FAIR VALUE MEASUREMENTS (Level 3 Reconciliation) (Details) - Level 3 - Price Risk Management Instruments - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] | ||||
| Asset balance, beginning of period | $ 78 | $ 136 | $ 153 | $ 199 |
| Included in regulatory assets and liabilities or balancing accounts | 2 | 0 | (73) | (63) |
| Asset balance, end of period | $ 80 | $ 136 | $ 80 | $ 136 |