Note 4 - Warrants - Assumptions Used (Details)	Mar. 31, 2022	Dec. 31, 2021
Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants, assumptions	0.015	0.001
Minimum [Member] | Measurement Input, Price Volatility [Member]
Warrants, assumptions	0.500	0.718
Minimum [Member] | Measurement Input, Expected Term [Member]
Warrants, assumptions	0.9	0.1
Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants, assumptions	0.024	0.011
Maximum [Member] | Measurement Input, Price Volatility [Member]
Warrants, assumptions	1.122	1.145
Maximum [Member] | Measurement Input, Expected Term [Member]
Warrants, assumptions	3.4	3.6