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Loans - Additional Information (Detail) - CAD ($) $ in Millions | 12 Months Ended
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Oct. 31, 2025 | Oct. 31, 2024
Disclosure of detailed information about borrowings [line items] |  |
Stage 2 performing loans measured at stage 1 would be lower than total recognized IFRS 9 ECL | $ 938 | $ 854
Downside Scenario [Member] |  |
Disclosure of detailed information about borrowings [line items] |  |
ECL expected value | $ 853 | 737
Probability weighting percentage | 100.00% |
Base Scenario [Member] |  |
Disclosure of detailed information about borrowings [line items] |  |
ECL expected value | $ 420 | 246
Probability weighting percentage | 100.00% |
Modified Loans [member] | Stage 1 [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Gross carrying amount of previously modified stage 2 or stage 3 loans that have returned to stage 1 | $ 327 | 274
Modified Loans [member] | Stage 2 [member] |  |
Disclosure of detailed information about borrowings [line items] |  |
Loans classified as stage 2 or 3, amortized cost | $ 309 | $ 655

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- Definition Allowance account for credit losses of financial assets higher (lower) from total recognized IFRS Nine expected credit losses. + References No definition available. + Details
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- Definition Higher or lower expected credit losses if stage two performing loans were measured using stage one expected credit losses. + References No definition available. + Details
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- Definition Impaired loans at amortised cost. + References No definition available. + Details
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- Definition Probability weighting percentage. + References No definition available. + Details
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Namespace Prefix: | cm_
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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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- Details
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- Details
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Balance Type: |
Period Type: |

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- Details
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Balance Type: |
Period Type: |

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- Details
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- Details
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