Leases - Supplemental Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases
Operating lease cost	$ 2,780	$ 3,090	$ 8,574	$ 9,121
Finance lease cost:
Amortization of leased assets	98	213	364	564
Interest on lease liabilities	4	19	22	75
Total finance lease cost	102	232	386	639
Sublease income	(1,259)	(905)	(3,644)	(2,692)
Net lease cost	$ 1,623	$ 2,417	$ 5,316	$ 7,068