Inventories, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Finished goods	$ 73,046	$ 73,027
Work in process	16,041	14,719
Raw materials and supplies	93,401	87,047
Inventories, net	182,488	174,793
Inventory valuation reserves	$ 29,600	$ 33,500