Note 12 - Stock Based Compensation - Stock-based Compensation Expense (Details) - USD ($)		3 Months Ended		9 Months Ended
	Jan. 13, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stock compensation expense		$ 751,652	$ 332,063	$ 6,346,281	$ 726,252
Total stock compensation expense		751,652	332,063	6,346,281	726,252
Liability Options [Member]
Stock compensation expense	$ 1,741,919
Total stock compensation expense	1,741,919
General and Administrative Expense [Member]
Stock compensation expense		510,398	259,347	4,136,727	565,771
Total stock compensation expense		510,398	259,347	4,136,727	565,771
General and Administrative Expense [Member] | Liability Options [Member]
Stock compensation expense	1,074,183
Total stock compensation expense	1,074,183
Research and Development Expense [Member]
Stock compensation expense		241,254	72,716	2,209,554	160,481
Total stock compensation expense		$ 241,254	$ 72,716	$ 2,209,554	$ 160,481
Research and Development Expense [Member] | Liability Options [Member]
Stock compensation expense	667,736
Total stock compensation expense	$ 667,736