Investments - Schedule of Amortized Cost and Fair Value of the Trust Investments (Details) - SCE - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Fair Value Measurements | ||
| Fair Values | $ 4,457 | $ 4,535 |
| Deferred tax liabilities on net unrealized gains | 433 | 455 |
| Total debt securities and other | ||
| Fair Value Measurements | ||
| Amortized Costs | 2,376 | 2,382 |
| Fair Values | 2,609 | 2,626 |
| Municipal bonds | ||
| Fair Value Measurements | ||
| Amortized Costs | 720 | 718 |
| Fair Values | 841 | 899 |
| Government and agency securities | ||
| Fair Value Measurements | ||
| Amortized Costs | 1,121 | 1,149 |
| Fair Values | 1,246 | 1,367 |
| Corporate bonds | ||
| Fair Value Measurements | ||
| Amortized Costs | 347 | 315 |
| Fair Values | 388 | 380 |
| Short-term investments and receivables/(payables) | ||
| Fair Value Measurements | ||
| Amortized Costs | 188 | 200 |
| Fair Values | 134 | (20) |
| Repurchase Agreements | ||
| Fair Value Measurements | ||
| Fair Values | 22 | 27 |
| Equity securities | ||
| Fair Value Measurements | ||
| Fair Values | $ 1,848 | $ 1,909 |