Significant agreements - Summary of Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Contract liabilities:
Beginning Balance	$ 71,340	$ 35,156
Additions	10,000	49,056
Deductions	(11,278)	(11,697)
Impact of Exchange Rates	(11,922)	(1,175)
Ending Balance	58,140	71,340
Ionis
Contract liabilities:
Beginning Balance	34,115	3,000
Additions	0	36,002
Deductions	(6,764)	(4,242)
Impact of Exchange Rates	(5,190)	(645)
Ending Balance	22,161	34,115
Genentech
Contract liabilities:
Beginning Balance	34,436	27,579
Additions	10,000	13,000
Deductions	(3,144)	(5,660)
Impact of Exchange Rates	(6,475)	(483)
Ending Balance	34,817	34,436
Dementia Discovery Fund
Contract liabilities:
Beginning Balance	428	821
Additions	0	0
Deductions	(205)	(391)
Impact of Exchange Rates	(53)	(2)
Ending Balance	170	428
AstraZeneca
Contract liabilities:
Beginning Balance	2,361	3,756
Additions	0	54
Deductions	(1,165)	(1,404)
Impact of Exchange Rates	(204)	(45)
Ending Balance	$ 992	$ 2,361