Note 3 - Summary of Significant Accounting Policies - Operating Lease Expenses and Supplemental Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Long-term operating lease contracts	$ 14	$ 91
Short-term operating lease contracts	138	226
Total	152	317
Operating cash flows used for operating leases (US$’000)	9	91
Right-of-use assets obtained in exchange for new lease liabilities (US$’000)	$ 47	$ 10
Weighted-average remaining lease term (Year)	2 years 273 days	1 year 76 days
Weighted-average discount rate	6.00%	6.00%