LOANS - Loans Accounted for on a Nonaccrual Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 77,745	$ 75,124
Financing receivable, nonaccrual, no allowance	21,080
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	11,032	9,236
Financing receivable, nonaccrual, no allowance	1,081
Consumer installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,186	831
Indirect automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,643	1,746
Premium finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	0	600
Real estate – construction and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,913	1,988
Real estate – commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	21,874	23,797
Financing receivable, nonaccrual, no allowance	9,632
Real estate – residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	40,097	$ 36,926
Financing receivable, nonaccrual, no allowance	$ 10,367