Note 12 - Embedded Derivatives - Exercise of Warrants (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Common Stock Issued (in shares)		53,678,400
Proceeds	$ 1,121	$ 17,082	$ 0
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	28,042,834
Proceeds	$ 1,100	$ 16,826
Series 2020C Warrants [Member]
Common Stock Issued (in shares)	1,866,558	16,532,232
Proceeds	$ 1,120	$ 165
Series 2020 B Warrants [Member]
Common Stock Issued (in shares)		9,103,334
Proceeds		$ 91
The Series 2020 C Warrants and Series K Warrants [Member]
Common Stock Issued (in shares)	1,866,758
Proceeds	$ 1,121