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Investment in community development loans mortgage backed securities small business loans.

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OCI, Debt Securities, Held-To-Maturity, Transfer from Available-For-Sale, Gain (Loss), before Adjustment, before Tax

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Securities pledged to secure public deposit carrying value.

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Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

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Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Notice period the entity is required to deliver before it can redeem an investment calculated using net asset value per share, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, investments calculated by per unit, per membership interest, other equity or ownership interest and alternative investments.

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The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

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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 after tax of other comprehensive income (loss) attributable to parent entity.

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Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of cash inflow from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as investing activity.

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Securities - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
Securities - Additional Information (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investment Holdings [Line Items]
Debt securities, available-for-sale, transfer to held to maturity, fair value	$ 494,200,000
OCI, debt securities, held-to-maturity, transfer from available-for-sale, gain (loss), before adjustment, before Tax	$ 3,800,000
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		$ 78,025,000	$ 8,133,000	$ (9,149,000)
Proceeds from sales of available for sale securities		0	4,402,000	130,912,000
Gross gains			9,000	1,300,000
Gross losses			0	248,000
Securities, carrying value		1,340,000,000	1,040,000,000.00
Equity securities, at fair value		17,283,000	17,368,000
Proceeds from sales of equity securities		0	0	4,148,000
Loss on equity securities		$ 1,302,000	285,000	552,000
Redemption of funds, notice period		60 days
Unfunded commitments		$ 0
Fair value of securities		9,500,000
Amortization of gain on debt securities reclassified to held to maturity from available for sale
Investment Holdings [Line Items]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		551,000	$ 265,000	$ 0
Community Reinvestment Funds
Investment Holdings [Line Items]
Equity securities, at fair value		7,800,000
Other Financial Institutions
Investment Holdings [Line Items]
Unfunded commitments		$ 0