Note 13 - Equity Offerings - Warrant Assumptions (Details)	Jan. 09, 2023	Aug. 03, 2020	May 22, 2020
Measurement Input, Risk Free Interest Rate [Member] \| Series E Warrants [Member]
Warrants assumptions	0.0366
Measurement Input, Risk Free Interest Rate [Member] \| Series F Warrants [Member]
Warrants assumptions	0.038
Measurement Input, Risk Free Interest Rate [Member] \| Series G Warrants [Member]
Warrants assumptions	0.034
Measurement Input, Risk Free Interest Rate [Member] \| Existing Warrants [Member]
Warrants assumptions		0.0406	0.0406
Measurement Input, Risk Free Interest Rate [Member] \| Series B Warrants [Member]
Warrants assumptions	0.036
Measurement Input, Risk Free Interest Rate [Member] \| Series C Warrants [Member]
Warrants assumptions	0.0366
Measurement Input, Price Volatility [Member] \| Series E Warrants [Member]
Warrants assumptions	1.2407
Measurement Input, Price Volatility [Member] \| Series F Warrants [Member]
Warrants assumptions	0.80
Measurement Input, Price Volatility [Member] \| Series G Warrants [Member]
Warrants assumptions	0.74
Measurement Input, Price Volatility [Member] \| Existing Warrants [Member]
Warrants assumptions		1.3255	1.3535
Measurement Input, Price Volatility [Member] \| Series B Warrants [Member]
Warrants assumptions	1.1542
Measurement Input, Price Volatility [Member] \| Series C Warrants [Member]
Warrants assumptions	1.2765
Measurement Input, Expected Dividend Rate [Member] \| Series E Warrants [Member]
Warrants assumptions	0
Measurement Input, Expected Dividend Rate [Member] \| Series F Warrants [Member]
Warrants assumptions	0
Measurement Input, Expected Dividend Rate [Member] \| Series G Warrants [Member]
Warrants assumptions	0
Measurement Input, Expected Dividend Rate [Member] \| Existing Warrants [Member]
Warrants assumptions		0	0
Measurement Input, Expected Dividend Rate [Member] \| Series B Warrants [Member]
Warrants assumptions	0
Measurement Input, Expected Dividend Rate [Member] \| Series C Warrants [Member]
Warrants assumptions	0
Measurement Input, Expected Term [Member] \| Series E Warrants [Member]
Warrants assumptions	5
Measurement Input, Expected Term [Member] \| Series F Warrants [Member]
Warrants assumptions	2
Measurement Input, Expected Term [Member] \| Series G Warrants [Member]
Warrants assumptions	6
Measurement Input, Expected Term [Member] \| Existing Warrants [Member]
Warrants assumptions		2.6	2.4
Measurement Input, Expected Term [Member] \| Series B Warrants [Member]
Warrants assumptions	6.5
Measurement Input, Expected Term [Member] \| Series C Warrants [Member]
Warrants assumptions	4.5