LOANS - Loans Accounted for on a Nonaccrual Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 17,633	$ 17,952
Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	23,846	24,107
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,349	1,412
Commercial, financial and agricultural | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	3,857	1,199
Real estate – construction and development | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	1,244	892
Real estate – construction and development | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	5,933	6,119
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	3,496	4,654
Real estate – commercial and farmland | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	5,061	5,534
Real estate – residential | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	11,118	10,465
Real estate – residential | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	8,402	10,769
Consumer installment | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	426	529
Consumer installment | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 593	$ 486