cm:Abstract: us-gaap:MovementInStandardAndExtendedProductWarrantyIncreaseDecreaseRollForward
       
          
          | Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward] | 
       
          
          | us-gaap:MovementInStandardAndExtendedProductWarrantyIncreaseDecreaseRollForward | 
       
          
          | A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. | 
       
          
          | cm:Abstract | 
       
          
          | Text/String (xbrli:stringItemType) | 
       
          
          | For Period (duration) | 
       
          
          | (no balance type) | 
       
          
          | true | 
       
          
          | us-gaap:MovementInStandardAndExtendedProductWarrantyIncreaseDecreaseRollForward |