Designated Accounting Hedges - Summary of Items Designated as Hedged Items (Parenthetical) (Detail) - Discontinued operations [member] - CAD ($) $ in Millions	Oct. 31, 2025	Oct. 31, 2024
Disclosure of detailed information about hedged items [line items]
AOCI related to discontinued cash flow hedges	$ 544	$ (198)
Accumulated fair value hedge adjustment remaining in statement of financial statement for hedged item that ceased to be adjusted for net assets liabilities	$ 126
Accumulated fair value hedge net liability adjustment		$ 286

Accumulated fair value hedge adjustment remaining in statement of financial statement for hedged item that ceased to be adjusted for net assets liabilities.

No definition available.

+ Details

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Namespace Prefix:	cm_
Data Type:	xbrli:monetaryItemType
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- Definition

The accumulated amount of fair value hedge adjustment remaining in the statement of financial position for a hedged item that is a financial liability measured at amortised cost and has ceased to be adjusted for hedging gains and losses. [Refer: Financial liabilities at amortised cost; Hedged items [domain]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 24B
-Subparagraph a
-Clause v
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_24B_a_v&doctype=Standard
-URIDate 2024-03-27

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

A component of equity representing the reserve of cash flow hedges in relation to hedging relationships for which hedge accounting is no longer applied. [Refer: Reserve of cash flow hedges]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 24B
-Subparagraph b
-Clause iii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_24B_b_iii&doctype=Standard
-URIDate 2024-03-27

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Details

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