CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Total revenues	$ 382,282	$ 384,082
Costs and expenses:
Cost of product revenues (including definite-lived intangible amortization)	18,106	14,824
Research and development	303,103	407,920
Selling, general and administrative	121,498	87,229
Change in fair value of acquisition-related contingent consideration	6,685	7,356
Total costs and expenses	449,392	517,329
Loss from operations	(67,110)	(133,247)
Other income (expense), net	4,462	1,147
Interest expense	(385)	(5,939)
Unrealized gain (loss) on long term investments	22,679	(5,814)
Expense related to senior note conversions		(54,130)
Loss before provision (benefit) for income taxes	(40,354)	(197,983)
Provision (benefit) for income taxes	786	(10,900)
Net loss	$ (41,140)	$ (187,083)
Basic and diluted net loss per share (in dollars per share)	$ (0.19)	$ (0.96)
Shares used in computing basic and diluted net loss per share (in shares)	211,681	195,260
Product revenues, net
Revenues:
Total revenues	$ 334,505	$ 264,807
Product royalty revenues
Revenues:
Total revenues	47,716	29,221
Milestone revenues
Revenues:
Total revenues		90,000
Other revenues
Revenues:
Total revenues	$ 61	$ 54