Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Currently payable
Federal	[1]	$ 0.0	$ 0.0	$ 0.1
International	[2]	112.2	79.8	70.3
Total current taxes		112.2	79.8	70.4
Deferred
International	[2]	(44.8)	(9.0)	4.6
Total deferred taxes		(44.8)	(9.0)	4.6
Total provision (benefit) for income taxes		$ 67.4	$ 70.8	$ 75.0

[1] “Federal” represents U.K. taxes.

[2] “International” represents non-U.K. taxes.