Note 7 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Expense (Benefit), Total	$ 0	$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%
Investor [Member]
Stock Issued During Period, Shares, New Issues	6,459,948
Investor Ownership Percentage of Company	60.20%
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards, Total	$ 147,200,000
Operating Loss Carryforwards, Subject to Expiration	139,700,000
Operating Loss Carryforwards, Not Subject to Expiration	7,500,000
Tax Credit Carryforward, Amount	4,200,000
Operating Loss Carryforwards Value of Limitations on Use	124,800,000
Tax Credit Carryforward Value of Limitations on Use	3,650,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	93,400,000
Tax Credit Carryforward, Amount	300,000
Operating Loss Carryforwards Value of Limitations on Use	73,400,000
Tax Credit Carryforward Value of Limitations on Use	$ 324,000