cm:Concept: us-gaap:DeferredCompensationArrangementWithIndividualContributionsByEmployer
| Deferred Compensation Arrangement with Individual, Contributions by Employer |
| us-gaap:DeferredCompensationArrangementWithIndividualContributionsByEmployer |
| Amount of contributions made by employer into fund established for purposes of making future disbursement to individual in accordance with deferred compensation arrangement. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:DeferredCompensationArrangementWithIndividualContributionsByEmployer |