Goodwill and Other Intangibles (Other Intangible Assets Subject to Amortization and Capitalized Software) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Other Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 125.5		$ 127.0
Less: Accumulated Amortization	67.3		68.9
Net Book Value	58.2	$ 67.0	58.1
Finite-Lived Intangible Assets [Roll Forward]
Balance	58.1	71.6
Amortization	(2.1)	(2.3)
Foreign Exchange Rates	2.2	(2.3)
Balance	58.2	67.0
Computer Software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,561.0		4,259.6
Less: Accumulated Amortization	2,243.9		2,104.5
Net Book Value	2,317.1		$ 2,155.1
Finite-Lived Intangible Assets [Roll Forward]
Balance	2,155.1
Amortization	(162.9)	$ (140.4)
Balance	$ 2,317.1