CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Total revenues	$ 2,666,702	$ 2,158,759	$ 1,881,883
Costs and expenses:
Cost of product revenues (including definite-lived intangible amortization)	131,328	114,249	94,123
Research and development	2,215,942	1,154,111	1,197,957
Selling, general and administrative	516,922	468,711	434,407
Change in fair value of acquisition-related contingent consideration	23,385	19,682	26,173
Collaboration loss sharing	42,801
Total costs and expenses	2,930,378	1,756,753	1,752,660
Income (loss) from operations	(263,676)	402,006	129,223
Other income (expense), net	23,206	52,182	31,760
Interest expense	(2,174)	(1,855)	(1,543)
Unrealized gain (loss) on long term investments	10,426	34,458	(44,093)
Income (loss) before provision for income taxes	(232,218)	486,791	115,347
Provision for income taxes	63,479	39,885	5,854
Net (loss) income	$ (295,697)	$ 446,906	$ 109,493
Net income (loss) per share:
Basic	$ (1.36)	$ 2.08	$ 0.52
Diluted	$ (1.36)	$ 2.05	$ 0.51
Shares used in computing net income (loss) per share:
Basic	218,073	214,913	212,383
Diluted	218,073	217,657	215,635
Product revenues, net
Revenues:
Total revenues	$ 2,068,736	$ 1,774,922	$ 1,466,900
Product royalty revenues
Revenues:
Total revenues	392,966	306,337	234,780
Milestone and contract revenues
Revenues:
Total revenues	$ 205,000	$ 77,500	180,000
Other revenues
Revenues:
Total revenues			$ 203