Commitments and contingencies - Others (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Commitments and contingencies
Non-cancellable obligations	$ 9.3
2023 deliverables	9.2
2024 deliverables	0.1
Licensing fees from intellectual property licenses	$ 1.0	$ 1.3	$ 1.2