Note 10 - Stock-based Compensation Plan - Allocation of Share-based Compensation Expense (Details) - Restricted Stock [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-Based Payment Arrangement, Expense	$ 474	$ 372
Cost of Sales [Member]
Share-Based Payment Arrangement, Expense	19	11
Selling and Marketing Expense [Member]
Share-Based Payment Arrangement, Expense	10	7
Research and Development Expense [Member]
Share-Based Payment Arrangement, Expense	10	19
General and Administrative Expense [Member]
Share-Based Payment Arrangement, Expense	$ 435	$ 335