Accrued interest income receivable on investment.

No definition available.

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- Definition

Accrued interest receivable write offs.

+ References

No definition available.

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- Definition

Debt securities available for sale and held to maturity unrealized loss position number of positions.

+ References

No definition available.

+ Details

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- Definition

Investment securities on nonaccrual status.

+ References

No definition available.

+ Details

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

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- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

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- Definition

Amount of securities, mortgage loans, or other financial instruments pledged as collateral for deposits.

+ References

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- Definition

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.

+ References

No definition available.

+ Details

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Investment Securities - Additional Information (Detail)	9 Months Ended	12 Months Ended
Investment Securities - Additional Information (Detail)	Sep. 30, 2025 USD ($) Securities	Dec. 31, 2024 USD ($)	Sep. 30, 2024 USD ($)
Marketable Securities [Line Items]
Number of securities less than 12 months \| Securities	24
Number of securities more than 12 months \| Securities	151
Unrealized losses securities more than 12 months	$ 8,527,000	$ 11,719,000
Securities pledged as collateral	$ 0	0
Number of investment securities \| Securities	268
Accrued interest receivable related to investments	$ 7,600,000	6,500,000
Investment securities on nonaccrual status	0	0
Write-offs of accrued interest receivable	$ 0	0
Municipal Securities [Member]
Marketable Securities [Line Items]
Number of securities more than 12 months \| Securities	97
Unrealized losses securities more than 12 months	$ 31,300,000
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 2,500,000
Mortgage-backed securities [Member]
Marketable Securities [Line Items]
Number of securities more than 12 months \| Securities	49
Unrealized losses securities more than 12 months	$ 27,600,000
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	5,200,000
U.S. government agency securities [Member]
Marketable Securities [Line Items]
Unrealized losses securities more than 12 months	783,000	$ 1,077,000
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 0		$ 0
Agency Securities [Member]
Marketable Securities [Line Items]
Number of securities more than 12 months \| Securities	1
Unrealized losses securities more than 12 months	$ 5,600,000
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 783,000
Mortgage-Backed Securities, Issued by Private Enterprises [Member]
Marketable Securities [Line Items]
Number of securities more than 12 months \| Securities	4
Unrealized losses securities more than 12 months	$ 79,000
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 1,000