Note 12 - Stockholders' Equity - Stock-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
Stock-based compensation expense	$ 594	$ 598	$ 1,880	$ 1,737
Cost of Sales [Member]
Stock-based compensation expense	35	27	82	75
Research and Development Expense [Member]
Stock-based compensation expense	8	0	48	36
General and Administrative Expense [Member]
Stock-based compensation expense	$ 551	$ 571	$ 1,750	$ 1,626