Leases - Maturity Analysis of Operating and Finance Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Leases
September 30, 2022	$ 7,434
September 30, 2023	6,110
September 30, 2024	5,180
September 30, 2025	4,765
September 30, 2026	4,637
Thereafter	29,784
Total undiscounted future minimum lease payments	57,910
Less: imputed interest	(9,035)
Operating leases	48,875	$ 55,187
Finance Lease
September 30, 2022	116
September 30, 2023	117
September 30, 2024	119
September 30, 2025	121
September 30, 2026	123
Thereafter	1,133
Total undiscounted future minimum lease payments	1,729
Less: imputed interest	(197)
Finance leases	$ 1,532	$ 1,598