cm:Level1TextBlock: us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock
       
          
          | Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] | 
       
       
          
          | us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock | 
       
       
          
          | The entire disclosure related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component. | 
       
       
          
          | cm:Level1TextBlock | 
       
       
          
          | Text Block (HTML) (nonnum:textBlockItemType) | 
       
       
          
          | For Period (duration) | 
       
       
          
          | (no balance type) | 
       
       
          
          | false | 
       
       
          
          | us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock | 
       
       
          
          | DisposalGroupsIncludingDiscontinuedOperationsDisclosure |