v3.25.2
Derivative Instruments and Hedging Activities - Offsetting Derivative Instruments and Credit Risk-Related Features (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Assets [Abstract]    
Cash collateral received - eligible for offset $ 0 $ 0
Liabilities [Abstract]    
Cash collateral pledged - eligible for offset 0 0
Credit Risk-Related Contingent Features [Abstract]    
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade 0  
Treasury Derivatives [Member]    
Assets [Abstract]    
Gross 12 9
Derivative instruments - eligible for offset 3 5
Cash collateral received - eligible for offset 0 0
Net 9 4
Liabilities [Abstract]    
Gross 13 16
Derivative instruments - eligible for offset 3 5
Cash collateral pledged - eligible for offset 0 0
Net 10 11
Louisville Gas And Electric Co [Member]    
Assets [Abstract]    
Cash collateral received - eligible for offset 0 0
Liabilities [Abstract]    
Cash collateral pledged - eligible for offset 0 0
Louisville Gas And Electric Co [Member] | Treasury Derivatives [Member]    
Assets [Abstract]    
Gross 0 0
Derivative instruments - eligible for offset 0 0
Cash collateral received - eligible for offset 0 0
Net 0 0
Liabilities [Abstract]    
Gross 5 3
Derivative instruments - eligible for offset 0 0
Cash collateral pledged - eligible for offset 0 0
Net $ 5 $ 3