Uncertain tax positions.

No definition available.

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Namespace Prefix:	USEG_
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- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319

+ Details

Name:	us-gaap_OperatingLossCarryforwards
Namespace Prefix:	us-gaap_
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- Definition

A description of the limitations on the use of all operating loss carryforwards available to reduce future taxable income.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingLossCarryforwardsLimitationsOnUse
Namespace Prefix:	us-gaap_
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- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

+ Details

Name:	us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=USEG_FederalMember
Namespace Prefix:
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Balance Type:
Period Type:

Income Taxes (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details Narrative) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Description of limitation of use	The net operating losses may be used to offset future taxable income and expire in varying amounts through 2036.
Minimum tax credit carry-forwards	$ 785
Uncertain tax positions
Federal [Member]
Net operating loss carryovers	$ 3,600