Note 21 - Earnings Per Share - Calculation of Diluted Weighted-average Shares Outstanding (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Basic:
Net income	$ 1,073,514	$ 360,591
Less: Earnings allocated to participating securities	(24,642)	(543)
Net income allocated to common shareholders	$ 1,048,872	$ 360,048
Weighted-average common shares outstanding including participating securities (in shares)	3,410,670	3,443,695
Less: Average participating securities (in shares)	(70,988)	(4,915)
Less: Average unallocated ESOP Shares (in shares)	(176,102)	(181,887)
Average shares (in shares)	3,163,581	3,256,893
Basic (in dollars per share)	$ 0.33	$ 0.11
Diluted:
Net income allocated to common shareholders	$ 1,048,872	$ 360,048
Average shares (in shares)	3,163,581	3,256,893
Add: Dilutive effects of assumed exercises of stock options (in shares)	8,076	8,269
Weighted average shares and dilutive potential common shares (in shares)	3,171,655	3,265,162
Diluted (in dollars per share)	$ 0.33	$ 0.11