| SourceName | Taxonomy Technical Improvement | http://fasb.org/srt/role/changeNote/changeNote |
| TaxonomyVersion | 2019 | http://fasb.org/srt/role/changeNote/changeNote |
| ChangeDate | 2018-10 | http://fasb.org/srt/role/changeNote/changeNote |
| ModifiedLabels | true | http://fasb.org/srt/role/changeNote/changeNote |
| ModifiedDocumentation | true | http://fasb.org/srt/role/changeNote/changeNote |
| PreviousDocumentation | Petroleum extracted from the ground and natural gas liquids (NGL). NGL are found with natural gas and usually are composed of ethane, propane, natural gasoline, butane, and isobutane. Excludes natural gas and liquefied natural gas. | http://fasb.org/srt/role/changeNote/changeNote |