Condensed Consolidated Statements of Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues:
Total revenues	$ 1,061,731	$ 213,263	$ 1,574,243	$ 626,909
Costs and expenses:
Cost of sales	78,296	10,827	155,962	32,024
Research and development	217,670	196,119	610,945	518,313
Selling, general and administrative	127,579	96,101	375,470	258,703
Total costs and expenses	423,545	303,047	1,142,377	809,040
Income (loss) from operations	638,186	(89,784)	431,866	(182,131)
Investment and other income (loss), net	1,223	(2,129)	17,951	(2,349)
Income (loss) before income taxes	639,409	(91,913)	449,817	(184,480)
Provision for income taxes	(3,242)	0	(3,242)	0
Net income (loss)	$ 636,167	$ (91,913)	$ 446,575	$ (184,480)
Net income (loss) per share - basic (in dollars per share)	$ 3.65	$ (0.55)	$ 2.58	$ (1.13)
Net income (loss) per share - diluted (in dollars per share)	$ 3.50	$ (0.55)	$ 2.47	$ (1.13)
Shares used in computation of per share amounts - basic (in shares)	174,460	168,109	173,409	163,428
Shares used in computation of per share amounts - diluted (in shares)	181,877	168,109	180,939	163,428
Comprehensive income (loss):
Net income (loss)	$ 636,167	$ (91,913)	$ 446,575	$ (184,480)
Other comprehensive income (loss):
Unrealized gain (loss) on securities available-for-sale, net of tax	(790)	(177)	441	297
Foreign currency translation gain (loss)	172	(7)	180	45
Total other comprehensive income (loss)	(618)	(184)	621	342
Comprehensive income (loss)	635,549	(92,097)	447,196	(184,138)
Product [Member]
Revenues:
Total revenues	267,494	167,582	706,473	461,563
Royalty [Member]
Revenues:
Total revenues	35,924	27,261	87,520	66,218
License and Service [Member]
Revenues:
Total revenues	$ 758,313	$ 18,420	$ 780,250	$ 99,128