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Accounting For Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Parenthetical) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2018
Dec. 31, 2017
Regulatory Liability [Line Items]          
Federal statutory tax rate 21.00% 21.00% 21.00% 21.00% 35.00%
Regulatory liability, current $ 95,665 $ 77,149      
Effective income tax rate reconciliation, excess deferred income tax reversal amount     $ 8,476    
Washington Utilities and Transportation Commission [Member]          
Regulatory Liability [Line Items]          
Effective income tax rate reconciliation, excess deferred income tax reversal amount     8,400    
Washington Utilities and Transportation Commission [Member] | Income Tax Related [Member]          
Regulatory Liability [Line Items]          
Regulatory liability, current     $ 10,900