cm:Concept: us-gaap:IntangibleAssetsNetIncludingGoodwill
       
          
          | Intangible Assets, Net (Including Goodwill) | 
       
          
          | us-gaap:IntangibleAssetsNetIncludingGoodwill | 
       
          
          | Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance. | 
       
          
          | cm:Concept | 
       
          
          | Monetary (xbrli:monetaryItemType) | 
       
          
          | As Of (instant) | 
       
          
          | Debit | 
       
          
          | false | 
       
          
          | us-gaap:IntangibleAssetsNetIncludingGoodwill |