Inventories (Schedule of Inventory, Current) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Finished goods	$ 143,147	$ 133,161
Work in process	11,024	10,243
Raw materials	14,040	12,164
Total inventory	$ 168,211	$ 155,568