Note 3 - Earnings Per Share - Shares Used in Calculation of Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Weighted-average common shares outstanding (in shares)	9,950,342	9,927,946	9,946,146	9,924,597
Average treasury stock shares (in shares)	(1,879,310)	(1,835,452)	(1,869,706)	(1,818,080)
Weighted-average common shares and common stock equivalents used to calculate basic earnings per share (in shares)	8,071,032	8,092,494	8,076,440	8,106,517
Additional common stock equivalents (stock options and restricted stock) used to calculate diluted earnings per share (in shares)	15,840	8,812	15,840	8,812
Weighted-average common shares and common stock equivalents used to calculate diluted earnings per share (in shares)	8,086,872	8,101,306	8,092,280	8,115,329