Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue:
Total revenue	$ 28,222	$ 38,018
Operating costs and expenses:
Cost of goods sold	$ 5,440	$ 6,646
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 118,463	$ 99,424
General and administrative	25,006	18,687
Total operating costs and expenses	148,909	124,757
Loss from operations	(120,687)	(86,739)
Non-operating income (expense):
Interest expense	(5,226)	(5,340)
Non-cash interest expense on liability related to sale of future royalties	(6,065)	(5,019)
Interest income and other income (expense), net	12,483	1,571
Total non-operating income (expense), net	1,192	(8,788)
Loss before provision for income taxes	(119,495)	(95,527)
Provision (benefit) for income taxes	(983)	265
Net loss	$ (118,512)	$ (95,792)
Basic and diluted net loss per share	$ (0.68)	$ (0.60)
Weighted average shares outstanding used in computing basic and diluted net loss per share	173,859	160,884
Product Sales [Member]
Revenue:
Total revenue	$ 4,398	$ 6,295
Royalty Revenue [Member]
Revenue:
Total revenue	11,390	11,076
Non-cash Royalty Revenue Related to Sale of Future Royalties [Member]
Revenue:
Total revenue	8,230	6,920
License, Collaboration and Other Revenue [Member]
Revenue:
Total revenue	$ 4,204	$ 13,727