| Standard label: | Exploration and Production Equipment [Member] |
| Name: | us-gaap:ExplorationAndProductionEquipmentMember |
| Documentation: | Equipment used in the process of surveying, preparing land for the extraction of natural resources and extracting natural resources. |
| Object type: | cm:Member |
| Data type: | [Member] (nonnum:domainItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:ExplorationAndProductionEquipmentMember |
| Label | Role | Language |
| Exploration and Production Equipment [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 932 235 50 5 (e) | http://fasb.org/us-gaap/role/ref/legacyRef | 932 |
| FASB Accounting Standards Codification 932 235 50 13 | http://fasb.org/us-gaap/role/ref/legacyRef | 932 |
| FASB Accounting Standards Codification 932 360 25 4 | http://fasb.org/us-gaap/role/ref/legacyRef | 932 |
| FASB Accounting Standards Codification 932 360 25 6 | http://fasb.org/us-gaap/role/ref/legacyRef | 932 |