Note 13 - Regulatory Matters - Capital Amounts and Ratios (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Total Risk-Based Capital	$ 41,430	$ 29,642
Total Risk-Based Capital (to risk-weighted assets)	26.76%	22.36%
Total Risk-Based Capital for Capital Adequacy	$ 13,352	$ 10,606
Total Risk-Based Capital for Capital Adequacy (to risk-weighted assets)	8.625%	8.00%
Total Risk-Based Capital to be Well Capitalized	$ 15,481	$ 13,258
Total Risk-Based Capital to be Well Capitalized (to risk-weighted assets)	10.00%	10.00%
Tier I Capital	$ 39,489	$ 27,969
Tier I Capital (to risk-weighted assets)	25.51%	21.10%
Tier I Capital for Capital Adequacy	$ 10,256	$ 7,955
Tier I Capital for Capital Adequacy (to risk-weighted assets)	6.625%	6.00%	4.00%
Tier I Capital to be Well Capitalized	$ 12,384	$ 10,606
Tier I Capital to be Well Capitalized (to risk-weighted assets)	8.00%	8.00%
Common Equity Tier I	$ 39,489	$ 27,969
Common Equity Tier I (to risk-weighted assets)	25.51%	21.10%
Common Equity Tier I for Capital Adequacy	$ 7,934	$ 5,966
Common Equity Tier I for Capital Adequacy (to risk-weighted assets)	5.125%	4.50%
Common Equity Tier I to be Well Capitalized	$ 10,062	$ 8,617
Common Equity Tier I to be Well Capitalized (to risk-weighted assets)	6.50%	6.50%
Tier I Leverage	$ 39,489	$ 27,969
Tier I Leverage (to adjusted total assets)	16.84%	13.18%
Tier I Leverage for Capital Adequacy	$ 9,379	$ 8,490
Tier I Leverage for Capital Adequacy (to adjusted total assets)	4.00%	4.00%
Tier I Leverage to be Well Capitalized	$ 11,723	$ 10,612
Tier I Leverage to be Well Capitalized (to adjusted total assets)	5.00%	5.00%