v3.26.1
Accounting for Derivative Instruments and Hedging Activities - Net Notional Volume Buy/Sell of Open Derivative Transactions (Details) - Long
certificate in Millions, T in Millions, MWh in Millions, MMBTU in Millions, $ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2026
USD ($)
MMBTU
MWh
certificate
T
Dec. 31, 2025
USD ($)
MWh
MMBTU
certificate
T
Emissions    
Volumetric Underlying Derivative Transactions    
Derivative, nonmonetary notional amount, mass (ton) | T 8 2
Renewable Energy Certificates    
Volumetric Underlying Derivative Transactions    
Derivative, non-monetary notional amount (in shares) | certificate 13 13
Coal    
Volumetric Underlying Derivative Transactions    
Derivative, nonmonetary notional amount, mass (ton) | T 5 8
Natural Gas    
Volumetric Underlying Derivative Transactions    
Derivative, nonmonetary notional amount, energy measure (MMBtu/MW/Day) | MMBTU 1,413 907
Power    
Volumetric Underlying Derivative Transactions    
Derivative, nonmonetary notional amount, energy measure (MMBtu/MW/Day) | MWh 34 103
Interest    
Volumetric Underlying Derivative Transactions    
Derivative, notional amount $ 700 $ 700
Foreign Exchange    
Volumetric Underlying Derivative Transactions    
Derivative, notional amount 424 437
Consumer Financing Program    
Volumetric Underlying Derivative Transactions    
Derivative, notional amount $ 1,293 $ 1,354