Note 3 - Summary of Significant Accounting Policies - Supplement Information Related to Operating Leases (Details) $ in Thousands	6 Months Ended
Jun. 30, 2019 USD ($)
Operating cash flows used for operating leases (in thousands of U.S. dollars)	$ 93
Right-of-use assets obtained in exchange for new lease liabilities (in thousands of U.S. dollars)	$ 10
Weighted-average remaining lease term (years) (Year)	1 year 259 days
Weighted-average discount rate	6.00%

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
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-Subparagraph (c)
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Weighted average discount rate for operating lease calculated at point in time.

+ References

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Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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-Publisher FASB
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Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

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