Property, plant and equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, plant and equipment
Depreciation expense	$ 3.0	$ 3.2	$ 3.4
Cost of sales
Property, plant and equipment
Depreciation expense	$ 2.0	$ 2.0	$ 1.9