TSR Share Based Compensation (Details)	9 Months Ended
Sep. 30, 2016
Long Term Incentive 2015 Plan [Member]
Total Shareholder Return Assumptions [Line Items]
Volatility of common stock	40.10%
Average volatility of peer companies	46.50%
Average correlation coefficient of peer companies	0.454
Risk-free interest rate	1.02%
Long Term Incentive 2014 Plan [Member]
Total Shareholder Return Assumptions [Line Items]
Volatility of common stock	39.00%
Risk-free interest rate	0.66%

A measure that determines the degree to which two variables movements are associated

No definition available.

Name:	upl_FairValueAssumptionsCorrelationCoefficient
Namespace Prefix:	upl_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

General descriptive information regarding an arrangement under which employees and directors receive: (a) awards of equity shares, equity share options, or other equity instruments; or (b) the entity incurs liabilities to them: (1) in amounts based, at least in part, on the price of the entity's shares or other equity instruments; or (2) that require or may require settlement by issuance of the entity's shares. Such an arrangement is usually provided to employees and directors to compensate them, provide performance incentives to them, and to attract or retain their services. May also include pertinent information particular to a plan that is not elsewhere specified in the taxonomy.

+ References

No definition available.

+ Details

Name:	upl_FairValueAssumptionsExpectedVolatilityRatePeers
Namespace Prefix:	upl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	upl_TotalShareholderReturnAssumptionsLineItems
Namespace Prefix:	upl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueAssumptionsExpectedVolatilityRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

+ Details

Name:	us-gaap_FairValueAssumptionsRiskFreeInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	upl_LongTermIncentivePlanAxis=upl_LongTermIncentive2015PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	upl_LongTermIncentivePlanAxis=upl_LongTermIncentive2014PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: