Income taxes - Schedule of Net Loss From Operations Before Income Taxes (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2023	Oct. 31, 2022	Oct. 31, 2021
Income Tax Disclosure [Abstract]
Canada	$ 4.6	$ (72.0)	$ (46.1)	$ (70.9)
Foreign	(3.0)	(65.9)	(4.2)	0.4
Net (loss) income before taxes	$ 1.6	$ (137.9)	$ (50.3)	$ (70.5)