Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue:
Total revenue	$ 114,617	$ 1,193,323	$ 307,711
Operating costs and expenses:
Cost of goods sold	21,374	24,412	30,547
Research and development	434,566	399,536	268,461
General and administrative	98,712	81,443	52,364
Impairment of equipment and other costs for terminated program	0	0	15,981
Total operating costs and expenses	554,652	505,391	367,353
Income (loss) from operations	(440,035)	687,932	(59,642)
Non-operating income (expense):
Interest expense	(21,310)	(21,582)	(22,085)
Non-cash interest expense on liability related to sale of future royalties	(25,044)	(21,196)	(18,869)
Interest income and other income (expense), net	46,335	37,571	4,520
Total non-operating expense, net	(19)	(5,207)	(36,434)
Income (loss) before provision for income taxes	(440,054)	682,725	(96,076)
Provision for income taxes	613	1,412	616
Net income (loss)	$ (440,667)	$ 681,313	$ (96,692)
Net income (loss) per share
Basic ( in dollars per share)	$ (2.52)	$ 4.02	$ (0.62)
Diluted (in dollars per share)	$ (2.52)	$ 3.78	$ (0.62)
Weighted average shares outstanding used in computing net income (loss) per share
Basic (in shares)	174,993	169,600	155,953
Diluted (in shares)	174,993	180,119	155,953
Product sales
Revenue:
Total revenue	$ 20,117	$ 20,774	$ 32,688
Royalty revenue
Revenue:
Total revenue	41,222	41,976	33,527
Non-cash royalty revenue related to sale of future royalties
Revenue:
Total revenue	36,303	33,308	30,531
License, collaboration and other revenue
Revenue:
Total revenue	$ 16,975	$ 1,097,265	$ 210,965