Inventories (Schedule of Inventories) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw material	$ 42,661	$ 41,758
Work-in-process	10,598	12,268
Finished goods	33,113	35,586
Total inventories	$ 86,372	$ 89,612