Identification of the name or type of counterparty to the derivative instrument.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column A

-Footnote 1

+ Details

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- Definition

The quantity per day of future oil and gas production being hedged.

+ References

No definition available.

+ Details

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Namespace Prefix:	useg_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 205G

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44C

-Subparagraph a

-Clause 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (a),(c)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Fair value of derivative liability, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

+ References

+ Details

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Balance Type:	credit
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- Definition

Net Increase or Decrease in the fair value of the derivative or group of derivatives included in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The strike price on the price risk option contract such as a put option or a call option.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Reference to the index or unit of measurement for the underlying which establishes the pricing terms of the derivative instrument. For example, the basis on the underlying for a natural gas futures contract might be the NYMEX price per million British thermal units (MMBtu).

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Gain (loss) incurred in risk management activities.

+ References

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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COMMODITY PRICE RISK MANAGEMENT (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Realized derivative gain (loss)	$ (338)	$ 21	$ (1,974)
Unrealized derivative gain (loss)	(737)	1,070	1,126
Total realized and unrealized derivative gain (loss)	(1,075)	1,091	(848)
Current Asset [Member] \| Crude Oil Costless Collars [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	14	472
Current Liability [Member] \| Crude Oil Costless Collars [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	$ 280	$ 0
Crude Oil Costless Collar 01/01/14 - 06/30/14 [Member]
Derivative [Line Items]
Counterparty	Wells Fargo
Basis	WTI
Quantity (barrels per day)	300
Crude Oil Costless Collar 01/01/14 - 06/30/14 [Member] \| Put Option [Member]
Derivative [Line Items]
Strike Price (in dollars per barrel)	90.00
Crude Oil Costless Collar 01/01/14 - 06/30/14 [Member] \| Call Option [Member]
Derivative [Line Items]
Strike Price (in dollars per barrel)	95.00
Crude Oil Costless Collar 01/01/14 - 06/30/14 (2) [Member]
Derivative [Line Items]
Counterparty	Wells Fargo
Basis	WTI
Quantity (barrels per day)	300
Crude Oil Costless Collar 01/01/14 - 06/30/14 (2) [Member] \| Put Option [Member]
Derivative [Line Items]
Strike Price (in dollars per barrel)	90.00
Crude Oil Costless Collar 01/01/14 - 06/30/14 (2) [Member] \| Call Option [Member]
Derivative [Line Items]
Strike Price (in dollars per barrel)	97.25
Crude Oil Costless Collar 07/01/14 - 12/31/14 [Member]
Derivative [Line Items]
Counterparty	Wells Fargo
Basis	WTI
Quantity (barrels per day)	300
Crude Oil Costless Collar 07/01/14 - 12/31/14 [Member] \| Put Option [Member]
Derivative [Line Items]
Strike Price (in dollars per barrel)	90.00
Crude Oil Costless Collar 07/01/14 - 12/31/14 [Member] \| Call Option [Member]
Derivative [Line Items]
Strike Price (in dollars per barrel)	98.40