [Abstract]
Prior service cost (credit)	27	25
Net actuarial (gain) loss	(92)	110
Total	119	135
Total accumulated benefit obligation for defined benefit pension plans	326	329
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	119	135
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	44	42
Louisville Gas And Electric Co [Member] | Other Postretirement Benefits Plan [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	74	76
Kentucky Utilities Co [Member] | Pension Plan [Member] | U.S. [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	36	62
Kentucky Utilities Co [Member] | Other Postretirement Benefits Plan [Member] | LKE Funded Status Allocation [Member]
Change in Plan Assets [Roll Forward]
Funded Status, end of period	$ 32	$ 40

Retirement and Postemployment80

Retirement and Postemployment Benefits (Plan Assets and Expected Cash Flows) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Pension Plan [Member] | U.S. [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	$ 3,488	$ 3,243	$ 3,227	$ 3,488	$ 3,243
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	3,488	3,243	3,227
Balance at end of period		3,488	3,243
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		$ 65	79
Amount to be contributed to plan in the next fiscal year				0
Expected amount of benefit payments in the next period for non-qualified plans				13
Estimated Future Benefit Payments (Details) [Abstract]
2,018				260
2,019				269
2,020				268
2,021				270
2,022				272
2023-2027				1,328
Pension Plan [Member] | U.S. [Member] | Subsequent Event [Member]
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions	145
Pension Plan [Member] | U.S. [Member] | Master Trust [Member]
Assumptions Used in Calculations (Numeric) [Abstract]
The limited lives of four partnership of private equity investments (in years)		10 years
The amount of potential liability that maybe required to be funded by the master trust during life of the partnership				$ 28
Number Of Days Notice Required To Redeem Shares		45 days
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				100.00%	100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,561	$ 3,381	3,381	$ 3,561	$ 3,381
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	3,561	3,381
Balance at end of period		3,561	3,381
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	716	714	714	716	714
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	716	714
Balance at end of period		716	714
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	931	909	909	931	909
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	931	909
Balance at end of period		931	909
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	37	40	42	37	40
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	37	40	42
Actual return on plan assets relating to assets still held at the reporting date		1	1
Purchases, sales and settlements		(4)	(3)
Balance at end of period		37	40
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				301	181
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				301	181
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				229	152
Measured at fair value using net asset value per share				364	272
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				229	152
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | International Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				538	551
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				611	546
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				186	381
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				186	381
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				883	850
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				870	837
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				13	13
Fair value at end of period	13	13	10	13	13
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	13	13	10
Actual return on plan assets relating to assets still held at the reporting date		0	0
Purchases, sales and settlements		0	3
Balance at end of period		13	13
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				10	8
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				10	8
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				109	102
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Private Equity Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				80	80
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Hedge Fund Of Funds Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				175	167
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				50	61
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				50	61
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				1	3
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				1	3
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				24	27
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				24	27
Fair value at end of period	24	27	32	24	27
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	24	27	32
Actual return on plan assets relating to assets still held at the reporting date		1	1
Purchases, sales and settlements		(4)	(6)
Balance at end of period		24	27
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	72	(15)	(15)	72	(15)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	72	(15)
Balance at end of period		72	(15)
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	(145)	(123)	(123)	(145)	(123)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	(145)	(123)
Balance at end of period		(145)	(123)
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,488	3,243	3,243	$ 3,488	$ 3,243
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	3,488	3,243
Balance at end of period		3,488	3,243
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				56.00%	52.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				55.00%
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				32.00%	30.00%
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				14.00%	12.00%
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				10.00%	10.00%
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				43.00%	46.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				43.00%
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				39.00%	43.00%
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Derivatives [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				4.00%	3.00%
Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Liquidity Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				1.00%	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				2.00%
Pension Plan [Member] | U.K. [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				100.00%	100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	8,490	7,211	7,625	$ 8,490	$ 7,211
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	8,490	7,211	7,625
Balance at end of period		8,490	7,211
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		$ 486	330
Amount to be contributed to plan in the next fiscal year				191
Recurrence of formal actuarial valuations (in years)		3 years
Percentage of deficit funding requirements permitted to recover in rates		78.00%
Estimated Future Benefit Payments (Details) [Abstract]
2,018				343
2,019				349
2,020				353
2,021				356
2,022				362
2023-2027				1,843
Pension Plan [Member] | U.K. [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	216	$ 42	42	216	42
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	216	42
Balance at end of period		216	42
Pension Plan [Member] | U.K. [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,140	2,942	2,942	3,140	2,942
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	3,140	2,942
Balance at end of period		3,140	2,942
Pension Plan [Member] | U.K. [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	0	0	0	$ 0	$ 0
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	0	0
Balance at end of period		0	0
Pension Plan [Member] | U.K. [Member] | Cash And Cash Equivalents [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				2.00%	1.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				0.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				$ 216	$ 42
Pension Plan [Member] | U.K. [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				216	42
Pension Plan [Member] | U.K. [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.K. [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				$ 0	$ 0
Pension Plan [Member] | U.K. [Member] | U.K. Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				2.00%	3.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				2.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 157	$ 210
Pension Plan [Member] | U.K. [Member] | European Companies Excluding U.K. Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				1.00%	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				1.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 98	$ 177
Pension Plan [Member] | U.K. [Member] | Asian Pacific Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				1.00%	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				1.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 60	$ 140
Pension Plan [Member] | U.K. [Member] | North American Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				1.00%	3.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				1.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 123	$ 227
Pension Plan [Member] | U.K. [Member] | Emerging Markets Companies Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				1.00%	3.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				1.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 62	$ 209
Pension Plan [Member] | U.K. [Member] | Global Equities Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				16.00%	6.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				10.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 1,335	$ 466
Pension Plan [Member] | U.K. [Member] | Global Tactical Asset Allocation Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				33.00%	33.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				41.00%
Pension Plan [Member] | U.K. [Member] | Other Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 2,807	$ 2,363
Pension Plan [Member] | U.K. [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				37.00%	41.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				38.00%
Pension Plan [Member] | U.K. [Member] | U.K. Corporate Bonds Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				$ 3	$ 2
Pension Plan [Member] | U.K. [Member] | U.K. Corporate Bonds Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.K. [Member] | U.K. Corporate Bonds Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				3	2
Pension Plan [Member] | U.K. [Member] | U.K. Corporate Bonds Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.K. [Member] | U.K. Gilts Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				3,137	2,940
Pension Plan [Member] | U.K. [Member] | U.K. Gilts Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Pension Plan [Member] | U.K. [Member] | U.K. Gilts Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				3,137	2,940
Pension Plan [Member] | U.K. [Member] | U.K. Gilts Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				$ 0	$ 0
Pension Plan [Member] | U.K. [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				6.00%	6.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				5.00%
Pension Plan [Member] | U.K. [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 492	$ 435
Other Postretirement Benefits Plan [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				100.00%	100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	405	378	379	$ 405	$ 378
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	405	378	379
Balance at end of period		405	378
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		$ 15	19
Amount to be contributed to plan in the next fiscal year				14
Estimated Future Benefit Payments (Details) [Abstract]
2,018				51
2,019				51
2,020				50
2,021				49
2,022				48
2023-2027				218
Expected Federal Subsidy (Details) [Abstract]
Federal subsidy 2018				1
Federal subsidy 2019				0
Federal subsidy 2020				1
Federal subsidy 2021				0
Federal subsidy 2022				0
Federal subsidy 2023-2027				$ 2
Other Postretirement Benefits Plan [Member] | Cash And Cash Equivalents [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				4.00%	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				5.00%
Other Postretirement Benefits Plan [Member] | Money Market Funds [Member]
Assumptions Used in Calculations (Numeric) [Abstract]
Number of months from date of purchase that investment must mature		13 months
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	10	$ 5	5	$ 10	$ 5
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	10	5
Balance at end of period		10	5
Other Postretirement Benefits Plan [Member] | Money Market Funds [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				10	5
Other Postretirement Benefits Plan [Member] | Money Market Funds [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Other Postretirement Benefits Plan [Member] | Money Market Funds [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				$ 0	$ 0
Other Postretirement Benefits Plan [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				47.00%	48.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				45.00%
Other Postretirement Benefits Plan [Member] | United States Large Cap Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 123	$ 123
Other Postretirement Benefits Plan [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				$ 96	$ 114
Other Postretirement Benefits Plan [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				49.00%	50.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				50.00%
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	30	0	0	$ 30	$ 0
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	30	0
Balance at end of period		30	0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				30	0
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Other Postretirement Benefits Plan [Member] | Municipalities Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	12
Other Postretirement Benefits Plan [Member] | Municipalities Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Other Postretirement Benefits Plan [Member] | Municipalities Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	12
Other Postretirement Benefits Plan [Member] | Municipalities Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Other Postretirement Benefits Plan [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	1	1	1	1	1
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	1	1
Balance at end of period		1	1
Other Postretirement Benefits Plan [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	145	123	123	145	123
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	145	123
Balance at end of period		145	123
Other Postretirement Benefits Plan [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	259	254	254	259	254
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	259	254
Balance at end of period		259	254
Other Postretirement Benefits Plan [Member] | Total Trust Assets Not Including 401 H Assets [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	10	5	5	10	5
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	10	5
Balance at end of period		10	5
Other Postretirement Benefits Plan [Member] | Total Trust Assets Not Including 401 H Assets [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	30	12	12	30	12
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	30	12
Balance at end of period		30	12
Other Postretirement Benefits Plan [Member] | Total Trust Assets Not Including 401 H Assets [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	0	0	0	0	0
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	0	0
Balance at end of period		$ 0	$ 0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | Master Trust [Member]
Information About Plan Assets (Numeric) [Abstract]
Undivided interest percentage in each asset category that PPL subsidiary holds		40.00%	41.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	1,402	$ 1,315	$ 1,289	1,402	1,315
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	1,402	1,315	1,289
Balance at end of period		1,402	1,315
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		$ 21	66
Amount to be contributed to plan in the next fiscal year				0
Expected amount of benefit payments in the next period for non-qualified plans				4
Estimated Future Benefit Payments (Details) [Abstract]
2,018				109
2,019				113
2,020				114
2,021				115
2,022				116
2023-2027				573
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Subsequent Event [Member]
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions	105
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member]
Information About Plan Assets (Numeric) [Abstract]
Value of plan U.S. pension trust assets that relate to PPL subsidiary				1,400	$ 1,300
Assumptions Used in Calculations (Numeric) [Abstract]
The limited lives of four partnership of private equity investments (in years)		10 years
The amount of potential liability that maybe required to be funded by the master trust during life of the partnership				$ 28
Number Of Days Notice Required To Redeem Shares		45 days
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				100.00%	100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,561	$ 3,381	3,381	$ 3,561	$ 3,381
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	3,561	3,381
Balance at end of period		3,561	3,381
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	716	714	714	716	714
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	716	714
Balance at end of period		716	714
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	931	909	909	931	909
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	931	909
Balance at end of period		931	909
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	37	40	42	37	40
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	37	40	42
Actual return on plan assets relating to assets still held at the reporting date		1	1
Purchases, sales and settlements		(4)	(3)
Balance at end of period		37	40
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				301	181
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				301	181
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				229	152
Measured at fair value using net asset value per share				364	272
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				229	152
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | International Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				538	551
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				611	546
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				186	381
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				186	381
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				883	850
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				870	837
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				13	13
Fair value at end of period			10
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period			10
Actual return on plan assets relating to assets still held at the reporting date		0	0
Purchases, sales and settlements		0	3
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				10	8
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				10	8
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				109	102
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Private Equity Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				80	80
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Hedge Fund Of Funds Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				175	167
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				50	61
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				50	61
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				1	3
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				1	3
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				24	27
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				24	27
Fair value at end of period			32
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period			32
Actual return on plan assets relating to assets still held at the reporting date		1	1
Purchases, sales and settlements		(4)	(6)
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	72	(15)	(15)	72	(15)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	72	(15)
Balance at end of period		72	(15)
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	(145)	(123)	(123)	(145)	(123)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	(145)	(123)
Balance at end of period		(145)	(123)
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,488	3,243	3,243	$ 3,488	$ 3,243
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	3,488	3,243
Balance at end of period		3,488	3,243
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				56.00%	52.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				55.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				32.00%	30.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				14.00%	12.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				10.00%	10.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				43.00%	46.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				43.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				39.00%	43.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Derivatives [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				4.00%	3.00%
LG And E And KU Energy LLC [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Liquidity Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				1.00%	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				2.00%
LG And E And KU Energy LLC [Member] | Other Postretirement Benefits Plan [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	116	98	88	$ 116	$ 98
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	116	98	88
Balance at end of period		116	98
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		15	20
Amount to be contributed to plan in the next fiscal year				14
Estimated Future Benefit Payments (Details) [Abstract]
2,018				14
2,019				15
2,020				16
2,021				16
2,022				16
2023-2027				79
Expected Federal Subsidy (Details) [Abstract]
Federal subsidy 2018				0
Federal subsidy 2019				0
Federal subsidy 2020				1
Federal subsidy 2021				0
Federal subsidy 2022				0
Federal subsidy 2023-2027				2
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	325	318	297	325	318
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	325	318	297
Balance at end of period		325	318
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions		$ 0	$ 35
Amount to be contributed to plan in the next fiscal year				0
Estimated Future Benefit Payments (Details) [Abstract]
2,018				26
2,019				26
2,020				26
2,021				25
2,022				24
2023-2027				104
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Subsequent Event [Member]
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Employer contributions	54
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member]
Information About Plan Assets (Numeric) [Abstract]
Value of plan U.S. pension trust assets that relate to PPL subsidiary				325	$ 318
Undivided interest percentage in each asset category that PPL subsidiary holds		9.00%	10.00%
Assumptions Used in Calculations (Numeric) [Abstract]
The limited lives of four partnership of private equity investments (in years)		10 years
The amount of potential liability that maybe required to be funded by the master trust during life of the partnership				$ 28
Number Of Days Notice Required To Redeem Shares		45 days
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				100.00%	100.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				100.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,561	$ 3,381	$ 3,381	$ 3,561	$ 3,381
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	3,561	3,381
Balance at end of period		3,561	3,381
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	716	714	714	716	714
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	716	714
Balance at end of period		716	714
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	931	909	909	931	909
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	931	909
Balance at end of period		931	909
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	37	40	42	37	40
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	37	40	42
Actual return on plan assets relating to assets still held at the reporting date		1	1
Purchases, sales and settlements		(4)	(3)
Balance at end of period		37	40
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				301	181
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				301	181
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Cash And Cash Equivalents [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				229	152
Measured at fair value using net asset value per share				364	272
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				229	152
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | International Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				538	551
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Commingled Debt Equity Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				611	546
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				186	381
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				186	381
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | US Treasury And US Government Sponsored Agency Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				883	850
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				870	837
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				13	13
Fair value at end of period			10
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period			10
Actual return on plan assets relating to assets still held at the reporting date		0	0
Purchases, sales and settlements		0	3
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				10	8
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				10	8
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Debt Securities [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Real Estate Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				109	102
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Private Equity Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				80	80
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Hedge Fund Of Funds Alternative Investments [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value using net asset value per share				175	167
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				50	61
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				50	61
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Interest Rate Swaps And Swaptions Derivatives [ Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				1	3
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				1	3
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Other Derivatives [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				24	27
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 1 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 2 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				0	0
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Insurance Contracts [Member] | Level 3 [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Measured at fair value not using net asset value per share				24	27
Fair value at end of period			32
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period			32
Actual return on plan assets relating to assets still held at the reporting date		1	1
Purchases, sales and settlements		(4)	(6)
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Receivables And Payables Net [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	72	(15)	(15)	72	(15)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	72	(15)
Balance at end of period		72	(15)
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Account 401 H [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	(145)	(123)	(123)	(145)	(123)
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	(145)	(123)
Balance at end of period		(145)	(123)
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Total Trust Assets Not Including 401 H Assets [Member]
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,488	3,243	3,243	$ 3,488	$ 3,243
Change in Fair Value of Level 3 Plan Assets [Roll Forward]
Balance at beginning of period	$ 3,488	3,243
Balance at end of period		$ 3,488	$ 3,243
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				56.00%	52.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				55.00%
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Equity Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				32.00%	30.00%
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				14.00%	12.00%
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Growth Portfolio [Member] | Alternative Investments [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				10.00%	10.00%
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				43.00%	46.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				43.00%
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Debt Securities [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				39.00%	43.00%
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Immunizing Portfolio [Member] | Derivatives [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				4.00%	3.00%
Louisville Gas And Electric Co [Member] | Pension Plan [Member] | U.S. [Member] | Master Trust [Member] | Liquidity Portfolio [Member]
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets				1.00%	2.00%
Target Allocations (Details ) [Abstract]
Target asset allocation				2.00%

Retirement and Postemployment81

Retirement and Postemployment Benefits (Savings Plans and Employee Stock Ownership Plan) (Details) - Deferred Savings Plans 401K [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Employer contributions to deferred savings plans	$ 36	$ 35	$ 34
PPL Electric Utilities Corp [Member]
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Employer contributions to deferred savings plans	6	6	6
LG And E And KU Energy LLC [Member]
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Employer contributions to deferred savings plans	18	17	16
Louisville Gas And Electric Co [Member]
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Employer contributions to deferred savings plans	5	5	5
Kentucky Utilities Co [Member]
Defined Contribution Pension And Other Postretirement Plans [Line Items]
Employer contributions to deferred savings plans	$ 4	$ 4	$ 4

Jointly Owned Facilities (Detai

Jointly Owned Facilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Trimble County Unit 1 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	75.00%	75.00%
Electric plant	$ 427	$ 407
Accumulated depreciation	69	55
Construction work in progress	$ 1	$ 1
Trimble County Unit 2 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	75.00%	75.00%
Electric plant	$ 1,032	$ 1,026
Accumulated depreciation	176	161
Construction work in progress	$ 198	$ 83
LG And E And KU Energy LLC [Member] | Trimble County Unit 1 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	75.00%	75.00%
Electric plant	$ 427	$ 407
Accumulated depreciation	69	55
Construction work in progress	$ 1	$ 1
LG And E And KU Energy LLC [Member] | Trimble County Unit 2 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	75.00%	75.00%
Electric plant	$ 1,032	$ 1,026
Accumulated depreciation	176	161
Construction work in progress	$ 198	$ 83
Louisville Gas And Electric Co [Member] | E W Brown Units 6 And 7 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	38.00%	38.00%
Electric plant	$ 41	$ 40
Accumulated depreciation	17	15
Construction work in progress	$ 0	$ 0
Louisville Gas And Electric Co [Member] | Paddys Run Unit 13 And E W Brown Unit 5 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	53.00%	53.00%
Electric plant	$ 52	$ 55
Accumulated depreciation	15	12
Construction work in progress	$ 0	$ 1
Louisville Gas And Electric Co [Member] | Trimble County Unit 1 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	75.00%	75.00%
Electric plant	$ 427	$ 407
Accumulated depreciation	69	55
Construction work in progress	$ 1	$ 1
Louisville Gas And Electric Co [Member] | Trimble County Unit 2 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	14.25%	14.25%
Electric plant	$ 215	$ 214
Accumulated depreciation	36	32
Construction work in progress	$ 102	$ 43
Louisville Gas And Electric Co [Member] | Trimble County Units 5 And 6 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	29.00%	29.00%
Electric plant	$ 32	$ 30
Accumulated depreciation	9	8
Construction work in progress	$ 0	$ 1
Louisville Gas And Electric Co [Member] | Trimble County Units 7 Through 10 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	37.00%	37.00%
Electric plant	$ 73	$ 71
Accumulated depreciation	21	17
Construction work in progress	$ 0	$ 1
Louisville Gas And Electric Co [Member] | Cane Run Unit 7 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	22.00%	22.00%
Electric plant	$ 120	$ 114
Accumulated depreciation	8	5
Construction work in progress	$ 1	$ 2
Louisville Gas And Electric Co [Member] | E W Brown Solar Unit [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	39.00%	39.00%
Electric plant	$ 10	$ 10
Accumulated depreciation	1	0
Construction work in progress	$ 0	$ 0
Kentucky Utilities Co [Member] | E W Brown Units 6 And 7 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	62.00%	62.00%
Electric plant	$ 66	$ 65
Accumulated depreciation	27	23
Construction work in progress	$ 0	$ 0
Kentucky Utilities Co [Member] | Paddys Run Unit 13 And E W Brown Unit 5 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	47.00%	47.00%
Electric plant	$ 46	$ 50
Accumulated depreciation	13	11
Construction work in progress	$ 0	$ 1
Kentucky Utilities Co [Member] | Trimble County Unit 2 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	60.75%	60.75%
Electric plant	$ 817	$ 812
Accumulated depreciation	140	129
Construction work in progress	$ 96	$ 40
Kentucky Utilities Co [Member] | Trimble County Units 5 And 6 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	71.00%	71.00%
Electric plant	$ 76	$ 74
Accumulated depreciation	20	19
Construction work in progress	$ 0	$ 0
Kentucky Utilities Co [Member] | Trimble County Units 7 Through 10 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	63.00%	63.00%
Electric plant	$ 120	$ 121
Accumulated depreciation	34	29
Construction work in progress	$ 0	$ 1
Kentucky Utilities Co [Member] | Cane Run Unit 7 [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	78.00%	78.00%
Electric plant	$ 431	$ 412
Accumulated depreciation	31	18
Construction work in progress	$ 4	$ 4
Kentucky Utilities Co [Member] | E W Brown Solar Unit [Member]
Jointly Owned Facilities [Line Items]
Ownership interest	61.00%	61.00%
Electric plant	$ 16	$ 15
Accumulated depreciation	1	0
Construction work in progress	$ 0	$ 0

Commitments and Contingencies83

Commitments and Contingencies (Energy Purchases, Energy Sales, Other Commitments and Legal Matters) (Details) $ in Millions	1 Months Ended		12 Months Ended
	Jun. 30, 2015coal-fired_unit	Mar. 31, 2015coal-fired_unit	Dec. 31, 2017USD ($)claimresidentmi	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
LKE [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Expiration date of the power purchase agreement with OVEC			Jun. 30, 2040
LKE [Member] | Power Purchase [Member]
Energy Purchase Commitments (Numeric) [Abstract]
2,018			$ 29
2,019			27
2,020			26
2,021			27
2,022			27
Thereafter			457
Total future obligation			593
Purchases			$ 20	$ 23	$ 22
LGE [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of residents that filed class action suit | resident			6
Number of miles within plant that would include a class of residents | mi			4
Number of remaining unresolved Clean Air Act violation claims after July 2014 court ruling | claim			1
Generating units retired at the Cane Run plant | coal-fired_unit	2	1
LGE [Member] | Minimum [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of miles within plant that would include a class of residents | mi			1
LGE [Member] | Maximum [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of miles within plant that would include a class of residents | mi			3
LGE and KU [Member] | Natural Gas Fuel Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
LGE and KU [Member] | Natural Gas Retail Supply Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
LGE and KU [Member] | Coal [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,023
LGE and KU [Member] | Coal Transportation And Fleeting Services [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,024
LGE and KU [Member] | Natural Gas Transportation [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,026
LG And E And KU Energy LLC [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Expiration date of the power purchase agreement with OVEC			Jun. 30, 2040
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of miles within plant that would include a class of residents | mi			4
LG And E And KU Energy LLC [Member] | Power Purchase [Member]
Energy Purchase Commitments (Numeric) [Abstract]
2,018			$ 29
2,019			27
2,020			26
2,021			27
2,022			27
Thereafter			457
Total future obligation			593
Purchases			$ 20	23	22
LG And E And KU Energy LLC [Member] | LGE [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of residents that filed class action suit | resident			6
Number of remaining unresolved Clean Air Act violation claims after July 2014 court ruling | claim			1
Generating units retired at the Cane Run plant | coal-fired_unit	2	1
LG And E And KU Energy LLC [Member] | LGE [Member] | Minimum [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of miles within plant that would include a class of residents | mi			1
LG And E And KU Energy LLC [Member] | LGE [Member] | Maximum [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of miles within plant that would include a class of residents | mi			3
LG And E And KU Energy LLC [Member] | LGE and KU [Member] | Natural Gas Fuel Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
LG And E And KU Energy LLC [Member] | LGE and KU [Member] | Natural Gas Retail Supply Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
LG And E And KU Energy LLC [Member] | LGE and KU [Member] | Coal [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,023
LG And E And KU Energy LLC [Member] | LGE and KU [Member] | Coal Transportation And Fleeting Services [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,024
LG And E And KU Energy LLC [Member] | LGE and KU [Member] | Natural Gas Transportation [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,026
LOUISVILLE GAS And ELECTRIC CO [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Expiration date of the power purchase agreement with OVEC			Jun. 30, 2040
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of residents that filed class action suit | resident			6
Number of miles within plant that would include a class of residents | mi			4
Number of remaining unresolved Clean Air Act violation claims after July 2014 court ruling | claim			1
Generating units retired at the Cane Run plant | coal-fired_unit	2	1
LOUISVILLE GAS And ELECTRIC CO [Member] | Minimum [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of miles within plant that would include a class of residents | mi			1
LOUISVILLE GAS And ELECTRIC CO [Member] | Maximum [Member]
Legal Matters - Cane Run Environmental Claims (Numeric) [Abstract]
Number of miles within plant that would include a class of residents | mi			3
LOUISVILLE GAS And ELECTRIC CO [Member] | Power Purchase [Member]
Energy Purchase Commitments (Numeric) [Abstract]
2,018			$ 20
2,019			19
2,020			18
2,021			19
2,022			19
Thereafter			316
Total future obligation			411
Purchases			$ 14	16	15
LOUISVILLE GAS And ELECTRIC CO [Member] | Natural Gas Fuel Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
LOUISVILLE GAS And ELECTRIC CO [Member] | Natural Gas Retail Supply Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
LOUISVILLE GAS And ELECTRIC CO [Member] | Coal [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,023
LOUISVILLE GAS And ELECTRIC CO [Member] | Coal Transportation And Fleeting Services [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,024
LOUISVILLE GAS And ELECTRIC CO [Member] | Natural Gas Transportation [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,026
Kentucky Utilities Co [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Expiration date of the power purchase agreement with OVEC			Jun. 30, 2040
Kentucky Utilities Co [Member] | Power Purchase [Member]
Energy Purchase Commitments (Numeric) [Abstract]
2,018			$ 9
2,019			8
2,020			8
2,021			8
2,022			8
Thereafter			141
Total future obligation			182
Purchases			$ 6	$ 7	$ 7
Kentucky Utilities Co [Member] | Natural Gas Fuel Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
Kentucky Utilities Co [Member] | Natural Gas Retail Supply Purchase Contracts [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,019
Kentucky Utilities Co [Member] | Coal [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,023
Kentucky Utilities Co [Member] | Coal Transportation And Fleeting Services [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,024
Kentucky Utilities Co [Member] | Natural Gas Transportation [Member]
Energy Purchase Commitments (Numeric) [Abstract]
Maximum maturity date			2,026

Commitments and Contingencies84

Commitments and Contingencies (Environmental Matter and Other) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)employees
Other - Labor Union Agreements (Numeric) [Abstract]
Collective Bargaining Agreement Term	5 years
PPL Electric [Member] | PPL Electric Additional Sites [Member]
Environmental Matters - Superfund And Other Remediation (Numeric) [Abstract]
Environmental site accrual | $	$ 10
PPL Electric Utilities Corp [Member]
Other - Labor Union Agreements (Numeric) [Abstract]
Number Of Union Employees	1,400
Collective Bargaining Agreement Term	5 years
PPL Electric Utilities Corp [Member] | PPL Electric Additional Sites [Member]
Environmental Matters - Superfund And Other Remediation (Numeric) [Abstract]
Environmental site accrual | $	$ 10
LG And E And KU Energy LLC [Member] | LGE [Member]
Other - Labor Union Agreements (Numeric) [Abstract]
Number Of Union Employees	671
Collective Bargaining Agreement Term	3 years
LG And E And KU Energy LLC [Member] | KU [Member]
Other - Labor Union Agreements (Numeric) [Abstract]
Number Of Union Employees	54
Collective Bargaining Agreement Term	3 years
Louisville Gas And Electric Co [Member]
Other - Labor Union Agreements (Numeric) [Abstract]
Number Of Union Employees	671
Collective Bargaining Agreement Term	3 years
Kentucky Utilities Co [Member]
Other - Labor Union Agreements (Numeric) [Abstract]
Number Of Union Employees	54
Collective Bargaining Agreement Term	3 years

Commitments and Contingencies85

Commitments and Contingencies (Guarantees and Other Assurances) (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2018	Dec. 31, 2017USD ($)Integer	Dec. 31, 2016USD ($)
Guarantor Obligations [Line Items]
Recorded liability for all guarantees		$ 17	$ 22
Other Guarantee (Numeric) [Abstract]
Maximum aggregate coverage bodily injury and property damage		$ 225
PPL Guarantee [Member] | Indemnification Guarantee [Member] | Indemnifications Related To WPD Midlands Acquisition [Member]
Guarantor Obligations [Line Items]
Maximum exposure is not estimateable		The maximum exposure and expiration of these indemnifications cannot be estimated because the maximum potential liability is not capped and the expiration date is not specified in the transaction documents.
PPL Guarantee [Member] | Indemnification Guarantee [Member] | WPD Indemnifications For Entities In Liquidation Sales Of Assets [Member]
Guarantor Obligations [Line Items]
Maximum exposure		$ 11
Expiration date		2,020
Minimum period that indemnifications generally expire (in years) | Integer		2
Maximum period that indemnifications generally expire (in years) | Integer		7
PPL Guarantee [Member] | Financial Guarantee [Member] | WPD Guarantee Of Pension And Other Obligations Of Unconsolidated Entities [Member]
Guarantor Obligations [Line Items]
Maximum exposure		$ 95
PPL Electric Guarantee [Member] | Indemnification Guarantee [Member] | Guarantee Of Inventory Value [Member]
Guarantor Obligations [Line Items]
Maximum exposure		$ 16
Expiration date		2,018
PPL Electric Guarantee [Member] | Indemnification Guarantee [Member] | Guarantee Of Inventory Value [Member] | Subsequent Event [Member]
Guarantor Obligations [Line Items]
Expiration date	2,020
LKE Guarantee [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member]
Guarantor Obligations [Line Items]
Maximum exposure		$ 201
Term of guarantee (in years)		12 years
Maximum exposure of guarantee related to terminated lease specific to operational, regulatory and environmental issues		$ 200
Maximum exposure of other guarantees expiring related to a terminated lease		$ 100
LKE Guarantee [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member] | Minimum [Member]
Guarantor Obligations [Line Items]
Expiration date		2,021
LKE Guarantee [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member] | Maximum [Member]
Guarantor Obligations [Line Items]
Expiration date		2,023
LGE And KU Guarantee [Member] | Financial Guarantee [Member] | LGE And KU Guarantee Of Shortfall Related To OVEC [Member]
Guarantor Obligations [Line Items]
Maximum exposure is not estimateable		The maximum exposure and the expiration date of these potential obligations are not presently determinable.
Contingent potential proportionate share of OVEC's outstanding debt		$ 117
PPL Electric Utilities Corp [Member] | Indemnification Guarantee [Member] | Guarantee Of Inventory Value [Member]
Guarantor Obligations [Line Items]
Maximum exposure		$ 16
Expiration date		2,018
PPL Electric Utilities Corp [Member] | Indemnification Guarantee [Member] | Guarantee Of Inventory Value [Member] | Subsequent Event [Member]
Guarantor Obligations [Line Items]
Expiration date	2,020
LG And E And KU Energy LLC [Member]
Guarantor Obligations [Line Items]
Recorded liability for all guarantees		$ 11	$ 17
LG And E And KU Energy LLC [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member]
Guarantor Obligations [Line Items]
Maximum exposure		$ 201
Term of guarantee (in years)		12 years
Maximum exposure of guarantee related to terminated lease specific to operational, regulatory and environmental issues		$ 200
Maximum exposure of other guarantees expiring related to a terminated lease		$ 100
LG And E And KU Energy LLC [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member] | Minimum [Member]
Guarantor Obligations [Line Items]
Expiration date		2,021
LG And E And KU Energy LLC [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member] | Maximum [Member]
Guarantor Obligations [Line Items]
Expiration date		2,023
LG And E And KU Energy LLC [Member] | Financial Guarantee [Member] | LGE And KU Guarantee Of Shortfall Related To OVEC [Member]
Guarantor Obligations [Line Items]
Contingent potential proportionate share of OVEC's outstanding debt		$ 117
Louisville Gas And Electric Co [Member] | LGE And KU Guarantee [Member] | Financial Guarantee [Member] | LGE And KU Guarantee Of Shortfall Related To OVEC [Member]
Guarantor Obligations [Line Items]
Contingent potential proportionate share of OVEC's outstanding debt		81
Kentucky Utilities Co [Member] | LGE And KU Guarantee [Member] | Financial Guarantee [Member] | LGE And KU Guarantee Of Shortfall Related To OVEC [Member]
Guarantor Obligations [Line Items]
Contingent potential proportionate share of OVEC's outstanding debt		$ 36

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
PPL Electric Utilities Corp [Member] | PPL Services [Member]
Support Costs (Details) [Abstract]
Support cost allocations from subsidiary of parent to registrant	$ 182	$ 132	$ 125
PPL Electric Utilities Corp [Member] | PPL EU Services [Member]
Support Costs (Details) [Abstract]
Support cost allocations from subsidiary of parent to registrant	64	69	60
PPL Electric Utilities Corp [Member] | PPL Energy Funding [Member]
Intercompany Borrowings (Numeric) [Abstract]
Intercompany note with affiliate maximum borrowing capacity	400
Notes Receivable, Related Parties, Current	0	0
LG And E And KU Energy LLC [Member]
Intercompany Borrowings (Numeric) [Abstract]
Notes payable to affiliates	225	163
Long-term debt to affiliate	400	400
Interest Expense, Related Party	18	17	3
LG And E And KU Energy LLC [Member] | PPL Services [Member]
Support Costs (Details) [Abstract]
Support cost allocations from subsidiary of parent to registrant	$ 20	$ 18	16
LG And E And KU Energy LLC [Member] | PPL Energy Funding [Member]
Intercompany Borrowings (Numeric) [Abstract]
Intercompany borrowings demand note rate on outstanding borrowing	2.87%	2.12%
Notes payable to affiliates	$ 225	$ 163
Intercompany note with affiliate maximum borrowing capacity	275
Intercompany Note Affiliate Maximum Borrowing Capacity Increase	$ 50
LG And E And KU Energy LLC [Member] | PPL Affiliate [Member]
Intercompany Borrowings (Numeric) [Abstract]
Debt Instrument, Term	10 years
Intercompany borrowings demand note rate on outstanding borrowing	3.50%
Long-term debt to affiliate	$ 400
Interest Expense, Related Party	14	14
LG And E And KU Energy LLC [Member] | PPL Affiliate [Member]
Intercompany Borrowings (Numeric) [Abstract]
Intercompany note with affiliate maximum borrowing capacity	300
Long-term debt to affiliate	0	0
Louisville Gas And Electric Co [Member]
Intercompany Billings by LKS (Details) [Abstract]
Intercompany billings between affiliates	169	178	155
Louisville Gas And Electric Co [Member] | Parent And Affiliate [Member]
Intercompany Borrowings (Numeric) [Abstract]
Notes payable to affiliates	0	0
Intercompany Money Pool Agreement Maximum Borrowing Capacity	500
Kentucky Utilities Co [Member]
Intercompany Billings by LKS (Details) [Abstract]
Intercompany billings between affiliates	190	194	$ 185
Kentucky Utilities Co [Member] | Parent And Affiliate [Member]
Intercompany Borrowings (Numeric) [Abstract]
Notes payable to affiliates	0	$ 0
Intercompany Money Pool Agreement Maximum Borrowing Capacity	$ 500

Other Income (Expense) - net (D

Other Income (Expense) - net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income [Line Items]
Economic foreign currency exchange contracts	$ (261)	$ 384	$ 122
Interest income	2	3	4
Allowance for funds used during construction - equity component	16	19	14
Miscellaneous	17	6	6
Total Other Income	(226)	412	146
Other Expense [Line Items]
Charitable contributions	8	9	21
Miscellaneous	21	13	17
Total Other Expense	29	22	38
Other Income (Expense) - net	$ (255)	$ 390	$ 108

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured on Recurring Basis Table) (Details) - Recurring [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 485	$ 341
Restricted cash and cash equivalents	26	26
Price risk management assets:
Foreign currency contracts	163	211
Cross-currency swaps	101	188
Total price risk management assets	264	399
Total assets	775	766
Price risk management liabilities:
Interest rate swaps	26	31
Foreign currency contracts	148	27
Total price risk management liabilities	174	58
Level 1 [Member]
Assets
Cash and cash equivalents	485	341
Restricted cash and cash equivalents	26	26
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total assets	511	367
Price risk management liabilities:
Interest rate swaps	0	0
Foreign currency contracts	0	0
Total price risk management liabilities	0	0
Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Price risk management assets:
Foreign currency contracts	163	211
Cross-currency swaps	101	188
Total price risk management assets	264	399
Total assets	264	399
Price risk management liabilities:
Interest rate swaps	26	31
Foreign currency contracts	148	27
Total price risk management liabilities	174	58
Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Price risk management assets:
Foreign currency contracts	0	0
Cross-currency swaps	0	0
Total price risk management assets	0	0
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	0	0
Foreign currency contracts	0	0
Total price risk management liabilities	0	0
PPL Electric Utilities Corp [Member]
Assets
Cash and cash equivalents	49	13
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total assets	51	15
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	49	13
Restricted cash and cash equivalents	2	2
Price risk management assets:
Total assets	51	15
PPL Electric Utilities Corp [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Price risk management assets:
Total assets	0	0
PPL Electric Utilities Corp [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Restricted cash and cash equivalents	0	0
Price risk management assets:
Total assets	0	0
LG And E And KU Energy LLC [Member]
Assets
Cash and cash equivalents	30	13
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	30	16
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	30	13
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	30	16
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
LG And E And KU Energy LLC [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Cash collateral posted to counterparties	0	0
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
LG And E And KU Energy LLC [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Cash collateral posted to counterparties	0	0
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
Louisville Gas And Electric Co [Member]
Assets
Cash and cash equivalents	15	5
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	15	8
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	15	5
Price risk management assets:
Cash collateral posted to counterparties	0	3
Total assets	15	8
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
Louisville Gas And Electric Co [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Cash collateral posted to counterparties	0	0
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	26	31
Total price risk management liabilities	26	31
Louisville Gas And Electric Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Cash collateral posted to counterparties	0	0
Total assets	0	0
Price risk management liabilities:
Interest rate swaps	0	0
Total price risk management liabilities	0	0
Kentucky Utilities Co [Member]
Assets
Cash and cash equivalents	15	7
Price risk management assets:
Total assets	15	7
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	15	7
Price risk management assets:
Total assets	15	7
Kentucky Utilities Co [Member] | Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total assets	0	0
Kentucky Utilities Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Price risk management assets:
Total assets	$ 0	$ 0

Fair Value Measurements (Financ

Fair Value Measurements (Financial Instruments Not Recorded at Fair Value) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	$ 20,195	$ 18,326
Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	23,783	21,355
PPL Electric Utilities Corp [Member] | Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	3,298	2,831
PPL Electric Utilities Corp [Member] | Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	3,769	3,148
LG And E And KU Energy LLC [Member] | Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	5,159	5,065
LG And E And KU Energy LLC [Member] | Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	5,670	5,439
Louisville Gas And Electric Co [Member] | Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	1,709	1,617
Louisville Gas And Electric Co [Member] | Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	1,865	1,710
Kentucky Utilities Co [Member] | Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	2,328	2,327
Kentucky Utilities Co [Member] | Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	$ 2,605	$ 2,514

Derivative Instruments and He90

Derivative Instruments and Hedging Activities (Intro) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Master Netting Arrangements (Numeric) [Line Items]
Cash Collateral Obligation Under Master Netting Arrangement	$ 20	$ 19
Cash Collateral Posted Under Master Netting Arrangements	0	3
LG And E And KU Energy LLC [Member]
Master Netting Arrangements (Numeric) [Line Items]
Cash Collateral Obligation Under Master Netting Arrangement	0	0
Cash Collateral Posted Under Master Netting Arrangements	0	3
Louisville Gas And Electric Co [Member]
Master Netting Arrangements (Numeric) [Line Items]
Cash Collateral Obligation Under Master Netting Arrangement	0	0
Cash Collateral Posted Under Master Netting Arrangements	0	3
Kentucky Utilities Co [Member]
Master Netting Arrangements (Numeric) [Line Items]
Cash Collateral Obligation Under Master Netting Arrangement	0	0
Cash Collateral Posted Under Master Netting Arrangements	$ 0	$ 0

Derivative Instruments and He91

Derivative Instruments and Hedging Activities (Risk Disclosures) (Details) $ in Millions, £ in Billions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2017GBP (£)	Sep. 30, 2016GBP (£)
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ (2)	$ 9	$ 101
Cash Flow Hedges [Member]
Interest Rate Risk - Cash Flow Hedges (Numeric) [Abstract]
Insignificant or no hedge ineffectiveness associated with interest rate cash flow hedges			For 2017, PPL had no hedge ineffectiveness associated with interest rate derivatives. For 2016 and 2015, hedge ineffectiveness associated with interest rate derivatives was insignificant.
No or insignificant after-tax gains (losses) previously recorded in AOCI reclassified to earnings related to interest rate cash flow hedge contracts			PPL had an insignificant amount of cash flow hedges reclassified into earnings associated with discontinued cash flow hedges in 2017 and 2016. As a result of the June 1, 2015 spinoff of PPL Energy Supply, all PPL cash flow hedges associated with PPL Energy Supply were ineffective and discontinued and therefore, reclassified into earnings during the second quarter of 2015 and reflected in discontinued operations for 2015. See Note 8 for additional information. PPL had no other cash flow hedges reclassified into earnings associated with discontinued cash flow hedges in 2015.
Interest Rate Cash Flow Hedge Gain (Loss) To Be Reclassified During Next 12 Months Insignificant			insignificant.
Cash Flow Hedges [Member] | Cross Currency Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	$ 702		$ 702
Interest Rate Risk - Cash Flow Hedges (Numeric) [Abstract]
Earliest maturity date of cross-currency cash flow hedge contracts			2,021
Latest maturity date of cross-currency cash flow hedge contracts			2,028
Repayment Of Senior Debt Related To Matured Cash Flow Hedge	100
Derivative, Notional Amount Matured	100		$ 100
Gain (loss) recognized in income upon settlement of cross-currency interest rate swap contracts			19
Economic Hedges [Member] | Foreign Currency Contracts [Member]
Foreign Currency Risk - Economic Activity (Numeric) [Abstract]
Total exposure hedged related to foreign currency contracts for anticipated earnings hedges classified as economic activity	3,500		$ 3,500			£ 2.6
Earliest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity			Jan. 31, 2018
Latest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity			Jun. 30, 2020
Economic Hedges [Member] | Foreign Currency Contracts [Member] | Hedges 2017 and 2018 [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount		$ 2,000					£ 1.3
Foreign Currency Risk - Economic Activity (Numeric) [Abstract]
Earliest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity		Jan. 31, 2017
Latest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity		Nov. 30, 2018
Derivative Cash Received On Hedge		$ 310
Net Investment Hedges [Member] | Foreign Currency Contracts [Member]
Foreign Currency Risk - Net Investment Hedges (Numeric) [Abstract]
Net after tax gains (losses) on net investment hedges recognized in the foreign currency translation adjustment component of AOCI			$ 22	21
LGE [Member] | Economic Hedges [Member] | Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	147		$ 147
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of terminated swaps				32
Net cash settlements on terminated interest rate swaps				9
Year of expiration of the maximum maturity date of interest rate economic activity contracts			2,033
LG And E And KU Energy LLC [Member]
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ 0	9	88
LG And E And KU Energy LLC [Member] | LGE [Member] | Economic Hedges [Member] | Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	147		$ 147
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of terminated swaps				32
Net cash settlements on terminated interest rate swaps				9
Year of expiration of the maximum maturity date of interest rate economic activity contracts			2,033
Louisville Gas And Electric Co [Member]
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ 0	9	44
Louisville Gas And Electric Co [Member] | Economic Hedges [Member] | Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	$ 147		$ 147
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of terminated swaps				32
Net cash settlements on terminated interest rate swaps				9
Year of expiration of the maximum maturity date of interest rate economic activity contracts			2,033
Kentucky Utilities Co [Member]
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ 0	$ 0	$ 44

Derivative Instruments and He92

Derivative Instruments and Hedging Activities (Fair Values) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivatives Designated As Hedging Instruments [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	$ 101	$ 188
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Current Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	4	32
Derivatives Designated As Hedging Instruments [Member] | Current Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Designated As Hedging Instruments [Member] | Current Assets [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	4	32
Derivatives Designated As Hedging Instruments [Member] | Current Assets [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	97	156
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	97	156
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Designated As Hedging Instruments [Member] | Current Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Not Designated As Hedging Instruments [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	163	211
Liability value	174	58
Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	45	31
Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	45	31
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	118	180
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	118	180
Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	71	25
Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	4	4
Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	67	21
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	103	33
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	22	27
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Cross Currency Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	0	0
Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Foreign Currency Contracts [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	81	6
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Liability value	26	31
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	4	4
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	4	4
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	22	27
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	22	27
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Liability value	26	31
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Assets [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Asset value	0	0
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	4	4
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	4	4
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	22	27
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Noncurrent Liabilities [Member] | Interest Rate Swaps [Member]
Fair Values by Balance Sheet Location [Abstract]
Liability value	$ 22	$ 27

Derivative Instruments and He93

Derivative Instruments and Hedging Activities (Gains and Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flow Hedges [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) reclassified from AOCI into income on derivative (effective portion)	$ (91)	$ 112	$ 53
Gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	0	0	(70)
Cash Flow Hedges [Member] | Other Comprehensive Income [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in OCI on derivative (effective portion)	(98)	109	26
Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Other Comprehensive Income [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in OCI on derivative (effective portion)	0	(21)	(34)
Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Interest Expense [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) reclassified from AOCI into income on derivative (effective portion)	(9)	(7)	(11)
Gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	0	0	0
Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Discontinued Operations [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) reclassified from AOCI into income on derivative (effective portion)			0
Gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)			(77)
Cash Flow Hedges [Member] | Cross Currency Swaps [Member] | Other Comprehensive Income [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in OCI on derivative (effective portion)	(98)	130	60
Cash Flow Hedges [Member] | Cross Currency Swaps [Member] | Other Income (Expense) Net [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) reclassified from AOCI into income on derivative (effective portion)	(82)	116	49
Gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	0	0	0
Cash Flow Hedges [Member] | Cross Currency Swaps [Member] | Interest Expense [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) reclassified from AOCI into income on derivative (effective portion)		3	2
Gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)		0	0
Cash Flow Hedges [Member] | Commodity Contracts [Member] | Discontinued Operations [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) reclassified from AOCI into income on derivative (effective portion)			13
Gain (loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)			7
Net Investment Hedges [Member] | Foreign Currency Contracts [Member] | Other Comprehensive Income [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in OCI on derivative (effective portion)	1	2	9
Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Regulatory Assets Noncurrent [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized as regulatory liabilities/assets	0	0	(22)
Derivatives Not Designated As Hedging Instruments [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in income on derivative	(267)	377	114
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Regulatory Assets Noncurrent [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized as regulatory liabilities/assets	5	7	1
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Interest Expense [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in income on derivative	(6)	(7)	(8)
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Currency Contracts [Member] | Other Income (Expense) Net [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in income on derivative	(261)	384	122
LG And E And KU Energy LLC [Member] | Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Regulatory Assets Noncurrent [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized as regulatory liabilities/assets	0	0	(22)
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Regulatory Assets Noncurrent [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized as regulatory liabilities/assets	5	7	1
LG And E And KU Energy LLC [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Interest Expense [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in income on derivative	(6)	(7)	(8)
Louisville Gas And Electric Co [Member] | Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Regulatory Assets Noncurrent [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized as regulatory liabilities/assets	0	0	(11)
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Regulatory Assets Noncurrent [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized as regulatory liabilities/assets	5	7	1
Louisville Gas And Electric Co [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Interest Expense [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized in income on derivative	(6)	(7)	(8)
Kentucky Utilities Co [Member] | Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Regulatory Assets Noncurrent [Member]
Amounts Included in Income, OCI or Regulatory Liabilities/Assets [Abstract]
Gain (loss) recognized as regulatory liabilities/assets	$ 0	$ 0	$ (11)

Derivative Instruments and He94

Derivative Instruments and Hedging Activities (Offsetting Derivative Instruments and Credit Risk-Related Features) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	$ 51
Aggregate fair value of collateral posted on these derivative instruments	0
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	51
Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	264	$ 399
Derivative instruments eligible for offset - assets	107	27
Cash collateral received eligible for offset - assets	20	19
Net assets	137	353
Gross liabilities	174	58
Derivative instruments eligible for offset - liabilities	107	27
Cash collateral pledged eligible for offset - liabilities	0	3
Net liabilities	67	28
LG And E And KU Energy LLC [Member]
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	10
Aggregate fair value of collateral posted on these derivative instruments	0
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	10
LG And E And KU Energy LLC [Member] | Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	0	0
Derivative instruments eligible for offset - assets	0	0
Cash collateral received eligible for offset - assets	0	0
Net assets	0	0
Gross liabilities	26	31
Derivative instruments eligible for offset - liabilities	0	0
Cash collateral pledged eligible for offset - liabilities	0	3
Net liabilities	26	28
Louisville Gas And Electric Co [Member]
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	10
Aggregate fair value of collateral posted on these derivative instruments	0
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	10
Louisville Gas And Electric Co [Member] | Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	0	0
Derivative instruments eligible for offset - assets	0	0
Cash collateral received eligible for offset - assets	0	0
Net assets	0	0
Gross liabilities	26	31
Derivative instruments eligible for offset - liabilities	0	0
Cash collateral pledged eligible for offset - liabilities	0	3
Net liabilities	$ 26	$ 28

Goodwill and Other Intangible95

Goodwill and Other Intangible Assets (Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	$ 3,060	$ 3,550
Effect of foreign currency exchange rates	198	(490)
Balance at end of period	3,258	3,060
U.K. Regulated [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	2,398	2,888
Effect of foreign currency exchange rates	198	(490)
Balance at end of period	2,596	2,398
Kentucky Regulated [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	662	662
Balance at end of period	662	662
LG And E And KU Energy LLC [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	996
Balance at end of period	996	996
Louisville Gas And Electric Co [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	389
Balance at end of period	389	389
Kentucky Utilities Co [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	607
Balance at end of period	$ 607	$ 607

Goodwill and Other Intangible96

Goodwill and Other Intangible Assets (Other Intangibles) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Subject to amortization: [Abstract]
Gross carrying amount	$ 528	$ 775
Accumulated amortization	190	442
Not subject to amortization due to indefinite life: [Line Items]
Gross carrying amount	359	367
Gross carrying amount - other intangible assets	887	1,142
Land And Transmission Rights [Member]
Not subject to amortization due to indefinite life: [Line Items]
Gross carrying amount	12	19
Easements [Member]
Not subject to amortization due to indefinite life: [Line Items]
Gross carrying amount	347	348
Contracts [Member]
Subject to amortization: [Abstract]
Gross carrying amount	138	405
Accumulated amortization	67	325
Land And Transmission Rights [Member]
Subject to amortization: [Abstract]
Gross carrying amount	382	362
Accumulated amortization	120	115
Emission Allowances And Renewable Energy Credits [Member]
Subject to amortization: [Abstract]
Gross carrying amount	1	2
Accumulated amortization	0	0
Licenses And Other [Member]
Subject to amortization: [Abstract]
Gross carrying amount	7	6
Accumulated amortization	3	2
Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]
Subject to amortization: [Abstract]
Amortization expense	15	30	$ 57
Forecasted amortization in 2018	15
Forecasted amortization in 2019	15
Forecasted amortization in 2020	14
Forecasted amortization in 2021	14
Forecasted amortization in 2022	14
Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]
Subject to amortization: [Abstract]
Amortization expense	6	6	6
Forecasted amortization in 2018	6
Forecasted amortization in 2019	6
Forecasted amortization in 2020	6
Forecasted amortization in 2021	6
Forecasted amortization in 2022	6
Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]
Subject to amortization: [Abstract]
Amortization expense	9	24	51
Forecasted amortization in 2018	9
Forecasted amortization in 2019	9
Forecasted amortization in 2020	8
Forecasted amortization in 2021	8
Forecasted amortization in 2022	8
PPL Electric Utilities Corp [Member]
Subject to amortization: [Abstract]
Gross carrying amount	364	344
Accumulated amortization	118	113
Not subject to amortization due to indefinite life: [Line Items]
Gross carrying amount - other intangible assets	377	364
PPL Electric Utilities Corp [Member] | Land And Transmission Rights [Member]
Not subject to amortization due to indefinite life: [Line Items]
Gross carrying amount	13	20
PPL Electric Utilities Corp [Member] | Land And Transmission Rights [Member]
Subject to amortization: [Abstract]
Gross carrying amount	361	341
Accumulated amortization	117	112
PPL Electric Utilities Corp [Member] | Licenses And Other [Member]
Subject to amortization: [Abstract]
Gross carrying amount	3	3
Accumulated amortization	1	1
LG And E And KU Energy LLC [Member]
Subject to amortization: [Abstract]
Gross carrying amount	147	416
Accumulated amortization	61	321
LG And E And KU Energy LLC [Member] | Coal Contracts [Member]
Subject to amortization: [Abstract]
Gross carrying amount	0	269
Accumulated amortization	0	269
LG And E And KU Energy LLC [Member] | Land And Transmission Rights [Member]
Subject to amortization: [Abstract]
Gross carrying amount	21	21
Accumulated amortization	3	3
LG And E And KU Energy LLC [Member] | Ohio Valley Electric Corporation Power Purchase Agreement [Member]
Subject to amortization: [Abstract]
Gross carrying amount	126	126
Accumulated amortization	58	49
LG And E And KU Energy LLC [Member] | Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]
Subject to amortization: [Abstract]
Amortization expense	9	25	51
LG And E And KU Energy LLC [Member] | Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]
Subject to amortization: [Abstract]
Amortization expense	0	1	0
LG And E And KU Energy LLC [Member] | Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]
Subject to amortization: [Abstract]
Amortization expense	9	24	51
Forecasted amortization in 2018	9
Forecasted amortization in 2019	9
Forecasted amortization in 2020	8
Forecasted amortization in 2021	8
Forecasted amortization in 2022	8
Louisville Gas And Electric Co [Member]
Subject to amortization: [Abstract]
Gross carrying amount	94	218
Accumulated amortization	41	159
Louisville Gas And Electric Co [Member] | Coal Contracts [Member]
Subject to amortization: [Abstract]
Gross carrying amount	0	124
Accumulated amortization	0	124
Louisville Gas And Electric Co [Member] | Land And Transmission Rights [Member]
Subject to amortization: [Abstract]
Gross carrying amount	7	7
Accumulated amortization	1	1
Louisville Gas And Electric Co [Member] | Ohio Valley Electric Corporation Power Purchase Agreement [Member]
Subject to amortization: [Abstract]
Gross carrying amount	87	87
Accumulated amortization	40	34
Louisville Gas And Electric Co [Member] | Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]
Subject to amortization: [Abstract]
Amortization expense	6	13	24
Forecasted amortization in 2018	6
Forecasted amortization in 2019	6
Forecasted amortization in 2020	6
Forecasted amortization in 2021	6
Forecasted amortization in 2022	6
Kentucky Utilities Co [Member]
Subject to amortization: [Abstract]
Gross carrying amount	53	198
Accumulated amortization	20	162
Kentucky Utilities Co [Member] | Coal Contracts [Member]
Subject to amortization: [Abstract]
Gross carrying amount	0	145
Accumulated amortization	0	145
Kentucky Utilities Co [Member] | Land And Transmission Rights [Member]
Subject to amortization: [Abstract]
Gross carrying amount	14	14
Accumulated amortization	2	2
Kentucky Utilities Co [Member] | Ohio Valley Electric Corporation Power Purchase Agreement [Member]
Subject to amortization: [Abstract]
Gross carrying amount	39	39
Accumulated amortization	18	15
Kentucky Utilities Co [Member] | Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]
Subject to amortization: [Abstract]
Amortization expense	3	12	27
Kentucky Utilities Co [Member] | Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]
Subject to amortization: [Abstract]
Amortization expense	0	1	0
Kentucky Utilities Co [Member] | Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]
Subject to amortization: [Abstract]
Amortization expense	3	$ 11	$ 27
Forecasted amortization in 2018	3
Forecasted amortization in 2019	3
Forecasted amortization in 2020	2
Forecasted amortization in 2021	2
Forecasted amortization in 2022	$ 2

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	$ 488	$ 586
Accretion	21	24
Changes in estimated cash flow or settlement date	(73)	(84)
Effect of foreign currency exchange rates	4	(9)
Obligations settled	(43)	(29)
Balance at End of Period	397	488
LG And E And KU Energy LLC [Member]
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	433	535
Accretion	20	22
Changes in estimated cash flow or settlement date	(54)	(95)
Obligations settled	(43)	(29)
Balance at End of Period	356	433
Increase (Decrease) to the asset retirement obligation due to revisions in the amounts and timing of future expected costs related to the closure of CCR impoundments	(60)	114
Louisville Gas And Electric Co [Member]
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	145	175
Accretion	7	7
Changes in estimated cash flow or settlement date	(8)	(19)
Obligations settled	(23)	(18)
Balance at End of Period	121	145
Increase (Decrease) to the asset retirement obligation due to revisions in the amounts and timing of future expected costs related to the closure of CCR impoundments	(8)	(24)
Kentucky Utilities Co [Member]
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	288	360
Accretion	13	15
Changes in estimated cash flow or settlement date	(46)	(76)
Obligations settled	(20)	(11)
Balance at End of Period	235	288
Increase (Decrease) to the asset retirement obligation due to revisions in the amounts and timing of future expected costs related to the closure of CCR impoundments	$ (52)	$ (90)

Accumulated Other Comprehensi98

Accumulated Other Comprehensive Income (Loss) (After-tax Changes by Component) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (3,778)	$ (2,728)	$ (2,274)
Amounts arising during the period	151	(1,080)	(575)
Reclassifications from AOCI	205	30	145
Net OCI during the period	356	(1,050)	(430)
Distribution of PPL Energy Supply			(24)
Balance at end of period	(3,422)	(3,778)	(2,728)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(1,627)	(520)	(286)
Amounts arising during the period	538	(1,107)	(234)
Reclassifications from AOCI	0	0	0
Net OCI during the period	538	(1,107)	(234)
Distribution of PPL Energy Supply			0
Balance at end of period	(1,089)	(1,627)	(520)
Available For Sale Securities Unrealized Gains (Losses) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	0	0	201
Amounts arising during the period	0	0	8
Reclassifications from AOCI	0	0	(2)
Net OCI during the period	0	0	6
Distribution of PPL Energy Supply			(207)
Balance at end of period	0	0	0
Qualifying Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(7)	(7)	20
Amounts arising during the period	(79)	91	26
Reclassifications from AOCI	73	(91)	2
Net OCI during the period	(6)	0	28
Distribution of PPL Energy Supply			(55)
Balance at end of period	(13)	(7)	(7)
Equity Investees AOCI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(1)	0	1
Amounts arising during the period	0	0	0
Reclassifications from AOCI	1	(1)	(1)
Net OCI during the period	1	(1)	(1)
Distribution of PPL Energy Supply			0
Balance at end of period	0	(1)	0
Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(8)	(6)	3
Amounts arising during the period	0	(3)	(9)
Reclassifications from AOCI	1	1	0
Net OCI during the period	1	(2)	(9)
Distribution of PPL Energy Supply			0
Balance at end of period	(7)	(8)	(6)
Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(2,135)	(2,195)	(2,213)
Amounts arising during the period	(308)	(61)	(366)
Reclassifications from AOCI	130	121	146
Net OCI during the period	(178)	60	(220)
Distribution of PPL Energy Supply			238
Balance at end of period	(2,313)	(2,135)	(2,195)
LG And E And KU Energy LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(70)	(46)	(45)
Amounts arising during the period	(25)	(27)	(7)
Reclassifications from AOCI	7	3	6
Net OCI during the period	(18)	(24)	(1)
Balance at end of period	(88)	(70)	(46)
LG And E And KU Energy LLC [Member] | Equity Investees AOCI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(1)	0	0
Amounts arising during the period	0	0	0
Reclassifications from AOCI	1	(1)	0
Net OCI during the period	1	(1)	0
Balance at end of period	0	(1)	0
LG And E And KU Energy LLC [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(8)	(10)	(8)
Amounts arising during the period	(2)	0	(3)
Reclassifications from AOCI	1	2	1
Net OCI during the period	(1)	2	(2)
Balance at end of period	(9)	(8)	(10)
LG And E And KU Energy LLC [Member] | Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(61)	(36)	(37)
Amounts arising during the period	(23)	(27)	(4)
Reclassifications from AOCI	5	2	5
Net OCI during the period	(18)	(25)	1
Balance at end of period	$ (79)	$ (61)	$ (36)

Accumulated Other Comprehensi99

Accumulated Other Comprehensive Income (Loss) (Income (Expense) Effect of Reclassifications) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Affected Line Item on the Statements of Income
Interest Expense	$ (901)	$ (888)	$ (871)
Other Income (Expense) - net	(255)	390	108
Total Pre-tax	1,912	2,550	2,068
Income Taxes	(784)	(648)	(465)
Total After-Tax	1,128	1,902	1,603
Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Total After-Tax	(205)	(30)	(145)
Available For Sale Securities [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Other Income (Expense) - net	0	0	4
Total Pre-tax	0	0	4
Income Taxes	0	0	(2)
Total After-Tax	0	0	2
Qualifying Derivatives [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Total Pre-tax	(91)	112	(17)
Income Taxes	18	(21)	15
Total After-Tax	(73)	91	(2)
Qualifying Derivatives [Member] | Interest Rate Swaps [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Interest Expense	(9)	(7)	(11)
Discontinued operations	0	0	(77)
Qualifying Derivatives [Member] | Cross Currency Swaps [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Interest Expense	0	3	2
Other Income (Expense) - net	(82)	116	49
Qualifying Derivatives [Member] | Commodity Contracts [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Discontinued operations	0	0	20
Equity Investees AOCI [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Other Income (Expense) - net	(1)	1	1
Total Pre-tax	(1)	1	1
Income Taxes	0	0	0
Total After-Tax	(1)	1	1
Defined Benefit Plans [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Total Pre-tax	(169)	(158)	(192)
Income Taxes	38	36	46
Total After-Tax	(131)	(122)	(146)
Defined Benefit Plans [Member] | Prior Service Costs [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Total Pre-tax	(2)	(2)	0
Defined Benefit Plans [Member] | Net Actuarial Loss [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income
Total Pre-tax	$ (167)	$ (156)	$ (192)

New Accounting Guidance Pend100

New Accounting Guidance Pending Adoption New Accounting Guidance Pending Adoption (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Pension Plan [Member] | U.K. [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated Impact Of Adoption Of ASU 2017-07	$ 175	$ 120

SCHEDULE I - CONDENSED UNCON101

SCHEDULE I - CONDENSED UNCONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Revenues [Abstract]
Operating Revenues	$ 1,926	$ 1,845	$ 1,725	$ 1,951	$ 1,832	$ 1,889	$ 1,785	$ 2,011	$ 7,447	$ 7,517	$ 7,669
Operating Expenses [Abstract]
Other operation and maintenance									1,635	1,745	1,938
Total Operating Expenses									4,379	4,469	4,838
Operating Loss	793	777	702	796	714	786	725	823	3,068	3,048	2,831
Other Income (Expense) - net [Abstract]
Other Income (Expense) - net									(255)	390	108
Interest Expense									901	888	871
Income Taxes									784	648	465
Net income	$ 78	$ 355	$ 292	$ 403	$ 465	$ 473	$ 483	$ 481	1,128	1,902	682
Total other comprehensive income (loss)									356	(1,050)	(430)
Comprehensive Income Attributable to PPL Shareowners									$ 1,484	$ 852	$ 252
Net Income Available to PPL Corporation Common Shareowners: (in dollars per share)
Basic	$ 0.11	$ 0.52	$ 0.43	$ 0.59	$ 0.68	$ 0.70	$ 0.71	$ 0.71	$ 1.64	$ 2.80	$ 1.01
Diluted	$ 0.11	$ 0.51	$ 0.43	$ 0.59	$ 0.68	$ 0.69	$ 0.71	$ 0.71	$ 1.64	$ 2.79	$ 1.01
Weighted-Average Shares of Common Stock Outstanding (in thousands)
Basic									685,240	677,592	669,814
Diluted									687,334	680,446	672,586
PPL Corp [Member]
Operating Revenues [Abstract]
Operating Revenues									$ 0	$ 0	$ 0
Operating Expenses [Abstract]
Other operation and maintenance									2	2	9
Total Operating Expenses									2	2	9
Operating Loss									(2)	(2)	(9)
Other Income (Expense) - net [Abstract]
Equity in earnings of subsidiaries									1,175	1,915	711
Other income (expense)									(1)	(1)	(15)
Other Income (Expense) - net									1,174	1,914	696
Interest Expense									8	8	9
Interest Expense with Affiliates									16	10	10
Income Before Income Taxes									1,148	1,894	668
Income Taxes									20	(8)	(14)
Net income									1,128	1,902	682
Total other comprehensive income (loss)									356	(1,050)	(430)
Comprehensive Income Attributable to PPL Shareowners									$ 1,484	$ 852	$ 252
Net Income Available to PPL Corporation Common Shareowners: (in dollars per share)
Basic									$ 1.64	$ 2.80	$ 1.01
Diluted									$ 1.64	$ 2.79	$ 1.01
Weighted-Average Shares of Common Stock Outstanding (in thousands)
Basic									685,240	677,592	669,814
Diluted									687,334	680,446	672,586
L G And E And K U Energy L L C Unconsolidated [Member]
Other Income (Expense) - net [Abstract]
Equity in earnings of subsidiaries									$ 397	$ 452	$ 390
Interest Income from Affiliate									14	9	4
Other Income (Expense) - net									411	461	394
Interest Expense									30	29	39
Interest Expense with Affiliates									20	18	5
Income Before Income Taxes									361	414	350
Income Taxes									45	(15)	(14)
Net income									316	429	364
Total other comprehensive income (loss)									(18)	(24)	(1)
Comprehensive Income Attributable to PPL Shareowners									$ 298	$ 405	$ 363

SCHEDULE I - CONDENSED UNCON102

SCHEDULE I - CONDENSED UNCONSOLIDATED STATEMENTS OF CASH FLOWS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Unconsolidated Financial Statements [Line Items]
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	$ 2,461	$ 2,890	$ 2,272
Cash Flows from Operating Activities [Abstract]
Net cash provided by (used in) operating activities	2,461	2,890	2,615
Cash Flows from Investing Activities [Abstract]
Net cash provided by (used in) investing activities	(3,156)	(2,918)	(3,588)
Cash Flows from Financing Activities [Abstract]
Issuance of equity, net of issuance costs	453	144	203
Net increase (decrease) in short-term debt	115	29	94
Retirement of long-term debt	(168)	(930)	(1,000)
Issuance of long-term debt	1,515	1,342	2,236
Payment of common stock dividends	(1,072)	(1,030)	(1,004)
Other	(19)	6	(47)
Net cash provided by (used in) financing activities - continuing operations	824	(439)	482
Net cash provided by (used in) financing activities	824	(439)	68
Net Increase (Decrease) in Cash and Cash Equivalents	144	(495)	(563)
Cash and Cash Equivalents at Beginning of Period	341	836	1,399
Cash and Cash Equivalents at End of Period	485	341	836
PPL Corp [Member]
Cash Flows from Operating Activities [Abstract]
Net cash provided by (used in) operating activities	1,108	1,563	993
Cash Flows from Investing Activities [Abstract]
Capital contributions to affiliated subsidiaries	(585)	(308)	(491)
Return of capital from affiliated subsidiaries	0	0	112
Net cash provided by (used in) investing activities	(585)	(308)	(379)
Cash Flows from Financing Activities [Abstract]
Issuance of equity, net of issuance costs	453	144	203
Net increase (decrease) in short-term debt with affiliates	113	(341)	215
Payment of common stock dividends	(1,072)	(1,030)	(1,004)
Other	(21)	(24)	(28)
Net cash provided by (used in) financing activities	(527)	(1,251)	(614)
Cash and Cash Equivalents at Beginning of Period	4	0	0
Cash and Cash Equivalents at End of Period	0	4	0
Supplemental Disclosures of Cash Flow Information: [Abstract]
Cash Dividends Received from Subsidiaries	1,253	1,510	1,198
L G And E And K U Energy L L C Unconsolidated [Member]
Condensed Unconsolidated Financial Statements [Line Items]
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	401	285	246
Cash Flows from Investing Activities [Abstract]
Capital contributions to affiliated subsidiaries	(30)	(91)	(140)
Net decrease in notes receivable from affiliates	(28)	47	73
Net cash provided by (used in) investing activities	(58)	(44)	(67)
Cash Flows from Financing Activities [Abstract]
Net increase (decrease) in notes payable to affiliates	58	90	315
Net increase (decrease) in short-term debt	0	(75)	0
Retirement of long-term debt	0	0	(400)
Contributions from member	0	61	125
Distributions to member	(402)	(316)	(219)
Net cash provided by (used in) financing activities	(344)	(240)	(179)
Net Increase (Decrease) in Cash and Cash Equivalents	(1)	1	0
Cash and Cash Equivalents at Beginning of Period	1	0	0
Cash and Cash Equivalents at End of Period	0	1	0
Supplemental Disclosures of Cash Flow Information: [Abstract]
Cash Dividends Received from Subsidiaries	$ 418	$ 376	$ 272

SCHEDULE I - CONDENSED UNCON103

SCHEDULE I - CONDENSED UNCONSOLIDATED BALANCE SHEETS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents		$ 485	$ 341	$ 836	$ 1,399
Accounts Receivable [Abstract]
Other		100	46
Accounts receivable		681	666
Prepayments		66	63
Price risk management assets		49	63
Other current assets		50	52
Total Current Assets		2,294	2,067
Other Noncurrent Assets [Abstract]
Price risk management assets		215	336
Other noncurrent assets		135	151
Total Other Noncurrent Assets		6,093	6,174
Total Assets		41,479	38,315
Current Liabilities [Abstract]
Short-term debt		1,080	923
Long-term debt due within one year		348	518
Dividends		273	259
Taxes		105	101
Other current liabilities		624	569
Total Current Liabilities		4,023	3,837
Long-term Debt [Abstract]
Total Long-term Debt		19,847	17,808
Total Deferred Credits and Other Noncurrent Liabilities		6,848	6,771
Equity [Abstract]
Common stock	[1]	7	7
Additional paid-in capital		10,305	9,841
Earnings reinvested		3,871	3,829
Accumulated other comprehensive loss		(3,422)	(3,778)	(2,728)	(2,274)
Total Equity		10,761	9,899	9,919	13,628
Total Liabilities and Equity		$ 41,479	$ 38,315
PPL Corporation Shareowners' Common Equity Additional Information [Abstract]
Common stock par value		$ 0.01	$ 0.01
Common stock shares authorized		1,560,000	1,560,000
Common stock shares issued		693,398	679,731
Common stock shares outstanding		693,398	679,731
PPL Corp [Member]
Current Assets
Cash and cash equivalents		$ 0	$ 4	0	0
Accounts Receivable [Abstract]
Other		7	7
Accounts receivable from affiliates		17	10
Price risk management assets		196	63
Total Current Assets		220	84
Investments [Abstract]
Affiliated companies at equity		11,141	10,160
Other Noncurrent Assets [Abstract]
Deferred income taxes		46	70
Price risk management assets		186	284
Other noncurrent assets		1	1
Total Other Noncurrent Assets		233	355
Total Assets		11,594	10,599
Current Liabilities [Abstract]
Short-term debt with affiliates		157	44
Accounts payable with affiliates		2	30
Dividends		273	259
Price risk management liabilities		233	237
Other current liabilities		19	20
Total Current Liabilities		684	590
Long-term Debt [Abstract]
Total Deferred Credits and Other Noncurrent Liabilities		149	110
Equity [Abstract]
Common stock		7	7
Additional paid-in capital		10,305	9,841
Earnings reinvested		3,871	3,829
Accumulated other comprehensive loss		(3,422)	(3,778)
Total Equity		10,761	9,899
Total Liabilities and Equity		$ 11,594	$ 10,599
PPL Corporation Shareowners' Common Equity Additional Information [Abstract]
Common stock par value		$ 0.01	$ 0.01
Common stock shares authorized		1,560,000
Common stock shares issued		693,398	679,731
Common stock shares outstanding		693,398	679,731
L G And E And K U Energy L L C Unconsolidated [Member]
Current Assets
Cash and cash equivalents		$ 0	$ 1	$ 0	$ 0
Accounts Receivable [Abstract]
Accounts receivable		1	0
Accounts receivable from affiliates		8	23
Income Taxes Receivable, Current		1	31
Notes receivable from affiliates		1,035	1,007
Total Current Assets		1,045	1,062
Investments [Abstract]
Affiliated companies at equity		5,209	5,219
Other Noncurrent Assets [Abstract]
Deferred income taxes		263	227
Total Assets		6,517	6,508
Current Liabilities [Abstract]
Notes payable to affiliates		241	179
Accounts payable with affiliates		469	450
Taxes		35	0
Other current liabilities		5	6
Total Current Liabilities		750	635
Long-term Debt [Abstract]
Long-term debt		722	721
Notes payable to affiliates		476	480
Total Long-term Debt		1,198	1,201
Total Deferred Credits and Other Noncurrent Liabilities		6	5
Equity [Abstract]
Members Equity		4,563	4,667
Total Liabilities and Equity		$ 6,517	$ 6,508
[1]	1,560,000 shares authorized; 693,398 and 679,731 shares issued and outstanding at December 31, 2017 and December 31, 2016.

SCHEDULE I - NOTES TO CONDENSED

SCHEDULE I - NOTES TO CONDENSED UNCONSOLIDATED FINANCIAL STATEMENTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Condensed Unconsolidated Financial Statements [Line Items]
2,020	$ 1,278
Aggregate maturities of long-term debt (Details) [Abstract]
2,021	1,150
Principal outstanding	20,282	$ 18,399
LKE Guarantee [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member]
Condensed Unconsolidated Financial Statements [Line Items]
Maximum exposure	$ 201
Term of guarantee (in years)	12 years
Maximum exposure of guarantee related to terminated lease specific to operational, regulatory and environmental issues	$ 200
Maximum exposure of other guarantees expiring related to a terminated lease	$ 100
L G And E And K U Energy L L C Unconsolidated [Member]
Condensed Unconsolidated Financial Statements [Line Items]
Loss Contingency, Settlement Agreement, Terms	11
PPL Corp [Member] | PPL Guarantee [Member] | Financial Guarantee [Member] | Indemnifications issued by PPL Capital Funding [Member]
Condensed Unconsolidated Financial Statements [Line Items]
Maximum exposure	$ 9,700
Expiration date	2,073
L G And E And K U Energy L L C Unconsolidated [Member] | Senior Unsecured Notes [Member]
Condensed Unconsolidated Financial Statements [Line Items]
2,020	$ 475
Aggregate maturities of long-term debt (Details) [Abstract]
2,021	250
L G And E And K U Energy L L C Unconsolidated [Member] | Note Payable [Member] | PPL [Member]
Aggregate maturities of long-term debt (Details) [Abstract]
Principal outstanding	$ 400
Maturity date (in years)	Dec. 31, 2026
L G And E And K U Energy L L C Unconsolidated [Member] | Note Payable [Member] | L G And E And K U Services Company [Member]
Aggregate maturities of long-term debt (Details) [Abstract]
Principal outstanding	$ 76
Maturity date (in years)	Dec. 31, 2019
Stated interest rate	2.10%
L G And E And K U Energy L L C Unconsolidated [Member] | LKE Guarantee [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member]
Condensed Unconsolidated Financial Statements [Line Items]
Term of guarantee (in years)	12
Expiration date minimum	2,021
Maximum exposure of guarantee related to terminated lease specific to operational, regulatory and environmental issues	$ 200
Maximum exposure of other guarantees expiring related to a terminated lease	$ 100
Expiration date maximum	2,023

Quarterly Financial Data (Un105

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended								12 Months Ended
	Nov. 30, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Quarterly Financial Information Disclosure [Line Items]
Operating Revenues		$ 1,926	$ 1,845	$ 1,725	$ 1,951	$ 1,832	$ 1,889	$ 1,785	$ 2,011	$ 7,447		$ 7,517		$ 7,669
Operating income		793	777	702	796	714	786	725	823	3,068		3,048		2,831
Income from continuing operations after income taxes										1,128		1,902		1,603
Loss from Discontinued Operations (net of income taxes)										0		0		(921)
Net income (loss)		$ 78	$ 355	$ 292	$ 403	$ 465	$ 473	$ 483	$ 481	$ 1,128		$ 1,902		$ 682
Income from continuing operations after income taxes available to PPL common shareowners: [Abstract]
Basic (in dollars per share)										$ 1.64		$ 2.80		$ 2.38
Diluted (in dollars per share)										1.64		2.79		2.37
Net income (loss) available to PPL common shareowners: [Abstract]
Basic (in dollars per share)		$ 0.11	$ 0.52	$ 0.43	$ 0.59	$ 0.68	$ 0.70	$ 0.71	$ 0.71	1.64		2.80		1.01
Diluted (in dollars per share)		0.11	0.51	0.43	0.59	0.68	0.69	0.71	0.71	1.64		2.79		1.01
Dividends declared per share of common stock (in dollars per share)	$ 0.395	0.3950	0.3950	0.3950	0.3950	0.38	0.38	0.38	0.38	$ 1.58		$ 1.52		$ 1.50
Price per common share: [Abstract]
High (in dollars per share)		38.37	39.83	40.06	37.70	34.74	37.71	39.68	38.07
Low (in dollars per share)		$ 30.76	$ 37.36	$ 37.11	$ 33.94	$ 32.19	$ 33.63	$ 36.27	$ 32.80
PPL Energy Supply Spinoff [Member]
Quarterly Financial Information Disclosure [Line Items]
Loss from Discontinued Operations (net of income taxes)														$ (921)
Price per common share: [Abstract]
Gain (loss) on disposal group														(879)
PPL Electric Utilities Corp [Member]
Quarterly Financial Information Disclosure [Line Items]
Operating Revenues		$ 575	$ 547	$ 500	$ 573	$ 537	$ 539	$ 495	$ 585	$ 2,195		$ 2,156		2,124
Operating income		197	189	156	159	154	176	154	180	701		664		538
Net income (loss)		$ 111	$ 95	$ 77	$ 79	$ 77	$ 90	$ 79	$ 94	$ 362	[1]	$ 340	[1]	$ 252	[1]
[1]	Net income equals comprehensive income.