Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other Accrued Liabilities [Abstract]
Accrued warranty, current	$ 150	$ 109
Accrued compensation, including commissions and vacation	1,024	785
Accrued sales and other taxes	822	904
Distributor rights liability, current	0	85
Accrued professional fees and other accrued liabilities	334	477
Total other accrued liabilities	$ 2,330	$ 2,360