Loans - Schedule of recorded investment in nonaccrual restructured and loans 90 days past due and accruing (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	$ 72,722	$ 117,368
Financing Receivable, Troubled Debt Restructuring	28,323	20,888
Financing Receivable, 90 Days or More Past Due, Still Accruing	1,607	1,594
Financing Receivable Recorded Investment Nonperforming	102,652	139,850
Commercial Financial And Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	13,271	23,261
Financing Receivable, Troubled Debt Restructuring	9,396	5,619
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable Recorded Investment Nonperforming	22,667	28,880
PPP Loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	0
Financing Receivable, Troubled Debt Restructuring	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	793
Financing Receivable Recorded Investment Nonperforming	793
Bank Overdrafts
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	0
Financing Receivable, Troubled Debt Restructuring	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0
Financing Receivable Recorded Investment Nonperforming	0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	40,142	67,426
Financing Receivable, Troubled Debt Restructuring	7,713	2,931
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	377
Financing Receivable Recorded Investment Nonperforming	47,855	70,734
Construction Real Estate Remaining Commercial [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	52	3,110
Financing Receivable, Troubled Debt Restructuring	169	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable Recorded Investment Nonperforming	221	3,110
Construction Real Estate Retail
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	716
Financing Receivable, Troubled Debt Restructuring	9
Financing Receivable, 90 Days or More Past Due, Still Accruing	0
Financing Receivable Recorded Investment Nonperforming	725
Construction Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual		14
Financing Receivable, Troubled Debt Restructuring		31
Financing Receivable, 90 Days or More Past Due, Still Accruing		0
Financing Receivable Recorded Investment Nonperforming		45
Residential Real Estate Commercial [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	2,366	4,304
Financing Receivable, Troubled Debt Restructuring	240	253
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable Recorded Investment Nonperforming	2,606
Residential Real Estate Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	11,718	14,016
Financing Receivable, Troubled Debt Restructuring	7,779	8,400
Financing Receivable, 90 Days or More Past Due, Still Accruing	372	416
Financing Receivable Recorded Investment Nonperforming	19,869	22,832
Residential Real Estate Home Equity Line Of Credit [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	1,590	1,286
Financing Receivable, Troubled Debt Restructuring	803	909
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	77
Financing Receivable Recorded Investment Nonperforming	2,393	2,272
Residential Real Estate Installment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	82	184
Financing Receivable, Troubled Debt Restructuring	1,508	1,728
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable Recorded Investment Nonperforming	1,590	1,912
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	1,518	2,172
Financing Receivable, Troubled Debt Restructuring	700	1,017
Financing Receivable, 90 Days or More Past Due, Still Accruing	431	724
Financing Receivable Recorded Investment Nonperforming	2,649	3,913
GFSC loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	79
Financing Receivable, Troubled Debt Restructuring	6
Financing Receivable, 90 Days or More Past Due, Still Accruing	11
Financing Receivable Recorded Investment Nonperforming	96
Check Loans
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	0
Financing Receivable, Troubled Debt Restructuring	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0
Financing Receivable Recorded Investment Nonperforming	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Nonaccrual	1,188	1,595
Financing Receivable, Troubled Debt Restructuring	0	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable Recorded Investment Nonperforming	$ 1,188	$ 1,595