Financial Instruments-Risk Management - Summary of Risk Categories of Borrower Internal Grades (Parenthetical) (Detail) - CAD ($) $ in Millions	Oct. 31, 2021	Oct. 31, 2020
Disclosure of detailed information about financial instruments [abstract]
Loss protection related to derivatives transactions, net of related collateral excluded	$ 3.5	$ 3.5

Derivatives transactions net of related collateral excluded.

No definition available.

Name:	bns_DerivativesTransactionsNetOfRelatedCollateralExcluded
Namespace Prefix:	bns_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant