cm:Concept: us-gaap:ContractReceivableDueInNextRollingTwelveMonths
| Contract Receivable, Due in Next Rolling Twelve Months |
| us-gaap:ContractReceivableDueInNextRollingTwelveMonths |
| Amount billed to customers under long-term contracts or programs to be collected in the next rolling twelve months following the latest balance sheet. Excludes amounts due that have been withheld because of retainage provisions in a contract. For 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:ContractReceivableDueInNextRollingTwelveMonths |