Note 8 - Preferred Stock and Common Stock Warrants - Fair Value Assumptions (Details)	Mar. 31, 2023	Dec. 31, 2022
Measurement Input, Share Price [Member]
Warrant measurement input	4.97	4.94
Measurement Input, Exercise Price [Member]
Warrant measurement input	0.01	0.01
Measurement Input, Risk Free Interest Rate [Member]
Warrant measurement input	0.041	0.046
Measurement Input, Price Volatility [Member]
Warrant measurement input	0.483	0.525
Measurement Input, Expected Term [Member]
Warrant measurement input	1.2	1.5