Asset Retirement Obligations (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($)
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	$ 282
Accretion	13
Changes in estimated timing or cost	35
Asset Retirement Obligation, Foreign Currency Translation Gain (Loss)	1
Obligations settled	(64)
Balance at End of Period	267
LG And E And KU Energy LLC [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	215
Accretion	12
Changes in estimated timing or cost	44
Asset Retirement Obligation, Foreign Currency Translation Gain (Loss)	0
Obligations settled	(64)
Balance at End of Period	207
Louisville Gas And Electric Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	73
Accretion	4
Changes in estimated timing or cost	16
Asset Retirement Obligation, Foreign Currency Translation Gain (Loss)	0
Obligations settled	(16)
Balance at End of Period	77
Kentucky Utilities Co [Member]
Asset Retirement Obligation [Roll Forward]
Balance at Beginning of Period	142
Accretion	8
Changes in estimated timing or cost	28
Asset Retirement Obligation, Foreign Currency Translation Gain (Loss)	0
Obligations settled	(48)
Balance at End of Period	$ 130