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Loans - Additional Information (Detail) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Residential mortgage loan | $ 2,632,668 | $ 2,536,043
Asset Pledged as Collateral without Right [Member] | HELOC [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Residential mortgage loan | 14,900 | 11,900
Asset Pledged as Collateral without Right [Member] | Commercial Real Estate [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Residential mortgage loan | 223,000 | 369,500
Asset Pledged as Collateral without Right [Member] | Multi-family Real Estate Loans [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Residential mortgage loan | 33,000 | 47,700
Asset Pledged as Collateral without Right [Member] | Residential Mortgage [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Residential mortgage loan | $ 178,600 | $ 190,100

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