Financial risk management and financial instruments - Currency risk (Details) - Currency rate risk $ in Thousands	May 31, 2019 CAD ($)
Financial risk management and financial instruments
Percentage change in foreign exchange rate which will result in unrealized gain or loss	1.00%
Unrealized gain or loss by 1% change in the foreign exchange rate	$ 4,000

The amount of risk exposure associated with financial instruments with a shared characteristic that identifies a concentration of risks. [Refer: Financial instruments, class [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2018-01-01
-Paragraph B8
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_B8_c&doctype=Appendix&seq=2
-URIDate 2018-03-16

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant