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Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Dec. 31, 2018	Dec. 31, 2017
Successor
Significant Accounting Policies [Line Items]
Enterprise value		$ 1,089,808,000
Capitalized costs	$ 38,062,000		$ 195,139,000	$ 294,345,000
Maximum reserves sold from cost center not expected to result in significant alteration (less than)			25.00%
Natural gas balancing liability			$ 1,700,000	1,600,000
Successor | Oil, natural gas and NGL revenues
Significant Accounting Policies [Line Items]
Transportation costs	7,400,000		27,700,000	29,100,000
Successor | Internal Costs
Significant Accounting Policies [Line Items]
Capitalized costs	4,000,000.0		$ 8,800,000	14,800,000
Successor | Oil And Gas Unproved Properties
Significant Accounting Policies [Line Items]
Interest capitalized during period	$ 0			$ 0
Predecessor
Significant Accounting Policies [Line Items]
Capitalized costs		156,954,000
Predecessor | Production expenses
Significant Accounting Policies [Line Items]
Transportation costs		26,200,000
Predecessor | Internal Costs
Significant Accounting Policies [Line Items]
Capitalized costs		22,700,000
Predecessor | Oil And Gas Unproved Properties
Significant Accounting Policies [Line Items]
Interest capitalized during period		2,200,000
Minimum | Successor | Buildings and structures
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			7 years
Minimum | Successor | Equipment
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			1 year
Minimum | Predecessor
Significant Accounting Policies [Line Items]
Estimated enterprise value		1,000,000,000.0
Maximum | Successor | Buildings and structures
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			39 years
Maximum | Successor | Equipment
Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			27 years
Maximum | Predecessor
Significant Accounting Policies [Line Items]
Estimated enterprise value		$ 1,300,000,000

X

- Definition

Amount of costs incurred related to oil and gas property acquisition, exploration and development activities, including capitalized costs and costs charged to expense.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

X

- Definition

The value of gas balancing asset or liability as of the end of the period.

+ References

No definition available.

+ Details

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X

- Definition

Amount of interest capitalized during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

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X

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

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X

- Definition

Includes the cost to prepare and move liquid hydrocarbons and natural gas to their points of sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 23
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62136-109447

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- Definition

Enterprise Value

+ References

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+ Details

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- Definition

Estimated Enterprise Value

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X

- Definition

The maximum percentage of reserves from a cost center that if sold would not ordinarily be expected to result in a significant alteration.

+ References

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- Definition

Significant Accounting Policies [Line Items]

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