Note 13 - Income Taxes - Unrecognized Tax Benefit Roll Forward (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Balance	$ 450,000	$ 397,000
Additions (deletions) based upon tax positions related to the current year	(227,000)	53,000
Balance	$ 223,000	$ 450,000