cm:Concept: us-gaap:ObligationWithJointAndSeveralLiabilityArrangementRecourseProvisionDescription
| Obligation with Joint and Several Liability Arrangement, Recourse Provision, Description |
| us-gaap:ObligationWithJointAndSeveralLiabilityArrangementRecourseProvisionDescription |
| Description of the nature of a recourse provision that would enable recovery from other entities of the amounts paid, including, but not limited to, limitations on recoverable amounts. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ObligationWithJointAndSeveralLiabilityArrangementRecourseProvisionDescription |