Capital Management - Summary of Capitalization and Ratio (Detail) - CAD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Capitalisation [Abstract]
Long-term debt	$ 1,427,181	$ 1,706,253
Shareholders’ equity	1,527,432	1,557,752
Total capitalization	$ 2,954,613	$ 3,264,005
Long-term debt to long-term debt plus equity ratio	0.48%	0.52%

The amount of equity attributable to the owners of the parent. This specifically excludes non-controlling interest.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 54
-Subparagraph r
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_54_r&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_EquityAttributableToOwnersOfParent
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant