Note 8 - Fair Value of Financial Instruments - Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Common stock warrant liability		$ 13,003,075
Fair Value, Inputs, Level 1 [Member]
Common stock warrant liability
Fair Value, Inputs, Level 2 [Member]
Common stock warrant liability
Fair Value, Inputs, Level 3 [Member]
Common stock warrant liability		13,003,075
Money Market Funds [Member]
Money market account	$ 51,792,297	1,789,401
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Money market account	51,792,297	1,789,401
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Money market account
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Money market account