Financing and Operating Leases - Operating and Financing Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Leases
Operating lease right-of-use assets, net of amortization	$ 9,260	$ 7,183
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant, Equipment and Operating Lease Right-of-Use Asset	Property, Plant, Equipment and Operating Lease Right-of-Use Asset
Operating lease liability (current)	$ 1,781	$ 2,267
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued Liabilities, Current	Accrued Liabilities, Current
Long-term operating liability	$ 8,034	$ 5,491
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Total operating lease liabilities	$ 9,815	$ 7,758
Property, equipment and leasehold improvements	88,940	87,312
Accumulated depreciation	(59,853)	(55,092)
Total property, equipment and leasehold improvements, net	38,347	39,403
Financing lease liability (current)	$ 1,768	$ 2,140
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued Liabilities, Current	Accrued Liabilities, Current
Long-term financing liability	$ 2,183	$ 3,052
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Total financing lease liabilities	$ 3,951	$ 5,192
Financing leases
Leases
Property, equipment and leasehold improvements	7,676	9,974
Accumulated depreciation	(2,188)	(2,422)
Total property, equipment and leasehold improvements, net	$ 5,488	$ 7,552