Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
Lessee, operating lease, existence of option to extend [true false]	true
Components of lease expense
Operating lease costs	$ 4,377	$ 4,554	$ 4,507
Variable lease cost	1,136	959	1,235
Total	$ 5,513	5,513	5,742
Minimum
Operating Leases
Renewal term (in years)	5 years
Controlling Shareholders
Operating Leases
Payments under leases		203	236
Sublease income	$ 439	$ 277	$ 274