The aggregate difference between the fair value at initial recognition and the transaction price for financial instruments that is yet to be recognised in profit or loss. [Refer: Financial instruments, class [member]]

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- Definition

The spot exchange rate at the end of the reporting period. Exchange rate is the ratio of exchange for two currencies. Spot exchange rate is the exchange rate for immediate delivery.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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No definition available.

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The increase (decrease) in the aggregate difference between the fair value at initial recognition and the transaction price of financial instruments yet to be recognised in profit or loss resulting from amounts recognised in profit or loss. [Refer: Aggregate difference between fair value at initial recognition and transaction price yet to be recognised in profit or loss; Financial instruments, class [member]]

+ References

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Aggregate difference between fair value at initial recognition and transaction price recognised in profit or loss.

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Approximate value of currency expected to be settled in fourth quarter.

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Approximate value of currency expected to be settled in fourth quarter, portion held as fund deposit.

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The increase (decrease) in the aggregate difference between the fair value at initial recognition and the transaction price of financial instruments yet to be recognised in other comprehensive income (loss) resulting from amounts recognised in other comprehensive income (loss).

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No definition available.

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- Definition

Realized gains (losses) on forward exchange contracts.

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Financial risk management (Schedule of Currency Risks) (Details) - Currency risk [Member] $ in Thousands, $ in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) $ / $ $ / $	Sep. 30, 2018 MXN ($)	Sep. 30, 2018 USD ($) $ / $ $ / $	Sep. 30, 2018 CAD ($)	Sep. 30, 2018 MXN ($)	Sep. 30, 2018 CAD ($) $ / $ $ / $	Sep. 30, 2018 MXN ($) $ / $ $ / $
Canadian Dollar [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Approximate impact of exchange rate fluctuations on net loss				$ 523
Approximate impact of exchange rate fluctuations on other comprehensive loss				$ 39
Foreign exchange rates \| $ / $	1.29		1.29			1.29	1.29
Mexican Peso [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Approximate impact of exchange rate fluctuations on net loss					$ 1,331
Approximate impact of exchange rate fluctuations on other comprehensive loss					(57)
Foreign exchange rates \| $ / $	18.81		18.81			18.81	18.81
Cash and Cash Equivalents [Member] \| Canadian Dollar [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income						$ 206
Cash and Cash Equivalents [Member] \| Mexican Peso [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income							$ 133
Trade and other receivables [Member] \| Canadian Dollar [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income						39
Trade and other receivables [Member] \| Mexican Peso [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income							1,871
Trade and Other Payables [Member] \| Canadian Dollar [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income						$ 1,004
Trade and Other Payables [Member] \| Mexican Peso [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income							4,506
Non-Hedge Foreign Exchange Forward Contracts [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Realized gains on forward exchange contracts	$ 100		$ 200
Non-Hedge Foreign Exchange Forward Contracts [Member] \| Mexican Peso [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income							$ 33,700
Risk from currency fluctuations recognized in net earnings or other comprehensive income		$ 44,100			$ 68,900
Foreign exchange rates \| $ / $	21.00		21.00			21.00	21.00
Approximate value of currency expected to be settled in fourth quarter	$ 1,600		$ 1,600
Approximate value of currency expected to be settled in fourth quarter, portion held as fund deposit	100		100
Realized gains on forward exchange contracts	$ 200		$ 100
Foreign Exchange Forward Contracts [Member] \| Mexican Peso [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Risk from currency fluctuations yet to be recognized in net earnings or other comprehensive income							$ 1,800
Foreign exchange rates \| $ / $	18.85		18.85			18.85	18.85