Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Other Accrued Liabilities [Abstract]
Accrued warranty, current	$ 146	$ 109
Accrued compensation, including commissions and vacation	1,196	785
Accrued sales and other taxes	869	904
Distributor rights liability, current	0	85
Accrued professional fees and other accrued liabilities	486	477
Total other accrued liabilities	$ 2,697	$ 2,360