Loans and Leases (Troubled Debt Restructurings) (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020 USD ($) contract	Jun. 30, 2019 USD ($) contract	Jun. 30, 2020 USD ($) contract	Jun. 30, 2019 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES \| contract	0	15	8	29
RECORDED INVESTMENT	$ 0.0	$ 7.7	$ 25.3	$ 25.1
UNPAID PRINCIPAL BALANCE	$ 0.0	$ 7.8	$ 25.7	$ 26.5
COMMERCIAL
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES \| contract	0	2	2	3
RECORDED INVESTMENT	$ 0.0	$ 0.0	$ 24.3	$ 7.6
UNPAID PRINCIPAL BALANCE	$ 0.0	$ 0.0	$ 24.5	$ 8.8
COMMERCIAL \| Commercial and Institutional
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES \| contract	0	0	2	1
RECORDED INVESTMENT	$ 0.0	$ 0.0	$ 24.3	$ 7.6
UNPAID PRINCIPAL BALANCE	$ 0.0	$ 0.0	$ 24.5	$ 8.8
COMMERCIAL \| Commercial Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES \| contract		2		2
RECORDED INVESTMENT		$ 0.0		$ 0.0
UNPAID PRINCIPAL BALANCE		$ 0.0		$ 0.0
Personal
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES \| contract	0	13	6	26
RECORDED INVESTMENT	$ 0.0	$ 7.7	$ 1.0	$ 17.5
UNPAID PRINCIPAL BALANCE	$ 0.0	$ 7.8	$ 1.2	$ 17.7
Personal \| Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES \| contract	0	13	6	26
RECORDED INVESTMENT	$ 0.0	$ 7.7	$ 1.0	$ 17.5
UNPAID PRINCIPAL BALANCE	$ 0.0	$ 7.8	$ 1.2	$ 17.7

Financing Receivable, Troubled Debt Restructuring, Postmodification, Unpaid Principal Balance

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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

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

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