Note 10 - Share-based Compensation - Allocation of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-Based Payment Arrangement, Expense	$ (202)	$ 872	$ 1,648	$ 2,628
Selling, General and Administrative Expenses [Member]
Share-Based Payment Arrangement, Expense	(149)	700	1,404	2,180
Research and Development Expense [Member]
Share-Based Payment Arrangement, Expense	$ (53)	$ 172	$ 244	$ 448