LOANS AND ALLOWANCE FOR LOAN LOSSES - Loans by Risk Grade (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 14,480,925	$ 12,818,476	$ 8,511,914
1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		587,877
2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		840,372
3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		6,034,399
4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		4,884,542
5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		233,021
6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		86,410
7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		151,845
8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		8
9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		2
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,034,506
2019	138,136
2018	100,900
2017	68,339
2016	28,655
Prior	45,190
Revolving Loans Amortized Cost Basis	211,751
Loans, net of unearned income	1,627,477	802,171	680,720
Commercial, financial and agricultural | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	829,710
2019	2,912
2018	1,055
2017	387
2016	490
Prior	4,961
Revolving Loans Amortized Cost Basis	36,373
Loans, net of unearned income	875,888	22,396
Commercial, financial and agricultural | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,213
2019	1,512
2018	668
2017	996
2016	172
Prior	967
Revolving Loans Amortized Cost Basis	14,317
Loans, net of unearned income	19,845	18,937
Commercial, financial and agricultural | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	109,352
2019	54,266
2018	16,932
2017	17,968
2016	7,027
Prior	3,905
Revolving Loans Amortized Cost Basis	68,806
Loans, net of unearned income	278,256	215,180
Commercial, financial and agricultural | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	86,837
2019	71,645
2018	74,388
2017	37,779
2016	15,359
Prior	23,069
Revolving Loans Amortized Cost Basis	85,366
Loans, net of unearned income	394,443	482,146
Commercial, financial and agricultural | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	4,061
2019	4,269
2018	4,772
2017	7,443
2016	804
Prior	5,842
Revolving Loans Amortized Cost Basis	4,352
Loans, net of unearned income	31,543	33,317
Commercial, financial and agricultural | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	21
2019	72
2018	506
2017	193
2016	3,509
Prior	1,232
Revolving Loans Amortized Cost Basis	632
Loans, net of unearned income	6,165	4,901
Commercial, financial and agricultural | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,312
2019	3,460
2018	2,579
2017	3,573
2016	1,294
Prior	5,214
Revolving Loans Amortized Cost Basis	1,886
Loans, net of unearned income	21,318	25,294
Commercial, financial and agricultural | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	19
Loans, net of unearned income	19	0
Commercial, financial and agricultural | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Consumer installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	142,833
2019	63,892
2018	57,725
2017	17,936
2016	4,808
Prior	11,042
Revolving Loans Amortized Cost Basis	8,759
Loans, net of unearned income	306,995	498,577	482,559
Consumer installment | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	6,782
2019	3,001
2018	1,550
2017	583
2016	95
Prior	1
Revolving Loans Amortized Cost Basis	667
Loans, net of unearned income	12,679	13,184
Consumer installment | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	46
2017	2
2016	0
Prior	63
Revolving Loans Amortized Cost Basis	42
Loans, net of unearned income	153	1,233
Consumer installment | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	15,172
2019	6,960
2018	2,838
2017	887
2016	1,455
Prior	601
Revolving Loans Amortized Cost Basis	4,389
Loans, net of unearned income	32,302	33,314
Consumer installment | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	120,800
2019	53,593
2018	53,182
2017	16,329
2016	3,121
Prior	9,437
Revolving Loans Amortized Cost Basis	3,556
Loans, net of unearned income	260,018	449,224
Consumer installment | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	49
2019	127
2018	28
2017	30
2016	3
Prior	242
Revolving Loans Amortized Cost Basis	8
Loans, net of unearned income	487	208
Consumer installment | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	2
2018	9
2017	0
2016	0
Prior	145
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	156	213
Consumer installment | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	30
2019	209
2018	72
2017	105
2016	134
Prior	553
Revolving Loans Amortized Cost Basis	97
Loans, net of unearned income	1,200	1,191
Consumer installment | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		8
Consumer installment | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		2
Indirect automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	35,595
2018	188,313
2017	188,964
2016	110,066
Prior	57,145
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	580,083	1,061,824	0
Indirect automobile | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	0	0
Indirect automobile | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	81
2017	31
2016	5,356
Prior	3,054
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	8,522	18,354
Indirect automobile | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	35,432
2018	187,656
2017	188,302
2016	103,570
Prior	52,781
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	567,741	1,033,861
Indirect automobile | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	0	4,009
Indirect automobile | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	0	0
Indirect automobile | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	57
2017	70
2016	62
Prior	85
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	274	0
Indirect automobile | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	163
2018	519
2017	561
2016	1,078
Prior	1,225
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	3,546	5,600
Indirect automobile | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Indirect automobile | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	916,353
Loans, net of unearned income	916,353	526,369	360,922
Mortgage warehouse | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	916,353
Loans, net of unearned income	916,353	526,369
Mortgage warehouse | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Mortgage warehouse | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	236,076
2019	13,398
2018	8,944
2017	149,194
2016	141,543
Prior	110,248
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	659,403	564,304	597,945
Municipal | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	91,692
2019	12,685
2018	8,944
2017	143,741
2016	124,929
Prior	97,923
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	479,914	552,062
Municipal | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	73,000
2019	0
2018	0
2017	0
2016	9,410
Prior	0
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	82,410	2,690
Municipal | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	39,990
2019	713
2018	0
2017	5,453
2016	7,204
Prior	5,489
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	58,849	8,925
Municipal | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	31,394
2019	0
2018	0
2017	0
2016	0
Prior	6,836
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	38,230	627
Municipal | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Municipal | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Municipal | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Municipal | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Municipal | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Premium finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	667,425
2019	18,996
2018	515
2017	746
2016	121
Prior	38
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	687,841	654,669	410,381
Premium finance | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Premium finance | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	661,614
2019	18,236
2018	515
2017	746
2016	121
Prior	38
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	681,270	654,069
Premium finance | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Premium finance | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Premium finance | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Premium finance | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Premium finance | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	5,811
2019	760
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	6,571	600
Premium finance | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Premium finance | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Real estate – construction and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	666,893
2019	483,145
2018	226,138
2017	73,061
2016	35,841
Prior	51,658
Revolving Loans Amortized Cost Basis	69,974
Loans, net of unearned income	1,606,710	1,549,062	899,097
Real estate – construction and development | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Real estate – construction and development | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		17,535
Real estate – construction and development | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	59,325
2019	7,035
2018	6,870
2017	8,046
2016	3,415
Prior	6,916
Revolving Loans Amortized Cost Basis	1,293
Loans, net of unearned income	92,900	90,124
Real estate – construction and development | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	605,254
2019	445,496
2018	205,444
2017	50,181
2016	14,672
Prior	26,915
Revolving Loans Amortized Cost Basis	68,574
Loans, net of unearned income	1,416,536	1,377,674
Real estate – construction and development | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,614
2019	26,720
2018	9,612
2017	13,261
2016	17,712
Prior	10,127
Revolving Loans Amortized Cost Basis	107
Loans, net of unearned income	79,153	41,759
Real estate – construction and development | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	685
2019	1,036
2018	3,646
2017	1,302
2016	0
Prior	4,564
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	11,233	17,223
Real estate – construction and development | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	15
2019	2,858
2018	566
2017	271
2016	42
Prior	3,136
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	6,888	4,747
Real estate – construction and development | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Real estate – construction and development | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Real estate – commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,275,475
2019	1,060,392
2018	660,156
2017	655,451
2016	531,935
Prior	1,012,521
Revolving Loans Amortized Cost Basis	104,076
Loans, net of unearned income	5,300,006	4,353,039	3,152,388
Real estate – commercial and farmland | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	161
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	161	208
Real estate – commercial and farmland | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	7,482
2019	540
2018	521
2017	2,131
2016	4,375
Prior	10,663
Revolving Loans Amortized Cost Basis	1,138
Loans, net of unearned income	26,850	35,299
Real estate – commercial and farmland | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	918,939
2019	370,703
2018	143,591
2017	197,942
2016	224,712
Prior	274,665
Revolving Loans Amortized Cost Basis	67,067
Loans, net of unearned income	2,197,619	1,720,039
Real estate – commercial and farmland | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	344,777
2019	584,814
2018	423,241
2017	331,024
2016	242,573
Prior	545,745
Revolving Loans Amortized Cost Basis	34,326
Loans, net of unearned income	2,506,500	2,348,083
Real estate – commercial and farmland | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	4,027
2019	39,216
2018	69,173
2017	80,726
2016	25,561
Prior	94,461
Revolving Loans Amortized Cost Basis	1,274
Loans, net of unearned income	314,438	133,119
Real estate – commercial and farmland | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	10,680
2018	4,895
2017	28,139
2016	7,670
Prior	31,224
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	82,608	53,941
Real estate – commercial and farmland | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	250
2019	54,439
2018	18,574
2017	15,489
2016	27,044
Prior	55,763
Revolving Loans Amortized Cost Basis	271
Loans, net of unearned income	171,830	62,350
Real estate – commercial and farmland | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Real estate – commercial and farmland | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Real estate – residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	786,803
2019	562,538
2018	287,286
2017	206,739
2016	173,832
Prior	522,873
Revolving Loans Amortized Cost Basis	255,986
Loans, net of unearned income	2,796,057	2,808,461	$ 1,927,902
Real estate – residential | 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	19
Revolving Loans Amortized Cost Basis	0
Loans, net of unearned income	19	27
Real estate – residential | 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	37
2019	398
2018	12
2017	121
2016	1,275
Prior	47,286
Revolving Loans Amortized Cost Basis	1,402
Loans, net of unearned income	50,531	92,255
Real estate – residential | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	763,101
2019	529,268
2018	254,632
2017	186,531
2016	154,285
Prior	388,825
Revolving Loans Amortized Cost Basis	203,491
Loans, net of unearned income	2,480,133	2,406,587
Real estate – residential | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	19,296
2019	19,874
2018	15,784
2017	11,607
2016	14,240
Prior	53,869
Revolving Loans Amortized Cost Basis	44,276
Loans, net of unearned income	178,946	222,779
Real estate – residential | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	400
2019	1,768
2018	3,489
2017	3,479
2016	1,151
Prior	12,824
Revolving Loans Amortized Cost Basis	3,618
Loans, net of unearned income	26,729	24,618
Real estate – residential | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	527
2019	1,843
2018	1,030
2017	334
2016	724
Prior	3,391
Revolving Loans Amortized Cost Basis	255
Loans, net of unearned income	8,104	10,132
Real estate – residential | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,442
2019	9,387
2018	12,339
2017	4,667
2016	2,157
Prior	16,659
Revolving Loans Amortized Cost Basis	2,944
Loans, net of unearned income	$ 51,595	52,063
Real estate – residential | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		0
Real estate – residential | 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		$ 0