LOANS AND ALLOWANCE FOR LOAN LOSSES - Loans Accounted for on a NonAccrual Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 17,952	$ 14,202
Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	24,107	15,428
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,412	1,306
Commercial, financial and agricultural | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,199	813
Real estate – construction and development | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	892	554
Real estate – construction and development | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	6,119	3,139
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	4,654	2,665
Real estate – commercial and farmland | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	5,534	5,685
Real estate – residential | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	10,465	9,194
Real estate – residential | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	10,769	5,743
Consumer installment | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	529	483
Consumer installment | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 486	$ 48