LOANS - Analysis of Past-Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Total Loans	$ 9,049,870	$ 8,511,914
Loans Excluding Purchased Loan
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	60,869	53,984
Current Loans	6,461,579	5,606,473
Total Loans	6,522,448	5,660,457
Loans 90 Days or More Past Due and Still Accruing	4,439	4,222
Loans Excluding Purchased Loan | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	28,723	23,089
Loans Excluding Purchased Loan | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	12,825	12,104
Loans Excluding Purchased Loan | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	19,321	18,791
Purchased Loans
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	30,090	35,599
Current Loans	2,256,335	2,553,233
Total Loans	2,286,425	2,588,832
Loans 90 Days or More Past Due and Still Accruing	174	0
Purchased Loans | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	10,308	16,193
Purchased Loans | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	4,744	4,166
Purchased Loans | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	15,038	15,240
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	20,659	16,537
Current Loans	1,627,531	1,299,822
Total Loans	1,648,190	1,316,359
Loans 90 Days or More Past Due and Still Accruing	4,180	3,808
Commercial, financial and agricultural | Loans Excluding Purchased Loan | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	5,645	6,479
Commercial, financial and agricultural | Loans Excluding Purchased Loan | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	8,033	5,295
Commercial, financial and agricultural | Loans Excluding Purchased Loan | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	6,981	4,763
Commercial, financial and agricultural | Purchased Loans
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	2,192	1,852
Current Loans	250,429	370,834
Total Loans	252,621	372,686
Loans 90 Days or More Past Due and Still Accruing	0	0
Commercial, financial and agricultural | Purchased Loans | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	27	421
Commercial, financial and agricultural | Purchased Loans | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	1,670	416
Commercial, financial and agricultural | Purchased Loans | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	495	1,015
Real estate – construction and development | Loans Excluding Purchased Loan
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	7,515	2,424
Current Loans	780,894	668,774
Total Loans	788,409	671,198
Loans 90 Days or More Past Due and Still Accruing	0	0
Real estate – construction and development | Loans Excluding Purchased Loan | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	6,177	1,218
Real estate – construction and development | Loans Excluding Purchased Loan | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	418	481
Real estate – construction and development | Loans Excluding Purchased Loan | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	920	725
Real estate – construction and development | Purchased Loans
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	6,707	6,270
Current Loans	308,434	221,630
Total Loans	315,141	227,900
Loans 90 Days or More Past Due and Still Accruing	0	0
Real estate – construction and development | Purchased Loans | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	40	627
Real estate – construction and development | Purchased Loans | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	2	370
Real estate – construction and development | Purchased Loans | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	6,665	5,273
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	4,069	5,800
Current Loans	2,042,278	1,808,729
Total Loans	2,046,347	1,814,529
Loans 90 Days or More Past Due and Still Accruing	0	0
Real estate – commercial and farmland | Loans Excluding Purchased Loan | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	865	1,625
Real estate – commercial and farmland | Loans Excluding Purchased Loan | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	1,032	530
Real estate – commercial and farmland | Loans Excluding Purchased Loan | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	2,172	3,645
Real estate – commercial and farmland | Purchased Loans
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	6,863	4,369
Current Loans	1,129,003	1,333,490
Total Loans	1,135,866	1,337,859
Loans 90 Days or More Past Due and Still Accruing	1	0
Real estate – commercial and farmland | Purchased Loans | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	2,494	1,935
Real estate – commercial and farmland | Purchased Loans | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	921	736
Real estate – commercial and farmland | Purchased Loans | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	3,448	1,698
Real estate – residential | Loans Excluding Purchased Loan
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	25,285	24,977
Current Loans	1,564,361	1,378,023
Total Loans	1,589,646	1,403,000
Loans 90 Days or More Past Due and Still Accruing	0	0
Real estate – residential | Loans Excluding Purchased Loan | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	14,194	11,423
Real estate – residential | Loans Excluding Purchased Loan | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	2,370	4,631
Real estate – residential | Loans Excluding Purchased Loan | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	8,721	8,923
Real estate – residential | Purchased Loans
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	13,606	21,943
Current Loans	544,852	601,256
Total Loans	558,458	623,199
Loans 90 Days or More Past Due and Still Accruing	173	0
Real estate – residential | Purchased Loans | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	7,327	12,531
Real estate – residential | Purchased Loans | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	2,093	2,407
Real estate – residential | Purchased Loans | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	4,186	7,005
Consumer installment | Loans Excluding Purchased Loan
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	3,341	4,246
Current Loans	446,515	451,125
Total Loans	449,856	455,371
Loans 90 Days or More Past Due and Still Accruing	259	414
Consumer installment | Loans Excluding Purchased Loan | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	1,842	2,344
Consumer installment | Loans Excluding Purchased Loan | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	972	1,167
Consumer installment | Loans Excluding Purchased Loan | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	527	735
Consumer installment | Purchased Loans
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	722	1,165
Current Loans	23,617	26,023
Total Loans	24,339	27,188
Loans 90 Days or More Past Due and Still Accruing	0	0
Consumer installment | Purchased Loans | Loans 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	420	679
Consumer installment | Purchased Loans | Loans 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	58	237
Consumer installment | Purchased Loans | Loans 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Past Due	$ 244	$ 249