Note 7 - Embedded Derivatives Liabilities - Exercise of Warrants (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Proceeds	$ 1,119	$ 16,647
Series K Warrants [Member]
Common Stock Issued (in shares)	200
Proceeds	$ 1
The Series 2020 A Warrants [Member]
Common Stock Issued (in shares)	1,866,558
Proceeds	$ 1,120
The Series 2020 A Warrants and Series K Warrants [Member]
Common Stock Issued (in shares)	1,866,758
Proceeds	$ 1,121