Loans (Aging Of Past Due Loans) (Details) - USD ($) $ in Thousands		Sep. 30, 2021		Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		$ 14,376		$ 23,652
Loan balance		6,908,417		7,177,785
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		20,354	[1]	26,364	[2]
Impaired Financing Receivable, Recorded Investment, Nonaccrual loans which are current in regards to contractual P&I payments		67,700		92,600
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		6,873,687		7,148,422
Construction Real Estate Commercial [Domain]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		815
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		231,210
Loan balance		231,210
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	[2]			39
Construction Real Estate Commercial [Domain] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		230,395		227,524
Commercial Financial And Agricultural [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days				7,372
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	[2]			13,968
Commercial Financial And Agricultural [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss				1,574,177
Construction Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days				77
Construction Real Estate - Mortgage [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss				115,647
Construction Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days				12
Construction Real Estate - Installment [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss				929
Residential Real Estate Commercial [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days				17
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		527,151
Loan balance		527,151
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		413	[1]	493	[2]
Residential Real Estate Commercial [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		526,738		526,873
Residential Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		5,931		9,538
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,052,093
Loan balance		1,052,093
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		5,884	[1]	7,814	[2]
Residential Real Estate - Mortgage [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,040,278		1,079,953
Residential Real Estate - HELOC [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		487		805
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		166,454
Loan balance		166,454
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		997	[1]	810	[2]
Residential Real Estate - HELOC [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		164,970		181,060
Residential Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		37		67
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		6,410
Loan balance		6,410
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		93	[1]	71	[2]
Residential Real Estate - Installment [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		6,280		8,320
PPP loans receivable [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		1
Loan balance		131,483
PPP loans receivable [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		131,482
Bank Overdrafts
Financing Receivable, Past Due [Line Items]
Loan balance		4,033
Bank Overdrafts | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		4,033
Construction Real Estate Retail
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		1,202
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		111,677
Loan balance		111,677
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		12
Construction Real Estate Retail | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		110,463
Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days				82
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,761,596
Loan balance		1,761,596
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		1,009	[1]	972	[2]
Commercial Real Estate [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,760,587		1,753,152
Consumer [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days				5,496
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	[2]			1,213
Consumer [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss				1,657,505
Finance Leases Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		53		186
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		21,632
Loan balance		21,632
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		576		984	[2]
Finance Leases Portfolio Segment [Member] | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		21,003		$ 23,282
PPP loans receivable [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		131,483
GFSC loans
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		196
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,624
Loan balance		2,624
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		57
GFSC loans | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,371
Check loans
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		8
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,092
Loan balance		2,092
Check loans | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,084
Bank Overdrafts
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		$ 4,033

[1] 1) Includes an aggregate of $0.3 million of loans past due 90 days or more and accruing. The remaining loans were past due nonaccrual loans.(2) Includes an aggregate of $67.7 million of nonaccrual loans which were current in regards to contractual principal and interest payments

[2] 1) Includes an aggregate of $1.6 million of loans past due 90 days or more and accruing. The remaining loans were past due nonaccrual loans.(2) Includes an aggregate of $92.6 million of nonaccrual loans which were current in regards to contractual principal and interest payments.