Note 5 - Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Beginning balance	$ 46	$ 42
Additions based on tax positions related to the current year	8	4
Removal for tax provisions of prior years	0	0
Ending balance	$ 54	$ 46