Property, Plant and Equipment - Additional Information (Detail) - CAD ($) $ in Millions	Jan. 31, 2019	Jan. 31, 2018	Feb. 01, 2017
Disclosure of detailed information about property, plant and equipment [abstract]
Assets under development	$ 81.7	$ 65.5	$ 51.8

The amount of expenditures recognised in the carrying amount of an item of property, plant and equipment in the course of its construction. [Refer: Carrying amount [member]; Property, plant and equipment]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2018-01-01
-Paragraph 74
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=16&date=2018-03-01&anchor=para_74_b&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_PropertyPlantAndEquipmentExpendituresRecognisedForConstructions
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant