Goodwill and Other Intangibles (Other Intangible Assets and Capitalized Software) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Other Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 136.0	$ 135.0
Less: Accumulated Amortization	71.1	63.4
Net Book Value	64.9	71.6
Computer Software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,256.2	3,781.7
Less: Accumulated Amortization	2,197.4	1,754.2
Net Book Value	$ 2,058.8	$ 2,027.5