Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Number of Days Past Due (Day)		30 days
Number of Days of Delinquent Loans Nonaccrual of Interest (Year)	90 years
Minimum Number of Days Consumer Loans are Past Due for Losses to be Charged Off (Day)	120 days
Maximum Number of Days Consumer Loans are Past Due for Losses to be Charged Off (Day)	180 days
Number of Days Loans Secured by Residential Or Commercial Real Estate Are Past Due for Losses to Be Carged Off (Day)	180 days
Period of Time Between Issuance of Loan Commitment and Closing and Sale of Loans Lower Range (Day)	30 days
Period of Time Between Issuance of Loan Commitments and Closing and Sale of Loans Upper Range (Day)	60 days
Goodwill, Impairment Loss	$ 0	$ 0
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	0	0
Advertising Expense	$ 112	$ 99
Number of Loan Modifications for COVID-19 Related Accommodations	0
National Bank of Blacksburg [Member]
Noncontrolling Interest, Ownership Percentage by Parent	100.00%
Building [Member]
Property, Plant and Equipment, Useful Life (Year)	40 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	10 years
Computer Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years