Selected Balance Sheet Data Balance Sheet Related Disclosures, Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
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|---|---|---|---|---|
| Balance Sheet Related Disclosures [Abstract] | ||||
| Electric plant | $ 13,312 | $ 12,210 | ||
| Plant to be retired | [1] | 161 | 162 | |
| Construction work in progress | 1,667 | 1,117 | ||
| Total property, plant and equipment | 15,140 | 13,489 | ||
| Less accumulated depreciation | (3,294) | (3,063) | ||
| Property, plant and equipment, net | $ 11,846 | $ 10,426 | ||
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