Note 12 - Stockholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Stock-based compensation expense	$ 598	$ 400	$ 1,737	$ 1,698
Cost of Sales [Member]
Stock-based compensation expense	27	14	75	61
Research and Development Expense [Member]
Stock-based compensation expense	0	11	36	64
General and Administrative Expense [Member]
Stock-based compensation expense	$ 571	$ 375	$ 1,626	$ 1,573