Utility Rate Regulation - Regulatory Assets (Details) - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015
Regulatory Assets [Line Items]
Current regulatory assets	[1]	$ 34	$ 48
Noncurrent regulatory assets		1,762	1,733
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	24
Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		13	7
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		10	10
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		800	809
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		331	326
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		79	93
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		66	68
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		148	141
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		139	137
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		187	143
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		5	7
Noncurrent regulatory assets		12	16
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	[1]	12	13
Noncurrent regulatory assets		995	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] | Generation Formula Rate [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		10	10
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		460	469
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		331	326
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		23	30
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		41	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		139	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		2	3
Noncurrent regulatory assets		1	2
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets		22	35
Noncurrent regulatory assets		767	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] | Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		13	7
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		340	340
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		56	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		148	141
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		187	143
LG And E And KU Energy LLC [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		5	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		6	8
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		8	16
Noncurrent regulatory assets		440	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] | Generation Formula Rate [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		215	215
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		31	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		106	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		2	3
Noncurrent regulatory assets		2	2
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		14	19
Noncurrent regulatory assets		327	303
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	11
Kentucky Utilities Co [Member] | Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		13	7
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		125	125
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		25	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		42	43
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		117	86
Kentucky Utilities Co [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		5	6
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	1
Noncurrent regulatory assets		$ 4	$ 6

[1] These amounts are included in "Other current assets" on the Balance Sheets.