CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue:
Revenue	$ 144,207	$ 159,767	$ 463,142	$ 435,478
Expenses:
Cost of sales	2,191	1,515	6,071	10,430
Research, development and patent	215,330	182,990	643,070	524,875
Selling, general and administrative	69,951	34,416	161,608	102,345
Total operating expenses	287,472	218,921	810,749	637,650
Loss from operations	(143,265)	(59,154)	(347,607)	(202,172)
Other income (expense):
Investment income	23,935	7,524	63,355	13,447
Interest expense	(4,203)	(2,139)	(8,102)	(6,391)
Interest expense related to sale of future royalties	(17,779)	0	(50,948)	0
Gain (loss) on investments	(1,943)	2,347	(1,753)	(10,616)
Other income (expense)	2,447	4,713	13,857	(7,923)
Loss before income tax expense	(140,808)	(46,709)	(331,198)	(213,655)
Income tax expense	(6,602)	(283)	(25,825)	(3,637)
Net loss	$ (147,410)	$ (46,992)	$ (357,023)	$ (217,292)
Basic net loss per share (in dollars per share)	$ (1.03)	$ (0.33)	$ (2.5)	$ (1.53)
Diluted net loss per share (in dollars per share)	$ (1.03)	$ (0.33)	$ (2.5)	$ (1.53)
Shares used in computing basic net loss per share (in shares)	143,317	141,950	143,052	141,782
Shares used in computing diluted net loss per share (in shares)	143,317	141,950	143,052	141,782
Commercial Revenue [Member]
Revenue:
Revenue	$ 84,081	$ 72,410	$ 229,746	$ 222,879
SPINRAZA Royalties [Member]
Revenue:
Revenue	67,253	61,647	178,511	175,092
Other Commercial Revenue [Member]
Revenue:
Revenue	16,828	10,763	51,235	47,787
Research and Development Revenue [Member]
Revenue:
Revenue	60,126	87,357	233,396	212,599
Collaborative Agreement Revenue [Member]
Revenue:
Revenue	44,167	69,250	173,513	157,282
Eplontersen Joint Development Revenue [Member]
Revenue:
Revenue	$ 15,959	$ 18,107	$ 59,883	$ 55,317