Note 9 - Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Net income to common stockholders	$ 1,710,651	$ 306,893
Weighted average number of common shares outstanding - basic (in shares)	4,509,198	4,486,788
Basic net income per share (in dollars per share)	$ 0.38	$ 0.07
Weighted average number of common shares outstanding - diluted (in shares)	4,563,621	4,497,599
Net income per share - diluted (in dollars per share)	$ 0.37	$ 0.07