Utility Rate Regulation (Regulatory Assets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Regulatory Assets [Line Items]
Current regulatory assets	$ 32	$ 33
Noncurrent regulatory assets	1,245	1,246
Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	19	10
Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	10	2
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	503	509
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	307	306
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	141	147
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	82	85
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	48	44
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	101	98
Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1	8
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	51	44
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2	6
Noncurrent regulatory assets	12	13
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1	6
Noncurrent regulatory assets	770	772
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	255	257
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	307	306
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	51	53
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	54	57
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	101	98
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1	6
Noncurrent regulatory assets	2	1
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets	31	27
Noncurrent regulatory assets	475	474
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	19	10
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	10	2
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	248	252
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	90	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	48	44
LG And E And KU Energy LLC [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1	8
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	51	44
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1
Noncurrent regulatory assets	10	12
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	22	17
Noncurrent regulatory assets	303	303
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	19	10
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2	2
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	161	164
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	49	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	48	44
Louisville Gas And Electric Co [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1	3
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	23	21
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		2
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	4	5
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	9	10
Noncurrent regulatory assets	172	171
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	8
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	87	88
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	41	43
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	10	10
Kentucky Utilities Co [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets		5
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	28	23
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		5
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	1
Noncurrent regulatory assets	$ 6	$ 7