CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenue (including amounts from a related party: three months-2012-$1,430; 2011-$2,456; six months-2012-$2,860; 2011-$4,913)	$ 1,430	$ 6,389	$ 128,529	$ 12,719
Operating expenses:
Research and development	29,549	22,798	62,751	43,262
General and administrative	7,590	7,248	15,447	14,417
Total operating expenses	37,139	30,046	78,198	57,679
Income (loss) from operations	(35,709)	(23,657)	50,331	(44,960)
Interest income	90	118	145	263
Interest expense	(1,501)	(1,506)	(3,002)	(3,015)
Net income (loss)	$ (37,120)	$ (25,045)	$ 47,474	$ (47,712)
Net income (loss) per share:
Basic net income (loss) per share (in dollars per share)	$ (0.42)	$ (0.31)	$ 0.55	$ (0.59)
Diluted net income (loss) per share (in dollars per share)	$ (0.42)	$ (0.31)	$ 0.53	$ (0.59)
Shares used to compute basic earnings per share (in shares)	89,169	81,811	86,379	81,415
Shares used to compute diluted earnings per share (in shares)	89,169	81,811	95,044	81,415