Note 2 - Basis of Presentation, Principles of Consolidation, Significant Accounting Policies and Liquidity - Schedule of Fair Value Measurements, Recurring and Nonrecurring (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Warrant Liability [Member]
Balance	$ 1,412
Change in fair value - net	(160)
Balance	1,252
Warrant Liability Long Term [Member]
Balance	1,412
Change in fair value - net	(160)
Balance	1,252
Fair Value, Recurring [Member] | Warrant Liability [Member]
Fair value of warrant liability	1,252	$ 1,412
Fair Value, Recurring [Member] | Warrant Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of warrant liability	0	0
Fair Value, Recurring [Member] | Warrant Liability [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of warrant liability	0	0
Fair Value, Recurring [Member] | Warrant Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of warrant liability	$ 1,252	$ 1,412