Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue	$ 152,915	$ 114,617	$ 1,193,323
Operating costs and expenses:
Cost of goods sold	19,477	21,374	24,412
Research and development	408,678	434,566	399,536
General and administrative	104,682	98,712	81,443
Impairment of assets and other costs for terminated program	45,189	0	0
Total operating costs and expenses	578,026	554,652	505,391
Income (loss) from operations	(425,111)	(440,035)	687,932
Non-operating income (expense):
Interest expense	(6,851)	(21,310)	(21,582)
Non-cash interest expense on liability related to sale of future royalties	(30,267)	(25,044)	(21,196)
Interest income and other income (expense), net	18,282	46,335	37,571
Total non-operating expense, net	(18,836)	(19)	(5,207)
Income (loss) before provision for income taxes	(443,947)	(440,054)	682,725
Provision for income taxes	493	613	1,412
Net income (loss)	$ (444,440)	$ (440,667)	$ 681,313
Net income (loss) per share
Basic ( in dollars per share)	$ (2.49)	$ (2.52)	$ 4.02
Diluted (in dollars per share)	$ (2.49)	$ (2.52)	$ 3.78
Weighted average shares outstanding used in computing net income (loss) per share
Basic (in shares)	178,581	174,993	169,600
Diluted (in shares)	178,581	174,993	180,119
Product sales
Revenue:
Total revenue	$ 17,504	$ 20,117	$ 20,774
Royalty revenue
Revenue:
Total revenue	30,999	41,222	41,976
Non-cash royalty revenue related to sale of future royalties
Revenue:
Total revenue	48,563	36,303	33,308
License, collaboration and other revenue
Revenue:
Total revenue	$ 55,849	$ 16,975	$ 1,097,265