cm:Member: us-gaap:GainContingencyNatureDomain
| Gain Contingency, Nature [Domain] |
| us-gaap:GainContingencyNatureDomain |
| Describes any existing condition, situation, or set of circumstances involving uncertainty as of the balance sheet date (or before issuance of the financial statements) that might result in a gain, typically reflecting care to avoid misleading implications as to the likelihood of realization. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:GainContingencyNatureDomain |