Utility Rate Regulation (Regulatory Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets [Line Items]
Current regulatory assets	[1]	$ 48	$ 37
Noncurrent regulatory assets		1,733	1,562
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		24	5
Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	15
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		10	6
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		809	720
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		326	316
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		93	124
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		68	77
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		141	122
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		137	114
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		143	79
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		13	11
Noncurrent regulatory assets		16	10
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets		13	12
Noncurrent regulatory assets		1,006	897
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		10	6
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		469	372
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		326	316
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		30	46
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		42	49
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		137	114
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		3	6
Noncurrent regulatory assets		2	0
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets		35	25
Noncurrent regulatory assets		727	665
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		24	5
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	15
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		340	348
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		63	78
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		26	28
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		141	122
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		143	79
LG And E And KU Energy LLC [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		6	0
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	4
LG And E And KU Energy LLC [Member] | Gas Line Tracker [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	0
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		9	1
Noncurrent regulatory assets		8	10
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		16	21
Noncurrent regulatory assets		424	397
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		13	4
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	15
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		35	43
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		17	18
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		98	89
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		57	28
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	2
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	0
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1	0
Noncurrent regulatory assets		2	4
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		19	4
Noncurrent regulatory assets		303	268
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		11	1
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		125	133
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		28	35
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		9	10
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		43	33
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		86	51
Kentucky Utilities Co [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		6	0
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	2
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		8	1
Noncurrent regulatory assets		$ 6	$ 6

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