Property, Plant and Equipment, at Cost (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 740,421	$ 672,850
Less: Accumulated depreciation	(367,954)	(319,473)
Total property, plant and equipment, net	372,467	353,377
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	68,562	68,562
Buildings and Leasehold Improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	205,534	163,333
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 466,325	$ 440,955