cm:Concept: us-gaap:CommodityContractAssetNoncurrent
| Commodity Contract Asset, Noncurrent |
| us-gaap:CommodityContractAssetNoncurrent |
| Carrying amount as of the balance sheet date of the asset arising from commodity contracts such as futures contracts tied to the movement of a particular commodity, which are expected to be converted into cash or otherwise disposed of after a year or beyond the normal operating cycle, if longer. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:CommodityContractAssetNoncurrent |