Earnings Per Share - Summary of Earnings Per Share (Parenthetical) (Detail) - $ / shares shares in Millions	3 Months Ended
Jan. 31, 2020	Jan. 31, 2019
Earnings per share [abstract]
Average outstanding options excluded from calculation of diluted earnings per share	0.0	1.8
Weighted-average exercise price of average outstanding options excluded from the calculation of diluted earnings per share		$ 72.64

The weighted average exercise price of share options outstanding in a share-based payment arrangement. [Refer: Weighted average [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 45
-Subparagraph b
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_45_b_i&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 45
-Subparagraph b
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_45_b_vi&doctype=Standard
-URIDate 2019-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant