Goodwill and Other Intangible Assets - Other Intangible Assets, Changes in Net Carrying Amount (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Gross Amount
Other intangible assets, beginning	$ 604.4	$ 618.7
Finite-Lived Intangible Assets, Disposal of Intangible Assets	(0.5)	(13.4)
Currency translation effect on foreign balances	0.4	(0.9)
Other intangible assets, ending	609.2	604.4	$ 618.7
Finite-Lived Intangible Assets Acquired	4.9	0.0
Accumulated Amortization
Other intangible assets, beginning	(80.0)	(74.8)
Amortization of Intangible Assets, Adjustment for Disposal	0.5	13.4
Amortization expense	(17.7)	(18.8)	(22.9)
Currency translation effect on foreign balances	0.0	0.2
Other intangible assets, ending	$ (97.2)	$ (80.0)	$ (74.8)