Note 8 - Basic and Diluted Earnings Per Common Share - Reconciliation of Net Income and Number of Shares Used in Computations of Basic and Diluted EPS (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Net income	$ 1,430,000	$ 1,146,000	$ 552,000	$ 503,000	$ 693,000	$ 1,522,000	$ 3,128,000	$ 2,718,000
Basic weighted average common shares outstanding (in shares)	11,781,071			12,615,187			11,974,336	12,834,505
Add: dilutive effect of common stock options (in shares)	0			73,194			0	75,365
Diluted weighted average common shares outstanding (in shares)	11,781,071			12,688,381			11,974,336	12,909,870
Basic earnings per common share (in dollars per share)	$ 0.12			$ 0.04			$ 0.26	$ 0.21
Diluted earnings per common share (in dollars per share)	$ 0.12			$ 0.04			$ 0.26	$ 0.21