Collaboration agreements - Janssen Biotech (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2022 USD ($) target	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	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
Janssen Agreement
Collaboration agreements
Number of targets designated | target	3
Upfront payment received	$ 40,000
Collaboration revenue		7,500	$ 4,300	9,100	$ 6,000
Revised transaction price		44,000		44,000
Transaction price adjustment				2,000
Deferred revenue		$ 8,700		$ 8,700		$ 15,800