cm:Concept: us-gaap:DerivativeInstrumentsInHedgesAssetsAtFairValue
| Derivative Instruments in Hedges, Assets, at Fair Value |
| us-gaap:DerivativeInstrumentsInHedgesAssetsAtFairValue |
| Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:DerivativeInstrumentsInHedgesAssetsAtFairValue |