Reporting Segments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Net Interest Income	$ 522.9	$ 511.5	$ 1,051.0	$ 1,042.7
Scenario, Adjustment | Asset Servicing segment
Segment Reporting Information [Line Items]
Net Interest Income	(32.0)		(63.0)
Scenario, Adjustment | Wealth Management segment
Segment Reporting Information [Line Items]
Net Interest Income	$ 32.0		$ 63.0