Regulatory Matters - Schedule of Changes in The Deferred Fuel and Purchased Power Regulatory Asset (Details) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Change in regulatory asset | ||
| Deferred fuel and purchased power costs | $ 69,325 | $ 95,850 |
| Amounts charged to customers | (279,830) | (201,035) |
| APS | ||
| Change in regulatory asset | ||
| Deferred fuel and purchased power costs | 69,325 | 95,850 |
| Amounts charged to customers | (279,830) | (201,035) |
| Power Supply Adjustor (PSA) | ACC | APS | ||
| Change in regulatory asset | ||
| Balance at beginning of period | 149,068 | 287,597 |
| Deferred fuel and purchased power costs | 69,325 | 95,850 |
| Amounts charged to customers | (279,830) | (201,035) |
| Balance at end of period | $ (61,437) | $ 182,412 |