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Commitments and Contingencies (Details) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2015 | Jan. 21, 2014 acre
Water Rights Litigation Mt. Emmons Project [Abstract] |  |
Period for proposal submission | 6 years |
Gas and Oil Acreage [Line Items] |  |
Gross acres acquired in acquisition (in acres) |  | 160 us-gaap_GasAndOilAreaDevelopedGross
Working interest percentage (in hundredths) |  | 50.00%useg_WorkingInterest
Dimmit Wood Properties Ltd [Member] |  |
Gas and Oil Acreage [Line Items] |  |
Gross acres acquired in acquisition (in acres) | 800.77 us-gaap_GasAndOilAreaDevelopedGross / dei_LegalEntityAxis = useg_DimmitWoodPropertiesLtdMember |
Working interest percentage (in hundredths) | 30.00%useg_WorkingInterest / dei_LegalEntityAxis = useg_DimmitWoodPropertiesLtdMember |

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- Definition The minimum period of entry of the Decree from the final determination of the pending patent application. + References No definition available. + Details
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- Definition A percentage of ownership in an oil and gas lease granting its owner the right to explore, drill and produce oil and gas from a tract of property. Working interest owners are obligated to pay a corresponding percentage of the cost of leasing, drilling, producing and operating a well or unit. After royalties are paid, the working interest also entitles its owner to share in production revenues with other working interest owners, based on the percentage of working interest owned. + References No definition available. + Details
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- Definition Area spaced or assigned to productive wells in which a working interest is owned. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Industry Guide -Number 2 -Paragraph 4 -Subparagraph A + Details
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