Income Taxes - Income (Loss) Before Income Taxes and Noncontrolling Interest (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Federal	[1]	$ (9.9)	$ (10.1)	$ (11.2)
International	[2]	628.8	560.7	638.0
Income from continuing operations before income taxes		$ 618.9	$ 550.6	$ 626.8
Federal statutory income tax rate	[3]	23.50%	19.00%	19.00%

[1] “Federal” reflects United Kingdom (“U.K.”) loss from continuing operations before income taxes, given U.K. tax residency.

[2] “International” reflects non-U.K. income from continuing operations before income taxes.

[3] The U.K. Finance Act of 2021 increased the statutory tax rate from 19.0% to 25.0%, effective April 1, 2023. Given this change, a prorated U.K. federal statutory income tax rate was utilized for 2023.