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Loans (Tier Risk Rating System) - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Nonaccrual [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Interest income on nonaccrual loans | $ 33 | $ 28 | $ 85 | $ 69
Minimum [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Repayment period of loan with a reasonable reduction of principal balance |  |  | 2 years |

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