cm:Concept: us-gaap:FairValueMeasurementAccountingPolicyException
| Fair Value Measurement, Accounting Policy Exception [true false] |
| us-gaap:FairValueMeasurementAccountingPolicyException |
| Indicates (true false) whether fair value of group of financial assets, liabilities and nonfinancial items accounted for as derivatives was measured based on price received to sell net long position or paid to transfer net short position for particular risk exposure in orderly transaction at measurement date under current market condition. |
| cm:Concept |
| Yes/No (xbrli:booleanItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:FairValueMeasurementAccountingPolicyException |