LOANS AND ALLOWANCE FOR CREDIT LOSSES - Analysis of Past-Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Total Loans	$ 20,992,603	$ 20,269,303
Loans 90 Days or More Past Due and Still Accruing	15,909	16,988
Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	284,187	272,839
Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	82,299	82,850
Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	32,491	34,281
Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	169,397	155,708
Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	20,708,416	19,996,464
Commercial, financial and agricultural
Financing Receivable, Past Due [Line Items]
Total Loans	2,860,973	2,688,929
Loans 90 Days or More Past Due and Still Accruing	4,160	5,310
Commercial, financial and agricultural | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	24,138	26,195
Commercial, financial and agricultural | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	9,531	11,023
Commercial, financial and agricultural | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	6,182	5,439
Commercial, financial and agricultural | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	8,425	9,733
Commercial, financial and agricultural | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	2,836,835	2,662,734
Consumer
Financing Receivable, Past Due [Line Items]
Total Loans	217,787	241,552
Loans 90 Days or More Past Due and Still Accruing	0	0
Consumer | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	2,028	3,690
Consumer | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,251	2,155
Consumer | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	552	1,037
Consumer | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	225	498
Consumer | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	215,759	237,862
Indirect automobile
Financing Receivable, Past Due [Line Items]
Total Loans	16,335	34,257
Loans 90 Days or More Past Due and Still Accruing	0	0
Indirect automobile | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	148	248
Indirect automobile | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	70	153
Indirect automobile | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	15	17
Indirect automobile | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	63	78
Indirect automobile | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	16,187	34,009
Mortgage warehouse
Financing Receivable, Past Due [Line Items]
Total Loans	1,070,921	818,728
Loans 90 Days or More Past Due and Still Accruing	0	0
Mortgage warehouse | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Mortgage warehouse | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Mortgage warehouse | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Mortgage warehouse | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Mortgage warehouse | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	1,070,921	818,728
Municipal
Financing Receivable, Past Due [Line Items]
Total Loans	454,967	492,668
Loans 90 Days or More Past Due and Still Accruing	0	0
Municipal | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Municipal | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Municipal | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Municipal | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	0	0
Municipal | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	454,967	492,668
Premium finance
Financing Receivable, Past Due [Line Items]
Total Loans	1,151,261	946,562
Loans 90 Days or More Past Due and Still Accruing	11,416	11,678
Premium finance | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	28,346	30,889
Premium finance | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	8,773	12,379
Premium finance | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	8,158	6,832
Premium finance | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	11,415	11,678
Premium finance | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	1,122,915	915,673
Real estate – construction and development
Financing Receivable, Past Due [Line Items]
Total Loans	2,336,987	2,129,187
Loans 90 Days or More Past Due and Still Accruing	0	0
Real estate – construction and development | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	4,464	2,376
Real estate – construction and development | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	562	2,094
Real estate – construction and development | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	337	0
Real estate – construction and development | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	3,565	282
Real estate – construction and development | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	2,332,523	2,126,811
Real estate – commercial and farmland
Financing Receivable, Past Due [Line Items]
Total Loans	8,103,634	8,059,754
Loans 90 Days or More Past Due and Still Accruing	333	0
Real estate – commercial and farmland | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	11,963	13,078
Real estate – commercial and farmland | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	3,989	5,070
Real estate – commercial and farmland | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	1,999	1,656
Real estate – commercial and farmland | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	5,975	6,352
Real estate – commercial and farmland | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	8,091,671	8,046,676
Real estate – residential
Financing Receivable, Past Due [Line Items]
Total Loans	4,779,738	4,857,666
Loans 90 Days or More Past Due and Still Accruing	0	0
Real estate – residential | Total Loans Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	213,100	196,363
Real estate – residential | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	58,123	49,976
Real estate – residential | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	15,248	19,300
Real estate – residential | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans	139,729	127,087
Real estate – residential | Current Loans
Financing Receivable, Past Due [Line Items]
Total Loans	$ 4,566,638	$ 4,661,303