Property, Plant and Equipment - Summary of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 334,152	$ 315,980
Accumulated depreciation	(217,008)	(212,870)
Total property, plant and equipment, net	117,144	103,110
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	50,240	49,403
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	233,464	228,107
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,625	1,620
Forklifts and Tractors [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	10,872	9,799
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	10,142	9,680
Construction in Process [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	16,392	5,954
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 11,417	$ 11,417