Note 16 - The Financing and Warrant Liabilities - Warrant Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jul. 02, 2021	[1]	Feb. 18, 2021	Dec. 14, 2020	Dec. 31, 2019
Proceeds allocated to warrant liabilities	$ 2,039	$ 1,505					$ 107
Change in fair value of warrants	(11,329)	(653)
Investor Warrants Issued in Connection with 2021 Financing [Member]
Proceeds allocated to warrant liabilities	964				$ 10,476
Change in fair value of warrants	(9,512)
Investor Warrants Issued in Connection with 2020 Financing [Member]
Proceeds allocated to warrant liabilities	795	1,279				$ 1,746
Change in fair value of warrants	(484)	(467)
Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Proceeds allocated to warrant liabilities	132				$ 1,445
Change in fair value of warrants	(1,313)
Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Proceeds allocated to warrant liabilities	148	224				$ 305
Change in fair value of warrants	(76)	(81)
Investor Warrants Issued in Connection with 2018 Financing [Member]
Proceeds allocated to warrant liabilities							71
Change in fair value of warrants		(71)
Placement Agent Warrants Issued in Connection with 2018 Financing [Member]
Proceeds allocated to warrant liabilities		2	$ 58				$ 36
Change in fair value of warrants	$ 56	$ (34)

[1] The placement agent warrants issued in the 2018 Financing were cashless exercised on July 2, 2021. As a result, the Company issued approximately 0.04 million shares of the Company’s restricted common stock, with a loss of approximately US$0.02million recognized in other income/(loss) account, which represented the difference between the fair value of these warrants on the date of the exercise and the cost of the Company’s restricted common stock issued, based on the close bid price of the Company’s common stock on the same date.