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Represents the assumption of capital commitments in a joint venture.

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Represents information about that the entity owns number of miles of high pressure natural gas gathering pipelines.

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Per day energy measure of interests in proved developed reserves of crude oil, including condensate and natural gas liquids, natural gas, synthetic oil and gas, or other nonrenewable natural resource that is intended to be upgraded into synthetic oil and gas.

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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.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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The cash inflow associated with the acquisition of business during the period (for example, cash that was held by the acquired business).

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Amount of gain (loss) on sale or disposal of intangible assets.

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Amount of gain (loss) on sale or disposal of proven and unproven oil and gas properties.

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Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

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The cash inflow associated with the amount received from the sale of a business segment or subsidiary or sale of an entity that is related to it but not strictly controlled during the period (for example, an unconsolidated subsidiary, affiliate, joint venture or equity method investment).

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The total number of producing oil wells and oil wells capable of production, in which the entity owns a fractional working interest.

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Acquisitions and Divestitures (Details)		1 Months Ended					3 Months Ended		13 Months Ended	18 Months Ended
Acquisitions and Divestitures (Details)	Jul. 05, 2016 USD ($)	Oct. 31, 2017 USD ($)	May 31, 2017 USD ($)	Nov. 30, 2016 USD ($) MMcfe / d item	Jul. 31, 2016 USD ($) mi	Jun. 30, 2016 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Carnero Processing, Joint Venture
Business Acquisition [Line Items]
Capital contribution commitments									$ 18,800,000
Ownership interest (as a percent)				50.00%
Payments to acquire interest in joint venture				$ 55,500,000
Assumption of capital commitments in joint venture				$ 24,500,000
Proved developed reserves (in mmcf/d) \| MMcfe / d				260
Targa
Business Acquisition [Line Items]
Ownership interest (as a percent)				50.00%	50.00%
Carnero Gathering, Joint Venture
Business Acquisition [Line Items]
Ownership interest (as a percent)	50.00%				50.00%
Payments to acquire interest in joint venture	$ 37,000,000				$ 37,000,000					$ 8,800,000
Assumption of capital commitments in joint venture	$ 7,400,000				$ 7,400,000
Number of miles of high pressure natural gas gathering pipelines \| mi					45
Agreement Term					15 years
SN Cotulla Assets, LLC and SN Palmetto, LLC
Business Acquisition [Line Items]
Producing wellbores \| item				23
SN Cotulla Assets, LLC and SN Palmetto, LLC \| Eagle Ford
Business Acquisition [Line Items]
Cash payment for acquisition				$ 24,200,000
Producing wellbores \| item				11
Closing adjustments				$ 2,800,000
Texas Production Divestiture
Business Acquisition [Line Items]
Proceeds from divestiture of business		$ 6,300,000
Gain on sale							$ 1,400,000
Oklahoma Production Divestiture
Business Acquisition [Line Items]
Proceeds from divestiture of business			$ 5,500,000
Gain on sale								$ 2,400,000
Mid-Continent Divestiture
Business Acquisition [Line Items]
Proceeds from divestiture of business						$ 7,120
Loss on disposition of intangible assets						$ 200,000
Sanchez Energy
Business Acquisition [Line Items]
Payments to acquire interest in joint venture				25,000,000
Assumption of capital commitments in joint venture				$ 24,200,000
Gathering Agreement delivery commitment period					5 years