Note 10 - Incentive Plans - Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Outstanding (in shares)	387,500	362,640
Outstanding, weighted average exercise price (in dollars per share)	$ 4.57	$ 3.96
Granted (in shares)	94,000	49,000
Granted, weighted average exercise price (in dollars per share)	$ 11.18	$ 8.50
Exercised (in shares)	(19,800)	(13,400)
Exercised, weighted average exercise price (in dollars per share)	$ 3.40	$ 3.43
Cancelled (in shares)	(9,000)	(10,740)
Cancelled (in dollars per share)	$ 4.19	$ 3.42
Outstanding, weighted average remaining contractual term (Year)	6 years 10 months 13 days	7 years 2 months 1 day
Outstanding, aggregate intrinsic value	$ 2,855	$ 1,225
Outstanding (in shares)	452,700	387,500
Outstanding, weighted average exercise price (in dollars per share)	$ 5.97	$ 4.57
Exercisable (in shares)	223,300
Exercisable, weighted average exercise price (in dollars per share)	$ 4.11
Exercisable, weighted average remaining contractual term (Year)	5 years 9 months 3 days
Exercisable, aggregate intrinsic value	$ 1,817