Note 7 - Income Taxes - Reconciliation of Unrecognized Tax Benefit (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Balance at beginning of year	$ 295,000	$ 275,000
Additions based on tax positions of prior years	(17,000)
Additions based on tax positions of prior years		20,000
Balance at end of year	$ 278,000	$ 295,000