Note 11 - Minimum Regulatory Capital Requirement - Minimum Capital Requirements (Details) - National Bank of Blacksburg [Member] $ in Thousands		Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Total capital (to risk weighted assets), actual, amount		$ 198,841	$ 195,782
Total capital (to risk weighted assets), actual, ratio		0.1614	0.1809
Total capital (to risk weighted assets), minimum capital requirement, amount	[1]	$ 129,382	$ 113,627
Total capital (to risk weighted assets), minimum capital requirement, ratio	[1]	0.105	0.105
Total capital (to risk weighted assets), minimum to be well capitalized, amount		$ 123,221	$ 108,216
Total capital (to risk weighted assets), minimum to be well capitalized, ratio		0.10	0.10
Tier 1 capital (to risk weighted assets), actual, amount		$ 188,329	$ 186,429
Tier 1 capital (to risk weighted assets), actual, ratio		0.1528	0.1723
Tier 1 capital (to risk weighted assets), minimum capital requirement, amount	[1]	$ 104,738	$ 91,983
Tier 1 capital (to risk weighted assets), minimum capital requirement, ratio	[1]	0.085	0.085
Tier 1 capital (to risk weighted assets), minimum to be well capitalized, amount		$ 98,577	$ 86,573
Tier 1 capital (to risk weighted assets), minimum to be well capitalized, ratio		0.08	0.08
Common equity tier 1 capital (to risk weighted assets), actual, amount		$ 188,329	$ 186,429
Common equity tier 1 capital (to risk weighted assets), actual, ratio		0.1528	0.1723
Common equity tier 1 capital (to risk weighted assets), minimum capital requirement, amount	[1]	$ 86,254	$ 75,751
Common equity tier 1 capital (to risk weighted assets), minimum capital requirement, ratio	[1]	7.00%	7.00%
Common equity tier 1 capital (to risk weighted assets), minimum to be well capitalized, amount		$ 80,093	$ 70,340
Common equity tier 1 capital (to risk weighted assets), minimum to be well capitalized, ratio		6.50%	6.50%
Tier 1 capital (to average assets), actual, amount		$ 188,329	$ 186,429
Tier 1 capital (to average assets), actual, ratio		0.1025	0.1105
Tier 1 capital (to average assets), minimum capital requirement, amount	[1]	$ 73,493	$ 67,491
Tier 1 capital (to average assets), minimum capital requirement, ratio	[1]	0.04	0.04
Tier 1 capital (to average assets), minimum to be well capitalized, amount		$ 91,866	$ 84,364
Tier 1 capital (to average assets), minimum to be well capitalized, ratio		0.05	0.05

[1] Except with regard to NBB’s Tier 1 capital to average assets ratio, the minimum capital requirement includes the Basel III Capital Rules’ capital conservation buffer (2.50%) which is added to the minimum capital requirements for capital adequacy purposes. NBB’s capital conservation buffer consists of additional CET1 above regulatory minimum requirement. Failure to maintain the prescribed levels would result in limitations on capital distributions and discretionary bonuses to executives.