LOANS HELD FOR INVESTMENT, Summary of Internal Classifications of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Loans by Internal Classifications [Abstract]
Loans	$ 2,288,234	$ 2,143,623
Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	2,196,661	2,095,056
Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	22,313
Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	91,573	26,254
Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial Real Estate [Member]
Loans by Internal Classifications [Abstract]
Loans	655,432	658,195
Commercial Real Estate [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	593,746	632,641
Commercial Real Estate [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	22,313
Commercial Real Estate [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	61,686	3,241
Commercial Real Estate [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial [Member] | Specialized [Member]
Loans by Internal Classifications [Abstract]
Loans	340,458	309,505
Commercial [Member] | Specialized [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	331,377	307,239
Commercial [Member] | Specialized [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial [Member] | Specialized [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	9,081	2,266
Commercial [Member] | Specialized [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial [Member] | General [Member]
Loans by Internal Classifications [Abstract]
Loans	578,181	441,398
Commercial [Member] | General [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	566,802	428,155
Commercial [Member] | General [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial [Member] | General [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	11,379	13,243
Commercial [Member] | General [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Consumer [Member] | 1-4 Family Residential [Member]
Loans by Internal Classifications [Abstract]
Loans	372,114	362,796
Consumer [Member] | 1-4 Family Residential [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	364,413	356,422
Consumer [Member] | 1-4 Family Residential [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Consumer [Member] | 1-4 Family Residential [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	7,701	6,374
Consumer [Member] | 1-4 Family Residential [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Consumer [Member] | Auto Loans [Member]
Loans by Internal Classifications [Abstract]
Loans	193,023	215,209
Consumer [Member] | Auto Loans [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	191,727	214,363
Consumer [Member] | Auto Loans [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Consumer [Member] | Auto Loans [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	1,296	846
Consumer [Member] | Auto Loans [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Consumer [Member] | Other Consumer [Member]
Loans by Internal Classifications [Abstract]
Loans	68,877	74,000
Consumer [Member] | Other Consumer [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	68,447	73,716
Consumer [Member] | Other Consumer [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Consumer [Member] | Other Consumer [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	430	284
Consumer [Member] | Other Consumer [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Construction [Member]
Loans by Internal Classifications [Abstract]
Loans	80,149	82,520
Construction [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	80,149	82,520
Construction [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Construction [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Construction [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	$ 0	$ 0