Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 21,130	$ 14,454
Less accumulated depreciation	(7,373)	(4,979)
Property and equipment, net	13,757	9,475
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,259	2,684
Lab and clean room equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,971	4,564
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,271	4,577
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,629	$ 2,629