cm:Member: us-gaap:VariableIncomeInterestRateMember
| Variable Income Interest Rate [Member] |
| us-gaap:VariableIncomeInterestRateMember |
| Trading in a derivative or nonderivative instrument that provides a fluctuating return in the form of periodic payments of interest typically based on movement of a benchmark rate (for example, US Federal Funds Rate, LIBOR), and eventual return of principal at maturity. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:VariableIncomeInterestRateMember |