Note 5 - Warrants - Assumptions Used (Details)	Dec. 31, 2021	Dec. 31, 2020
Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants, assumptions	0.001	0.001
Minimum [Member] | Measurement Input, Price Volatility [Member]
Warrants, assumptions	0.718	1.137
Minimum [Member] | Measurement Input, Expected Term [Member]
Warrants, assumptions	0.1	1.1
Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants, assumptions	0.011	0.003
Maximum [Member] | Measurement Input, Price Volatility [Member]
Warrants, assumptions	1.145	1.274
Maximum [Member] | Measurement Input, Expected Term [Member]
Warrants, assumptions	3.6	4.6