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	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Impaired loans (collateral dependent)	$ 2,689	$ 1,483
Foreclosed assets held for sale	$ 471	$ 233
Minimum [Member]
Impaired loans (collateral dependent)	0	0
Foreclosed assets held for sale	0.04	0.30
Maximum [Member]
Impaired loans (collateral dependent)	0.01	1
Foreclosed assets held for sale	0.57	0.30
Weighted Average [Member]
Impaired loans (collateral dependent)	0.19	0.22
Foreclosed assets held for sale	0.24	0.30