cm:Member: us-gaap:FairValueInputsLevel12And3Member
| Fair Value, Inputs, Level 1, 2 and 3 [Member] |
| us-gaap:FairValueInputsLevel12And3Member |
| Fair value measurement input including quoted price in active market for identical asset or liability reporting entity can access at measurement date (level 1), input other than quoted price included within level 1 either directly or indirectly observable for asset or liability (level 2) and unobservable input reflecting entity's own assumption (level 3). |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:FairValueInputsLevel12And3Member |