Property, Plant and Equipment - Summary of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 359,040	$ 364,395
Less: accumulated depreciation	(167,031)	(157,341)
Property, plant and equipment, net	208,351	223,766
Buildings and related structures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	69,589	70,552
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	264,669	269,031
Vehicles and others [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	24,782	24,812
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 16,342	$ 16,712