Note 1 - Summary of Significant Accounting Policies - Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2022
Outstanding (in shares)	387,500
Outstanding, weighted average exercise price (in dollars per share)	$ 4.57
Granted (in shares)	87,000
Granted, weighted average exercise price (in dollars per share)	$ 11.10
Exercised (in shares)	(12,000)
Exercised, weighted average exercise price (in dollars per share)	$ 3.41
Cancelled (in shares)	(4,400)
Cancelled, weighted average exercise price (in dollars per share)	$ 3.36
Outstanding (in shares)	458,100
Outstanding, weighted average exercise price (in dollars per share)	$ 5.82
Outstanding, weighted average remaining contractual term (Year)	6 years 11 months 19 days
Outstanding, aggregate intrinsic value	$ 3,326
Exercisable (in shares)	222,700
Exercisable, weighted average exercise price (in dollars per share)	$ 3.93
Exercisable, weighted average remaining contractual term (Year)	6 years 1 month 13 days
Exercisable, aggregate intrinsic value	$ 2,038