cm:Concept: us-gaap:ContractsReceivableClaimsAndUncertainAmountsExpectedToBeCollectedAfterNextRollingTwelveMonths
| Contracts Receivable, Claims and Uncertain Amounts, Expected to be Collected after Next Rolling Twelve Months |
| us-gaap:ContractsReceivableClaimsAndUncertainAmountsExpectedToBeCollectedAfterNextRollingTwelveMonths |
| 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 rolling twelve months following the latest balance sheet. 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:ContractsReceivableClaimsAndUncertainAmountsExpectedToBeCollectedAfterNextRollingTwelveMonths |