Note 13 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Assets Measured on Non-recurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Impaired loans, fair value	$ 2,401	$ 1,483
Foreclosed assets held for sale, fair value	150	233
Fair Value, Inputs, Level 1 [Member]
Impaired loans, fair value
Foreclosed assets held for sale, fair value
Fair Value, Inputs, Level 2 [Member]
Impaired loans, fair value
Foreclosed assets held for sale, fair value
Fair Value, Inputs, Level 3 [Member]
Impaired loans, fair value	2,401	1,483
Foreclosed assets held for sale, fair value	$ 150	$ 233