Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Inventories [Abstract]
Raw materials and supplies	$ 113,632	$ 120,811
Work in process	24,290	22,979
Finished products	81,263	80,118
Inventory reserves	(37,233)	(34,040)
Total Inventory	$ 181,952	$ 189,868