cm:Concept: us-gaap:LongTermPurchaseCommitmentMinimumQuantityRequired
| Long-term Purchase Commitment, Minimum Quantity Required |
| us-gaap:LongTermPurchaseCommitmentMinimumQuantityRequired |
| Number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences. |
| cm:Concept |
| Integer (xbrli:integerItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:LongTermPurchaseCommitmentMinimumQuantityRequired |