cm:Table: us-gaap:TradingActivitiesGainLossByTypeTable
| Trading Activities, Gain and Losses, by Type, by Income Statement Location [Table] |
| us-gaap:TradingActivitiesGainLossByTypeTable |
| Schedule of gains and losses on trading activities (including both derivative and nonderivative instruments) recognized in the statement of financial performance by statement location, separately by major types of items (such as fixed income/interest rates, foreign exchange, equity, commodity, and credit). |
| cm:Table |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:TradingActivitiesGainLossByTypeTable |