cm:Member: us-gaap:TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain
| Financial Instruments [Domain] |
| us-gaap:TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain |
| Instrument or contract that imposes a contractual obligation to deliver cash or another financial instrument or to exchange other financial instruments on potentially unfavorable terms and conveys a contractual right to receive cash or another financial instrument or to exchange other financial instruments on potentially favorable terms. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain |