cm:Concept: us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths
| Finite-Lived Intangible Assets, Amortization Expense, Next Rolling Twelve Months |
| us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths |
| Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized in 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:FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths |