LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Aging of the Loan Portfolio by Segment) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	$ 10,953	$ 8,856
Total Loans	11,952,310	9,716,207
Nonaccrual	24,841	26,953
Current	11,776,128	9,537,156
Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	99,932	90,221
Current	79,829	71,213
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	28,075	41,434
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12,381	11,587
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	1,997	180
Total Loans	1,326,679	1,194,821
Nonaccrual	5,513	8,018
Current	1,305,024	1,177,204
Construction and Land Development | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	12,600	8,654
Current	11,123	7,122
Construction and Land Development | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,019	759
Construction and Land Development | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	526	6
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	2,908	3,193
Total Loans	1,921,464	1,337,345
Nonaccrual	3,307	3,636
Current	1,883,881	1,294,975
Commercial Real Estate - Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	26,836	25,644
Current	21,492	20,705
Commercial Real Estate - Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,052	8,755
Commercial Real Estate - Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	480	1,142
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	0	0
Total Loans	2,970,453	2,467,410
Nonaccrual	1,787	1,789
Current	2,944,927	2,447,907
Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	18,850	17,335
Current	16,931	15,464
Commercial Real Estate - Non-Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	760	338
Commercial Real Estate - Non-Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,129	41
Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	0	0
Total Loans	591,431	548,231
Nonaccrual	0	0
Current	590,745	547,997
Multifamily Real Estate | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	90	88
Current	90	88
Multifamily Real Estate | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	596	0
Multifamily Real Estate | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	146
Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	313	132
Total Loans	1,866,625	1,317,135
Nonaccrual	721	1,524
Current	1,858,429	1,309,581
Commercial & Industrial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	4,159	2,156
Current	2,601	1,017
Commercial & Industrial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,565	3,353
Commercial & Industrial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	438	389
Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	1,490	1,409
Total Loans	815,309	713,750
Nonaccrual	4,244	2,481
Current	790,458	687,957
Residential 1-4 Family - Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	13,693	13,707
Current	9,732	9,312
Residential 1-4 Family - Commercial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,059	6,619
Residential 1-4 Family - Commercial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,365	1,577
Residential 1-4 Family - Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	2,476	2,437
Total Loans	865,502	600,578
Nonaccrual	7,119	7,276
Current	830,642	556,907
Residential 1-4 Family - Mortgage | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	17,180	16,766
Current	12,261	12,455
Residential 1-4 Family - Mortgage | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,889	12,049
Residential 1-4 Family - Mortgage | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,196	5,143
Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	153	195
Total Loans	300,631	301,943
Nonaccrual	523	576
Current	297,499	297,442
Auto | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	7	7
Current	7	7
Auto | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,152	3,320
Auto | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	297	403
HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	518	440
Total Loans	672,087	613,383
Nonaccrual	1,395	1,518
Current	658,263	600,055
HELOC | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	5,138	5,115
Current	4,225	4,365
HELOC | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,020	4,611
HELOC | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,753	1,644
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	1,098	870
Total Loans	397,491	379,694
Nonaccrual	124	135
Current	392,478	376,057
Consumer | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	693	32
Current	681	18
Consumer | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,963	1,504
Consumer | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,135	1,096
Other Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	0	0
Total Loans	224,638	241,917
Nonaccrual	108	0
Current	223,782	241,074
Other Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	686	717
Current	686	660
Other Commercial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	126
Other Commercial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 62	$ 0