v3.26.1
Other Comprehensive Income (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Accumulated other comprehensive loss at beginning of period     $ 13,206  
Accumulated other comprehensive loss at end of period $ 14,291   14,291  
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Accumulated other comprehensive loss at beginning of period (17) $ (18) (17) $ (18)
Net current period other comprehensive loss 1 1 1 1
Accumulated other comprehensive loss at end of period (16) (17) (16) (17)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest Rate Swap        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [1] 1 1 1 1
Defined Benefit and Postretirement Items        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Accumulated other comprehensive loss at beginning of period (1) (1) (1) (1)
Net current period other comprehensive loss 0 0 0 0
Accumulated other comprehensive loss at end of period (1) (1) (1) (1)
Defined Benefit and Postretirement Items | Interest Rate Swap        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [1] 0 0 0 0
Total        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Accumulated other comprehensive loss at beginning of period (18) (19) (18) (19)
Net current period other comprehensive loss 1 1 1 1
Accumulated other comprehensive loss at end of period (17) (18) (17) (18)
Total | Interest Rate Swap        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [1] $ 1 $ 1 $ 1 $ 1
[1] Included in interest charges