LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans Receivables Related Risk Rating Excluding Purchased Impaired Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 12,610,936	$ 9,716,207
Construction and Land Development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,250,924	1,194,821
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,041,243	1,337,345
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,286,098	2,467,410
Multifamily Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	633,743	548,231
Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,114,033	1,317,135
Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	724,337	640,419
Residential 1-4 Family - Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Loans	890,503	673,909
Residential 1-4 Family - Revolving
Financing Receivable, Recorded Investment [Line Items]
Total Loans	659,504	613,383
Auto
Financing Receivable, Recorded Investment [Line Items]
Total Loans	350,419	301,943
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Loans	372,853	379,694
Other Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	287,279	241,917
Excluding Purchased Impaired
Financing Receivable, Recorded Investment [Line Items]
Total Loans	12,524,255	9,625,986
Excluding Purchased Impaired | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	12,142,328	9,344,002
Excluding Purchased Impaired | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	316,317	201,174
Excluding Purchased Impaired | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	65,252	80,810
Excluding Purchased Impaired | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	358	0
Excluding Purchased Impaired | Construction and Land Development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,239,980	1,186,167
Excluding Purchased Impaired | Construction and Land Development | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,197,066	1,130,577
Excluding Purchased Impaired | Construction and Land Development | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	37,182	43,894
Excluding Purchased Impaired | Construction and Land Development | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,732	11,696
Excluding Purchased Impaired | Construction and Land Development | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,013,805	1,311,701
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,916,492	1,231,422
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	87,004	50,939
Excluding Purchased Impaired | Commercial Real Estate - Owner Occupied | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	10,309	29,340
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	3,271,533	2,450,075
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,205,463	2,425,500
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	62,368	17,648
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,608	6,927
Excluding Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	94	0
Excluding Purchased Impaired | Multifamily Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total Loans	633,649	548,143
Excluding Purchased Impaired | Multifamily Real Estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	613,844	537,572
Excluding Purchased Impaired | Multifamily Real Estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	19,396	10,571
Excluding Purchased Impaired | Multifamily Real Estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	409	0
Excluding Purchased Impaired | Multifamily Real Estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,112,454	1,314,979
Excluding Purchased Impaired | Commercial and Industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,043,903	1,273,549
Excluding Purchased Impaired | Commercial and Industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	60,495	34,864
Excluding Purchased Impaired | Commercial and Industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	8,048	6,566
Excluding Purchased Impaired | Commercial and Industrial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	8	0
Excluding Purchased Impaired | Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	712,132	626,818
Excluding Purchased Impaired | Residential 1-4 Family - Commercial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	680,894	606,955
Excluding Purchased Impaired | Residential 1-4 Family - Commercial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	24,864	14,876
Excluding Purchased Impaired | Residential 1-4 Family - Commercial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	6,374	4,987
Excluding Purchased Impaired | Residential 1-4 Family - Commercial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Residential 1-4 Family - Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Loans	875,790	657,037
Excluding Purchased Impaired | Residential 1-4 Family - Consumer | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	841,408	624,346
Excluding Purchased Impaired | Residential 1-4 Family - Consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	13,592	17,065
Excluding Purchased Impaired | Residential 1-4 Family - Consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	20,534	15,626
Excluding Purchased Impaired | Residential 1-4 Family - Consumer | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	256	0
Excluding Purchased Impaired | Residential 1-4 Family - Revolving
Financing Receivable, Recorded Investment [Line Items]
Total Loans	655,377	608,268
Excluding Purchased Impaired | Residential 1-4 Family - Revolving | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	641,069	598,444
Excluding Purchased Impaired | Residential 1-4 Family - Revolving | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	6,373	6,316
Excluding Purchased Impaired | Residential 1-4 Family - Revolving | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,935	3,508
Excluding Purchased Impaired | Residential 1-4 Family - Revolving | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Auto
Financing Receivable, Recorded Investment [Line Items]
Total Loans	350,415	301,936
Excluding Purchased Impaired | Auto | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	345,960	296,907
Excluding Purchased Impaired | Auto | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,630	3,590
Excluding Purchased Impaired | Auto | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,825	1,439
Excluding Purchased Impaired | Auto | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total Loans	372,185	379,662
Excluding Purchased Impaired | Consumer | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	371,315	378,873
Excluding Purchased Impaired | Consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	550	547
Excluding Purchased Impaired | Consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	320	242
Excluding Purchased Impaired | Consumer | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Excluding Purchased Impaired | Other Commercial
Financing Receivable, Recorded Investment [Line Items]
Total Loans	286,935	241,200
Excluding Purchased Impaired | Other Commercial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	284,914	239,857
Excluding Purchased Impaired | Other Commercial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,863	864
Excluding Purchased Impaired | Other Commercial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	158	479
Excluding Purchased Impaired | Other Commercial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 0	$ 0