Debt instrument, repurchase price percentage.

No definition available.

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

- Definition

Redemption criteria.

+ References

No definition available.

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Percentage of principal amount of debt redeemed.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=upl_SixPointEightSevenFivePercentageSeniorUnsecuredNotesDueTwentyTwentyTwoMember
Namespace Prefix:
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- Details

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Data Type:	na
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- Details

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Data Type:	na
Balance Type:
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- Details

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- Details

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- Details

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- Details

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- Details

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Debt and Other Long Term Obligations - Ultra Resources, Inc. - Senior Notes - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Apr. 12, 2017
6.875% Senior, Unsecured Notes Due 2022
Debt Instrument [Line Items]
Stated interest rate	6.875%
Maturity date	Apr. 15, 2022
7.125% Senior, Unsecured Notes Due 2025
Debt Instrument [Line Items]
Stated interest rate	7.125%
Maturity date	Apr. 15, 2025
Ultra Resources, Inc.
Debt Instrument [Line Items]
Interest payment terms	The 2022 Notes will mature on April 15, 2022. The interest payment dates for the 2022 Notes are April 15 and October 15 of each year, commencing on October 15, 2017. The 2025 Notes will mature on April 15, 2025. The interest payment dates for the 2025 Notes are April 15 and October 15 of each year, commencing on October 15, 2017. Interest will be paid on the Notes from the issue date until maturity.
Repurchase price percentage	101.00%
Ultra Resources, Inc. \| 6.875% Senior, Unsecured Notes Due 2022
Debt Instrument [Line Items]
Debt instrument, face amount		$ 700,000,000
Stated interest rate		6.875%
Maturity date	Apr. 15, 2022
Redemption price percentage of principal amount	106.875%
Redemption criteria	If at least 65% of the original principal amount of the 2022 Notes remains outstanding and the redemption occurs within 180 days of the closing of such equity offering.
Ultra Resources, Inc. \| 6.875% Senior, Unsecured Notes Due 2022 \| Maximum
Debt Instrument [Line Items]
Redemption price percentage of aggregate principal amount	35.00%
Ultra Resources, Inc. \| 6.875% Senior, Unsecured Notes Due 2022 \| Twelve-Month Period Beginning on April 15, 2019
Debt Instrument [Line Items]
Redemption price percentage of principal amount	103.438%
Ultra Resources, Inc. \| 6.875% Senior, Unsecured Notes Due 2022 \| Twelve-Month Period Beginning April 15, 2020
Debt Instrument [Line Items]
Redemption price percentage of principal amount	101.719%
Ultra Resources, Inc. \| 6.875% Senior, Unsecured Notes Due 2022 \| Twelve-Month Period Beginning April 15, 2021
Debt Instrument [Line Items]
Redemption price percentage of principal amount	100.00%
Ultra Resources, Inc. \| 7.125% Senior, Unsecured Notes Due 2025
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500,000,000
Stated interest rate		7.125%
Maturity date	Apr. 15, 2025
Redemption price percentage of principal amount	107.125%
Redemption criteria	If at least 65% of the original principal amount of the 2025 Notes remains outstanding and the redemption occurs within 180 days of the closing of such equity offering.
Ultra Resources, Inc. \| 7.125% Senior, Unsecured Notes Due 2025 \| Maximum
Debt Instrument [Line Items]
Redemption price percentage of aggregate principal amount	35.00%
Ultra Resources, Inc. \| 7.125% Senior, Unsecured Notes Due 2025 \| Twelve-Month Period Beginning April 15, 2020
Debt Instrument [Line Items]
Redemption price percentage of principal amount	105.344%
Ultra Resources, Inc. \| 7.125% Senior, Unsecured Notes Due 2025 \| Twelve-Month Period Beginning April 15, 2021
Debt Instrument [Line Items]
Redemption price percentage of principal amount	103.563%
Ultra Resources, Inc. \| 7.125% Senior, Unsecured Notes Due 2025 \| Twelve-Month Period Beginning April 15, 2022
Debt Instrument [Line Items]
Redemption price percentage of principal amount	101.781%
Ultra Resources, Inc. \| 7.125% Senior, Unsecured Notes Due 2025 \| Twelve-Month Period Beginning April 15, 2023
Debt Instrument [Line Items]
Redemption price percentage of principal amount	100.00%