cm:Member: us-gaap:AccumulatedNetGainLossFromCashFlowHedgesAttributableToNoncontrollingInterestMember
| Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member] |
| us-gaap:AccumulatedNetGainLossFromCashFlowHedgesAttributableToNoncontrollingInterestMember |
| Accumulated other comprehensive income (loss) resulting from gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges, attributable to the noncontrolling interest. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:AccumulatedNetGainLossFromCashFlowHedgesAttributableToNoncontrollingInterestMember |