Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 2,672	$ 3,316
Finished goods	6,645	6,598
Reserves for excess, obsolete, and slow moving inventories and valuation reserves	(3,709)	(4,196)
Inventories, net	$ 5,608	$ 5,718