Derivative Instruments and Hedging Activities (Offsetting Derivative Instruments and Credit Risk-Related Features) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Offsetting Assets And Liabilities [Line Items]
Cash collateral received eligible for offset - assets	$ 0	$ 0
Cash collateral pledged eligible for offset - liabilities	0	4
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	36
Derivative Net Liability Position Containing Credit Risk Related Contingency Features	35
Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	1	25
Derivative instruments eligible for offset - assets	0	20
Cash collateral received eligible for offset - assets	0	0
Net assets	1	5
Gross liabilities	67	73
Derivative instruments eligible for offset - liabilities	0	62
Cash collateral pledged eligible for offset - liabilities	0	0
Net liabilities	67	11
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	7	7
Derivative instruments eligible for offset - liabilities	0	0
Cash collateral pledged eligible for offset - liabilities	0	0
Net liabilities	7	7
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