cm:Member: us-gaap:AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember
       
          
          | Accumulated Gain (Loss), Net, Cash Flow Hedge, Noncontrolling Interest [Member] | 
       
       
          
          | us-gaap:AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember | 
       
       
          
          | Accumulated other comprehensive income (loss) from gain (loss) of derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness, attributable to noncontrolling interest. | 
       
       
          
          | cm:Member | 
       
       
          
          | [Member] (nonnum:domainItemType) | 
       
       
          
          | For Period (duration) | 
       
       
          
          | (no balance type) | 
       
       
          
          | true | 
       
       
          
          | us-gaap:AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember |