Note 9 - Stock Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Outstanding, shares (in shares)	555,619	594,310	751,827
Outstanding, weighted average exercise price (in dollars per share)	$ 14.35	$ 14.2	$ 13.57
Outstanding, weighted average remaining contractual term (Year)	3 years 2 months 1 day	3 years 4 months 28 days	4 years 3 months 29 days	4 years 9 months 25 days
Outstanding, aggregate instrinsic value	$ 473	$ 1,708	$ 4,158	$ 3,945
Options exercisable, shares (in shares)	425,400	409,119	352,310	433,827
Options exercisable, weighted average exercise price (in dollars per share)	$ 13.92	$ 13.76	$ 13.7	$ 13.31
Options exercisable, weighted average remaining contractual term (Year)	2 years 29 days	2 years 7 months 2 days	3 years 9 months 10 days	4 years 5 months 12 days
Options exercisable, aggregate instrinsic value	$ 454	$ 1,408	$ 2,636	$ 2,392
Granted, shares (in shares)	40,000	35,000	45,000
Granted, weighted average exercise price (in dollars per share)	$ 14.2	$ 18.38	$ 20.44
Granted, aggregate instrinsic value	$ 15	$ 2	$ 39
Exercised, shares (in shares)	(64,219)	(44,690)	(179,517)
Exercised, weighted average exercise price (in dollars per share)	$ 12.75	$ 12.62	$ 12.85
Exercised, aggregate instrinsic value	$ 93	$ 198	$ 1,496
Forfeited, shares (in shares)	(21,000)	(29,001)	(23,000)
Forfeited, weighted average exercise price (in dollars per share)	$ 19.24	$ 18.82	$ 16.5
Forfeited, aggregate instrinsic value	$ 0	$ 1	$ 108
Outstanding, shares (in shares)	510,400	555,619	594,310	751,827
Outstanding, weighted average exercise price (in dollars per share)	$ 14.34	$ 14.35	$ 14.2	$ 13.57