v3.26.1
Income Taxes - NPC - Reconciliation of Effective Income Tax Rate (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Amount        
U.S. federal statutory income tax rate $ 163 $ 115 $ 347 $ 315
Energy-related tax credits (415) (390) (979) (950)
Effects of ratemaking (30) (20) (49) (45)
Total $ (333) $ (357) $ (763) $ (756)
Percent        
U.S. federal statutory income tax rate 21.00% 21.00% 21.00% 21.00%
Energy-related tax credits (53.50%) (71.50%) (59.20%) (63.40%)
Effects of ratemaking (3.70%) (3.70%) (2.90%) (3.00%)
Effective income tax rate (42.90%) (65.60%) (46.10%) (50.50%)
NPC        
Amount        
U.S. federal statutory income tax rate $ 25 $ 13 $ 28 $ 11
Energy-related tax credits (7) (4) (8) (4)
Effects of ratemaking (4) (3) (4) (2)
Total $ 14 $ 6 $ 16 $ 5
Percent        
U.S. federal statutory income tax rate 21.00% 21.00% 21.00% 21.00%
Energy-related tax credits (5.90%) (6.70%) (5.90%) (7.30%)
Effects of ratemaking (3.30%) (5.30%) (3.20%) (4.50%)
Effective income tax rate 11.80% 9.00% 11.90% 9.20%