Collaboration agreements - Merck Immunosythen Agreement (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Dec. 31, 2022 USD ($) target license performanceObligation	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Collaboration agreements
Collaboration revenue		$ 2,293	$ 10,654	$ 11,538	$ 18,456
Deferred revenue	$ 147,653	116,916	134,697	116,916	134,697	$ 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		0	$ 2,500	3,200	$ 5,600
Deferred revenue		$ 17,000		$ 17,000		$ 20,200