CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Collaboration revenues:
Product revenue	$ 1,628	$ 19,352	$ 7,024	$ 41,382
Research and development revenue	2,733	2,511	4,940	4,709
Total collaboration revenue	4,361	21,863	11,964	46,091
Operating expenses:
Research and development	21,994	20,011	44,326	38,572
General and administrative	11,516	12,353	21,233	23,310
Total operating expenses	33,510	32,364	65,559	61,882
Operating loss	(29,149)	(10,501)	(53,595)	(15,791)
Other income:
Interest income	243	335	512	642
Other income	58		118
Total other income	301	335	630	642
Net loss	(28,848)	(10,166)	(52,965)	(15,149)
Basic and diluted net loss per share (in dollar per share)	$ (0.57)	$ (0.20)	$ (1.04)	$ (0.30)
Weighted average shares used in computing basic and diluted net loss per share (in shares)	50,746	50,354	50,690	50,297
Comprehensive loss:
Net loss	(28,848)	(10,166)	(52,965)	(15,149)
Net unrealized holding gains (losses) on available-for-sales marketable securities	(24)	(40)	(89)	67
Comprehensive loss	$ (28,872)	$ (10,206)	$ (53,054)	$ (15,082)