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Employee Benefit Plans, Changes in Benefit Obligation and Plan Assets (Details) - Defined Benefit Pension Plans Combined [Member] - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Employee Benefit Plans [Abstract]    
Maximum period of eligible service 30 years  
Change in Benefit Obligation [Abstract]    
Pension benefit obligation, beginning of year $ 54,106 $ 47,530
Service cost 1,086 938
Interest cost 1,209 1,457
Actuarial (gain) loss (3,045) 6,165
Benefit payments (1,826) (1,984)
Pension benefit obligation, end of year 51,530 54,106
Change in Plan Assets [Abstract]    
Fair value of plan assets, beginning of year 56,315 49,349
Actual return on plan assets 8,795 6,650
Employer contributions 2,300 2,300
Benefits paid (1,826) (1,984)
Fair value of plan assets, end of year 65,584 56,315
Funded status of plans at end of year $ 14,054 $ 2,209
Change in discount rate 0.35% (0.80%)
Threshold for amortization of gains and losses 10.00%  
Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets [Abstract]    
Net gain (loss) arising during the period $ (8,189) $ 2,713
Recognized net actuarial loss (483) (370)
Recognized prior service credit 13 13
Total changes in regulatory asset during the year (8,659) 2,356
Amounts Recognized in Regulatory Assets that Have Not Yet Been Recognized as Components of Net Periodic Benefit Cost [Abstract]    
Net loss 1,825 10,497
Prior service credit (50) (63)
Regulatory asset $ 1,775 $ 10,434