cm:Concept: us-gaap:NonmonetaryTransactionBasisOfAccountingForAssetsTransferred
| Nonmonetary Transaction, Basis of Accounting for Assets Transferred |
| us-gaap:NonmonetaryTransactionBasisOfAccountingForAssetsTransferred |
| Disclosure of the accounting treatment and method of measurement for nonmonetary exchanges of assets or liabilities or related to a transfer of nonmonetary assets for which the Entity receives no assets in return. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:NonmonetaryTransactionBasisOfAccountingForAssetsTransferred |