Subsequent events (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2022	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Collaboration revenues			$ 26,976	$ 14,463	$ 11,697
Genentech
Subsequent Event [Line Items]
Collaboration revenues			$ 11,969	$ 3,565	$ 5,660
Genentech | Collaboration Program 3 Performance Obligation
Subsequent Event [Line Items]
Collaboration revenues	$ 8,400
Subsequent events | Forecast | Genentech | Collaboration Program 3 Performance Obligation
Subsequent Event [Line Items]
Collaboration revenues		$ 10,400
Revenue recognized		$ 7,400