cm:Member: us-gaap:SecuritiesSubjectToMandatoryRedemptionMember
| Securities Subject to Mandatory Redemption [Member] |
| us-gaap:SecuritiesSubjectToMandatoryRedemptionMember |
| Securities issued in the form of shares that embody an unconditional obligation requiring the issuer to redeem the securities by transferring the assets at a specified or determinable date (or dates) or upon an event that is certain to occur. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:SecuritiesSubjectToMandatoryRedemptionMember |