v3.25.2
Borrowings and Other Financing Instruments - Borrowings and Other Financing Instruments, Long-Term Borrowings and Other Financing Instruments (Details)
$ in Millions
6 Months Ended
Jun. 30, 2025
USD ($)
Debt Instrument [Line Items]  
Term of letters of credit (in years) 1 year
Bonds [Member] | Series Due May 15, 2034  
Debt Instrument [Line Items]  
Debt Instrument, Face Amount $ 400
Debt Instrument, Interest Rate, Stated Percentage 5.35%
Bonds [Member] | Series Due May 15, 2055  
Debt Instrument [Line Items]  
Debt Instrument, Face Amount $ 600
Debt Instrument, Interest Rate, Stated Percentage 5.85%