Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Finance lease cost:
Amortization of finance leases	$ 50	$ 29	$ 152	$ 381
Interest on lease liabilities	19	17	61	53
Operating lease cost	706	719	2,042	2,265
Sublease income	(50)	(50)	(150)	(117)
Total lease cost	$ 725	$ 715	$ 2,105	$ 2,582