Utility Rate Regulation - Regulatory Assets (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Regulatory Assets [Line Items]
Current regulatory assets	$ 75	$ 67
Noncurrent regulatory assets	1,477	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	5	8
Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets	15	13
Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	10
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	788	800
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	34	39
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	37	41
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	29	22
Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	80	81
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	222	220
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	282	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	4
Noncurrent regulatory assets	5	4
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	23	26
Noncurrent regulatory assets	710	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	15	13
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	3
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	10
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	460	467
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	12	15
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	15	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	222	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	52	41
Noncurrent regulatory assets	767	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	5	8
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	328	333
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	22	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	29	22
LG And E And KU Energy LLC [Member] | Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	80	81
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	282	279
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	1
Noncurrent regulatory assets	4	4
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	26	25
Noncurrent regulatory assets	383	380
Louisville Gas And Electric Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	18	16
Louisville Gas And Electric Co [Member] | Gas supply clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	8
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	202	206
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	14	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	29	22
Louisville Gas And Electric Co [Member] | Terminated Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	47	47
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	77	76
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	1
Noncurrent regulatory assets	1	1
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	26	16
Noncurrent regulatory assets	384	386
Kentucky Utilities Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets	26	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	126	127
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	8	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	33	34
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	205	203
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Noncurrent regulatory assets	$ 3	$ 3