LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Aging of the Loan Portfolio by Segment) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	$ 4,532	$ 3,005
Total Loans	6,898,729	6,307,060	$ 6,148,918
Nonaccrual	20,122	9,973
Current	6,793,302	6,209,924
Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	51,041	59,292	62,346
Current	46,155	55,244
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	24,312	20,245
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,420	4,621
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	54	76
Total Loans	841,738	751,131	776,430
Nonaccrual	5,671	2,037
Current	825,666	744,702
Construction and Land Development | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	3,026	2,922	3,205
Current	2,964	2,838
Construction and Land Development | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7,221	1,162
Construction and Land Development | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	100	232
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	679	35
Total Loans	903,523	857,805	857,142
Nonaccrual	2,205	794
Current	880,575	836,682
Commercial Real Estate - Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	17,668	18,343	19,064
Current	16,562	17,553
Commercial Real Estate - Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,707	1,842
Commercial Real Estate - Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	689	109
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	298	0
Total Loans	1,748,039	1,564,295	1,454,828
Nonaccrual	2,701	0
Current	1,729,184	1,544,623
Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	14,376	17,303	18,141
Current	13,026	16,768
Commercial Real Estate - Non-Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	909	2,369
Commercial Real Estate - Non-Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	571	0
Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	0	0
Total Loans	368,686	334,276	339,313
Nonaccrual	0	0
Current	368,609	332,063
Multifamily Real Estate | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	77	2,066	2,079
Current	77	2,066
Multifamily Real Estate | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	147
Multifamily Real Estate | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	101	9
Total Loans	554,522	551,526	509,857
Nonaccrual	1,252	124
Current	550,731	548,702
Commercial & Industrial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	625	1,074	1,145
Current	625	974
Commercial & Industrial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,558	759
Commercial & Industrial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	255	858
Residential 1-4 Family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	2,360	2,048
Total Loans	1,083,112	1,029,547	999,361
Nonaccrual	6,163	5,279
Current	1,053,440	998,448
Residential 1-4 Family | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	14,077	16,200	16,828
Current	12,003	13,957
Residential 1-4 Family | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,633	7,038
Residential 1-4 Family | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,439	534
Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	143	111
Total Loans	276,572	262,071	255,188
Nonaccrual	174	169
Current	273,547	258,904
Auto | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	0	0	0
Auto | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,415	2,570
Auto | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	293	317
HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	709	635
Total Loans	535,446	526,884	524,097
Nonaccrual	1,791	1,279
Current	529,936	520,833
HELOC | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	982	1,161	1,498
Current	722	865
HELOC | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,400	1,836
HELOC | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	628	1,140
Consumer and all other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	188	91
Total Loans	587,091	429,525	432,702
Nonaccrual	165	291
Current	581,614	424,967
Consumer and all other | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	210	223	$ 386
Current	176	223
Consumer and all other | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,469	2,522
Consumer and all other | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 1,445	$ 1,431