cm:Concept: us-gaap:SubsidiaryOrEquityMethodInvesteeDeferredIncomeTaxProvisionOnCumulativeGainLossRecognizedAmount
| Subsidiary or Equity Method Investee, Deferred Income Tax Provision on Gain (Loss) Recognized, Amount |
| us-gaap:SubsidiaryOrEquityMethodInvesteeDeferredIncomeTaxProvisionOnCumulativeGainLossRecognizedAmount |
| The amount provided for deferred income taxes in relation to any gain (loss) recognized in income of the entity resulting from the issuance of shares by a subsidiary or equity method investee. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:SubsidiaryOrEquityMethodInvesteeDeferredIncomeTaxProvisionOnCumulativeGainLossRecognizedAmount |