Utility Rate Regulation - Regulatory Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 90	$ 115
Noncurrent regulatory liabilities	2,543	2,572
Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	23	23
Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	5
Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	14	9
Fuel adjustment clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8	8
TCJA customer refund [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	21	61
Storm Damage Expense Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	7	5
Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8	0
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	648	640
Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	45	51
Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,705	1,756
Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	59	51
Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	66	68
Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	4
Noncurrent regulatory liabilities	20	6
PPL Electric Utilities Corp [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	73	96
Noncurrent regulatory liabilities	582	599
PPL Electric Utilities Corp [Member] | Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	23	23
PPL Electric Utilities Corp [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	14	9
PPL Electric Utilities Corp [Member] | Fuel adjustment clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | TCJA customer refund [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	21	59
PPL Electric Utilities Corp [Member] | Storm Damage Expense Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	7	5
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8	0
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	565	588
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	17	11
PPL Electric Utilities Corp [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
Noncurrent regulatory liabilities	0	0
LG And E And KU Energy LLC [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	17	19
Noncurrent regulatory liabilities	1,961	1,973
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	5
LG And E And KU Energy LLC [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	2	3
LG And E And KU Energy LLC [Member] | Fuel adjustment clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8	8
LG And E And KU Energy LLC [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	648	640
LG And E And KU Energy LLC [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	45	51
LG And E And KU Energy LLC [Member] | Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,140	1,168
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	42	40
LG And E And KU Energy LLC [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	66	68
LG And E And KU Energy LLC [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1	3
Noncurrent regulatory liabilities	20	6
Louisville Gas And Electric Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	5	2
Noncurrent regulatory liabilities	885	883
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	2	1
Louisville Gas And Electric Co [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1	1
Louisville Gas And Electric Co [Member] | Fuel adjustment clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	2	0
Louisville Gas And Electric Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	271	266
Louisville Gas And Electric Co [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	31	35
Louisville Gas And Electric Co [Member] | Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	532	544
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
Louisville Gas And Electric Co [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	33	34
Louisville Gas And Electric Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
Noncurrent regulatory liabilities	18	4
Kentucky Utilities Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	12	17
Noncurrent regulatory liabilities	1,076	1,090
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	4	4
Kentucky Utilities Co [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1	2
Kentucky Utilities Co [Member] | Fuel adjustment clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	8
Kentucky Utilities Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	377	374
Kentucky Utilities Co [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	14	16
Kentucky Utilities Co [Member] | Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	608	624
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	42	40
Kentucky Utilities Co [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	33	34
Kentucky Utilities Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1	3
Noncurrent regulatory liabilities	$ 2	$ 2