Employee Benefit Plans - Changes in Projected Benefit Obligations for SERP (Details) - Supplemental Employee Retirement Plan - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Defined Benefit Change in Benefit Obligation [Roll Forward]      
Benefit obligation at beginning of year $ 1,923 $ 2,064 $ 2,174
Net periodic benefit cost:      
Interest cost 61 61 84
Actuarial loss (gain) 0 74 82
Total net period cost 61 135 166
Benefits paid (276) (276) (276)
Benefit obligation at end of year 1,708 1,923 2,064
Funded status:      
Accrued liability as of December 31 $ (1,708) $ (1,923) $ (2,064)
Discount rate used for benefit obligation 3.25% 3.25% 4.00%