CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue:
Revenue from collaboration agreement	$ 288,416	$ 286,963	$ 265,350
Product revenue	63,955
Royalty revenue	8,294
Contract revenue from collaborations	1,500	160,211
License revenue			59,165
Total revenue	362,165	447,174	324,515
Operating expenses:
Cost of goods sold (excludes amortization of certain intangible assets)	1,328
Research and development	325,256	268,060	185,740
Selling, general and administrative	224,164	167,959	114,167
Contingent consideration expense (benefit)	69,173	(93,468)	92,930
Lease termination exit costs		6,317
Intangible asset amortization	9,331
Total operating expenses	629,252	348,868	392,837
Income (loss) from operations	(267,087)	98,306	(68,322)
Investment income, net	2,678	2,405	2,829
Interest expense	(21,785)	(20,224)	(19,400)
Other income (expense)	1,638	(4,103)	(773)
Income (loss) before provision (benefit) for income taxes	(284,556)	76,384	(85,666)
Provision (benefit) for income taxes	(96,769)	274	(819)
Net income (loss)	$ (187,787)	$ 76,110	$ (84,847)
Basic net income (loss) per share (in dollars per share)	$ (2.88)	$ 1.20	$ (1.35)
Diluted net income (loss) per share (in dollars per share)	$ (2.88)	$ 1.19	$ (1.35)
Shares used in computing basic net income (loss) per share (in shares)	65,148	63,422	62,618
Shares used in computing diluted net income (loss) per share (in shares)	65,148	64,010	62,618