Critical Accounting Estimates and Judgments - Additional Information (Detail)	Apr. 30, 2018
Disclosure of changes in accounting estimates [abstract]
Actuarial assumption of expected rates of inflation	3.50%
Percentage of reasonably possible decrease in actuarial assumption	8.00%

The expected rate of inflation that is used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2017-01-01
-Paragraph 144
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_144&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_ActuarialAssumptionOfExpectedRatesOfInflation
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant