v3.26.1
Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]                
Equity, attributable to parent (loss) $ 24,057   $ 24,057     $ 23,609    
Defined Benefit Pension and Postretirement Items                
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]                
Equity, attributable to parent (loss) (37) $ (39) (37) $ (39) $ (38) (38) $ (39) $ (39)
Losses reclassified from net accumulated other comprehensive loss [1] 1 0 1 0        
Net current period other comprehensive income (loss) 1 0 1 0        
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax 0 0 0 0        
Defined Benefit Pension and Postretirement Items | Interest Rate Swap                
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]                
Losses reclassified from net accumulated other comprehensive loss [2] 0 0 0 0        
Total                
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]                
Equity, attributable to parent (loss) (58) (66) (58) (66) (59) (63) (72) (68)
Losses reclassified from net accumulated other comprehensive loss [1] 1 0 1 0        
Net current period other comprehensive income (loss) 1 6 5 2        
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax 0 5 3 0        
Total | Interest Rate Swap                
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]                
Losses reclassified from net accumulated other comprehensive loss [2] 0 1 1 2        
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent                
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]                
Equity, attributable to parent (loss) (21) (27) (21) (27) $ (21) $ (25) $ (33) $ (29)
Losses reclassified from net accumulated other comprehensive loss [1] 0 0 0 0        
Net current period other comprehensive income (loss) 0 6 4 2        
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax 0 5 3 0        
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest Rate Swap                
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]                
Losses reclassified from net accumulated other comprehensive loss [2] $ 0 $ 1 $ 1 $ 2        
[1] Included in the computation of net periodic pension and postretirement benefit costs. See Note 9 for further information
[2] Included in interest charges.