Balance Sheet Components - Components 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	$ 43,958	$ 42,395
Less: accumulated depreciation	(28,967)	(25,864)
Property and equipment, net	14,991	16,531
Lab equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	9,035	8,900
Manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	10,502	9,181
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	4,706	4,779
Furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	816	816
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 18,899	$ 18,719