LOANS AND ALLOWANCE FOR CREDIT LOSSES - Schedule of Loan Held for Investment ("HFI") Portfolio by Loan Segment and Class (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	$ 3,399,214			$ 3,314,301
Allowance for loan losses	(44,038)	$ (43,660)	$ (43,666)	(43,888)	$ (44,892)	$ (51,014)	$ (47,729)
Loans held for investment, net of allowance for loan losses	3,355,176			3,270,413
Single-family residential mortgages
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	1,761,352			1,655,382
Allowance for loan losses	(21,770)	(21,766)	(21,988)	(21,585)	(21,843)	(19,106)	(17,518)
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	1,280,028			1,303,019
Allowance for loan losses	(17,820)	(17,527)	(17,639)	(18,162)	(18,672)	(21,423)	(21,879)
Construction and land development
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	154,620			155,464
Allowance for loan losses	(2,033)	(1,954)	(1,446)	(1,502)	(1,492)	(7,971)	(6,053)
Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	151,796			140,061
Allowance for loan losses	(1,619)	(1,593)	(1,672)	(1,647)	(1,883)	(1,493)	(1,339)
SBA
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	48,525			55,978
Allowance for loan losses	(679)	(689)	(769)	(824)	(799)	(791)	(654)
Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	2,893			4,397
Allowance for loan losses	(117)	$ (131)	$ (152)	(168)	$ (203)	$ (230)	$ (286)
Loans held for investment, net of allowance for loan losses
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans held for investment, excluding allowance for loan losses	3,399,214			3,314,301
Allowance for loan losses	(44,038)			(43,888)
Loans held for investment, net of allowance for loan losses	$ 3,355,176			$ 3,270,413