Property and Equipment - Summary of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 7,270	$ 5,316
Accumulated depreciation and amortization	(4,150)	(3,452)
Property and equipment, net	3,120	1,864
Machinery and Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	3,797	2,453
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	1,710	1,327
Furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	358	287
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 1,405	$ 1,249