cm:Concept: us-gaap:IncreaseDecreaseInAccruedCostOfOilAndGasReclamation
       
          
          | Increase (Decrease) in Accrued Cost of Oil and Gas Reclamation | 
       
       
          
          | us-gaap:IncreaseDecreaseInAccruedCostOfOilAndGasReclamation | 
       
       
          
          | The increase (decrease) during the reporting period in accrued costs that represent future cash outlays for restoration and reclamation of oil and gas producing properties. | 
       
       
          
          | cm:Concept | 
       
       
          
          | Monetary (xbrli:monetaryItemType) | 
       
       
          
          | For Period (duration) | 
       
       
          
          | Credit | 
       
       
          
          | false | 
       
       
          
          | us-gaap:IncreaseDecreaseInAccruedCostOfOilAndGasReclamation |