cm:Concept: us-gaap:RevenueInformationUsedToAllocateTransactionPrice
| Revenue, Information Used to Allocate Transaction Price |
| us-gaap:RevenueInformationUsedToAllocateTransactionPrice |
| Description of methods, inputs, and assumptions used to allocate transaction price. Includes, but not is limited to, estimating standalone selling price of promised good or service and allocating discount and variable consideration to specific part of contract. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RevenueInformationUsedToAllocateTransactionPrice |