LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans Receivables Related Risk Rating Including Purchased Impaired Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	$ 6,771,490	$ 6,307,060	$ 5,941,098
Construction and Land Development
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	799,938	751,131	765,997
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	888,285	857,805	831,880
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,698,329	1,564,295	1,370,745
Multifamily Real Estate
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	367,257	334,276	337,723
Commercial & Industrial
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	568,602	551,526	469,054
Residential 1-4 Family
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,066,519	1,029,547	992,457
HELOC
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	535,088	526,884	519,196
Consumer and all other
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	573,310	429,525	409,471
Purchased Impaired
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	56,167	59,292	67,170
Purchased Impaired | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	28,689	27,569
Purchased Impaired | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	18,835	21,837
Purchased Impaired | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	7,649	9,256
Purchased Impaired | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	994	630
Purchased Impaired | Construction and Land Development
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	2,694	2,922	5,013
Purchased Impaired | Construction and Land Development | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,121	1,092
Purchased Impaired | Construction and Land Development | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,297	1,432
Purchased Impaired | Construction and Land Development | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	276	398
Purchased Impaired | Construction and Land Development | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	0	0
Purchased Impaired | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	17,906	18,343	20,692
Purchased Impaired | Commercial Real Estate - Owner Occupied | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	5,617	5,520
Purchased Impaired | Commercial Real Estate - Owner Occupied | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	8,337	8,889
Purchased Impaired | Commercial Real Estate - Owner Occupied | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	3,952	3,934
Purchased Impaired | Commercial Real Estate - Owner Occupied | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	0	0
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	16,308	17,303	18,297
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	12,807	10,927
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	2,230	4,638
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,271	1,738
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	0	0
Purchased Impaired | Multifamily Real Estate
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	2,047	2,066	2,092
Purchased Impaired | Multifamily Real Estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	338	343
Purchased Impaired | Multifamily Real Estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,709	1,723
Purchased Impaired | Multifamily Real Estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	0	0
Purchased Impaired | Multifamily Real Estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	0	0
Purchased Impaired | Commercial & Industrial
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	751	1,074	1,354
Purchased Impaired | Commercial & Industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	105	107
Purchased Impaired | Commercial & Industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	368	480
Purchased Impaired | Commercial & Industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	278	487
Purchased Impaired | Commercial & Industrial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	0	0
Purchased Impaired | Residential 1-4 Family
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	15,087	16,200	17,805
Purchased Impaired | Residential 1-4 Family | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	7,735	8,557
Purchased Impaired | Residential 1-4 Family | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	4,624	4,455
Purchased Impaired | Residential 1-4 Family | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,850	2,672
Purchased Impaired | Residential 1-4 Family | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	878	516
Purchased Impaired | HELOC
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	1,156	1,161	1,517
Purchased Impaired | HELOC | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	808	857
Purchased Impaired | HELOC | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	221	183
Purchased Impaired | HELOC | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	11	7
Purchased Impaired | HELOC | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	116	114
Purchased Impaired | Consumer and all other
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	218	223	$ 400
Purchased Impaired | Consumer and all other | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	158	166
Purchased Impaired | Consumer and all other | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	49	37
Purchased Impaired | Consumer and all other | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	11	20
Purchased Impaired | Consumer and all other | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans held for investment, net of deferred fees and costs	$ 0	$ 0