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Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Deferred tax assets: |  |
Advances and contributions | $ 28,183 | $ 26,744
Unamortized investment tax credit | 1,141 | 1,061
Pensions, postretirement benefits and stock-based compensation | 11,749 | 12,529
Debt premium, net | 2,734 | 3,446
California franchise tax | 257 | 503
Deferred revenue | 0 | 0
Tax related regulatory liability | 22,572 | 23,112
Other | 9,560 | 6,337
Total deferred tax assets | 76,196 | 73,732
Deferred tax liabilities: |  |
Utility plant | 304,002 | 277,085
Pension and postretirement | 9,272 | 9,068
Deferred gain and other-property | 608 | 608
Regulatory asset - business combinations debt premium, net | 2,734 | 3,446
Intangibles | 2,193 | 2,443
Deferred revenue | 2,330 | 1,418
Tax related regulatory asset | 57,503 | 50,728
Other | 5,447 | 4,979
Total deferred tax liabilities | 384,089 | 349,775
Net deferred tax liabilities | $ 307,893 | $ 276,043

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