cm:Table: us-gaap:UnrecordedUnconditionalPurchaseObligationTable
| Unrecorded Unconditional Purchase Obligation [Table] |
| us-gaap:UnrecordedUnconditionalPurchaseObligationTable |
| Describes each unrecorded unconditional purchase obligation arrangement to purchase goods and services that extend over multiple periods, any assets pledged to secure payment, and the fixed or determinable amount of payments due in each of the next five years and thereafter. |
| cm:Table |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:UnrecordedUnconditionalPurchaseObligationTable |