Balance Sheet Components - Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Property and equipment	$ 165,126	$ 129,432
Less: Accumulated depreciation and amortization	(85,935)	(75,467)
Property, plant and equipment, net	79,191	53,965
Clinical and manufacturing equipment
Property, Plant and Equipment [Line Items]
Property and equipment	83,821	59,991
Computer hardware
Property, Plant and Equipment [Line Items]
Property and equipment	22,706	19,096
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment	20,346	18,972
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment	6,808	5,797
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	12,388	4,588
Building
Property, Plant and Equipment [Line Items]
Property and equipment	1,868	1,913
Land
Property, Plant and Equipment [Line Items]
Property and equipment	1,162	1,162
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment	$ 16,027	$ 17,913