cm:Level2TextBlock: us-gaap:MinimumGuaranteesPolicy
| Minimum Guarantees, Policy [Policy Text Block] |
| us-gaap:MinimumGuaranteesPolicy |
| Disclosure of accounting policy for minimum guarantees, including the nature of each guarantee given to contract holders under long-duration contracts, and the methods of determining the amounts of the guarantees reflected as liabilities in the balance sheet or disclosed. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:MinimumGuaranteesPolicy |