Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Collaboration revenue	$ 87,189	$ 46,154
Operating expenses:
Research and development expenses	45,919	24,908
Selling, general and administrative expenses	49,735	43,568
Total operating expenses	95,654	68,476
Loss from operations	(8,465)	(22,322)
Other income (expense), net:
Interest expense	(5,230)	(4,888)
Interest income	9	74
Other expense, net	(38)	(1)
Total other income (expense), net	(5,259)	(4,815)
Net loss before income tax benefit (expense)	(13,724)	(27,137)
Income tax benefit (expense)	59	(33)
Net loss	$ (13,665)	$ (27,170)
Basic and diluted net loss per common share	$ (0.18)	$ (0.36)
Weighted average common shares used in the calculation of basic and diluted net loss per common share	76,245	74,824