Risk Management and Hedging Activities - PAC - Not Designated as Hedging Contracts (Details) - PAC - Not Designated as Hedging - Commodity derivatives - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Roll Forward] | ||
| Beginning balance | $ 137 | $ 97 |
| Changes in fair value recognized in regulatory assets | 34 | 10 |
| Net gains reclassified to operating revenue | 7 | 8 |
| Net losses reclassified to cost of fuel and energy | (67) | (34) |
| Ending balance | $ 111 | $ 81 |