CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue:
Revenue from collaborative arrangements (including amounts from a related party: three months-2013-$415; 2012-$1,430; nine months-2013-$3,059; 2012-$4,291)	$ 439	$ 1,430	$ 3,110	$ 129,960
Operating expenses:
Research and development	33,395	27,026	91,550	89,778
Selling, general and administrative	12,282	7,754	31,971	23,201
Total operating expenses	45,677	34,780	123,521	112,979
Income (loss) from operations	(45,238)	(33,350)	(120,411)	16,981
Other income (expense), net	(37)		6,734
Interest income	192	158	567	304
Interest expense	(1,902)	(1,500)	(7,662)	(4,503)
Net income (loss)	$ (46,985)	$ (34,692)	$ (120,772)	$ 12,782
Net income (loss) per share:
Basic net income (loss) per share (in dollars per share)	$ (0.44)	$ (0.37)	$ (1.20)	$ 0.14
Diluted net income (loss) per share (in dollars per share)	$ (0.44)	$ (0.37)	$ (1.20)	$ 0.14
Shares used to compute basic earnings per share (in shares)	106,925	95,027	100,321	89,271
Shares used to compute diluted earnings per share (in shares)	106,925	95,027	100,321	91,713