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Share capital (Schedule of Fair Value Weighted-average Assumptions) (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018 USD ($) yr	Sep. 30, 2017 USD ($) yr	Sep. 30, 2018 USD ($) yr	Sep. 30, 2017 USD ($) yr
Disclosure of classes of share capital [abstract]
Expected stock price volatility	[1]		81.00%	59.00%	83.00%
Risk free interest rate			1.30%	1.74%	0.87%
Expected life | yr			3	3	3
Expected forfeiture rate			3.67%	3.36%	4.18%
Expected dividend yield			0.00%	0.00%	0.00%
Share-based payments included in cost of sales
Share-based payments included in general and administrative expenses		334	278	1,711	1,241
Total share-based payments		$ 334	$ 278	$ 1,711	$ 1,241
[1] Expected volatility has been based on historical volatility of the Company's publicly traded shares.

X

- Definition

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

+ References

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The option life of share options granted.

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The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

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The percentage of an expected dividend used to calculate the fair value of share options granted.

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The percentage of an expected forfeiture rate used to calculate the fair value of share options granted.

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Increase (Decrease) Through Share-based Payment Transactions Cost of Sales

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Increase (Decrease) Through Share-based Payment Transactions General and Administrative

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Total share-based payments of stock-options.

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