v3.25.2
Fair Value of Financial Assets and Liabilities - Fair Value Inputs Assets Quantitative Information (Details) - Level 3
$ in Millions
Jun. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Cash collateral received $ 284 $ 136
Economic Hedges    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Mark-to-market derivatives—Economic hedges $ (147) $ (137)
Economic Hedges | Minimum | Discounted Cash Flow    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Forward power price 5.24 2.57
Forward gas price 1.42 2.09
Economic Hedges | Minimum | Option Model    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Volatility percentage 0.12 0.23
Economic Hedges | Maximum | Discounted Cash Flow    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Forward power price 142 140
Forward gas price 14 15
Economic Hedges | Maximum | Option Model    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Volatility percentage 1.31 1.41
Economic Hedges | Average | Discounted Cash Flow    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Forward power price 52 49
Forward gas price 3.98 3.68
Economic Hedges | Average | Option Model    
Fair Value Measurement Inputs and Valuation Techniques [Abstract]    
Volatility percentage 0.62 0.57