LOANS AND ALLOWANCE FOR CREDIT LOSSES - Loans Accounted for on a Nonaccrual Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	$ 134,558	$ 134,808
Financing receivable, nonaccrual, no allowance	74,273	60,231
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	7,558	11,094
Financing receivable, nonaccrual, no allowance	677	33
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	888	420
Financing receivable, nonaccrual, no allowance	285	0
Indirect automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	290	346
Real estate – construction and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	282	523
Real estate – commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	8,063	13,203
Financing receivable, nonaccrual, no allowance	4,133	1,464
Real estate – residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	117,477	109,222
Financing receivable, nonaccrual, no allowance	69,178	58,734
Real estate – residential | GNMA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual	$ 80,800	$ 69,600