Note 2 - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2024		Sep. 30, 2024		Jun. 30, 2024		Mar. 31, 2024		Dec. 31, 2023		Sep. 30, 2023		Jun. 30, 2023		Mar. 31, 2023		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Numerator for basic and diluted earnings per share - net income	$ 3,051		$ 3,338		$ 2,465		$ 2,594		$ 1,134		$ 2,344		$ 1,887		$ 4,118		$ 11,448	$ 9,483	$ 15,921
Denominator for basic earnings per share - weighted average shares outstanding																	3,672,251	3,610,713	3,564,481
Effect of dilutive securities - employee stock options																	1,446
Denominator for diluted earnings per share - adjusted weighted average shares outstanding																	3,673,697	3,610,713	3,564,481
Earnings per share - basic	$ 0.83	[1]	$ 0.91	[1]	$ 0.67	[1]	$ 0.71	[1]	$ 0.31	[1]	$ 0.65	[1]	$ 0.52	[1]	$ 1.15	[1]	$ 3.12	$ 2.63	$ 4.47
Earnings per share - diluted	$ 0.83	[1]	$ 0.91	[1]	$ 0.67	[1]	$ 0.71	[1]	$ 0.31	[1]	$ 0.65	[1]	$ 0.52	[1]	$ 1.15	[1]	$ 3.12	$ 2.63	$ 4.47

[1] Due to rounding, quarterly earnings per share may not sum to annual earnings per share