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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)		160us-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)	800.77us-gaap_GasAndOilAreaDevelopedGross / dei_LegalEntityAxis = useg_DimmitWoodPropertiesLtdMember
Working interest percentage (in hundredths)	30.00%useg_WorkingInterest / dei_LegalEntityAxis = useg_DimmitWoodPropertiesLtdMember

X

- Definition

The minimum period of entry of the Decree from the final determination of the pending patent application.

+ References

No definition available.

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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.

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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

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