Loans and Leases (COVID-19 Loan Modifications Not Considered TDRS) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) contract	Dec. 31, 2019 contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	25	48
CARES Act | Active Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	31,000,000
LOAN VOLUME	$ 20.7
DEFERRED PRINCIPAL AMOUNT	0.2
DEFERRED INTEREST AMOUNT	$ 0.2
CARES Act | Completed Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	635,000,000
LOAN VOLUME	$ 1,071.7
DEFERRED PRINCIPAL AMOUNT	1.7
DEFERRED INTEREST AMOUNT	$ 8.7
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	3	3
Commercial | CARES Act | Active Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	2,000,000
LOAN VOLUME	$ 6.7
DEFERRED PRINCIPAL AMOUNT	0.0
DEFERRED INTEREST AMOUNT	$ 0.0
Commercial | CARES Act | Completed Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	196,000,000
LOAN VOLUME	$ 717.1
DEFERRED PRINCIPAL AMOUNT	0.1
DEFERRED INTEREST AMOUNT	$ 5.4
Commercial | Commercial and Institutional
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	3	1
Commercial | Commercial and Institutional | CARES Act | Active Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	1,000,000
LOAN VOLUME	$ 6.0
DEFERRED PRINCIPAL AMOUNT	0.0
DEFERRED INTEREST AMOUNT	$ 0.0
Commercial | Commercial and Institutional | CARES Act | Completed Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	99,000,000
LOAN VOLUME	$ 249.3
DEFERRED PRINCIPAL AMOUNT	0.1
DEFERRED INTEREST AMOUNT	$ 2.2
Commercial | Commercial Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract		2
Commercial | Commercial Real Estate | CARES Act | Active Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	1,000,000
LOAN VOLUME	$ 0.7
DEFERRED PRINCIPAL AMOUNT	0.0
DEFERRED INTEREST AMOUNT	$ 0.0
Commercial | Commercial Real Estate | CARES Act | Completed Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	97,000,000
LOAN VOLUME	$ 467.8
DEFERRED PRINCIPAL AMOUNT	0.0
DEFERRED INTEREST AMOUNT	$ 3.2
Personal
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	22	45
Personal | CARES Act | Active Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	29,000,000
LOAN VOLUME	$ 14.0
DEFERRED PRINCIPAL AMOUNT	0.2
DEFERRED INTEREST AMOUNT	$ 0.2
Personal | CARES Act | Completed Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	439,000,000
LOAN VOLUME	$ 354.6
DEFERRED PRINCIPAL AMOUNT	1.6
DEFERRED INTEREST AMOUNT	$ 3.3
Personal | Private Client | CARES Act | Active Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	8,000,000
LOAN VOLUME	$ 8.9
DEFERRED PRINCIPAL AMOUNT	0.1
DEFERRED INTEREST AMOUNT	$ 0.1
Personal | Private Client | CARES Act | Completed Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	27,000,000
LOAN VOLUME	$ 171.9
DEFERRED PRINCIPAL AMOUNT	0.0
DEFERRED INTEREST AMOUNT	$ 1.1
Personal | Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	22	45
Personal | Residential Real Estate | CARES Act | Active Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	21,000,000
LOAN VOLUME	$ 5.1
DEFERRED PRINCIPAL AMOUNT	0.1
DEFERRED INTEREST AMOUNT	$ 0.1
Personal | Residential Real Estate | CARES Act | Completed Deferral
Financing Receivable, Troubled Debt Restructuring [Line Items]
NUMBER OF LOANS AND LEASES | contract	412,000,000
LOAN VOLUME	$ 182.7
DEFERRED PRINCIPAL AMOUNT	1.6
DEFERRED INTEREST AMOUNT	$ 2.2