cm:Concept: us-gaap:DeferredRevenueDescription
| Deferred Revenue, Description |
| us-gaap:DeferredRevenueDescription |
| Description of the transaction or nature of business giving rise to deferred revenue or unearned revenue, other than annual membership fees. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DeferredRevenueDescription |