| Standard label: | Oil and Gas Properties Policy [Policy Text Block] |
| Name: | us-gaap:OilAndGasPropertiesPolicyPolicyTextBlock |
| Documentation: | Disclosure of accounting policy for oil and gas property which may include the basis of such assets, depreciation methods used and estimated useful lives, the entity's capitalization policy, including its accounting treatment for costs incurred for repairs and maintenance activities, whether such asset balances include capitalized interest and the method by which such is calculated, how disposals of such assets are accounted for and how impairment of such assets is assessed and recognized. |
| Object type: | cm:Level2TextBlock |
| Data type: | Text Block (HTML) (nonnum:textBlockItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OilAndGasPropertiesPolicyPolicyTextBlock |
| Label | Role | Language |
| Oil and Gas Properties Policy [Policy Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 210 10 S99 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 235 10 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 235 |
| FASB Accounting Standards Codification 360 10 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 360 |