v3.3.1.900
Inventories (Details) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Inventory Disclosure [Abstract]    
Finished goods $ 9,589 $ 12,393
Raw materials and precious metals 9,055 9,333
Parts and supplies 18,885 13,888
Inventories $ 37,529 $ 35,614