LOANS - Loans by Risk Grade (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 9,049,870	$ 8,511,914
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	6,522,448	5,660,457
Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,286,425	2,588,832
1 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	543,786	542,164
1 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	78,248	90,775
2 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	730,621	523,101
2 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	81,069	84,617
3 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,801,373	2,408,128
3 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	787,052	656,289
4 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,225,083	2,047,688
4 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,176,182	1,586,377
5 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	139,936	59,054
5 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	71,293	63,613
6 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	34,414	35,118
6 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	29,661	30,448
7 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	47,232	45,204
7 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	62,920	76,713
8 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
8 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
9 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	3	0
9 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,648,190	1,316,359
Commercial, financial and agricultural | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	252,621	372,686
Commercial, financial and agricultural | 1 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	522,356	530,864
Commercial, financial and agricultural | 1 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	77,725	90,205
Commercial, financial and agricultural | 2 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	642,419	452,250
Commercial, financial and agricultural | 2 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	5,113	2,648
Commercial, financial and agricultural | 3 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	153,181	174,811
Commercial, financial and agricultural | 3 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	18,275	20,489
Commercial, financial and agricultural | 4 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	305,158	137,038
Commercial, financial and agricultural | 4 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	119,108	215,096
Commercial, financial and agricultural | 5 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	18,592	13,714
Commercial, financial and agricultural | 5 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	11,124	14,445
Commercial, financial and agricultural | 6 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	971	5,130
Commercial, financial and agricultural | 6 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	3,974	11,601
Commercial, financial and agricultural | 7 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	5,513	2,552
Commercial, financial and agricultural | 7 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	17,302	18,202
Commercial, financial and agricultural | 8 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Commercial, financial and agricultural | 8 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Commercial, financial and agricultural | 9 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Commercial, financial and agricultural | 9 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – construction and development | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	788,409	671,198
Real estate – construction and development | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	315,141	227,900
Real estate – construction and development | 1 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	40
Real estate – construction and development | 1 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – construction and development | 2 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	18,169	681
Real estate – construction and development | 2 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – construction and development | 3 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	92,379	74,657
Real estate – construction and development | 3 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	21,211	18,022
Real estate – construction and development | 4 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	639,722	582,456
Real estate – construction and development | 4 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	273,958	195,079
Real estate – construction and development | 5 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	33,688	6,264
Real estate – construction and development | 5 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	6,248	2,728
Real estate – construction and development | 6 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,416	4,091
Real estate – construction and development | 6 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	6,309	1,459
Real estate – construction and development | 7 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	3,035	3,009
Real estate – construction and development | 7 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	7,415	10,612
Real estate – construction and development | 8 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – construction and development | 8 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – construction and development | 9 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – construction and development | 9 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,046,347	1,814,529
Real estate – commercial and farmland | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,135,866	1,337,859
Real estate – commercial and farmland | 1 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	9,179	500
Real estate – commercial and farmland | 1 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – commercial and farmland | 2 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	34,661	37,079
Real estate – commercial and farmland | 2 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	9,254	7,407
Real estate – commercial and farmland | 3 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,104,632	888,433
Real estate – commercial and farmland | 3 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	397,977	230,089
Real estate – commercial and farmland | 4 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	766,726	814,068
Real estate – commercial and farmland | 4 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	654,571	1,034,943
Real estate – commercial and farmland | 5 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	80,389	30,364
Real estate – commercial and farmland | 5 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	40,127	29,468
Real estate – commercial and farmland | 6 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	28,510	20,959
Real estate – commercial and farmland | 6 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	12,607	10,063
Real estate – commercial and farmland | 7 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	22,250	23,126
Real estate – commercial and farmland | 7 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	21,330	25,889
Real estate – commercial and farmland | 8 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – commercial and farmland | 8 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – commercial and farmland | 9 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – commercial and farmland | 9 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – residential | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,589,646	1,403,000
Real estate – residential | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	558,458	623,199
Real estate – residential | 1 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	671	16
Real estate – residential | 1 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – residential | 2 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	35,354	33,043
Real estate – residential | 2 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	66,593	74,398
Real estate – residential | 3 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,426,987	1,246,383
Real estate – residential | 3 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	347,811	385,279
Real estate – residential | 4 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	100,068	94,143
Real estate – residential | 4 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	107,495	118,082
Real estate – residential | 5 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	7,218	8,634
Real estate – residential | 5 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	13,760	16,937
Real estate – residential | 6 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	3,456	4,881
Real estate – residential | 6 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	6,644	7,231
Real estate – residential | 7 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	15,892	15,900
Real estate – residential | 7 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	16,155	21,272
Real estate – residential | 8 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – residential | 8 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – residential | 9 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Real estate – residential | 9 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Consumer installment | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	449,856	455,371
Consumer installment | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	24,339	27,188
Consumer installment | 1 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	11,580	10,744
Consumer installment | 1 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	523	570
Consumer installment | 2 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	18	48
Consumer installment | 2 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	109	164
Consumer installment | 3 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	24,194	23,844
Consumer installment | 3 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,778	2,410
Consumer installment | 4 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	413,409	419,983
Consumer installment | 4 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	21,050	23,177
Consumer installment | 5 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	49	78
Consumer installment | 5 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	34	35
Consumer installment | 6 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	61	57
Consumer installment | 6 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	127	94
Consumer installment | 7 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	542	617
Consumer installment | 7 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	718	738
Consumer installment | 8 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Consumer installment | 8 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	0	0
Consumer installment | 9 | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	3	0
Consumer installment | 9 | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 0	$ 0