Loans And The Allowance For Loan Losses (Narrative) (Details) $ in Millions		3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance	$ 0.9	$ 0.9		$ 0.9
Acquired credit-impaired loans	0.8	0.8		0.8		$ 0.0
Valuation allowances, acquired credit-impaired loans	0.0	0.0		0.0
Hotel loan portfolio	81.0	81.0		$ 81.0
Total percentage of hotel loan in total commercial loans				6.50%
Total criticized assets increase	$ 133.0	$ 133.0		$ 133.0		51.0
Period of timely payments before reversion to accruing status				6 months
FSB [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans				$ 271.0
PPP Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fixed rate	1.00%	1.00%		1.00%
Deferred payment period				10 months
Number of PPP loans | loan				1,931
Paycheck Protection Program Loans, total				$ 203.0
Fees	$ 5.8			$ 7.4
PPP Loans [Member] | Before June 5, 2020 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term				2 years
PPP Loans [Member] | On Or After June 5, 2020 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term				5 years
Residential Mortgages [Member] | FSB [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan servicing portfolio principal balance	107.0	$ 107.0		$ 107.0
Commercial And Industrial [Member] | CARES Act [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan				381
Principal balances on loan modification				$ 368.0
Consumer And Other Loans [Member] | CARES Act [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan				298
Principal balances on loan modification				$ 37.0
Total Real Estate Loans [Member] | Residential Mortgages [Member] | Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan servicing portfolio principal balance	185.0	185.0		185.0		76.0
Mortgage servicing rights	1.0	1.0		1.0		0.6
Mortgage loans held-for-sale	$ 0.0	0.0		0.0		$ 0.7
Total Real Estate Loans [Member] | Residential Mortgages [Member] | FHLMC Loans [Member] | Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans sold		0.0	$ 0.0	0.0	$ 0.0
Total Real Estate Loans [Member] | Residential Mortgages [Member] | FNMA Loans [Member] | Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans sold		$ 7.2	$ 3.0	$ 15.0	$ 7.6