Post-Employment Benefits - Summary of Assumed Health-care Cost Trend Rates (Detail) - Canada plan [member] - Actuarial assumption of medical cost trend rates [member]	12 Months Ended
Oct. 31, 2020	Oct. 31, 2019
Disclosure of defined benefit plans [line items]
Health-care cost trend rates assumed for next year	5.20%	5.30%
Rate to which the cost trend rate is assumed to decline	4.00%	4.00%
Year that the rate reaches the ultimate trend rate	2040	2040

Actuarial assumption of year rate reach ultimate trend rate.

No definition available.

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- Definition

Medical cost trend rate used as significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2019-01-01
-Paragraph 144
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-URIDate 2019-03-27

+ Details

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

+ Details

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- Definition

The reasonably possible percentage of the decrease in the actuarial assumption used to determine the present value of defined benefit obligation. [Refer: Actuarial assumptions [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2019-01-01
-Paragraph 145
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2019-en-r&anchor=para_145_a&doctype=Standard
-URIDate 2019-03-27

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- Details

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- Details

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