cm:Concept: us-gaap:BusinessCombinationContingentConsiderationArrangementsBasisForAmount
       
          
          | Business Combination, Contingent Consideration Arrangements, Basis for Amount | 
       
          
          | us-gaap:BusinessCombinationContingentConsiderationArrangementsBasisForAmount | 
       
          
          | For contingent consideration arrangements recognized in connection with a business combination, this element represents a description of the basis for determining the amount of the payment recorded. | 
       
          
          | cm:Concept | 
       
          
          | Text/String (xbrli:stringItemType) | 
       
          
          | For Period (duration) | 
       
          
          | (no balance type) | 
       
          
          | false | 
       
          
          | us-gaap:BusinessCombinationContingentConsiderationArrangementsBasisForAmount |