Note 2 - Summary of Significant Accounting Policies - Summary of Stock Compensation Expense by Income Statement Account (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stock compensation expense	$ 872	$ 743	$ 563
Cost of Sales [Member]
Stock compensation expense	63	63	50
General and Administrative Expense [Member]
Stock compensation expense	626	503	380
Selling and Marketing Expense [Member]
Stock compensation expense	113	114	74
Research and Development Expense [Member]
Stock compensation expense	$ 70	$ 63	$ 59