Note 5 - Income Taxes (Details Textual) - USD ($) xbrli-pure in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 452,000
Deferred Tax Assets, Valuation Allowance, Total	8,000,000
Operating Loss Carryforwards, Total	34,700,000
Income Taxes Paid, Net, Total	0	$ 0
Deferred Tax Assets, Net of Valuation Allowance, Total	$ 0		$ 247,000
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%	0.00%