Utility Rate Regulation - Regulatory Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Regulatory Assets [Line Items]
Current regulatory assets	$ 82	$ 67
Noncurrent regulatory assets	1,450	1,492
Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	44	32
Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	8
Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets	17	13
Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	9	3
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2	10
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	750	800
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	27	39
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	33	41
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	26	22
Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	77	81
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	237	220
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	297	279
Act 129 Compliance Rider [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	0	6
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6	1
Noncurrent regulatory assets	3	4
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	28	26
Noncurrent regulatory assets	708	726
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	17	13
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	9	3
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2	10
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	450	467
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	9	15
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	11	18
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	237	220
PPL Electric Utilities Corp [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	0	0
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	0	6
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Noncurrent regulatory assets	1	0
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets	54	41
Noncurrent regulatory assets	742	766
LG And E And KU Energy LLC [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	44	32
LG And E And KU Energy LLC [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	8
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	300	333
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	18	24
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	22	23
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	26	22
LG And E And KU Energy LLC [Member] | Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	77	81
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	297	279
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6	1
Noncurrent regulatory assets	2	4
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	23	25
Noncurrent regulatory assets	360	380
Louisville Gas And Electric Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	14	16
Louisville Gas And Electric Co [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	4	8
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	179	206
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	11	14
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	13	14
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	26	22
Louisville Gas And Electric Co [Member] | Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	45	47
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	85	76
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	1
Noncurrent regulatory assets	1	1
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	31	16
Noncurrent regulatory assets	382	386
Kentucky Utilities Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	30	16
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	121	127
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	7	10
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	32	34
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	212	203
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1	0
Noncurrent regulatory assets	$ 1	$ 3