Borrowings - Additional Information (Detail) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Securities sold under agreements to repurchase	$ 28,300,000	$ 28,800,000
Advances from the FHLB	25,000,000	25,000,000
Securities Sold under Agreements to Repurchase
Debt Instrument [Line Items]
Pledged assets separately reported, mortgage-related securities available-for-sale or held-for-investment	22,900,000
Collateralized mortgage obligations, residential \| Securities Sold under Agreements to Repurchase
Debt Instrument [Line Items]
Pledged assets separately reported, mortgage-related securities available-for-sale or held-for-investment	16,000,000
Line of Credit
Debt Instrument [Line Items]
Overnight federal funds borrowed	10,000,000	0
Federal funds available for borrowing	240,000,000
Line of Credit \| Federal Reserve Bank of New York
Debt Instrument [Line Items]
Federal reserve bank, advances, amount of advances by branch	0	0
Federal Home Loan Bank of New York \| Line of Credit
Debt Instrument [Line Items]
Overnight borrowings	$ 775,000,000	$ 700,000,000
Collateralized FHLB Advances \| Weighted Average
Debt Instrument [Line Items]
Federal Home Loan Bank, advances, branch of FHLB Bank, interest rate		0.77%

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Federal Reserve Bank, Advances, Amount Of Advances By Branch

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Pledged Assets Separately Reported, Mortgage-Related Security Available-for-sale or Held-for-investment

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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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