LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans Stated at Face Amount, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans and Leases Receivable Disclosure [Abstract]
Loans receivable, deferred fees and costs	$ 1,800	$ 3,000
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	6,307,060	5,671,462	$ 5,345,996
Construction and Land Development
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	751,131	749,720	656,380
Commercial Real Estate - Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	857,805	860,086	869,200
Commercial Real Estate - Non-Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	1,564,295	1,270,480	1,183,514
Multifamily Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	334,276	322,528	297,366
Commercial and Industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	551,526	435,365	374,096
Residential 1-4 Family
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	1,029,547	978,469	983,074
Auto
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	262,071	234,061	207,813
HELOC
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	526,884	516,726	523,341
Consumer and all other
Loans and Leases Receivable Disclosure [Line Items]
Loans held for investment, net of deferred fees and costs	$ 429,525	$ 304,027	$ 251,212