cm:Member: us-gaap:DebenturesSubjectToMandatoryRedemptionMember
| Debentures Subject to Mandatory Redemption [Member] |
| us-gaap:DebenturesSubjectToMandatoryRedemptionMember |
| A type of debt instrument that embodies an unconditional obligation requiring the issuer to redeem the securities by transferring assets at a specified or determinable date (or dates) or upon an event that is certain to occur, that is not secured by physical assets or other collateral. Debentures are backed only by the general creditworthiness and reputation of the issuer. Both corporations and governments frequently issue this type of bond to secure capital. Like other types of bonds, debentures are documented in an indenture. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:DebenturesSubjectToMandatoryRedemptionMember |