cm:Level3TextBlock: us-gaap:ScheduleOfCapitalUnitsTextBlock
       
          
          | Schedule of Capital Units [Table Text Block] | 
       
          
          | us-gaap:ScheduleOfCapitalUnitsTextBlock | 
       
          
          | Tabular disclosure of an entity's capital units or capital shares, including the value of capital units or capital shares, units authorized, units outstanding and other information necessary to a fair presentation. | 
       
          
          | cm:Level3TextBlock | 
       
          
          | Text Block (HTML) (nonnum:textBlockItemType) | 
       
          
          | For Period (duration) | 
       
          
          | (no balance type) | 
       
          
          | false | 
       
          
          | us-gaap:ScheduleOfCapitalUnitsTextBlock | 
       
          
          | CapitalUnits |