Component of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Office and computer equipment	$ 1,105	$ 1,094
Software	886	874
Leasehold improvements	990	927
Manufacturing equipment	572	251
Property and equipment, Gross	3,553	3,146
Less: accumulated depreciation	(2,972)	(2,615)
Property and equipment, net	$ 581	$ 531