CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED BALANCE SHEETS
Common shares issued	235,025,507	232,793,335
Common shares held in trust	566,910	542,894

The number of shares issued by the entity.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 106
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_106_d&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_NumberOfSharesIssued
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant