cm:Concept: us-gaap:UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedAfterOneYear
| Unbilled Receivables, Not Billable, Amount Expected to be Collected after Next Twelve Months |
| us-gaap:UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedAfterOneYear |
| Amount of receivables under long-term contracts that have not been billed and were not billable 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:UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedAfterOneYear |