Note 1 - Summary of Significant Accounting Policies - Earnings Per Share (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Net income available to common stockholders	$ 1,937,347	$ 1,994,306
Basic potential common shares:
Weighted average shares outstanding (in shares)	3,253,484	3,401,565
Weighted average unvested MRP shares (in shares)	(2,624)
Weighted average unallocated ESOP shares (in shares)	(150,283)	(168,768)
Basic weighted average shares outstanding (in shares)	3,100,577	3,232,797
Dilutive potential common shares:
Dilutive weighted average shares outstanding (in shares)	3,106,112	3,241,121
Basic earnings per share (in dollars per share)	$ 0.62	$ 0.62
Diluted earnings per share (in dollars per share)	$ 0.62	$ 0.62
Management Recognition Plan [Member]
Dilutive potential common shares:
Dilutive weighted average shares outstanding (in shares)	47	12
Recognition and Retention Plan - DO NOT USE[Member]
Dilutive potential common shares:
Dilutive weighted average shares outstanding (in shares)	5,488	8,313