Collaboration agreements - Merck Immunosythen Agreement (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) target performanceObligation	Dec. 31, 2021 USD ($)
Collaboration agreements
Collaboration revenue		$ 10,654	$ 4,284	$ 18,456	$ 6,320
Deferred revenue		134,697	$ 37,914	134,697	$ 37,914	$ 147,653	$ 3,944
2022 Merck Research Collaboration & License Agreement
Collaboration agreements
Number of targets designated | target						2
Upfront payment received	$ 30,000
Performance obligations identified | performanceObligation						4
Collaboration revenue		2,500		5,600
Deferred revenue		$ 25,400		$ 25,400		$ 30,000