Significant agreements - Summary of Contract Assets and Liabilities (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2026	Dec. 31, 2025
Contract liabilities:
Beginning Balance	$ 38,469,000	$ 101,658,000
Additions	969,000	960,000
Deductions	(35,573,000)	(70,586,000)
Impact of Exchange Rates	(173,000)	6,437,000
Ending Balance	3,692,000	38,469,000
Contract assets
Contract assets	0	0
Bayer collaboration deferred revenue
Contract liabilities:
Beginning Balance	34,629,000	39,960,000
Additions	969,000	960,000
Deductions	(35,573,000)	(8,920,000)
Impact of Exchange Rates	(25,000)	2,629,000
Ending Balance	0	34,629,000
Novartis collaboration deferred revenue
Contract liabilities:
Beginning Balance	0	44,073,000
Additions		0
Deductions		(46,985,000)
Impact of Exchange Rates		2,912,000
Ending Balance	0	0
Ionis collaboration deferred revenue
Contract liabilities:
Beginning Balance	3,840,000	3,587,000
Additions	0	0
Deductions	0	0
Impact of Exchange Rates	(148,000)	253,000
Ending Balance	3,692,000	3,840,000
Ionis collaboration deferred revenue \| Deferred revenue material rights option
Contract liabilities:
Ending Balance	3,700,000
Genentech collaboration deferred revenue
Contract liabilities:
Beginning Balance	0	14,038,000
Additions		0
Deductions		(14,681,000)
Impact of Exchange Rates		643,000
Ending Balance	$ 0	$ 0