CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenue:
Revenue from collaboration agreement	$ 70,307	$ 72,031
Product revenue	64,008
Royalty revenue	9,177
Contract revenue from collaboration	2,000
Total revenue	145,492	72,031
Operating expenses:
Cost of goods sold (excludes amortization of certain intangible assets)	1,968
Research and development	91,302	80,660
Selling, general and administrative	72,545	38,944
Contingent consideration expense (benefit)	2,930	3,178
Intangible asset amortization	5,220
Total operating expenses	173,965	122,782
Income (loss) from operations	(28,473)	(50,751)
Investment income, net	602	758
Interest expense	(5,626)	(5,296)
Other income (expense)	(156)	(905)
Income (loss) before provision (benefit) for income taxes	(33,653)	(56,194)
Provision (benefit) for income taxes	18	18
Net income (loss)	$ (33,671)	$ (56,212)
Basic and diluted net income (loss) per share (in dollars per share)	$ (0.47)	$ (0.88)
Shares used in computing basic and diluted net income (loss) per share (in shares)	71,087	63,697