Collaboration agreements - Johnson & Johnson (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 28, 2022 USD ($) target performanceObligation	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Collaboration agreements
Collaboration revenue		$ 9,245	$ 7,802
Deferred revenue		117,640	144,351	$ 125,314	$ 147,653
Johnson & Johnson Agreement
Collaboration agreements
Number of targets designated | target	3
Upfront payment received	$ 40,000
Performance obligations identified | performanceObligation	7
Revised transaction price		48,000
Collaboration revenue		6,100	$ 1,500
Johnson and Johnson 2024 CMC Arrangement
Collaboration agreements
Revised transaction price		5,000
Johnson and Johnson Agreement and Johnson and Johnson 2024 CMC Arrangement
Collaboration agreements
Deferred revenue		$ 5,700		$ 10,400