Note 14 - Warrant Liabilities- Fair Value of Warrants (Details) $ in Thousands	Sep. 30, 2023 USD ($) yr		Jun. 30, 2023 USD ($) yr		Dec. 31, 2022 USD ($) yr		Sep. 30, 2022 USD ($) yr		Jun. 30, 2022 USD ($) yr		Dec. 31, 2021 USD ($) yr
Warrant liabilities as of the closing date	$ 0		$ 13		$ 185		$ 1,280		$ 257		$ 2,039
Investor Warrants Issued in Connection with 2021 Financing [Member]
Warrant liabilities as of the closing date	0		12		86		782		167		964
Investor Warrants Issued in Connection with 2020 Financing [Member]
Warrant liabilities as of the closing date	0		0		76		328		57		795
Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Warrant liabilities as of the closing date	0		1		9		106		22		132
Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Warrant liabilities as of the closing date	$ 0		$ 0		$ 14		$ 64		$ 11		$ 148
Measurement Input, Share Price [Member] | Investor Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.91		1.27		0.46		0.92	[1]	0.34	[1]	1	[1]
Measurement Input, Share Price [Member] | Investor Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0.91		1.27		0.46		0.92	[1]	0.34	[1]	1	[1]
Measurement Input, Share Price [Member] | Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.91		1.27		0.46		0.92	[1]	0.34	[1]	1	[1]
Measurement Input, Share Price [Member] | Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0.91		1.27		0.46		0.92	[1]	0.34	[1]	1	[1]
Measurement Input, Expected Term [Member] | Investor Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants | yr	0.88		1.13		1.63		1.88		2.13		2.63
Measurement Input, Expected Term [Member] | Investor Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants | yr	0.2		0.45		0.95		1.2		1.45		1.95
Measurement Input, Expected Term [Member] | Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants | yr	0.88		1.13		1.63		1.88		2.13		2.63
Measurement Input, Expected Term [Member] | Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants | yr	0.2		0.45		0.95		1.2		1.45		1.95
Measurement Input, Risk Free Interest Rate [Member] | Investor Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.0549		0.0534		0.04625		0.0416		0.0297		0.0087
Measurement Input, Risk Free Interest Rate [Member] | Investor Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0.0544		0.0546		0.04716		0.039		0.0279		0.0072
Measurement Input, Risk Free Interest Rate [Member] | Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.0549		0.0534		0.04625		0.0416		0.0297		0.0087
Measurement Input, Risk Free Interest Rate [Member] | Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0.0544		0.0546		0.04716		0.039		0.0279		0.0072
Measurement Input, Expected Dividend Rate [Member] | Investor Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0		0		0		0		0		0
Measurement Input, Expected Dividend Rate [Member] | Investor Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0		0		0		0		0		0
Measurement Input, Expected Dividend Rate [Member] | Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0		0		0		0		0		0
Measurement Input, Expected Dividend Rate [Member] | Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0		0		0		0		0		0
Measurement Input, Price Volatility [Member] | Investor Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.89		1.12		0.9974		1.27		1.24		1.15
Measurement Input, Price Volatility [Member] | Investor Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0.65		0.94		1.1561		1.03		1.07		1.28
Measurement Input, Price Volatility [Member] | Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.89		1.12		0.9974		1.27		1.24		1.15
Measurement Input, Price Volatility [Member] | Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0.65		0.94		1.1561		1.03		1.07		1.28
Measurement Input, Exercise Price [Member] | Investor Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	17.95		17.95	[1]	3.59		3.59		3.59		3.59
Measurement Input, Exercise Price [Member] | Investor Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	10.15		10.15	[1]	2.03		2.03		2.03		2.03
Measurement Input, Exercise Price [Member] | Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	22.4375	[1]	22.4375	[1]	4.4875	[1]	4.4875		4.4875		4.4875
Measurement Input, Exercise Price [Member] | Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	10.15	[1]	10.15	[1]	2.03	[1]	2.03		2.03		2.03
Measurement Input, Quoted Price [Member] | Investor Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.0002		0.0232		0.0329		0.297		0.064		0.37
Measurement Input, Quoted Price [Member] | Investor Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0		0		0.0439		0.195		0.033		0.46
Measurement Input, Quoted Price [Member] | Placement Agent Warrants Issued in Connection with 2021 Financing [Member]
Fair value of the warrants	0.0001		0.0157		0.0256		0.287		0.061		0.36
Measurement Input, Quoted Price [Member] | Placement Agent Warrants Issued in Connection with 2020 Financing [Member]
Fair value of the warrants	0		0		0.0456		0.211		0.036		0.49

[1] To reflect the actual inputs used for the determination of fair value of the Warrants, the stock prices and exercise prices presented were not retrospectively restated for effect of the 1-for-5 reverse stock split effective on January 18, 2023, see Note 4(g).