Accrued Liabilities - Accrued Liabilities Schedule (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued compensation and benefits	$ 17,457	$ 15,366
Restructuring Reserve, Current	2,347	0
Accrued warranties	1,683	2,090	$ 2,571	$ 2,628
Professional and legal fees	1,810	1,793
Taxes other than income	5,013	4,077
General services administration liability	12,325	11,886
Other accrued liabilities	1,958	2,860
Total accrued liabilities	$ 42,593	$ 38,072