Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued payroll	$ 7,921	$ 11,693
Accrued rent	1,234	1,180
Accrued employee benefits	919	2,035
Accrued state and local taxes	218	951
Advance payments	371	441
Accrued product warranty	1,237	1,118
Accrued commission expenses	246	425
Accrued professional fees	174	181
Accrued other	1,038	1,079
Total accrued liabilities	$ 13,358	$ 19,103