Note 6 - Accrued Expenses and Other Current Liabilities - Accrued Expenses and Other Current Liabilities (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Compensation	$ 955,494	$ 2,966,139
Deferred revenue	13,601,728	2,298,341
Interest payable		977,724
Lease liability, current portion	427,064	419,709
Research and development vendor costs	231,832	707,685
Professional fees	401,073	288,707
Vacation	340,242	256,402
Other	701,265	722,204
Accrued expenses and other current liabilities	$ 16,658,698	$ 8,636,911