Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	$ 125	$ 115	$ 359	$ 373
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	13	9	34	34
Valuation allowance adjustments	7	5	21	17
Impact of lower U.K. income tax rates relative to U.S. income tax rates	(6)	(7)	(20)	(20)
Impact of the U.K. Finance Act on deferred tax balances	(5)	(4)	(8)	(7)
Depreciation and other items not normalized	(2)	(1)	(5)	(4)
Amortization of excess deferred income taxes	(9)	(11)	(30)	(30)
Deferred tax impact of state tax reform	0	0	0	9
Interest benefit on U.K. financing entities	(3)	(4)	(9)	(13)
Kentucky recycling credit, net of federal income tax expense	0	0	(20)	0
Other	(2)	1	6	3
Total increase (decrease)	(7)	(12)	(31)	(11)
Total income taxes	118	103	328	362
Valuation allowance associated with Kentucky recycling credit [Member]
Increase (decrease) due to: [Abstract]
Valuation allowance adjustments	3
PPL Electric Utilities Corp [Member]
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	33	30	94	93
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	13	12	36	35
Depreciation and other items not normalized	(2)	(1)	(5)	(4)
Amortization of excess deferred income taxes	(4)	(5)	(12)	(13)
Other	0	(1)	1	0
Total increase (decrease)	7	5	20	18
Total income taxes	40	35	114	111
LG And E And KU Energy LLC [Member]
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	42	34	98	97
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	8	6	18	17
Valuation allowance adjustments	0	0	3	0
Amortization of investment tax credit	(1)	(1)	(2)	(3)
Deferred tax impact of U.S. tax reform	0	(2)	0	(2)
Amortization of excess deferred income taxes	(5)	(3)	(17)	(14)
Deferred tax impact of state tax reform	0	0	0	9
Kentucky recycling credit, net of federal income tax expense	0	0	(20)	0
Other	(1)	(2)	(2)	(2)
Total increase (decrease)	1	(2)	(20)	5
Total income taxes	43	32	78	102
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	50	50
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	4	3	9	9
Valuation allowance adjustments	0	0	15	0
Amortization of excess deferred income taxes	(2)	(1)	(7)	(6)
Kentucky recycling credit, net of federal income tax expense	0	0	(15)	0
Other	(1)	(2)	(1)	(2)
Total increase (decrease)	1	0	1	1
Total income taxes	22	18	51	51
Kentucky Utilities Co [Member]
Reconciliation of Income Tax Expense [Abstract]
Federal income tax on Income Before Income Taxes at statutory tax rate	25	21	63	60
Increase (decrease) due to: [Abstract]
State income taxes, net of federal income tax benefit	5	3	12	10
Valuation allowance adjustments	0	0	5	0
Amortization of excess deferred income taxes	(3)	(2)	(10)	(8)
Kentucky recycling credit, net of federal income tax expense	0	0	(5)	0
Other	(1)	(1)	(3)	(3)
Total increase (decrease)	1	0	(1)	(1)
Total income taxes	$ 26	$ 21	$ 62	$ 59