v3.26.1
Borrowings and Other Financing Instruments - Letters of Credit (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Line of Credit Facility [Abstract]    
Term of letters of credit (in years) 1 year  
Short-term debt $ 0 $ 260
Line of Credit Facility [Line Items]    
Term of letters of credit (in years) 1 year  
Short-term debt $ 0 260
Letter of Credit    
Line of Credit Facility [Abstract]    
Short-term debt 48 48
Line of Credit Facility [Line Items]    
Short-term debt 48 $ 48
Letter of Credit | Continuing Letter of Credit Agreement    
Line of Credit Facility [Abstract]    
Short-term debt 1  
Line of Credit Facility, Maximum Borrowing Capacity 50  
Line of Credit Facility [Line Items]    
Short-term debt 1  
Line of Credit Facility, Maximum Borrowing Capacity $ 50