Note 9 - Net Loss Per Share - Schedule of Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net loss attributable to common shareholders	$ (3,906,142)	$ (7,262,529)	$ (6,853,562)	$ (11,335,836)
Weighted average common shares outstanding used to compute net loss per share, basic and diluted (in shares)	9,187,588	9,126,153	9,159,286	7,852,907
Net loss per share of common stock, basic and diluted: (in dollars per share)	$ (0.43)	$ (0.80)	$ (0.75)	$ (1.44)