cm:Concept: us-gaap:ContractsReceivableClaimsAndUncertainAmountsExpectedToBeCollectedAfterOneYear
| Contracts Receivable, Claims and Uncertain Amounts, Expected to be Collected after Next Twelve Months |
| us-gaap:ContractsReceivableClaimsAndUncertainAmountsExpectedToBeCollectedAfterOneYear |
| Amount of billed or unbilled claims or similar items subject to uncertainty concerning their determination or ultimate realization under long-term contracts that are expected to be collected after the next 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:ContractsReceivableClaimsAndUncertainAmountsExpectedToBeCollectedAfterOneYear |