Income and Other Taxes (Income Tax Expense and Reconciliation of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense (Benefit)
Current - Federal	$ (9)	$ (10)	$ (19)
Current - State	24	19	17
Current - Foreign	85	91	104
Total Current Expense	100	100	102
Deferred - Federal	123	139	203
Deferred - State	94	76	100
Deferred - Foreign	215	123	107
Total Deferred Expense (Benefit), excluding operating loss carry forwards	432	338	410
Amortization of investment tax credit	(3)	(3)	(3)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	6	7	(20)
Deferred - State	(33)	(33)	(31)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	(27)	(26)	(51)
Total income tax from continuing operations	502	409	458
Income tax expense [Abstract]
Total income tax expense - Federal	117	133	161
Total income tax expense - State	85	62	86
Total income tax expense - Foreign	300	214	211
Total income tax from continuing operations	502	409	458
Income Tax Expense (Benefit) Excluded From Income Taxes [Abstract]
Other comprehensive income	(19)	(93)	(6)
Total income tax expense (benefits) excluded from incomes taxes from continuing operations	(19)	(93)	(6)
Reconciliation of Income Tax Expense
Federal income tax on Income Before Income Taxes at statutory tax rate	414	453	480
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	48	45	40
Valuation allowance adjustments	26	22	21
Impact of lower U.K. income tax rates	(26)	(25)	(25)
U.S. income tax on foreign earnings - net of foreign tax credit	11	2	3
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(9)	1	0
Impact of the United Kingdom Finance Acts on deferred tax balances	101	(14)	(13)
Depreciation and other items not normalized	(5)	(10)	(11)
Amortization of excess deferred federal and state income taxes	(43)	(40)	(37)
Interest benefit on United Kingdom financing entities	(12)	(12)	(17)
Deferred tax impact of Kentucky tax reform	0	0	9
Kentucky recycling credit, net of federal income tax expense	0	(18)	0
Other	(3)	5	8
Total increase (decrease)	88	(44)	(22)
Total income tax from continuing operations	$ 502	$ 409	$ 458
Effective income tax rate	25.50%	19.00%	20.00%
Expense related to increased Pennsylvania net operating loss carryforwards expected to be unutilized	$ 24	$ 25	$ 24
Taxes, other than income
State gross receipts	100	107	103
Foreign property	127	127	134
Domestic property and other	80	79	75
Total	307	313	312
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, U.K. Finance Act 2020, Amount	106
Foreign Tax Authority [Member]
Income Tax Expense (Benefit)
Deferred - Foreign	106
PPL Electric Utilities Corp [Member]
Income Tax Expense (Benefit)
Current - Federal	61	44	2
Current - State	23	15	9
Total Current Expense	84	59	11
Deferred - Federal	45	51	96
Deferred - State	38	39	37
Total Deferred Expense (Benefit), excluding operating loss carry forwards	83	90	133
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	0	0	(8)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	0	0	(8)
Total income tax from continuing operations	167	149	136
Income tax expense [Abstract]
Total income tax expense - Federal	106	95	90
Total income tax expense - State	61	54	46
Total income tax from continuing operations	167	149	136
Reconciliation of Income Tax Expense
Federal income tax on Income Before Income Taxes at statutory tax rate	139	127	119
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	52	47	43
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(4)	1	0
Depreciation and other items not normalized	(5)	(10)	(11)
Amortization of excess deferred federal and state income taxes	(16)	(18)	(17)
Other	1	2	2
Total increase (decrease)	28	22	17
Total income tax from continuing operations	$ 167	$ 149	$ 136
Effective income tax rate	25.20%	24.60%	24.00%
Taxes, other than income
State gross receipts	$ 100	$ 107	$ 103
Domestic property and other	7	5	6
Total	107	112	109
LG And E And KU Energy LLC [Member]
Income Tax Expense (Benefit)
Current - Federal	41	20	31
Current - State	1	0	4
Total Current Expense	42	20	35
Deferred - Federal	43	81	65
Deferred - State	24	5	34
Total Deferred Expense (Benefit), excluding operating loss carry forwards	67	86	99
Amortization of investment tax credit	(3)	(3)	(3)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Deferred - Federal	0	0	(2)
Total Tax Expense (Benefit) of Operating Loss Carryforwards	0	0	(2)
Total income tax from continuing operations	106	103	129
Income tax expense [Abstract]
Total income tax expense - Federal	81	98	91
Total income tax expense - State	25	5	38
Total income tax from continuing operations	106	103	129
Income Tax Expense (Benefit) Excluded From Income Taxes [Abstract]
Other comprehensive income	2	(1)	5
Reconciliation of Income Tax Expense
Federal income tax on Income Before Income Taxes at statutory tax rate	117	120	121
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	22	23	22
Valuation allowance adjustments	(28)	(23)	(20)
Amortization of investment tax credit	(3)	(3)	(3)
Deferred tax impact of Kentucky tax reform	0	0	9
Kentucky recycling credit, net of federal income tax expense	0	(18)	0
Other	(2)	4	0
Total increase (decrease)	(11)	(17)	8
Total income tax from continuing operations	$ 106	$ 103	$ 129
Effective income tax rate	19.10%	18.00%	22.50%
Taxes, other than income
Domestic property and other	$ 77	$ 74	$ 70
Total	77	74	70
Louisville Gas And Electric Co [Member]
Income Tax Expense (Benefit)
Current - Federal	53	4	0
Current - State	7	4	4
Total Current Expense	60	8	4
Deferred - Federal	(4)	46	51
Deferred - State	7	10	10
Total Deferred Expense (Benefit), excluding operating loss carry forwards	3	56	61
Amortization of investment tax credit	(1)	(1)	(1)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	62	63	64
Income tax expense [Abstract]
Total income tax expense - Federal	48	49	50
Total income tax expense - State	14	14	14
Total income tax from continuing operations	62	63	64
Reconciliation of Income Tax Expense
Federal income tax on Income Before Income Taxes at statutory tax rate	64	62	62
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	12	12	11
Valuation allowance adjustments	0	14	0
Amortization of excess deferred federal and state income taxes	(11)	(10)	(8)
Kentucky recycling credit, net of federal income tax expense	0	(14)	0
Other	(3)	(1)	(1)
Total increase (decrease)	(2)	1	2
Total income tax from continuing operations	$ 62	$ 63	$ 64
Effective income tax rate	20.30%	21.40%	21.50%
Taxes, other than income
Domestic property and other	$ 40	$ 39	$ 36
Total	40	39	36
Kentucky Utilities Co [Member]
Income Tax Expense (Benefit)
Current - Federal	40	35	22
Current - State	3	5	6
Total Current Expense	43	40	28
Deferred - Federal	11	28	40
Deferred - State	11	13	10
Total Deferred Expense (Benefit), excluding operating loss carry forwards	22	41	50
Amortization of investment tax credit	(2)	(2)	(2)
Tax expense (benefit) of operating loss carryforwards [Abstract]
Total income tax from continuing operations	63	79	76
Income tax expense [Abstract]
Total income tax expense - Federal	49	61	60
Total income tax expense - State	14	18	16
Total income tax from continuing operations	63	79	76
Reconciliation of Income Tax Expense
Federal income tax on Income Before Income Taxes at statutory tax rate	72	78	76
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	14	15	13
Valuation allowance adjustments	0	4	0
Amortization of investment tax credit	(2)	(2)	(2)
Amortization of excess deferred federal and state income taxes	(17)	(13)	(12)
Kentucky recycling credit, net of federal income tax expense	0	(4)	0
Other	(4)	1	1
Total increase (decrease)	(9)	1	0
Total income tax from continuing operations	$ 63	$ 79	$ 76
Effective income tax rate	18.40%	21.20%	21.00%
Taxes, other than income
Domestic property and other	$ 37	$ 35	$ 34
Total	$ 37	$ 35	$ 34