Goodwill and Other Intangibles (Goodwill by Reporting Segment) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 691.3
Foreign Exchange Rates	7.5
Goodwill, Ending Balance	698.8
ASSET SERVICING
Goodwill [Roll Forward]
Goodwill, Beginning Balance	611.0
Foreign Exchange Rates	7.4
Goodwill, Ending Balance	618.4
WEALTH MANAGEMENT
Goodwill [Roll Forward]
Goodwill, Beginning Balance	80.3
Foreign Exchange Rates	0.1
Goodwill, Ending Balance	$ 80.4