Note 11 - Fair Value Accounting (Details Textual)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Derivative Liability, Current	$ 7,486,000	$ 24,128,000
Measurement Input, Risk Free Interest Rate [Member]
Derivative Liability, Measurement Input	0.58
Measurement Input, Price Volatility [Member]
Derivative Liability, Measurement Input	112.9
Measurement Input, Expected Term [Member]
Derivative Liability, Measurement Input	3.25
Measurement Input, Expected Dividend Rate [Member]
Derivative Liability, Measurement Input	4.0
Series D Preferred Stock Instrument [Member]
Derivative Liability, Current	$ 7,486,000	$ 24,128,000
Series D Preferred Stock Instrument [Member] | Measurement Input, Expected Term [Member]
Derivative Liability, Measurement Input	3.25