Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 2,991	$ 3,316
Finished goods	7,106	6,598
Reserves for excess, obsolete, and slow moving inventories and valuation reserves	(3,663)	(4,196)
Inventories, net	$ 6,434	$ 5,718