Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Operations [Abstract]
Collaboration revenue	$ 60,389	$ 62,508	$ 69,254
Operating expenses:
Research and development	73,432	72,228	87,728
Selling, general and administrative	29,887	23,005	28,983
Total operating expenses	103,319	95,233	116,711
Loss from operations	(42,930)	(32,725)	(47,457)
Other (expense) income, net	(242)	260	976
Net loss before income tax (benefit) expense	(43,172)	(32,465)	(46,481)
Income tax (benefit) expense	(4,331)	1,572	8,272
Net loss	$ (38,841)	$ (34,037)	$ (54,753)
Basic and diluted net loss per common share	$ (1.11)	$ (0.99)	$ (1.71)
Weighted-average common shares used in the calculation of basic and diluted net loss per common share	34,960	34,290	32,094