Inventories, net - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 65,540	$ 70,188
Work in progress	66,686	65,382
Finished goods	227,429	239,083
Inventory, gross, Total	359,655	374,653
Less: allowance for obsolete and excess inventory	(83,650)	(83,566)
Net inventory	$ 276,005	$ 291,087