Inventories, net (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 46,291	$ 55,878
Work in progress	54,325	51,251
Finished goods	188,326	192,632
Inventory, gross, Total	288,942	299,761
Less: allowance for obsolete and excess inventory	(94,429)	(108,567)
Total inventory	$ 194,513	$ 191,194