Amortized over remaining expected life of original swap.

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Fair value of interest rate fair value hedging instruments interest income reclassified from AOCI into expense.

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Payment to counterparty in swap termination fee.

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For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.

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The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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Average fixed interest rate related to the group of interest rate derivatives.

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Fixed interest rate related to the interest rate derivative.

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Nominal or face amount used to calculate payments on the derivative liability.

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Nominal or face amount used to calculate payment on derivative.

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Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of asset hedged in fair value hedging relationship.

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Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk. Excludes cumulative basis adjustment related to foreign exchange risk.

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Amount of unrealized gain (loss) related to the fair value of interest rate derivatives designated as fair value hedging instruments, as offset by the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

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Derivatives and Hedging Activities - Additional Information (Detail) - USD ($)				3 Months Ended	9 Months Ended
	Jun. 06, 2025	Dec. 19, 2024	Nov. 01, 2024	Sep. 30, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 10, 2025	Jun. 23, 2025	Dec. 31, 2024	Jul. 12, 2024	Dec. 31, 2023	Nov. 30, 2023	Jun. 30, 2023
Derivatives Fair Value [Line Items]
Interest rate swaps					$ (8,000)	$ (152,000)
Cash in collateral returned				$ 19,573,000	19,573,000				$ 7,100,000
Designated as Hedging Instrument [Member]
Derivatives Fair Value [Line Items]
Notional amount				0	0					$ 10,000,000
Carrying amount of savings deposit				$ 22,000,000	$ 22,000,000				$ 22,100,000
Cash Flow Hedges on 90-day Advances from FHLB [Member]
Derivatives Fair Value [Line Items]
Average fixed interest rate										4.33%
Fixed annual rate				4.38%	4.38%					5.32%
Fair Value Hedging [Member]
Derivatives Fair Value [Line Items]
Remaining maturity				1 year 2 months 12 days	1 year 2 months 12 days				1 year 5 months 1 day
Average fixed interest rate				3.70%	3.70%				3.99%
Fixed annual rate				4.38%	4.38%				5.19%
Amortized over remaining expected life of original swap			24 months
Loans [Member]
Derivatives Fair Value [Line Items]
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities)				$ 80,000	$ 80,000				$ (43,000)
Carrying amount of savings deposit				50,080,000	50,080,000				24,957,000
Loans [Member] \| Designated as Hedging Instrument [Member]
Derivatives Fair Value [Line Items]
Designated hedged items				25,000,000	25,000,000
Loans [Member] \| Fair Value Hedging [Member] \| Fixed Rate Assets [Member]
Derivatives Fair Value [Line Items]
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities)				80,000	80,000						$ (43,000)
Interest Rate Contract [Member] \| Cash Flow Hedges on 90-day Advances from FHLB [Member] \| Designated as Hedging Instrument [Member]
Derivatives Fair Value [Line Items]
Notional amount				$ 0	$ 0
Interest Rate Contract [Member] \| Fair Value Hedging [Member]
Derivatives Fair Value [Line Items]
Cash in collateral returned	$ 336,000	$ 280,000	$ 1,200,000
Average fixed interest rate				4.38%	4.38%		3.62%	3.78%
Fixed annual rate							4.37%	4.31%
Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Derivatives Fair Value [Line Items]
Notional amount				$ 0	$ 0		$ 25,000,000	$ 25,000,000			$ 10,000,000	$ 25,000,000	$ 25,000,000
Interest Rate Swap Contracts and Customer Loan Swaps [Member]
Derivatives Fair Value [Line Items]
Cash collateral from counterparties				450,000	450,000				$ 781,000
Fixed Interest Rate Swap [Member] \| Designated as Hedging Instrument [Member]
Derivatives Fair Value [Line Items]
Interest rate swaps				4,000,000	(8,000,000)
Interest rate swap interest income reclassified from AOCI into expense				$ 0	$ 0
Fixed Interest Rate Swap [Member] \| Fair Value Hedging [Member]
Derivatives Fair Value [Line Items]
Payment to counterparty in swap termination fee	$ 0	32,000	398,000
Fixed Interest Rate Swap [Member] \| Fair Value Hedging [Member] \| Residential mortgage backed securities [Member]
Derivatives Fair Value [Line Items]
Payment to counterparty in swap termination fee		$ 32,000	$ 398,000