Royalty and other revenue - Narrative (Detail) - Royalty and other revenue - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
License And Royalty Revenue [Line Items]
Milestone payment		$ 3,649	$ 6,220	$ 21,076
Juno Therapeutics | Bluebird Bio
License And Royalty Revenue [Line Items]
Milestone payment	$ 2,500