cm:Member: us-gaap:DiscontinuedOperationsDisposedOfByMeansOtherThanSaleExchangeMember
| Discontinued Operations, Disposed of by Means Other than Sale, Exchange [Member] |
| us-gaap:DiscontinuedOperationsDisposedOfByMeansOtherThanSaleExchangeMember |
| Component or group of components disposed of in an exchange measured based on the recorded amount of the nonmonetary asset relinquished and representing a strategic shift that has or will have a major effect on operations and financial results. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:DiscontinuedOperationsDisposedOfByMeansOtherThanSaleExchangeMember |