Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating leases:
Operating lease right-of-use assets	$ 23,586	$ 26,107
Current operating lease liabilities	5,466	5,557
Operating lease liabilities - less current portion	19,639	21,985
Total operating lease liabilities	25,105	27,542
Finance leases:
Property and equipment, at cost	1,342	1,813
Accumulated depreciation	(1,118)	(1,415)
Property and equipment, net	224	398
Current finance lease liabilities	164	278
Finance lease liabilities - less current portion	85	146
Total finance lease liabilities	$ 249	$ 424
Weighted Average Remaining Lease Term (in years):
Operating leases	5 years 11 months 1 day	6 years 6 months 18 days
Finance leases	1 year 9 months 25 days	1 year 11 months 4 days
Weighted Average Discount Rate:
Operating leases	5.68%	5.66%
Finance leases	5.12%	5.07%
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Lease liabilities	Lease liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Lease liabilities - less current portion	Lease liabilities - less current portion
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Liabilities	Liabilities
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, plant and equipment, net	Property, plant and equipment, net