LOANS - Loans Receivable, Excluding Purchased Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 9,049,870	$ 8,511,914
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	6,522,448	5,660,457
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	1,648,190	1,316,359
Real estate – construction and development | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	788,409	671,198
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,046,347	1,814,529
Real estate – residential | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	1,589,646	1,403,000
Consumer installment | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 449,856	$ 455,371