Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory.
Raw materials and supplies	$ 23,705	$ 18,502
Work-in-process	5,567	237
Finished goods	3,480	5,997
Total inventory	32,752	24,736
Inventory on consignment	$ 2,200	$ 1,600