LOANS HELD FOR INVESTMENT, Summary of Internal Classifications of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Loans by Internal Classifications [Abstract]
Loans	$ 2,429,041	$ 2,221,583
Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	2,342,439	2,135,565
Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	1,684	0
Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	84,918	86,018
Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial Real Estate [Member]
Loans by Internal Classifications [Abstract]
Loans	746,775	663,344
Commercial Real Estate [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	684,939	602,250
Commercial Real Estate [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial Real Estate [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	61,836	61,094
Commercial Real Estate [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial [Member] | Specialized [Member]
Loans by Internal Classifications [Abstract]
Loans	390,394	311,686
Commercial [Member] | Specialized [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	384,220	303,831
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	6,174	7,855
Commercial [Member] | Specialized [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Commercial [Member] | General [Member]
Loans by Internal Classifications [Abstract]
Loans	452,776	518,309
Commercial [Member] | General [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	443,221	510,543
Commercial [Member] | General [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	1,684	0
Commercial [Member] | General [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	7,871	7,766
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	387,167	360,315
Consumer [Member] | 1-4 Family Residential [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	379,706	352,930
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	7,461	7,385
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	239,397	205,840
Consumer [Member] | Auto Loans [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	238,310	204,301
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	1,087	1,539
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	69,079	67,595
Consumer [Member] | Other Consumer [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	68,756	67,216
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	323	379
Consumer [Member] | Other Consumer [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Construction [Member]
Loans by Internal Classifications [Abstract]
Loans	143,453	94,494
Construction [Member] | Pass [Member]
Loans by Internal Classifications [Abstract]
Loans	143,287	94,494
Construction [Member] | Special Mention [Member]
Loans by Internal Classifications [Abstract]
Loans	0	0
Construction [Member] | Substandard [Member]
Loans by Internal Classifications [Abstract]
Loans	166	0
Construction [Member] | Doubtful [Member]
Loans by Internal Classifications [Abstract]
Loans	$ 0	$ 0