Leases - Lease cost information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases
Operating lease cost	$ 1,962	$ 1,775	$ 1,792
Less: sublease income	(91)	(89)	(64)
Total lease expense	$ 1,871	$ 1,686	$ 1,728