LOANS AND ALLOWANCE FOR CREDIT LOSSES - Loans by Risk Grade (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	$ 5,989,264	$ 4,810,011
Year two	2,709,114	2,376,092
Year three	1,925,433	1,529,977
Year four	1,037,226	1,360,430
Year five	898,344	1,026,801
Prior	1,925,757	1,810,715
Revolving Loans Amortized Cost Basis	1,389,120	1,566,899
Loans, net of unearned income	15,874,258	14,480,925	$ 12,818,476
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	5,955,415	4,795,918
Year two	2,693,326	2,291,183
Year three	1,886,100	1,485,185
Year four	981,400	1,305,726
Year five	879,708	983,087
Prior	1,838,522	1,687,524
Revolving Loans Amortized Cost Basis	1,379,853	1,560,795
Loans, net of unearned income	15,614,324	14,109,418
6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	7,278	1,233
Year two	615	13,633
Year three	2,535	10,143
Year four	30,976	30,038
Year five	6,068	11,965
Prior	29,469	40,641
Revolving Loans Amortized Cost Basis	2,015	887
Loans, net of unearned income	78,956	108,540
7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	26,571	12,860
Year two	15,173	71,276
Year three	36,798	34,649
Year four	24,850	24,666
Year five	12,568	31,749
Prior	57,766	82,550
Revolving Loans Amortized Cost Basis	7,252	5,198
Loans, net of unearned income	180,978	262,948
8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one		0
Year two		0
Year three		0
Year four		0
Year five		0
Prior		0
Revolving Loans Amortized Cost Basis		19
Loans, net of unearned income		19
Commercial, financial and agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	913,036	1,034,506
Year two	280,305	138,136
Year three	193,301	100,900
Year four	120,512	68,339
Year five	53,671	28,655
Prior	48,227	45,190
Revolving Loans Amortized Cost Basis	266,941	211,751
Loans, net of unearned income	1,875,993	1,627,477	802,171
Commercial, financial and agricultural | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	903,630	1,031,173
Year two	279,037	134,604
Year three	188,810	97,815
Year four	118,613	64,573
Year five	50,737	23,852
Prior	40,376	38,744
Revolving Loans Amortized Cost Basis	262,951	209,214
Loans, net of unearned income	1,844,154	1,599,975
Commercial, financial and agricultural | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	190	21
Year two	0	72
Year three	393	506
Year four	427	193
Year five	368	3,509
Prior	1,832	1,232
Revolving Loans Amortized Cost Basis	1,961	632
Loans, net of unearned income	5,171	6,165
Commercial, financial and agricultural | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	9,216	3,312
Year two	1,268	3,460
Year three	4,098	2,579
Year four	1,472	3,573
Year five	2,566	1,294
Prior	6,019	5,214
Revolving Loans Amortized Cost Basis	2,029	1,886
Loans, net of unearned income	26,668	21,318
Commercial, financial and agricultural | 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one		0
Year two		0
Year three		0
Year four		0
Year five		0
Prior		0
Revolving Loans Amortized Cost Basis		19
Loans, net of unearned income		19
Consumer installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	35,840	142,833
Year two	59,504	63,892
Year three	37,485	57,725
Year four	27,482	17,936
Year five	9,890	4,808
Prior	11,561	11,042
Revolving Loans Amortized Cost Basis	9,536	8,759
Loans, net of unearned income	191,298	306,995	498,577
Consumer installment | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	35,781	142,803
Year two	59,221	63,681
Year three	37,195	57,644
Year four	27,266	17,831
Year five	9,787	4,674
Prior	11,021	10,344
Revolving Loans Amortized Cost Basis	9,437	8,662
Loans, net of unearned income	189,708	305,639
Consumer installment | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	0	0
Year two	0	2
Year three	0	9
Year four	0	0
Year five	0	0
Prior	135	145
Revolving Loans Amortized Cost Basis	5	0
Loans, net of unearned income	140	156
Consumer installment | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	59	30
Year two	283	209
Year three	290	72
Year four	216	105
Year five	103	134
Prior	405	553
Revolving Loans Amortized Cost Basis	94	97
Loans, net of unearned income	1,450	1,200
Indirect automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	0	0
Year two	0	35,595
Year three	20,331	188,313
Year four	102,227	188,964
Year five	90,688	110,066
Prior	52,533	57,145
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	265,779	580,083	1,061,824
Indirect automobile | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	0	0
Year two	0	35,432
Year three	20,276	187,737
Year four	101,969	188,333
Year five	90,294	108,926
Prior	51,468	55,835
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	264,007	576,263
Indirect automobile | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	0	0
Year two	0	0
Year three	0	57
Year four	24	70
Year five	10	62
Prior	19	85
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	53	274
Indirect automobile | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	0	0
Year two	0	163
Year three	55	519
Year four	234	561
Year five	384	1,078
Prior	1,046	1,225
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	1,719	3,546
Mortgage warehouse
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	0
Year two	0
Year three	0
Year four	0
Year five	0
Prior	0
Revolving Loans Amortized Cost Basis	787,837
Loans, net of unearned income	787,837	916,353	526,369
Mortgage warehouse | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	0
Year two	0
Year three	0
Year four	0
Year five	0
Prior	0
Revolving Loans Amortized Cost Basis	787,837
Loans, net of unearned income	787,837
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	44,727	236,076
Year two	219,385	13,398
Year three	14,831	8,944
Year four	5,494	149,194
Year five	109,040	141,543
Prior	179,224	110,248
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	572,701	659,403	564,304
Municipal | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	44,727	236,076
Year two	219,385	13,398
Year three	14,831	8,944
Year four	5,494	149,194
Year five	109,040	141,543
Prior	179,224	110,248
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	572,701	659,403
Premium finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	796,923	667,425
Year two	1,154	18,996
Year three	26	515
Year four	0	746
Year five	302	121
Prior	4	38
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	798,409	687,841	654,669
Premium finance | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	787,884	661,614
Year two	1,059	18,236
Year three	26	515
Year four	0	746
Year five	302	121
Prior	4	38
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	789,275	681,270
Premium finance | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	9,039	5,811
Year two	95	760
Year three	0	0
Year four	0	0
Year five	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	9,134	6,571
Real estate – construction and development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	833,764	666,893
Year two	292,041	483,145
Year three	176,483	226,138
Year four	53,509	73,061
Year five	24,590	35,841
Prior	47,626	51,658
Revolving Loans Amortized Cost Basis	24,326	69,974
Loans, net of unearned income	1,452,339	1,606,710	1,549,062
Real estate – construction and development | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	826,094	666,193
Year two	290,814	479,251
Year three	176,476	221,926
Year four	35,773	71,488
Year five	24,533	35,799
Prior	44,514	43,958
Revolving Loans Amortized Cost Basis	21,267	69,974
Loans, net of unearned income	1,419,471	1,588,589
Real estate – construction and development | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	6,527	685
Year two	549	1,036
Year three	0	3,646
Year four	15,260	1,302
Year five	0	0
Prior	2,101	4,564
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	24,437	11,233
Real estate – construction and development | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	1,143	15
Year two	678	2,858
Year three	7	566
Year four	2,476	271
Year five	57	42
Prior	1,011	3,136
Revolving Loans Amortized Cost Basis	3,059	0
Loans, net of unearned income	8,431	6,888
Real estate – commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	2,191,416	1,275,475
Year two	1,208,260	1,060,392
Year three	1,131,384	660,156
Year four	566,131	655,451
Year five	496,672	531,935
Prior	1,160,655	1,012,521
Revolving Loans Amortized Cost Basis	80,399	104,076
Loans, net of unearned income	6,834,917	5,300,006	4,353,039
Real estate – commercial and farmland | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	2,186,291	1,275,225
Year two	1,205,578	995,273
Year three	1,119,239	636,687
Year four	542,295	611,823
Year five	486,477	497,221
Prior	1,103,675	925,534
Revolving Loans Amortized Cost Basis	80,379	103,805
Loans, net of unearned income	6,723,934	5,045,568
Real estate – commercial and farmland | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	416	0
Year two	0	10,680
Year three	1,036	4,895
Year four	14,760	28,139
Year five	5,334	7,670
Prior	21,665	31,224
Revolving Loans Amortized Cost Basis	0	0
Loans, net of unearned income	43,211	82,608
Real estate – commercial and farmland | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	4,709	250
Year two	2,682	54,439
Year three	11,109	18,574
Year four	9,076	15,489
Year five	4,861	27,044
Prior	35,315	55,763
Revolving Loans Amortized Cost Basis	20	271
Loans, net of unearned income	67,772	171,830
Real estate – residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	1,173,558	786,803
Year two	648,465	562,538
Year three	351,592	287,286
Year four	161,871	206,739
Year five	113,491	173,832
Prior	425,927	522,873
Revolving Loans Amortized Cost Basis	220,081	255,986
Loans, net of unearned income	3,094,985	2,796,057	$ 2,808,461
Real estate – residential | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	1,171,008	782,834
Year two	638,232	551,308
Year three	329,247	273,917
Year four	149,990	201,738
Year five	108,538	170,951
Prior	408,240	502,823
Revolving Loans Amortized Cost Basis	217,982	252,787
Loans, net of unearned income	3,023,237	2,736,358
Real estate – residential | 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	145	527
Year two	66	1,843
Year three	1,106	1,030
Year four	505	334
Year five	356	724
Prior	3,717	3,391
Revolving Loans Amortized Cost Basis	49	255
Loans, net of unearned income	5,944	8,104
Real estate – residential | 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one	2,405	3,442
Year two	10,167	9,387
Year three	21,239	12,339
Year four	11,376	4,667
Year five	4,597	2,157
Prior	13,970	16,659
Revolving Loans Amortized Cost Basis	2,050	2,944
Loans, net of unearned income	$ 65,804	51,595
Mortgage Warehouse, Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one		0
Year two		0
Year three		0
Year four		0
Year five		0
Prior		0
Revolving Loans Amortized Cost Basis		916,353
Loans, net of unearned income		916,353
Mortgage Warehouse, Portfolio Segment | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Year one		0
Year two		0
Year three		0
Year four		0
Year five		0
Prior		0
Revolving Loans Amortized Cost Basis		916,353
Loans, net of unearned income		$ 916,353