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Summary of Significant Accounting Policies Other (Details) |  | 12 Months Ended |
--- | --- | --- | ---
Dec. 31, 2018 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 | Feb. 21, 2019
Concentration of Credit Risk and Major Customers [Abstract] |  |  |  |  |  |  |  |  |
Entity-Wide Revenue, Major Customer, Percentage |  |  | 100.00% | [1] | 100.00% | [2] | 100.00% | [3] |
Number of individual entities within groups of entities under common ownership that represent more than 10 percent of total production revenue |  |  | 0 |  |  |  |  |  |
Revolving Credit Facility [Member] | Line of Credit [Member] |  |  |  |  |  |  |  |  |
Basis of Presentation and Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Long-term Line of Credit |  | $ 0 | $ 0 |  | $ 0 |  |  |  |
Minimum [Member] |  |  |  |  |  |  |  |  |
Revenues [Abstract] |  |  |  |  |  |  |  |  |
Revenue Receipt, Days After Sale |  |  | 30 |  |  |  |  |  |
Maximum [Member] |  |  |  |  |  |  |  |  |
Revenues [Abstract] |  |  |  |  |  |  |  |  |
Revenue Receipt, Days After Sale |  |  | 90 |  |  |  |  |  |
Oil and Gas Properties [Member] |  |  |  |  |  |  |  |  |
Impairment of Proved, Unproved, and Other Properties [Abstract] |  |  |  |  |  |  |  |  |
Period of New York Mercantile Exchange Strip Pricing Used for Price Forecast |  | 5 years |  |  |  |  |  |  |
Property, Plant and Equipment, Other Types [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |
Property, Plant and Equipment [Abstract] |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Estimated Useful Lives |  |  | 3 years |  |  |  |  |  |
Property, Plant and Equipment, Other Types [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |
Property, Plant and Equipment [Abstract] |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Estimated Useful Lives |  |  | 30 years |  |  |  |  |  |
Customer Concentration Risk [Member] | Oil, gas, and NGLS revenue [Member] | Major Customer One [Member] |  |  |  |  |  |  |  |  |
Concentration of Credit Risk and Major Customers [Abstract] |  |  |  |  |  |  |  |  |
Entity-Wide Revenue, Major Customer, Percentage | [4] |  | 18.00% |  | 6.00% |  | 0.00% |  |
Customer Concentration Risk [Member] | Oil, gas, and NGLS revenue [Member] | Major Customer Two [Member] |  |  |  |  |  |  |  |  |
Concentration of Credit Risk and Major Customers [Abstract] |  |  |  |  |  |  |  |  |
Entity-Wide Revenue, Major Customer, Percentage | [4] |  | 10.00% |  | 10.00% |  | 5.00% |  |
Customer Concentration Risk [Member] | Oil, gas, and NGLS revenue [Member] | Unnamed Major Customer One with Related Entities [Member] |  |  |  |  |  |  |  |  |
Concentration of Credit Risk and Major Customers [Abstract] |  |  |  |  |  |  |  |  |
Entity-Wide Revenue, Major Customer, Percentage | [5] |  | 18.00% |  | 17.00% |  | 15.00% |  |
Customer Concentration Risk [Member] | Oil, gas, and NGLS revenue [Member] | Unnamed Major Customer Two with Related Entities [Member] |  |  |  |  |  |  |  |  |
Concentration of Credit Risk and Major Customers [Abstract] |  |  |  |  |  |  |  |  |
Entity-Wide Revenue, Major Customer, Percentage | [5] |  | 12.00% |  | 8.00% |  | 8.00% |  |
Measurement Input, Discount Rate [Member] | Oil and Gas Properties [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |
Basis of Presentation and Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Fair Value Assumptions, Measurement Input |  | 0.10 | 0.10 |  |  |  |  |  |
Measurement Input, Discount Rate [Member] | Oil and Gas Properties [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |
Basis of Presentation and Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Fair Value Assumptions, Measurement Input |  | 0.15 | 0.15 |  |  |  |  |  |
Measurement Input, Risk Free Interest Rate [Member] | Asset Retirement Obligation Costs [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |
Basis of Presentation and Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Fair Value Assumptions, Measurement Input |  | 0.055 | 0.055 |  |  |  |  |  |
Measurement Input, Risk Free Interest Rate [Member] | Asset Retirement Obligation Costs [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |
Basis of Presentation and Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Fair Value Assumptions, Measurement Input |  | 0.12 | 0.12 |  |  |  |  |  |
Subsequent Event [Member] |  |  |  |  |  |  |  |  |
Concentration of Credit Risk and Major Customers [Abstract] |  |  |  |  |  |  |  |  |
Number of Derivative Counterparties |  |  |  |  |  |  |  |  | 10
[1] | Note: Amounts may not calculate due to rounding.
[2] | Note: Amounts may not calculate due to rounding.
[3] | Note: Amounts may not calculate due to rounding.
[4] | (1) These major customers are purchasers of a portion of the Company’s production from its Permian region.
[5] | (2) In the aggregate, these groups of entities under common ownership represented more than 10 percent of total oil, gas, and NGL production revenue for at least one of the periods presented; however, no individual entity comprising either group represented more than 10 percent of the Company’s total oil, gas, and NGL production revenue.

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