Note 5 - Debt Securities (Details Textual) $ in Thousands	12 Months Ended
Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Accrued Interest Receivable Debt Securities Available for Sale	$ 3,100	$ 3,000
Debt Securities, Available-for-Sale, Total	502,762	405,201
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Ending Balance	0
Accrued Interest Receivable Debt Securities Held to Maturity	1,100	1,100
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	94,227	96,163
Debt Securities, Held-to-Maturity, Nonaccrual	0	0
Proceeds from Maturities, Prepayments and Calls of Held-to-Maturity Securities	0	0	$ 0
Debt Securities, Held-to-Maturity, 30 Days or More Past Due, Still Accruing	0	0
Asset Pledged as Collateral [Member]
Debt Securities, Available-for-Sale, Total	$ 349,400	$ 238,600
Debt Securities, Available-for-Sale [Member]
State and Political Subdivisions Securities Number of States with Highest Volume	5
US States and Political Subdivisions Debt Securities [Member] \| Securities Issuers Concentration Risk [Member] \| Securities, Total [Member]
Debt Securities, Available-for-Sale, Total	$ 0
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	$ 0
Residential Mortgage-Backed Securities [Member] \| Minimum [Member]
Debt Securities, Available for Sale, Contractual Maturity, Term (Year)	1 year
Debt Securities, Available for Sale, Estimated Average Life (Month)	2 months
Residential Mortgage-Backed Securities [Member] \| Maximum [Member]
Debt Securities, Available for Sale, Contractual Maturity, Term (Year)	49 years
Debt Securities, Available for Sale, Estimated Average Life (Month)	17 years
Debt Securities, Held-to-Maturity [Member]
State and Political Subdivisions Securities Number of States with Highest Volume	5

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Represents accrued interest receivable debt securities held to maturity.

+ References

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The term of contractual maturity on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

No definition available.

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The estimated average life on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amount of investment in debt security measured at amortized cost (held-to-maturity), 30 days or more past due and still accruing.

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Represents state and political subdivisions securities number of states with highest volume.

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Amount 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 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).

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Amount of investment in debt security measured at amortized cost (held-to-maturity) on nonaccrual status.

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Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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The cash inflow associated with the maturity, prepayments and calls (requests for early payments) of debt securities designated as held-to-maturity.

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