v3.25.2
Fair Value of Financial Assets and Liabilities - Consideration of Credit Risk and Concentrations (Details) - Credit Concentration Risk
$ in Millions
Jun. 30, 2025
USD ($)
Counterparty
Derivative [Line Items]  
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure 10
Municipal or Cooperative Entities or Other Utilities [Member]  
Derivative [Line Items]  
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure 6
External Credit Rating, Investment Grade [Member]  
Derivative [Line Items]  
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure 3
Wholesale, trading and non-trading commodity credit exposure for the most significant counterparties | $ $ 4
Percentage of wholesale, trading and non-trading commodity credit exposure for the most significant counterparties (in hundredths) 10.00%
External Credit Rating, Non Investment Grade [Member]  
Derivative [Line Items]  
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure 0
Internal Investment Grade  
Derivative [Line Items]  
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure 7
Wholesale, trading and non-trading commodity credit exposure for the most significant counterparties | $ $ 31
Percentage of wholesale, trading and non-trading commodity credit exposure for the most significant counterparties (in hundredths) 71.00%