cm:Concept: us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates
| Payments to Acquire Businesses and Interest in Affiliates |
| us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates |
| The cash outflow associated with the acquisition of a controlling interest in another entity or an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, joint venture or equity method investment). |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:PaymentsToAcquireBusinessesAndInterestInAffiliates |