cm:Concept: us-gaap:DeferredIncomeTaxesAndOtherTaxReceivableCurrent
| Deferred Income Taxes and Other Tax Receivable, Current |
| us-gaap:DeferredIncomeTaxesAndOtherTaxReceivableCurrent |
| Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and other tax receivables expected to be realized or consumed within one year or operating cycle, if longer. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:DeferredIncomeTaxesAndOtherTaxReceivableCurrent |