Property, Plant and Equipment, Net - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property Plant and Equipment [Line Items]
Plant and equipment under capital leases	$ 100,000	$ 100,000
Depreciation expense	9,800,000	9,800,000	$ 10,100,000
Property, plant and equipment, gross	156,378,000	140,568,000
Construction in Progress [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	11,139,000	5,138,000
Statesboro, Georgia [Member] | Construction in Progress [Member]
Property Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,200,000	2,300,000
Maximum [Member]
Property Plant and Equipment [Line Items]
Amortization under capital leases	$ 100,000	$ 100,000	$ 100,000