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Loans and Allowance for Credit Losses - Troubled Debt Restructurings Identified During Period (Detail) $ in Thousands | 12 Months Ended
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Dec. 31, 2024 numberOfLoans | Dec. 31, 2023 numberOfLoans | Dec. 31, 2022 USD ($) Contract
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | 2,000 | 0 | 5
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | $ 693
Financing Receivable, Troubled Debt Restructuring |  |  | 676
Financing Receivable Troubled Debt Restructuring Specific Reserve |  |  | 0
Contractual Payment Modification [Member] |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | 683
Contractual Interest Rate Reduction [Member] |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | 10
Extended Maturity [Member] |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | $ 0
Residential Real Estate [Member] |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Contract |  |  | 5
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | $ 693
Financing Receivable, Troubled Debt Restructuring |  |  | 676
Financing Receivable Troubled Debt Restructuring Specific Reserve |  |  | $ 0
Residential Real Estate [Member] | Senior Lien |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Modifications, Number of Contracts | Contract |  |  | 5
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | $ 693
Financing Receivable, Troubled Debt Restructuring |  |  | 676
Financing Receivable Troubled Debt Restructuring Specific Reserve |  |  | 0
Residential Real Estate [Member] | Contractual Payment Modification [Member] |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | 683
Residential Real Estate [Member] | Contractual Payment Modification [Member] | Senior Lien |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | 683
Residential Real Estate [Member] | Contractual Interest Rate Reduction [Member] |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | 10
Residential Real Estate [Member] | Contractual Interest Rate Reduction [Member] | Senior Lien |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | 10
Residential Real Estate [Member] | Extended Maturity [Member] |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | 0
Residential Real Estate [Member] | Extended Maturity [Member] | Senior Lien |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Financing Receivable, Troubled Debt Restructuring, Premodification |  |  | $ 0

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