LOANS AND ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	$ 172,642	$ 175,070	$ 167,582	$ 199,422
Provision for loan losses	17,469	(3,984)	27,962	(21,462)
Loans charged off	(9,272)	(3,537)	(24,704)	(18,249)
Recoveries of loans previously charged off	4,052	3,664	14,051	11,502
Ending balance, Allowance	184,891	171,213	184,891	171,213
Commercial, financial and agricultural
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	25,658	6,889	26,829	7,359
Provision for loan losses	9,568	(1,471)	11,521	2,606
Loans charged off	(4,722)	(858)	(13,527)	(6,757)
Recoveries of loans previously charged off	2,201	1,986	7,882	3,338
Ending balance, Allowance	32,705	6,546	32,705	6,546
Consumer installment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	5,269	7,824	6,097	4,076
Provision for loan losses	(244)	3,063	1,102	9,360
Loans charged off	(1,228)	(1,647)	(3,790)	(4,764)
Recoveries of loans previously charged off	277	199	665	767
Ending balance, Allowance	4,074	9,439	4,074	9,439
Indirect automobile
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	291	1,080	476	1,929
Provision for loan losses	(288)	(268)	(884)	(1,219)
Loans charged off	(50)	(178)	(179)	(1,148)
Recoveries of loans previously charged off	276	278	816	1,350
Ending balance, Allowance	229	912	229	912
Mortgage warehouse
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	3,885	3,365	3,231	3,666
Provision for loan losses	(1,884)	(287)	(1,230)	(588)
Loans charged off	0	0	0	0
Recoveries of loans previously charged off	0	0	0	0
Ending balance, Allowance	2,001	3,078	2,001	3,078
Municipal
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	371	777	401	791
Provision for loan losses	(9)	(27)	(39)	(41)
Loans charged off	0	0	0	0
Recoveries of loans previously charged off	0	0	0	0
Ending balance, Allowance	362	750	362	750
Premium finance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	2,762	4,539	2,729	3,879
Provision for loan losses	(638)	(456)	(530)	(847)
Loans charged off	(1,205)	(605)	(3,640)	(3,142)
Recoveries of loans previously charged off	1,023	649	3,383	4,237
Ending balance, Allowance	1,942	4,127	1,942	4,127
Real estate – construction and development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	23,232	18,999	22,045	45,304
Provision for loan losses	3,227	(6,423)	3,841	(32,767)
Loans charged off	0	0	0	(212)
Recoveries of loans previously charged off	96	45	669	296
Ending balance, Allowance	26,555	12,621	26,555	12,621
Real estate – commercial and farmland
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	59,349	88,338	77,831	88,894
Provision for loan losses	(1,200)	87	(18,399)	727
Loans charged off	(2,014)	(210)	(3,378)	(1,632)
Recoveries of loans previously charged off	96	266	177	492
Ending balance, Allowance	56,231	88,481	56,231	88,481
Real estate – residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	51,825	43,259	27,943	43,524
Provision for loan losses	8,937	1,798	32,580	1,307
Loans charged off	(53)	(39)	(190)	(594)
Recoveries of loans previously charged off	83	241	459	1,022
Ending balance, Allowance	$ 60,792	$ 45,259	$ 60,792	$ 45,259