CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (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
Revenue:
Revenue from collaboration agreement	$ 81,828	$ 72,704	$ 152,135	$ 144,736
Product revenue	61,037		125,045
Royalty revenue	10,161		19,338
Contract revenue from collaboration			2,000
Total revenue	153,026	72,704	298,518	144,736
Operating expenses:
Cost of goods sold (excludes amortization of intangible assets)	2,043		4,011
Research and development	102,761	76,356	194,063	157,017
Selling, general and administrative	87,512	48,907	160,057	87,851
Contingent consideration expense	3,022	53,214	5,952	56,392
Intangible asset amortization	5,221		10,441
Total operating expenses	200,559	178,477	374,524	301,260
Income (loss) from operations	(47,533)	(105,773)	(76,006)	(156,524)
Investment income, net	558	619	1,160	1,377
Interest expense	(5,712)	(5,374)	(11,338)	(10,670)
Other income (expense)	(464)	4,464	(620)	3,559
Income (loss) before provision (benefit) for income taxes	(53,151)	(106,064)	(86,804)	(162,258)
Provision (benefit) for income taxes	17	(15)	35	3
Net income (loss)	$ (53,168)	$ (106,049)	$ (86,839)	$ (162,261)
Basic and diluted net income (loss) per share (in dollars per share)	$ (0.73)	$ (1.65)	$ (1.20)	$ (2.54)
Shares used in computing basic and diluted net loss per share (in shares)	72,951	64,209	72,113	63,953