Goodwill and Other Intangibles (Goodwill by Reporting Segment) (Details) $ in Millions	6 Months Ended
Jun. 30, 2021 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 707.2
Goodwill Acquired	0.0
Foreign Exchange Rates	(2.0)
Goodwill, Ending Balance	709.4
CORPORATE & INSTITUTIONAL SERVICES
Goodwill [Roll Forward]
Goodwill, Beginning Balance	636.0
Goodwill Acquired	4.2
Foreign Exchange Rates	(2.0)
Goodwill, Ending Balance	638.2
WEALTH MANAGEMENT
Goodwill [Roll Forward]
Goodwill, Beginning Balance	71.2
Foreign Exchange Rates	0.0
Goodwill, Ending Balance	$ 71.2

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 increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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