Derivative Instruments and Hedging Activities (Offsetting Derivative Instruments and Credit Risk-Related Features) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Offsetting Assets And Liabilities [Line Items]
Cash collateral received eligible for offset - assets	$ 0	$ 0
Cash collateral pledged eligible for offset - liabilities	0	0
Credit Risk-Related Contingent Features [Abstract]
Derivative Net Liability Position Containing Credit Risk Related Contingency Features	0
Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	0	146
Derivative instruments eligible for offset - assets	0	34
Cash collateral received eligible for offset - assets	0	0
Net assets	0	112
Gross liabilities	18	160
Derivative instruments eligible for offset - liabilities	0	34
Cash collateral pledged eligible for offset - liabilities	0	0
Net liabilities	18	126
Louisville Gas And Electric Co [Member]
Offsetting Assets And Liabilities [Line Items]
Cash collateral received eligible for offset - assets	0	0
Cash collateral pledged eligible for offset - liabilities	0	0
Louisville Gas And Electric Co [Member] | Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	0	0
Derivative instruments eligible for offset - assets	0	0
Cash collateral received eligible for offset - assets	0	0
Net assets	0	0
Gross liabilities	18	23
Derivative instruments eligible for offset - liabilities	0	0
Cash collateral pledged eligible for offset - liabilities	0	0
Net liabilities	18	23
Kentucky Utilities Co [Member]
Offsetting Assets And Liabilities [Line Items]
Cash collateral received eligible for offset - assets	0	0
Cash collateral pledged eligible for offset - liabilities	$ 0	$ 0