Note 2 - Liquidity and Capital Resources (Details Textual) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Net Income (Loss) Attributable to Parent, Total	$ (7,039,248)	$ (3,538,069)	$ (3,906,142)	$ (2,947,420)	$ (10,577,317)	$ (6,853,562)
Net Cash Provided by (Used in) Operating Activities, Total					(9,745,061)	(5,459,417)
Cash and Cash Equivalents, at Carrying Value, Ending Balance	142,432,961		$ 7,462,736		142,432,961	$ 7,462,736	$ 39,553,671
Working Capital (Deficit)	$ 144,035				144,035
Proceeds from Issuance or Sale of Equity, Total					$ 112,624,000