Note 13 - Disclosures About Fair Value of Assets and Liabilities - Fair Value Quantitative Information (Details) - Fair Value, Inputs, Level 3 [Member] - Valuation, Market Approach [Member] $ in Thousands	Mar. 31, 2020 USD ($)
Impaired loans (collateral dependent)	$ 2,401
Foreclosed assets held for sale	$ 150
Minimum [Member]
Impaired loans (collateral dependent)	0
Foreclosed assets held for sale	0.35
Maximum [Member]
Impaired loans (collateral dependent)	1
Foreclosed assets held for sale	0.35
Weighted Average [Member]
Impaired loans (collateral dependent)	0.15
Foreclosed assets held for sale	0.35