LOANS - Purchased Loans (Details) - Purchased Loans - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 2,472,271	$ 2,588,832
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	327,972	372,686
Real estate – construction and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	239,413	227,900
Real estate – commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,280,515	1,337,859
Real estate – residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	597,735	623,199
Consumer installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 26,636	$ 27,188