LOANS AND ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	$ 167,582	$ 199,422
Provision for loan losses	(2,734)	(16,579)
Loans charged off	(8,579)	(7,574)
Recoveries of loans previously charged off	4,982	3,301
Ending balance, Allowance	161,251	178,570
Commercial, financial and agricultural
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	26,829	7,359
Provision for loan losses	215	2,575
Loans charged off	(4,414)	(2,370)
Recoveries of loans previously charged off	2,896	727
Ending balance, Allowance	25,526	8,291
Consumer installment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	6,097	4,076
Provision for loan losses	789	5,806
Loans charged off	(1,425)	(1,448)
Recoveries of loans previously charged off	158	356
Ending balance, Allowance	5,619	8,790
Indirect automobile
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	476	1,929
Provision for loan losses	(290)	(528)
Loans charged off	(88)	(829)
Recoveries of loans previously charged off	275	700
Ending balance, Allowance	373	1,272
Mortgage warehouse
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	3,231	3,666
Provision for loan losses	(221)	(145)
Loans charged off	0	0
Recoveries of loans previously charged off	0	0
Ending balance, Allowance	3,010	3,521
Municipal
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	401	791
Provision for loan losses	(17)	(1)
Loans charged off	0	0
Recoveries of loans previously charged off	0	0
Ending balance, Allowance	384	790
Premium finance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	2,729	3,879
Provision for loan losses	(92)	442
Loans charged off	(1,369)	(1,343)
Recoveries of loans previously charged off	1,247	1,122
Ending balance, Allowance	2,515	4,100
Real estate – construction and development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	22,045	45,304
Provision for loan losses	4,568	(22,587)
Loans charged off	0	(26)
Recoveries of loans previously charged off	218	167
Ending balance, Allowance	26,831	22,858
Real estate – commercial and farmland
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	77,831	88,894
Provision for loan losses	(9,552)	3,671
Loans charged off	(1,283)	(1,395)
Recoveries of loans previously charged off	37	41
Ending balance, Allowance	67,033	91,211
Real estate – residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	27,943	43,524
Provision for loan losses	1,866	(5,812)
Loans charged off	0	(163)
Recoveries of loans previously charged off	151	188
Ending balance, Allowance	$ 29,960	$ 37,737

Amount excluding accrued interest, of allowance for credit loss on financing receivable.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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-Publisher FASB
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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Amount of credit loss expense (reversal of expense) for financing receivable.

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