Note 7 -Share-based Compensation - Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Shares underlying outstanding awards (in shares)	3,180,882	3,209,141
Shares underlying outstanding awards, weighted average exercise price (in dollars per share)	$ 0.38	$ 0.67
Shares underlying outstanding awards, weighted average remaining contractual term (Year)	4 years 10 months 6 days	5 years 3 months 18 days	3 years 7 months 24 days
Granted (in shares)	472,000	82,716
Granted, weighted average exercise price (in dollars per share)	$ 1.30	$ 0.97
Exercised (in shares)	(12,702)	(110,975)
Exercised, weighted average exercise price (in dollars per share)	$ 0.41	$ 0.36
Forfeited (in shares)	(32,862)
Forfeited, weighted average exercise price (in dollars per share)	$ 0.95
Shares underlying outstanding awards (in shares)	3,607,318	3,180,882	3,209,141
Shares underlying outstanding awards, weighted average exercise price (in dollars per share)	$ 0.59	$ 0.38	$ 0.67
Exercisable options (in shares)	2,905,460
Exercisable options, weighted average exercise price (in dollars per share)	$ 0.37
Exercisable options, weighted average remaining contractual term (Year)	4 years 3 months 25 days