Note 7 - Income Taxes - Change in Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Balance of unrecognized tax benefits	$ 1,075	$ 768
Reductions due to lapse of applicable statute of limitations	(76)	(38)
Reductions due to tax positions of prior years		0
Additions based on tax positions related to the current year	558	345
Balance of unrecognized tax benefits	$ 1,557	$ 1,075