Property, Plant and Equipment, Net - Components of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Land		$ 260
Buildings and improvements	$ 6,036	8,189
Office furniture and equipment	4,581	4,675
Tooling and equipment	21,642	21,381
Transportation equipment	560	560
Construction in progress	3,411	3,011
Property, plant and equipment, at cost	36,230	38,076
Accumulated depreciation	(11,941)	(12,075)
Property, plant and equipment, net	$ 24,289	$ 26,001