Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Collaboration revenue	$ 200,478	$ 60,027	$ 435,757	$ 176,330
Operating expenses:
Research and development expenses	45,430	28,737	131,693	81,850
Selling, general and administrative expenses	63,165	39,288	165,695	124,746
Total operating expenses	108,595	68,025	297,388	206,596
Income (loss) from operations	91,883	(7,998)	138,369	(30,266)
Other income (expense), net:
Interest expense	(5,535)	(5,165)	(16,101)	(15,035)
Interest income	9	40	26	166
Other income (expense), net	55	(132)	(76)	(123)
Total other income (expense), net	(5,471)	(5,257)	(16,151)	(14,992)
Income (loss) before income tax expense	86,412	(13,255)	122,218	(45,258)
Income tax expense	(8,419)	(58)	(9,971)	(123)
Net income (loss)	$ 77,993	$ (13,313)	$ 112,247	$ (45,381)
Basic net income (loss) per common share	$ 1.01	$ (0.18)	$ 1.46	$ (0.60)
Diluted net income (loss) per common share	$ 0.96	$ (0.18)	$ 1.39	$ (0.60)
Weighted average common shares used in the calculation of basic net income (loss) per common share	77,056	75,255	76,629	75,032
Weighted average common shares used in the calculation of diluted net income (loss) per common share	81,223	75,255	80,724	75,032