cm:Concept: us-gaap:AccountsReceivableUnapprovedContractClaimsAmountExpectedToBeCollectedWithinOneYear
       
          
          | Accounts Receivable, Unapproved Contract Claims, Amount Expected to be Collected within One Year | 
       
       
          
          | us-gaap:AccountsReceivableUnapprovedContractClaimsAmountExpectedToBeCollectedWithinOneYear | 
       
       
          
          | The amount of unbilled receivables, which are expected to be collected within one year, from customers under long-term contracts that have not been billed and were not billable at the date of the statement of financial position. | 
       
       
          
          | cm:Concept | 
       
       
          
          | Monetary (xbrli:monetaryItemType) | 
       
       
          
          | As Of (instant) | 
       
       
          
          | Debit | 
       
       
          
          | false | 
       
       
          
          | us-gaap:AccountsReceivableUnapprovedContractClaimsAmountExpectedToBeCollectedWithinOneYear |