Note 7 - Income Taxes - Reconciliation of Unrecognized Tax Benefit (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Balance at beginning of year	$ 278,000	$ 295,000
Additions based on tax positions of prior years	9,000
Additions based on tax positions of prior years		(17,000)
Balance at end of year	$ 287,000	$ 278,000