Note 5 - Income Taxes (Details Textual) - USD ($) xbrli-pure in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			$ 413,000
Deferred Tax Assets, Valuation Allowance, Total	$ 8,100,000		8,100,000
Operating Loss Carryforwards, Total	35,000,000		35,000,000
Income Taxes Paid, Net, Total	0	$ 0	0	$ 0
Deferred Tax Assets, Net of Valuation Allowance, Total	$ 0		$ 0		$ 247,000
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%		0.00%