Note 2 - Liquidity and Capital Resources (Details Textual) - USD ($)	1 Months Ended		12 Months Ended
	Mar. 25, 2019	Mar. 24, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Income (Loss) Attributable to Parent, Total			$ (11,404,934)	$ (8,122,581)
Net Cash Provided by (Used in) Operating Activities, Total			(8,961,621)	(6,593,950)
Cash and Cash Equivalents, at Carrying Value, Ending Balance			10,380,493	7,217,469
Working Capital			8,600,000
Proceeds from Warrant Exercises				$ 749,233
Subsequent Event [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 19,300,000
Proceeds from Warrant Exercises	$ 11,300,000	$ 11,300,000