Loans (Aging Of Past Due Loans) (Details) - USD ($) $ in Thousands		Mar. 31, 2021		Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		$ 13,165		$ 23,652
Loan balance		7,168,745		7,177,785
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		20,938	[1]	26,364	[2]
Impaired Financing Receivable, Recorded Investment, Nonaccrual loans which are current in regards to contractual P&I payments		94,600		92,600
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		7,134,642		7,148,422
Loan balance		7,168,745
Construction Real Estate Commercial [Domain]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		223,318
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		25	[1]	39	[2]
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		223,293		227,524
Loan balance		223,318
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		16		17
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		541,968
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		395	[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		541,557		526,873
Loan balance		541,968
Residential Real Estate - Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		4,491		9,538
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,077,696
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		6,902	[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		1,066,303		1,079,953
Loan balance		1,077,696
Residential Real Estate - HELOC [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		57		805
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		171,388
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		663	[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		170,668		181,060
Loan balance		171,388
Residential Real Estate - Installment [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		71		67
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		7,601
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		68	[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		7,462		8,320
Loan balance		7,601
PPP loans receivable [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		18
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		386,972
Loan balance		386,990
Bank Overdrafts | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,373
Loan balance		2,373
Construction Real Estate Retail
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		114,110
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		114,110
Loan balance		114,110
Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		2,099		82
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,756,921
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		795	[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		1,754,027		1,753,152
Loan balance		1,756,921
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		133		186
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		22,557
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		41		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		22,383		$ 23,282
Loan balance		22,557
PPP loans receivable [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		386,990
GFSC loans
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		241
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		5,225
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		160
GFSC loans | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		4,824
Loan balance		5,225
Check loans
Financing Receivable, Past Due [Line Items]
Accruing loans past due 30-89 days		6
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,109
Check loans | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		2,103
Loan balance		2,109
Bank Overdrafts
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		$ 2,373

[1] 1) Includes an aggregate of $0.8 million of loans past due 90 days or more and accruing. The remaining loans were past due nonaccrual loans.(2) Includes an aggregate of $94.6 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.