Asset Retirement Obligations (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	$ 586
Accretion	20
Effect of foreign currency exchange rates	(7)
Changes in estimated timing or cost	(116)
Obligations settled	(15)
Balance at End of Period	468
LG And E And KU Energy LLC [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	535
Accretion	18
Changes in estimated timing or cost	(116)
Obligations settled	(15)
Balance at End of Period	422
Decrease to the asset retirement obligation due to revisions in the amounts and timing of future expected cash flows related to the closure of CCR impoundments	118
Louisville Gas And Electric Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	175
Accretion	6
Changes in estimated timing or cost	(24)
Obligations settled	(11)
Balance at End of Period	146
Decrease to the asset retirement obligation due to revisions in the amounts and timing of future expected cash flows related to the closure of CCR impoundments	24
Kentucky Utilities Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	360
Accretion	12
Changes in estimated timing or cost	(92)
Obligations settled	(4)
Balance at End of Period	276
Decrease to the asset retirement obligation due to revisions in the amounts and timing of future expected cash flows related to the closure of CCR impoundments	$ 94