Property and Equipment, Net - Schedule of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 34,913	$ 25,266
Less: Accumulated depreciation and amortization	(21,549)	(18,969)
Property and equipment, net	13,364	6,297
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	13,714	12,616
IT Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,701	2,346
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,523	8,200
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	340	330
Construction in Process [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,635	$ 1,774