Goodwill and Other Intangibles (Goodwill by Reporting Segment) (Details) $ in Millions	9 Months Ended
Sep. 30, 2021 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 707.2
Goodwill Acquired	4.2
Foreign Exchange Rates	(5.9)
Goodwill, Ending Balance	705.5
CORPORATE & INSTITUTIONAL SERVICES
Goodwill [Roll Forward]
Goodwill, Beginning Balance	636.0
Goodwill Acquired	4.2
Foreign Exchange Rates	(5.8)
Goodwill, Ending Balance	634.4
WEALTH MANAGEMENT
Goodwill [Roll Forward]
Goodwill, Beginning Balance	71.2
Goodwill Acquired	0.0
Foreign Exchange Rates	(0.1)
Goodwill, Ending Balance	$ 71.1

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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