Utility Rate Regulation (Regulatory Assets) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Regulatory Assets [Line Items]
Current regulatory assets	$ 28	$ 33
Noncurrent regulatory assets	1,253	1,246
Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	20	10
Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	2
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	486	509
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	313	306
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	130	147
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	79	85
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	54	44
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	111	98
Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	8
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	72	44
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	7
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5	6
Noncurrent regulatory assets	8	13
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	6
Noncurrent regulatory assets	772	772
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	250	257
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	313	306
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	47	53
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	51	57
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	111	98
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	6
Noncurrent regulatory assets	0	1
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets	25	27
Noncurrent regulatory assets	481	474
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	20	10
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	2
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	236	252
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	83	94
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	28	28
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	54	44
LG And E And KU Energy LLC [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	8
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	72	44
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	7
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2	0
Noncurrent regulatory assets	8	12
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	23	17
Noncurrent regulatory assets	305	303
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	20	10
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] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	159	164
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	45	51
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	18	18
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	52	44
Louisville Gas And Electric Co [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	3
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	27	21
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3	2
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	0
Noncurrent regulatory assets	4	5
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2	10
Noncurrent regulatory assets	176	171
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	77	88
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	38	43
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	10	10
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	2	0
Kentucky Utilities Co [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	5
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	45	23
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	0	5
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2	0
Noncurrent regulatory assets	$ 4	$ 7