Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Collaboration revenue	$ 181,696	$ 60,389	$ 62,508
Operating expenses:
Research and development expenses	95,628	73,432	72,228
Selling, general and administrative expenses	112,282	29,887	23,005
Total operating expenses	207,910	103,319	95,233
Loss from operations	(26,214)	(42,930)	(32,725)
Other income (expense), net:
Interest expense	(14,985)
Interest income	229	94	317
Other income (expense), net	(280)	(336)	(57)
Total other income (expense), net	(15,036)	(242)	260
Net loss before income tax (expense) benefit	(41,250)	(43,172)	(32,465)
Income tax (expense) benefit	(7)	4,331	(1,572)
Net loss	$ (41,257)	$ (38,841)	$ (34,037)
Basic and diluted net loss per common share	$ (0.56)	$ (0.56)	$ (0.50)
Weighted-average common shares used in the calculation of basic and diluted net loss per common share	73,480	69,921	68,579