Employee Benefits - Benefit Obligation Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in Benefit Obligation
Benefit obligation at the beginning of the period	$ 19,746	$ 19,214	$ 18,927
Service cost	493	392	335
Interest cost	349	485	658
Payments	(1,913)	(1,913)	(1,913)
Actuarial loss (gain)	(740)	1,568	1,207
Benefit obligation at the end of the period	$ 17,935	$ 19,746	$ 19,214