LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans Stated at Face Amount, Net of Deferred Fees and Costs) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	$ 6,554,046	$ 6,307,060	$ 5,780,502
Loans receivable, deferred fees and costs	768	1,800
Construction and Land Development
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	770,287	751,131	776,698
Commercial Real Estate - Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	870,559	857,805	849,202
Commercial Real Estate - Non-Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	1,631,767	1,564,295	1,296,251
Multifamily Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	353,769	334,276	323,270
Commercial & Industrial
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	576,567	551,526	453,208
Residential 1-4 Family
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	1,057,439	1,029,547	978,478
Auto
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	271,466	262,071	241,737
HELOC
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	527,863	526,884	517,122
Consumer and all other
Loans and Leases Receivable Disclosure [Line Items]
Total loans held for investment, net	$ 494,329	$ 429,525	$ 344,536