cm:Concept: us-gaap:UnrecordedUnconditionalPurchaseObligationPeriodQuantityPurchased
| Unrecorded Unconditional Purchase Obligation, Period Quantity Purchased |
| us-gaap:UnrecordedUnconditionalPurchaseObligationPeriodQuantityPurchased |
| The number of units that have been purchased during the period, in connection with an unconditional purchase obligation that has not been recognized for financial reporting purposes. |
| cm:Concept |
| Decimal (xbrli:decimalItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:UnrecordedUnconditionalPurchaseObligationPeriodQuantityPurchased |