Note 6 - Regulatory Matters - Actual and Required Capital (Details) $ in Thousands	Mar. 31, 2020 USD ($) Rate	Dec. 31, 2019 USD ($) Rate
Total Capital (to Risk-Weighted Assets), Actual Amount	$ 43,855	$ 42,944
Total Capital (to Risk-Weighted Assets), Actual Ratio	0.14	0.1459
Total Capital (to Risk-Weighted Assets), for Capital Adequacy Purposes, Actual Amount	$ 25,046	$ 23,554
Total Capital (to Risk-Weighted Assets), for Capital Adequacy Purposes, Actual Ratio	0.08	0.08
Total Capital (to Risk-Weighted Assets), to be Well Capitalized, Actual Amount	$ 31,325	$ 29,443
Total Capital (to Risk-Weighted Assets), to be Well Capitalized, Actual Ratio	0.1	0.1
Tier I Capital (to Risk-Weighted Assets), Actual Amount	$ 40,418	$ 39,982
Tier I Capital (to Risk-Weighted Assets), Actual Ratio	0.1291	0.1358
Tier I Capital (to Risk-Weighted Assets), for Capital Adequacy Purposes, Actual Amount	$ 18,785	$ 17,666
Tier I Capital (to Risk-Weighted Assets), for Capital Adequacy Purposes, Actual Ratio	0.06	0.06
Tier I Capital (to Risk-Weighted Assets), to be Well Capitalized, Actual Amount	$ 25,046	$ 23,554
Tier I Capital (to Risk-Weighted Assets), to be Well Capitalized, Actual Ratio	0.08	0.08
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Amount	$ 40,418	$ 39,982
Common Equity Tier 1 Capital (to Risk-Weighted Assets), Actual Ratio	0.1291	0.1358
Common Equity Tier 1 Capital (to Risk-Weighted Assets), for Capital Adequacy Purposes, Actual Amount	$ 14,088	$ 13,249
Common Equity Tier 1 Capital (to Risk-Weighted Assets), for Capital Adequacy Purposes, Actual Ratio (Rate) | Rate	4.50%	4.50%
Common Equity Tier 1 Capital (to Risk-Weighted Assets), to be Well Capitalized, Actual Amount	$ 20,350	$ 19,138
Common Equity Tier 1 Capital (to Risk-Weighted Assets), to be Well Capitalized, Actual Ratio (Rate) | Rate	6.50%	6.50%
Tier I Capital (to Average Assets), Actual Amount	$ 40,418	$ 39,982
Tier I Capital (to Average Assets), Actual Ratio	0.1036	0.103
Tier I Capital (to Average Assets), for Capital Adequacy Purposes, Actual Amount	$ 15,605	$ 15,529
Tier I Capital (to Average Assets), for Capital Adequacy Purposes, Actual Ratio	0.04	0.04
Tier I Capital (to Average Assets), to be Well Capitalized, Actual Amount	$ 19,507	$ 19,411
Tier I Capital (to Average Assets), to be Well Capitalized, Actual Ratio	0.05	0.05