Note 12 - Equity Incentive Plan - Total Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Stock-based compensation expense	$ 4,081	$ 2,797	$ 6,626	$ 5,056
Cost of Sales [Member]
Stock-based compensation expense	227	214	403	343
Research and Development Expense [Member]
Stock-based compensation expense	503	402	870	643
Selling, General and Administrative Expenses [Member]
Stock-based compensation expense	$ 3,351	$ 2,181	$ 5,323	$ 4,070