Financial Instruments - Changes in Fair Value Attributable to Changes in Bank'S Own Credit Risk for Financial Liabilities Designated at Fair Value (Detail) - CAD ($) $ in Millions	3 Months Ended
Jul. 31, 2021	Apr. 30, 2021	Jul. 31, 2020	Nov. 01, 2020
Disclosure of detailed information about financial instruments [line items]
Carrying value				$ 2,928
Senior note liabilities [member]
Disclosure of detailed information about financial instruments [line items]
Contractual maturity amount	$ 21,057	$ 20,056	$ 17,486
Carrying value	21,961	20,406	17,522
Difference between carrying value and contractual maturity amount	(904)	(350)	(36)
Changes in fair value for the period attributable to changes in own credit risk recorded in other comprehensive income	72	(140)	(585)
Cumulative changes in fair value due to changes in own credit risk	$ (705)	$ (777)	$ (248)

Contractual maturity amount of deposit note liabilities.

No definition available.

Name:	bns_ContractualMaturityAmountOfDepositNoteLiabilities
Namespace Prefix:	bns_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The accumulated increase (decrease) in the fair value of financial liabilities that is attributable to changes in the credit risk of the liabilities. [Refer: Credit risk [member]; Market risk [member]; Increase (decrease) in fair value of financial liability, attributable to changes in credit risk of liability]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 10
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_10_a&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 10A
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_10A_a&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- Definition

The increase (decrease) in the fair value of a financial liability that is attributable to changes in the credit risk of that liability. [Refer: Credit risk [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 10A
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_10A_a&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2021-01-01
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 10
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_10_a&doctype=Standard&book=b
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_ChangesInFairValueOfFinancialLiabilityAttributableToChangesInCreditRiskOfLiability
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount by which the carrying amount of a financial liability is more (less) than the amount that the entity would be contractually required to pay at maturity to the holder of the obligation. [Refer: Carrying amount [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 10
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_10_b&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 10A
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_10A_b&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_DifferenceBetweenCarryingAmountOfFinancialLiabilityAndAmountContractuallyRequiredToPayAtMaturityToHolderOfObligation
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- 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

Name:	ifrs-full_DisclosureOfFinancialInstrumentsLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of financial liabilities at fair value through profit or loss that were designated as such upon initial recognition or subsequently. [Refer: At fair value [member]; Financial liabilities at fair value through profit or loss]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 8
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_8_e&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- Details

Name:	ifrs-full_ClassesOfLiabilitiesAxis=bns_SeniorNoteLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: