Income taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Provision for income taxes (in millions)	$ 8.5	$ 22.9	$ (3.3)	$ 59.2
Effective tax rate	27.30%	49.90%	(2.50%)	47.50%