LOANS AND ALLOWANCE FOR LOAN LOSSES (PCI Loan Portfolios by Segment and Delinquency Status) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 7,053,016	$ 6,209,924
Total Loans	7,141,552	6,307,060	$ 5,671,462
Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	35,418	55,244
Total Loans	39,021	59,292	73,737
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	936,857	744,702
Total Loans	948,791	751,131	749,720
Construction and Land Development | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,773	2,838
Total Loans	2,838	2,922	5,986
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	925,910	836,682
Total Loans	943,933	857,805	860,086
Commercial Real Estate - Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	13,931	17,553
Total Loans	14,790	18,343	27,388
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,703,592	1,544,623
Total Loans	1,713,659	1,564,295	1,270,480
Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	6,189	16,768
Total Loans	6,610	17,303	13,519
Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	356,999	332,063
Total Loans	357,079	334,276	322,528
Multifamily Real Estate | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	80	2,066
Total Loans	80	2,066	1,555
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	609,829	548,702
Total Loans	612,023	551,526	435,365
Commercial and Industrial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	408	974
Total Loans	408	1,074	1,813
Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	598,935	535,874
Total Loans	612,395	551,636	517,063
Residential 1-4 Family - Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	8,630	11,165
Total Loans	9,414	12,222	16,119
Residential 1-4 Family - Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	468,763	462,574
Total Loans	485,690	477,911	461,406
Residential 1-4 Family - Mortgage | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,764	2,792
Total Loans	3,733	3,978	5,040
HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	531,180	520,833
Total Loans	537,521	526,884	516,726
HELOC | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	445	865
Total Loans	950	1,161	1,791
Consumer and all other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	642,656	424,967
Total Loans	647,987	429,525	304,027
Consumer and all other | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	198	223
Total Loans	198	223	$ 526
30 To 89 Days Past Due | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,644	2,197
30 To 89 Days Past Due | Construction and Land Development | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	8	0
30 To 89 Days Past Due | Commercial Real Estate - Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	381	271
30 To 89 Days Past Due | Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	188	409
30 To 89 Days Past Due | Multifamily Real Estate | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
30 To 89 Days Past Due | Commercial and Industrial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	44
30 To 89 Days Past Due | Residential 1-4 Family - Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	433	964
30 To 89 Days Past Due | Residential 1-4 Family - Mortgage | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	343	334
30 To 89 Days Past Due | HELOC | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	291	175
30 To 89 Days Past Due | Consumer and all other | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Greater Than 90 Days and still Accruing | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,959	1,851
Greater Than 90 Days and still Accruing | Construction and Land Development | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	57	84
Greater Than 90 Days and still Accruing | Commercial Real Estate - Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	478	519
Greater Than 90 Days and still Accruing | Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	233	126
Greater Than 90 Days and still Accruing | Multifamily Real Estate | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Greater Than 90 Days and still Accruing | Commercial and Industrial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	56
Greater Than 90 Days and still Accruing | Residential 1-4 Family - Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	351	93
Greater Than 90 Days and still Accruing | Residential 1-4 Family - Mortgage | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	626	852
Greater Than 90 Days and still Accruing | HELOC | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	214	121
Greater Than 90 Days and still Accruing | Consumer and all other | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 0	$ 0