Note 13 - Regulatory Capital and Oversight - Capital Amounts and Ratios (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Common equity tier 1 capital, actual amount	$ 85,074
Common equity tier 1 capital, actual percent of asset	0.1322	[1]
Common equity tier 1 capital, amount required to be adequately capitalized	$ 28,967
Common equity tier 1 capital, percent of assets required to be adequately capitalized	0.045	[1]
Common equity tier 1 capital, excess capital amount	$ 56,107
Common equity tier 1 capital, excess capital percent of assets	0.0872	[1]
Common equity tier 1 capital, amount to be well capitalized under prompt corrective action provisions	$ 41,841
Common equity tier 1 capital, percent of assets to be well capitalized under prompt corrective action provisions	0.065	[1]
Tier 1 leverage, actual amount	$ 85,074
Tier 1 leverage, actual percent of asset	0.1097	[1]
Tier 1 leverage, amount required to be adequately capitalized	$ 31,033
Tier 1 leverage, percent of assets required to be adequately capitalized	0.04	[1]
Tier 1 leverage, excess capital amount	$ 54,041
Tier 1 leverage, excess capital percent of assets	0.0697	[1]
Tier 1 leverage, amount to be well capitalized under prompt corrective action provisions	$ 38,791
Tier 1 leverage, percent of assets to be well capitalized under prompt corrective action provisions	0.05	[1]
Tier 1 risk-based capital, actual amount	$ 85,074
Tier 1 risk-based capital, actual percent of asset	0.1322	[1]
Tier 1 risk-based capital, amount required to be adequately capitalized	$ 38,623
Tier 1 risk-based capital, percent of assets required to be adequately capitalized	0.06	[1]
Tier 1 risk-based capital, excess capital amount	$ 46,451
Tier 1 risk-based capital, excess capital percent of assets	0.0722	[1]
Tier 1 risk-based capital, amount to be well capitalized under prompt corrective action provisions	$ 51,497
Tier 1 risk-based capital, percent of assets to be well capitalized under prompt corrective action provisions	0.08	[1]
Total risk-based capital, actual amount	$ 93,132
Total risk-based capital, actual percent of asset	0.1447	[1]
Total risk-based capital, amount required to be adequately capitalized	$ 51,497
Total risk-based capital, percent of assets required to be adequately capitalized	0.08	[1]
Total risk-based capital, excess capital amount	$ 41,635
Total risk-based capital, excess capital percent of assets	0.0647	[1]
Total risk-based capital, amount to be well capitalized under prompt corrective action provisions	$ 64,371
Total risk-based capital, percent of assets to be well capitalized under prompt corrective action provisions	0.1	[1]

[1] Based upon the Bank's adjusted total assets for the purpose of the Tier 1 leverage capital ratio and risk-weighted assets for the purpose of the risk-based capital ratios.