Note 3 - Stocked-based Compensation - Stock Option Activity (Details) - $ / shares	9 Months Ended
	Sep. 30, 2022
Options outstanding, options (in shares)	427,580
Options outstanding (in dollars per share)	$ 3.50
Granted to employees and non-employee directors, options (in shares)	19,600
Granted to employees and non-employee directors (in dollars per share)	$ 3.99
Exercised, options (in shares)	(16,665)
Exercised (in dollars per share)	$ 3.64
Canceled/expired/forfeited, options (in shares)	0
Canceled/expired/forfeited (in dollars per share)	$ 3.62
Options outstanding, options (in shares)	430,515
Options outstanding (in dollars per share)	$ 3.52
Options exercisable, options (in shares)	410,915
Options exercisable (in dollars per share)	$ 3.50