Note 17 - Warrant Liabilities - Fair Value of Warrants (Details) $ in Thousands	Mar. 31, 2020 USD ($) yr		Dec. 31, 2019 USD ($) yr		Mar. 31, 2019 USD ($) yr	Dec. 31, 2018 USD ($) yr
Warrant Liabilities (US$’000)	$ 61		$ 107		$ 956	$ 606
Investor Warrants [Member]
Warrant Liabilities (US$’000)	45		71		793	503
Placement Agent Warrants [Member]
Warrant Liabilities (US$’000)	$ 16		$ 36		$ 163	$ 103
Measurement Input, Share Price [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	0.95		1.17		1.95	1.34
Measurement Input, Share Price [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	0.95		1.17		1.95	1.34
Measurement Input, Expected Term [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input | yr	0.3		0.55		1.3	1.55
Measurement Input, Expected Term [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input | yr	0.8		1.05		1.8	2.05
Measurement Input, Risk Free Interest Rate [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	0.001		0.0158		0.0227	0.025
Measurement Input, Risk Free Interest Rate [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	0.0013		0.0157		0.0227	0.025
Measurement Input, Expected Dividend Rate [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input
Measurement Input, Expected Dividend Rate [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input
Measurement Input, Price Volatility [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	0.99		0.6		2.16	1.99
Measurement Input, Price Volatility [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	0.78		0.8		1.87	1.76
Measurement Input, Exercise Price [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	1.4927	[1]	1.4927	[1]	6.6	6.6
Measurement Input, Exercise Price [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	1.4927	[1]	1.4927	[1]	6.6	6.6
Measurement Input, Quoted Price [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	0.07		0.11		1,230	780
Measurement Input, Quoted Price [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	0.12		0.28		1,260	800

[1] On September 25, 2019, as a result of the close on the first half of a private placement with a selected group of investors, the exercise price of the warrants issued in the 2018 Financing that contain the "full ratchet" price protection in the event of subsequent issuances below the applicable exercise price (the "Down round feature") was adjusted to $1.4927.