Note 11 - Minimum Regulatory Capital Requirement (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
National Bank of Blacksburg [Member]
Banking Regulation, Risk-Weighted Assets, Actual	$ 1,082,158	$ 1,092,101

Amount of risk-weighted assets as defined by regulatory framework.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480696/942-505-50-1

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant