cm:Concept: us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable
       
          
          | Increase (Decrease) in Accounts and Notes Receivable | 
       
       
          
          | us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable | 
       
       
          
          | The increase (decrease) during the reporting period of the sum of amounts due within one year (or one business cycle) from customers for the credit sale of goods and services; and from note holders for outstanding loans. | 
       
       
          
          | cm:Concept | 
       
       
          
          | Monetary (xbrli:monetaryItemType) | 
       
       
          
          | For Period (duration) | 
       
       
          
          | Credit | 
       
       
          
          | false | 
       
       
          
          | us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable |