LOANS HELD FOR INVESTMENT, Age Analysis on Accruing Past-due Loans and Nonaccrual Loans (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($) Point	Dec. 31, 2020 USD ($)
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	$ 2,303,462	$ 2,221,583
Nonaccrual	$ 11,144	13,718
Number of points on a grading scale for loans | Point	13
30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	$ 8,625	6,560
90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	1,394	1,246
Commercial Real Estate [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	682,017	663,344
Nonaccrual	2,559	6,311
Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	5,561	914
Commercial Real Estate [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	44	34
Commercial [Member] | Specialized [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	323,576	311,686
Nonaccrual	169	272
Commercial [Member] | Specialized [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	230	241
Commercial [Member] | Specialized [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	0	0
Commercial [Member] | General [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	492,314	518,309
Nonaccrual	6,008	5,489
Commercial [Member] | General [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	1,027	1,891
Commercial [Member] | General [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	93	149
Consumer [Member] | 1-4 Family Residential [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	375,302	360,315
Nonaccrual	2,154	1,595
Consumer [Member] | 1-4 Family Residential [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	590	2,089
Consumer [Member] | 1-4 Family Residential [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	1,156	906
Consumer [Member] | Auto Loans [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	230,570	205,840
Nonaccrual	40	0
Consumer [Member] | Auto Loans [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	325	738
Consumer [Member] | Auto Loans [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	29	38
Consumer [Member] | Other Consumer [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	68,098	67,595
Nonaccrual	48	51
Consumer [Member] | Other Consumer [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	432	481
Consumer [Member] | Other Consumer [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	72	119
Construction [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	131,585	94,494
Nonaccrual	166	0
Construction [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	460	206
Construction [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Loans	$ 0	$ 0