Goodwill and Other Intangibles (Goodwill by Reporting Segment) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 691.3
Foreign Exchange Rates	3.8
Goodwill, Ending Balance	695.1
ASSET SERVICING
Goodwill [Roll Forward]
Goodwill, Beginning Balance	611.0
Foreign Exchange Rates	3.8
Goodwill, Ending Balance	614.8
WEALTH MANAGEMENT
Goodwill [Roll Forward]
Goodwill, Beginning Balance	80.3
Foreign Exchange Rates	0.0
Goodwill, Ending Balance	$ 80.3