Utility Rate Regulation (Regulatory Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Regulatory Liabilities [Line Items]
Current regulatory liabilities	$ 122	$ 95
Noncurrent regulatory liabilities	2,714	2,704
Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	33	34
Transmission Service Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	9
Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	16	1
Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	27	26
Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	9
TCJA surcredit [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	20	0
Noncurrent regulatory liabilities	41	0
Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	5	8
Accumulated cost of removal of utility plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	674	677
Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	59	68
Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,826	1,853
Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	37	27
Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	72	74
Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	15	8
Noncurrent regulatory liabilities	5	5
PPL Electric Utilities Corp [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	74	86
Noncurrent regulatory liabilities	675	668
PPL Electric Utilities Corp [Member] | Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	33	34
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	9
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	27	26
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	9
PPL Electric Utilities Corp [Member] | TCJA surcredit [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3	0
Noncurrent regulatory liabilities	41
PPL Electric Utilities Corp [Member] | Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	5	8
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 Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	0	0
PPL Electric Utilities Corp [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	629	668
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	5	0
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	48	9
Noncurrent regulatory liabilities	2,039	2,036
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	16	1
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	3
LG And E And KU Energy LLC [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	2	3
LG And E And KU Energy LLC [Member] | TCJA surcredit [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	17	0
LG And E And KU Energy LLC [Member] | Generation formula rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	7	0
LG And E And KU Energy LLC [Member] | Accumulated cost of removal of utility plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	674	677
LG And E And KU Energy LLC [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	59	68
LG And E And KU Energy LLC [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	1,197	1,185
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	32	27
LG And E And KU Energy LLC [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	72	74
LG And E And KU Energy LLC [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	2
Noncurrent regulatory liabilities	5	5
Louisville Gas And Electric Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	17	3
Noncurrent regulatory liabilities	915	919
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6	0
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	0
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	2	3
Louisville Gas And Electric Co [Member] | TCJA surcredit [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	7	0
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	279	282
Louisville Gas And Electric Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	41	47
Louisville Gas And Electric Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	557	552
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	36	37
Louisville Gas And Electric Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	2	0
Noncurrent regulatory liabilities	2	1
Kentucky Utilities Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	31	6
Noncurrent regulatory liabilities	1,124	1,117
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	10	1
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	0	3
Kentucky Utilities Co [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Kentucky Utilities Co [Member] | TCJA surcredit [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	10	0
Kentucky Utilities Co [Member] | Generation formula rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	7	0
Kentucky Utilities Co [Member] | Accumulated cost of removal of utility plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	395	395
Kentucky Utilities Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	18	21
Kentucky Utilities Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	640	633
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	32	27
Kentucky Utilities Co [Member] | Terminated interest rate swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	36	37
Kentucky Utilities Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	4	2
Noncurrent regulatory liabilities	$ 3	$ 4