Collaboration agreements - Merck Immunosythen Agreement (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2022 USD ($) performanceObligation target license	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Collaboration agreements
Collaboration revenue		$ 9,245	$ 7,802
Deferred revenue	$ 147,653	117,640	144,351	$ 125,314
2022 Merck Research Collaboration & License Agreement
Collaboration agreements
Number of targets designated | target	2
Upfront payment received	$ 30,000
Number of licenses | license	2
Performance obligations identified | performanceObligation	4
Collaboration revenue		3,200	$ 3,100
Deferred revenue		$ 17,100		$ 20,200