cm:Concept: us-gaap:ApplicabilityAndImpactOfEnvironmentalLaws
| Applicability and Impact of Environmental Laws |
| us-gaap:ApplicabilityAndImpactOfEnvironmentalLaws |
| The general applicability and impact of environmental laws and regulations upon the entity's business and how the existence of such laws and regulations may continue to give rise to loss contingencies for future environmental remediation. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ApplicabilityAndImpactOfEnvironmentalLaws |