Property, Plant and Equipment - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) a	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$ 315,980	$ 310,256
Depreciation expense		14,700	14,200	$ 14,300
Proceeds from sales of property, plant and equipment		55	4,349	35
Gain (loss) on disposal of property, plant and equipment		$ (1,738)	185	$ (649)
Olive Branch Assets [Member]
Property, Plant and Equipment [Line Items]
Proceeds from sales of property, plant and equipment	$ 4,200
Gain (loss) on disposal of property, plant and equipment	$ 100
Area of land owned | a		62
Construction in Process [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$ 5,954	$ 4,172