cm:Concept: us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization
       
          
          | Disposal Group, Including Discontinued Operation, Depreciation and Amortization | 
       
       
          
          | us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization | 
       
       
          
          | Amount of depreciation and amortization expense attributable to disposal group, including, but not limited to, discontinued operation. | 
       
       
          
          | cm:Concept | 
       
       
          
          | Monetary (xbrli:monetaryItemType) | 
       
       
          
          | For Period (duration) | 
       
       
          
          | Debit | 
       
       
          
          | false | 
       
       
          
          | us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization |