Goodwill and Other Intangibles (Other Intangible Assets and Capitalized Software) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 211.7	$ 221.3
Less: Accumulated Amortization	110.8	108.7
Net Book Value	100.9	112.6
Computer Software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,511.5	4,337.4
Less: Accumulated Amortization	2,906.4	2,744.5
Net Book Value	$ 1,605.1	$ 1,592.9