cm:Concept: us-gaap:EquityMethodInvestmentDeferredGainOnSale
| Equity Method Investment, Deferred Gain on Sale |
| us-gaap:EquityMethodInvestmentDeferredGainOnSale |
| This element represents disclosure of the amount of gain which has been deferred as the result of the sale of a business or operating assets to a highly leveraged entity which deferred gain has been reflected in the accompanying statement of financial position as reduction from the related asset. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:EquityMethodInvestmentDeferredGainOnSale |