Note 9 - Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Net income	$ 1,706,000	$ 1,123,000	$ 4,069,000	$ 3,421,000
Weighted average shares outstanding (in shares)	3,195,097	3,145,061	3,181,334	3,127,728
Effect of dilutive restricted stock units (in shares)	0	0	241	167
Weighted average shares outstanding - diluted (in shares)	3,195,097	3,145,061	3,181,575	3,127,895
Earnings per common share - basic (in dollars per share)	$ 0.53	$ 0.36	$ 1.28	$ 1.09
Earnings per common share - diluted (in dollars per share)	$ 0.53	$ 0.36	$ 1.28	$ 1.09
Approximate [Member]
Net income	$ 1,705,529	$ 1,123,127	$ 4,068,715	$ 3,421,623