Goodwill and Other Intangibles - Other Intangible Assets and Capitalized Software (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Other Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 135.0	$ 197.9
Less: Accumulated Amortization	63.4	120.3
Net Book Value	71.6	77.6
Computer Software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,781.7	3,479.3
Less: Accumulated Amortization	1,754.2	1,517.4
Net Book Value	$ 2,027.5	$ 1,961.9