cm:Member: us-gaap:CumulativePreferredStockSubjectToMandatoryRedemptionMember
| Cumulative Preferred Stock Subject to Mandatory Redemption [Member] |
| us-gaap:CumulativePreferredStockSubjectToMandatoryRedemptionMember |
| 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, which 1) provide a specific dividend that is paid before any dividends are paid to common stock holders, 2) take precedence over common stock in the event of a liquidation, 3) do not enjoy any of the voting rights of common stockholders and 4 have a provision stipulating that if one or more dividends are omitted (in arrearage) because of insufficient earnings or any other reason, these dividends will accumulate until they are paid to shareholders. Cumulative preferred stocks have seniority over common stocks and a common stock dividend cannot be paid until all cumulative preferred dividends are current. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:CumulativePreferredStockSubjectToMandatoryRedemptionMember |