Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 3,003	$ 3,316
Finished goods	6,523	6,598
Reserves for excess, obsolete, and slow moving inventories and valuation reserves	(3,787)	(4,196)
Inventories, net	$ 5,739	$ 5,718