cm:Concept: us-gaap:IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority
| Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority |
| us-gaap:IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority |
| The amount of the additional liability or refund received or expected based on a final settlement with a taxing authority. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority |