Note 3 - Summary of Significant Accounting Policies - Summary of Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Warrant liabilities (Note 17)	$ 135	$ 606
Fair Value, Inputs, Level 1 [Member]
Warrant liabilities (Note 17)
Fair Value, Inputs, Level 2 [Member]
Warrant liabilities (Note 17)
Fair Value, Inputs, Level 3 [Member]
Warrant liabilities (Note 17)	$ 135	$ 606