Loans and Allowance for Credit Losses on Loans HFI - Schedule of Payment Status Recorded Investment (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	$ 12,824	$ 23,104
Nonaccrual loans	6,044	8,773
30-89 days past due and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	313	32
90 days or more and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	63	0
Loans current on payments and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	6,404	14,299
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	152	7,038
Nonaccrual loans	0	7,038
Commercial and industrial \| 30-89 days past due and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0	0
Commercial and industrial \| 90 days or more and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0	0
Commercial and industrial \| Loans current on payments and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	152	0
Construction
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	4,773	15,908
Nonaccrual loans	3,305	1,713
Construction \| 30-89 days past due and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0	0
Construction \| 90 days or more and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0	0
Construction \| Loans current on payments and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	1,468	14,195
Residential real estate: \| 1-to-4 family mortgage
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	2,970	22
Nonaccrual loans	1,464	22
Residential real estate: \| Residential line of credit
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	29
Nonaccrual loans	0
Residential real estate: \| 30-89 days past due and accruing interest \| 1-to-4 family mortgage
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	313	0
Residential real estate: \| 30-89 days past due and accruing interest \| Residential line of credit
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0
Residential real estate: \| 90 days or more and accruing interest \| 1-to-4 family mortgage
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0	0
Residential real estate: \| 90 days or more and accruing interest \| Residential line of credit
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0
Residential real estate: \| Loans current on payments and accruing interest \| 1-to-4 family mortgage
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	1,193	0
Residential real estate: \| Loans current on payments and accruing interest \| Residential line of credit
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	29
Commercial real estate: \| Owner-occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	244
Nonaccrual loans	244
Commercial real estate: \| Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	4,593
Nonaccrual loans	1,031
Commercial real estate: \| 30-89 days past due and accruing interest \| Owner-occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0
Commercial real estate: \| 30-89 days past due and accruing interest \| Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0
Commercial real estate: \| 90 days or more and accruing interest \| Owner-occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0
Commercial real estate: \| 90 days or more and accruing interest \| Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0
Commercial real estate: \| Loans current on payments and accruing interest \| Owner-occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0
Commercial real estate: \| Loans current on payments and accruing interest \| Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	3,562
Consumer and other
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	63	136
Nonaccrual loans	0	0
Consumer and other \| 30-89 days past due and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	0	32
Consumer and other \| 90 days or more and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	63	0
Consumer and other \| Loans current on payments and accruing interest
Financing Receivable, Past Due [Line Items]
Loans held for investment, modified	$ 0	$ 104

Accumulated amortized cost excluding accrued interest, of financing receivable modified for debtor experiencing financial difficulty.

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