Inventory (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Inventory [Line Items]
Inventory, Raw Materials, Gross		$ 3,037	$ 1,717
Inventory, Work in Process, Gross		2,031	1,119
Inventory, Finished Goods, Gross		8,944	6,311
Inventory, Net	[1]	14,012	9,147
Deferred Costs and Other Assets		400	1,300
Inventory Write-down		$ 114	$ 1,800	$ 112

[1] unaudited