Other income, net - Schedule of Components of Other Income (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Interest income and other:
Interest and dividends	$ 5.5	$ 4.8
Securities transactions, net	0.2	0.1
Total	5.7	4.9
Currency transactions, net	5.8	5.4
Insurance recoveries		1.7
Other, net	0.7	1.1
Total	$ 12.2	$ 13.1