Note 2 - Revenue Recognition - Components of Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Trade receivables	$ 4,300	$ 4,605
Unbilled receivables	2,285	3,082
Other short-term receivables	255	152
Allowance for credit losses	(111)	(110)	$ (223)
Total accounts receivable	$ 6,729	$ 7,729