LOANS - Loans Accounted for on a Nonaccrual Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 14,420	$ 14,202
Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	15,940	15,428
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,548	1,306
Commercial, financial and agricultural | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	796	813
Real estate – construction and development | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	518	554
Real estate – construction and development | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	3,112	3,139
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	3,555	2,665
Real estate – commercial and farmland | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	4,347	5,685
Real estate – residential | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	8,311	9,194
Real estate – residential | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	7,648	5,743
Consumer installment | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	488	483
Consumer installment | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 37	$ 48