cm:Concept: us-gaap:LongTermDebtPercentageBearingFixedInterestRate
       
          
          | Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate | 
       
       
          
          | us-gaap:LongTermDebtPercentageBearingFixedInterestRate | 
       
       
          
          | The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate. | 
       
       
          
          | cm:Concept | 
       
       
          
          | Percent (num:percentItemType) | 
       
       
          
          | As Of (instant) | 
       
       
          
          | (no balance type) | 
       
       
          
          | false | 
       
       
          
          | us-gaap:LongTermDebtPercentageBearingFixedInterestRate |