Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventories
Raw materials and supplies	$ 31,878	$ 41,996
Work in process	21,455	16,221
Finished goods	19,867	24,755
Total inventory	73,200	82,972
Less reserve for excess and obsolete inventories	(2,535)	(640)
Total inventory, net	$ 70,665	$ 82,332