cm:Level3TextBlock: us-gaap:CostIncurredInOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivitiesDisclosureTextBlock
       
          
          | Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure [Table Text Block] | 
       
       
          
          | us-gaap:CostIncurredInOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivitiesDisclosureTextBlock | 
       
       
          
          | Tabular disclosure of the aggregate of costs (whether the costs are capitalized or charged to expense at the time they are incurred ) incurred for the year in oil and gas property acquisition, exploration and development activities. | 
       
       
          
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          | Text Block (HTML) (nonnum:textBlockItemType) | 
       
       
          
          | For Period (duration) | 
       
       
          
          | (no balance type) | 
       
       
          
          | false | 
       
       
          
          | us-gaap:CostIncurredInOilAndGasPropertyAcquisitionExplorationAndDevelopmentActivitiesDisclosureTextBlock |