cm:Level1TextBlock: us-gaap:MinimumGuaranteesNetAmountAtRiskDisclosure
| Minimum Guarantees, Net Amount at Risk Disclosure [Text Block] |
| us-gaap:MinimumGuaranteesNetAmountAtRiskDisclosure |
| The entire disclosure for contracts with guaranteed benefits in excess of the current account balance. Disclose the amount of liability reported for additional insurance benefits, annuitization benefits and other minimum guarantees; the net amount at risk; and the weighted average attained age of contract holders, by type of guarantee and by type of benefit, as of the most recent balance sheet date. |
| cm:Level1TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:MinimumGuaranteesNetAmountAtRiskDisclosure |