Balance Sheets Details (Property and Equipment, net) (Details) - USD ($)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 35,631,000		$ 37,288,000
Less: accumulated depreciation and amortization		(32,476,000)		(31,452,000)
Less: impairment of laboratory equipment	$ (1,800,000)	0	$ (1,841,000)	(1,841,000)
Property and equipment, net		3,155,000		3,995,000
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		21,281,000		23,002,000
Property and equipment, net	$ 0		$ 0
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		9,782,000		9,773,000
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		3,271,000		3,262,000
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		1,227,000		1,227,000
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 70,000		$ 24,000