Note 5 - Earnings Per Share - Earnings Per Share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income available to common stockholders	$ 400,070	$ 479,582
Basic potential common shares:
Weighted average shares outstanding (in shares)	3,346,185	3,429,002
Weighted average unvested MRP share (in shares)	(3,060)
Weighted average unallocated ESOP shares (in shares)	(157,022)	(175,801)
Basic weighted average shares outstanding (in shares)	3,186,103	3,253,201
Dilutive potential common shares:
Dilutive weighted average shares outstanding (in shares)	3,191,747	3,261,880
Basic earnings per share (in dollars per share)	$ 0.13	$ 0.15
Diluted earnings per share (in dollars per share)	$ 0.13	$ 0.15
MRP Stock Awards [Member]
Dilutive potential common shares:
Weighted average dilutive shares (in shares)	103
Recognition and Retention Plan [Member]
Dilutive potential common shares:
Weighted average dilutive shares (in shares)	5,541	8,679