Loans Aging of recorded investment in past due loans (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	$ 13,465	$ 23,652
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	21,070	26,364
Loans and Leases Receivable, Recorded Investment		7,198,438
Financing Receivable, 90 Days or More Past Due, Still Accruing	1,607	1,594
Financing Receivable, before Allowance for Credit Loss	6,871,122	7,177,785
impaired financing receivable recorded investment nonaccrual loans which are current in contractual P and I payments	53,300	92,600
Loan and Leases Receivable, Recorded Investment		7,198,438
Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	34,535	50,016
Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	6,836,587	7,148,422
Commercial Financial And Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due		7,372
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		13,968
Loans and Leases Receivable, Recorded Investment		1,595,517
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Loan and Leases Receivable, Recorded Investment		1,595,517
Commercial Financial And Agricultural [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		21,340
Commercial Financial And Agricultural [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,574,177
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due		82
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		972
Loans and Leases Receivable, Recorded Investment		1,754,206
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	377
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,801,792
Loan and Leases Receivable, Recorded Investment		1,754,206
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,054
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,753,152
Construction Real Estate Remaining Commercial [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	0	0
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	0	39
Loans and Leases Receivable, Recorded Investment		227,563
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	214,561
Financing Receivable, before Allowance for Credit Loss	214,561
Loan and Leases Receivable, Recorded Investment		227,563
Construction Real Estate Remaining Commercial [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0	39
Construction Real Estate Remaining Commercial [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	214,561	227,524
Construction Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due		77
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		0
Financing Receivable, 90 Days or More Past Due, Still Accruing		0
Loan and Leases Receivable, Recorded Investment		115,724
Construction Real Estate Mortgage [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		77
Construction Real Estate Mortgage [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		115,647
Construction Real Estate Installment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due		12
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		0
Loan and Leases Receivable, Recorded Investment		941
Construction Real Estate Installment [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		12
Construction Real Estate Installment [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		929
Residential Real Estate Commercial [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	283	17
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	438	493
Loans and Leases Receivable, Recorded Investment		527,383
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	533,802
Financing Receivable, before Allowance for Credit Loss	533,802
Loan and Leases Receivable, Recorded Investment		527,383
Residential Real Estate Commercial [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	721	510
Residential Real Estate Commercial [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	533,081	526,873
Residential Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	6,170	9,538
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	5,933	7,814
Loans and Leases Receivable, Recorded Investment		1,097,305
Financing Receivable, 90 Days or More Past Due, Still Accruing	372	416
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,033,658
Financing Receivable, before Allowance for Credit Loss	1,033,658
Loan and Leases Receivable, Recorded Investment		1,097,305
Residential Real Estate Mortgage [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	12,103	17,352
Residential Real Estate Mortgage [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,021,555	1,079,953
Residential Real Estate Home Equity Line Of Credit [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	565	805
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	1,011	810
Loans and Leases Receivable, Recorded Investment		182,675
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	77
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	165,605
Financing Receivable, before Allowance for Credit Loss	165,605
Loan and Leases Receivable, Recorded Investment		182,675
Residential Real Estate Home Equity Line Of Credit [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,576	1,615
Residential Real Estate Home Equity Line Of Credit [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	164,029	181,060
Residential Real Estate Installment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	49	67
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	31	71
Loans and Leases Receivable, Recorded Investment		8,458
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	5,642
Financing Receivable, before Allowance for Credit Loss	5,642
Loan and Leases Receivable, Recorded Investment		8,458
Residential Real Estate Installment [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	80	138
Residential Real Estate Installment [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	5,562	8,320
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due		5,496
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans		1,213
Loans and Leases Receivable, Recorded Investment		1,664,214
Financing Receivable, 90 Days or More Past Due, Still Accruing	431	724
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	3,002,936
Loan and Leases Receivable, Recorded Investment		1,664,214
Consumer Portfolio Segment [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		6,709
Consumer Portfolio Segment [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,657,505
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	60	186
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	526	984
Loans and Leases Receivable, Recorded Investment		24,452
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	20,532
Financing Receivable, before Allowance for Credit Loss	20,532
Loan and Leases Receivable, Recorded Investment		24,452
Finance Leases Portfolio Segment [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	586	1,170
Finance Leases Portfolio Segment [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	19,946	23,282
commercial financial agricultural less PPP and overdraft
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	2,908
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	9,547
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,223,079
Financing Receivable, before Allowance for Credit Loss	1,223,079
commercial financial agricultural less PPP and overdraft | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	12,455
commercial financial agricultural less PPP and overdraft | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,210,624
PPP Loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	242
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	793
Financing Receivable, 90 Days or More Past Due, Still Accruing	793
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	74,420
Financing Receivable, before Allowance for Credit Loss	74,420
PPP Loans | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,035
PPP Loans | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	73,385
Bank Overdrafts
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	0
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,127
Financing Receivable, before Allowance for Credit Loss	1,127
Bank Overdrafts | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0
Bank Overdrafts | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,127
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	65
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	1,461
Financing Receivable, before Allowance for Credit Loss	1,801,792
Commercial Real Estate [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,526
Commercial Real Estate [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,800,266
Construction Real Estate Retail
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	346
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	660
Loans and Leases Receivable, Recorded Investment		$ 116,665
Financing Receivable, 90 Days or More Past Due, Still Accruing	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	107,225
Financing Receivable, before Allowance for Credit Loss	107,225
Construction Real Estate Retail | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,006
Construction Real Estate Retail | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	106,219
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	2,614
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	618
Financing Receivable, before Allowance for Credit Loss	1,685,793
Consumer Loan [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	3,232
Consumer Loan [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,682,561
GFSC loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	153
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	52
Financing Receivable, 90 Days or More Past Due, Still Accruing	11
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,793
Financing Receivable, before Allowance for Credit Loss	1,793
GFSC loans | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	205
GFSC loans | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,588
Check Loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	10
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	2,093
Financing Receivable, before Allowance for Credit Loss	2,093
Check Loans | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	10
Check Loans | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	$ 2,083