cm:Member: us-gaap:SubordinatedDebenturesSubjectToMandatoryRedemptionMember
| Subordinated Debentures Subject to Mandatory Redemption [Member] |
| us-gaap:SubordinatedDebenturesSubjectToMandatoryRedemptionMember |
| A debt instrument that embodies 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. This instrument is not secured by physical assets or other collateral and is backed only by the general creditworthiness and reputation of the issuer. Subordinated debentures are debt securities with a current interest rate that is senior in liquidation preference to all equity but junior to secured debt. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:SubordinatedDebenturesSubjectToMandatoryRedemptionMember |