Utility Rate Regulation (Regulatory Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Regulatory Assets [Line Items]
Current regulatory assets	[1]	$ 39	$ 48
Noncurrent regulatory assets		1,918	1,733
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	24
Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets		11	7
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7	10
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		947	809
Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	2
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		340	326
Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets		5	0
Noncurrent regulatory assets		57	93
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		61	68
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		129	141
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		159	137
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		211	143
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		4	5
Noncurrent regulatory assets		14	16
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets		19	13
Noncurrent regulatory assets		1,094	1,006
PPL Electric Utilities Corp [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	0
PPL Electric Utilities Corp [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	0
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7	10
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		549	469
PPL Electric Utilities Corp [Member] | Smart Meter Rider [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	2
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		340	326
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Current regulatory assets		5	0
Noncurrent regulatory assets		9	30
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		36	42
PPL Electric Utilities Corp [Member] | 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		159	137
PPL Electric Utilities Corp [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		0	0
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	1
Noncurrent regulatory assets		1	2
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets		20	35
Noncurrent regulatory assets		824	727
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	24
LG And E And KU Energy LLC [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets		11	7
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		398	340
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		48	63
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		25	26
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		129	141
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		211	143
LG And E And KU Energy LLC [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		4	6
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		3	4
Noncurrent regulatory assets		9	8
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		9	16
Noncurrent regulatory assets		450	424
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	13
Louisville Gas And Electric Co [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	0
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		246	215
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		26	35
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		16	17
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		88	98
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		70	57
Louisville Gas And Electric Co [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		0	0
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		3	3
Noncurrent regulatory assets		4	2
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		11	19
Noncurrent regulatory assets		374	303
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	11
Kentucky Utilities Co [Member] | Municipal Generation True-up [Member]
Regulatory Assets [Line Items]
Current regulatory assets		11	7
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		152	125
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		22	28
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		41	43
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		141	86
Kentucky Utilities Co [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		4	6
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	1
Noncurrent regulatory assets		$ 5	$ 6

[1] For PPL, these amounts are included in "Other current assets" on the Balance Sheets.