PER SHARE AMOUNTS - Narrative (Details) - CAD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Earnings per share [abstract]
Net profit (loss)	$ (146,339)	$ (91,363)

The profit (loss) attributable to ordinary equity holders of the parent equity. [Refer: Profit (loss)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2018-01-01
-Paragraph 70
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=33&date=2018-03-01&anchor=para_70_a&doctype=Standard
-URIDate 2018-03-16

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