cm:Concept: us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets
| Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets |
| us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets |
| Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets |