LOANS HELD FOR INVESTMENT, Age Analysis on Accruing Past-due Loans and Nonaccrual Loans (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($) Point	Dec. 31, 2019 USD ($)
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	$ 13,067	$ 4,693
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]
Past Due	$ 6,105	7,179
90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,939	1,352
Commercial Real Estate [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	4,382	162
Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	2,846	37
Commercial Real Estate [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	0	116
Commercial [Member] | Specialized [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	205	1,172
Commercial [Member] | Specialized [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	304	708
Commercial [Member] | Specialized [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	0	0
Commercial [Member] | General [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	7,638	2,254
Commercial [Member] | General [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	406	1,747
Commercial [Member] | General [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	0	0
Consumer [Member] | 1-4 Family Residential [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	789	1,105
Consumer [Member] | 1-4 Family Residential [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,203	1,212
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]
Past Due	1,851	932
Consumer [Member] | Auto Loans [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	0	0
Consumer [Member] | Auto Loans [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	567	1,468
Consumer [Member] | Auto Loans [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	73	183
Consumer [Member] | Other Consumer [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	53	0
Consumer [Member] | Other Consumer [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	779	848
Consumer [Member] | Other Consumer [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	15	121
Construction [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Nonaccrual	0	0
Construction [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	0	1,159
Construction [Member] | 90 Days or More Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	$ 0	$ 0