cm:Level2TextBlock: us-gaap:RevenueRecognitionSalesOfServices
| Revenue Recognition, Sales of Services [Policy Text Block] |
| us-gaap:RevenueRecognitionSalesOfServices |
| Disclosure of accounting policy for revenue recognition for sales of a service. The entity also may disclose how it recognizes cost of sales for such a service transaction and its treatment of any unearned or deferred revenue that arises from the transaction. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RevenueRecognitionSalesOfServices |