CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue:
Revenue	$ 141,919	$ 111,607
Expenses:
Cost of sales	4,170	2,578
Research, development and patent	161,126	139,801
Selling, general and administrative	34,127	61,199
Total operating expenses	199,423	203,578
Loss from operations	(57,504)	(91,971)
Other income (expense):
Investment income	1,993	4,643
Interest expense	(2,122)	(2,414)
Loss on investments	(6,625)	0
Other income	187	3
Loss before income tax expense	(64,071)	(89,739)
Income tax expense	(1,094)	(130)
Net loss	$ (65,165)	$ (89,869)
Basic net loss per share (in dollars per share)	$ (0.46)	$ (0.64)
Diluted net loss per share (in dollars per share)	$ (0.46)	$ (0.64)
Shares used in computing basic net loss per share (in shares)	141,599	140,770
Shares used in computing diluted net loss per share (in shares)	141,599	140,770
Commercial Revenue [Member]
Revenue:
Revenue	$ 72,285	$ 84,448
SPINRAZA Royalties [Member]
Revenue:
Revenue	53,818	59,986
TEGSEDI and WAYLIVRA Revenue, Net [Member]
Revenue:
Revenue	6,160	19,838
Licensing and Other Royalty Revenue [Member]
Revenue:
Revenue	12,307	4,624
Research and Development Revenue [Member]
Revenue:
Revenue	69,634	27,159
Collaborative Agreement Revenue [Member]
Revenue:
Revenue	49,784	27,159
Eplontersen Joint Development Revenue [Member]
Revenue:
Revenue	$ 19,850	$ 0