cm:Member: us-gaap:WarrantsAndRightsSubjectToMandatoryRedemptionMember
| Warrants and Rights Subject to Mandatory Redemption [Member] |
| us-gaap:WarrantsAndRightsSubjectToMandatoryRedemptionMember |
| Warrants and rights that embody an unconditional obligation requiring the issuer to redeem the instrument by transferring its assets at a specified or determinable date (or dates) or upon an event certain to occur. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:WarrantsAndRightsSubjectToMandatoryRedemptionMember |