Goodwill and Other Intangible Assets - Other Intangible Assets, Changes in Net Carrying Amount (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Gross Amount
Other intangible assets, beginning		$ 609.2	$ 604.4
Other intangible assets acquired		62.7
Indefinite-Lived Intangible Assets, Period Increase (Decrease)			4.9
Other intangible assets disposed of		(0.1)	(0.5)
Other intangible assets impaired	$ 9.5	(9.5)
Currency translation effect on foreign balances		(0.6)	0.4
Other intangible assets, ending	661.7	661.7	609.2	$ 604.4
Accumulated Amortization
Other intangible assets, beginning		(97.2)	(80.0)
Amortization of Intangible Assets, Adjustment for Disposal		0.1	0.5
Amortization expense		(21.9)	(17.7)	(18.8)
Other intangible assets, ending	$ (119.0)	$ (119.0)	$ (97.2)	$ (80.0)