cm:Member: us-gaap:DefinedBenefitPlanDerivativeMember
| Defined Benefit Plan, Derivative [Member] |
| us-gaap:DefinedBenefitPlanDerivativeMember |
| Financial instrument or other contract with one or more underlyings, notional amount or payment provision or both; can be settled net by means outside contract or delivery of asset; and with minimal or no initial net investment, in which defined benefit plan asset is invested. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:DefinedBenefitPlanDerivativeMember |