Note 1 - Summary of Significant Accounting Policies - Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2021 shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number, Ending Balance (in shares) | shares		387,500
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 4.57
Granted (in shares) | shares	90,000
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 11.13
Exercised (in shares) | shares	(19,800)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 3.40
Cancelled (in shares) | shares	(8,000)
Cancelled, weighted average exercise price (in dollars per share) | $ / shares	$ 3.38
Outstanding (in shares) | shares	449,700
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 5.93
Outstanding, weighted average remaining contractual term (Year)	7 years 1 month 6 days
Outstanding, aggregate intrinsic value | $	$ 2,137
Exercisable (in shares) | shares	213,500
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 3.95
Exercisable, weighted average remaining contractual term (Year)	5 years 10 months 24 days
Exercisable, aggregate intrinsic value | $	$ 1,407