Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Collaboration revenue	$ 182,497	$ 129,188
Operating expenses:
Research and development expenses	77,587	44,676
Selling, general and administrative expenses	96,827	83,939
Total operating expenses	174,414	128,615
Income from operations	8,083	573
Other income (expense), net:
Interest expense	(680)	(5,608)
Other, net	(209)	137
Total other income (expense), net	(889)	(5,471)
Income (loss) before income tax (expense) benefit	7,194	(4,898)
Income tax (expense) benefit	(2,378)	1,780
Net income (loss)	$ 4,816	$ (3,118)
Basic net income (loss) per common share	$ 0.03	$ (0.02)
Diluted net income (loss) per common share	$ 0.03	$ (0.02)
Weighted average common shares used in the calculation of basic net income (loss) per common share	164,247	156,637
Weighted average common shares used in the calculation of diluted net income (loss) per common share	168,397	156,637