LOANS AND ALLOWANCE FOR CREDIT LOSSES - Loans Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 20,964,981	$ 20,269,303
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,949,957	2,688,929
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	210,310	241,552
Indirect automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	10,891	34,257
Mortgage warehouse
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	985,910	818,728
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	449,561	492,668
Premium finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,246,452	946,562
Real estate – construction and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,232,114	2,129,187
Real estate – commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	8,249,981	8,059,754
Real estate – residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 4,629,805	$ 4,857,666