Note 9 - Net Loss Per Share - Schedule of Earnings Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net loss attributable to common shareholders	$ (3,491,071)	$ (3,285,914)	$ (10,344,633)	$ (14,621,750)
Weighted average common shares outstanding used to compute net loss per share, basic and diluted (in shares)	10,162,770	9,130,057	9,496,222	8,283,302
Net loss per share of common stock, basic and diluted: (in dollars per share)	$ (0.34)	$ (0.36)	$ (1.09)	$ (1.77)