Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Collaboration revenue	$ 272,942	$ 181,696	$ 60,389
Operating expenses:
Research and development expenses	118,952	95,628	73,432
Selling, general and administrative expenses	176,231	112,282	29,887
Total operating expenses	295,183	207,910	103,319
Loss from operations	(22,241)	(26,214)	(42,930)
Other income (expense), net:
Interest expense	(20,249)	(14,985)
Interest income	193	229	94
Other expense, net	(201)	(280)	(336)
Total other income (expense), net	(20,257)	(15,036)	(242)
Net loss before income tax (expense) benefit	(42,498)	(41,250)	(43,172)
Income tax (expense) benefit	(115)	(7)	4,331
Net loss	$ (42,613)	$ (41,257)	$ (38,841)
Basic and diluted net loss per common share	$ (0.57)	$ (0.56)	$ (0.56)
Weighted-average common shares used in the calculation of basic and diluted net loss per common share	75,165	73,480	69,921