Stock Option and bonus plans (Details 1)	12 Months Ended
Mar. 31, 2019 $ / shares shares
Stock Option And Bonus Plans Details 1Abstract
Exercisable, Weighted Average Exercise Price \| $ / shares	$ 1.50
Outstanding, Number	850,000
Outstanding, Weighted Average Remaining Life	3 years 6 months
Exercisable, Number	850,000

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

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration