Note 6 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 226,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 157,000	$ 157,000
Open Tax Year	2013 2014 2015 2016 2017 2018 2019
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	$ 35,300,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	$ 22,500,000