Regulatory Matters - Schedule of Changes in The Deferred Fuel and Purchased Power Regulatory Asset (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Change in regulatory asset | ||
| Deferred fuel and purchased power costs | $ 25,228 | $ 33,094 |
| Amounts charged to customers | (84,789) | (108,552) |
| APS | ||
| Change in regulatory asset | ||
| Deferred fuel and purchased power costs | 25,228 | 33,094 |
| Amounts charged to customers | (84,789) | (108,552) |
| Power Supply Adjustor (PSA) | ACC | APS | ||
| Change in regulatory asset | ||
| Balance at beginning of period | 287,597 | 463,195 |
| Deferred fuel and purchased power costs | 25,228 | 33,094 |
| Amounts charged to customers | (84,789) | (108,552) |
| Balance at end of period | $ 228,036 | $ 387,737 |