Acquisition (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Jul. 13, 2018
Business Acquisition [Line Items]
Useful life	17 years
Acquisition related costs	$ 0.3
Capital One [Member]
Business Acquisition [Line Items]
Assets under management		$ 4,000.0
Assets under management and administration		10,400.0
Cash for customer deposit liabilities assumed		$ 217.0
Trust And Asset Management Acquisition [Member]
Business Acquisition [Line Items]
Trust fee revenue	4.9
Related expense	$ 4.8

Business Acquisition, Related expense

No definition available.

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- Definition

Business Acquisition, Trust Fee Revenue

+ References

No definition available.

+ Details

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- Definition

Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Cash For Customer Deposit Liabilities Assumed

+ References

No definition available.

+ Details

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- Definition

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Assets Under Management And Administration

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e1043-128460

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

The amount of financial assets (as defined) recognized as of the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 55
-Paragraph 37
-URI http://asc.fasb.org/extlink&oid=84160947&loc=d3e2207-128464

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-URI http://asc.fasb.org/topic&trid=2134543

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Details

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- Details

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