Goodwill and Other Assets (Textuals) (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended		7 Months Ended	9 Months Ended
	Aug. 11, 2023	Sep. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Aug. 11, 2023	Sep. 30, 2022	Aug. 12, 2023	Dec. 31, 2022
Goodwill [Line Items]
Amortization	$ 11.0	$ 15.6		$ 23.2	$ 59.0	$ 72.1
Goodwill		596.7	$ 596.7				$ 621.0	$ 702.3
Global Retail [Member]
Goodwill [Line Items]
Goodwill		139.3	$ 139.3				149.6	212.4
Segment Reporting, Additional Information about Entity's Reportable Segments			34 percent
Global Banking
Goodwill [Line Items]
Goodwill		$ 457.4	$ 457.4				$ 471.4	$ 489.9
Segment Reporting, Additional Information about Entity's Reportable Segments			43 percent