Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenue:
Revenue from collaboration agreement	$ 67,956	$ 68,773	$ 135,101	$ 131,676
Total revenue	67,956	68,773	135,101	131,676
Operating expenses:
Research and development	63,045	43,251	125,538	86,826
Selling, general and administrative	38,236	26,647	72,707	51,368
Contingent consideration	5,755	92,037	17,250	95,485
Lease termination exit cost	10,727		10,727
Total operating expenses	117,763	161,935	226,222	233,679
Loss from operations	(49,807)	(93,162)	(91,121)	(102,003)
Investment income, net	645	780	1,293	1,569
Interest expense	(5,041)	(4,800)	(10,042)	(9,525)
Other expense	(340)		(3,801)
Loss before provision (benefit) for income taxes	(54,543)	(97,182)	(103,671)	(109,959)
Provision (benefit) for income taxes			32	(732)
Net loss	$ (54,543)	$ (97,182)	$ (103,703)	$ (109,227)
Basic net loss per share	$ (0.86)	$ (1.55)	$ (1.64)	$ (1.75)
Diluted net loss per share	$ (0.86)	$ (1.55)	$ (1.64)	$ (1.75)
Shares used in computing basic net loss per share	63,415	62,627	63,212	62,491
Shares used in computing diluted net loss per share	63,415	62,627	63,212	62,491