Leases - Net Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net lease expense
Operating lease expense	$ 9,432	$ 9,169	$ 9,158
Short-term lease expense	246	397	487
Variable lease expense	2,204	2,353	2,152
Finance lease expense:
Amortization of right-of-use assets	3	3	3
Interest on lease liabilities		1	2
Finance lease right-of use assets	0
Total finance lease expense	3	4	5
Less: Sublease income	(744)	(1,222)	(1,073)
Net lease expense	$ 11,141	$ 10,701	$ 10,729