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 |