Asset Retirement Obligations (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	$ 552
Accretion expense	18
Effect of foreign currency exchange rates	(3)
Obligations settled	(6)
Balance at End of Period	561
Susquehanna Nuclear Station ARO (Numeric) [Abstract]
Susquehanna accrued nuclear decommissioning obligation	329	316
Susquehanna NDT funds	771	712
PPL Energy Supply LLC [Member]
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	375
Accretion expense	14
Changes in estimated cash flow or settlement date	(1)
Obligations settled	(3)
Balance at End of Period	385
Susquehanna Nuclear Station ARO (Numeric) [Abstract]
Susquehanna accrued nuclear decommissioning obligation	329	316
Susquehanna NDT funds	771	712
LG And E And KU Energy LLC [Member]
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	131
Accretion expense	3
Changes in estimated cash flow or settlement date	1
Obligations settled	(3)
Balance at End of Period	132
Louisville Gas And Electric Co [Member]
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	62
Accretion expense	1
Changes in estimated cash flow or settlement date	1
Obligations settled	(3)
Balance at End of Period	61
Kentucky Utilities Co [Member]
Asset Retirement Obligation [Rollforward]
Balance at Beginning of Period	69
Accretion expense	2
Balance at End of Period	$ 71