Utility Rate Regulation (Regulatory Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Regulatory Assets [Line Items]
Current Regulatory Assets	$ 36	$ 34
Noncurrent Regulatory Assets	1,673	1,504
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	5
Generation formula rate [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	6
Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	12	4
Smart meter rider [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	11	15
Plant outage costs [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	10	3
Other [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	3	1
Noncurrent Regulatory Assets	7	9
Defined benefit plans [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	963	880
Taxes recoverable through future rates [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	3	3
Storm costs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	56	33
Unamortized loss on debt [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	45	54
Interest rate swaps [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	20	26
Terminated interest rate swaps [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	87	92
Accumulated cost of removal of utility plant [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	200	173
AROs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	273	234
Act 129 compliance rider [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	19	0
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	11	16
Noncurrent Regulatory Assets	824	709
PPL Electric Utilities Corp [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	0
PPL Electric Utilities Corp [Member] | Generation formula rate [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	11	15
PPL Electric Utilities Corp [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	0
PPL Electric Utilities Corp [Member] | Other [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	1
Noncurrent Regulatory Assets	0	0
PPL Electric Utilities Corp [Member] | Defined benefit plans [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	558	504
PPL Electric Utilities Corp [Member] | Taxes recoverable through future rates [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	3	3
PPL Electric Utilities Corp [Member] | Storm costs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	22	0
PPL Electric Utilities Corp [Member] | Unamortized loss on debt [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	22	29
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	200	173
PPL Electric Utilities Corp [Member] | AROs [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	19	0
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	25	18
Noncurrent Regulatory Assets	849	795
LG And E And KU Energy LLC [Member] | Generation formula rate [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	6
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	12	4
LG And E And KU Energy LLC [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	10	3
LG And E And KU Energy LLC [Member] | Other [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	3	5
Noncurrent Regulatory Assets	7	9
LG And E And KU Energy LLC [Member] | Defined benefit plans [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	405	376
LG And E And KU Energy LLC [Member] | Storm costs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	34	33
LG And E And KU Energy LLC [Member] | Unamortized loss on debt [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	23	25
LG And E And KU Energy LLC [Member] | Interest rate swaps [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	20	26
LG And E And KU Energy LLC [Member] | Terminated interest rate swaps [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	87	92
LG And E And KU Energy LLC [Member] | AROs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	273	234
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	21	12
Noncurrent Regulatory Assets	431	411
Louisville Gas And Electric Co [Member] | Generation formula rate [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	0
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	12	4
Louisville Gas And Electric Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	7	3
Louisville Gas And Electric Co [Member] | Other [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	2	5
Noncurrent Regulatory Assets	1	2
Louisville Gas And Electric Co [Member] | Defined benefit plans [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	249	234
Louisville Gas And Electric Co [Member] | Storm costs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	20	18
Louisville Gas And Electric Co [Member] | Unamortized loss on debt [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	15	16
Louisville Gas And Electric Co [Member] | Interest rate swaps [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	20	26
Louisville Gas And Electric Co [Member] | Terminated interest rate swaps [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	51	54
Louisville Gas And Electric Co [Member] | AROs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	75	61
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	4	6
Noncurrent Regulatory Assets	418	384
Kentucky Utilities Co [Member] | Generation formula rate [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	6
Kentucky Utilities Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	0	0
Kentucky Utilities Co [Member] | Plant outage costs [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	3	0
Kentucky Utilities Co [Member] | Other [Member]
Regulatory Assets [Line Items]
Current Regulatory Assets	1	0
Noncurrent Regulatory Assets	6	7
Kentucky Utilities Co [Member] | Defined benefit plans [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	156	142
Kentucky Utilities Co [Member] | Storm costs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	14	15
Kentucky Utilities Co [Member] | Unamortized loss on debt [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	8	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	36	38
Kentucky Utilities Co [Member] | AROs [Member]
Regulatory Assets [Line Items]
Noncurrent Regulatory Assets	$ 198	$ 173