v3.26.1
Income Taxes - NPC - Reconciliation of Effective Income Tax Rate (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Amount    
U.S. federal statutory income tax rate $ 184 $ 200
Energy-related tax credits (564) (560)
Effects of ratemaking (19) (25)
Total $ (430) $ (399)
Percent    
U.S. federal statutory income tax rate 21.00% 21.00%
Energy-related tax credits (64.20%) (58.80%)
Effects of ratemaking (2.30%) (2.60%)
Effective income tax rate (49.00%) (41.80%)
NPC    
Amount    
U.S. federal statutory income tax rate $ 3 $ (2)
Energy-related tax credits (1) 0
Effects of ratemaking 0 1
Total $ 2 $ (1)
Percent    
U.S. federal statutory income tax rate 21.00% 21.00%
Energy-related tax credits (5.60%) 0.00%
Effects of ratemaking 0.00% (9.90%)
Effective income tax rate 15.40% 11.10%