Loans (Loan Modifications Made To Borrowers Experiencing Financial Difficulty) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items]
AMORTIZED COST BASIS	$ 0.3	$ 2.9
% OF TOTAL SEGMENT	0.00%	0.05%
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
AMORTIZED COST BASIS	$ 0.0	$ 0.0
% OF TOTAL SEGMENT	0.00%	0.00%
Personal
Financing Receivable, Troubled Debt Restructuring [Line Items]
AMORTIZED COST BASIS	$ 0.3	$ 2.9
% OF TOTAL SEGMENT	0.00%	0.05%
Personal \| Residential Real Estate \| Principal and/or interest deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
AMORTIZED COST BASIS	$ 0.0	$ 2.9
% OF TOTAL SEGMENT	0.00%	0.05%
Financing receivable, modified, weighted average term increase from modification		180 days
Personal \| Residential Real Estate \| Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
AMORTIZED COST BASIS	$ 0.1	$ 0.0
% OF TOTAL SEGMENT	0.00%	0.00%
Financing receivable, modified, weighted average term increase from modification	14 months
Personal \| Private Client \| Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
AMORTIZED COST BASIS	$ 0.2	$ 0.0
% OF TOTAL SEGMENT	0.00%	0.00%
Financing receivable, modified, weighted average term increase from modification	22 months

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

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- Definition

Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables.

+ References

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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
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-Section 55
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-URI https://asc.fasb.org//1943274/2147481933/310-10-55-12A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-33

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-34

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- Definition

Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481933/310-10-55-12A

+ Details

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