Note 4 - Securities (Details Textual) $ in Thousands	Mar. 31, 2025 USD ($) Securities	Dec. 31, 2024 USD ($)
Debt Securities, Available-for-Sale, Allowance for Credit Losses	$ 0	$ 0
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss	$ 3,289	$ 3,170
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Securities available-for-sale, fair values	Securities available-for-sale, fair values
Deferred Tax Asset, Debt Securities, Available-for-Sale, Unrealized Loss	$ 14,488	$ 16,506
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions \| Securities	545
Debt Securities, Available-for-Sale, Unrealized Loss Position	$ 571,226
Restricted Stock [Member]
Restricted Investments	1,848	$ 1,848
National Bank of Blacksburg [Member] \| Federal Home Loan Bank of Atlanta [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	$ 517,038

Amount, after allowance for credit loss, of accrued interest 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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