Asset Retirement Obligations (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	$ 347
Accretion	4
Effect of foreign exchange rates	2
Changes in estimated timing or cost	8
Obligations settled	(21)
Balance at End of Period	340
LG And E And KU Energy LLC [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	296
Accretion	4
Effect of foreign exchange rates	0
Changes in estimated timing or cost	8
Obligations settled	(21)
Balance at End of Period	287
Louisville Gas And Electric Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	103
Accretion	2
Effect of foreign exchange rates	0
Changes in estimated timing or cost	8
Obligations settled	(4)
Balance at End of Period	109
Kentucky Utilities Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	193
Accretion	2
Effect of foreign exchange rates	0
Changes in estimated timing or cost	0
Obligations settled	(17)
Balance at End of Period	$ 178