Chord Energy (CHRD) 10-Q 3 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 31, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	OAS
Entity Registrant Name	Oasis Petroleum Inc.
Entity Central Index Key	1,486,159
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		237,415,441

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 11,440	$ 11,226
Accounts receivable, net	218,302	204,335
Inventory	17,942	10,648
Prepaid expenses	10,610	7,623
Derivative instruments	31,851	362
Other current assets	62	4,355
Total current assets	290,207	238,549
Property, plant and equipment
Oil and gas properties (successful efforts method)	7,488,075	7,296,568
Other property and equipment	695,592	618,790
Less: accumulated depreciation, depletion, amortization and impairment	(2,252,653)	(1,995,791)
Total property, plant and equipment, net	5,931,014	5,919,567
Derivative instruments	11,834	0
Long-term inventory	8,762	0
Other assets	19,904	20,516
Total assets	6,261,721	6,178,632
Current liabilities
Accounts payable	12,257	4,645
Revenues and production taxes payable	143,715	139,737
Accrued liabilities	139,766	119,173
Accrued interest payable	39,128	39,004
Derivative instruments	0	60,469
Advances from joint interest partners	5,816	7,597
Other current liabilities	0	10,490
Total current liabilities	340,682	381,115
Long-term debt	2,359,683	2,297,214
Deferred income taxes	527,181	513,529
Asset retirement obligations	51,059	48,985
Derivative instruments	0	11,714
Other liabilities	5,506	2,918
Total liabilities	3,284,111	3,255,475
Commitments and contingencies
Stockholders’ equity
Common stock, $0.01 par value: 450,000,000 shares authorized; 238,642,598 shares issued and 237,410,395 shares outstanding at June 30, 2017 and 237,201,064 shares issued and 236,344,172 shares outstanding at December 31, 2016	2,345	2,331
Treasury stock, at cost: 1,232,203 and 856,892 shares at June 30, 2017 and December 31, 2016, respectively	(21,401)	(15,950)
Additional paid-in capital	2,362,084	2,345,271
Retained earnings	634,582	591,505
Total stockholders’ equity	2,977,610	2,923,157
Total liabilities and stockholders’ equity	$ 6,261,721	$ 6,178,632

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	450,000,000	450,000,000
Common stock, shares issued (in shares)	238,642,598	237,201,064
Common stock, shares outstanding (in shares)	237,410,395	236,344,172
Treasury stock, shares (in shares)	1,232,203	856,892

Condensed Consolidated Statemen

Condensed Consolidated Statement of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues
Oil and gas revenues	$ 218,633	$ 159,337	$ 455,885	$ 276,652
Bulk oil sales	8,091	0	35,722	0
Midstream revenues	15,566	6,910	30,172	13,893
Well services revenues	11,801	12,833	17,428	18,818
Total revenues	254,091	179,080	539,207	309,363
Operating expenses
Lease operating expenses	44,665	31,523	88,537	62,587
Midstream operating expenses	3,263	1,740	6,590	3,478
Well services operating expenses	8,088	7,135	11,990	9,786
Marketing, transportation and gathering expenses	12,039	6,491	22,990	15,043
Bulk oil purchases	7,980	0	35,982	0
Production taxes	18,971	14,367	39,270	25,120
Depreciation, depletion and amortization	125,291	122,488	251,957	244,937
Exploration expenses	1,667	340	3,156	703
Impairment	3,200	23	5,882	3,585
General and administrative expenses	23,548	21,876	47,382	46,242
Total operating expenses	248,712	205,983	513,736	411,481
Loss on sale of properties	0	(1,311)	0	(1,311)
Operating income (loss)	5,379	(28,214)	25,471	(103,429)
Other income (expense)
Net gain (loss) on derivative instruments	50,532	(90,846)	106,607	(76,471)
Interest expense, net of capitalized interest	(36,838)	(34,979)	(73,159)	(73,718)
Gain on extinguishment of debt	0	11,642	0	18,658
Other income (expense)	(166)	(32)	(150)	447
Total other income (expense)	13,528	(114,215)	33,298	(131,084)
Income (loss) before income taxes	18,907	(142,429)	58,769	(234,513)
Income tax benefit (expense)	(2,339)	52,498	(18,376)	80,127
Net income (loss)	$ 16,568	$ (89,931)	$ 40,393	$ (154,386)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.07	$ (0.51)	$ 0.17	$ (0.91)
Diluted (in dollars per share)	$ 0.07	$ (0.51)	$ 0.17	$ (0.91)
Weighted average shares outstanding:
Basic (in shares)	233,283	176,984	233,176	169,953
Diluted (in shares)	234,917	176,984	236,281	169,953

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in-Capital [Member]	Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment for adoption of ASU 2016-09	$ 4,724			$ 2,040	$ 2,684
Balance (shares) at Dec. 31, 2016		236,344	857
Balance at Dec. 31, 2016	2,923,157	$ 2,331	$ (15,950)	2,345,271	591,505
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Fees (2016 issuance of common stock) (shares)		0
Fees (2016 issuance of common stock)	(55)	$ 0		(55)
Stock-based compensation (shares)		1,441
Stock-based compensation	14,842	$ 14		14,828
Treasury stock - tax withholdings (shares)		(375)	375
Treasury stock - tax withholdings	(5,451)		$ (5,451)
Net income	40,393				40,393
Balance (shares) at Jun. 30, 2017		237,410	1,232
Balance at Jun. 30, 2017	$ 2,977,610	$ 2,345	$ (21,401)	$ 2,362,084	$ 634,582

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ 40,393	$ (154,386)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	251,957	244,937
Gain on extinguishment of debt	0	(18,658)
Loss on sale of properties	0	1,311
Impairment	5,882	3,585
Deferred income taxes	18,376	(80,127)
Derivative instruments	(106,607)	76,471
Stock-based compensation expenses	13,823	12,979
Deferred financing costs amortization and other	8,871	6,552
Working capital and other changes:
Change in accounts receivable	(13,743)	4,297
Change in inventory	(1,007)	2,054
Change in prepaid expenses	(264)	1,423
Change in other current assets	280	(114)
Change in long-term inventory and other assets	(8,768)	100
Change in accounts payable, interest payable and accrued liabilities	11,158	(18,034)
Change in other current liabilities	(10,490)	9,001
Change in other liabilities	0	10
Net cash provided by operating activities	209,861	91,401
Cash flows from investing activities:
Capital expenditures	(252,461)	(231,341)
Proceeds from sale of properties	4,000	11,679
Costs related to sale of properties	0	(310)
Derivative settlements	(8,899)	103,790
Advances from joint interest partners	(1,781)	769
Net cash used in investing activities	(259,141)	(115,413)
Cash flows from financing activities:
Proceeds from revolving credit facility	484,000	359,000
Principal payments on revolving credit facility	(429,000)	(462,000)
Repurchase of senior unsecured notes	0	(56,925)
Deferred financing costs	0	(751)
Proceeds from sale of common stock	0	182,953
Purchases of treasury stock	(5,451)	(1,520)
Other	(55)	0
Net cash provided by financing activities	49,494	20,757
Increase (decrease) in cash and cash equivalents	214	(3,255)
Cash and cash equivalents:
Beginning of period	11,226	9,730
End of period	11,440	6,475
Supplemental non-cash transactions:
Change in accrued capital expenditures	19,017	(17,015)
Change in asset retirement obligations	1,759	(8,785)
Notes payable from acquisition	$ 4,875	$ 0

Organization and Operations of

Organization and Operations of the Company	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Organization and Operations of the Company	Organization and Operations of the Company Oasis Petroleum Inc. (together with its consolidated subsidiaries, “Oasis” or the “Company”) was originally formed in 2007 and was incorporated pursuant to the laws of the State of Delaware in 2010. The Company is an independent exploration and production company focused on the acquisition and development of unconventional oil and natural gas resources in the North Dakota and Montana regions of the Williston Basin. Oasis Petroleum North America LLC (“OPNA”) conducts the Company’s exploration and production activities and owns its proved and unproved oil and natural gas properties. The Company also operates a midstream services business through Oasis Midstream Services LLC (“OMS”) and a well services business through Oasis Well Services LLC (“OWS”), both of which are separate reportable business segments that are complementary to its primary development and production activities.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements of the Company include the accounts of Oasis and its wholly-owned subsidiaries. All significant intercompany transactions have been eliminated in consolidation. The accompanying condensed consolidated financial statements of the Company have not been audited by the Company’s independent registered public accounting firm, except that the Condensed Consolidated Balance Sheet at December 31, 2016 is derived from audited financial statements. Certain reclassifications of prior year balances have been made to conform such amounts to current year classifications. These reclassifications have no impact on net income. In the opinion of management, all adjustments, consisting of normal recurring adjustments necessary for the fair statement, have been included. Management has made certain estimates and assumptions that affect reported amounts in the condensed consolidated financial statements and disclosures of contingencies. Actual results may differ from those estimates. The results for interim periods are not necessarily indicative of annual results. These interim financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain disclosures have been condensed or omitted from these financial statements. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete consolidated financial statements and should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (“ 2016 Annual Report”). Risks and Uncertainties As an oil and natural gas producer, the Company’s revenue, profitability and future growth are substantially dependent upon the prevailing and future prices for oil and natural gas, which are dependent upon numerous factors beyond its control such as economic, political and regulatory developments and competition from other energy sources. The energy markets have historically been very volatile, and there can be no assurance that oil and natural gas prices will not be subject to wide fluctuations in the future. An extended period of low prices for oil and, to a lesser extent, natural gas could have a material adverse effect on the Company’s financial position, results of operations, cash flows and quantities of oil and natural gas reserves that may be economically produced. Significant Accounting Policies There have been no material changes to the Company’s critical accounting policies and estimates from those disclosed in the 2016 Annual Report, other than as noted below. Stock-based compensation. In the first quarter of 2017, the Company adopted Accounting Standards Update No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”), which updates several aspects of the accounting for share-based payment transactions, including recognition of excess tax benefits and deficiencies, the classification of those excess tax benefits on the statement of cash flows, an accounting policy election for forfeitures, the amount an employer can withhold to cover income taxes and still qualify for equity classification and the classification of those taxes paid on the statement of cash flows. In accordance with the new guidance, the Company recorded a $2.7 million cumulative-effect adjustment to retained earnings on the Company’s Condensed Consolidated Balance Sheet as of June 30, 2017 , which included recognition of excess tax benefits and deficiencies and the removal of the estimated forfeiture rate. ASU 2016-09 was applied on a modified retrospective basis and prior periods were not retrospectively adjusted. Inventory. In the first quarter of 2017, the Company adopted Accounting Standards Update No. 2015-11, Simplifying the Measurement of Inventory (“ASU 2015-11”), which changes the inventory measurement principle from lower of cost or market to lower of cost and net realizable value for entities using the first-in, first-out or average cost methods. ASU 2015-11 was applied on a prospective basis and prior periods were not retrospectively adjusted. There was no material impact as a result of adoption as of June 30, 2017 . Recent Accounting Pronouncements Revenue recognition. In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). The objective of ASU 2014-09 is greater consistency and comparability across industries by using a five-step model to recognize revenue from customer contracts. ASU 2014-09 also contains some new disclosure requirements under GAAP. In August 2015, the FASB issued Accounting Standards Update No. 2015-14, Deferral of the Effective Date (“ASU 2015-14”). ASU 2015-14 defers the effective date of the new revenue standard by one year, making it effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. In 2016, the FASB issued additional accounting standards updates to clarify the implementation guidance of ASU 2014-09. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Financial instruments. In January 2016, the FASB issued Accounting Standards Update No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which requires that most equity instruments be measured at fair value with subsequent changes in fair value recognized in net income. ASU 2016-01 also impacts financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. ASU 2016-01 does not apply to equity method investments or investments in consolidated subsidiaries. ASU 2016-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those years. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Leases. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (“ASU 2016-02”), which requires a lessee to recognize lease payment obligations and a corresponding right-of-use asset to be measured at fair value on the balance sheet. ASU 2016-02 also requires certain qualitative and quantitative disclosures about the amount, timing and uncertainty of cash flows arising from leases. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those years. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Statement of cash flows. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (“ASU 2016-15”), which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, including interim periods within those years. The adoption of this guidance will not impact the Company’s financial position or results of operations, but could result in presentation changes on the Company’s statement of cash flows. Business combinations. In January 2017, the FASB issued Accounting Standards Update No. 2017-01, Clarifying the Definition of a Business (“ASU 2017-01”), which provides guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU 2017-01 requires entities to use a screen test to determine when an integrated set of assets and activities is not a business or if the integrated set of assets and activities needs to be further evaluated against the framework. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those years. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Stock-based compensation. In May 2017, the FASB issued Accounting Standards Update No. 2017-09, Scope of Modification Accounting (“ASU 2017-09”), which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The adoption of ASU 2017-09 will become effective for annual periods beginning after December 15, 2017, and the Company is currently evaluating the impact that it will have on its financial position, cash flows and results of operations.

Inventory

Inventory	6 Months Ended
	Jun. 30, 2017
Inventory Disclosure [Abstract]
Inventory	Inventory Crude oil inventory includes oil in tank. Equipment and materials consist primarily of proppant, chemicals, tubular goods, well equipment to be used in future drilling or repair operations and well fracturing equipment. Crude oil inventory and equipment and materials are included in Inventory on the Company’s Condensed Consolidated Balance Sheets. The minimum volume of product in a pipeline system that enables the system to operate is known as linefill and is generally not available to be withdrawn from the pipeline system until the expiration of the transportation contract. The Company owns oil linefill in third-party pipelines, which is included in Long-term inventory on the Company’s Condensed Consolidated Balance Sheets. Inventory , including long-term inventory, is stated at the lower of cost and net realizable value with cost determined on an average cost method. T he Company assesses the carrying value of inventory and uses estimates and judgment when making any adjustments necessary to reduce the carrying value to net realizable value. Among the uncertainties that impact the Company’s estimates are the applicable quality and location differentials to include in the Company’s net realizable value analysis. Additionally, the Company estimates the upcoming liquidation timing of the inventory. Changes in assumptions made as to the timing of a sale can materially impact net realizable value. Total inventory consists of the following: June 30, 2017 December 31, 2016 (In thousands) Inventory Crude oil inventory $ 7,846 $ 7,086 Equipment and materials 10,096 3,562 Total inventory $ 17,942 $ 10,648 Long-term inventory Linefill in third-party pipelines $ 8,762 $ — Long-term inventory $ 8,762 $ — Total $ 26,704 $ 10,648

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements In accordance with the FASB’s authoritative guidance on fair value measurements, the Company’s financial assets and liabilities are measured at fair value on a recurring basis. The Company’s financial instruments, including certain cash and cash equivalents, accounts receivable, accounts payable and other payables, are carried at cost, which approximates their respective fair market values due to their short-term maturities. The Company recognizes its non-financial assets and liabilities, such as asset retirement obligations (“ARO”) and proved oil and natural gas properties upon impairment, at fair value on a non-recurring basis. As defined in the authoritative guidance, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). To estimate fair value, the Company utilizes market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable. The authoritative guidance establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (“Level 1” measurements) and the lowest priority to unobservable inputs (“Level 3” measurements). The three levels of the fair value hierarchy are as follows: Level 1 — Unadjusted quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 — Pricing inputs, other than unadjusted quoted prices in active markets included in Level 1, are either directly or indirectly observable as of the reporting date. Level 2 includes those financial instruments that are valued using models or other valuation methodologies. These models are primarily industry-standard models that consider various assumptions, including quoted forward prices for commodities, time value, volatility factors and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace throughout the full term of the instrument and can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace. Level 3 — Pricing inputs are generally less observable from objective sources, requiring internally developed valuation methodologies that result in management’s best estimate of fair value. Financial Assets and Liabilities Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The following tables set forth by level, within the fair value hierarchy, the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis: Fair value at June 30, 2017 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 142 $ — $ — $ 142 Commodity derivative instruments (see Note 5) — 43,685 — 43,685 Total assets $ 142 $ 43,685 $ — $ 43,827 Fair value at December 31, 2016 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 141 $ — $ — $ 141 Commodity derivative instruments (see Note 5) — 362 — 362 Total assets $ 141 $ 362 $ — $ 503 Liabilities: Commodity derivative instruments (see Note 5) $ — $ 72,183 $ — $ 72,183 Total liabilities $ — $ 72,183 $ — $ 72,183 The Level 1 instruments presented in the tables above consist of money market funds included in cash and cash equivalents on the Company’s Condensed Consolidated Balance Sheets at June 30, 2017 and December 31, 2016 . The Company’s money market funds represent cash equivalents backed by the assets of high-quality major banks and financial institutions. The Company identifies the money market funds as Level 1 instruments because the money market funds have daily liquidity, quoted prices for the underlying investments can be obtained, and there are active markets for the underlying investments. The Level 2 instruments presented in the tables above consist of commodity derivative instruments, which include oil and natural gas swaps and collars. The fair values of the Company’s commodity derivative instruments are based upon a third-party preparer’s calculation using mark-to-market valuation reports provided by the Company’s counterparties for monthly settlement purposes to determine the valuation of its derivative instruments. The Company has the third-party preparer evaluate other readily available market prices for its derivative contracts, as there is an active market for these contracts. The third-party preparer performs its independent valuation using a moment matching method similar to Turnbull-Wakeman for Asian options. The significant inputs used are crude oil prices, volatility, skew, discount rate and the contract terms of the derivative instruments. The Company compares the third-party preparer’s valuation to counterparty valuation statements, investigating any significant differences, and analyzes monthly valuation changes in relation to movements in crude oil and natural gas forward price curves. The determination of the fair value for derivative instruments also incorporates a credit adjustment for non-performance risk, as required by GAAP. The Company calculates the credit adjustment for derivatives in a net asset position using current credit default swap values for each counterparty. The credit adjustment for derivatives in a net liability position is based on the Company’s market credit spread. Based on these calculations, the Company recorded an adjustment to reduce the fair value of its net derivative asset by $41,000 at June 30, 2017 and an adjustment to reduce the fair value of its net derivative liability by $2.0 million at December 31, 2016 . There were no transfers between fair value levels during the six months ended June 30, 2017 and 2016 .

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments The Company utilizes derivative financial instruments to manage risks related to changes in oil and natural gas prices. The Company’s crude oil and natural gas contracts will settle monthly based on the average NYMEX West Texas Intermediate crude oil index price (“WTI”) and the average NYMEX Henry Hub natural gas index price (“Henry Hub”), respectively. At June 30, 2017 , the Company utilized swaps and two-way and three-way costless collar options to reduce the volatility of oil and natural gas prices on a significant portion of its future expected oil and natural gas production. A swap is a sold call and a purchased put established at the same price (both ceiling and floor), which the Company will receive for the volumes under contract. A two-way collar is a combination of options: a sold call and a purchased put. The purchased put establishes a minimum price (floor) and the sold call establishes a maximum price (ceiling) the Company will receive for the volumes under contract. A three-way collar is a combination of options: a sold call, a purchased put and a sold put. The purchased put establishes a minimum price (floor), unless the market price falls below the sold put (sub-floor), at which point the minimum price would be the NYMEX index price plus the difference between the purchased put and the sold put strike price. The sold call establishes a maximum price (ceiling) the Company will receive for the volumes under contract. All derivative instruments are recorded on the Company’s Condensed Consolidated Balance Sheets as either assets or liabilities measured at fair value (see Note 4 – Fair Value Measurements). The Company has not designated any derivative instruments as hedges for accounting purposes and does not enter into such instruments for speculative trading purposes. If a derivative does not qualify as a hedge or is not designated as a hedge, the changes in fair value are recognized in the other income (expense) section of the Company’s Condensed Consolidated Statements of Operations as a net gain or loss on derivative instruments. The Company’s cash flow is only impacted when the actual settlements under the derivative contracts result in making a payment to or receiving a payment from the counterparty. These cash settlements represent the cumulative gains and losses on the Company’s derivative instruments and do not include a recovery of costs that were paid to acquire or modify the derivative instruments that were settled. Cash settlements are reflected as investing activities in the Company’s Condensed Consolidated Statements of Cash Flows. At June 30, 2017 , the Company had the following outstanding commodity derivative instruments: Commodity Settlement Derivative Volumes Weighted Average Prices Fair Value Swap Sub-Floor Floor Ceiling (In thousands) Crude oil 2017 Swaps 3,843,000 Bbl $ 49.83 $ 13,211 Crude oil 2017 Two-way collar 1,464,000 Bbl $ 46.25 $ 54.37 3,122 Crude oil 2017 Three-way collar 1,098,000 Bbl $ 31.67 $ 45.83 $ 59.94 1,816 Crude oil 2018 Swaps 5,508,000 Bbl $ 51.95 20,746 Crude oil 2018 Two-way collar 582,000 Bbl $ 48.40 $ 55.13 1,799 Crude oil 2018 Three-way collar 186,000 Bbl $ 31.67 $ 45.83 $ 59.94 452 Crude oil 2019 Swaps 434,000 Bbl $ 52.16 1,365 Crude oil 2019 Two-way collar 31,000 Bbl $ 50.00 $ 55.70 104 Natural gas 2017 Swaps 3,680,000 MMBtu $ 3.32 827 Natural gas 2018 Swaps 5,475,000 MMBtu $ 3.04 243 $ 43,685 The following table summarizes the location and amounts of gains and losses from the Company’s commodity derivative instruments recorded in the Company’s Condensed Consolidated Statements of Operations for the periods presented: Three Months Ended June 30, Six Months Ended June 30, Statement of Operations Location 2017 2016 2017 2016 (In thousands) Net gain (loss) on derivative instruments $ 50,532 $ (90,846 ) $ 106,607 $ (76,471 ) In accordance with the FASB’s authoritative guidance on disclosures about offsetting assets and liabilities, the Company is required to disclose both gross and net information about instruments and transactions eligible for offset in the statement of financial position as well as instruments and transactions subject to an agreement similar to a master netting agreement. The Company’s derivative instruments are presented as assets and liabilities on a net basis by counterparty, as all counterparty contracts provide for net settlement. No margin or collateral balances are deposited with counterparties, and as such, gross amounts are offset to determine the net amounts presented in the Company’s Condensed Consolidated Balance Sheets. The following table summarizes the location and fair value of all outstanding commodity derivative instruments recorded in the Company’s Condensed Consolidated Balance Sheets: June 30, 2017 Commodity Balance Sheet Location Gross Recognized Assets Gross Amount Offset Net Recognized Fair Value Assets (In thousands) Derivatives assets: Commodity contracts Derivative instruments — current assets $ 37,829 $ (5,978 ) $ 31,851 Commodity contracts Derivative instruments — non-current assets 12,482 (648 ) 11,834 Total derivatives assets $ 50,311 $ (6,626 ) $ 43,685 December 31, 2016 Commodity Balance Sheet Location Gross Recognized Asset/Liabilities Gross Amount Offset Net Recognized Fair Value Asset/Liabilities (In thousands) Derivatives assets: Commodity contracts Derivative instruments — current assets $ 482 $ (120 ) $ 362 Total derivatives assets $ 482 $ (120 ) $ 362 Derivatives liabilities: Commodity contracts Derivative instruments — current liabilities $ 66,838 $ (6,369 ) $ 60,469 Commodity contracts Derivative instruments — non-current liabilities 14,164 (2,450 ) 11,714 Total derivatives liabilities $ 81,002 $ (8,819 ) $ 72,183

Property, Plant and Equipment

Property, Plant and Equipment	6 Months Ended
	Jun. 30, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment The following table sets forth the Company’s property, plant and equipment: June 30, 2017 December 31, 2016 (In thousands) Proved oil and gas properties (1) $ 6,671,833 $ 6,476,833 Less: accumulated depreciation, depletion, amortization and impairment (2,130,330 ) (1,886,732 ) Proved oil and gas properties, net 4,541,503 4,590,101 Unproved oil and gas properties 816,242 819,735 Other property and equipment 695,592 618,790 Less: accumulated depreciation (122,323 ) (109,059 ) Other property and equipment, net 573,269 509,731 Total property, plant and equipment, net $ 5,931,014 $ 5,919,567 __________________ (1) Included in the Company’s proved oil and gas properties are estimates of future asset retirement costs of $43.3 million and $42.9 million at June 30, 2017 and December 31, 2016 , respectively. Midstream assets acquisition. On April 25, 2017, the Company completed purchase and sale agreements with two undisclosed private sellers to acquire certain midstream assets in McKenzie County, North Dakota for total consideration of $12.7 million , which includes $4.9 million of installment notes payable. Based on the FASB’s authoritative guidance, the acquisition qualified as a business combination, and as such, the Company estimated the fair value of the assets acquired as of the acquisition date. The Company recorded the assets acquired at their estimated fair value of $12.7 million , which the Company considers to be representative of the price paid by a typical market participant. This measurement resulted in no goodwill or bargain purchase being recognized. The results of operations for the acquisition have been included in the Company’s condensed consolidated financial statements since the closing date. Pro forma information is not presented as the pro forma results would not be materially different from the information presented in the Company’s Condensed Consolidated Statement of Operations.

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt The Company’s long-term debt consists of the following: June 30, 2017 December 31, 2016 (In thousands) Senior secured revolving line of credit $ 418,000 $ 363,000 Senior unsecured notes 7.25% senior unsecured notes due February 1, 2019 54,275 54,275 6.5% senior unsecured notes due November 1, 2021 395,501 395,501 6.875% senior unsecured notes due March 15, 2022 937,080 937,080 6.875% senior unsecured notes due January 15, 2023 366,094 366,094 2.625% senior unsecured convertible notes due September 15, 2023 300,000 300,000 Total principal of senior unsecured notes 2,052,950 2,052,950 Less: unamortized deferred financing costs on senior unsecured notes (25,634 ) (28,268 ) Less: unamortized debt discount on senior unsecured convertible notes (85,633 ) (90,468 ) Total long-term debt $ 2,359,683 $ 2,297,214 The carrying amount of the Company’s long-term debt reported in the Condensed Consolidated Balance Sheet at June 30, 2017 was $2,359.7 million , which included $2,053.0 million of senior unsecured notes, a reduction for the unamortized debt discount related to the equity component of the senior unsecured convertible notes and a reduction for the unamortized deferred financing costs on the senior unsecured notes of $85.6 million and $25.6 million , respectively, and $418.0 million of borrowings under the revolving credit facility. The Company’s revolving credit facility is recorded at a value that approximates its fair value since its variable interest rate is tied to current market rates. The fair value of the Company’s senior unsecured notes, which are publicly traded and therefore categorized as Level 1 liabilities, was $1,994.8 million at June 30, 2017 . Senior secured revolving line of credit. The Company has a senior secured revolving line of credit (the “Credit Facility”) of $2,500.0 million as of June 30, 2017 , which has a maturity date of April 13, 2020, provided that the 7.25% senior unsecured notes due February 1, 2019 (the “2019 Notes”), of which $54.3 million is outstanding, are retired or refinanced 90 days prior to their maturity. The Credit Facility is restricted to a borrowing base, which is reserve-based and subject to semi-annual redeterminations on April 1 and October 1 of each year. On April 10, 2017 , the lenders under the Credit Facility (the “Lenders”) completed their regular semi-annual redetermination of the borrowing base scheduled for April 1, 2017, resulting in an increase in the borrowing base from $1,150.0 million to $1,600.0 million ; however, the Company elected to limit the Lenders’ aggregate commitment to $1,150.0 million . At June 30, 2017 , the Company had $418.0 million of LIBOR loans at a weighted average interest rate of 3.0% and $10.0 million of outstanding letters of credit issued under the Credit Facility, resulting in an unused borrowing base committed capacity of $722.0 million . On a quarterly basis, the Company also pays a 0.375% (as of June 30, 2017 ) annualized commitment fee on the average amount of borrowing base capacity not utilized during the quarter and fees calculated on the average amount of letter of credit balances outstanding during the quarter. The Company was in compliance with the financial covenants of the Credit Facility as of June 30, 2017 . Senior unsecured notes. At June 30, 2017 , the Company had $1,753.0 million principal amount of senior unsecured notes outstanding with maturities ranging from February 2019 to January 2023 and coupons ranging from 6.50% to 7.25% (the “Senior Notes”). Prior to certain dates, the Company has the option to redeem some or all of the Senior Notes for cash at certain redemption prices equal to a certain percentage of their principal amount plus an applicable make-whole premium and accrued and unpaid interest to the redemption date. The 2019 Notes are currently redeemable for cash at a redemption price equal to par plus accrued and unpaid interest to the redemption date. Senior unsecured convertible notes. In September 2016, the Company issued $300.0 million of 2.625% senior unsecured convertible notes due September 2023 (the “Senior Convertible Notes”). The Company has the option to settle conversions of these notes with cash, shares of common stock or a combination of cash and common stock at its election. The Company’s intent is to settle the principal amount of the Senior Convertible Notes in cash upon conversion. Prior to March 15, 2023, the Senior Convertible Notes will be convertible only under the following circumstances: (i) during any calendar quarter (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (ii) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price per $1,000 principal amount of the Senior Convertible Notes for each trading day of the measurement period is less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; or (iii) upon the occurrence of specified corporate events, including certain distributions or a fundamental change. On or after March 15, 2023, the Senior Convertible Notes will be convertible at any time until the second scheduled trading day immediately preceding their September 15, 2023 maturity date. The Senior Convertible Notes will be convertible at an initial conversion rate of 76.3650 shares of the Company’s common stock per $1,000 principal amount of the Senior Convertible Notes, which is equivalent to an initial conversion price of approximately $13.10 . The conversion rate will be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date or a notice of redemption, the Company will increase the conversion rate for a holder who elects to convert its Senior Convertible Notes in connection with such corporate event or redemption in certain circumstances. As of June 30, 2017 , none of the contingent conditions allowing holders of the Senior Convertible Notes to convert these notes had been met. Upon issuance, the Company separately accounted for the liability and equity components of the Senior Convertible Notes in accordance with Accounting Standards Codification 470-20. The liability component was recorded at the estimated fair value of a similar debt instrument without the conversion feature. The difference between the principal amount of the Senior Convertible Notes and the estimated fair value of the liability component was recorded as a debt discount and will be amortized to interest expense over the term of the notes using the effective interest method, with an effective interest rate of 8.97% per annum. The fair value of the Senior Convertible Notes as of the issuance date was estimated at $206.8 million , resulting in a debt discount at inception of $93.2 million . The equity component, representing the value of the conversion option, was computed by deducting the fair value of the liability component from the initial proceeds of the Senior Convertible Notes issuance. This equity component was recorded, net of deferred taxes and issuance costs, in additional paid-in capital and will not be remeasured as long as it continues to meet the conditions for equity classification. Interest on the Senior Notes and the Senior Convertible Notes (collectively, the “Notes”) is payable semi-annually in arrears. The Notes are guaranteed on a senior unsecured basis by the Company, along with its material subsidiaries (the “Guarantors”), which are 100% owned by the Company. These guarantees are full and unconditional and joint and several among the Guarantors, subject to certain customary release provisions. The indentures governing the Notes contain customary events of default as well as covenants that place restrictions on the Company and certain of its subsidiaries.

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2017
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The following table reflects the changes in the Company’s ARO during the six months ended June 30, 2017 : (In thousands) Balance at December 31, 2016 $ 49,687 Liabilities incurred during period 661 Liabilities settled during period (101 ) Accretion expense during period (1) 1,316 Revisions to estimates (214 ) Balance at June 30, 2017 $ 51,349 ___________________ (1) Included in depreciation, depletion and amortization on the Company’s Condensed Consolidated Statements of Operations. At June 30, 2017 , the current portion of the total ARO balance was approximately $0.3 million and was included in accrued liabilities on the Company’s Condensed Consolidated Balance Sheet.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s effective tax rate for the three and six months ended June 30, 2017 was 12.4% and 31.3% , respectively. The effective tax rate for the three and six months ended June 30, 2017 was lower than the combined federal statutory rate and the statutory rates for the states in which the Company conducts business due to the impact of permanent differences and a forecasted annual pre-tax loss for 2017. The Company’s effective tax rate for the three and six months ended June 30, 2016 was 36.9% and 34.2% , respectively. The effective tax rate for the three and six months ended June 30, 2016 was lower than the combined federal statutory rate and the statutory rates for the states in which the Company conducts business due to the impact of permanent differences on pre-tax loss for the period. During both the three and six months ended June 30, 2017 and 2016 , the permanent differences were primarily between amounts expensed for book purposes versus the amounts deductible for income tax purposes related to compensation.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Restricted stock awards. The Company has granted restricted stock awards to employees and directors under its Amended and Restated 2010 Long Term Incentive Plan, the majority of which vest over a three -year period. The fair value of restricted stock awards is based on the closing sales price of the Company’s common stock on the date of grant. Compensation expense is recognized ratably over the requisite service period. During the six months ended June 30, 2017 , employees and non-employee directors of the Company were granted restricted stock awards equal to 1,588,010 shares of common stock with a $15.24 weighted average grant date per share value. Stock-based compensation expense recorded for restricted stock awards for the three and six months ended June 30, 2017 was $4.9 million and $10.3 million , respectively, and $4.9 million and $10.7 million for the three and six months ended June 30, 2016 , respectively. Stock-based compensation expense is included in general and administrative expenses on the Company’s Condensed Consolidated Statements of Operations. Performance share units. The Company has granted performance share units (“PSUs”) to officers of the Company under its Amended and Restated 2010 Long Term Incentive Plan. The PSUs are awards of restricted stock units, and each PSU that is earned represents the right to receive one share of the Company’s common stock. During the six months ended June 30, 2017 , officers of the Company were granted 509,800 PSUs with a $16.89 weighted average grant date per share value. Stock-based compensation expense recorded for PSUs for the three and six months ended June 30, 2017 was $2.2 million and $3.5 million , respectively, and $1.3 million and $2.2 million for the three and six months ended June 30, 2016 , respectively. Stock-based compensation expense is included in general and administrative expenses on the Company’s Condensed Consolidated Statements of Operations. The Company accounted for these PSUs as equity awards pursuant to the FASB’s authoritative guidance for share-based payments. The number of PSUs to be earned is subject to a market condition, which is based on a comparison of the total shareholder return (“TSR”) achieved with respect to shares of the Company’s common stock against the TSR achieved by a defined peer group at the end of the performance periods. Depending on the Company’s TSR performance relative to the defined peer group, award recipients will earn between 0% and 200% of the initial PSUs granted. All compensation expense related to the PSUs will be recognized if the requisite performance period is fulfilled, even if the market condition is not achieved. The aggregate grant date fair value of the market-based awards was determined using a Monte Carlo simulation model. The Monte Carlo simulation model uses assumptions regarding random projections and must be repeated numerous times to achieve a probabilistic assessment. The key valuation assumptions for the Monte Carlo model are the forecast period, initial value, risk-free interest rate, volatility and correlation coefficients. The risk-free interest rates are the U.S. Treasury bond rates on the date of grant that correspond to each performance period. The initial value is the average of the volume weighted average prices for the 30 trading days prior to the start of the performance cycle for the Company and each of its peers. Volatility was calculated from the daily historical returns of 30 -day volume weighted average stock prices over a historical period for the Company and each of its peers. The correlation coefficients are measures of the strength of the linear relationship between and amongst the Company and its peers estimated based on historical stock price data. The following assumptions were used for the Monte Carlo model to determine the grant date fair value and associated stock-based compensation expense of the PSUs granted during the six months ended June 30, 2017 : Risk-free interest rate 1.18% - 1.66% Oasis volatility 17.16 %

Earnings (Loss) Per Share

Earnings (Loss) Per Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings (Loss) Per Share Basic earnings (loss) per share is computed by dividing the earnings (loss) attributable to common stockholders by the weighted average number of shares outstanding for the periods presented. The calculation of diluted earnings (loss) per share includes the potential dilutive impact of unvested restricted stock awards and contingently issuable shares related to PSUs and senior convertible notes during the periods presented, unless their effect is anti-dilutive. There are no adjustments made to the income (loss) available to common stockholders in the calculation of diluted earnings (loss) per share. The following is a calculation of the basic and diluted weighted average shares outstanding for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (In thousands) Basic weighted average common shares outstanding 233,283 176,984 233,176 169,953 Dilutive effect of restricted stock awards and PSUs (1) 1,634 — 3,105 — Diluted weighted average common shares outstanding 234,917 176,984 236,281 169,953 __________________ (1) No unvested stock awards were included in computing loss per share for the three and six months ended June 30, 2016 because the effect was anti-dilutive. The following is a calculation of weighted average common shares excluded from diluted earnings (loss) per share due to the anti-dilutive effect: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (In thousands) Restricted stock awards and PSUs 4,369 4,920 2,957 4,794 The Company issued its Senior Convertible Notes in September 2016 (see Note 7 – Long-Term Debt). The Company has the option to settle conversions of its Senior Convertible Notes with cash, shares of common stock or a combination of cash and common stock at its election. The Company’s intent is to settle the principal amount of the Senior Convertible Notes in cash upon conversion. As a result, only the amount by which the conversion value exceeds the aggregate principal amount of the notes (conversion spread) is considered in the diluted earnings per share computation under the treasury stock method. As of the three and six months ended June 30, 2017 , the conversion value did not exceed the principal amount of the notes, and accordingly, there was no impact to diluted earnings per share for the three and six months ended June 30, 2017 .

Business Segment Information

Business Segment Information	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Business Segment Information	Business Segment Information The Company’s exploration and production segment is engaged in the acquisition and development of oil and natural gas properties. Revenues for the exploration and production segment are derived from the sale of oil and natural gas production. The Company’s midstream services business segment (OMS) performs salt water gathering and disposal services, fresh water services, natural gas gathering and processing and crude oil gathering and transportation and other midstream services for the Company’s oil and natural gas wells operated by OPNA. Revenues for the midstream segment are primarily derived from salt water pipeline transport, salt water disposal, fresh water sales, natural gas gathering and processing and crude oil gathering, blending, stabilization and transportation. The Company’s well services business segment (OWS) performs completion services for the Company’s oil and natural gas wells operated by OPNA. Revenues for the well services segment are derived from providing well services, product sales and equipment rentals. The revenues and expenses related to work performed by OMS and OWS for OPNA’s working interests are eliminated in consolidation, and only the revenues and expenses related to non-affiliated working interest owners are included in the Company’s Condensed Consolidated Statements of Operations. These segments represent the Company’s three operating units, each offering different products and services. The Company’s corporate activities have been allocated to the supported business segments accordingly. Management evaluates the performance of the Company’s business segments based on operating income. The following table summarizes financial information for the Company’s three business segments for the periods presented: Exploration and Production Midstream Services Well Services Eliminations Consolidated (In thousands) Three months ended June 30, 2017: Revenues from non-affiliates $ 226,724 $ 15,566 $ 11,801 $ — $ 254,091 Inter-segment revenues — 24,746 21,650 (46,396 ) — Total revenues 226,724 40,312 33,451 (46,396 ) 254,091 Operating income (loss) (17,425 ) 23,103 1,950 (2,249 ) 5,379 Other income 13,525 3 — — 13,528 Income (loss) before income taxes $ (3,900 ) $ 23,106 $ 1,950 $ (2,249 ) $ 18,907 Three months ended June 30, 2016: Revenues from non-affiliates $ 159,337 $ 6,910 $ 12,833 $ — $ 179,080 Inter-segment revenues — 22,025 8,302 (30,327 ) — Total revenues 159,337 28,935 21,135 (30,327 ) 179,080 Operating income (loss) (44,748 ) 18,056 (2,173 ) 651 (28,214 ) Other income (expense) (114,230 ) (16 ) 31 — (114,215 ) Income (loss) before income taxes $ (158,978 ) $ 18,040 $ (2,142 ) $ 651 $ (142,429 ) Six months ended June 30, 2017: Revenues from non-affiliates $ 491,607 $ 30,172 $ 17,428 $ — $ 539,207 Inter-segment revenues — 47,781 37,003 (84,784 ) — Total revenues 491,607 77,953 54,431 (84,784 ) 539,207 Operating income (loss) (16,456 ) 43,865 (1,641 ) (297 ) 25,471 Other income 33,292 2 4 — 33,298 Income (loss) before income taxes $ 16,836 $ 43,867 $ (1,637 ) $ (297 ) $ 58,769 Six months ended June 30, 2016: Revenues from non-affiliates $ 276,652 $ 13,893 $ 18,818 $ — $ 309,363 Inter-segment revenues — 44,860 33,205 (78,065 ) — Total revenues 276,652 58,753 52,023 (78,065 ) 309,363 Operating income (loss) (133,625 ) 33,200 1,848 (4,852 ) (103,429 ) Other income (expense) (131,119 ) (2 ) 37 — (131,084 ) Income (loss) before income taxes $ (264,744 ) $ 33,198 $ 1,885 $ (4,852 ) $ (234,513 ) At June 30, 2017: Property, plant and equipment, net $ 5,567,347 $ 495,112 $ 41,228 $ (172,673 ) $ 5,931,014 Total assets (1) 5,881,351 504,119 48,924 (172,673 ) 6,261,721 At December 31, 2016: Property, plant and equipment, net $ 5,620,558 $ 424,197 $ 47,189 $ (172,377 ) $ 5,919,567 Total assets (1) 5,868,747 431,095 51,167 (172,377 ) 6,178,632 ___________________ (1) Intercompany receivables (payables) for all segments were reclassified to capital contributions from (distributions to) parent and not included in total assets.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company has various contractual obligations in the normal course of its operations. As of June 30, 2017 , there have been no material changes to the Company’s future commitments as disclosed in Note 16 in the Company’s 2016 Annual Report. Litigation. The Company is party to various legal and/or regulatory proceedings from time to time arising in the ordinary course of business. When the Company determines that a loss is probable of occurring and is reasonably estimable, the Company accrues an undiscounted liability for such contingencies based on its best estimate using information available at the time. The Company discloses contingencies where an adverse outcome may be material, or in the judgment of management, the matter should otherwise be disclosed. Mirada litigation. On March 23, 2017, Mirada Energy, LLC, Mirada Wild Basin Holding Company, LLC and Mirada Energy Fund I, LLC (collectively, “Mirada”) filed a lawsuit against Oasis, OPNA and OMS, seeking monetary damages in excess of $100 million , declaratory relief, attorneys’ fees and costs (Mirada Energy, LLC, et al. v. Oasis Petroleum North America LLC, et al.; in the 334th Judicial District Court of Harris County, Texas; Case Number 2017-19911). Mirada asserts that it is a working interest owner in certain acreage owned and operated by the Company in Wild Basin. Specifically, Mirada asserts that the Company has breached certain agreements by: (1) failing to allow Mirada to participate in the Company’s midstream operations in Wild Basin; (2) refusing to provide Mirada with information that Mirada contends is required under certain agreements and failing to provide information in a timely fashion; (3) failing to consult with Mirada and failing to obtain Mirada’s consent prior to drilling more than one well at a time in Wild Basin; and (4) by overstating the estimated costs of proposed well operations in Wild Basin. Mirada seeks a declaratory judgment that the Company be removed as operator in Wild Basin at Mirada’s election and that Mirada be allowed to elect a new operator; certain agreements apply to the Company and Mirada and Wild Basin with respect to this dispute; the Company be required to provide all information within its possession regarding proposed or ongoing operations in Wild Basin; and the Company not be permitted to drill, or propose to drill, more than one well at a time in Wild Basin without obtaining Mirada’s consent. Mirada also seeks a declaratory judgment with respect to the Company’s current midstream operations in Wild Basin. Specifically, Mirada seeks a declaratory judgment that Mirada has a right to participate in the Company’s Wild Basin midstream operations, consisting of produced water disposal, crude oil gathering and gas gathering and processing; that, upon Mirada’s election to participate, Mirada is obligated to pay its proportionate costs of the Company’s midstream operations in Wild Basin; and that Mirada would then be entitled to receive a share of revenues from the midstream operations and would not be charged any amount for its use of these facilities for production from the “Contract Area.” On June 30, 2017, Mirada amended its original petition to add a claim that the Company has breached certain agreements by charging Mirada for midstream services provided by its affiliates and to seek a declaratory judgment that Mirada is entitled to be paid its share of total proceeds from the sale of hydrocarbons received by OPNA or any affiliate of OPNA without deductions for midstream services provided by OPNA or its affiliates. The Company believes that Mirada’s claims are without merit, that the Company has complied with its obligations under the applicable agreements and that some of Mirada’s claims are grounded in agreements which do not apply to the Company. The Company filed an answer denying Mirada’s claims on April 21, 2017, and intends to vigorously defend against Mirada’s claims. Discovery is ongoing, and trial is currently scheduled for July 2018. However, the Company cannot predict or guarantee the ultimate outcome or resolution of such matter. If such matter were to be determined adversely to the Company’s interests, or if the Company were forced to settle such matter for a significant amount, such resolution or settlement could have a material adverse effect on the Company’s business, results of operations and financial condition. Such an adverse determination could materially impact the Company’s ability to operate its properties in Wild Basin or develop its identified drilling locations in Wild Basin on its current development schedule. A determination that Mirada has a right to participate in the Company’s midstream operations could materially reduce the interests of the Company in their current assets and future midstream opportunities and related revenues in Wild Basin.

Condensed Consolidating Financi

Condensed Consolidating Financial Information	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Financial Information	Condensed Consolidating Financial Information The Notes (see Note 7 – Long-Term Debt) are guaranteed on a senior unsecured basis by the Guarantors, which are 100% owned by the Company. These guarantees are full and unconditional and joint and several among the Guarantors. Certain of the Company’s immaterial wholly-owned subsidiaries do not guarantee the Notes (“Non-Guarantor Subsidiaries”). The following financial information reflects consolidating financial information of the parent company, Oasis Petroleum Inc. (“Issuer”), and its Guarantors on a combined basis, prepared on the equity basis of accounting. The Non-Guarantor Subsidiaries are immaterial and, therefore, not presented separately. The information is presented in accordance with the requirements of Rule 3-10 under the SEC’s Regulation S-X. The financial information may not necessarily be indicative of results of operations, cash flows or financial position had the Guarantors operated as independent entities. The Company has not presented separate financial and narrative information for each of the Guarantors because it believes such financial and narrative information would not provide any additional information that would be material in evaluating the sufficiency of the Guarantors. Condensed Consolidating Balance Sheet June 30, 2017 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 178 $ 11,262 $ — $ 11,440 Accounts receivable, net — 218,302 — 218,302 Accounts receivable - affiliates 187,496 33,709 (221,205 ) — Inventory — 17,942 — 17,942 Prepaid expenses 664 9,946 — 10,610 Derivative instruments — 31,851 — 31,851 Other current assets 3 59 — 62 Total current assets 188,341 323,071 (221,205 ) 290,207 Property, plant and equipment Oil and gas properties (successful efforts method) — 7,488,075 — 7,488,075 Other property and equipment — 695,592 — 695,592 Less: accumulated depreciation, depletion, amortization and impairment — (2,252,653 ) — (2,252,653 ) Total property, plant and equipment, net — 5,931,014 — 5,931,014 Investments in and advances to subsidiaries 4,545,805 — (4,545,805 ) — Derivative instruments — 11,834 — 11,834 Deferred income taxes 257,652 — (257,652 ) — Long-term inventory — 8,762 — 8,762 Other assets — 19,904 — 19,904 Total assets $ 4,991,798 $ 6,294,585 $ (5,024,662 ) $ 6,261,721 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities Accounts payable $ — $ 12,257 $ — $ 12,257 Accounts payable - affiliates 33,709 187,496 (221,205 ) — Revenues and production taxes payable — 143,715 — 143,715 Accrued liabilities — 139,766 — 139,766 Accrued interest payable 38,796 332 — 39,128 Advances from joint interest partners — 5,816 — 5,816 Total current liabilities 72,505 489,382 (221,205 ) 340,682 Long-term debt 1,941,683 418,000 — 2,359,683 Deferred income taxes — 784,833 (257,652 ) 527,181 Asset retirement obligations — 51,059 — 51,059 Other liabilities — 5,506 — 5,506 Total liabilities 2,014,188 1,748,780 (478,857 ) 3,284,111 Stockholders’ equity Capital contributions from affiliates — 3,395,528 (3,395,528 ) — Common stock, $0.01 par value: 450,000,000 shares authorized; 238,642,598 shares issued and 237,410,395 shares outstanding 2,345 — — 2,345 Treasury stock, at cost: 1,232,203 shares (21,401 ) — — (21,401 ) Additional paid-in-capital 2,362,084 8,743 (8,743 ) 2,362,084 Retained earnings 634,582 1,141,534 (1,141,534 ) 634,582 Total stockholders’ equity 2,977,610 4,545,805 (4,545,805 ) 2,977,610 Total liabilities and stockholders’ equity $ 4,991,798 $ 6,294,585 $ (5,024,662 ) $ 6,261,721 Condensed Consolidating Balance Sheet December 31, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 166 $ 11,060 $ — $ 11,226 Accounts receivable, net — 204,335 — 204,335 Accounts receivable - affiliates 252,000 27,619 (279,619 ) — Inventory — 10,648 — 10,648 Prepaid expenses 275 7,348 — 7,623 Derivative instruments — 362 — 362 Other current assets — 4,355 — 4,355 Total current assets 252,441 265,727 (279,619 ) 238,549 Property, plant and equipment Oil and gas properties (successful efforts method) — 7,296,568 — 7,296,568 Other property and equipment — 618,790 — 618,790 Less: accumulated depreciation, depletion, amortization and impairment — (1,995,791 ) — (1,995,791 ) Total property, plant and equipment, net — 5,919,567 — 5,919,567 Investments in and advances to subsidiaries 4,451,192 — (4,451,192 ) — Derivative instruments — — — — Deferred income taxes 220,058 — (220,058 ) — Other assets — 20,516 — 20,516 Total assets $ 4,923,691 $ 6,205,810 $ (4,950,869 ) $ 6,178,632 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities Accounts payable $ — $ 4,645 $ — $ 4,645 Accounts payable - affiliates 27,619 252,000 (279,619 ) — Revenues and production taxes payable — 139,737 — 139,737 Accrued liabilities 12 119,161 — 119,173 Accrued interest payable 38,689 315 — 39,004 Derivative instruments — 60,469 — 60,469 Advances from joint interest partners — 7,597 — 7,597 Other current liabilities — 10,490 — 10,490 Total current liabilities 66,320 594,414 (279,619 ) 381,115 Long-term debt 1,934,214 363,000 — 2,297,214 Deferred income taxes — 733,587 (220,058 ) 513,529 Asset retirement obligations — 48,985 — 48,985 Derivative instruments — 11,714 — 11,714 Other liabilities — 2,918 — 2,918 Total liabilities 2,000,534 1,754,618 (499,677 ) 3,255,475 Stockholders’ equity Capital contributions from affiliates — 3,388,893 (3,388,893 ) — Common stock, $0.01 par value: 450,000,000 shares authorized; 237,201,064 shares issued and 236,344,172 shares outstanding 2,331 — — 2,331 Treasury stock, at cost: 856,892 shares (15,950 ) — — (15,950 ) Additional paid-in-capital 2,345,271 8,743 (8,743 ) 2,345,271 Retained earnings 591,505 1,053,556 (1,053,556 ) 591,505 Total stockholders’ equity 2,923,157 4,451,192 (4,451,192 ) 2,923,157 Total liabilities and stockholders’ equity $ 4,923,691 $ 6,205,810 $ (4,950,869 ) $ 6,178,632 Condensed Consolidating Statement of Operations Three Months Ended June 30, 2017 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 218,633 $ — $ 218,633 Bulk oil sales — 8,091 — 8,091 Midstream revenues — 15,566 — 15,566 Well services revenues — 11,801 — 11,801 Total revenues — 254,091 — 254,091 Operating expenses Lease operating expenses — 44,665 — 44,665 Midstream operating expenses — 3,263 — 3,263 Well services operating expenses — 8,088 — 8,088 Marketing, transportation and gathering expenses — 12,039 — 12,039 Bulk oil purchases — 7,980 — 7,980 Production taxes — 18,971 — 18,971 Depreciation, depletion and amortization — 125,291 — 125,291 Exploration expenses — 1,667 — 1,667 Impairment — 3,200 — 3,200 General and administrative expenses 7,534 16,014 — 23,548 Total operating expenses 7,534 241,178 — 248,712 Operating income (loss) (7,534 ) 12,913 — 5,379 Other income (expense) Equity in earnings of subsidiaries 38,875 — (38,875 ) — Net gain on derivative instruments — 50,532 — 50,532 Interest expense, net of capitalized interest (33,006 ) (3,832 ) — (36,838 ) Other expense — (166 ) — (166 ) Total other income 5,869 46,534 (38,875 ) 13,528 Income (loss) before income taxes (1,665 ) 59,447 (38,875 ) 18,907 Income tax benefit (expense) 18,233 (20,572 ) — (2,339 ) Net income $ 16,568 $ 38,875 $ (38,875 ) $ 16,568 Condensed Consolidating Statement of Operations Three Months Ended June 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 159,337 $ — $ 159,337 Midstream revenues — 6,910 — 6,910 Well services revenues — 12,833 — 12,833 Total revenues — 179,080 — 179,080 Operating expenses Lease operating expenses — 31,523 — 31,523 Midstream operating expenses — 1,740 — 1,740 Well services operating expenses — 7,135 — 7,135 Marketing, transportation and gathering expenses — 6,491 — 6,491 Production taxes — 14,367 — 14,367 Depreciation, depletion and amortization — 122,488 — 122,488 Exploration expenses — 340 — 340 Impairment — 23 — 23 General and administrative expenses 6,395 15,481 — 21,876 Total operating expenses 6,395 199,588 — 205,983 Loss on sale of properties — (1,311 ) — (1,311 ) Operating loss (6,395 ) (21,819 ) — (28,214 ) Other income (expense) Equity in loss of subsidiaries (71,987 ) — 71,987 — Net loss on derivative instruments — (90,846 ) — (90,846 ) Interest expense, net of capitalized interest (33,190 ) (1,789 ) — (34,979 ) Gain on extinguishment of debt 11,642 — — 11,642 Other expense — (32 ) — (32 ) Total other expense (93,535 ) (92,667 ) 71,987 (114,215 ) Loss before income taxes (99,930 ) (114,486 ) 71,987 (142,429 ) Income tax benefit 9,999 42,499 — 52,498 Net loss $ (89,931 ) $ (71,987 ) $ 71,987 $ (89,931 ) Condensed Consolidating Statement of Operations Six Months Ended June 30, 2017 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 455,885 $ — $ 455,885 Bulk oil sales — 35,722 — 35,722 Midstream revenues — 30,172 — 30,172 Well services revenues — 17,428 — 17,428 Total revenues — 539,207 — 539,207 Operating expenses Lease operating expenses — 88,537 — 88,537 Midstream operating expenses — 6,590 — 6,590 Well services operating expenses — 11,990 — 11,990 Marketing, transportation and gathering expenses — 22,990 — 22,990 Bulk oil purchases — 35,982 — 35,982 Production taxes — 39,270 — 39,270 Depreciation, depletion and amortization — 251,957 — 251,957 Exploration expenses — 3,156 — 3,156 Impairment — 5,882 — 5,882 General and administrative expenses 14,599 32,783 — 47,382 Total operating expenses 14,599 499,137 — 513,736 Operating income (loss) (14,599 ) 40,070 — 25,471 Other income (expense) Equity in earnings of subsidiaries 87,978 — (87,978 ) — Net gain on derivative instruments — 106,607 — 106,607 Interest expense, net of capitalized interest (65,857 ) (7,302 ) — (73,159 ) Other expense — (150 ) — (150 ) Total other income 22,121 99,155 (87,978 ) 33,298 Income before income taxes 7,522 139,225 (87,978 ) 58,769 Income tax benefit (expense) 32,871 (51,247 ) — (18,376 ) Net income $ 40,393 $ 87,978 $ (87,978 ) $ 40,393 Condensed Consolidating Statement of Operations Six Months Ended June 30, 2016 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 276,652 $ — $ 276,652 Midstream revenues — 13,893 — 13,893 Well services revenues — 18,818 — 18,818 Total revenues — 309,363 — 309,363 Operating expenses Lease operating expenses — 62,587 — 62,587 Midstream operating expenses — 3,478 — 3,478 Well services operating expenses — 9,786 — 9,786 Marketing, transportation and gathering expenses — 15,043 — 15,043 Production taxes — 25,120 — 25,120 Depreciation, depletion and amortization — 244,937 — 244,937 Exploration expenses — 703 — 703 Impairment — 3,585 — 3,585 General and administrative expenses 13,846 32,396 — 46,242 Total operating expenses 13,846 397,635 — 411,481 Loss on sale of properties — (1,311 ) — (1,311 ) Operating loss (13,846 ) (89,583 ) — (103,429 ) Other income (expense) Equity in loss of subsidiaries (109,314 ) — 109,314 — Net loss on derivative instruments — (76,471 ) — (76,471 ) Interest expense, net of capitalized interest (68,022 ) (5,696 ) — (73,718 ) Gain on extinguishment of debt 18,658 — — 18,658 Other income 43 404 — 447 Total other expense (158,635 ) (81,763 ) 109,314 (131,084 ) Loss before income taxes (172,481 ) (171,346 ) 109,314 (234,513 ) Income tax benefit 18,095 62,032 — 80,127 Net loss $ (154,386 ) $ (109,314 ) $ 109,314 $ (154,386 ) Condensed Consolidating Statement of Cash Flows Six Months Ended June 30, 2017 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net income $ 40,393 $ 87,978 $ (87,978 ) $ 40,393 Adjustments to reconcile net income to net cash provided by operating activities: Equity in earnings of subsidiaries (87,978 ) — 87,978 — Depreciation, depletion and amortization — 251,957 — 251,957 Impairment — 5,882 — 5,882 Deferred income taxes (32,871 ) 51,247 — 18,376 Derivative instruments — (106,607 ) — (106,607 ) Stock-based compensation expenses 13,395 428 — 13,823 Deferred financing costs amortization and other 7,470 1,401 — 8,871 Working capital and other changes: Change in accounts receivable 64,504 (19,833 ) (58,414 ) (13,743 ) Change in inventory — (1,007 ) — (1,007 ) Change in prepaid expenses (389 ) 125 — (264 ) Change in other current assets (3 ) 283 — 280 Change in long-term inventory and other assets — (8,768 ) — (8,768 ) Change in accounts payable, interest payable and accrued liabilities 6,185 (53,441 ) 58,414 11,158 Change in other current liabilities — (10,490 ) — (10,490 ) Net cash provided by operating activities 10,706 199,155 — 209,861 Cash flows from investing activities: Capital expenditures — (252,461 ) — (252,461 ) Proceeds from sale of properties — 4,000 — 4,000 Derivative settlements — (8,899 ) — (8,899 ) Advances from joint interest partners — (1,781 ) — (1,781 ) Net cash used in investing activities — (259,141 ) — (259,141 ) Cash flows from financing activities: Proceeds from revolving credit facility — 484,000 — 484,000 Principal payments on revolving credit facility — (429,000 ) — (429,000 ) Purchases of treasury stock (5,451 ) — — (5,451 ) Investment in / capital contributions from subsidiaries (5,188 ) 5,188 — — Other (55 ) — — (55 ) Net cash provided by (used in) financing activities (10,694 ) 60,188 — 49,494 Increase in cash and cash equivalents 12 202 — 214 Cash and cash equivalents at beginning of period 166 11,060 — 11,226 Cash and cash equivalents at end of period $ 178 $ 11,262 $ — $ 11,440 Condensed Consolidating Statement of Cash Flows Six Months Ended June 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net loss $ (154,386 ) $ (109,314 ) $ 109,314 $ (154,386 ) Adjustments to reconcile net loss to net cash provided by (used in) operating activities: Equity in loss of subsidiaries 109,314 — (109,314 ) — Depreciation, depletion and amortization — 244,937 — 244,937 Gain on extinguishment of debt (18,658 ) — — (18,658 ) Loss on sale of properties — 1,311 — 1,311 Impairment — 3,585 — 3,585 Deferred income taxes (18,095 ) (62,032 ) — (80,127 ) Derivative instruments — 76,471 — 76,471 Stock-based compensation expenses 12,624 355 — 12,979 Deferred financing costs amortization and other 3,360 3,192 — 6,552 Working capital and other changes: Change in accounts receivable (85 ) 53,068 (48,686 ) 4,297 Change in inventory — 2,054 — 2,054 Change in prepaid expenses 278 1,145 — 1,423 Change in other current assets — (114 ) — (114 ) Change in long-term inventory and other assets 100 — — 100 Change in accounts payable, interest payable and accrued liabilities (50,462 ) (16,258 ) 48,686 (18,034 ) Change in other current liabilities — 9,001 — 9,001 Change in other liabilities — 10 — 10 Net cash provided by (used in) operating activities (116,010 ) 207,411 — 91,401 Cash flows from investing activities: Capital expenditures — (231,341 ) — (231,341 ) Proceeds from sale of properties — 11,679 — 11,679 Costs related to sale of properties — (310 ) — (310 ) Derivative settlements — 103,790 — 103,790 Advances from joint interest partners — 769 — 769 Net cash used in investing activities — (115,413 ) — (115,413 ) Cash flows from financing activities: Proceeds from revolving credit facility — 359,000 — 359,000 Principal payments on revolving credit facility — (462,000 ) — (462,000 ) Repurchase of senior unsecured notes (56,925 ) — — (56,925 ) Deferred financing costs — (751 ) — (751 ) Proceeds from sale of common stock 182,953 — — 182,953 Purchases of treasury stock (1,520 ) — — (1,520 ) Investment in / capital contributions from subsidiaries (9,190 ) 9,190 — — Net cash provided by (used in) financing activities 115,318 (94,561 ) — 20,757 Decrease in cash and cash equivalents (692 ) (2,563 ) — (3,255 ) Cash and cash equivalents at beginning of period 777 8,953 — 9,730 Cash and cash equivalents at end of period $ 85 $ 6,390 $ — $ 6,475

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated the period after the balance sheet date, noting no subsequent events or transactions that required recognition or disclosure in the financial statements, other than as noted below. Derivative instruments. In July and August 2017, the Company entered into new swaps and two-way costless collar options for crude oil which settle based on WTI. The commodity contracts included a total notional amount of 244,000 barrels with a weighted average floor price of $49.43 per barrel which settle in 2017 , 2,915,000 barrels with a weighted average floor price of $48.59 per barrel which settle in 2018 , and 248,000 barrels with a weighted average floor price of $48.49 per barrel which settle in 2019 . These derivative instruments do not qualify for or were not designated as hedging instruments for accounting purposes .

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements of the Company include the accounts of Oasis and its wholly-owned subsidiaries. All significant intercompany transactions have been eliminated in consolidation. The accompanying condensed consolidated financial statements of the Company have not been audited by the Company’s independent registered public accounting firm, except that the Condensed Consolidated Balance Sheet at December 31, 2016 is derived from audited financial statements. Certain reclassifications of prior year balances have been made to conform such amounts to current year classifications. These reclassifications have no impact on net income. In the opinion of management, all adjustments, consisting of normal recurring adjustments necessary for the fair statement, have been included. Management has made certain estimates and assumptions that affect reported amounts in the condensed consolidated financial statements and disclosures of contingencies. Actual results may differ from those estimates. The results for interim periods are not necessarily indicative of annual results. These interim financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain disclosures have been condensed or omitted from these financial statements. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete consolidated financial statements and should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 (“ 2016 Annual Report”).
Risks and Uncertainties	Risks and Uncertainties As an oil and natural gas producer, the Company’s revenue, profitability and future growth are substantially dependent upon the prevailing and future prices for oil and natural gas, which are dependent upon numerous factors beyond its control such as economic, political and regulatory developments and competition from other energy sources. The energy markets have historically been very volatile, and there can be no assurance that oil and natural gas prices will not be subject to wide fluctuations in the future. An extended period of low prices for oil and, to a lesser extent, natural gas could have a material adverse effect on the Company’s financial position, results of operations, cash flows and quantities of oil and natural gas reserves that may be economically produced.
Stock-based Compensation	Stock-based compensation. In the first quarter of 2017, the Company adopted Accounting Standards Update No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”), which updates several aspects of the accounting for share-based payment transactions, including recognition of excess tax benefits and deficiencies, the classification of those excess tax benefits on the statement of cash flows, an accounting policy election for forfeitures, the amount an employer can withhold to cover income taxes and still qualify for equity classification and the classification of those taxes paid on the statement of cash flows. In accordance with the new guidance, the Company recorded a $2.7 million cumulative-effect adjustment to retained earnings on the Company’s Condensed Consolidated Balance Sheet as of June 30, 2017 , which included recognition of excess tax benefits and deficiencies and the removal of the estimated forfeiture rate. ASU 2016-09 was applied on a modified retrospective basis and prior periods were not retrospectively adjusted.
Inventory	Inventory. In the first quarter of 2017, the Company adopted Accounting Standards Update No. 2015-11, Simplifying the Measurement of Inventory (“ASU 2015-11”), which changes the inventory measurement principle from lower of cost or market to lower of cost and net realizable value for entities using the first-in, first-out or average cost methods. ASU 2015-11 was applied on a prospective basis and prior periods were not retrospectively adjusted. There was no material impact as a result of adoption as of June 30, 2017 . Inventory , including long-term inventory, is stated at the lower of cost and net realizable value with cost determined on an average cost method. T he Company assesses the carrying value of inventory and uses estimates and judgment when making any adjustments necessary to reduce the carrying value to net realizable value. Among the uncertainties that impact the Company’s estimates are the applicable quality and location differentials to include in the Company’s net realizable value analysis. Additionally, the Company estimates the upcoming liquidation timing of the inventory. Changes in assumptions made as to the timing of a sale can materially impact net realizable value.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Revenue recognition. In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). The objective of ASU 2014-09 is greater consistency and comparability across industries by using a five-step model to recognize revenue from customer contracts. ASU 2014-09 also contains some new disclosure requirements under GAAP. In August 2015, the FASB issued Accounting Standards Update No. 2015-14, Deferral of the Effective Date (“ASU 2015-14”). ASU 2015-14 defers the effective date of the new revenue standard by one year, making it effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. In 2016, the FASB issued additional accounting standards updates to clarify the implementation guidance of ASU 2014-09. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Financial instruments. In January 2016, the FASB issued Accounting Standards Update No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which requires that most equity instruments be measured at fair value with subsequent changes in fair value recognized in net income. ASU 2016-01 also impacts financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. ASU 2016-01 does not apply to equity method investments or investments in consolidated subsidiaries. ASU 2016-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those years. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Leases. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (“ASU 2016-02”), which requires a lessee to recognize lease payment obligations and a corresponding right-of-use asset to be measured at fair value on the balance sheet. ASU 2016-02 also requires certain qualitative and quantitative disclosures about the amount, timing and uncertainty of cash flows arising from leases. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those years. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Statement of cash flows. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (“ASU 2016-15”), which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, including interim periods within those years. The adoption of this guidance will not impact the Company’s financial position or results of operations, but could result in presentation changes on the Company’s statement of cash flows. Business combinations. In January 2017, the FASB issued Accounting Standards Update No. 2017-01, Clarifying the Definition of a Business (“ASU 2017-01”), which provides guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. ASU 2017-01 requires entities to use a screen test to determine when an integrated set of assets and activities is not a business or if the integrated set of assets and activities needs to be further evaluated against the framework. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those years. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, cash flows and results of operations. Stock-based compensation. In May 2017, the FASB issued Accounting Standards Update No. 2017-09, Scope of Modification Accounting (“ASU 2017-09”), which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The adoption of ASU 2017-09 will become effective for annual periods beginning after December 15, 2017, and the Company is currently evaluating the impact that it will have on its financial position, cash flows and results of operations.

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jun. 30, 2017
Inventory Disclosure [Abstract]
Components of Inventory	Total inventory consists of the following: June 30, 2017 December 31, 2016 (In thousands) Inventory Crude oil inventory $ 7,846 $ 7,086 Equipment and materials 10,096 3,562 Total inventory $ 17,942 $ 10,648 Long-term inventory Linefill in third-party pipelines $ 8,762 $ — Long-term inventory $ 8,762 $ — Total $ 26,704 $ 10,648

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Hierarchy of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables set forth by level, within the fair value hierarchy, the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis: Fair value at June 30, 2017 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 142 $ — $ — $ 142 Commodity derivative instruments (see Note 5) — 43,685 — 43,685 Total assets $ 142 $ 43,685 $ — $ 43,827 Fair value at December 31, 2016 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 141 $ — $ — $ 141 Commodity derivative instruments (see Note 5) — 362 — 362 Total assets $ 141 $ 362 $ — $ 503 Liabilities: Commodity derivative instruments (see Note 5) $ — $ 72,183 $ — $ 72,183 Total liabilities $ — $ 72,183 $ — $ 72,183

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Outstanding Commodity Derivative Instruments	At June 30, 2017 , the Company had the following outstanding commodity derivative instruments: Commodity Settlement Derivative Volumes Weighted Average Prices Fair Value Swap Sub-Floor Floor Ceiling (In thousands) Crude oil 2017 Swaps 3,843,000 Bbl $ 49.83 $ 13,211 Crude oil 2017 Two-way collar 1,464,000 Bbl $ 46.25 $ 54.37 3,122 Crude oil 2017 Three-way collar 1,098,000 Bbl $ 31.67 $ 45.83 $ 59.94 1,816 Crude oil 2018 Swaps 5,508,000 Bbl $ 51.95 20,746 Crude oil 2018 Two-way collar 582,000 Bbl $ 48.40 $ 55.13 1,799 Crude oil 2018 Three-way collar 186,000 Bbl $ 31.67 $ 45.83 $ 59.94 452 Crude oil 2019 Swaps 434,000 Bbl $ 52.16 1,365 Crude oil 2019 Two-way collar 31,000 Bbl $ 50.00 $ 55.70 104 Natural gas 2017 Swaps 3,680,000 MMBtu $ 3.32 827 Natural gas 2018 Swaps 5,475,000 MMBtu $ 3.04 243 $ 43,685
Gains and Losses from Commodity Derivative Instruments	The following table summarizes the location and amounts of gains and losses from the Company’s commodity derivative instruments recorded in the Company’s Condensed Consolidated Statements of Operations for the periods presented: Three Months Ended June 30, Six Months Ended June 30, Statement of Operations Location 2017 2016 2017 2016 (In thousands) Net gain (loss) on derivative instruments $ 50,532 $ (90,846 ) $ 106,607 $ (76,471 )
Summary of Gross and Net Information about Commodity Derivative Assets	The following table summarizes the location and fair value of all outstanding commodity derivative instruments recorded in the Company’s Condensed Consolidated Balance Sheets: June 30, 2017 Commodity Balance Sheet Location Gross Recognized Assets Gross Amount Offset Net Recognized Fair Value Assets (In thousands) Derivatives assets: Commodity contracts Derivative instruments — current assets $ 37,829 $ (5,978 ) $ 31,851 Commodity contracts Derivative instruments — non-current assets 12,482 (648 ) 11,834 Total derivatives assets $ 50,311 $ (6,626 ) $ 43,685 December 31, 2016 Commodity Balance Sheet Location Gross Recognized Asset/Liabilities Gross Amount Offset Net Recognized Fair Value Asset/Liabilities (In thousands) Derivatives assets: Commodity contracts Derivative instruments — current assets $ 482 $ (120 ) $ 362 Total derivatives assets $ 482 $ (120 ) $ 362 Derivatives liabilities: Commodity contracts Derivative instruments — current liabilities $ 66,838 $ (6,369 ) $ 60,469 Commodity contracts Derivative instruments — non-current liabilities 14,164 (2,450 ) 11,714 Total derivatives liabilities $ 81,002 $ (8,819 ) $ 72,183
Summary of Gross and Net Information about Commodity Derivative Liabilities	The following table summarizes the location and fair value of all outstanding commodity derivative instruments recorded in the Company’s Condensed Consolidated Balance Sheets: June 30, 2017 Commodity Balance Sheet Location Gross Recognized Assets Gross Amount Offset Net Recognized Fair Value Assets (In thousands) Derivatives assets: Commodity contracts Derivative instruments — current assets $ 37,829 $ (5,978 ) $ 31,851 Commodity contracts Derivative instruments — non-current assets 12,482 (648 ) 11,834 Total derivatives assets $ 50,311 $ (6,626 ) $ 43,685 December 31, 2016 Commodity Balance Sheet Location Gross Recognized Asset/Liabilities Gross Amount Offset Net Recognized Fair Value Asset/Liabilities (In thousands) Derivatives assets: Commodity contracts Derivative instruments — current assets $ 482 $ (120 ) $ 362 Total derivatives assets $ 482 $ (120 ) $ 362 Derivatives liabilities: Commodity contracts Derivative instruments — current liabilities $ 66,838 $ (6,369 ) $ 60,469 Commodity contracts Derivative instruments — non-current liabilities 14,164 (2,450 ) 11,714 Total derivatives liabilities $ 81,002 $ (8,819 ) $ 72,183

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Jun. 30, 2017
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	The following table sets forth the Company’s property, plant and equipment: June 30, 2017 December 31, 2016 (In thousands) Proved oil and gas properties (1) $ 6,671,833 $ 6,476,833 Less: accumulated depreciation, depletion, amortization and impairment (2,130,330 ) (1,886,732 ) Proved oil and gas properties, net 4,541,503 4,590,101 Unproved oil and gas properties 816,242 819,735 Other property and equipment 695,592 618,790 Less: accumulated depreciation (122,323 ) (109,059 ) Other property and equipment, net 573,269 509,731 Total property, plant and equipment, net $ 5,931,014 $ 5,919,567 __________________ (1) Included in the Company’s proved oil and gas properties are estimates of future asset retirement costs of $43.3 million and $42.9 million at June 30, 2017 and December 31, 2016 , respectively.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	The Company’s long-term debt consists of the following: June 30, 2017 December 31, 2016 (In thousands) Senior secured revolving line of credit $ 418,000 $ 363,000 Senior unsecured notes 7.25% senior unsecured notes due February 1, 2019 54,275 54,275 6.5% senior unsecured notes due November 1, 2021 395,501 395,501 6.875% senior unsecured notes due March 15, 2022 937,080 937,080 6.875% senior unsecured notes due January 15, 2023 366,094 366,094 2.625% senior unsecured convertible notes due September 15, 2023 300,000 300,000 Total principal of senior unsecured notes 2,052,950 2,052,950 Less: unamortized deferred financing costs on senior unsecured notes (25,634 ) (28,268 ) Less: unamortized debt discount on senior unsecured convertible notes (85,633 ) (90,468 ) Total long-term debt $ 2,359,683 $ 2,297,214

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2017
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Changes in Asset Retirement Obligations	The following table reflects the changes in the Company’s ARO during the six months ended June 30, 2017 : (In thousands) Balance at December 31, 2016 $ 49,687 Liabilities incurred during period 661 Liabilities settled during period (101 ) Accretion expense during period (1) 1,316 Revisions to estimates (214 ) Balance at June 30, 2017 $ 51,349 ___________________ (1) Included in depreciation, depletion and amortization on the Company’s Condensed Consolidated Statements of Operations.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Based Compensation Assumptions	The following assumptions were used for the Monte Carlo model to determine the grant date fair value and associated stock-based compensation expense of the PSUs granted during the six months ended June 30, 2017 : Risk-free interest rate 1.18% - 1.66% Oasis volatility 17.16 %

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Schedule of Weighted-Average Number of Shares Outstanding	The following is a calculation of the basic and diluted weighted average shares outstanding for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (In thousands) Basic weighted average common shares outstanding 233,283 176,984 233,176 169,953 Dilutive effect of restricted stock awards and PSUs (1) 1,634 — 3,105 — Diluted weighted average common shares outstanding 234,917 176,984 236,281 169,953 __________________ (1) No unvested stock awards were included in computing loss per share for the three and six months ended June 30, 2016 because the effect was anti-dilutive.
Schedule of Common Shares Excluded From Diluted Earnings (Loss) per Share Calculation	The following is a calculation of weighted average common shares excluded from diluted earnings (loss) per share due to the anti-dilutive effect: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (In thousands) Restricted stock awards and PSUs 4,369 4,920 2,957 4,794

Business Segment Information (T

Business Segment Information (Tables)	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Summarized Financial Information of Segments	The following table summarizes financial information for the Company’s three business segments for the periods presented: Exploration and Production Midstream Services Well Services Eliminations Consolidated (In thousands) Three months ended June 30, 2017: Revenues from non-affiliates $ 226,724 $ 15,566 $ 11,801 $ — $ 254,091 Inter-segment revenues — 24,746 21,650 (46,396 ) — Total revenues 226,724 40,312 33,451 (46,396 ) 254,091 Operating income (loss) (17,425 ) 23,103 1,950 (2,249 ) 5,379 Other income 13,525 3 — — 13,528 Income (loss) before income taxes $ (3,900 ) $ 23,106 $ 1,950 $ (2,249 ) $ 18,907 Three months ended June 30, 2016: Revenues from non-affiliates $ 159,337 $ 6,910 $ 12,833 $ — $ 179,080 Inter-segment revenues — 22,025 8,302 (30,327 ) — Total revenues 159,337 28,935 21,135 (30,327 ) 179,080 Operating income (loss) (44,748 ) 18,056 (2,173 ) 651 (28,214 ) Other income (expense) (114,230 ) (16 ) 31 — (114,215 ) Income (loss) before income taxes $ (158,978 ) $ 18,040 $ (2,142 ) $ 651 $ (142,429 ) Six months ended June 30, 2017: Revenues from non-affiliates $ 491,607 $ 30,172 $ 17,428 $ — $ 539,207 Inter-segment revenues — 47,781 37,003 (84,784 ) — Total revenues 491,607 77,953 54,431 (84,784 ) 539,207 Operating income (loss) (16,456 ) 43,865 (1,641 ) (297 ) 25,471 Other income 33,292 2 4 — 33,298 Income (loss) before income taxes $ 16,836 $ 43,867 $ (1,637 ) $ (297 ) $ 58,769 Six months ended June 30, 2016: Revenues from non-affiliates $ 276,652 $ 13,893 $ 18,818 $ — $ 309,363 Inter-segment revenues — 44,860 33,205 (78,065 ) — Total revenues 276,652 58,753 52,023 (78,065 ) 309,363 Operating income (loss) (133,625 ) 33,200 1,848 (4,852 ) (103,429 ) Other income (expense) (131,119 ) (2 ) 37 — (131,084 ) Income (loss) before income taxes $ (264,744 ) $ 33,198 $ 1,885 $ (4,852 ) $ (234,513 ) At June 30, 2017: Property, plant and equipment, net $ 5,567,347 $ 495,112 $ 41,228 $ (172,673 ) $ 5,931,014 Total assets (1) 5,881,351 504,119 48,924 (172,673 ) 6,261,721 At December 31, 2016: Property, plant and equipment, net $ 5,620,558 $ 424,197 $ 47,189 $ (172,377 ) $ 5,919,567 Total assets (1) 5,868,747 431,095 51,167 (172,377 ) 6,178,632 ___________________ (1) Intercompany receivables (payables) for all segments were reclassified to capital contributions from (distributions to) parent and not included in total assets.

Condensed Consolidating Finan32

Condensed Consolidating Financial Information (Tables)	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet June 30, 2017 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 178 $ 11,262 $ — $ 11,440 Accounts receivable, net — 218,302 — 218,302 Accounts receivable - affiliates 187,496 33,709 (221,205 ) — Inventory — 17,942 — 17,942 Prepaid expenses 664 9,946 — 10,610 Derivative instruments — 31,851 — 31,851 Other current assets 3 59 — 62 Total current assets 188,341 323,071 (221,205 ) 290,207 Property, plant and equipment Oil and gas properties (successful efforts method) — 7,488,075 — 7,488,075 Other property and equipment — 695,592 — 695,592 Less: accumulated depreciation, depletion, amortization and impairment — (2,252,653 ) — (2,252,653 ) Total property, plant and equipment, net — 5,931,014 — 5,931,014 Investments in and advances to subsidiaries 4,545,805 — (4,545,805 ) — Derivative instruments — 11,834 — 11,834 Deferred income taxes 257,652 — (257,652 ) — Long-term inventory — 8,762 — 8,762 Other assets — 19,904 — 19,904 Total assets $ 4,991,798 $ 6,294,585 $ (5,024,662 ) $ 6,261,721 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities Accounts payable $ — $ 12,257 $ — $ 12,257 Accounts payable - affiliates 33,709 187,496 (221,205 ) — Revenues and production taxes payable — 143,715 — 143,715 Accrued liabilities — 139,766 — 139,766 Accrued interest payable 38,796 332 — 39,128 Advances from joint interest partners — 5,816 — 5,816 Total current liabilities 72,505 489,382 (221,205 ) 340,682 Long-term debt 1,941,683 418,000 — 2,359,683 Deferred income taxes — 784,833 (257,652 ) 527,181 Asset retirement obligations — 51,059 — 51,059 Other liabilities — 5,506 — 5,506 Total liabilities 2,014,188 1,748,780 (478,857 ) 3,284,111 Stockholders’ equity Capital contributions from affiliates — 3,395,528 (3,395,528 ) — Common stock, $0.01 par value: 450,000,000 shares authorized; 238,642,598 shares issued and 237,410,395 shares outstanding 2,345 — — 2,345 Treasury stock, at cost: 1,232,203 shares (21,401 ) — — (21,401 ) Additional paid-in-capital 2,362,084 8,743 (8,743 ) 2,362,084 Retained earnings 634,582 1,141,534 (1,141,534 ) 634,582 Total stockholders’ equity 2,977,610 4,545,805 (4,545,805 ) 2,977,610 Total liabilities and stockholders’ equity $ 4,991,798 $ 6,294,585 $ (5,024,662 ) $ 6,261,721 Condensed Consolidating Balance Sheet December 31, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 166 $ 11,060 $ — $ 11,226 Accounts receivable, net — 204,335 — 204,335 Accounts receivable - affiliates 252,000 27,619 (279,619 ) — Inventory — 10,648 — 10,648 Prepaid expenses 275 7,348 — 7,623 Derivative instruments — 362 — 362 Other current assets — 4,355 — 4,355 Total current assets 252,441 265,727 (279,619 ) 238,549 Property, plant and equipment Oil and gas properties (successful efforts method) — 7,296,568 — 7,296,568 Other property and equipment — 618,790 — 618,790 Less: accumulated depreciation, depletion, amortization and impairment — (1,995,791 ) — (1,995,791 ) Total property, plant and equipment, net — 5,919,567 — 5,919,567 Investments in and advances to subsidiaries 4,451,192 — (4,451,192 ) — Derivative instruments — — — — Deferred income taxes 220,058 — (220,058 ) — Other assets — 20,516 — 20,516 Total assets $ 4,923,691 $ 6,205,810 $ (4,950,869 ) $ 6,178,632 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities Accounts payable $ — $ 4,645 $ — $ 4,645 Accounts payable - affiliates 27,619 252,000 (279,619 ) — Revenues and production taxes payable — 139,737 — 139,737 Accrued liabilities 12 119,161 — 119,173 Accrued interest payable 38,689 315 — 39,004 Derivative instruments — 60,469 — 60,469 Advances from joint interest partners — 7,597 — 7,597 Other current liabilities — 10,490 — 10,490 Total current liabilities 66,320 594,414 (279,619 ) 381,115 Long-term debt 1,934,214 363,000 — 2,297,214 Deferred income taxes — 733,587 (220,058 ) 513,529 Asset retirement obligations — 48,985 — 48,985 Derivative instruments — 11,714 — 11,714 Other liabilities — 2,918 — 2,918 Total liabilities 2,000,534 1,754,618 (499,677 ) 3,255,475 Stockholders’ equity Capital contributions from affiliates — 3,388,893 (3,388,893 ) — Common stock, $0.01 par value: 450,000,000 shares authorized; 237,201,064 shares issued and 236,344,172 shares outstanding 2,331 — — 2,331 Treasury stock, at cost: 856,892 shares (15,950 ) — — (15,950 ) Additional paid-in-capital 2,345,271 8,743 (8,743 ) 2,345,271 Retained earnings 591,505 1,053,556 (1,053,556 ) 591,505 Total stockholders’ equity 2,923,157 4,451,192 (4,451,192 ) 2,923,157 Total liabilities and stockholders’ equity $ 4,923,691 $ 6,205,810 $ (4,950,869 ) $ 6,178,632
Condensed Consolidating Statement of Operations	Condensed Consolidating Statement of Operations Three Months Ended June 30, 2017 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 218,633 $ — $ 218,633 Bulk oil sales — 8,091 — 8,091 Midstream revenues — 15,566 — 15,566 Well services revenues — 11,801 — 11,801 Total revenues — 254,091 — 254,091 Operating expenses Lease operating expenses — 44,665 — 44,665 Midstream operating expenses — 3,263 — 3,263 Well services operating expenses — 8,088 — 8,088 Marketing, transportation and gathering expenses — 12,039 — 12,039 Bulk oil purchases — 7,980 — 7,980 Production taxes — 18,971 — 18,971 Depreciation, depletion and amortization — 125,291 — 125,291 Exploration expenses — 1,667 — 1,667 Impairment — 3,200 — 3,200 General and administrative expenses 7,534 16,014 — 23,548 Total operating expenses 7,534 241,178 — 248,712 Operating income (loss) (7,534 ) 12,913 — 5,379 Other income (expense) Equity in earnings of subsidiaries 38,875 — (38,875 ) — Net gain on derivative instruments — 50,532 — 50,532 Interest expense, net of capitalized interest (33,006 ) (3,832 ) — (36,838 ) Other expense — (166 ) — (166 ) Total other income 5,869 46,534 (38,875 ) 13,528 Income (loss) before income taxes (1,665 ) 59,447 (38,875 ) 18,907 Income tax benefit (expense) 18,233 (20,572 ) — (2,339 ) Net income $ 16,568 $ 38,875 $ (38,875 ) $ 16,568 Condensed Consolidating Statement of Operations Three Months Ended June 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 159,337 $ — $ 159,337 Midstream revenues — 6,910 — 6,910 Well services revenues — 12,833 — 12,833 Total revenues — 179,080 — 179,080 Operating expenses Lease operating expenses — 31,523 — 31,523 Midstream operating expenses — 1,740 — 1,740 Well services operating expenses — 7,135 — 7,135 Marketing, transportation and gathering expenses — 6,491 — 6,491 Production taxes — 14,367 — 14,367 Depreciation, depletion and amortization — 122,488 — 122,488 Exploration expenses — 340 — 340 Impairment — 23 — 23 General and administrative expenses 6,395 15,481 — 21,876 Total operating expenses 6,395 199,588 — 205,983 Loss on sale of properties — (1,311 ) — (1,311 ) Operating loss (6,395 ) (21,819 ) — (28,214 ) Other income (expense) Equity in loss of subsidiaries (71,987 ) — 71,987 — Net loss on derivative instruments — (90,846 ) — (90,846 ) Interest expense, net of capitalized interest (33,190 ) (1,789 ) — (34,979 ) Gain on extinguishment of debt 11,642 — — 11,642 Other expense — (32 ) — (32 ) Total other expense (93,535 ) (92,667 ) 71,987 (114,215 ) Loss before income taxes (99,930 ) (114,486 ) 71,987 (142,429 ) Income tax benefit 9,999 42,499 — 52,498 Net loss $ (89,931 ) $ (71,987 ) $ 71,987 $ (89,931 ) Condensed Consolidating Statement of Operations Six Months Ended June 30, 2017 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 455,885 $ — $ 455,885 Bulk oil sales — 35,722 — 35,722 Midstream revenues — 30,172 — 30,172 Well services revenues — 17,428 — 17,428 Total revenues — 539,207 — 539,207 Operating expenses Lease operating expenses — 88,537 — 88,537 Midstream operating expenses — 6,590 — 6,590 Well services operating expenses — 11,990 — 11,990 Marketing, transportation and gathering expenses — 22,990 — 22,990 Bulk oil purchases — 35,982 — 35,982 Production taxes — 39,270 — 39,270 Depreciation, depletion and amortization — 251,957 — 251,957 Exploration expenses — 3,156 — 3,156 Impairment — 5,882 — 5,882 General and administrative expenses 14,599 32,783 — 47,382 Total operating expenses 14,599 499,137 — 513,736 Operating income (loss) (14,599 ) 40,070 — 25,471 Other income (expense) Equity in earnings of subsidiaries 87,978 — (87,978 ) — Net gain on derivative instruments — 106,607 — 106,607 Interest expense, net of capitalized interest (65,857 ) (7,302 ) — (73,159 ) Other expense — (150 ) — (150 ) Total other income 22,121 99,155 (87,978 ) 33,298 Income before income taxes 7,522 139,225 (87,978 ) 58,769 Income tax benefit (expense) 32,871 (51,247 ) — (18,376 ) Net income $ 40,393 $ 87,978 $ (87,978 ) $ 40,393 Condensed Consolidating Statement of Operations Six Months Ended June 30, 2016 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 276,652 $ — $ 276,652 Midstream revenues — 13,893 — 13,893 Well services revenues — 18,818 — 18,818 Total revenues — 309,363 — 309,363 Operating expenses Lease operating expenses — 62,587 — 62,587 Midstream operating expenses — 3,478 — 3,478 Well services operating expenses — 9,786 — 9,786 Marketing, transportation and gathering expenses — 15,043 — 15,043 Production taxes — 25,120 — 25,120 Depreciation, depletion and amortization — 244,937 — 244,937 Exploration expenses — 703 — 703 Impairment — 3,585 — 3,585 General and administrative expenses 13,846 32,396 — 46,242 Total operating expenses 13,846 397,635 — 411,481 Loss on sale of properties — (1,311 ) — (1,311 ) Operating loss (13,846 ) (89,583 ) — (103,429 ) Other income (expense) Equity in loss of subsidiaries (109,314 ) — 109,314 — Net loss on derivative instruments — (76,471 ) — (76,471 ) Interest expense, net of capitalized interest (68,022 ) (5,696 ) — (73,718 ) Gain on extinguishment of debt 18,658 — — 18,658 Other income 43 404 — 447 Total other expense (158,635 ) (81,763 ) 109,314 (131,084 ) Loss before income taxes (172,481 ) (171,346 ) 109,314 (234,513 ) Income tax benefit 18,095 62,032 — 80,127 Net loss $ (154,386 ) $ (109,314 ) $ 109,314 $ (154,386 )
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows Six Months Ended June 30, 2017 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net income $ 40,393 $ 87,978 $ (87,978 ) $ 40,393 Adjustments to reconcile net income to net cash provided by operating activities: Equity in earnings of subsidiaries (87,978 ) — 87,978 — Depreciation, depletion and amortization — 251,957 — 251,957 Impairment — 5,882 — 5,882 Deferred income taxes (32,871 ) 51,247 — 18,376 Derivative instruments — (106,607 ) — (106,607 ) Stock-based compensation expenses 13,395 428 — 13,823 Deferred financing costs amortization and other 7,470 1,401 — 8,871 Working capital and other changes: Change in accounts receivable 64,504 (19,833 ) (58,414 ) (13,743 ) Change in inventory — (1,007 ) — (1,007 ) Change in prepaid expenses (389 ) 125 — (264 ) Change in other current assets (3 ) 283 — 280 Change in long-term inventory and other assets — (8,768 ) — (8,768 ) Change in accounts payable, interest payable and accrued liabilities 6,185 (53,441 ) 58,414 11,158 Change in other current liabilities — (10,490 ) — (10,490 ) Net cash provided by operating activities 10,706 199,155 — 209,861 Cash flows from investing activities: Capital expenditures — (252,461 ) — (252,461 ) Proceeds from sale of properties — 4,000 — 4,000 Derivative settlements — (8,899 ) — (8,899 ) Advances from joint interest partners — (1,781 ) — (1,781 ) Net cash used in investing activities — (259,141 ) — (259,141 ) Cash flows from financing activities: Proceeds from revolving credit facility — 484,000 — 484,000 Principal payments on revolving credit facility — (429,000 ) — (429,000 ) Purchases of treasury stock (5,451 ) — — (5,451 ) Investment in / capital contributions from subsidiaries (5,188 ) 5,188 — — Other (55 ) — — (55 ) Net cash provided by (used in) financing activities (10,694 ) 60,188 — 49,494 Increase in cash and cash equivalents 12 202 — 214 Cash and cash equivalents at beginning of period 166 11,060 — 11,226 Cash and cash equivalents at end of period $ 178 $ 11,262 $ — $ 11,440 Condensed Consolidating Statement of Cash Flows Six Months Ended June 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net loss $ (154,386 ) $ (109,314 ) $ 109,314 $ (154,386 ) Adjustments to reconcile net loss to net cash provided by (used in) operating activities: Equity in loss of subsidiaries 109,314 — (109,314 ) — Depreciation, depletion and amortization — 244,937 — 244,937 Gain on extinguishment of debt (18,658 ) — — (18,658 ) Loss on sale of properties — 1,311 — 1,311 Impairment — 3,585 — 3,585 Deferred income taxes (18,095 ) (62,032 ) — (80,127 ) Derivative instruments — 76,471 — 76,471 Stock-based compensation expenses 12,624 355 — 12,979 Deferred financing costs amortization and other 3,360 3,192 — 6,552 Working capital and other changes: Change in accounts receivable (85 ) 53,068 (48,686 ) 4,297 Change in inventory — 2,054 — 2,054 Change in prepaid expenses 278 1,145 — 1,423 Change in other current assets — (114 ) — (114 ) Change in long-term inventory and other assets 100 — — 100 Change in accounts payable, interest payable and accrued liabilities (50,462 ) (16,258 ) 48,686 (18,034 ) Change in other current liabilities — 9,001 — 9,001 Change in other liabilities — 10 — 10 Net cash provided by (used in) operating activities (116,010 ) 207,411 — 91,401 Cash flows from investing activities: Capital expenditures — (231,341 ) — (231,341 ) Proceeds from sale of properties — 11,679 — 11,679 Costs related to sale of properties — (310 ) — (310 ) Derivative settlements — 103,790 — 103,790 Advances from joint interest partners — 769 — 769 Net cash used in investing activities — (115,413 ) — (115,413 ) Cash flows from financing activities: Proceeds from revolving credit facility — 359,000 — 359,000 Principal payments on revolving credit facility — (462,000 ) — (462,000 ) Repurchase of senior unsecured notes (56,925 ) — — (56,925 ) Deferred financing costs — (751 ) — (751 ) Proceeds from sale of common stock 182,953 — — 182,953 Purchases of treasury stock (1,520 ) — — (1,520 ) Investment in / capital contributions from subsidiaries (9,190 ) 9,190 — — Net cash provided by (used in) financing activities 115,318 (94,561 ) — 20,757 Decrease in cash and cash equivalents (692 ) (2,563 ) — (3,255 ) Cash and cash equivalents at beginning of period 777 8,953 — 9,730 Cash and cash equivalents at end of period $ 85 $ 6,390 $ — $ 6,475

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment for adoption of ASU 2016-09		$ 4,724
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment for adoption of ASU 2016-09		$ 2,684
Retained Earnings [Member] | Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment for adoption of ASU 2016-09	$ 2,700

Inventory- Schedule of Inventor

Inventory- Schedule of Inventory (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Inventory
Crude oil inventory	$ 7,846	$ 7,086
Equipment and materials	10,096	3,562
Total inventory	17,942	10,648
Long-term inventory
Linefill in third-party pipelines	8,762	0
Long-term inventory	8,762	0
Total	$ 26,704	$ 10,648

Fair Value Measurements - Hiera

Fair Value Measurements - Hierarchy of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets:
Total assets	$ 43,827	$ 503
Liabilities:
Total liabilities		72,183
Money market funds [Member]
Assets:
Total assets	142	141
Commodity derivative instruments [Member]
Assets:
Total assets	43,685	362
Liabilities:
Total liabilities		72,183
Level 1 [Member]
Assets:
Total assets	142	141
Liabilities:
Total liabilities		0
Level 1 [Member] | Money market funds [Member]
Assets:
Total assets	142	141
Level 1 [Member] | Commodity derivative instruments [Member]
Assets:
Total assets	0	0
Liabilities:
Total liabilities		0
Level 2 [Member]
Assets:
Total assets	43,685	362
Liabilities:
Total liabilities		72,183
Level 2 [Member] | Money market funds [Member]
Assets:
Total assets	0	0
Level 2 [Member] | Commodity derivative instruments [Member]
Assets:
Total assets	43,685	362
Liabilities:
Total liabilities		72,183
Level 3 [Member]
Assets:
Total assets	0	0
Liabilities:
Total liabilities		0
Level 3 [Member] | Money market funds [Member]
Assets:
Total assets	0	0
Level 3 [Member] | Commodity derivative instruments [Member]
Assets:
Total assets	$ 0	0
Liabilities:
Total liabilities		$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Derivative credit risk valuation adjustment, derivative assets	$ (41)
Derivative credit risk valuation adjustment, derivative liabilities		$ 2,000

Derivative Instruments - Schedu

Derivative Instruments - Schedule of Outstanding Commodity Derivative Instruments (Details) bbl in Thousands, MMBTU in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)MMBTU$ / bbl$ / MMBTUbbl
Derivative [Line Items]
Fair value asset | $	$ 43,685
Oil [Member] | 2017 Swaps [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	3,843
Average swap price (in dollars per barrel)	49.83
Fair value asset | $	$ 13,211
Oil [Member] | 2017 Two Way Collars [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	1,464
Average floor price (in dollars per barrel)	46.25
Average ceiling price (in dollars per barrel)	54.37
Fair value asset | $	$ 3,122
Oil [Member] | 2017 Three Way Collars [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	1,098
Average sub-floor price (in dollars per barrel)	31.67
Average floor price (in dollars per barrel)	45.83
Average ceiling price (in dollars per barrel)	59.94
Fair value asset | $	$ 1,816
Oil [Member] | 2018 Swaps [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	5,508
Average swap price (in dollars per barrel)	51.95
Fair value asset | $	$ 20,746
Oil [Member] | 2018 Two Way Collars [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	582
Average floor price (in dollars per barrel)	48.40
Average ceiling price (in dollars per barrel)	55.13
Fair value asset | $	$ 1,799
Oil [Member] | 2018 Three Way Collars [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	186
Average sub-floor price (in dollars per barrel)	31.67
Average floor price (in dollars per barrel)	45.83
Average ceiling price (in dollars per barrel)	59.94
Fair value asset | $	$ 452
Oil [Member] | 2019 Swaps [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	434
Average swap price (in dollars per barrel)	52.16
Fair value asset | $	$ 1,365
Oil [Member] | 2019 Two-way Collars [Member]
Derivative [Line Items]
Total ntional amount of oil (in Bbls) | bbl	31
Average floor price (in dollars per barrel)	50
Average ceiling price (in dollars per barrel)	55.70
Fair value asset | $	$ 104
Natural Gas [Member] | 2017 Swaps [Member]
Derivative [Line Items]
Total notional amount of natural gas (in MMBtu) | MMBTU	3,680
Average swap price (in dollars per barrel) | $ / MMBTU	3.32
Fair value asset | $	$ 827
Natural Gas [Member] | 2018 Swaps [Member]
Derivative [Line Items]
Total notional amount of natural gas (in MMBtu) | MMBTU	5,475
Average swap price (in dollars per barrel) | $ / MMBTU	3.04
Fair value asset | $	$ 243

Derivative Instruments - Realiz

Derivative Instruments - Realized and Unrealized Gains and Losses from Commodity Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net gain (loss) on derivative instruments	$ 50,532	$ (90,846)	$ 106,607	$ (76,471)

Derivative Instruments - Sche39

Derivative Instruments - Schedule of Location and Fair Value of Outstanding Commodity Derivative Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative asset, gross amounts recognized	$ 50,311	$ 482
Derivative liability, gross amount recognized		81,002
Derivative asset, gross amounts offset	(6,626)	(120)
Derivative liability, gross amounts offset		(8,819)
Derivative asset, net asset	43,685	362
Derivative liability, net liability		72,183
Commodity derivative instruments [Member] | Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross amounts recognized	37,829	482
Derivative asset, gross amounts offset	(5,978)	(120)
Derivative asset, net asset	31,851	362
Commodity derivative instruments [Member] | Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross amounts recognized	12,482
Derivative asset, gross amounts offset	(648)
Derivative asset, net asset	$ 11,834
Commodity derivative instruments [Member] | Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized		66,838
Derivative liability, gross amounts offset		(6,369)
Derivative liability, net liability		60,469
Commodity derivative instruments [Member] | Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized		14,164
Derivative liability, gross amounts offset		(2,450)
Derivative liability, net liability		$ 11,714

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Proved oil and gas properties	$ 6,671,833	$ 6,476,833
Less: accumulated depreciation, depletion, amortization and impairment	(2,130,330)	(1,886,732)
Proved oil and gas properties, net	4,541,503	4,590,101
Unproved oil and gas properties	816,242	819,735
Other property and equipment	695,592	618,790
Less: accumulated depreciation	(122,323)	(109,059)
Other property and equipment, net	573,269	509,731
Total property, plant and equipment, net	$ 5,931,014	$ 5,919,567

Property, Plant and Equipment P

Property, Plant and Equipment Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Thousands	Apr. 25, 2017	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Estimate of future asset retirement costs		$ 43,300		$ 42,900
Notes payable from acquisition		$ 4,875	$ 0
the Purchase Agreement [Member]
Business Acquisition [Line Items]
Total consideration in the purchase and sale agreement	$ 12,700
Installment notes payable	4,900
Estimated fair value of assets purchased	$ 12,700

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Debt Instrument [Line Items]
Total long-term debt	$ 2,359,683	$ 2,297,214
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total principal of senior unsecured notes and revolving line of credit	418,000	363,000
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Total principal of senior unsecured notes and revolving line of credit	2,052,950	2,052,950
Less: unamortized deferred financing costs on senior unsecured notes	$ (25,634)	(28,268)
Senior Unsecured Debt [Member] | 7.25% senior unsecured notes due February 1, 2019 [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)	7.25%
Total principal of senior unsecured notes and revolving line of credit	$ 54,275	54,275
Senior Unsecured Debt [Member] | 6.5% senior unsecured notes due November 1, 2021 [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)	6.50%
Total principal of senior unsecured notes and revolving line of credit	$ 395,501	395,501
Senior Unsecured Debt [Member] | 6.875% senior unsecured notes due March 15, 2022 [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)	6.875%
Total principal of senior unsecured notes and revolving line of credit	$ 937,080	937,080
Senior Unsecured Debt [Member] | 6.875% senior unsecured notes due January 15, 2023 [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)	6.875%
Total principal of senior unsecured notes and revolving line of credit	$ 366,094	366,094
Senior Unsecured Debt [Member] | 2.625% senior convertible notes due September 15, 2023 [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)	2.625%		2.625%
Total principal of senior unsecured notes and revolving line of credit	$ 300,000	300,000
Less: unamortized debt discount on senior unsecured convertible notes	$ (85,633)	$ (90,468)	$ (93,200)

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details)	1 Months Ended	6 Months Ended
	Sep. 30, 2016USD ($)day$ / shares	Jun. 30, 2017USD ($)	Apr. 10, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Total long-term debt		$ 2,359,683,000			$ 2,297,214,000
Ownership percentage, guarantors (as percent)		100.00%
Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt, fair value		$ 1,994,800,000
Line of Credit [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding		10,000,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt, gross		418,000,000			363,000,000
Line of credit facility amount		2,500,000,000
Credit facility borrowing base			$ 1,600,000,000	$ 1,150,000,000
Line of credit facility, current borrowing capacity		$ 1,150,000,000
Weighted average interest rate (as percent)		3.00%
Line of credit facility, remaining borrowing capacity		$ 722,000,000
Commitment fee percentage		0.375%
Line of Credit [Member] | Revolving Credit Facility [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding		$ 418,000,000
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuance costs		25,634,000			28,268,000
Long-term debt, gross		2,052,950,000			2,052,950,000
Senior Unsecured Debt [Member] | Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Total long-term debt		2,053,000,000
Senior Unsecured Debt [Member] | Notes [Member]
Debt Instrument [Line Items]
Unsecured debt		$ 1,753,000,000
Senior Unsecured Debt [Member] | Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)		6.50%
Senior Unsecured Debt [Member] | Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)		7.25%
Senior Unsecured Debt [Member] | 7.25% senior unsecured notes due February 1, 2019 [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 54,275,000			54,275,000
Stated interest rate (as percent)		7.25%
Number of days required for unsecured noted to be retired or refinanced prior to maturity		90 days
Senior Unsecured Debt [Member] | 6.5% senior unsecured notes due November 1, 2021 [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 395,501,000			395,501,000
Stated interest rate (as percent)		6.50%
Senior Unsecured Debt [Member] | 6.875% senior unsecured notes due March 15, 2022 [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 937,080,000			937,080,000
Stated interest rate (as percent)		6.875%
Senior Unsecured Debt [Member] | 2.625% senior convertible notes due September 15, 2023 [Member]
Debt Instrument [Line Items]
Debt discount	$ 93,200,000	$ 85,633,000			90,468,000
Long-term debt, gross		$ 300,000,000			$ 300,000,000
Stated interest rate (as percent)	2.625%	2.625%
Debt issued	$ 300,000,000
Debt conversion rate per $1000 principal (in shares per $1000)	0.0763650
Debt conversion price (in dollars per share) | $ / shares	$ 13.10
Debt instrument effective interest rate (percent)	8.97%
Estimated fair value of debt	$ 206,800,000
Debt Conversion Scenario 1 [Member] | Senior Unsecured Debt [Member] | 2.625% senior convertible notes due September 15, 2023 [Member]
Debt Instrument [Line Items]
Number of trading days | day	20
Number of consecutive trading days | day	30
Stock price relative to conversion price (percent)	130.00%
Debt Conversion Scenario 2 [Member] | Senior Unsecured Debt [Member] | 2.625% senior convertible notes due September 15, 2023 [Member]
Debt Instrument [Line Items]
Number of trading days | day	5
Number of consecutive trading days | day	5
Stock price relative to product of sale price and conversion rate (percent)	98.00%

Asset Retirement Obligations -

Asset Retirement Obligations - Schedule of Changes in Asset Retirement Obligations (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at December 31, 2016	$ 49,687
Liabilities incurred during period	661
Liabilities settled during period	(101)
Accretion expense during period	1,316
Revisions to estimates	(214)
Balance at June 30, 2017	$ 51,349

Asset Retirement Obligations 45

Asset Retirement Obligations - Additional Information (Details) $ in Millions	Jun. 30, 2017USD ($)
Asset Retirement Obligation Disclosure [Abstract]
Total asset retirement obligations, current portion	$ 0.3

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Effective tax rate (as percent)	(12.40%)	36.90%	(31.30%)	34.20%

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)shares	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)day$ / sharesshares	Jun. 30, 2016USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expenses | $			$ 13,823	$ 12,979
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Stock granted (in shares) | shares			1,588,010
Granted, weighted average grant date fair value per unit (in usd per share) | $ / shares			$ 15.24
Stock-based compensation expenses | $	$ 4,900	$ 4,900	$ 10,300	10,700
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock granted (in shares) | shares			509,800
Granted, weighted average grant date fair value per unit (in usd per share) | $ / shares			$ 16.89
Stock-based compensation expenses | $	$ 2,200	$ 1,300	$ 3,500	$ 2,200
Right to received shares of common stock (in shares) | shares	1		1
Number of trading days | day			30
Volatility assumption, volume weighted average stock price			30 days
Performance Share Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSU granted percentage of earnings (as a percent)			0.00%
Performance Share Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSU granted percentage of earnings (as a percent)			200.00%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Assumptions (Details) - Performance Share Units [Member]	6 Months Ended
	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Oasis stock price volatility (as percent)	17.16%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate (as percent)	1.18%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate (as percent)	1.66%

Earnings (Loss) Per Share - Sch

Earnings (Loss) Per Share - Schedule of Weighted-Average Number of Shares Outstanding (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Basic weighted average common shares outstanding (in shares)	233,283	176,984	233,176	169,953
Diluted weighted average common shares outstanding (in shares)	234,917	176,984	236,281	169,953
Stock Awards and PSUs [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Dilution effect of stock awards at end of period (in shares)	1,634	0	3,105	0

Earnings (Loss) Per Share - S50

Earnings (Loss) Per Share - Schedule of Common Shares Excluded from Diluted Earnings (Loss) per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Anti-dilutive stock-based compensation awards (in shares)	4,369	4,920	2,957	4,794

Business Segment Information -

Business Segment Information - Additional Information (Details)	6 Months Ended
	Jun. 30, 2017Segment
Segment Reporting [Abstract]
Number of current operating units	3

Business Segment Information 52

Business Segment Information - Summarized Financial Information of Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total revenues	$ 254,091	$ 179,080	$ 539,207	$ 309,363
Operating income (loss)	5,379	(28,214)	25,471	(103,429)
Other income (expense)	13,528	(114,215)	33,298	(131,084)
Income (loss) before income taxes	18,907	(142,429)	58,769	(234,513)
Property, plant and equipment, net	5,931,014		5,931,014		$ 5,919,567
Total assets	6,261,721		6,261,721		6,178,632
Exploration and Production [Member]
Segment Reporting Information [Line Items]
Total revenues	226,724	159,337	491,607	276,652
Midstream Services [Member]
Segment Reporting Information [Line Items]
Total revenues	40,312	28,935	77,953	58,753
Well Services [Member]
Segment Reporting Information [Line Items]
Total revenues	33,451	21,135	54,431	52,023
Operating Segments [Member] | Exploration and Production [Member]
Segment Reporting Information [Line Items]
Total revenues	226,724	159,337	491,607	276,652
Operating income (loss)	(17,425)	(44,748)	(16,456)	(133,625)
Other income (expense)	13,525	(114,230)	33,292	(131,119)
Income (loss) before income taxes	(3,900)	(158,978)	16,836	(264,744)
Property, plant and equipment, net	5,567,347		5,567,347		5,620,558
Total assets	5,881,351		5,881,351		5,868,747
Operating Segments [Member] | Midstream Services [Member]
Segment Reporting Information [Line Items]
Total revenues	15,566	6,910	30,172	13,893
Operating income (loss)	23,103	18,056	43,865	33,200
Other income (expense)	3	(16)	2	(2)
Income (loss) before income taxes	23,106	18,040	43,867	33,198
Property, plant and equipment, net	495,112		495,112		424,197
Total assets	504,119		504,119		431,095
Operating Segments [Member] | Well Services [Member]
Segment Reporting Information [Line Items]
Total revenues	11,801	12,833	17,428	18,818
Operating income (loss)	1,950	(2,173)	(1,641)	1,848
Other income (expense)	0	31	4	37
Income (loss) before income taxes	1,950	(2,142)	(1,637)	1,885
Property, plant and equipment, net	41,228		41,228		47,189
Total assets	48,924		48,924		51,167
Segment Reconciling Items [Member] | Exploration and Production [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Segment Reconciling Items [Member] | Midstream Services [Member]
Segment Reporting Information [Line Items]
Total revenues	24,746	22,025	47,781	44,860
Segment Reconciling Items [Member] | Well Services [Member]
Segment Reporting Information [Line Items]
Total revenues	21,650	8,302	37,003	33,205
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	(46,396)	(30,327)	(84,784)	(78,065)
Operating income (loss)	(2,249)	651	(297)	(4,852)
Other income (expense)	0	0	0	0
Income (loss) before income taxes	(2,249)	$ 651	(297)	$ (4,852)
Property, plant and equipment, net	(172,673)		(172,673)		(172,377)
Total assets	$ (172,673)		$ (172,673)		$ (172,377)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	Mar. 23, 2017USD ($)
Mirada Litigation [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Damages sought (in excess of)	$ 100

Condensed Consolidating Finan54

Condensed Consolidating Financial Information - Additional Information (Details)	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Ownership percentage, guarantors (as percent)	100.00%

Condensed Consolidating Finan55

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 11,440	$ 11,226	$ 6,475	$ 9,730
Accounts receivable, net	218,302	204,335
Accounts receivable - affiliates	0	0
Inventory	17,942	10,648
Prepaid expenses	10,610	7,623
Derivative instruments	31,851	362
Other current assets	62	4,355
Total current assets	290,207	238,549
Property, plant and equipment
Oil and gas properties (successful efforts method)	7,488,075	7,296,568
Other property and equipment	695,592	618,790
Less: accumulated depreciation, depletion, amortization and impairment	(2,252,653)	(1,995,791)
Total property, plant and equipment, net	5,931,014	5,919,567
Investments in and advances to subsidiaries	0	0
Derivative instruments	11,834	0
Deferred income taxes	0	0
Long-term inventory	8,762	0
Other assets	19,904	20,516
Total assets	6,261,721	6,178,632
Current liabilities
Accounts payable	12,257	4,645
Accounts payable - affiliates	0	0
Revenues and production taxes payable	143,715	139,737
Accrued liabilities	139,766	119,173
Accrued interest payable	39,128	39,004
Derivative instruments	0	60,469
Advances from joint interest partners	5,816	7,597
Other current liabilities	0	10,490
Total current liabilities	340,682	381,115
Long-term debt	2,359,683	2,297,214
Deferred income taxes	527,181	513,529
Asset retirement obligations	51,059	48,985
Derivative instruments	0	11,714
Other liabilities	5,506	2,918
Total liabilities	3,284,111	3,255,475
Stockholders’ equity
Capital contributions from affiliates	0	0
Common stock, $0.01 par value: 450,000,000 shares authorized; 238,642,598 shares issued and 237,410,395 shares outstanding at June 30, 2017 and 237,201,064 shares issued and 236,344,172 shares outstanding at December 31, 2016	2,345	2,331
Treasury stock, at cost: 1,232,203 and 856,892 shares at June 30, 2017 and December 31, 2016, respectively	(21,401)	(15,950)
Additional paid-in capital	2,362,084	2,345,271
Retained earnings	634,582	591,505
Total stockholders’ equity	2,977,610	2,923,157
Total liabilities and stockholders’ equity	6,261,721	6,178,632
Intercompany Eliminations [Member]
Current assets
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Accounts receivable - affiliates	(221,205)	(279,619)
Inventory	0	0
Prepaid expenses	0	0
Derivative instruments	0	0
Other current assets	0	0
Total current assets	(221,205)	(279,619)
Property, plant and equipment
Oil and gas properties (successful efforts method)	0	0
Other property and equipment	0	0
Less: accumulated depreciation, depletion, amortization and impairment	0	0
Total property, plant and equipment, net	0	0
Investments in and advances to subsidiaries	(4,545,805)	(4,451,192)
Derivative instruments	0	0
Deferred income taxes	(257,652)	(220,058)
Long-term inventory	0
Other assets	0	0
Total assets	(5,024,662)	(4,950,869)
Current liabilities
Accounts payable	0	0
Accounts payable - affiliates	(221,205)	(279,619)
Revenues and production taxes payable	0	0
Accrued liabilities	0	0
Accrued interest payable	0	0
Derivative instruments		0
Advances from joint interest partners	0	0
Other current liabilities		0
Total current liabilities	(221,205)	(279,619)
Long-term debt	0	0
Deferred income taxes	(257,652)	(220,058)
Asset retirement obligations	0	0
Derivative instruments		0
Other liabilities	0	0
Total liabilities	(478,857)	(499,677)
Stockholders’ equity
Capital contributions from affiliates	(3,395,528)	(3,388,893)
Common stock, $0.01 par value: 450,000,000 shares authorized; 238,642,598 shares issued and 237,410,395 shares outstanding at June 30, 2017 and 237,201,064 shares issued and 236,344,172 shares outstanding at December 31, 2016	0	0
Treasury stock, at cost: 1,232,203 and 856,892 shares at June 30, 2017 and December 31, 2016, respectively	0	0
Additional paid-in capital	(8,743)	(8,743)
Retained earnings	(1,141,534)	(1,053,556)
Total stockholders’ equity	(4,545,805)	(4,451,192)
Total liabilities and stockholders’ equity	(5,024,662)	(4,950,869)
Parent/Issuer [Member]
Current assets
Cash and cash equivalents	178	166	85	777
Accounts receivable, net	0	0
Accounts receivable - affiliates	187,496	252,000
Inventory	0	0
Prepaid expenses	664	275
Derivative instruments	0	0
Other current assets	3	0
Total current assets	188,341	252,441
Property, plant and equipment
Oil and gas properties (successful efforts method)	0	0
Other property and equipment	0	0
Less: accumulated depreciation, depletion, amortization and impairment	0	0
Total property, plant and equipment, net	0	0
Investments in and advances to subsidiaries	4,545,805	4,451,192
Derivative instruments	0	0
Deferred income taxes	257,652	220,058
Long-term inventory	0
Other assets	0	0
Total assets	4,991,798	4,923,691
Current liabilities
Accounts payable	0	0
Accounts payable - affiliates	33,709	27,619
Revenues and production taxes payable	0	0
Accrued liabilities	0	12
Accrued interest payable	38,796	38,689
Derivative instruments		0
Advances from joint interest partners	0	0
Other current liabilities		0
Total current liabilities	72,505	66,320
Long-term debt	1,941,683	1,934,214
Deferred income taxes	0	0
Asset retirement obligations	0	0
Derivative instruments		0
Other liabilities	0	0
Total liabilities	2,014,188	2,000,534
Stockholders’ equity
Capital contributions from affiliates	0	0
Common stock, $0.01 par value: 450,000,000 shares authorized; 238,642,598 shares issued and 237,410,395 shares outstanding at June 30, 2017 and 237,201,064 shares issued and 236,344,172 shares outstanding at December 31, 2016	2,345	2,331
Treasury stock, at cost: 1,232,203 and 856,892 shares at June 30, 2017 and December 31, 2016, respectively	(21,401)	(15,950)
Additional paid-in capital	2,362,084	2,345,271
Retained earnings	634,582	591,505
Total stockholders’ equity	2,977,610	2,923,157
Total liabilities and stockholders’ equity	4,991,798	4,923,691
Combined Guarantor Subsidiaries [Member]
Current assets
Cash and cash equivalents	11,262	11,060	$ 6,390	$ 8,953
Accounts receivable, net	218,302	204,335
Accounts receivable - affiliates	33,709	27,619
Inventory	17,942	10,648
Prepaid expenses	9,946	7,348
Derivative instruments	31,851	362
Other current assets	59	4,355
Total current assets	323,071	265,727
Property, plant and equipment
Oil and gas properties (successful efforts method)	7,488,075	7,296,568
Other property and equipment	695,592	618,790
Less: accumulated depreciation, depletion, amortization and impairment	(2,252,653)	(1,995,791)
Total property, plant and equipment, net	5,931,014	5,919,567
Investments in and advances to subsidiaries	0	0
Derivative instruments	11,834	0
Deferred income taxes	0	0
Long-term inventory	8,762
Other assets	19,904	20,516
Total assets	6,294,585	6,205,810
Current liabilities
Accounts payable	12,257	4,645
Accounts payable - affiliates	187,496	252,000
Revenues and production taxes payable	143,715	139,737
Accrued liabilities	139,766	119,161
Accrued interest payable	332	315
Derivative instruments		60,469
Advances from joint interest partners	5,816	7,597
Other current liabilities		10,490
Total current liabilities	489,382	594,414
Long-term debt	418,000	363,000
Deferred income taxes	784,833	733,587
Asset retirement obligations	51,059	48,985
Derivative instruments		11,714
Other liabilities	5,506	2,918
Total liabilities	1,748,780	1,754,618
Stockholders’ equity
Capital contributions from affiliates	3,395,528	3,388,893
Common stock, $0.01 par value: 450,000,000 shares authorized; 238,642,598 shares issued and 237,410,395 shares outstanding at June 30, 2017 and 237,201,064 shares issued and 236,344,172 shares outstanding at December 31, 2016	0	0
Treasury stock, at cost: 1,232,203 and 856,892 shares at June 30, 2017 and December 31, 2016, respectively	0	0
Additional paid-in capital	8,743	8,743
Retained earnings	1,141,534	1,053,556
Total stockholders’ equity	4,545,805	4,451,192
Total liabilities and stockholders’ equity	$ 6,294,585	$ 6,205,810

Condensed Consolidating Finan56

Condensed Consolidating Financial Information Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Balance Sheet - Additional Information (Details) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	450,000,000	450,000,000
Common stock, shares issued (in shares)	238,642,598	237,201,064
Common stock, shares outstanding (in shares)	237,410,395	236,344,172
Treasury stock, shares (in shares)	1,232,203	856,892

Condensed Consolidating Finan57

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues
Oil and gas revenues	$ 218,633	$ 159,337	$ 455,885	$ 276,652
Bulk oil sales	8,091	0	35,722	0
Midstream revenues	15,566	6,910	30,172	13,893
Well services revenues	11,801	12,833	17,428	18,818
Total revenues	254,091	179,080	539,207	309,363
Operating expenses
Lease operating expenses	44,665	31,523	88,537	62,587
Midstream operating expenses	3,263	1,740	6,590	3,478
Well services operating expenses	8,088	7,135	11,990	9,786
Marketing, transportation and gathering expenses	12,039	6,491	22,990	15,043
Bulk oil purchases	7,980	0	35,982	0
Production taxes	18,971	14,367	39,270	25,120
Depreciation, depletion and amortization	125,291	122,488	251,957	244,937
Exploration expenses	1,667	340	3,156	703
Impairment	3,200	23	5,882	3,585
General and administrative expenses	23,548	21,876	47,382	46,242
Total operating expenses	248,712	205,983	513,736	411,481
Loss on sale of properties	0	(1,311)	0	(1,311)
Operating income (loss)	5,379	(28,214)	25,471	(103,429)
Other income (expense)
Equity in earnings of subsidiaries	0	0	0	0
Net gain (loss) on derivative instruments	50,532	(90,846)	106,607	(76,471)
Interest expense, net of capitalized interest	(36,838)	(34,979)	(73,159)	(73,718)
Gain on extinguishment of debt	0	11,642	0	18,658
Other expense	(166)	(32)	(150)	447
Total other income (expense)	13,528	(114,215)	33,298	(131,084)
Income (loss) before income taxes	18,907	(142,429)	58,769	(234,513)
Income tax benefit	(2,339)	52,498	(18,376)	80,127
Net income (loss)	16,568	(89,931)	40,393	(154,386)
Intercompany Eliminations [Member]
Revenues
Oil and gas revenues	0	0	0	0
Bulk oil sales	0		0
Midstream revenues	0	0	0	0
Well services revenues	0	0	0	0
Total revenues	0	0	0	0
Operating expenses
Lease operating expenses	0	0	0	0
Midstream operating expenses	0	0	0	0
Well services operating expenses	0	0	0	0
Marketing, transportation and gathering expenses	0	0	0	0
Bulk oil purchases	0		0
Production taxes	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Exploration expenses	0	0	0	0
Impairment	0	0	0	0
General and administrative expenses	0	0	0	0
Total operating expenses	0	0	0	0
Loss on sale of properties		0		0
Operating income (loss)	0	0	0	0
Other income (expense)
Equity in earnings of subsidiaries	(38,875)	71,987	(87,978)	109,314
Net gain (loss) on derivative instruments	0	0	0	0
Interest expense, net of capitalized interest	0	0	0	0
Gain on extinguishment of debt		0		0
Other expense	0	0	0	0
Total other income (expense)	(38,875)	71,987	(87,978)	109,314
Income (loss) before income taxes	(38,875)	71,987	(87,978)	109,314
Income tax benefit	0	0	0	0
Net income (loss)	(38,875)	71,987	(87,978)	109,314
Parent/Issuer [Member]
Revenues
Oil and gas revenues	0	0	0	0
Bulk oil sales	0		0
Midstream revenues	0	0	0	0
Well services revenues	0	0	0	0
Total revenues	0	0	0	0
Operating expenses
Lease operating expenses	0	0	0	0
Midstream operating expenses	0	0	0	0
Well services operating expenses	0	0	0	0
Marketing, transportation and gathering expenses	0	0	0	0
Bulk oil purchases	0		0
Production taxes	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Exploration expenses	0	0	0	0
Impairment	0	0	0	0
General and administrative expenses	7,534	6,395	14,599	13,846
Total operating expenses	7,534	6,395	14,599	13,846
Loss on sale of properties		0		0
Operating income (loss)	(7,534)	(6,395)	(14,599)	(13,846)
Other income (expense)
Equity in earnings of subsidiaries	38,875	(71,987)	87,978	(109,314)
Net gain (loss) on derivative instruments	0	0	0	0
Interest expense, net of capitalized interest	(33,006)	(33,190)	(65,857)	(68,022)
Gain on extinguishment of debt		11,642		18,658
Other expense	0	0	0	43
Total other income (expense)	5,869	(93,535)	22,121	(158,635)
Income (loss) before income taxes	(1,665)	(99,930)	7,522	(172,481)
Income tax benefit	18,233	9,999	32,871	18,095
Net income (loss)	16,568	(89,931)	40,393	(154,386)
Combined Guarantor Subsidiaries [Member]
Revenues
Oil and gas revenues	218,633	159,337	455,885	276,652
Bulk oil sales	8,091		35,722
Midstream revenues	15,566	6,910	30,172	13,893
Well services revenues	11,801	12,833	17,428	18,818
Total revenues	254,091	179,080	539,207	309,363
Operating expenses
Lease operating expenses	44,665	31,523	88,537	62,587
Midstream operating expenses	3,263	1,740	6,590	3,478
Well services operating expenses	8,088	7,135	11,990	9,786
Marketing, transportation and gathering expenses	12,039	6,491	22,990	15,043
Bulk oil purchases	7,980		35,982
Production taxes	18,971	14,367	39,270	25,120
Depreciation, depletion and amortization	125,291	122,488	251,957	244,937
Exploration expenses	1,667	340	3,156	703
Impairment	3,200	23	5,882	3,585
General and administrative expenses	16,014	15,481	32,783	32,396
Total operating expenses	241,178	199,588	499,137	397,635
Loss on sale of properties		(1,311)		(1,311)
Operating income (loss)	12,913	(21,819)	40,070	(89,583)
Other income (expense)
Equity in earnings of subsidiaries	0	0	0	0
Net gain (loss) on derivative instruments	50,532	(90,846)	106,607	(76,471)
Interest expense, net of capitalized interest	(3,832)	(1,789)	(7,302)	(5,696)
Gain on extinguishment of debt		0		0
Other expense	(166)	(32)	(150)	404
Total other income (expense)	46,534	(92,667)	99,155	(81,763)
Income (loss) before income taxes	59,447	(114,486)	139,225	(171,346)
Income tax benefit	(20,572)	42,499	(51,247)	62,032
Net income (loss)	$ 38,875	$ (71,987)	$ 87,978	$ (109,314)

Condensed Consolidating Finan58

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ 16,568	$ (89,931)	$ 40,393	$ (154,386)
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries	0	0	0	0
Depreciation, depletion and amortization	125,291	122,488	251,957	244,937
Loss on extinguishment of debt	0	(11,642)	0	(18,658)
Loss on sale of properties			0	1,311
Impairment	3,200	23	5,882	3,585
Deferred income taxes			18,376	(80,127)
Derivative instruments	(50,532)	90,846	(106,607)	76,471
Stock-based compensation expenses			13,823	12,979
Deferred financing costs amortization and other			8,871	6,552
Working capital and other changes:
Change in accounts receivable			(13,743)	4,297
Change in inventory			(1,007)	2,054
Change in prepaid expenses			(264)	1,423
Change in other current assets			280	(114)
Change in long-term inventory and other assets			(8,768)	100
Change in accounts payable, interest payable and accrued liabilities			11,158	(18,034)
Change in other current liabilities			(10,490)	9,001
Change in other liabilities			0	10
Net cash provided by operating activities			209,861	91,401
Cash flows from investing activities:
Capital expenditures			(252,461)	(231,341)
Proceeds from sale of properties			4,000	11,679
Costs related to sale of properties			0	(310)
Derivative settlements			(8,899)	103,790
Advances from joint interest partners			(1,781)	769
Net cash used in investing activities			(259,141)	(115,413)
Cash flows from financing activities:
Proceeds from revolving credit facility			484,000	359,000
Principal payments on revolving credit facility			(429,000)	(462,000)
Repurchase of senior unsecured notes			0	(56,925)
Deferred financing costs			0	(751)
Proceeds from sale of common stock			0	182,953
Purchases of treasury stock			(5,451)	(1,520)
Investment in / capital contributions from subsidiaries			0	0
Other			(55)	0
Net cash provided by financing activities			49,494	20,757
Increase (decrease) in cash and cash equivalents			214	(3,255)
Beginning of period			11,226	9,730
End of period	11,440	6,475	11,440	6,475
Intercompany Eliminations [Member]
Cash flows from operating activities:
Net income (loss)	(38,875)	71,987	(87,978)	109,314
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries	38,875	(71,987)	87,978	(109,314)
Depreciation, depletion and amortization	0	0	0	0
Loss on extinguishment of debt		0		0
Loss on sale of properties				0
Impairment	0	0	0	0
Deferred income taxes			0	0
Derivative instruments	0	0	0	0
Stock-based compensation expenses			0	0
Deferred financing costs amortization and other			0	0
Working capital and other changes:
Change in accounts receivable			(58,414)	(48,686)
Change in inventory			0	0
Change in prepaid expenses			0	0
Change in other current assets			0	0
Change in long-term inventory and other assets			0	0
Change in accounts payable, interest payable and accrued liabilities			58,414	48,686
Change in other current liabilities			0	0
Change in other liabilities				0
Net cash provided by operating activities			0	0
Cash flows from investing activities:
Capital expenditures			0	0
Proceeds from sale of properties			0	0
Costs related to sale of properties				0
Derivative settlements			0	0
Advances from joint interest partners			0	0
Net cash used in investing activities			0	0
Cash flows from financing activities:
Proceeds from revolving credit facility			0	0
Principal payments on revolving credit facility			0	0
Repurchase of senior unsecured notes				0
Deferred financing costs				0
Proceeds from sale of common stock				0
Purchases of treasury stock			0	0
Investment in / capital contributions from subsidiaries			0	0
Other			0
Net cash provided by financing activities			0	0
Increase (decrease) in cash and cash equivalents			0	0
Beginning of period			0	0
End of period	0	0	0	0
Parent/Issuer [Member]
Cash flows from operating activities:
Net income (loss)	16,568	(89,931)	40,393	(154,386)
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries	(38,875)	71,987	(87,978)	109,314
Depreciation, depletion and amortization	0	0	0	0
Loss on extinguishment of debt		(11,642)		(18,658)
Loss on sale of properties				0
Impairment	0	0	0	0
Deferred income taxes			(32,871)	(18,095)
Derivative instruments	0	0	0	0
Stock-based compensation expenses			13,395	12,624
Deferred financing costs amortization and other			7,470	3,360
Working capital and other changes:
Change in accounts receivable			64,504	(85)
Change in inventory			0	0
Change in prepaid expenses			(389)	278
Change in other current assets			(3)	0
Change in long-term inventory and other assets			0	100
Change in accounts payable, interest payable and accrued liabilities			6,185	(50,462)
Change in other current liabilities			0	0
Change in other liabilities				0
Net cash provided by operating activities			10,706	(116,010)
Cash flows from investing activities:
Capital expenditures			0	0
Proceeds from sale of properties			0	0
Costs related to sale of properties				0
Derivative settlements			0	0
Advances from joint interest partners			0	0
Net cash used in investing activities			0	0
Cash flows from financing activities:
Proceeds from revolving credit facility			0	0
Principal payments on revolving credit facility			0	0
Repurchase of senior unsecured notes				(56,925)
Deferred financing costs				0
Proceeds from sale of common stock				182,953
Purchases of treasury stock			(5,451)	(1,520)
Investment in / capital contributions from subsidiaries			(5,188)	(9,190)
Other			(55)
Net cash provided by financing activities			(10,694)	115,318
Increase (decrease) in cash and cash equivalents			12	(692)
Beginning of period			166	777
End of period	178	85	178	85
Combined Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net income (loss)	38,875	(71,987)	87,978	(109,314)
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of subsidiaries	0	0	0	0
Depreciation, depletion and amortization	125,291	122,488	251,957	244,937
Loss on extinguishment of debt		0		0
Loss on sale of properties				1,311
Impairment	3,200	23	5,882	3,585
Deferred income taxes			51,247	(62,032)
Derivative instruments	(50,532)	90,846	(106,607)	76,471
Stock-based compensation expenses			428	355
Deferred financing costs amortization and other			1,401	3,192
Working capital and other changes:
Change in accounts receivable			(19,833)	53,068
Change in inventory			(1,007)	2,054
Change in prepaid expenses			125	1,145
Change in other current assets			283	(114)
Change in long-term inventory and other assets			(8,768)	0
Change in accounts payable, interest payable and accrued liabilities			(53,441)	(16,258)
Change in other current liabilities			(10,490)	9,001
Change in other liabilities				10
Net cash provided by operating activities			199,155	207,411
Cash flows from investing activities:
Capital expenditures			(252,461)	(231,341)
Proceeds from sale of properties			4,000	11,679
Costs related to sale of properties				(310)
Derivative settlements			(8,899)	103,790
Advances from joint interest partners			(1,781)	769
Net cash used in investing activities			(259,141)	(115,413)
Cash flows from financing activities:
Proceeds from revolving credit facility			484,000	359,000
Principal payments on revolving credit facility			(429,000)	(462,000)
Repurchase of senior unsecured notes				0
Deferred financing costs				(751)
Proceeds from sale of common stock				0
Purchases of treasury stock			0	0
Investment in / capital contributions from subsidiaries			5,188	9,190
Other			0
Net cash provided by financing activities			60,188	(94,561)
Increase (decrease) in cash and cash equivalents			202	(2,563)
Beginning of period			11,060	8,953
End of period	$ 11,262	$ 6,390	$ 11,262	$ 6,390

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] - Crude Oil [Member] bbl in Thousands	1 Months Ended
	Jul. 31, 2017$ / bblbbl
2017 Swaps and Two-way Collar Options [Member]
Subsequent Event [Line Items]
Total ntional amount of oil (in Bbls) | bbl	244
Weighted average floor price (in dollars per barrel) | $ / bbl	49.43
2018 Swaps and Two-way Collar Options [Member]
Subsequent Event [Line Items]
Total ntional amount of oil (in Bbls) | bbl	2,915
Weighted average floor price (in dollars per barrel) | $ / bbl	48.59
2019 Swaps and Two-way Collar Options [Member]
Subsequent Event [Line Items]
Total ntional amount of oil (in Bbls) | bbl	248
Weighted average floor price (in dollars per barrel) | $ / bbl	48.49