cm:Concept: us-gaap:UnbilledChangeOrdersAmountExpectedToBeCollectedWithinOneYear
| Unbilled Change Orders, Amount Expected to be Collected within One Year |
| us-gaap:UnbilledChangeOrdersAmountExpectedToBeCollectedWithinOneYear |
| Amount of unbilled change orders from customers under long-term contracts or programs associated with unpriced change orders or other similar items subject to uncertainty concerning their determination or ultimate realization which is expected to be collected within one year from the balance sheet date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:UnbilledChangeOrdersAmountExpectedToBeCollectedWithinOneYear |