Employee Benefit Plans - Changes in the Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, beginning	$ 18,080	$ 15,035
Service cost	345	261	$ 1,353
Interest cost	497	601	468
Actuarial experience and changes in actuarial assumptions	1,706	2,183
Projected benefit obligation, ending	$ 20,628	$ 18,080	$ 15,035