Collaboration agreements - Merck Immunosynthen Agreement (Details)	1 Months Ended	12 Months Ended
	Dec. 31, 2022 USD ($) license target performanceObligation	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) license target performanceObligation	Dec. 31, 2021 USD ($)
Collaboration agreements
Collaboration revenue		$ 36,855,000	$ 26,581,000	$ 43,000
Deferred revenue	$ 147,653,000	125,314,000	$ 147,653,000	$ 3,944,000
2022 Merck KGaA Agreement
Collaboration agreements
Number of targets designated | target	2		2
Upfront payment received	$ 30,000,000
Number of licenses | license	2		2
Performance obligations identified | performanceObligation	4		4
Revised transaction price	$ 32,000,000		$ 32,000,000
Contract with customer, receivable, after allowance for credit loss	30,000,000		30,000,000
Collaboration revenue		10,700,000	0
Deferred revenue	30,000,000	$ 20,200,000	30,000,000
2022 Merck KGaA Agreement | Developmental And Regulatory
Collaboration agreements
Aggregate milestones	200,000,000		200,000,000
2022 Merck KGaA Agreement | Commercial
Collaboration agreements
Aggregate milestones	$ 600,000,000		$ 600,000,000