Note 3 - Securities (Details Textual) $ in Thousands	12 Months Ended
Dec. 31, 2024 USD ($) Securities	Dec. 31, 2023 USD ($)
Deferred Tax Asset, Debt Securities, Available-for-Sale, Unrealized Loss	$ 16,506	$ 16,629
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions \| Securities	564
Debt Securities, Available-for-Sale, Unrealized Loss Position	$ 583,947
Debt Securities, Available-for-Sale, Realized Gain (Loss)	0	(3,332)
Debt Securities, Available-for-Sale, Restricted	536,260	534,465
National Bank of Blacksburg [Member] \| Federal Home Loan Bank of Atlanta [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	515,921
Restricted Stock [Member]
Restricted Investments	1,848	1,264
Securities Called [Member]
Debt Securities, Available-for-Sale, Realized Gain (Loss)	$ 0	$ 3,332

Amount of realized gain (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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