XML 234 R191.htm IDEA: XBRL DOCUMENT v3.25.3

Related Party Transactions - Additional Information (Detail) - Key management personnel directors and their close family members [member] - CAD ($) $ in Millions	12 Months Ended
	Oct. 31, 2025	Oct. 31, 2024
Disclosure of transactions between related parties [line items]
Loans to related party	$ 23	$ 19
Allowance for credit losses	$ 0	$ 0

X

- Definition

The cash outflow for loans and advances made to related parties. [Refer: Total for all related parties [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2024-01-01
-Paragraph 16
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2024-en-r&anchor=para_16&doctype=Standard
-URIDate 2024-03-27

+ Details

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

X

- Definition

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

+ References

No definition available.

+ Details

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

X

- Definition

The amount of provisions for doubtful debts related to the amount of outstanding balances in related party transactions. [Refer: Provisions]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
-Paragraph 18
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=24&code=ifrs-tx-2024-en-r&anchor=para_18_c&doctype=Standard
-URIDate 2024-03-27

+ Details

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

X

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=bmo_KeyManagementPersonnelDirectorsAndTheirCloseFamilyMembersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: