LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Aging of the Loan Portfolio by Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	$ 13,396	$ 8,856
Total Loans	12,610,936	9,716,207
Nonaccrual	28,232	26,953	$ 21,700
Current	12,419,378	9,537,156
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	50,453	41,434
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12,796	11,587
Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	86,681	90,221
Current	70,267	71,213
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	189	180
Total Loans	1,250,924	1,194,821
Nonaccrual	3,703	8,018
Current	1,231,043	1,177,204
Construction and Land Development | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,563	759
Construction and Land Development | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	482	6
Construction and Land Development | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	10,944	8,654
Current	10,465	7,122
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	1,062	3,193
Total Loans	2,041,243	1,337,345
Nonaccrual	6,003	3,636
Current	2,001,074	1,294,975
Commercial Real Estate - Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,482	8,755
Commercial Real Estate - Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,184	1,142
Commercial Real Estate - Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	27,438	25,644
Current	20,074	20,705
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	1,451	0
Total Loans	3,286,098	2,467,410
Nonaccrual	381	1,789
Current	3,269,244	2,447,907
Commercial Real Estate - Non-Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	457	338
Commercial Real Estate - Non-Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	41
Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	14,565	17,335
Current	12,730	15,464
Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	474	0
Total Loans	633,743	548,231
Nonaccrual	0	0
Current	632,952	547,997
Multifamily Real Estate | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	223	0
Multifamily Real Estate | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	146
Multifamily Real Estate | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	94	88
Current	94	88
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	449	132
Total Loans	2,114,033	1,317,135
Nonaccrual	1,735	1,524
Current	2,099,974	1,309,581
Commercial and Industrial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	8,698	3,353
Commercial and Industrial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,598	389
Commercial and Industrial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,579	2,156
Current	590	1,017
Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	674	1,409
Total Loans	724,337	640,419
Nonaccrual	4,301	2,481
Current	703,471	614,732
Residential 1-4 Family - Commercial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,479	6,619
Residential 1-4 Family - Commercial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,207	1,577
Residential 1-4 Family - Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	12,205	13,601
Current	9,667	9,276
Residential 1-4 Family - Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	4,515	2,437
Total Loans	890,503	673,909
Nonaccrual	9,292	7,276
Current	842,667	630,132
Residential 1-4 Family - Consumer | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	16,244	12,049
Residential 1-4 Family - Consumer | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,072	5,143
Residential 1-4 Family - Consumer | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	14,713	16,872
Current	12,005	12,491
Residential 1-4 Family - Revolving
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	3,357	440
Total Loans	659,504	613,383
Nonaccrual	2,080	1,518
Current	637,966	600,055
Residential 1-4 Family - Revolving | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,190	4,611
Residential 1-4 Family - Revolving | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,784	1,644
Residential 1-4 Family - Revolving | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	4,127	5,115
Current	3,635	4,365
Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	272	195
Total Loans	350,419	301,943
Nonaccrual	563	576
Current	346,819	297,442
Auto | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,525	3,320
Auto | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	236	403
Auto | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	4	7
Current	4	7
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	953	870
Total Loans	372,853	379,694
Nonaccrual	77	135
Current	367,794	376,057
Consumer | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,128	1,504
Consumer | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,233	1,096
Consumer | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	668	32
Current	659	18
Other Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater Than 90 Days and Still Accruing	0	0
Total Loans	287,279	241,917
Nonaccrual	97	0
Current	286,374	241,074
Other Commercial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	464	126
Other Commercial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Other Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	344	717
Current	$ 344	$ 660