cm:Concept: us-gaap:SharesSubjectToMandatoryRedemptionSettlementTermsImpactOfChangesInFairValueOfSharesOnAmount
| Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Impact of Changes in Fair Value of Shares on Amount |
| us-gaap:SharesSubjectToMandatoryRedemptionSettlementTermsImpactOfChangesInFairValueOfSharesOnAmount |
| Increase (decrease) in settlement amount from change in fair value of issuer's equity shares. For example, but not limited to, issuer obligated to pay an additional Y dollars in cash for each $1 decrease in the fair value of one share. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:SharesSubjectToMandatoryRedemptionSettlementTermsImpactOfChangesInFairValueOfSharesOnAmount |