Utility Rate Regulation - Regulatory Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 60	$ 122
Noncurrent regulatory liabilities	2,685	2,714
Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	20	33
Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	5	16
Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	14	27
TCJA customer refund [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	7	20
Noncurrent regulatory liabilities	42	41
Storm Damage Expense Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	5
Generation Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	7
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	670	674
Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	55	59
Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,791	1,826
Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	50	37
Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	70	72
Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	11	14
Noncurrent regulatory liabilities	7	5
PPL Electric Utilities Corp [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	43	74
Noncurrent regulatory liabilities	661	675
PPL Electric Utilities Corp [Member] | Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	20	33
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	27
PPL Electric Utilities Corp [Member] | TCJA customer refund [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	3
Noncurrent regulatory liabilities	42	41
PPL Electric Utilities Corp [Member] | Storm Damage Expense Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	5
PPL Electric Utilities Corp [Member] | Generation Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	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	610	629
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	9	5
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	6
Noncurrent regulatory liabilities	0	0
LG And E And KU Energy LLC [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	17	48
Noncurrent regulatory liabilities	2,024	2,039
LG And E And KU Energy LLC [Member] | Deferred Fuel Costs [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	0
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	5	16
LG And E And KU Energy LLC [Member] | TCJA customer refund [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1	17
LG And E And KU Energy LLC [Member] | Generation Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	7
LG And E And KU Energy LLC [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	670	674
LG And E And KU Energy LLC [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	55	59
LG And E And KU Energy LLC [Member] | Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,181	1,197
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	41	32
LG And E And KU Energy LLC [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	70	72
LG And E And KU Energy LLC [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	5	8
Noncurrent regulatory liabilities	7	5
Louisville Gas And Electric Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	4	17
Noncurrent regulatory liabilities	902	915
Louisville Gas And Electric Co [Member] | Deferred Fuel Costs [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	2	6
Louisville Gas And Electric Co [Member] | TCJA customer refund [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	7
Louisville Gas And Electric Co [Member] | Generation Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
Louisville Gas And Electric Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	274	279
Louisville Gas And Electric Co [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	38	41
Louisville Gas And Electric Co [Member] | Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	551	557
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	35	36
Louisville Gas And Electric Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	2	4
Noncurrent regulatory liabilities	4	2
Kentucky Utilities Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	13	31
Noncurrent regulatory liabilities	1,122	1,124
Kentucky Utilities Co [Member] | Deferred Fuel Costs [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	0
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	10
Kentucky Utilities Co [Member] | TCJA customer refund [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1	10
Kentucky Utilities Co [Member] | Generation Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	7
Kentucky Utilities Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	396	395
Kentucky Utilities Co [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	17	18
Kentucky Utilities Co [Member] | Net deferred taxes [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	630	640
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	41	32
Kentucky Utilities Co [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	35	36
Kentucky Utilities Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	4
Noncurrent regulatory liabilities	$ 3	$ 3