Note 8 - Income Taxes (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense (Benefit), Total		$ 0	$ 0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (14,100,000)	11,178,295
Tax Credit Carryforward, Amount		3,175,600
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Subject to Expiration		97,268,927
Operating Loss Carryforwards, Not Subject to Expiration		85,765,810
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Subject to Expiration		184,191,027
Operating Loss Carryforwards, Not Subject to Expiration		$ 778,925