Note 9 - Share Capital (Details Textual) - shares	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	141,246	694,322
Stock Issued During Period, Shares, Restricted Stock Award, Gross	42,477	83,378

Number of share options (or share units) exercised during the current period.

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Period Type:	duration