Share Based Compensation (Narratives) (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015
Share Based Compensation Details [Abstract]
Long Term Incentive Program Period	$ 3.3	$ 4.7
Long Term Incentive Program Total 2014 Program	9.3
Long Term Incentive Program Total 2015 Program	10.1
Long Term Incentive Program Total 2013 Program	$ 3.8
Long Term Incentive Program Total 2013 Program Shares	132,843

Pretax compensation expense recognized related to the Long Term Incentive Program in the period.

No definition available.

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Balance Type:	debit
Period Type:	duration

The actual compensation paid in shares of the company's common stock for each of the three year performance periods related to the 2013 LTIP.

No definition available.

Name:	upl_LongTermIncentiveProgramTotal2013Program
Namespace Prefix:	upl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Net shares awarded and issued associated with the 2013 Long Term Incentive Program.

No definition available.

Name:	upl_LongTermIncentiveProgramTotal2013ProgramShares
Namespace Prefix:	upl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The estimated total compensation for each of the three year performance periods related to the 2014 LTIP.

No definition available.

Name:	upl_LongTermIncentiveProgramTotal2014Program
Namespace Prefix:	upl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The estimated total compensation for each of the three year performance periods related to the 2015 LTIP.

No definition available.

Name:	upl_LongTermIncentiveProgramTotal2015Program
Namespace Prefix:	upl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

No definition available.

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Namespace Prefix:	upl_
Data Type:	xbrli:stringItemType
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