cm:Concept: us-gaap:NondebtorReorganizationItemsNetGainLossOnSettlementOfOtherClaims1
| Nondebtor Reorganization Items, Net (Gain) Loss on Settlement of Other Claims |
| us-gaap:NondebtorReorganizationItemsNetGainLossOnSettlementOfOtherClaims1 |
| Amount of gain (loss) on settlement of other claims for entities not in bankruptcy, reported as a reorganization item. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:NondebtorReorganizationItemsNetGainLossOnSettlementOfOtherClaims1 |