Utility Rate Regulation - Regulatory Assets (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Regulatory Assets [Line Items]
Current regulatory assets	$ 121	$ 99
Noncurrent regulatory assets	1,233	1,262
Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	55	46
Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	8	4
Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets	21	17
Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	20	15
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	556	570
Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	7
Noncurrent regulatory assets	14	17
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	29	30
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	18	23
Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	74	75
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	234	240
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	304	300
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	12	10
Noncurrent regulatory assets	4	7
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	47	40
Noncurrent regulatory assets	525	541
PPL Electric Utilities Corp [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets	21	17
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	20	15
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	282	290
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	7
Noncurrent regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	7	8
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 Swaps [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	234	240
PPL Electric Utilities Corp [Member] | Asset Retirement Obligations [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	2	3
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets	74	59
Noncurrent regulatory assets	708	721
LG And E And KU Energy LLC [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	55	46
LG And E And KU Energy LLC [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	8	4
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	274	280
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	14	17
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	22	22
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	18	23
LG And E And KU Energy LLC [Member] | Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	74	75
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	304	300
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	11	9
Noncurrent regulatory assets	2	4
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	36	23
Noncurrent regulatory assets	339	351
Louisville Gas And Electric Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	20	12
Louisville Gas And Electric Co [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	8	4
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	170	174
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	9	11
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	13	13
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	18	23
Louisville Gas And Electric Co [Member] | Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	43	44
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	85	85
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	8	7
Noncurrent regulatory assets	1	1
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	38	36
Noncurrent regulatory assets	369	370
Kentucky Utilities Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	35	34
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	104	106
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	5	6
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 Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	31	31
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	219	215
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	2
Noncurrent regulatory assets	$ 1	$ 3