LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans Receivables Related Risk Rating Excluding Purchased Impaired Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 6,898,729	$ 6,307,060	$ 6,148,918
Construction and Land Development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	841,738	751,131	776,430
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Total Loans	903,523	857,805	857,142
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,748,039	1,564,295	1,454,828
Multifamily Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	368,686	334,276	339,313
Commercial & Industrial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	554,522	551,526	509,857
Residential 1-4 Family
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,083,112	1,029,547	999,361
Auto
Financing Receivable, Recorded Investment [Line Items]
Total Loans	276,572	262,071	255,188
HELOC
Financing Receivable, Recorded Investment [Line Items]
Total Loans	535,446	526,884	524,097
Consumer and all other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	587,091	429,525	$ 432,702
Excluding Purchased Impaired
Financing Receivable, Recorded Investment [Line Items]
Total Loans	6,847,688	6,247,768
Excluding Purchased Impaired | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	6,633,913	6,017,055
Excluding Purchased Impaired | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	175,640	198,078
Excluding Purchased Impaired | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	34,278	28,617
Excluding Purchased Impaired | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,857	4,018
Excluding Purchased Impaired | Construction and Land Development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	838,712	748,209
Excluding Purchased Impaired | Construction and Land Development | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	768,206	667,018
Excluding Purchased Impaired | Construction and Land Development | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	57,190	69,311
Excluding Purchased Impaired | Construction and Land Development | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	13,201	11,857
Excluding Purchased Impaired | Construction and Land Development | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	115	23
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Total Loans	885,855	839,462
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	834,265	801,565
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	47,019	32,364
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,571	5,533
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,733,663	1,546,992
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,702,500	1,505,153
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	23,764	37,631
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,399	4,208
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Multifamily Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	368,609	332,210
Excluding Purchased Impaired | Multifamily Real Estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	361,175	312,711
Excluding Purchased Impaired | Multifamily Real Estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,434	19,499
Excluding Purchased Impaired | Multifamily Real Estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Multifamily Real Estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Commercial & Industrial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	553,897	550,452
Excluding Purchased Impaired | Commercial & Industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	534,594	539,999
Excluding Purchased Impaired | Commercial & Industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	16,400	9,391
Excluding Purchased Impaired | Commercial & Industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,903	1,062
Excluding Purchased Impaired | Commercial & Industrial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Residential 1-4 Family
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,069,035	1,013,347
Excluding Purchased Impaired | Residential 1-4 Family | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,045,736	986,973
Excluding Purchased Impaired | Residential 1-4 Family | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	15,878	18,518
Excluding Purchased Impaired | Residential 1-4 Family | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,480	4,813
Excluding Purchased Impaired | Residential 1-4 Family | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,941	3,043
Excluding Purchased Impaired | Auto
Financing Receivable, Recorded Investment [Line Items]
Total Loans	276,572	262,071
Excluding Purchased Impaired | Auto | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	273,446	258,188
Excluding Purchased Impaired | Auto | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,910	3,648
Excluding Purchased Impaired | Auto | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	143	135
Excluding Purchased Impaired | Auto | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	73	100
Excluding Purchased Impaired | HELOC
Financing Receivable, Recorded Investment [Line Items]
Total Loans	534,464	525,723
Excluding Purchased Impaired | HELOC | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	530,263	519,928
Excluding Purchased Impaired | HELOC | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,427	4,225
Excluding Purchased Impaired | HELOC | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,051	969
Excluding Purchased Impaired | HELOC | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	723	601
Excluding Purchased Impaired | Consumer and all other
Financing Receivable, Recorded Investment [Line Items]
Total Loans	586,881	429,302
Excluding Purchased Impaired | Consumer and all other | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	583,728	425,520
Excluding Purchased Impaired | Consumer and all other | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,618	3,491
Excluding Purchased Impaired | Consumer and all other | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	530	40
Excluding Purchased Impaired | Consumer and all other | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 5	$ 251