LOANS HELD FOR INVESTMENT, Age Analysis on Accruing Past-due Loans and Nonaccrual Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	$ 2,993,563	$ 2,748,081
Total Nonaccrual	2,978	5,802
Nonaccrual with no ACL	848
30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	4,855	5,951
90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,805	1,987
Commercial Real Estate [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,046,262	919,358
Total Nonaccrual	0	0
Nonaccrual with no ACL	0
Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	294	342
Commercial Real Estate [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	103	27
Commercial [Member] | Specialized [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	366,405	327,513
Total Nonaccrual	228	38
Nonaccrual with no ACL	0
Commercial [Member] | Specialized [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	129	25
Commercial [Member] | Specialized [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	0	13
Commercial [Member] | General [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	514,567	484,783
Total Nonaccrual	689	3,357
Nonaccrual with no ACL	0
Commercial [Member] | General [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	510	1,451
Commercial [Member] | General [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	375	60
Consumer [Member] | 1-4 Family Residential [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	534,511	460,124
Total Nonaccrual	1,807	1,356
Nonaccrual with no ACL	848
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	1,999	1,389
Consumer [Member] | 1-4 Family Residential [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,033	1,653
Consumer [Member] | Auto Loans [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	316,024	321,476
Total Nonaccrual	0	0
Nonaccrual with no ACL	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	621	707
Consumer [Member] | Auto Loans [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	106	85
Consumer [Member] | Other Consumer [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	77,325	81,308
Total Nonaccrual	32	37
Nonaccrual with no ACL	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	813	1,487
Consumer [Member] | Other Consumer [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	188	149
Construction [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	138,469	153,519
Total Nonaccrual	222	1,014
Nonaccrual with no ACL	0
Construction [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	489	550
Construction [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	$ 0	$ 0