v3.26.1
Fair Value Measurements - MEC - Level 3 (Details) - MEC - Commodity - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Fair Value, Assets (Liabilities), Net, Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance $ (1) $ 1 $ (2) $ (2)
Changes in fair value recognized in regulatory assets (3) (1) (4) 0
Settlements 2 0 4 2
Ending balance $ (2) $ 0 $ (2) $ 0