Inventories - Summary of Inventories (Detail) - USD ($)
$ in Thousands
Sep. 30, 2016
Jun. 30, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Dec. 31, 2014
Inventory Disclosure [Abstract]            
Finished goods $ 16,139   $ 18,427      
Semi-finished goods and work-in-process 55,744   47,131      
Raw materials 6,821   5,987      
Materials in-transit 1,842   2,107      
Less: inventory reserve (8,490) $ (14,997) (16,033) $ (21,640) $ (31,361) $ (47,488)
Inventories, net $ 72,056   $ 57,619