cm:Concept: us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwillFairValueDisclosure
| Indefinite-lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure |
| us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwillFairValueDisclosure |
| Fair value portion of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwillFairValueDisclosure |