Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 7,762	$ 5,378
Less accumulated depreciation and amortization	(4,846)	(3,899)
Property and equipment, Net	2,916	1,479
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	5,801	3,665
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	652	550
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 1,309	$ 1,163