Loans Aging of recorded investment in past due loans (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	$ 17,595	$ 13,465
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	22,085	21,070
Financing Receivable, 90 Days or More Past Due, Still Accruing	1,281	1,607
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	7,141,891	6,871,122	$ 7,177,785
impaired financing receivable recorded investment nonaccrual loans which are current in contractual P and I payments	58,900	53,300
Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	39,680	34,535
Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	7,102,211	6,836,587
Commercial Financial And Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Commercial Real Estate Portfolio Segment [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, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,794,054	1,801,792
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		1,526
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		1,800,266
Construction Real Estate Remaining Commercial [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	751	0
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	0	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	208,982	214,561
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	751	0
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	208,231	214,561
Construction Real Estate Mortgage [Member]
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
Financing Receivable, 90 Days or More Past Due, Still Accruing		0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		107,225
Construction Real Estate Mortgage [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss		1,006
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		106,219
Residential Real Estate Commercial [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	519	283
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	477	438
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	550,183	533,802
Residential Real Estate Commercial [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	996	721
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	549,187	533,081
Residential Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	7,630	6,170
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	5,157	5,933
Financing Receivable, 90 Days or More Past Due, Still Accruing	182	372
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,075,446	1,033,658
Residential Real Estate Mortgage [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	12,787	12,103
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	1,062,659	1,021,555
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	832	565
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	587	1,011
Financing Receivable, 90 Days or More Past Due, Still Accruing	7	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	167,151	165,605
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	1,419	1,576
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	165,732	164,029
Residential Real Estate Installment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	57	49
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	4	31
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	4,091	5,642
Residential Real Estate Installment [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	61	80
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	4,030	5,562
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	703	431
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	3,269,591
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	0	60
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	0	526
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	19,637	20,532
Finance Leases Portfolio Segment [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0	586
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	19,637	19,946
commercial financial agricultural less PPP and overdraft
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	378	2,908
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	9,246	9,547
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,295,238	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	9,624	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	1,285,614	1,210,624
PPP Loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	155	242
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	389	793
Financing Receivable, 90 Days or More Past Due, Still Accruing	389	793
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	4,206	74,420
PPP Loans | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	544	1,035
PPP Loans | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	3,662	73,385
Bank Overdrafts
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	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,489	1,127
Bank Overdrafts | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	0	0
Bank Overdrafts | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,489	1,127
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	737
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	4,738
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,794,054
Commercial Real Estate [Member] | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	5,475
Commercial Real Estate [Member] | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,788,579
Construction Real Estate Retail
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	1,035
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	523
Financing Receivable, 90 Days or More Past Due, Still Accruing	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	116,433
Construction Real Estate Retail | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,558
Construction Real Estate Retail | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	114,875
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	5,451	2,614
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	964	618
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	1,902,557	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	6,415	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	1,896,142	1,682,561
GFSC loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	48	153
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	0	52
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	11
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	274	1,793
GFSC loans | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	48	205
GFSC loans | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	226	1,588
Check Loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Accruing Loans 30 to 89 Days Past Due	2	10
Financing Receivable Recorded Investment Ninety Days Or More Past Due And Accruing Plus Past Due Nonaccrual Loans	0	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	2,150	2,093
Check Loans | Financial Asset, Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	2	10
Check Loans | Financial Asset, Not Past Due
Financing Receivable, Impaired [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss	$ 2,148	$ 2,083