Note 7 - Share-based Compensation - Compensation Cost (Details) - Selling, General and Administrative Expenses [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based compensation	$ 1,197	$ 897	$ 3,450	$ 2,370
Common Stock [Member]
Share-based compensation	100	100	300	300
Employee and Nonemployee Stock Option [Member]
Share-based compensation	112	75	320	188
Restricted Stock Units (RSUs) [Member]
Share-based compensation	$ 985	$ 722	$ 2,830	$ 1,882