Note 9 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	34.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ 0
Valuation Allowance Percentage	100.00%		100.00%
Federal Income Tax Expense (Benefit), Continuing Operations, Total	$ 0
Unrecognized Tax Benefits, Ending Balance	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	0	$ 0
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	291,476,788	40,444,754
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	264,379,011	34,529,255
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration	27,097,777	5,915,499
Operating Loss Carryforwards, Valuation Allowance, Total	58,991,353	9,603,237
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	213,762,905	13,114,182
Operating Loss Carryforwards, Valuation Allowance, Total	21,414,302	1,416,758
Foreign Tax Authority [Member]
Operating Loss Carryforwards, Total	773,455	421,782
Operating Loss Carryforwards, Valuation Allowance, Total	$ 236,746	$ 132,722