cm:Concept: us-gaap:UnrecordedUnconditionalPurchaseObligationMinimumQuantityRequired
| Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required |
| us-gaap:UnrecordedUnconditionalPurchaseObligationMinimumQuantityRequired |
| The minimum number of units that must be purchased, in connection with an unconditional purchase obligation that has not been recognized for financial reporting purposes. |
| cm:Concept |
| Decimal (xbrli:decimalItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:UnrecordedUnconditionalPurchaseObligationMinimumQuantityRequired |