Note 10 - Stock-based Compensation - Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Stock based compensation	$ 557	$ 127	$ 942	$ 449
Cost of Sales [Member]
Stock based compensation	11	2	18	6
General and Administrative Expense [Member]
Stock based compensation	303	83	511	240
Selling and Marketing Expense [Member]
Stock based compensation	122	19	214	120
Research and Development Expense [Member]
Stock based compensation	$ 121	$ 23	$ 199	$ 83