cm:Concept: us-gaap:DisposalGroupIncludingDiscontinuedOperationForeignCurrencyTranslationGainsLosses
| Disposal Group, Including Discontinued Operation, Foreign Currency Translation Gains (Losses) |
| us-gaap:DisposalGroupIncludingDiscontinuedOperationForeignCurrencyTranslationGainsLosses |
| Amount of foreign currency translation gain (loss) in the disposal group, including discontinued operation, recognized in the statement of income as a result of the sale or complete or substantially complete liquidation of an investment in a foreign entity. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:DisposalGroupIncludingDiscontinuedOperationForeignCurrencyTranslationGainsLosses |