Accrued Liabilities - Schedule of Accrued liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued compensation and benefits	$ 17,392	$ 17,457
Accrued restructuring costs	1,115	2,347
Accrued warranties	1,616	1,683	$ 1,622	$ 2,090
Professional and legal fees	1,993	1,810
Taxes other than income	4,402	5,013
General services administration contract contingent liability (see Note 12)	0	12,325
Other accrued liabilities	1,737	1,958
Accrued liabilities	$ 28,255	$ 42,593