cm:Concept: us-gaap:FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerSharePlannedSaleInvestmentsNotIdentifiedNumber
| Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Planned Sale, Investments Not Identified, Number |
| us-gaap:FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerSharePlannedSaleInvestmentsNotIdentifiedNumber |
| The total number of all investments, comprising or included in the major category, of those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments) for which the entity has intentions to sell or liquidate, but the specific assets for sale or liquidation have not been identified (for example, the entity intends to sell 10 of its investments in hedge funds, but the individual investments to be sold have not been identified). |
| cm:Concept |
| Decimal (xbrli:decimalItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerSharePlannedSaleInvestmentsNotIdentifiedNumber |