Asset Retirement Obligations (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($)
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	$ 347
Accretion	13
Effect of foreign exchange rates	(2)
Changes in estimated timing or cost	(5)
Obligations settled	(67)
Balance at End of Period	286
LG And E And KU Energy LLC [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	296
Accretion	12
Effect of foreign exchange rates	0
Changes in estimated timing or cost	(2)
Obligations settled	(67)
Balance at End of Period	239
Louisville Gas And Electric Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	103
Accretion	4
Effect of foreign exchange rates	0
Changes in estimated timing or cost	(2)
Obligations settled	(22)
Balance at End of Period	83
Kentucky Utilities Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	193
Accretion	8
Effect of foreign exchange rates	0
Changes in estimated timing or cost	0
Obligations settled	(45)
Balance at End of Period	$ 156