Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 320,315	$ 314,200
Accumulated depreciation	(170,476)	(162,912)
Property, plant and equipment, Net	149,839	151,288
Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	5,209	5,122
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	44,610	44,116
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	259,406	250,936
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	2,374	5,315
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 8,716	$ 8,711