Note 10 - Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Basic and diluted earnings per share calculation:
Net income to common stockholders	$ 1,613,005	$ 1,624,453
Weighted average number of common shares outstanding - basic (in shares)	4,553,080	4,522,536
Basic net income per share (in dollars per share)	$ 0.35	$ 0.36
Weighted average number of common shares outstanding - diluted (in shares)	4,619,046	4,583,115
Diluted net income per share (in dollars per share)	$ 0.35	$ 0.35