cm:Level2TextBlock: us-gaap:AllocationsToPolicyholdersPolicies
| Allocations to Policyholders, Policies [Policy Text Block] |
| us-gaap:AllocationsToPolicyholdersPolicies |
| Disclosure of accounting policy for determining amounts of income and expenses allocated to policyholders and contract holders, excluding the method for determining dividends payable to policyholders and accounting policies pertaining to separate accounts for variable annuity contracts. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:AllocationsToPolicyholdersPolicies |