Investments in Joint Ventures and Associates - Additional Information (Detail) - CAD	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Disclosure of joint ventures and associates [line items]
Dividend paid	CAD 0	CAD 0
PAE Limited [member]
Disclosure of joint ventures and associates [line items]
Percentage of investment in joint venture	40.00%
ESH MWH Limited. [member]
Disclosure of joint ventures and associates [line items]
Percentage of investment in joint venture	50.00%

The proportion of ownership interest in a joint venture attributable to the entity. [Refer: Joint ventures [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2017-01-01
-Paragraph 17
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=27&date=2017-03-01&anchor=para_17_b_iii&doctype=Standard
-URIDate 2017-03-09

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2017-01-01
-Paragraph 16
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=27&date=2017-03-01&anchor=para_16_b_iii&doctype=Standard
-URIDate 2017-03-09

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2017-01-01
-Paragraph 21
-Subparagraph a
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2017-03-01&anchor=para_21_a_iv&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_ProportionOfOwnershipInterestInJointVenture
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration