Utility Rate Regulation - Regulatory Assets (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Regulatory Assets [Line Items]
Current regulatory assets	$ 69	$ 99
Noncurrent regulatory assets	1,281	1,262
Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	46
Noncurrent regulatory assets	57	0
Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	11	4
Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets	20	17
Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	21	15
Gas line tracker [Member]
Regulatory Assets [Line Items]
Current regulatory assets	7	4
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	550	570
Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	7
Noncurrent regulatory assets	12	17
Generation formula rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	2
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	26	30
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	20	23
Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	73	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	307	300
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	4
Noncurrent regulatory assets	2	7
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	45	40
Noncurrent regulatory assets	522	541
PPL Electric Utilities Corp [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Noncurrent regulatory assets	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	20	17
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	21	15
PPL Electric Utilities Corp [Member] | Gas line tracker [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	283	290
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	7
Noncurrent regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Generation formula rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	5	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	0	1
Noncurrent regulatory assets	0	3
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	21	23
Noncurrent regulatory assets	354	351
Louisville Gas And Electric Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	12
Noncurrent regulatory assets	16	0
Louisville Gas And Electric Co [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	11	4
Louisville Gas And Electric Co [Member] | Gas line tracker [Member]
Regulatory Assets [Line Items]
Current regulatory assets	7	4
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	167	174
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	8	11
Louisville Gas And Electric Co [Member] | Generation formula rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
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	20	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	86	85
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	3
Noncurrent regulatory assets	1	1
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	36
Noncurrent regulatory assets	405	370
Kentucky Utilities Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	34
Noncurrent regulatory assets	41	0
Kentucky Utilities Co [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Kentucky Utilities Co [Member] | Gas line tracker [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	100	106
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	4	6
Kentucky Utilities Co [Member] | Generation formula rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	2
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	8	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	30	31
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	221	215
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Noncurrent regulatory assets	$ 1	$ 3