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Loans and Allowance for Loan Losses - Schedule of Current, Accruing Past Due, and Non-Accrual Loans on an Amortized Cost Basis by Loan Portfolio Class (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	$ 65,057	$ 108,296
Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	52,216	73,623
Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	139	1,111
Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	12,702	33,562
Total commercial and industrial
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	46,409	30,594
Total commercial and industrial | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	45,593	28,984
Total commercial and industrial | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	1,005
Total commercial and industrial | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	816	605
Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	42,378	27,599
Total commercial and industrial | Commercial, financial and agricultural | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	41,562	26,239
Total commercial and industrial | Commercial, financial and agricultural | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	1,005
Total commercial and industrial | Commercial, financial and agricultural | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	816	355
Total commercial and industrial | Owner-occupied
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	4,031	2,995
Total commercial and industrial | Owner-occupied | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	4,031	2,745
Total commercial and industrial | Owner-occupied | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	0
Total commercial and industrial | Owner-occupied | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	250
Total commercial real estate
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	2,333	76,497
Total commercial real estate | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	2,333	44,100
Total commercial real estate | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	0
Total commercial real estate | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	32,397
Total commercial real estate | Investment properties
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	2,333	76,497
Total commercial real estate | Investment properties | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	2,333	44,100
Total commercial real estate | Investment properties | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	0
Total commercial real estate | Investment properties | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	32,397
Total consumer
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	16,315	1,205
Total consumer | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	4,290	539
Total consumer | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	139	106
Total consumer | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	11,886	560
Total consumer | Consumer mortgages
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	13,012	331
Total consumer | Consumer mortgages | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	1,501	0
Total consumer | Consumer mortgages | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	0	0
Total consumer | Consumer mortgages | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	11,511	331
Total consumer | Other consumer loans
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	3,303	874
Total consumer | Other consumer loans | Current
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	2,789	539
Total consumer | Other consumer loans | Accruing 30-89 Days Past Due
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	139	106
Total consumer | Other consumer loans | Non-accrual
Financing Receivable, Modified [Line Items]
Amortized cost basis of loans, aging analysis	$ 375	$ 229

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