Note 3 - Shareholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stock-based compensation expense	$ 158	$ 266
Selling and Marketing Expense [Member]
Stock-based compensation expense	20	22
General and Administrative Expense [Member]
Stock-based compensation expense	138	244
Share-Based Payment Arrangement, Option [Member]
Stock-based compensation expense	150	213
Common Stock Award [Member]
Stock-based compensation expense	0	17
Restricted Stock [Member]
Stock-based compensation expense	$ 8	$ 36