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Loans and ACL - Summary of Loan Modifications by Past Due Status (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Sep. 30, 2024
--- | --- | ---
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | $ 9,056 | $ 8,202
Current |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 9,056 | 8,202
30-59 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
60-89 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
90 Days or More Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Secured |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 4,114 | 1,937
Secured | Current |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 4,114 | 1,937
Secured | 30-59 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Secured | 60-89 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Secured | 90 Days or More Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Commercial mortgage owner occupied |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 2,832 | 823
Commercial mortgage owner occupied | Current |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 2,832 | 823
Commercial mortgage owner occupied | 30-59 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Commercial mortgage owner occupied | 60-89 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Commercial mortgage owner occupied | 90 Days or More Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Commercial mortgage multifamily |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 2,917
Commercial mortgage multifamily | Current |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 2,917
Commercial mortgage multifamily | 30-59 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 0
Commercial mortgage multifamily | 60-89 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 0
Commercial mortgage multifamily | 90 Days or More Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 0
Agricultural mortgage |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 1,185 | 1,305
Agricultural mortgage | Current |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 1,185 | 1,305
Agricultural mortgage | 30-59 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Agricultural mortgage | 60-89 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Agricultural mortgage | 90 Days or More Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Agricultural other |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 925 | 1,219
Agricultural other | Current |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 925 | 1,219
Agricultural other | 30-59 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Agricultural other | 60-89 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | 0 | 0
Agricultural other | 90 Days or More Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months | $ 0 | 0
Secured - indirect |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 1
Secured - indirect | Current |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 1
Secured - indirect | 30-59 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 0
Secured - indirect | 60-89 Days Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | 0
Secured - indirect | 90 Days or More Past Due |  |
Financing Receivable, Modified [Line Items] |  |
Financing receivable modified after 12 months |  | $ 0

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