Note 17 - Warrant Liabilities - Fair Value of Warrants (Details) $ in Thousands	Jun. 30, 2020 USD ($) yr	Mar. 31, 2020 USD ($) yr	Dec. 31, 2019 USD ($) yr	Jun. 30, 2019 USD ($) yr	Mar. 31, 2019 USD ($) yr	Dec. 31, 2018 USD ($) yr
Warrant Liabilities (US$’000)	$ 39	$ 61	$ 107	$ 135	$ 956	$ 606
Investor Warrants [Member]
Warrant Liabilities (US$’000)	13	45	71	32	793	503
Placement Agent Warrants [Member]
Warrant Liabilities (US$’000)	$ 26	$ 16	$ 36	$ 103	$ 163	$ 103
Measurement Input, Share Price [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	1	0.95	1.17	1.35	1.95	1.34
Measurement Input, Share Price [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	1	0.95	1.17	1.35	1.95	1.34
Measurement Input, Expected Term [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input | yr	0.05	0.3	0.55	1.05	1.3	1.55
Measurement Input, Expected Term [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input | yr	0.55	0.8	1.05	1.55	1.8	2.05
Measurement Input, Risk Free Interest Rate [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	0.0019	0.001	0.0158	0.0173	0.0227	0.025
Measurement Input, Risk Free Interest Rate [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	0.0018	0.0013	0.0157	0.0173	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	1.43	0.99	0.6	0.9	2.16	1.99
Measurement Input, Price Volatility [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	1.12	0.78	0.8	2.02	1.87	1.76
Measurement Input, Exercise Price [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	1.4927	1.4927	1.4927	6.6	6.6	6.6
Measurement Input, Exercise Price [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	1.4927	1.4927	1.4927	6.6	6.6	6.6
Measurement Input, Quoted Price [Member] | Investor Warrants [Member]
Fair value of the warrants measurement input	0.02	0.07	0.11	50	1,230	780
Measurement Input, Quoted Price [Member] | Placement Agent Warrants [Member]
Fair value of the warrants measurement input	0.2	0.12	0.28	800	1,260	800