LOANS AND ALLOWANCE FOR LOAN LOSSES (PCI Loan Portfolios by Segment and Delinquency Status) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 9,124,900	$ 7,053,016
Total Loans	9,290,259	7,141,552
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,237,696	936,857
Total Loans	1,250,448	948,791
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,256,120	925,910
Total Loans	1,293,791	943,933
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,290,797	1,703,592
Total Loans	2,318,589	1,713,659
Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	541,560	356,999
Total Loans	541,730	357,079
Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,086,945	609,829
Total Loans	1,093,771	612,023
Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	701,618	598,935
Total Loans	723,945	612,395
Residential 1-4 Family - Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	571,018	468,763
Total Loans	607,155	485,690
Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	293,505	278,295
Total Loans	296,706	282,474
HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	613,660	531,180
Total Loans	626,916	537,521
Consumer and all other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	531,981	642,656
Total Loans	537,208	647,987
Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	86,007	35,418
Total Loans	101,524	39,021
Purchased Impaired | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,301	1,644
Purchased Impaired | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	13,216	1,959
Purchased Impaired | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,860	2,773
Total Loans	5,183	2,838
Purchased Impaired | Construction and Land Development | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	269	8
Purchased Impaired | Construction and Land Development | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,054	57
Purchased Impaired | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	22,523	13,931
Total Loans	26,720	14,790
Purchased Impaired | Commercial Real Estate - Owner Occupied | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	171	381
Purchased Impaired | Commercial Real Estate - Owner Occupied | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,026	478
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	22,387	6,189
Total Loans	24,680	6,610
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	37	188
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,256	233
Purchased Impaired | Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	84	80
Total Loans	84	80
Purchased Impaired | Multifamily Real Estate | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Impaired | Multifamily Real Estate | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Impaired | Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,315	408
Total Loans	1,851	408
Purchased Impaired | Commercial & Industrial | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Impaired | Commercial & Industrial | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	536	0
Purchased Impaired | Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	14,890	8,630
Total Loans	17,227	9,414
Purchased Impaired | Residential 1-4 Family - Commercial | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	343	433
Purchased Impaired | Residential 1-4 Family - Commercial | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,994	351
Purchased Impaired | Residential 1-4 Family - Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	14,256	2,764
Total Loans	18,002	3,733
Purchased Impaired | Residential 1-4 Family - Mortgage | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,069	343
Purchased Impaired | Residential 1-4 Family - Mortgage | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,677	626
Purchased Impaired | Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11
Total Loans	11	0
Purchased Impaired | Auto | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0
Purchased Impaired | Auto | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0
Purchased Impaired | HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	5,826	445
Total Loans	6,890	950
Purchased Impaired | HELOC | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	405	291
Purchased Impaired | HELOC | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	659	214
Purchased Impaired | Consumer and all other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	855	198
Total Loans	876	198
Purchased Impaired | Consumer and all other | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7	0
Purchased Impaired | Consumer and all other | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 14	$ 0