Note 15 - Fair Values of Financial Instruments - Schedule of Quantitative Information About Level 3 Fair Value Measurements (Details)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Other real estate owned		$ 0
Fair Value, Measurements, Nonrecurring [Member]
Other real estate owned	$ 160,000	$ 0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Other real estate owned	$ 160,000
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Measurement Input, Comparability Adjustment [Member] | Weighted Average [Member]
Other real estate owned, measurement input	0.1