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Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017
Statement of Cash Flows [Abstract] |  |  |  |  |
Non-cash (gain) loss on extinguishment of debt, net |  |  |  | $ 6,334 | $ 22
Loss on extinguishment of debt |  | $ 26,722 | $ 0 | 26,722 | 35
Net cash provided by operating activities |  |  |  | 541,177 | 370,610
Net cash provided by (used in) investing activities |  |  |  | (313,960) | 66,007
Cash paid for extinguishment of debt | [1] |  |  |  | 13
Net cash used in financing activities |  |  |  | (364,354) | (7,574)
Net change in cash, cash equivalents, and restricted cash |  |  |  |  | 429,043
Cash, cash equivalents, and restricted cash at beginning of period | [2] |  |  | 313,943 | 12,372
Cash, cash equivalents, and restricted cash at end of period | [2] | 176,806 | 441,415 | 176,806 | 441,415
Income Statement [Abstract] |  |  |  |  |
Exploration |  | 13,061 | 14,119 | 40,844 | 38,919
General and administrative |  | 29,464 | 27,564 | 86,066 | 84,618
Total operating expenses |  | 568,013 | 380,531 | 1,266,308 | 855,155
Income (loss) from operations |  | (108,644) | (85,152) | 406,572 | (66,317)
Other non-operating income, net |  | 806 | 861 | 3,017 | 1,581
Prior Period Adjustments Restatement [Line Items] |  |  |  |  |
Depletion, depreciation, amortization, and asset retirement obligation liability accretion |  | 201,105 | 134,599 | 483,343 | 425,643
Net income (loss) |  | 135,923 | 89,112 | (198,675) | 134,585
Previously Reported [Member] | Accounting Standards Update 2016-15, 2016-18 [Member] |  |  |  |  |
Statement of Cash Flows [Abstract] |  |  |  |  |
Non-cash (gain) loss on extinguishment of debt, net |  |  |  |  | 22
Net cash provided by operating activities |  |  |  |  | 370,597
Acquisition deposit held in escrow |  |  |  |  | 3,000
Net cash provided by (used in) investing activities |  |  |  |  | 69,007
Net cash used in financing activities |  |  |  |  | (7,561)
Net change in cash and cash equivalents |  |  |  |  | 432,043
Cash and cash equivalents at beginning of period |  |  |  |  | 9,372
Cash and cash equivalents at end of period |  |  | 441,415 |  | 441,415
Previously Reported [Member] | Accounting Standards Update 2017-07 [Member] |  |  |  |  |
Income Statement [Abstract] |  |  |  |  |
Exploration |  |  | 14,243 |  | 39,293
General and administrative |  |  | 27,880 |  | 85,564
Total operating expenses |  |  | 380,971 |  | 856,475
Income (loss) from operations |  |  | (85,592) |  | (67,637)
Other non-operating income, net |  |  | $ 1,301 |  | $ 2,901
Correction of Immaterial Errors Before Tax [Member] |  |  |  |  |
Prior Period Adjustments Restatement [Line Items] |  |  |  |  |
Depletion, depreciation, amortization, and asset retirement obligation liability accretion |  | 11,800 |  | 11,800 |
Understatement of Net Income After Tax [Member] |  |  |  |  |
Prior Period Adjustments Restatement [Line Items] |  |  |  |  |
Net income (loss) |  |  |  | $ 9,000 |
Overstatement of Net Loss After Tax [Member] |  |  |  |  |
Prior Period Adjustments Restatement [Line Items] |  |  |  |  |
Net income (loss) |  | $ 9,000 |  |  |
[1] | (1) Included as a component within the cash paid to repurchase Senior Notes, including premium line item on the accompanying statements of cash flows.
[2] | (1) Refer to Note 1 - Summary of Significant Accounting Policies for a reconciliation of cash, cash equivalents, and restricted cash reported to the amounts reported within the accompanying unaudited condensed consolidated balance sheets (“accompanying balance sheets”).

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- Definition Amount of cash and cash equivalents; including, but not limited to, disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
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- Definition Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; including, but not limited to, disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3521-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3044-108585 + Details
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- Definition Exploration expenses (including prospecting) related to oil and gas producing entities and would be included in operating expenses of that entity. Costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of containing oil and gas reserves, including costs of drilling exploratory wells and exploratory-type stratigraphic test wells. Exploration costs may be incurred both before acquiring the related property (sometimes referred to in part as prospecting costs) and after acquiring the property. Principal types of exploration costs, which include depreciation and applicable operating costs of support equipment and facilities and other costs of exploration activities, are: (i) Costs of topographical, geographical and geophysical studies, rights of access to properties to conduct those studies, and salaries and other expenses of geologists, geophysical crews, and others conducting those studies. Collectively, these are sometimes referred to as geological and geophysical or "G&G" costs. (ii) Costs of carrying and retaining undeveloped properties, such as delay rentals, ad valorem taxes on properties, legal costs for title defense, and the maintenance of land and lease records. (iii) Dry hole contributions and bottom hole contributions. (iv) Costs of drilling and equipping exploratory wells. (v) Costs of drilling exploratory-type stratigraphic test wells. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 23 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62136-109447 + Details
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