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Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Deferred Tax Assets |  |
Employee Benefits | $ 37,456 | $ 39,959
Regulatory Liabilities | 52,664 | 56,479
Tax Credit Carryforwards | 18,268 | 21,836
Cost of Removal | 35,374 | 32,993
Asset Retirement Obligations | 10,948 | 9,494
Net Operating Loss Carryforward | 2,289 | 2,336
Other | 19,449 | 11,310
Total Deferred Tax Assets | 176,448 | 174,407
Deferred Tax Liabilities |  |
Differences Related to Property | (375,120) | (347,885)
Retirement Benefits Regulatory Asset | (22,892) | (22,458)
Pension Expense | (26,034) | (24,875)
Other | (20,147) | (16,462)
Total Deferred Tax Liabilities | (444,193) | (411,680)
Deferred Income Taxes | $ (267,745) | $ (237,273)

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