Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	$ 55	$ 59	$ 70	$ 155
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	17	15	12	39
Valuation allowance adjustments	5	7	39	19
Amortization of excess deferred income taxes	(18)	(11)	(38)	(34)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(4)	(9)	(4)	(9)
Other	(4)	0	(7)	(5)
Total increase (decrease)	(4)	106	385	111
Total income tax expense (benefit)	51	165	455	266
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	0	104	383	101
Deferred Tax Assets, Valuation Allowance	31		31
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, U.K. Finance Act 2021, Amount		102	383
Domestic Tax Authority [Member]
Increase (decrease) due to: [Abstract]
Net Operating Loss Carryforwards, Used During the Period			1,111
Deferred Tax Assets, Operating Loss Carryforwards, Adjustment, Domestic	506		506
Domestic Tax Authority [Member] | Investment Tax Credit Carryforward [Member]
Increase (decrease) due to: [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Used during the period			272
PPL Electric Utilities Corp [Member]
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	36	37	95	104
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	13	14	36	39
Depreciation and other items not normalized	0	0	(4)	(4)
Amortization of excess deferred income taxes	(5)	(4)	(11)	(12)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	0	(4)	0	(4)
Other	1	1	0	2
Total increase (decrease)	9	7	21	21
Total income tax expense (benefit)	45	44	116	125
Louisville Gas And Electric Co [Member]
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	21	18	53	50
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	4	3	10	9
Amortization of excess deferred income taxes	(7)	(3)	(13)	(8)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	0	(2)	0	(2)
Other	(1)	0	(2)	(2)
Total increase (decrease)	(4)	(2)	(5)	(3)
Total income tax expense (benefit)	17	16	48	47
Kentucky Utilities Co [Member]
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	26	22	63	56
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	5	4	12	11
Amortization of excess deferred income taxes	(6)	(4)	(14)	(12)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(1)	(3)	(1)	(3)
Other	(1)	0	(3)	(2)
Total increase (decrease)	(3)	(3)	(6)	(6)
Total income tax expense (benefit)	$ 23	$ 19	$ 57	$ 50