Segment Information (Identifiable Assets by Business Segment) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Identifiable assets	$ 13,600.9	$ 14,254.3
Identifiable assets	101.0	107.1
Property and Casualty [Member]
Segment Reporting Information [Line Items]
Identifiable assets	13,499.9	14,147.2
Assets of Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Identifiable assets	$ 101.0	$ 107.1

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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+ Details