cm:Concept: us-gaap:ContractReceivableRetainageDueThreeToFourYears
       
          
          | Contract Receivable Retainage, Year Four | 
       
       
          
          | us-gaap:ContractReceivableRetainageDueThreeToFourYears | 
       
       
          
          | Amount billed to customers under long-term contracts or programs that have been withheld because of retainage provisions in a contract to be collected in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. | 
       
       
          
          | cm:Concept | 
       
       
          
          | Monetary (xbrli:monetaryItemType) | 
       
       
          
          | As Of (instant) | 
       
       
          
          | Debit | 
       
       
          
          | false | 
       
       
          
          | us-gaap:ContractReceivableRetainageDueThreeToFourYears |