Balance Sheets Details (Property and Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 51,341	$ 50,794
Less: accumulated depreciation	(37,780)	(34,172)
Property and equipment, net, excluding construction in progress	13,561	16,622
Property and equipment, net	13,809	16,650	[1]
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	35,311	33,776
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,108	11,099
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,419	4,388
Office equipment and furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,503	1,531
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 248	$ 28

[1] The Condensed Consolidated Balance Sheet as of December 31, 2012 has been derived from the audited consolidated financial statements as of that date, but does not include all disclosures including notes required by GAAP for complete financial statements.