Chord Energy (CHRD) 10-Q 8 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 02, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
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		236,365,219

Condensed Consolidated Balance

Condensed Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Cash and cash equivalents	$ 13,776	$ 9,730
Accounts receivable — oil and gas revenues	103,128	96,495
Accounts receivable — joint interest and other	77,903	100,914
Inventory	8,513	11,072
Prepaid expenses	6,093	7,328
Derivative instruments	9,142	139,697
Other current assets	4,290	50
Total current assets	222,845	365,286
Property, plant and equipment
Oil and gas properties (successful efforts method)	6,438,782	6,284,401
Other property and equipment	580,171	443,265
Less: accumulated depreciation, depletion, amortization and impairment	(1,866,280)	(1,509,424)
Total property, plant and equipment, net	5,152,673	5,218,242
Assets held for sale	0	26,728
Derivative instruments	194	15,776
Other assets	22,549	23,343
Total assets	5,398,261	5,649,375
Current liabilities
Accounts payable	7,929	9,983
Revenues and production taxes payable	141,991	132,356
Accrued liabilities	98,926	167,669
Accrued interest payable	19,798	49,413
Derivative instruments	17,308	0
Advances from joint interest partners	5,191	4,647
Other current liabilities		6,500
Total current liabilities	291,143	370,568
Long-term debt	2,125,573	2,302,584
Deferred income taxes	546,202	608,155
Asset retirement obligations	37,092	35,338
Liabilities held for sale	0	10,228
Derivative instruments	7,755	0
Other liabilities	2,992	3,160
Total liabilities	3,010,757	3,330,033
Commitments and contingencies
Stockholders’ equity
Common stock, $0.01 par value: 450,000,000 and 300,000,000 shares authorized at September 30, 2016 and December 31, 2015, respectively; 182,038,164 shares issued and 181,186,070 shares outstanding at September 30, 2016 and 139,583,990 shares issued and 139,076,064 shares outstanding at December 31, 2015	1,779	1,376
Treasury stock, at cost: 852,094 and 507,926 shares at September 30, 2016 and December 31, 2015, respectively	(15,895)	(13,620)
Additional paid-in capital	1,755,427	1,497,065
Retained earnings	646,193	834,521
Total stockholders’ equity	2,387,504	2,319,342
Total liabilities and stockholders’ equity	$ 5,398,261	$ 5,649,375

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheet (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
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	300,000,000
Common stock, shares issued (in shares)	182,038,164	139,583,990
Common stock, shares outstanding (in shares)	181,186,070	139,076,064
Treasury stock, shares (in shares)	852,094	507,926

Condensed Consolidated Statemen

Condensed Consolidated Statement of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues
Oil and gas revenues	$ 158,183	$ 175,270	$ 434,835	$ 563,239
Well services and midstream revenues	19,128	21,965	51,839	44,429
Total revenues	177,311	197,235	486,674	607,668
Operating expenses
Lease operating expenses	35,696	35,670	98,283	112,556
Well services and midstream operating expenses	8,165	10,023	21,429	19,370
Marketing, transportation and gathering expenses	8,856	8,465	23,899	23,313
Production taxes	14,638	16,676	39,758	53,915
Depreciation, depletion and amortization	111,948	123,734	356,885	361,430
Exploration expenses	489	327	1,192	2,252
Rig termination	0	0	0	3,895
Impairment	382	80	3,967	24,917
General and administrative expenses	22,845	22,358	69,087	67,190
Total operating expenses	203,019	217,333	614,500	668,838
Gain (loss) on sale of properties	6	172	(1,305)	172
Operating loss	(25,702)	(19,926)	(129,131)	(60,998)
Other income (expense)
Net gain (loss) on derivative instruments	20,847	103,637	(55,624)	111,285
Interest expense, net of capitalized interest	(31,726)	(36,513)	(105,444)	(112,702)
Gain (loss) on extinguishment of debt	(13,793)	0	4,865	0
Other income (expense)	(259)	249	188	370
Total other income (expense)	(24,931)	67,373	(156,015)	(1,047)
Income (loss) before income taxes	(50,633)	47,447	(285,146)	(62,045)
Income tax benefit (expense)	16,691	(20,392)	96,818	17,829
Net income (loss)	$ (33,942)	$ 27,055	$ (188,328)	$ (44,216)
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.19)	$ 0.20	$ (1.09)	$ (0.35)
Diluted (in dollars per share)	$ (0.19)	$ 0.20	$ (1.09)	$ (0.35)
Weighted average shares outstanding:
Basic (in shares)	177,120	137,014	172,360	127,827
Diluted (in shares)	177,120	137,014	172,360	127,827

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - 9 months ended Sep. 30, 2016 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in-Capital [Member]	Retained Earnings [Member]
Balance, shares at Dec. 31, 2015		139,076	508
Balance at Dec. 31, 2015	$ 2,319,342	$ 1,376	$ (13,620)	$ 1,497,065	$ 834,521
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, shares		39,100
Issuance of common stock	182,791	$ 391		182,400
Stock-based compensation, shares		3,354
Stock-based compensation	20,109			20,109
Vesting of restricted shares	0	$ 12		(12)
Equity component of senior unsecured convertible notes, net	55,865			55,865
Treasury stock - tax withholdings, shares		(344)	(344)
Treasury stock – tax withholdings	(2,275)		$ (2,275)
Net loss	(188,328)				(188,328)
Balance, shares at Sep. 30, 2016		181,186	852
Balance at Sep. 30, 2016	$ 2,387,504	$ 1,779	$ (15,895)	$ 1,755,427	$ 646,193

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net loss	$ (188,328)	$ (44,216)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	356,885	361,430
Gain on extinguishment of debt	(4,865)	0
(Gain) loss on sale of properties	1,305	(172)
Impairment	3,967	24,917
Deferred income taxes	(96,818)	(17,829)
Derivative instruments	55,624	(111,285)
Stock-based compensation expenses	18,761	19,629
Deferred financing costs amortization and other	10,174	7,468
Working capital and other changes:
Change in accounts receivable	11,349	108,309
Change in inventory	2,559	8,425
Change in prepaid expenses	1,168	638
Change in other current assets	(240)	5,529
Change in other assets	(148)	0
Change in accounts payable, interest payable and accrued liabilities	(41,991)	(84,133)
Change in other current liabilities	(6,000)	1,655
Change in other liabilities	17	(28)
Net cash provided by operating activities	123,419	280,337
Cash flows from investing activities:
Capital expenditures	(340,314)	(740,633)
Proceeds from sale of properties	12,333	78
Costs related to sale of properties	(310)	0
Derivative settlements	115,576	291,436
Advances from joint interest partners	544	(1,239)
Net cash used in investing activities	(212,171)	(450,358)
Cash flows from financing activities:
Proceeds from revolving credit facility	835,000	618,000
Principal payments on revolving credit facility	(778,000)	(938,000)
Repurchase of senior unsecured notes	(435,907)	0
Proceeds from issuance of senior unsecured convertible notes	300,000	0
Deferred financing costs	(8,811)	(3,587)
Proceeds from sale of common stock	182,791	462,833
Purchases of treasury stock	(2,275)	(2,771)
Net cash provided by financing activities	92,798	136,475
Increase (decrease) in cash and cash equivalents	4,046	(33,546)
Cash and cash equivalents:
Beginning of period	9,730	45,811
End of period	13,776	12,265
Supplemental non-cash transactions:
Change in accrued capital expenditures	(49,177)	(233,913)
Change in asset retirement obligations	$ (8,083)	$ 3,405

Organization and Operations of

Organization and Operations of the Company	9 Months Ended
	Sep. 30, 2016
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 well services business through Oasis Well Services LLC (“OWS”) and a midstream services business through Oasis Midstream Services LLC (“OMS”), 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	9 Months Ended
	Sep. 30, 2016
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, 2015 is derived from audited financial statements. 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, 2015 (“ 2015 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. Oil and natural gas prices have declined significantly since mid-2014. As a result of sustained lower commodity prices, the Company decreased its 2016 capital expenditures, excluding acquisitions, as compared to 2015 and continues to concentrate its drilling activities in certain areas that are the most economic in the Williston Basin. 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 2015 Annual Report. 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. Going concern. In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 codifies in GAAP management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 is effective for the annual reporting period ending after December 15, 2016 and for annual periods and interim periods thereafter. The adoption of this guidance will not impact the Company’s financial position, cash flows or results of operations but could result in additional disclosures. Inventory. In July 2015, the FASB issued Accounting Standards Update No. 2015-11, Simplifying the Measurement of Inventory (“ASU 2015-11”). ASU 2015-11 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 is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. The Company does not expect the adoption of this guidance to have a material impact on its financial position, cash flows or 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. Embedded derivatives. In March 2016, the FASB issued Accounting Standards Update No. 2016-06, Contingent Put and Call Options in Debt Instruments (“ASU 2016-06”), which clarifies what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. ASU 2016-06 is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. The Company does not expect the adoption of this guidance to have a material impact on its financial position, cash flows or results of operations. Stock-based compensation. In March 2016, the FASB issued 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. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. The Company will record a cumulative-effect adjustment to equity at the beginning of 2017 when the guidance is adopted and does not expect the adoption of this guidance to have a material impact on its cash flows or 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 statement of cash flows.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2016
Inventory Disclosure [Abstract]
Inventory	Inventory Crude oil inventory includes oil in tank and linefill. 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. Inventory is stated at the lower of cost or market value with cost determined on an average cost method. Inventory consists of the following: September 30, 2016 December 31, 2015 (In thousands) Crude oil inventory $ 5,344 $ 6,152 Equipment and materials 3,169 4,920 Total inventory $ 8,513 $ 11,072

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
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 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 September 30, 2016 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 54 $ — $ — $ 54 Commodity derivative instruments (see Note 5) — 9,336 — 9,336 Total assets $ 54 $ 9,336 $ — $ 9,390 Liabilities: Commodity derivative instruments (see Note 5) $ — $ 25,063 $ — $ 25,063 Total liabilities $ — $ 25,063 $ — $ 25,063 Fair value at December 31, 2015 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 742 $ — $ — $ 742 Commodity derivative instruments (see Note 5) — 155,473 — 155,473 Total assets $ 742 $ 155,473 $ — $ 156,215 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 Sheet at September 30, 2016 and December 31, 2015 . 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. However, the Company does not have access to the specific proprietary valuation models or inputs used by its counterparties or third-party preparer. 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 liability by $1.2 million at September 30, 2016 and an adjustment to reduce the fair value of its net derivative asset by $0.3 million at December 31, 2015 . There were no transfers between fair value levels during the nine months ended September 30, 2016 and 2015 . Fair Value of Other Financial Instruments The Company’s financial instruments, including certain cash and cash equivalents, accounts receivable and accounts payable, are carried at cost, which approximates fair value due to the short-term maturity of these instruments. At September 30, 2016 , the Company’s cash equivalents were all Level 1 assets. The carrying amount of the Company’s long-term debt reported in the Condensed Consolidated Balance Sheet at September 30, 2016 was $2,125.6 million , which included $2,053.0 million of senior unsecured notes, reductions for the unamortized debt discount related to the equity component of the senior unsecured convertible notes and the unamortized deferred financing costs on the senior unsecured notes of $92.9 million and $29.5 million , respectively, and $195.0 million of borrowings under the revolving credit facility (see Note 8 – Long-Term Debt). The fair value of the Company’s senior unsecured notes, which are publicly traded and therefore categorized as Level 1 liabilities, was $2,018.0 million at September 30, 2016 . The Company determined the fair value of the liability component of the senior unsecured convertible notes as of their issuance dates by estimating the fair value of a similar debt instrument without the conversion feature (see Note 8 – Long-Term Debt). The significant inputs used were the market credit spread on the Company’s senior unsecured notes with similar maturity dates, the risk-free interest rate and the terms of the senior unsecured convertible notes, which are directly observable in the marketplace, representing Level 2 inputs. Non-Financial Assets and Liabilities Asset retirement obligations. The carrying amount of ARO in the Company’s Condensed Consolidated Balance Sheet at September 30, 2016 was $37.8 million (see Note 9 – Asset Retirement Obligations). The Company determines its ARO by calculating the present value of estimated cash flows related to the liability. Estimating the future ARO requires management to make estimates and judgments regarding the timing and existence of a liability, as well as what constitutes adequate restoration when considering current regulatory requirements. Inherent in the fair value calculation are numerous assumptions and judgments, including the ultimate costs, inflation factors, credit adjusted discount rates, timing of settlement and changes in the legal, regulatory, environmental and political environments. These assumptions represent Level 3 inputs. To the extent future revisions to these assumptions impact the fair value of the existing ARO liability, a corresponding adjustment is made to the related asset. Impairment. The Company reviews its proved oil and natural gas properties for impairment whenever events and circumstances indicate that a decline in the recoverability of their carrying value may have occurred. The Company estimates the expected undiscounted future cash flows of its proved oil and natural gas properties and then compares such undiscounted future cash flows to the carrying amount of the proved oil and natural gas properties to determine if the carrying amount is recoverable. If the carrying amount exceeds the estimated undiscounted future cash flows, the Company will adjust the carrying amount of the proved oil and natural gas properties to the fair value. The factors used to determine fair value are subject to management’s judgment and expertise and include, but are not limited to, recent sales prices of comparable properties, the present value of future cash flows, net of estimated operating and development costs, using estimates of proved reserves, future commodity pricing, future production estimates, anticipated capital expenditures and various discount rates commensurate with the risk and current market conditions associated with realizing the expected cash flows projected. These assumptions represent Level 3 inputs. On April 1, 2016, the Company sold certain proved oil and natural gas properties and other midstream properties (see Note 7 – Divestiture). For the nine months ended September 30, 2016 , the Company recorded an impairment charge of $3.6 million , of which $2.4 million was included in its midstream services segment and $1.2 million was included in its exploration and production segment, to adjust the current carrying value of these assets, net of the associated ARO liabilities, to their estimated fair value. For the year ended December 31, 2015, the Company recorded an impairment charge of $9.4 million to adjust its net assets held for sale to their estimated fair value in its exploration and production segment. The fair value was determined based on the expected sales price, less costs to sell. No other impairment charges on proved oil and natural gas properties were recorded for the nine months ended September 30, 2016 . No impairment charges on proved oil and natural gas properties were recorded for the three months ended September 30, 2016 and the three and nine months ended September 30, 2015 . In addition, as a result of expiring leases and periodic assessments of unproved properties, the Company recorded non-cash impairment charges on its unproved oil and natural gas properties of $0.4 million for both the three and nine months ended September 30, 2016 , respectively, and $0.1 million and $24.9 million for the three and nine months ended September 30, 2015 , respectively. The impairment charges included $0.2 million for both the three and nine months ended September 30, 2016 and $16.4 million for the nine months ended September 30, 2015 related to acreage expiring in future periods because there were no current plans to drill or extend the leases prior to their expiration. For the three months ended September 30, 2015 , the Company did not record similar impairment charges for unexpired leases.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2016
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 September 30, 2016 , 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). 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 Sheet 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 Statement 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 Statement of Cash Flows. At September 30, 2016 , 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 2016 Swaps 2,973,000 Bbl $ 49.18 $ 4,765 Crude oil 2017 Swaps 5,059,000 Bbl $ 48.04 (14,742 ) Crude oil 2017 Two-way collar 1,002,000 Bbl $ 41.67 $ 50.58 (4,092 ) Crude oil 2017 Three-way collar 1,670,000 Bbl $ 30.00 $ 45.00 $ 60.11 241 Crude oil 2018 Swaps 522,000 Bbl $ 50.07 (1,349 ) Crude oil 2018 Two-way collar 93,000 Bbl $ 41.67 $ 50.58 (471 ) Crude oil 2018 Three-way collar 155,000 Bbl $ 30.00 $ 45.00 $ 60.11 (122 ) Natural gas 2017 Swaps 1,336,000 MMbtu $ 3.12 52 Natural gas 2018 Swaps 124,000 MMbtu $ 3.12 (9 ) $ (15,727 ) The following table summarizes the location and fair value of all outstanding commodity derivative instruments recorded in the Company’s Condensed Consolidated Balance Sheet: Fair Value Asset (Liability) Type Balance Sheet Location September 30, 2016 December 31, 2015 (In thousands) Commodity contracts Derivative instruments — current assets $ 9,142 $ 139,697 Commodity contracts Derivative instruments — non-current assets 194 15,776 Commodity contracts Derivative instruments — current liabilities (17,308 ) — Commodity contracts Derivative instruments — non-current liabilities (7,755 ) — Total derivative instruments $ (15,727 ) $ 155,473 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 Statement of Operations for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, Statement of Operations Location 2016 2015 2016 2015 (In thousands) Net gain (loss) on derivative instruments $ 20,847 $ 103,637 $ (55,624 ) $ 111,285 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 Sheet. The following tables summarize gross and net information about the Company’s commodity derivative instruments: Offsetting of Derivative Assets Gross Amounts of Recognized Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet (In thousands) At September 30, 2016 $ 23,713 $ (14,377 ) $ 9,336 At December 31, 2015 155,473 — 155,473 Offsetting of Derivative Liabilities Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Balance Sheet Net Amounts of Liabilities Presented in the Balance Sheet (In thousands) At September 30, 2016 $ 39,440 $ (14,377 ) $ 25,063 At December 31, 2015 — — —

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2016
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: September 30, 2016 December 31, 2015 (In thousands) Proved oil and gas properties (1) $ 5,813,928 $ 5,655,759 Less: accumulated depreciation, depletion, amortization and impairment (1,764,979 ) (1,428,427 ) Proved oil and gas properties, net 4,048,949 4,227,332 Unproved oil and gas properties 624,854 628,642 Other property and equipment 580,171 443,265 Less: accumulated depreciation (101,301 ) (80,997 ) Other property and equipment, net 478,870 362,268 Total property, plant and equipment, net $ 5,152,673 $ 5,218,242 __________________ (1) Included in the Company’s proved oil and gas properties are estimates of future asset retirement costs of $31.5 million and $30.7 million at September 30, 2016 and December 31, 2015 , respectively.

Divestiture

Divestiture	9 Months Ended
	Sep. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Divestiture	Divestiture On April 1, 2016, the Company completed the sale of certain legacy wells that have been producing from conventional reservoirs such as the Madison, Red River and other formations in the Williston Basin other than the Bakken or Three Forks formations for cash proceeds of $12.3 million , which includes customary post close adjustments, and a $4.0 million 10% secured promissory note due within one year. These sold assets primarily consisted of oil and gas properties in the Company’s exploration and production segment and included certain other property and equipment in the Company’s midstream segment. For the three and nine months ended September 30, 2016 , customary post close adjustments were included in the loss on sale of properties on the Company’s Condensed Consolidated Statement of Operations. For the nine months ended September 30, 2016 and the year ended December 31, 2015, the Company recorded impairment charges of $3.6 million and $9.4 million , respectively, which were included in impairment on the Company’s Condensed Consolidated Statement of Operations, to adjust the carrying value of these assets to their estimated fair value, determined based on the expected sales price, less costs to sell. There were no similar charges recorded during the three months ended September 30, 2016 and three and nine months ended September 30, 2015 .

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt The Company’s long-term debt consists of the following: September 30, 2016 December 31, 2015 (In thousands) Senior secured revolving line of credit $ 195,000 $ 138,000 Senior unsecured notes 7.25% senior unsecured notes due February 1, 2019 54,275 400,000 6.5% senior unsecured notes due November 1, 2021 395,501 400,000 6.875% senior unsecured notes due March 15, 2022 937,080 1,000,000 6.875% senior unsecured notes due January 15, 2023 366,094 400,000 2.625% senior unsecured convertible notes due September 15, 2023 300,000 — Total principal of senior unsecured notes 2,052,950 2,200,000 Less: unamortized deferred financing costs on senior unsecured notes (29,500 ) (35,416 ) Less: unamortized debt discount on senior unsecured convertible notes (92,877 ) — Total long-term debt $ 2,125,573 $ 2,302,584 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 September 30, 2016 , which has a maturity date of April 13, 2020. 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 February 23, 2016, the lenders under the Credit Facility completed their regular semi-annual redetermination of the borrowing base scheduled for April 1, 2016, resulting in a decrease in the borrowing base and aggregate elected commitment from $1,525.0 million to $1,150.0 million . As of September 30, 2016 , the Company had $195.0 million of LIBOR loans and $12.3 million of outstanding letters of credit issued under the Credit Facility, resulting in an unused borrowing base committed capacity of $942.7 million . The weighted average interest rate on borrowings outstanding under the Credit Facility was 2.0% and 1.9% as of September 30, 2016 and December 31, 2015 , respectively. On a quarterly basis, the Company also pays a 0.375% (as of September 30, 2016 ) 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 September 30, 2016 . Senior unsecured notes. At September 30, 2016 , 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 7.25% senior unsecured notes due February 2019 (the “2019 Notes”) are currently redeemable for cash at a redemption price equal to 101.813% of their principal amount plus accrued and unpaid interest to the redemption date, which redemption price declines to par on February 1, 2017. The Company estimates that the fair value of these redemption options is immaterial at September 30, 2016 and December 31, 2015 . Repurchases of senior unsecured notes. On September 28, 2016, the Company completed its tender offers to repurchase certain outstanding Senior Notes (the “Tender Offers”). As a result of the Tender Offers, the Company repurchased an aggregate principal amount of $362.4 million of its outstanding Senior Notes, consisting of $344.7 million principal amount of its 2019 Notes, $2.2 million principal amount of its 6.5% senior unsecured notes due November 2021 (the “2021 Notes”), $3.4 million principal amount of its 6.875% senior unsecured notes due March 2022 (the “2022 Notes”) and $12.1 million principal amount of its 6.875% senior unsecured notes due January 2023 (the “2023 Notes”), for an aggregate cost of $371.4 million , including accrued interest and fees. In addition to the Tender Offers, the Company repurchased an aggregate principal amount of $84.6 million of its outstanding Senior Notes, consisting of $1.0 million principal amount of its 2019 Notes, $2.3 million principal amount of its 2021 Notes, $59.5 million principal amount of its 2022 Notes and $21.8 million principal amount of its 2023 Notes, for an aggregate cost of $64.5 million , including accrued interest and fees, during the nine months ended September 30, 2016 . For the three and nine months ended September 30, 2016 , the Company recognized a pre-tax loss of $13.8 million and a pre-tax gain of $4.9 million , respectively, related to these repurchases, including the Tender Offers, which were net of unamortized deferred financing costs write-offs of $5.3 million and $6.3 million , respectively, and are reflected in gain (loss) on extinguishment of debt in the Company’s Condensed Consolidated Statement of Operations. 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”), which resulted in aggregate net proceeds to the Company of $291.9 million , after deducting underwriting discounts and commissions and estimated offering expenses. The Company used the proceeds from the Senior Convertible Notes to fund the repurchase of certain outstanding Senior Notes through the Tender Offers. The Senior Convertible Notes will mature on September 15, 2023 unless earlier converted in accordance with their terms. 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 commencing after the calendar quarter ending on September 30, 2016 (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 September 30, 2016, 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. Transaction costs related to the Senior Convertible Notes issuance were allocated to the liability and equity components based on their relative fair values. Issuance costs attributable to the liability component of $5.4 million were recorded in deferred financing costs within long-term debt on the Company’s Condensed Consolidated Balance Sheet and are being amortized to interest expense over the term of the Senior Convertible Notes using the effective interest method. Issuance costs attributable to the equity component of $2.4 million were recorded as a charge to additional paid-in capital. 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. Deferred financing costs. At September 30, 2016 , the Company had $35.0 million of deferred financing costs related to the Notes and the Credit Facility. Deferred financing costs of $29.5 million related to the Notes are included in long-term debt on the Company’s Condensed Consolidated Balance Sheet at September 30, 2016 , and are being amortized over the respective terms of the Notes. Deferred financing costs of $5.5 million related to the Credit Facility are included in other assets on the Company’s Condensed Consolidated Balance Sheet at September 30, 2016 , and are being amortized over the term of the Credit Facility. Amortization of deferred financing costs recorded was $2.1 million and $6.2 million for the three and nine months ended September 30, 2016 , respectively, and $1.6 million and $5.0 million for the three and nine months ended September 30, 2015 , respectively. These costs are included in interest expense on the Company’s Condensed Consolidated Statement of Operations. For the nine months ended September 30, 2016 and 2015 , the Company’s interest expense also included $1.8 million and $0.5 million , respectively, for unamortized deferred financing costs related to the Credit Facility, which were written off in proportion to the decreases in the borrowing base. No deferred financing costs related to the Credit Facility were written off during the three months ended September 30, 2016 and 2015 . Aforementioned, the gain (loss) on extinguishment of debt in the Company’s Condensed Consolidated Statement of Operations included unamortized deferred financing costs write-offs of $5.3 million and $6.3 million related to the repurchased Notes for the three and nine months ended September 30, 2016 , respectively. No deferred financing costs related to the Notes were written off during the three and nine months ended September 30, 2015 .

Asset Retirement Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2016
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The following table reflects the changes in the Company’s ARO during the nine months ended September 30, 2016 : (In thousands) Balance at December 31, 2015 $ 35,812 Liabilities incurred during period 465 Liabilities settled during period (1) (444 ) Accretion expense during period (2) 1,425 Revisions to estimates 571 Balance at September 30, 2016 $ 37,829 ___________________ (1) Liabilities settled during the nine months ended September 30, 2016 included ARO related to the sold properties (see Note 7 – Divestiture). (2) Included in depreciation, depletion and amortization on the Company’s Condensed Consolidated Statement of Operations. At September 30, 2016 , the current portion of the total ARO balance was approximately $0.7 million and was included in accrued liabilities on the Company’s Condensed Consolidated Balance Sheet.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s effective tax rate for the three and nine months ended September 30, 2016 was 33.0% and 34.0% , respectively. The Company’s effective tax rate for the three and nine months ended September 30, 2015 was 43.0% and 28.7% , respectively. The effective tax rates for the three and nine months ended September 30, 2016 and the nine months ended September 30, 2015 were 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 these periods, while the effective tax rate for three months ended September 30, 2015 was higher 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 income for the period. The permanent differences were primarily between amounts expensed for book purposes versus the amounts deductible for income tax purposes related to stock-based compensation vesting during the three and nine months ended September 30, 2016 and 2015 . While the Company is in an overall deferred tax liability position, the Company had deferred tax assets for its federal and state tax net operating losses and other tax carryforwards recorded in deferred income taxes at September 30, 2016 . Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. During the nine months ended September 30, 2016 , the Company recorded a valuation allowance of $0.8 million and $0.6 million for Montana net operating losses and for federal charitable contribution carryovers, respectively, based on management’s assessment that it is more likely than not that these net deferred tax assets will not be realized prior to their expiration due to their short carryover periods, current economic conditions and expectations for the future. Management determined that a valuation allowance was not required for its U.S. federal tax net operating loss carryforwards as they are expected to be fully utilized before their expiration. However, the amount of deferred tax assets considered realizable could be reduced in the future if subjective positive evidence becomes limited by objective negative evidence. Management’s estimates of future taxable income are significantly affected by changes in commodity prices, the timing and amount of future production and future operating and capital costs. At September 30, 2016 , the Company did not have any uncertain tax positions requiring adjustments to its tax liability.

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Common Stock	Common Stock On February 2, 2016, the Company completed a public offering of 39,100,000 shares of its common stock (including 5,100,000 shares issued pursuant to the underwriters’ option to purchase additional common stock) at an offering price of $4.685 per share. Net proceeds from the offering were $182.8 million , after deducting underwriting discounts and commissions and offering expenses, of which $0.4 million is included in common stock and $182.4 million is included in additional paid-in capital on the Company’s Condensed Consolidated Balance Sheet at September 30, 2016 . The Company used the net proceeds for general corporate purposes. The offering was made pursuant to an effective shelf registration statement on Form S-3 filed with the SEC on July 15, 2014.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2016
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 grants 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. For the nine months ended September 30, 2016 , the Company assumed annual forfeiture rates by employee group ranging from 0% to 20.0% based on the Company’s forfeiture history for this type of award. During the nine months ended September 30, 2016 , employees and non-employee directors of the Company were granted restricted stock awards equal to 3,393,900 shares of common stock with a $5.61 weighted average grant date per share value. Stock-based compensation expense recorded for restricted stock awards for the three and nine months ended September 30, 2016 was $4.8 million and $15.5 million , respectively, and $5.0 million and $16.8 million for the three and nine months ended September 30, 2015 , respectively. Stock-based compensation expense is included in general and administrative expenses on the Company’s Condensed Consolidated Statement 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. For the nine months ended September 30, 2016 , the Company assumed annual forfeiture rates by employee group ranging from 3.3% to 4.6% based on the Company’s forfeiture history for the officer employee groups receiving PSUs. During the nine months ended September 30, 2016 , officers of the Company were granted 910,000 PSUs with a $ 3.00 weighted average grant date per share value. Stock-based compensation expense recorded for PSUs for the three and nine months ended September 30, 2016 was $1.0 million and $3.2 million , respectively, and $1.0 million and $2.9 million for the three and nine months ended September 30, 2015 , respectively. Stock-based compensation expense is included in general and administrative expenses on the Company’s Condensed Consolidated Statement 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. The grant date fair value for each grant of PSUs is recognized on a straight-line basis over a four-year total performance period. 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, which results in an expected percentage of PSUs earned. 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 rate is the U.S. Treasury bond rate on the date of grant that corresponds to the total 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 is the standard deviation of the average percentage change in stock price 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 nine months ended September 30, 2016 : Forecast period (years) 4.00 Risk-free interest rate 1.25 % Oasis stock price volatility 59.38 % For the PSUs granted during the nine months ended September 30, 2016 , the Monte Carlo simulation model resulted in approximately 69% of PSUs expected to be earned.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	9 Months Ended
	Sep. 30, 2016
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 impact of potentially dilutive non-vested restricted shares and PSUs outstanding during the periods presented, unless their effect is anti-dilutive. There are no adjustments made to the earnings (loss) attributable 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 nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (In thousands) Basic weighted average common shares outstanding 177,120 137,014 172,360 127,827 Dilution effect of stock awards at end of period — — — — Diluted weighted average common shares outstanding 177,120 137,014 172,360 127,827 During the three and nine months ended September 30, 2016 and the nine months ended September 30, 2015 , the Company incurred a net loss and therefore the diluted loss per share calculation for those periods excludes the anti-dilutive effect of 5,139,848 , 4,935,353 and 2,939,368 unvested stock awards, respectively. In addition, the diluted earnings per share calculation for the three months ended September 30, 2015 excludes the dilutive effect of 2,787,054 unvested stock awards that were anti-dilutive under the treasury stock method. 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 (see Note 8 – Long-Term Debt). 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 September 30, 2016 , 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 nine months ended September 30, 2016 .

Business Segment Information

Business Segment Information	9 Months Ended
	Sep. 30, 2016
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 well services business segment (OWS) performs 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 Company’s midstream services business segment (OMS) performs salt water gathering and disposal 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 and natural gas gathering. The revenues and expenses related to work performed by OWS and OMS 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 Statement 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, which is defined as segment operating revenues less operating expenses, including depreciation, depletion and amortization. The following table summarizes financial information for the Company’s three business segments for the periods presented: Exploration and Production Well Services Midstream Services Eliminations Consolidated (In thousands) Three months ended September 30, 2016: Revenues from non-affiliates $ 158,183 $ 10,641 $ 8,487 $ — $ 177,311 Inter-segment revenues — 11,818 20,790 (32,608 ) — Total revenues 158,183 22,459 29,277 (32,608 ) 177,311 Operating income (loss) (41,857 ) 1,572 16,525 (1,942 ) (25,702 ) Other income (expense) (24,476 ) 5 (460 ) — (24,931 ) Income (loss) before income taxes $ (66,333 ) $ 1,577 $ 16,065 $ (1,942 ) $ (50,633 ) Three months ended September 30, 2015: Revenues from non-affiliates $ 175,270 $ 15,381 $ 6,584 $ — $ 197,235 Inter-segment revenues — 33,554 23,228 (56,782 ) — Total revenues 175,270 48,935 29,812 (56,782 ) 197,235 Operating income (loss) (38,289 ) 10,936 18,828 (11,401 ) (19,926 ) Other income (expense) 67,359 14 — — 67,373 Income (loss) before income taxes $ 29,070 $ 10,950 $ 18,828 $ (11,401 ) $ 47,447 Nine months ended September 30, 2016: Revenues from non-affiliates $ 434,835 $ 29,459 $ 22,380 $ — $ 486,674 Inter-segment revenues — 45,023 65,650 (110,673 ) — Total revenues 434,835 74,482 88,030 (110,673 ) 486,674 Operating income (loss) (175,480 ) 3,420 49,724 (6,795 ) (129,131 ) Other income (expense) (155,595 ) 42 (462 ) — (156,015 ) Income (loss) before income taxes $ (331,075 ) $ 3,462 $ 49,262 $ (6,795 ) $ (285,146 ) Nine months ended September 30, 2015: Revenues from non-affiliates $ 563,239 $ 27,308 $ 17,121 $ — $ 607,668 Inter-segment revenues — 131,220 58,994 (190,214 ) — Total revenues 563,239 158,528 76,115 (190,214 ) 607,668 Operating income (loss) (103,065 ) 29,554 44,083 (31,570 ) (60,998 ) Other income (expense) (1,037 ) 34 (44 ) — (1,047 ) Income (loss) before income taxes $ (104,102 ) $ 29,588 $ 44,039 $ (31,570 ) $ (62,045 ) At September 30, 2016: Property, plant and equipment, net $ 4,883,137 $ 50,477 $ 391,282 $ (172,223 ) $ 5,152,673 Total assets (1) 5,120,567 53,235 396,682 (172,223 ) 5,398,261 At December 31, 2015: Property, plant and equipment, net $ 5,057,311 $ 61,402 $ 264,956 $ (165,427 ) $ 5,218,242 Total assets (1)(2) 5,478,439 66,952 269,411 (165,427 ) 5,649,375 ___________________ (1) Intercompany receivables (payables) for all segments were reclassified to capital contributions from (distributions to) parent and not included in total assets. (2) At December 31, 2015, total assets included assets held for sale of $26.7 million in the exploration and production segment related to the assets sold as of April 1, 2016 (see Note 7 – Divestiture).

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Included below is a discussion of the Company’s various future commitments as of September 30, 2016 . The commitments under these arrangements are not recorded in the accompanying Condensed Consolidated Balance Sheet. The amounts disclosed represent undiscounted cash flows on a gross basis, and no inflation elements have been applied. Lease obligations. The Company’s total rental commitments under leases for office space and other property and equipment as of September 30, 2016 were $20.7 million . Volume commitment agreements. As of September 30, 2016 , the Company had certain agreements with an aggregate requirement to deliver or transport a minimum quantity of approximately 43.8 MMBbl of crude oil, 23.0 MMBbl of natural gas liquids and 216.7 Bcf of natural gas, prior to any applicable volume credits, within specified timeframes, all of which are ten years or less. The future commitments under certain agreements cannot be estimated as they are based on fixed differentials relative to WTI under the agreements as compared to the differential relative to WTI for the Williston Basin for the production month. The estimable future commitments under these agreements were approximately $443.1 million as of September 30, 2016 . Purchase agreements . As of September 30, 2016 , the Company had certain agreements for the purchase of fresh water with an aggregate future commitment of approximately $ 38.4 million . Litigation. The Company is party to various legal and/or regulatory proceedings from time to time arising in the ordinary course of business. While the ultimate outcome and impact to the Company cannot be predicted with certainty, the Company believes that all such matters are without merit and involve amounts which, if resolved unfavorably, either individually or in the aggregate, will not have a material adverse effect on its financial condition, results of operations or cash flows. 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.

Condensed Consolidating Financi

Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Financial Information	Condensed Consolidating Financial Information The Notes (see Note 8 – 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 September 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 90 $ 13,686 $ — $ 13,776 Accounts receivable – oil and gas revenues — 103,128 — 103,128 Accounts receivable – joint interest and other — 77,903 — 77,903 Accounts receivable – affiliates 1,348 347,331 (348,679 ) — Inventory — 8,513 — 8,513 Prepaid expenses 413 5,680 — 6,093 Derivative instruments — 9,142 — 9,142 Other current assets — 4,290 — 4,290 Total current assets 1,851 569,673 (348,679 ) 222,845 Property, plant and equipment Oil and gas properties (successful efforts method) — 6,438,782 — 6,438,782 Other property and equipment — 580,171 — 580,171 Less: accumulated depreciation, depletion, amortization and impairment — (1,866,280 ) — (1,866,280 ) Total property, plant and equipment, net — 5,152,673 — 5,152,673 Investments in and advances to subsidiaries 4,478,149 — (4,478,149 ) — Derivative instruments — 194 — 194 Deferred income taxes 205,200 — (205,200 ) — Other assets — 22,549 — 22,549 Total assets $ 4,685,200 $ 5,745,089 $ (5,032,028 ) $ 5,398,261 LIABILITIES AND EQUITY Current liabilities Accounts payable $ — $ 7,929 $ — $ 7,929 Accounts payable – affiliates 347,331 1,348 (348,679 ) — Revenues and production taxes payable — 141,991 — 141,991 Accrued liabilities 27 98,899 — 98,926 Accrued interest payable 19,765 33 — 19,798 Derivative instruments — 17,308 — 17,308 Advances from joint interest partners — 5,191 — 5,191 Other current liabilities — — — — Total current liabilities 367,123 272,699 (348,679 ) 291,143 Long-term debt 1,930,573 195,000 — 2,125,573 Deferred income taxes — 751,402 (205,200 ) 546,202 Asset retirement obligations — 37,092 — 37,092 Derivative instruments — 7,755 — 7,755 Other liabilities — 2,992 — 2,992 Total liabilities 2,297,696 1,266,940 (553,879 ) 3,010,757 Stockholders’ equity Capital contributions from affiliates — 3,385,326 (3,385,326 ) — Common stock, $0.01 par value: 450,000,000 shares authorized; 182,038,164 shares issued and 181,186,070 shares outstanding 1,779 — — 1,779 Treasury stock, at cost: 852,094 shares (15,895 ) — — (15,895 ) Additional paid-in-capital 1,755,427 8,743 (8,743 ) 1,755,427 Retained earnings 646,193 1,084,080 (1,084,080 ) 646,193 Total stockholders’ equity 2,387,504 4,478,149 (4,478,149 ) 2,387,504 Total liabilities and stockholders’ equity $ 4,685,200 $ 5,745,089 $ (5,032,028 ) $ 5,398,261 Condensed Consolidating Balance Sheet December 31, 2015 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 777 $ 8,953 $ — $ 9,730 Accounts receivable – oil and gas revenues — 96,495 — 96,495 Accounts receivable – joint interest and other 15 100,899 — 100,914 Accounts receivable – affiliates 1,248 247,488 (248,736 ) — Inventory — 11,072 — 11,072 Prepaid expenses 278 7,050 — 7,328 Derivative instruments — 139,697 — 139,697 Other current assets — 50 — 50 Total current assets 2,318 611,704 (248,736 ) 365,286 Property, plant and equipment Oil and gas properties (successful efforts method) — 6,284,401 — 6,284,401 Other property and equipment — 443,265 — 443,265 Less: accumulated depreciation, depletion, amortization and impairment — (1,509,424 ) — (1,509,424 ) Total property, plant and equipment, net — 5,218,242 — 5,218,242 Assets held for sale — 26,728 — 26,728 Investments in and advances to subsidiaries 4,573,172 — (4,573,172 ) — Derivative instruments — 15,776 — 15,776 Deferred income taxes 205,174 — (205,174 ) — Other assets 100 23,243 — 23,343 Total assets $ 4,780,764 $ 5,895,693 $ (5,027,082 ) $ 5,649,375 LIABILITIES AND EQUITY Current liabilities Accounts payable $ — $ 9,983 $ — $ 9,983 Accounts payable – affiliates 247,488 1,248 (248,736 ) — Revenue and production taxes payable — 132,356 — 132,356 Accrued liabilities 10 167,659 — 167,669 Accrued interest payable 49,340 73 — 49,413 Advances from joint interest partners — 4,647 — 4,647 Other current liabilities — 6,500 — 6,500 Total current liabilities 296,838 322,466 (248,736 ) 370,568 Long-term debt 2,164,584 138,000 — 2,302,584 Deferred income taxes — 813,329 (205,174 ) 608,155 Asset retirement obligations — 35,338 — 35,338 Liabilities held for sale — 10,228 — 10,228 Other liabilities — 3,160 — 3,160 Total liabilities 2,461,422 1,322,521 (453,910 ) 3,330,033 Stockholders’ equity Capital contributions from affiliates — 3,369,895 (3,369,895 ) — Common stock, $0.01 par value: 300,000,000 shares authorized; 139,583,990 shares issued and 139,076,064 shares outstanding 1,376 — — 1,376 Treasury stock, at cost: 507,926 shares (13,620 ) — — (13,620 ) Additional paid-in-capital 1,497,065 8,743 (8,743 ) 1,497,065 Retained earnings 834,521 1,194,534 (1,194,534 ) 834,521 Total stockholders’ equity 2,319,342 4,573,172 (4,573,172 ) 2,319,342 Total liabilities and stockholders’ equity $ 4,780,764 $ 5,895,693 $ (5,027,082 ) $ 5,649,375 Condensed Consolidating Statement of Operations Three Months Ended September 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 158,183 $ — $ 158,183 Well services and midstream revenues — 19,128 — 19,128 Total revenues — 177,311 — 177,311 Operating expenses Lease operating expenses — 35,696 — 35,696 Well services and midstream operating expenses — 8,165 — 8,165 Marketing, transportation and gathering expenses — 8,856 — 8,856 Production taxes — 14,638 — 14,638 Depreciation, depletion and amortization — 111,948 — 111,948 Exploration expenses — 489 — 489 Impairment — 382 — 382 General and administrative expenses 5,930 16,915 — 22,845 Total operating expenses 5,930 197,089 — 203,019 Gain on sale of properties — 6 — 6 Operating loss (5,930 ) (19,772 ) — (25,702 ) Other income (expense) Equity in loss of subsidiaries (1,140 ) — 1,140 — Net gain on derivative instruments — 20,847 — 20,847 Interest expense, net of capitalized interest (29,876 ) (1,850 ) — (31,726 ) Loss on extinguishment of debt (13,793 ) — — (13,793 ) Other income (expense) 1 (260 ) — (259 ) Total other income (expense) (44,808 ) 18,737 1,140 (24,931 ) Loss before income taxes (50,738 ) (1,035 ) 1,140 (50,633 ) Income tax benefit (expense) 16,796 (105 ) — 16,691 Net loss $ (33,942 ) $ (1,140 ) $ 1,140 $ (33,942 ) Condensed Consolidating Statement of Operations Three Months Ended September 30, 2015 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 175,270 $ — $ 175,270 Well services and midstream revenues — 21,965 — 21,965 Total revenues — 197,235 — 197,235 Operating expenses Lease operating expenses — 35,670 — 35,670 Well services and midstream operating expenses — 10,023 — 10,023 Marketing, transportation and gathering expenses — 8,465 — 8,465 Production taxes — 16,676 — 16,676 Depreciation, depletion and amortization — 123,734 — 123,734 Exploration expenses — 327 — 327 Impairment — 80 — 80 General and administrative expenses 5,903 16,455 — 22,358 Total operating expenses 5,903 211,430 — 217,333 Gain on sale of properties — 172 — 172 Operating loss (5,903 ) (14,023 ) — (19,926 ) Other income (expense) Equity in earnings of subsidiaries 49,899 — (49,899 ) — Net gain on derivative instruments — 103,637 — 103,637 Interest expense, net of capitalized interest (34,020 ) (2,493 ) — (36,513 ) Other income 1 248 — 249 Total other income (expense) 15,880 101,392 (49,899 ) 67,373 Income before income taxes 9,977 87,369 (49,899 ) 47,447 Income tax benefit (expense) 17,078 (37,470 ) — (20,392 ) Net income $ 27,055 $ 49,899 $ (49,899 ) $ 27,055 Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2016 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 434,835 $ — $ 434,835 Well services and midstream revenues — 51,839 — 51,839 Total revenues — 486,674 — 486,674 Operating expenses Lease operating expenses — 98,283 — 98,283 Well services and midstream operating expenses — 21,429 — 21,429 Marketing, transportation and gathering expenses — 23,899 — 23,899 Production taxes — 39,758 — 39,758 Depreciation, depletion and amortization — 356,885 — 356,885 Exploration expenses — 1,192 — 1,192 Impairment — 3,967 — 3,967 General and administrative expenses 19,776 49,311 — 69,087 Total operating expenses 19,776 594,724 — 614,500 Loss on sale of properties — (1,305 ) — (1,305 ) Operating loss (19,776 ) (109,355 ) — (129,131 ) Other income (expense) Equity in loss of subsidiaries (110,454 ) — 110,454 — Net loss on derivative instruments — (55,624 ) — (55,624 ) Interest expense, net of capitalized interest (97,898 ) (7,546 ) — (105,444 ) Gain on extinguishment of debt 4,865 — — 4,865 Other income 44 144 — 188 Total other income (expense) (203,443 ) (63,026 ) 110,454 (156,015 ) Loss before income taxes (223,219 ) (172,381 ) 110,454 (285,146 ) Income tax benefit 34,891 61,927 — 96,818 Net loss $ (188,328 ) $ (110,454 ) $ 110,454 $ (188,328 ) Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2015 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 563,239 $ — $ 563,239 Well services and midstream revenues — 44,429 — 44,429 Total revenues — 607,668 — 607,668 Operating expenses Lease operating expenses — 112,556 — 112,556 Well services and midstream operating expenses — 19,370 — 19,370 Marketing, transportation and gathering expenses — 23,313 — 23,313 Production taxes — 53,915 — 53,915 Depreciation, depletion and amortization — 361,430 — 361,430 Exploration expenses — 2,252 — 2,252 Rig termination — 3,895 — 3,895 Impairment — 24,917 — 24,917 General and administrative expenses 20,847 46,343 — 67,190 Total operating expenses 20,847 647,991 — 668,838 Gain on sale of properties — 172 — 172 Operating loss (20,847 ) (40,151 ) — (60,998 ) Other income (expense) Equity in earnings of subsidiaries 28,269 — (28,269 ) — Net gain on derivative instruments — 111,285 — 111,285 Interest expense, net of capitalized interest (103,435 ) (9,267 ) — (112,702 ) Other income 5 365 — 370 Total other income (expense) (75,161 ) 102,383 (28,269 ) (1,047 ) Income (loss) before income taxes (96,008 ) 62,232 (28,269 ) (62,045 ) Income tax benefit (expense) 51,792 (33,963 ) — 17,829 Net income (loss) $ (44,216 ) $ 28,269 $ (28,269 ) $ (44,216 ) Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net loss $ (188,328 ) $ (110,454 ) $ 110,454 $ (188,328 ) Adjustments to reconcile net loss to cash provided by (used in) operating activities: Equity in loss of subsidiaries 110,454 — (110,454 ) — Depreciation, depletion and amortization — 356,885 — 356,885 Gain on extinguishment of debt (4,865 ) — — (4,865 ) Loss on sale of properties — 1,305 — 1,305 Impairment — 3,967 — 3,967 Deferred income taxes (34,891 ) (61,927 ) — (96,818 ) Derivative instruments — 55,624 — 55,624 Stock-based compensation expenses 18,195 566 — 18,761 Deferred financing costs amortization and other 5,371 4,803 — 10,174 Working capital and other changes: Change in accounts receivable (85 ) (88,509 ) 99,943 11,349 Change in inventory — 2,559 — 2,559 Change in prepaid expenses (135 ) 1,303 — 1,168 Change in other current assets — (240 ) — (240 ) Change in other assets 100 (248 ) — (148 ) Change in accounts payable, interest payable and accrued liabilities 70,285 (12,333 ) (99,943 ) (41,991 ) Change in other current liabilities — (6,000 ) — (6,000 ) Change in other liabilities — 17 — 17 Net cash provided by (used in) operating activities (23,899 ) 147,318 — 123,419 Cash flows from investing activities: Capital expenditures — (340,314 ) — (340,314 ) Proceeds from sale of properties — 12,333 — 12,333 Costs related to sale of properties — (310 ) — (310 ) Derivative settlements — 115,576 — 115,576 Advances from joint interest partners — 544 — 544 Net cash used in investing activities — (212,171 ) — (212,171 ) Cash flows from financing activities: Repurchase of senior unsecured notes (435,907 ) — — (435,907 ) Proceeds from issuance of senior unsecured convertible notes 300,000 — — 300,000 Proceeds from revolving credit facility — 835,000 — 835,000 Principal payments on revolving credit facility — (778,000 ) — (778,000 ) Deferred financing costs (7,880 ) (931 ) — (8,811 ) Proceeds from sale of common stock 182,791 — — 182,791 Purchases of treasury stock (2,275 ) — — (2,275 ) Investment in / capital contributions from subsidiaries (13,517 ) 13,517 — — Net cash provided by financing activities 23,212 69,586 — 92,798 Increase (decrease) in cash and cash equivalents (687 ) 4,733 — 4,046 Cash and cash equivalents at beginning of period 777 8,953 — 9,730 Cash and cash equivalents at end of period $ 90 $ 13,686 $ — $ 13,776 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2015 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net income (loss) $ (44,216 ) $ 28,269 $ (28,269 ) $ (44,216 ) Adjustments to reconcile net income (loss) to cash provided by operating activities: Equity in earnings of subsidiaries (28,269 ) — 28,269 — Depreciation, depletion and amortization — 361,430 — 361,430 Gain on sale of properties — (172 ) — (172 ) Impairment — 24,917 — 24,917 Deferred income taxes (51,792 ) 33,963 — (17,829 ) Derivative instruments — (111,285 ) — (111,285 ) Stock-based compensation expenses 19,276 353 — 19,629 Deferred financing costs amortization and other 3,401 4,067 — 7,468 Working capital and other changes: Change in accounts receivable (493 ) (22,000 ) 130,802 108,309 Change in inventory — 8,425 — 8,425 Change in prepaid expenses (120 ) 758 — 638 Change in other current assets — 5,529 — 5,529 Change in accounts payable, interest payable and accrued liabilities 105,536 (58,867 ) (130,802 ) (84,133 ) Change in other current liabilities — 1,655 — 1,655 Change in other liabilities — (28 ) — (28 ) Net cash provided by operating activities 3,323 277,014 — 280,337 Cash flows from investing activities: Capital expenditures — (740,633 ) — (740,633 ) Proceeds from sale of properties — 78 — 78 Derivative settlements — 291,436 — 291,436 Advances from joint interest partners — (1,239 ) — (1,239 ) Net cash used in investing activities — (450,358 ) — (450,358 ) Cash flows from financing activities: Proceeds from revolving credit facility — 618,000 — 618,000 Principal payments on revolving credit facility — (938,000 ) — (938,000 ) Deferred financing costs — (3,587 ) — (3,587 ) Proceeds from sale of common stock 462,833 — — 462,833 Purchases of treasury stock (2,771 ) — — (2,771 ) Investment in / capital contributions from subsidiaries (463,404 ) 463,404 — — Net cash provided by (used in) financing activities (3,342 ) 139,817 — 136,475 Decrease in cash and cash equivalents (19 ) (33,527 ) — (33,546 ) Cash and cash equivalents at beginning of period 776 45,035 — 45,811 Cash and cash equivalents at end of period $ 757 $ 11,508 $ — $ 12,265

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2016
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 October 2016, the Company entered into new swaps and two-way and three-way costless collar options for crude oil and natural gas with weighted average floor prices of $51.73 per barrel and $3.38 per MMBtu, respectively. The commodity contracts included total notional amounts of 2,338,000 barrels, 1,219,000 barrels and 93,000 barrels, which settle in 2017, 2018 and 2019, respectively, based on WTI and 668,000 MMBtu and 62,000 MMBtu, which settle in 2017 and 2018, respectively, based on Henry Hub. These derivative instruments do not qualify for and were not designated as hedging instruments for accounting purposes. Credit facility amendment. On October 14, 2016, the Company entered into an amendment to its Credit Facility in connection with the scheduled redetermination of its borrowing base. Following the redetermination, the borrowing base and elected commitments were reaffirmed at $1,150.0 million . The next redetermination of the Company’s borrowing base is scheduled for April 1, 2017. Acquisition. On October 17, 2016, the Company signed a purchase and sale agreement (the “Purchase Agreement”) with SM Energy Company to acquire approximately 55,000 net acres in the Williston Basin for approximately $785.0 million (the “Williston Basin Acquisition”). The effective date for the Williston Basin Acquisition is October 1, 2016 and the transaction is expected to close on December 1, 2016. The transaction is subject to customary closing conditions. The Purchase Agreement contains various purchase price adjustments to be calculated as of the closing date. The Company will fund the Williston Basin Acquisition with the proceeds from its October 2016 public equity offering discussed below and borrowings under its Credit Facility. The Williston Basin Acquisition will be accounted for as a business combination. Sale of common stock. On October 21, 2016, the Company completed a public offering of 55,200,000 shares of its common stock (including 7,200,000 shares issued pursuant to the underwriters’ option to purchase additional common stock) at a purchase price to the public of $10.80 per share. Net proceeds from the offering were approximately $584.0 million , after deducting underwriting discounts and commissions and estimated offering expenses. The Company intends to use the net proceeds to fund a portion of the Williston Basin Acquisition. The offering was not conditioned on the consummation of the Williston Basin Acquisition, and if the Williston Basin Acquisition does not close, the net proceeds will be used for general corporate purposes, which may include funding a portion of the Company’s 2017 capital budget. The offering was made pursuant to an effective shelf registration statement on Form S-3 filed with the SEC on July 15, 2014.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
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, 2015 is derived from audited financial statements. 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, 2015 (“ 2015 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. Oil and natural gas prices have declined significantly since mid-2014. As a result of sustained lower commodity prices, the Company decreased its 2016 capital expenditures, excluding acquisitions, as compared to 2015 and continues to concentrate its drilling activities in certain areas that are the most economic in the Williston Basin. 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.
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. Going concern. In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 codifies in GAAP management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 is effective for the annual reporting period ending after December 15, 2016 and for annual periods and interim periods thereafter. The adoption of this guidance will not impact the Company’s financial position, cash flows or results of operations but could result in additional disclosures. Inventory. In July 2015, the FASB issued Accounting Standards Update No. 2015-11, Simplifying the Measurement of Inventory (“ASU 2015-11”). ASU 2015-11 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 is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. The Company does not expect the adoption of this guidance to have a material impact on its financial position, cash flows or 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. Embedded derivatives. In March 2016, the FASB issued Accounting Standards Update No. 2016-06, Contingent Put and Call Options in Debt Instruments (“ASU 2016-06”), which clarifies what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. ASU 2016-06 is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. The Company does not expect the adoption of this guidance to have a material impact on its financial position, cash flows or results of operations. Stock-based compensation. In March 2016, the FASB issued 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. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. The Company will record a cumulative-effect adjustment to equity at the beginning of 2017 when the guidance is adopted and does not expect the adoption of this guidance to have a material impact on its cash flows or 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 statement of cash flows.

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2016
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consists of the following: September 30, 2016 December 31, 2015 (In thousands) Crude oil inventory $ 5,344 $ 6,152 Equipment and materials 3,169 4,920 Total inventory $ 8,513 $ 11,072

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
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 September 30, 2016 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 54 $ — $ — $ 54 Commodity derivative instruments (see Note 5) — 9,336 — 9,336 Total assets $ 54 $ 9,336 $ — $ 9,390 Liabilities: Commodity derivative instruments (see Note 5) $ — $ 25,063 $ — $ 25,063 Total liabilities $ — $ 25,063 $ — $ 25,063 Fair value at December 31, 2015 Level 1 Level 2 Level 3 Total (In thousands) Assets: Money market funds $ 742 $ — $ — $ 742 Commodity derivative instruments (see Note 5) — 155,473 — 155,473 Total assets $ 742 $ 155,473 $ — $ 156,215

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Outstanding Commodity Derivative Instruments	At September 30, 2016 , 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 2016 Swaps 2,973,000 Bbl $ 49.18 $ 4,765 Crude oil 2017 Swaps 5,059,000 Bbl $ 48.04 (14,742 ) Crude oil 2017 Two-way collar 1,002,000 Bbl $ 41.67 $ 50.58 (4,092 ) Crude oil 2017 Three-way collar 1,670,000 Bbl $ 30.00 $ 45.00 $ 60.11 241 Crude oil 2018 Swaps 522,000 Bbl $ 50.07 (1,349 ) Crude oil 2018 Two-way collar 93,000 Bbl $ 41.67 $ 50.58 (471 ) Crude oil 2018 Three-way collar 155,000 Bbl $ 30.00 $ 45.00 $ 60.11 (122 ) Natural gas 2017 Swaps 1,336,000 MMbtu $ 3.12 52 Natural gas 2018 Swaps 124,000 MMbtu $ 3.12 (9 ) $ (15,727 )
Schedule of Location and Fair Value of Outstanding Commodity Derivative Instruments	The following table summarizes the location and fair value of all outstanding commodity derivative instruments recorded in the Company’s Condensed Consolidated Balance Sheet: Fair Value Asset (Liability) Type Balance Sheet Location September 30, 2016 December 31, 2015 (In thousands) Commodity contracts Derivative instruments — current assets $ 9,142 $ 139,697 Commodity contracts Derivative instruments — non-current assets 194 15,776 Commodity contracts Derivative instruments — current liabilities (17,308 ) — Commodity contracts Derivative instruments — non-current liabilities (7,755 ) — Total derivative instruments $ (15,727 ) $ 155,473
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 Statement of Operations for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, Statement of Operations Location 2016 2015 2016 2015 (In thousands) Net gain (loss) on derivative instruments $ 20,847 $ 103,637 $ (55,624 ) $ 111,285
Summary of Gross and Net Information about Commodity Derivative Assets	The following tables summarize gross and net information about the Company’s commodity derivative instruments: Offsetting of Derivative Assets Gross Amounts of Recognized Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet (In thousands) At September 30, 2016 $ 23,713 $ (14,377 ) $ 9,336 At December 31, 2015 155,473 — 155,473
Summary of Gross and Net Information about Commodity Derivative Liabilities	Offsetting of Derivative Liabilities Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Balance Sheet Net Amounts of Liabilities Presented in the Balance Sheet (In thousands) At September 30, 2016 $ 39,440 $ (14,377 ) $ 25,063 At December 31, 2015 — — —

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	The following table sets forth the Company’s property, plant and equipment: September 30, 2016 December 31, 2015 (In thousands) Proved oil and gas properties (1) $ 5,813,928 $ 5,655,759 Less: accumulated depreciation, depletion, amortization and impairment (1,764,979 ) (1,428,427 ) Proved oil and gas properties, net 4,048,949 4,227,332 Unproved oil and gas properties 624,854 628,642 Other property and equipment 580,171 443,265 Less: accumulated depreciation (101,301 ) (80,997 ) Other property and equipment, net 478,870 362,268 Total property, plant and equipment, net $ 5,152,673 $ 5,218,242 __________________ (1) Included in the Company’s proved oil and gas properties are estimates of future asset retirement costs of $31.5 million and $30.7 million at September 30, 2016 and December 31, 2015 , respectively.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	The Company’s long-term debt consists of the following: September 30, 2016 December 31, 2015 (In thousands) Senior secured revolving line of credit $ 195,000 $ 138,000 Senior unsecured notes 7.25% senior unsecured notes due February 1, 2019 54,275 400,000 6.5% senior unsecured notes due November 1, 2021 395,501 400,000 6.875% senior unsecured notes due March 15, 2022 937,080 1,000,000 6.875% senior unsecured notes due January 15, 2023 366,094 400,000 2.625% senior unsecured convertible notes due September 15, 2023 300,000 — Total principal of senior unsecured notes 2,052,950 2,200,000 Less: unamortized deferred financing costs on senior unsecured notes (29,500 ) (35,416 ) Less: unamortized debt discount on senior unsecured convertible notes (92,877 ) — Total long-term debt $ 2,125,573 $ 2,302,584

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2016
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 nine months ended September 30, 2016 : (In thousands) Balance at December 31, 2015 $ 35,812 Liabilities incurred during period 465 Liabilities settled during period (1) (444 ) Accretion expense during period (2) 1,425 Revisions to estimates 571 Balance at September 30, 2016 $ 37,829 ___________________ (1) Liabilities settled during the nine months ended September 30, 2016 included ARO related to the sold properties (see Note 7 – Divestiture). (2) Included in depreciation, depletion and amortization on the Company’s Condensed Consolidated Statement of Operations.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
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 nine months ended September 30, 2016 : Forecast period (years) 4.00 Risk-free interest rate 1.25 % Oasis stock price volatility 59.38 %

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
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 nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (In thousands) Basic weighted average common shares outstanding 177,120 137,014 172,360 127,827 Dilution effect of stock awards at end of period — — — — Diluted weighted average common shares outstanding 177,120 137,014 172,360 127,827

Business Segment Information (T

Business Segment Information (Tables)	9 Months Ended
	Sep. 30, 2016
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 Well Services Midstream Services Eliminations Consolidated (In thousands) Three months ended September 30, 2016: Revenues from non-affiliates $ 158,183 $ 10,641 $ 8,487 $ — $ 177,311 Inter-segment revenues — 11,818 20,790 (32,608 ) — Total revenues 158,183 22,459 29,277 (32,608 ) 177,311 Operating income (loss) (41,857 ) 1,572 16,525 (1,942 ) (25,702 ) Other income (expense) (24,476 ) 5 (460 ) — (24,931 ) Income (loss) before income taxes $ (66,333 ) $ 1,577 $ 16,065 $ (1,942 ) $ (50,633 ) Three months ended September 30, 2015: Revenues from non-affiliates $ 175,270 $ 15,381 $ 6,584 $ — $ 197,235 Inter-segment revenues — 33,554 23,228 (56,782 ) — Total revenues 175,270 48,935 29,812 (56,782 ) 197,235 Operating income (loss) (38,289 ) 10,936 18,828 (11,401 ) (19,926 ) Other income (expense) 67,359 14 — — 67,373 Income (loss) before income taxes $ 29,070 $ 10,950 $ 18,828 $ (11,401 ) $ 47,447 Nine months ended September 30, 2016: Revenues from non-affiliates $ 434,835 $ 29,459 $ 22,380 $ — $ 486,674 Inter-segment revenues — 45,023 65,650 (110,673 ) — Total revenues 434,835 74,482 88,030 (110,673 ) 486,674 Operating income (loss) (175,480 ) 3,420 49,724 (6,795 ) (129,131 ) Other income (expense) (155,595 ) 42 (462 ) — (156,015 ) Income (loss) before income taxes $ (331,075 ) $ 3,462 $ 49,262 $ (6,795 ) $ (285,146 ) Nine months ended September 30, 2015: Revenues from non-affiliates $ 563,239 $ 27,308 $ 17,121 $ — $ 607,668 Inter-segment revenues — 131,220 58,994 (190,214 ) — Total revenues 563,239 158,528 76,115 (190,214 ) 607,668 Operating income (loss) (103,065 ) 29,554 44,083 (31,570 ) (60,998 ) Other income (expense) (1,037 ) 34 (44 ) — (1,047 ) Income (loss) before income taxes $ (104,102 ) $ 29,588 $ 44,039 $ (31,570 ) $ (62,045 ) At September 30, 2016: Property, plant and equipment, net $ 4,883,137 $ 50,477 $ 391,282 $ (172,223 ) $ 5,152,673 Total assets (1) 5,120,567 53,235 396,682 (172,223 ) 5,398,261 At December 31, 2015: Property, plant and equipment, net $ 5,057,311 $ 61,402 $ 264,956 $ (165,427 ) $ 5,218,242 Total assets (1)(2) 5,478,439 66,952 269,411 (165,427 ) 5,649,375 ___________________ (1) Intercompany receivables (payables) for all segments were reclassified to capital contributions from (distributions to) parent and not included in total assets. (2) At December 31, 2015, total assets included assets held for sale of $26.7 million in the exploration and production segment related to the assets sold as of April 1, 2016 (see Note 7 – Divestiture).

Condensed Consolidating Finan34

Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet September 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 90 $ 13,686 $ — $ 13,776 Accounts receivable – oil and gas revenues — 103,128 — 103,128 Accounts receivable – joint interest and other — 77,903 — 77,903 Accounts receivable – affiliates 1,348 347,331 (348,679 ) — Inventory — 8,513 — 8,513 Prepaid expenses 413 5,680 — 6,093 Derivative instruments — 9,142 — 9,142 Other current assets — 4,290 — 4,290 Total current assets 1,851 569,673 (348,679 ) 222,845 Property, plant and equipment Oil and gas properties (successful efforts method) — 6,438,782 — 6,438,782 Other property and equipment — 580,171 — 580,171 Less: accumulated depreciation, depletion, amortization and impairment — (1,866,280 ) — (1,866,280 ) Total property, plant and equipment, net — 5,152,673 — 5,152,673 Investments in and advances to subsidiaries 4,478,149 — (4,478,149 ) — Derivative instruments — 194 — 194 Deferred income taxes 205,200 — (205,200 ) — Other assets — 22,549 — 22,549 Total assets $ 4,685,200 $ 5,745,089 $ (5,032,028 ) $ 5,398,261 LIABILITIES AND EQUITY Current liabilities Accounts payable $ — $ 7,929 $ — $ 7,929 Accounts payable – affiliates 347,331 1,348 (348,679 ) — Revenues and production taxes payable — 141,991 — 141,991 Accrued liabilities 27 98,899 — 98,926 Accrued interest payable 19,765 33 — 19,798 Derivative instruments — 17,308 — 17,308 Advances from joint interest partners — 5,191 — 5,191 Other current liabilities — — — — Total current liabilities 367,123 272,699 (348,679 ) 291,143 Long-term debt 1,930,573 195,000 — 2,125,573 Deferred income taxes — 751,402 (205,200 ) 546,202 Asset retirement obligations — 37,092 — 37,092 Derivative instruments — 7,755 — 7,755 Other liabilities — 2,992 — 2,992 Total liabilities 2,297,696 1,266,940 (553,879 ) 3,010,757 Stockholders’ equity Capital contributions from affiliates — 3,385,326 (3,385,326 ) — Common stock, $0.01 par value: 450,000,000 shares authorized; 182,038,164 shares issued and 181,186,070 shares outstanding 1,779 — — 1,779 Treasury stock, at cost: 852,094 shares (15,895 ) — — (15,895 ) Additional paid-in-capital 1,755,427 8,743 (8,743 ) 1,755,427 Retained earnings 646,193 1,084,080 (1,084,080 ) 646,193 Total stockholders’ equity 2,387,504 4,478,149 (4,478,149 ) 2,387,504 Total liabilities and stockholders’ equity $ 4,685,200 $ 5,745,089 $ (5,032,028 ) $ 5,398,261 Condensed Consolidating Balance Sheet December 31, 2015 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) ASSETS Current assets Cash and cash equivalents $ 777 $ 8,953 $ — $ 9,730 Accounts receivable – oil and gas revenues — 96,495 — 96,495 Accounts receivable – joint interest and other 15 100,899 — 100,914 Accounts receivable – affiliates 1,248 247,488 (248,736 ) — Inventory — 11,072 — 11,072 Prepaid expenses 278 7,050 — 7,328 Derivative instruments — 139,697 — 139,697 Other current assets — 50 — 50 Total current assets 2,318 611,704 (248,736 ) 365,286 Property, plant and equipment Oil and gas properties (successful efforts method) — 6,284,401 — 6,284,401 Other property and equipment — 443,265 — 443,265 Less: accumulated depreciation, depletion, amortization and impairment — (1,509,424 ) — (1,509,424 ) Total property, plant and equipment, net — 5,218,242 — 5,218,242 Assets held for sale — 26,728 — 26,728 Investments in and advances to subsidiaries 4,573,172 — (4,573,172 ) — Derivative instruments — 15,776 — 15,776 Deferred income taxes 205,174 — (205,174 ) — Other assets 100 23,243 — 23,343 Total assets $ 4,780,764 $ 5,895,693 $ (5,027,082 ) $ 5,649,375 LIABILITIES AND EQUITY Current liabilities Accounts payable $ — $ 9,983 $ — $ 9,983 Accounts payable – affiliates 247,488 1,248 (248,736 ) — Revenue and production taxes payable — 132,356 — 132,356 Accrued liabilities 10 167,659 — 167,669 Accrued interest payable 49,340 73 — 49,413 Advances from joint interest partners — 4,647 — 4,647 Other current liabilities — 6,500 — 6,500 Total current liabilities 296,838 322,466 (248,736 ) 370,568 Long-term debt 2,164,584 138,000 — 2,302,584 Deferred income taxes — 813,329 (205,174 ) 608,155 Asset retirement obligations — 35,338 — 35,338 Liabilities held for sale — 10,228 — 10,228 Other liabilities — 3,160 — 3,160 Total liabilities 2,461,422 1,322,521 (453,910 ) 3,330,033 Stockholders’ equity Capital contributions from affiliates — 3,369,895 (3,369,895 ) — Common stock, $0.01 par value: 300,000,000 shares authorized; 139,583,990 shares issued and 139,076,064 shares outstanding 1,376 — — 1,376 Treasury stock, at cost: 507,926 shares (13,620 ) — — (13,620 ) Additional paid-in-capital 1,497,065 8,743 (8,743 ) 1,497,065 Retained earnings 834,521 1,194,534 (1,194,534 ) 834,521 Total stockholders’ equity 2,319,342 4,573,172 (4,573,172 ) 2,319,342 Total liabilities and stockholders’ equity $ 4,780,764 $ 5,895,693 $ (5,027,082 ) $ 5,649,375
Condensed Consolidating Statement of Operations	Condensed Consolidating Statement of Operations Three Months Ended September 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 158,183 $ — $ 158,183 Well services and midstream revenues — 19,128 — 19,128 Total revenues — 177,311 — 177,311 Operating expenses Lease operating expenses — 35,696 — 35,696 Well services and midstream operating expenses — 8,165 — 8,165 Marketing, transportation and gathering expenses — 8,856 — 8,856 Production taxes — 14,638 — 14,638 Depreciation, depletion and amortization — 111,948 — 111,948 Exploration expenses — 489 — 489 Impairment — 382 — 382 General and administrative expenses 5,930 16,915 — 22,845 Total operating expenses 5,930 197,089 — 203,019 Gain on sale of properties — 6 — 6 Operating loss (5,930 ) (19,772 ) — (25,702 ) Other income (expense) Equity in loss of subsidiaries (1,140 ) — 1,140 — Net gain on derivative instruments — 20,847 — 20,847 Interest expense, net of capitalized interest (29,876 ) (1,850 ) — (31,726 ) Loss on extinguishment of debt (13,793 ) — — (13,793 ) Other income (expense) 1 (260 ) — (259 ) Total other income (expense) (44,808 ) 18,737 1,140 (24,931 ) Loss before income taxes (50,738 ) (1,035 ) 1,140 (50,633 ) Income tax benefit (expense) 16,796 (105 ) — 16,691 Net loss $ (33,942 ) $ (1,140 ) $ 1,140 $ (33,942 ) Condensed Consolidating Statement of Operations Three Months Ended September 30, 2015 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 175,270 $ — $ 175,270 Well services and midstream revenues — 21,965 — 21,965 Total revenues — 197,235 — 197,235 Operating expenses Lease operating expenses — 35,670 — 35,670 Well services and midstream operating expenses — 10,023 — 10,023 Marketing, transportation and gathering expenses — 8,465 — 8,465 Production taxes — 16,676 — 16,676 Depreciation, depletion and amortization — 123,734 — 123,734 Exploration expenses — 327 — 327 Impairment — 80 — 80 General and administrative expenses 5,903 16,455 — 22,358 Total operating expenses 5,903 211,430 — 217,333 Gain on sale of properties — 172 — 172 Operating loss (5,903 ) (14,023 ) — (19,926 ) Other income (expense) Equity in earnings of subsidiaries 49,899 — (49,899 ) — Net gain on derivative instruments — 103,637 — 103,637 Interest expense, net of capitalized interest (34,020 ) (2,493 ) — (36,513 ) Other income 1 248 — 249 Total other income (expense) 15,880 101,392 (49,899 ) 67,373 Income before income taxes 9,977 87,369 (49,899 ) 47,447 Income tax benefit (expense) 17,078 (37,470 ) — (20,392 ) Net income $ 27,055 $ 49,899 $ (49,899 ) $ 27,055 Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2016 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 434,835 $ — $ 434,835 Well services and midstream revenues — 51,839 — 51,839 Total revenues — 486,674 — 486,674 Operating expenses Lease operating expenses — 98,283 — 98,283 Well services and midstream operating expenses — 21,429 — 21,429 Marketing, transportation and gathering expenses — 23,899 — 23,899 Production taxes — 39,758 — 39,758 Depreciation, depletion and amortization — 356,885 — 356,885 Exploration expenses — 1,192 — 1,192 Impairment — 3,967 — 3,967 General and administrative expenses 19,776 49,311 — 69,087 Total operating expenses 19,776 594,724 — 614,500 Loss on sale of properties — (1,305 ) — (1,305 ) Operating loss (19,776 ) (109,355 ) — (129,131 ) Other income (expense) Equity in loss of subsidiaries (110,454 ) — 110,454 — Net loss on derivative instruments — (55,624 ) — (55,624 ) Interest expense, net of capitalized interest (97,898 ) (7,546 ) — (105,444 ) Gain on extinguishment of debt 4,865 — — 4,865 Other income 44 144 — 188 Total other income (expense) (203,443 ) (63,026 ) 110,454 (156,015 ) Loss before income taxes (223,219 ) (172,381 ) 110,454 (285,146 ) Income tax benefit 34,891 61,927 — 96,818 Net loss $ (188,328 ) $ (110,454 ) $ 110,454 $ (188,328 ) Condensed Consolidating Statement of Operations Nine Months Ended September 30, 2015 Parent/ Combined Intercompany Consolidated (In thousands) Revenues Oil and gas revenues $ — $ 563,239 $ — $ 563,239 Well services and midstream revenues — 44,429 — 44,429 Total revenues — 607,668 — 607,668 Operating expenses Lease operating expenses — 112,556 — 112,556 Well services and midstream operating expenses — 19,370 — 19,370 Marketing, transportation and gathering expenses — 23,313 — 23,313 Production taxes — 53,915 — 53,915 Depreciation, depletion and amortization — 361,430 — 361,430 Exploration expenses — 2,252 — 2,252 Rig termination — 3,895 — 3,895 Impairment — 24,917 — 24,917 General and administrative expenses 20,847 46,343 — 67,190 Total operating expenses 20,847 647,991 — 668,838 Gain on sale of properties — 172 — 172 Operating loss (20,847 ) (40,151 ) — (60,998 ) Other income (expense) Equity in earnings of subsidiaries 28,269 — (28,269 ) — Net gain on derivative instruments — 111,285 — 111,285 Interest expense, net of capitalized interest (103,435 ) (9,267 ) — (112,702 ) Other income 5 365 — 370 Total other income (expense) (75,161 ) 102,383 (28,269 ) (1,047 ) Income (loss) before income taxes (96,008 ) 62,232 (28,269 ) (62,045 ) Income tax benefit (expense) 51,792 (33,963 ) — 17,829 Net income (loss) $ (44,216 ) $ 28,269 $ (28,269 ) $ (44,216 )
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2016 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net loss $ (188,328 ) $ (110,454 ) $ 110,454 $ (188,328 ) Adjustments to reconcile net loss to cash provided by (used in) operating activities: Equity in loss of subsidiaries 110,454 — (110,454 ) — Depreciation, depletion and amortization — 356,885 — 356,885 Gain on extinguishment of debt (4,865 ) — — (4,865 ) Loss on sale of properties — 1,305 — 1,305 Impairment — 3,967 — 3,967 Deferred income taxes (34,891 ) (61,927 ) — (96,818 ) Derivative instruments — 55,624 — 55,624 Stock-based compensation expenses 18,195 566 — 18,761 Deferred financing costs amortization and other 5,371 4,803 — 10,174 Working capital and other changes: Change in accounts receivable (85 ) (88,509 ) 99,943 11,349 Change in inventory — 2,559 — 2,559 Change in prepaid expenses (135 ) 1,303 — 1,168 Change in other current assets — (240 ) — (240 ) Change in other assets 100 (248 ) — (148 ) Change in accounts payable, interest payable and accrued liabilities 70,285 (12,333 ) (99,943 ) (41,991 ) Change in other current liabilities — (6,000 ) — (6,000 ) Change in other liabilities — 17 — 17 Net cash provided by (used in) operating activities (23,899 ) 147,318 — 123,419 Cash flows from investing activities: Capital expenditures — (340,314 ) — (340,314 ) Proceeds from sale of properties — 12,333 — 12,333 Costs related to sale of properties — (310 ) — (310 ) Derivative settlements — 115,576 — 115,576 Advances from joint interest partners — 544 — 544 Net cash used in investing activities — (212,171 ) — (212,171 ) Cash flows from financing activities: Repurchase of senior unsecured notes (435,907 ) — — (435,907 ) Proceeds from issuance of senior unsecured convertible notes 300,000 — — 300,000 Proceeds from revolving credit facility — 835,000 — 835,000 Principal payments on revolving credit facility — (778,000 ) — (778,000 ) Deferred financing costs (7,880 ) (931 ) — (8,811 ) Proceeds from sale of common stock 182,791 — — 182,791 Purchases of treasury stock (2,275 ) — — (2,275 ) Investment in / capital contributions from subsidiaries (13,517 ) 13,517 — — Net cash provided by financing activities 23,212 69,586 — 92,798 Increase (decrease) in cash and cash equivalents (687 ) 4,733 — 4,046 Cash and cash equivalents at beginning of period 777 8,953 — 9,730 Cash and cash equivalents at end of period $ 90 $ 13,686 $ — $ 13,776 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2015 Parent/ Issuer Combined Guarantor Subsidiaries Intercompany Eliminations Consolidated (In thousands) Cash flows from operating activities: Net income (loss) $ (44,216 ) $ 28,269 $ (28,269 ) $ (44,216 ) Adjustments to reconcile net income (loss) to cash provided by operating activities: Equity in earnings of subsidiaries (28,269 ) — 28,269 — Depreciation, depletion and amortization — 361,430 — 361,430 Gain on sale of properties — (172 ) — (172 ) Impairment — 24,917 — 24,917 Deferred income taxes (51,792 ) 33,963 — (17,829 ) Derivative instruments — (111,285 ) — (111,285 ) Stock-based compensation expenses 19,276 353 — 19,629 Deferred financing costs amortization and other 3,401 4,067 — 7,468 Working capital and other changes: Change in accounts receivable (493 ) (22,000 ) 130,802 108,309 Change in inventory — 8,425 — 8,425 Change in prepaid expenses (120 ) 758 — 638 Change in other current assets — 5,529 — 5,529 Change in accounts payable, interest payable and accrued liabilities 105,536 (58,867 ) (130,802 ) (84,133 ) Change in other current liabilities — 1,655 — 1,655 Change in other liabilities — (28 ) — (28 ) Net cash provided by operating activities 3,323 277,014 — 280,337 Cash flows from investing activities: Capital expenditures — (740,633 ) — (740,633 ) Proceeds from sale of properties — 78 — 78 Derivative settlements — 291,436 — 291,436 Advances from joint interest partners — (1,239 ) — (1,239 ) Net cash used in investing activities — (450,358 ) — (450,358 ) Cash flows from financing activities: Proceeds from revolving credit facility — 618,000 — 618,000 Principal payments on revolving credit facility — (938,000 ) — (938,000 ) Deferred financing costs — (3,587 ) — (3,587 ) Proceeds from sale of common stock 462,833 — — 462,833 Purchases of treasury stock (2,771 ) — — (2,771 ) Investment in / capital contributions from subsidiaries (463,404 ) 463,404 — — Net cash provided by (used in) financing activities (3,342 ) 139,817 — 136,475 Decrease in cash and cash equivalents (19 ) (33,527 ) — (33,546 ) Cash and cash equivalents at beginning of period 776 45,035 — 45,811 Cash and cash equivalents at end of period $ 757 $ 11,508 $ — $ 12,265

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Crude oil inventory	$ 5,344	$ 6,152
Equipment and materials	3,169	4,920
Total inventory	$ 8,513	$ 11,072

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	Sep. 30, 2016	Dec. 31, 2015
Assets:
Total assets	$ 9,390	$ 156,215
Total liabilities	25,063
Money market funds [Member]
Assets:
Total assets	54	742
Commodity derivative instruments [Member]
Assets:
Total assets	9,336	155,473
Total liabilities	25,063
Level 1 [Member]
Assets:
Total assets	54	742
Total liabilities	0
Level 1 [Member] | Money market funds [Member]
Assets:
Total assets	54	742
Level 1 [Member] | Commodity derivative instruments [Member]
Assets:
Total assets	0	0
Total liabilities	0
Level 2 [Member]
Assets:
Total assets	9,336	155,473
Total liabilities	25,063
Level 2 [Member] | Money market funds [Member]
Assets:
Total assets	0	0
Level 2 [Member] | Commodity derivative instruments [Member]
Assets:
Total assets	9,336	155,473
Total liabilities	25,063
Level 3 [Member]
Assets:
Total assets	0	0
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
Total liabilities	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Sep. 15, 2016
Debt Instrument [Line Items]
Derivative credit risk valuation adjustment, derivative assets	$ 1,200,000		$ 1,200,000		$ 300,000
Long-term debt	2,125,573,000		2,125,573,000		2,302,584,000
Deferred financing costs	35,000,000		35,000,000
Asset retirement obligation, carrying value	37,829,000		37,829,000		35,812,000
Impairment	382,000	$ 80,000	3,967,000	$ 24,917,000
Proved Oil and Gas Properties [Member]
Debt Instrument [Line Items]
Impairment	0	0	0	0
Proved Oil and Gas Properties [Member] | Assets disposed of by sale [Member]
Debt Instrument [Line Items]
Impairment			3,600,000
Proved Oil and Gas Properties [Member] | Assets disposed of by sale [Member] | Operating Segments [Member] | Midstream Services [Member]
Debt Instrument [Line Items]
Impairment			2,400,000
Proved Oil and Gas Properties [Member] | Assets disposed of by sale [Member] | Operating Segments [Member] | Exploration and Production [Member]
Debt Instrument [Line Items]
Impairment			1,200,000
Proved Oil and Gas Properties [Member] | Assets held for sale [Member]
Debt Instrument [Line Items]
Impairment	0	0	3,600,000	0	9,400,000
Unproved Oil And Gas Properties [Member] | Expiring Lease 1 [Member]
Debt Instrument [Line Items]
Impairment	400,000	$ 100,000	400,000	24,900,000
Unproved Oil And Gas Properties [Member] | Expiring Lease 2 [Member]
Debt Instrument [Line Items]
Impairment	200,000		200,000	$ 16,400,000
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	2,018,000,000		2,018,000,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	195,000,000		195,000,000
2.625% senior convertible notes due September 15, 2023 [Member] | Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt instrument unamortized discount	92,877,000		92,877,000		$ 0	$ 93,200,000
Estimated fair value of debt						$ 206,800,000
Long-term Debt [Member] | Notes [Member] | Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term debt	2,053,000,000		2,053,000,000
Debt instrument unamortized discount	92,900,000		92,900,000
Deferred financing costs	$ 29,500,000		$ 29,500,000

Derivative Instruments - Schedu

Derivative Instruments - Schedule of Outstanding Commodity Derivative Instruments (Details) MMBTU in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)MBblsMMBTU$ / bbl
Oil [Member]
Derivative [Line Items]
Fair value asset (liability) | $	$ (15,727)
Oil [Member] | 2016 Swaps [Member]
Derivative [Line Items]
Total notional amount of oil (in MBbls) | MBbls	2,973
Average swap price (in dollars per barrel)	49.18
Fair value asset (liability) | $	$ 4,765
Oil [Member] | 2017 Swaps [Member]
Derivative [Line Items]
Total notional amount of oil (in MBbls) | MBbls	5,059
Average swap price (in dollars per barrel)	48.04
Fair value asset (liability) | $	$ (14,742)
Oil [Member] | 2017 Two Way Collars [Member]
Derivative [Line Items]
Total notional amount of oil (in MBbls) | MBbls	1,002
Average floor price (in dollars per barrel)	41.67
Average ceiling price (in dollars per barrel)	50.58
Fair value asset (liability) | $	$ (4,092)
Oil [Member] | 2017 Three Way Collars [Member]
Derivative [Line Items]
Total notional amount of oil (in MBbls) | MBbls	1,670
Average sub-floor price (in dollars per barrel)	30
Average floor price (in dollars per barrel)	45
Average ceiling price (in dollars per barrel)	60.11
Fair value asset (liability) | $	$ 241
Oil [Member] | 2018 Swaps [Member]
Derivative [Line Items]
Total notional amount of oil (in MBbls) | MBbls	522
Average swap price (in dollars per barrel)	50.07
Fair value asset (liability) | $	$ (1,349)
Oil [Member] | 2018 Two Way Collars [Member]
Derivative [Line Items]
Total notional amount of oil (in MBbls) | MBbls	93
Average floor price (in dollars per barrel)	41.67
Average ceiling price (in dollars per barrel)	50.58
Fair value asset (liability) | $	$ (471)
Oil [Member] | 2018 Three Way Collars [Member]
Derivative [Line Items]
Total notional amount of oil (in MBbls) | MBbls	155
Average sub-floor price (in dollars per barrel)	30
Average floor price (in dollars per barrel)	45
Average ceiling price (in dollars per barrel)	60.11
Fair value asset (liability) | $	$ (122)
Natural Gas [Member] | 2017 Swaps [Member]
Derivative [Line Items]
Total notional amount of natural gas (in Btu) | MMBTU	1,336
Average swap price (in dollars per barrel)	3.12
Fair value asset (liability) | $	$ 52
Natural Gas [Member] | 2018 Swaps [Member]
Derivative [Line Items]
Total notional amount of natural gas (in Btu) | MMBTU	124
Average swap price (in dollars per barrel)	3.12
Fair value asset (liability) | $	$ (9)

Derivative Instruments - Sche39

Derivative Instruments - Schedule of Location and Fair Value of Outstanding Commodity Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative instruments — current assets	$ 9,142	$ 139,697
Derivative instruments — non-current assets	194	15,776
Derivative instruments — current liabilities	(17,308)	0
Derivative instruments — non-current liabilities	(7,755)	0
Commodity derivative instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative instruments — current assets	9,142	139,697
Derivative instruments — non-current assets	194	15,776
Derivative instruments — current liabilities	(17,308)	0
Derivative instruments — non-current liabilities	(7,755)	0
Total derivative instruments	$ (15,727)	$ 155,473

Derivative Instruments - Realiz

Derivative Instruments - Realized and Unrealized Gains and Losses from Commodity Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net gain (loss) on derivative instruments	$ 20,847	$ 103,637	$ (55,624)	$ 111,285

Derivative Instruments - Summar

Derivative Instruments - Summary of Gross and Net Information about Commodity Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross Amounts of Recognized Assets	$ 23,713	$ 155,473
Derivative Assets, Gross Amounts Offset in the Balance Sheet	(14,377)	0
Net Amounts of Assets Presented in the Balance Sheet	9,336	155,473
Gross Amounts of Recognized Liabilities	39,440	0
Derivative Liabilities, Gross Amounts Offset in the Balance Sheet	(14,377)	0
Net Amounts of Liabilities Presented in the Balance Sheet	$ 25,063	$ 0

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Proved oil and gas properties	[1]	$ 5,813,928	$ 5,655,759
Less: accumulated depreciation, depletion, amortization and impairment		(1,764,979)	(1,428,427)
Proved oil and gas properties, net		4,048,949	4,227,332
Unproved oil and gas properties		624,854	628,642
Other property and equipment		580,171	443,265
Less: accumulated depreciation		(101,301)	(80,997)
Other property and equipment, net		478,870	362,268
Total property, plant and equipment, net		5,152,673	5,218,242
Asset retirement costs		$ 31,500	$ 30,700
[1]	Included in the Company’s proved oil and gas properties are estimates of future asset retirement costs of $31.5 million and $30.7 million at September 30, 2016 and December 31, 2015, respectively.

Divestiture (Details)

Divestiture (Details) - USD ($)	Apr. 01, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of properties				$ 12,333,000	$ 78,000
Impairment		$ 382,000	$ 80,000	3,967,000	24,917,000
Proved Oil and Gas Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment		0	0	0	0
Proved Oil and Gas Properties [Member] | Assets disposed of by sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of properties	$ 12,300,000
Amount of promissory note	$ 4,000,000
Interest rate of promissory note (as percent)	10.00%
Impairment				3,600,000
Proved Oil and Gas Properties [Member] | Assets held for sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment		$ 0	$ 0	$ 3,600,000	$ 0	$ 9,400,000

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 15, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total long-term debt	$ 2,125,573		$ 2,302,584
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	195,000		138,000
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Total long-term debt	2,052,950		2,200,000
Less: unamortized deferred financing costs on senior unsecured notes	(29,500)		(35,416)
Senior Unsecured Debt [Member] | 7.25% senior unsecured notes due February 1, 2019 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 54,275		400,000
Stated interest rate (as percent)	7.25%
Senior Unsecured Debt [Member] | 6.5% senior unsecured notes due November 1, 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 395,501		400,000
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]
Total long-term debt	$ 937,080		1,000,000
Stated interest rate (as percent)	6.875%
Senior Unsecured Debt [Member] | 6.875% senior unsecured notes due January 15, 2023 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 366,094		400,000
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]
Total long-term debt	$ 300,000		0
Less: unamortized debt discount on senior unsecured convertible notes	$ (92,877)	$ (93,200)	$ 0
Stated interest rate (as percent)	2.625%

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details)	Sep. 28, 2016USD ($)	Sep. 30, 2016USD ($)day$ / shares	Sep. 30, 2016USD ($)$ / shares	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)$ / shares	Sep. 30, 2015USD ($)	Sep. 15, 2016USD ($)	Feb. 23, 2016USD ($)	Feb. 22, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Repurchase of senior unsecured debt					$ 435,907,000	$ 0
Gain (loss) on extinguishment of debt			$ (13,793,000)	$ 0	$ 4,865,000	0
Ownership percentage, guarantors (as percent)					100.00%
Deferred financing costs		$ 35,000,000	35,000,000		$ 35,000,000
Interest Expense [Member]
Debt Instrument [Line Items]
Amortization of deferred financing costs			2,100,000	1,600,000	6,200,000	5,000,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility amount		2,500,000,000	2,500,000,000		2,500,000,000
Line of credit facility, current borrowing capacity								$ 1,150,000,000	$ 1,525,000,000
Line of credit facility, amount outstanding		195,000,000	195,000,000		195,000,000
Outstanding letters of credit		12,300,000	12,300,000		12,300,000
Line of credit facility, remaining borrowing capacity		$ 942,700,000	$ 942,700,000		$ 942,700,000
Weighted average interest rate (as percent)		2.00%	2.00%		2.00%					1.90%
Commitment fee percentage					0.375%
Write-off of deferred financing costs			$ 0	0	$ 1,800,000	500,000
Line of Credit [Member] | Revolving Credit Facility [Member] | Other Assets [Member]
Debt Instrument [Line Items]
Deferred financing costs		$ 5,500,000	5,500,000		5,500,000
Line of Credit [Member] | Revolving Credit Facility [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding		195,000,000	195,000,000		195,000,000
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Amount of debt extinguished	$ 362,400,000
Repurchase of senior unsecured debt	371,400,000				64,500,000
Debt issuance costs		$ 29,500,000	$ 29,500,000		$ 29,500,000					$ 35,416,000
Senior Unsecured Debt [Member] | Minimum [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)		6.50%	6.50%		6.50%
Senior Unsecured Debt [Member] | Maximum [Member]
Debt Instrument [Line Items]
Stated interest rate (as percent)		7.25%	7.25%		7.25%
Senior Unsecured Debt [Member] | Notes [Member]
Debt Instrument [Line Items]
Unsecured debt		$ 1,753,000,000	$ 1,753,000,000		$ 1,753,000,000
Senior Unsecured Debt [Member] | Notes [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Debt discount		92,900,000	92,900,000		92,900,000
Deferred financing costs		$ 29,500,000	$ 29,500,000		$ 29,500,000
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%	7.25%		7.25%
Debt redemption price (percent)					101.813%
Amount of debt extinguished	344,700,000				$ 1,000,000
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%	6.50%		6.50%
Amount of debt extinguished	2,200,000				$ 2,300,000
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%	6.875%		6.875%
Amount of debt extinguished	3,400,000				$ 59,500,000
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%		2.625%
Debt issued		$ 300,000,000	$ 300,000,000		$ 300,000,000
Proceeds from convertible Debt		$ 291,900,000
Debt conversion rate per $1000 principal (in shares per $1000)		76.3650
Debt conversion price (in dollars per share) | $ / shares		$ 13.10	$ 13.10		$ 13.10
Debt instrument effective interest rate (percent)		8.97%	8.97%		8.97%
Estimated fair value of debt							$ 206,800,000
Debt discount		$ 92,877,000	$ 92,877,000		$ 92,877,000		$ 93,200,000			$ 0
Senior Unsecured Debt [Member] | 2.625% senior convertible notes due September 15, 2023 [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Debt issuance costs		5,400,000	5,400,000		5,400,000
Senior Unsecured Debt [Member] | 2.625% senior convertible notes due September 15, 2023 [Member] | Additional Paid-in-Capital [Member]
Debt Instrument [Line Items]
Debt issuance costs		$ 2,400,000	$ 2,400,000		$ 2,400,000
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%	6.875%		6.875%
Amount of debt extinguished	$ 12,100,000				$ 21,800,000
Senior Unsecured Debt [Member] | Purchased Notes [Member]
Debt Instrument [Line Items]
Amount of debt extinguished					84,600,000
Gain (loss) on extinguishment of debt			$ (13,800,000)		4,900,000
Senior Unsecured Debt [Member] | Purchased Notes [Member] | Gain of Extinguishment of Debt [Member]
Debt Instrument [Line Items]
Write-off of deferred financing costs			$ 5,300,000	$ 0	$ 6,300,000	$ 0
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		30 days
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		5 days
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	9 Months Ended
	Sep. 30, 2016USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at December 31, 2015	$ 35,812
Liabilities incurred during period	465
Liabilities settled during period	(444)	[1]
Accretion expense during period	1,425	[2]
Revisions to estimates	571
Balance at September 30, 2016	$ 37,829
[1]	Liabilities settled during the nine months ended September 30, 2016 included ARO related to the sold properties (see Note 7 – Divestiture).
[2]	Included in depreciation, depletion and amortization on the Company’s Condensed Consolidated Statement of Operations.

Asset Retirement Obligations 47

Asset Retirement Obligations - Additional Information (Details) $ in Millions	Sep. 30, 2016USD ($)
Asset Retirement Obligation Disclosure [Abstract]
Total asset retirement obligations, current portion	$ 0.7

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Effective tax rate (as percent)	33.00%	43.00%	34.00%	28.70%
Montana Net Operating Losses [Member]
Valuation Allowance [Line Items]
Valuation allowance increase, deferred tax asset			$ 0.8
Federal Charitable Contribution Carryovers [Member]
Valuation Allowance [Line Items]
Valuation allowance increase, deferred tax asset			$ 0.6

Common Stock (Details)

Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 02, 2016	Sep. 30, 2016	Sep. 30, 2015
Class of Stock [Line Items]
Shares issued, price per share (in usd per share)	$ 4.685
Net proceeds from offering		$ 182,791	$ 462,833
Common Stock [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares)		39,100,000
Net proceeds from offering		$ 400
Additional Paid-in-Capital [Member]
Class of Stock [Line Items]
Net proceeds from offering		$ 182,400
Common Stock [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares)	39,100,000
Common Stock [Member] | Over-Allotment Option [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares)	5,100,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)shares	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)day$ / sharesshares	Sep. 30, 2015USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expenses | $			$ 18,761	$ 19,629
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Stock granted (in shares) | shares			3,393,900
Granted, weighted average grant date fair value per unit (in usd per share) | $ / shares			$ 5.61
Stock-based compensation expenses | $	$ 4,800	$ 5,000	$ 15,500	16,800
Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual forfeiture rate (as a percent)			0.00%
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual forfeiture rate (as a percent)			20.00%
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock granted (in shares) | shares			910,000
Granted, weighted average grant date fair value per unit (in usd per share) | $ / shares			$ 3
Stock-based compensation expenses | $	$ 1,000	$ 1,000	$ 3,200	$ 2,900
Right to received shares of common stock (in shares) | shares	1		1
Number of trading days | day			30
Expected percentage earned (as a percent)	69.00%		69.00%
Performance Share Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual forfeiture rate (as a percent)			3.30%
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]
Annual forfeiture rate (as a percent)			4.60%
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]	9 Months Ended
	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forecast period (years)	4 years
Risk-free interest rate (as percent)	1.25%
Oasis stock price volatility (as percent)	59.38%

Earnings (Loss) Per Share - Sch

Earnings (Loss) Per Share - Schedule of Weighted-Average Number of Shares Outstanding (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding (in shares)	177,120,000	137,014,000	172,360,000	127,827,000
Dilution effect of stock awards at end of period (in shares)	0	0	0	0
Diluted weighted average common shares outstanding (in shares)	177,120,000	137,014,000	172,360,000	127,827,000
Anti-dilutive stock-based compensation awards (in shares)	5,139,848	2,787,054	4,935,353	2,939,368

Business Segment Information -

Business Segment Information - Additional Information (Details)	9 Months Ended
	Sep. 30, 2016Segment
Segment Reporting [Abstract]
Number of current operating units	3

Business Segment Information 54

Business Segment Information - Summarized Financial Information of Segments (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenues		$ 177,311	$ 197,235	$ 486,674	$ 607,668
Operating income (loss)		(25,702)	(19,926)	(129,131)	(60,998)
Other income (expense)		(24,931)	67,373	(156,015)	(1,047)
Income (loss) before income taxes		(50,633)	47,447	(285,146)	(62,045)
Property, plant and equipment, net		5,152,673		5,152,673		$ 5,218,242
Total assets		5,398,261		5,398,261		5,649,375
Assets held for sale		0		0		26,728
Exploration and Production [Member]
Segment Reporting Information [Line Items]
Total revenues		158,183	175,270	434,835	563,239
Well Services [Member]
Segment Reporting Information [Line Items]
Total revenues		22,459	48,935	74,482	158,528
Midstream Services [Member]
Segment Reporting Information [Line Items]
Total revenues		29,277	29,812	88,030	76,115
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues		177,311	197,235	486,674	607,668
Operating income (loss)		(25,702)	(19,926)	(129,131)	(60,998)
Other income (expense)		(24,931)	67,373	(156,015)	(1,047)
Income (loss) before income taxes		(50,633)	47,447	(285,146)	(62,045)
Property, plant and equipment, net		5,152,673		5,152,673		5,218,242
Total assets	[1]	5,398,261		5,398,261		5,649,375	[2]
Operating Segments [Member] | Exploration and Production [Member]
Segment Reporting Information [Line Items]
Total revenues		158,183	175,270	434,835	563,239
Operating income (loss)		(41,857)	(38,289)	(175,480)	(103,065)
Other income (expense)		(24,476)	67,359	(155,595)	(1,037)
Income (loss) before income taxes		(66,333)	29,070	(331,075)	(104,102)
Property, plant and equipment, net		4,883,137		4,883,137		5,057,311
Total assets	[1]	5,120,567		5,120,567		5,478,439	[2]
Assets held for sale						26,700
Operating Segments [Member] | Well Services [Member]
Segment Reporting Information [Line Items]
Total revenues		10,641	15,381	29,459	27,308
Operating income (loss)		1,572	10,936	3,420	29,554
Other income (expense)		5	14	42	34
Income (loss) before income taxes		1,577	10,950	3,462	29,588
Property, plant and equipment, net		50,477		50,477		61,402
Total assets	[1]	53,235		53,235		66,952	[2]
Operating Segments [Member] | Midstream Services [Member]
Segment Reporting Information [Line Items]
Total revenues		8,487	6,584	22,380	17,121
Operating income (loss)		16,525	18,828	49,724	44,083
Other income (expense)		(460)	0	(462)	(44)
Income (loss) before income taxes		16,065	18,828	49,262	44,039
Property, plant and equipment, net		391,282		391,282		264,956
Total assets	[1]	396,682		396,682		269,411	[2]
Segment Reconciling Items [Member] | Exploration and Production [Member]
Segment Reporting Information [Line Items]
Total revenues		0	0	0	0
Segment Reconciling Items [Member] | Well Services [Member]
Segment Reporting Information [Line Items]
Total revenues		11,818	33,554	45,023	131,220
Segment Reconciling Items [Member] | Midstream Services [Member]
Segment Reporting Information [Line Items]
Total revenues		20,790	23,228	65,650	58,994
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues		(32,608)	(56,782)	(110,673)	(190,214)
Operating income (loss)		(1,942)	(11,401)	(6,795)	(31,570)
Other income (expense)		0	0	0	0
Income (loss) before income taxes		(1,942)	$ (11,401)	(6,795)	$ (31,570)
Property, plant and equipment, net		(172,223)		(172,223)		(165,427)
Total assets	[1]	$ (172,223)		$ (172,223)		$ (165,427)	[2]
[1]	Intercompany receivables (payables) for all segments were reclassified to capital contributions from (distributions to) parent and not included in total assets.
[2]	At December 31, 2015, total assets included assets held for sale of $26.7 million in the exploration and production segment related to the assets sold as of April 1, 2016 (see Note 7 – Divestiture).

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - 9 months ended Sep. 30, 2016 $ in Millions	USD ($)	MBbls	MMcf
Commitments And Contingencies [Line Items]
Total rental commitments under leases	$ 20.7
Future obligations under purchase agreements	$ 38.4
Williston Basin Project [Member] | Long Term Commitments [Member]
Commitments And Contingencies [Line Items]
Maximum commitment term (less than)	10 years
Future obligations under supply agreements	$ 443.1
Williston Basin Project [Member] | Crude oil [Member] | Long Term Commitments [Member]
Commitments And Contingencies [Line Items]
Minimum quantity of delivery (in MBbl of crude oil, MBbl of natural gas liquids, and MMcf of natural gas) | MBbls		43,800
Williston Basin Project [Member] | Natural Gas [Member] | Long Term Commitments [Member]
Commitments And Contingencies [Line Items]
Minimum quantity of delivery (in MBbl of crude oil, MBbl of natural gas liquids, and MMcf of natural gas)		23,000	216,700

Condensed Consolidating Finan56

Condensed Consolidating Financial Information - Additional Information (Details)	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Ownership percentage, guarantors (as percent)	100.00%

Condensed Consolidating Finan57

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 13,776	$ 9,730	$ 12,265	$ 45,811
Accounts receivable – oil and gas revenues	103,128	96,495
Accounts receivable – joint interest and other	77,903	100,914
Accounts receivable – affiliates	0	0
Inventory	8,513	11,072
Prepaid expenses	6,093	7,328
Derivative instruments	9,142	139,697
Other current assets	4,290	50
Total current assets	222,845	365,286
Property, plant and equipment
Oil and gas properties (successful efforts method)	6,438,782	6,284,401
Other property and equipment	580,171	443,265
Less: accumulated depreciation, depletion, amortization and impairment	(1,866,280)	(1,509,424)
Total property, plant and equipment, net	5,152,673	5,218,242
Assets held for sale	0	26,728
Investments in and advances to subsidiaries	0	0
Derivative instruments	194	15,776
Deferred income taxes	0	0
Other assets	22,549	23,343
Total assets	5,398,261	5,649,375
Current liabilities
Accounts payable	7,929	9,983
Accounts payable – affiliates	0	0
Revenues and production taxes payable	141,991	132,356
Accrued liabilities	98,926	167,669
Accrued interest payable	19,798	49,413
Derivative instruments	17,308	0
Advances from joint interest partners	5,191	4,647
Other current liabilities		6,500
Total current liabilities	291,143	370,568
Long-term debt	2,125,573	2,302,584
Deferred income taxes	546,202	608,155
Asset retirement obligations	37,092	35,338
Liabilities held for sale	0	10,228
Derivative instruments	7,755	0
Other liabilities	2,992	3,160
Total liabilities	3,010,757	3,330,033
Stockholders’ equity
Capital contributions from affiliates	0	0
Common stock, $0.01 par value: 450,000,000 shares authorized,181,200,581 shares issued and 180,399,060 shares outstanding at June 30, 2016; 300,000,000 shares authorized,139,583,990 shares issued and 139,076,064 shares outstanding at December 31, 2015	1,779	1,376
Treasury stock, at cost: 801,521 and 507,926 shares at June 30, 2016 and December 31, 2015, respectively	(15,895)	(13,620)
Additional paid-in capital	1,755,427	1,497,065
Retained earnings	646,193	834,521
Total stockholders’ equity	2,387,504	2,319,342
Total liabilities and stockholders’ equity	5,398,261	5,649,375
Intercompany Eliminations [Member]
Current assets
Cash and cash equivalents	0	0	0	0
Accounts receivable – oil and gas revenues	0	0
Accounts receivable – joint interest and other	0	0
Accounts receivable – affiliates	(348,679)	(248,736)
Inventory	0	0
Prepaid expenses	0	0
Derivative instruments	0	0
Other current assets	0	0
Total current assets	(348,679)	(248,736)
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
Assets held for sale		0
Investments in and advances to subsidiaries	(4,478,149)	(4,573,172)
Derivative instruments	0	0
Deferred income taxes	(205,200)	(205,174)
Other assets	0	0
Total assets	(5,032,028)	(5,027,082)
Current liabilities
Accounts payable	0	0
Accounts payable – affiliates	(348,679)	(248,736)
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	0
Total current liabilities	(348,679)	(248,736)
Long-term debt	0	0
Deferred income taxes	(205,200)	(205,174)
Asset retirement obligations	0	0
Liabilities held for sale		0
Derivative instruments	0
Other liabilities	0	0
Total liabilities	(553,879)	(453,910)
Stockholders’ equity
Capital contributions from affiliates	(3,385,326)	(3,369,895)
Common stock, $0.01 par value: 450,000,000 shares authorized,181,200,581 shares issued and 180,399,060 shares outstanding at June 30, 2016; 300,000,000 shares authorized,139,583,990 shares issued and 139,076,064 shares outstanding at December 31, 2015	0	0
Treasury stock, at cost: 801,521 and 507,926 shares at June 30, 2016 and December 31, 2015, respectively	0	0
Additional paid-in capital	(8,743)	(8,743)
Retained earnings	(1,084,080)	(1,194,534)
Total stockholders’ equity	(4,478,149)	(4,573,172)
Total liabilities and stockholders’ equity	(5,032,028)	(5,027,082)
Parent/Issuer [Member]
Current assets
Cash and cash equivalents	90	777	757	776
Accounts receivable – oil and gas revenues	0	0
Accounts receivable – joint interest and other	0	15
Accounts receivable – affiliates	1,348	1,248
Inventory	0	0
Prepaid expenses	413	278
Derivative instruments	0	0
Other current assets	0	0
Total current assets	1,851	2,318
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
Assets held for sale		0
Investments in and advances to subsidiaries	4,478,149	4,573,172
Derivative instruments	0	0
Deferred income taxes	205,200	205,174
Other assets	0	100
Total assets	4,685,200	4,780,764
Current liabilities
Accounts payable	0	0
Accounts payable – affiliates	347,331	247,488
Revenues and production taxes payable	0	0
Accrued liabilities	27	10
Accrued interest payable	19,765	49,340
Derivative instruments	0
Advances from joint interest partners	0	0
Other current liabilities	0	0
Total current liabilities	367,123	296,838
Long-term debt	1,930,573	2,164,584
Deferred income taxes	0	0
Asset retirement obligations	0	0
Liabilities held for sale		0
Derivative instruments	0
Other liabilities	0	0
Total liabilities	2,297,696	2,461,422
Stockholders’ equity
Capital contributions from affiliates	0	0
Common stock, $0.01 par value: 450,000,000 shares authorized,181,200,581 shares issued and 180,399,060 shares outstanding at June 30, 2016; 300,000,000 shares authorized,139,583,990 shares issued and 139,076,064 shares outstanding at December 31, 2015	1,779	1,376
Treasury stock, at cost: 801,521 and 507,926 shares at June 30, 2016 and December 31, 2015, respectively	(15,895)	(13,620)
Additional paid-in capital	1,755,427	1,497,065
Retained earnings	646,193	834,521
Total stockholders’ equity	2,387,504	2,319,342
Total liabilities and stockholders’ equity	4,685,200	4,780,764
Combined Guarantor Subsidiaries [Member]
Current assets
Cash and cash equivalents	13,686	8,953	$ 11,508	$ 45,035
Accounts receivable – oil and gas revenues	103,128	96,495
Accounts receivable – joint interest and other	77,903	100,899
Accounts receivable – affiliates	347,331	247,488
Inventory	8,513	11,072
Prepaid expenses	5,680	7,050
Derivative instruments	9,142	139,697
Other current assets	4,290	50
Total current assets	569,673	611,704
Property, plant and equipment
Oil and gas properties (successful efforts method)	6,438,782	6,284,401
Other property and equipment	580,171	443,265
Less: accumulated depreciation, depletion, amortization and impairment	(1,866,280)	(1,509,424)
Total property, plant and equipment, net	5,152,673	5,218,242
Assets held for sale		26,728
Investments in and advances to subsidiaries	0	0
Derivative instruments	194	15,776
Deferred income taxes	0	0
Other assets	22,549	23,243
Total assets	5,745,089	5,895,693
Current liabilities
Accounts payable	7,929	9,983
Accounts payable – affiliates	1,348	1,248
Revenues and production taxes payable	141,991	132,356
Accrued liabilities	98,899	167,659
Accrued interest payable	33	73
Derivative instruments	17,308
Advances from joint interest partners	5,191	4,647
Other current liabilities	0	6,500
Total current liabilities	272,699	322,466
Long-term debt	195,000	138,000
Deferred income taxes	751,402	813,329
Asset retirement obligations	37,092	35,338
Liabilities held for sale		10,228
Derivative instruments	7,755
Other liabilities	2,992	3,160
Total liabilities	1,266,940	1,322,521
Stockholders’ equity
Capital contributions from affiliates	3,385,326	3,369,895
Common stock, $0.01 par value: 450,000,000 shares authorized,181,200,581 shares issued and 180,399,060 shares outstanding at June 30, 2016; 300,000,000 shares authorized,139,583,990 shares issued and 139,076,064 shares outstanding at December 31, 2015	0	0
Treasury stock, at cost: 801,521 and 507,926 shares at June 30, 2016 and December 31, 2015, respectively	0	0
Additional paid-in capital	8,743	8,743
Retained earnings	1,084,080	1,194,534
Total stockholders’ equity	4,478,149	4,573,172
Total liabilities and stockholders’ equity	$ 5,745,089	$ 5,895,693

Condensed Consolidating Finan58

Condensed Consolidating Financial Information Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Balance Sheet - Additional Information (Details) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
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	300,000,000
Common stock, shares issued (in shares)	182,038,164	139,583,990
Common stock, shares outstanding (in shares)	181,186,070	139,076,064
Treasury stock, shares (in shares)	852,094	507,926

Condensed Consolidating Finan59

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues
Oil and gas revenues	$ 158,183	$ 175,270	$ 434,835	$ 563,239
Well services and midstream revenues	19,128	21,965	51,839	44,429
Total revenues	177,311	197,235	486,674	607,668
Operating expenses
Lease operating expenses	35,696	35,670	98,283	112,556
Well services and midstream operating expenses	8,165	10,023	21,429	19,370
Marketing, transportation and gathering expenses	8,856	8,465	23,899	23,313
Production taxes	14,638	16,676	39,758	53,915
Depreciation, depletion and amortization	111,948	123,734	356,885	361,430
Exploration expenses	489	327	1,192	2,252
Rig termination	0	0	0	3,895
Impairment	382	80	3,967	24,917
General and administrative expenses	22,845	22,358	69,087	67,190
Total operating expenses	203,019	217,333	614,500	668,838
Gain (loss) on sale of properties	6	172	(1,305)	172
Operating loss	(25,702)	(19,926)	(129,131)	(60,998)
Other income (expense)
Equity in loss of subsidiaries	0	0	0	0
Net gain (loss) on derivative instruments	20,847	103,637	(55,624)	111,285
Interest expense, net of capitalized interest	(31,726)	(36,513)	(105,444)	(112,702)
Gain (loss) on extinguishment of debt	(13,793)	0	4,865	0
Other income	(259)	249	188	370
Total other income (expense)	(24,931)	67,373	(156,015)	(1,047)
Income (loss) before income taxes	(50,633)	47,447	(285,146)	(62,045)
Income tax benefit (expense)	16,691	(20,392)	96,818	17,829
Net income (loss)	(33,942)	27,055	(188,328)	(44,216)
Intercompany Eliminations [Member]
Revenues
Oil and gas revenues	0	0	0	0
Well services and midstream revenues	0	0	0	0
Total revenues	0	0	0	0
Operating expenses
Lease operating expenses	0	0	0	0
Well services and midstream operating expenses	0	0	0	0
Marketing, transportation and gathering expenses	0	0	0	0
Production taxes	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Exploration expenses	0	0	0	0
Rig termination				0
Impairment	0	0	0	0
General and administrative expenses	0	0	0	0
Total operating expenses	0	0	0	0
Gain (loss) on sale of properties	0	0	0	0
Operating loss	0	0	0	0
Other income (expense)
Equity in loss of subsidiaries	1,140	(49,899)	110,454	(28,269)
Net gain (loss) on derivative instruments	0	0	0	0
Interest expense, net of capitalized interest	0	0	0	0
Gain (loss) on extinguishment of debt	0		0
Other income	0	0	0	0
Total other income (expense)	1,140	(49,899)	110,454	(28,269)
Income (loss) before income taxes	1,140	(49,899)	110,454	(28,269)
Income tax benefit (expense)	0	0	0	0
Net income (loss)	1,140	(49,899)	110,454	(28,269)
Parent/Issuer [Member]
Revenues
Oil and gas revenues	0	0	0	0
Well services and midstream revenues	0	0	0	0
Total revenues	0	0	0	0
Operating expenses
Lease operating expenses	0	0	0	0
Well services and midstream operating expenses	0	0	0	0
Marketing, transportation and gathering expenses	0	0	0	0
Production taxes	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Exploration expenses	0	0	0	0
Rig termination				0
Impairment	0	0	0	0
General and administrative expenses	5,930	5,903	19,776	20,847
Total operating expenses	5,930	5,903	19,776	20,847
Gain (loss) on sale of properties	0	0	0	0
Operating loss	(5,930)	(5,903)	(19,776)	(20,847)
Other income (expense)
Equity in loss of subsidiaries	(1,140)	49,899	(110,454)	28,269
Net gain (loss) on derivative instruments	0	0	0	0
Interest expense, net of capitalized interest	(29,876)	(34,020)	(97,898)	(103,435)
Gain (loss) on extinguishment of debt	(13,793)		4,865
Other income	1	1	44	5
Total other income (expense)	(44,808)	15,880	(203,443)	(75,161)
Income (loss) before income taxes	(50,738)	9,977	(223,219)	(96,008)
Income tax benefit (expense)	16,796	17,078	34,891	51,792
Net income (loss)	(33,942)	27,055	(188,328)	(44,216)
Combined Guarantor Subsidiaries [Member]
Revenues
Oil and gas revenues	158,183	175,270	434,835	563,239
Well services and midstream revenues	19,128	21,965	51,839	44,429
Total revenues	177,311	197,235	486,674	607,668
Operating expenses
Lease operating expenses	35,696	35,670	98,283	112,556
Well services and midstream operating expenses	8,165	10,023	21,429	19,370
Marketing, transportation and gathering expenses	8,856	8,465	23,899	23,313
Production taxes	14,638	16,676	39,758	53,915
Depreciation, depletion and amortization	111,948	123,734	356,885	361,430
Exploration expenses	489	327	1,192	2,252
Rig termination				3,895
Impairment	382	80	3,967	24,917
General and administrative expenses	16,915	16,455	49,311	46,343
Total operating expenses	197,089	211,430	594,724	647,991
Gain (loss) on sale of properties	6	172	(1,305)	172
Operating loss	(19,772)	(14,023)	(109,355)	(40,151)
Other income (expense)
Equity in loss of subsidiaries	0	0	0	0
Net gain (loss) on derivative instruments	20,847	103,637	(55,624)	111,285
Interest expense, net of capitalized interest	(1,850)	(2,493)	(7,546)	(9,267)
Gain (loss) on extinguishment of debt	0		0
Other income	(260)	248	144	365
Total other income (expense)	18,737	101,392	(63,026)	102,383
Income (loss) before income taxes	(1,035)	87,369	(172,381)	62,232
Income tax benefit (expense)	(105)	(37,470)	61,927	(33,963)
Net income (loss)	$ (1,140)	$ 49,899	$ (110,454)	$ 28,269

Condensed Consolidating Finan60

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ (33,942)	$ 27,055	$ (188,328)	$ (44,216)
Adjustments to reconcile net loss to cash provided by (used in) operating activities:
Equity in loss of subsidiaries	0	0	0	0
Depreciation, depletion and amortization	111,948	123,734	356,885	361,430
Gain on extinguishment of debt	13,793	0	(4,865)	0
Gain (loss) on sale of properties			1,305	(172)
Impairment	382	80	3,967	24,917
Deferred income taxes			(96,818)	(17,829)
Derivative instruments	(20,847)	(103,637)	55,624	(111,285)
Stock-based compensation expenses			18,761	19,629
Deferred financing costs amortization and other			10,174	7,468
Working capital and other changes:
Change in accounts receivable			11,349	108,309
Change in inventory			2,559	8,425
Change in prepaid expenses			1,168	638
Change in other current assets			(240)	5,529
Change in other assets			(148)	0
Change in accounts payable, interest payable and accrued liabilities			(41,991)	(84,133)
Change in other current liabilities			(6,000)	1,655
Change in other liabilities			17	(28)
Net cash provided by operating activities			123,419	280,337
Cash flows from investing activities:
Capital expenditures			(340,314)	(740,633)
Proceeds from sale of properties			12,333	78
Proceeds from sale of properties				78
Costs related to sale of properties			(310)	0
Derivative settlements			115,576	291,436
Advances from joint interest partners			544	(1,239)
Net cash used in investing activities			(212,171)	(450,358)
Cash flows from financing activities:
Repurchase of senior unsecured notes			(435,907)	0
Proceeds from issuance of senior unsecured convertible notes			300,000	0
Proceeds from revolving credit facility			835,000	618,000
Principal payments on revolving credit facility			(778,000)	(938,000)
Deferred financing costs			(8,811)	(3,587)
Proceeds from sale of common stock			182,791	462,833
Purchases of treasury stock			(2,275)	(2,771)
Investment in / capital contributions from subsidiaries			0	0
Net cash provided by financing activities			92,798	136,475
Increase (decrease) in cash and cash equivalents			4,046	(33,546)
Beginning of period			9,730	45,811	$ 45,811
End of period	13,776	12,265	13,776	12,265	9,730
Intercompany Eliminations [Member]
Cash flows from operating activities:
Net income (loss)	1,140	(49,899)	110,454	(28,269)
Adjustments to reconcile net loss to cash provided by (used in) operating activities:
Equity in loss of subsidiaries	(1,140)	49,899	(110,454)	28,269
Depreciation, depletion and amortization	0	0	0	0
Gain on extinguishment of debt	0		0
Gain (loss) on sale of properties			0	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			99,943	130,802
Change in inventory			0	0
Change in prepaid expenses			0	0
Change in other current assets			0	0
Change in other assets			0
Change in accounts payable, interest payable and accrued liabilities			(99,943)	(130,802)
Change in other current liabilities			0	0
Change in other liabilities			0	0
Net cash provided by operating activities			0	0
Cash flows from investing activities:
Capital expenditures			0	0
Proceeds from sale of properties			0
Proceeds from sale of properties				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:
Repurchase of senior unsecured notes			0
Proceeds from issuance of senior unsecured convertible notes			0
Proceeds from revolving credit facility			0	0
Principal payments on revolving credit facility			0	0
Deferred financing costs			0	0
Proceeds from sale of common stock			0	0
Purchases of treasury stock			0	0
Investment in / capital contributions from subsidiaries			0	0
Net cash provided by financing activities			0	0
Increase (decrease) in cash and cash equivalents			0	0
Beginning of period			0	0	0
End of period	0	0	0	0	0
Parent/Issuer [Member]
Cash flows from operating activities:
Net income (loss)	(33,942)	27,055	(188,328)	(44,216)
Adjustments to reconcile net loss to cash provided by (used in) operating activities:
Equity in loss of subsidiaries	1,140	(49,899)	110,454	(28,269)
Depreciation, depletion and amortization	0	0	0	0
Gain on extinguishment of debt	13,793		(4,865)
Gain (loss) on sale of properties			0	0
Impairment	0	0	0	0
Deferred income taxes			(34,891)	(51,792)
Derivative instruments	0	0	0	0
Stock-based compensation expenses			18,195	19,276
Deferred financing costs amortization and other			5,371	3,401
Working capital and other changes:
Change in accounts receivable			(85)	(493)
Change in inventory			0	0
Change in prepaid expenses			(135)	(120)
Change in other current assets			0	0
Change in other assets			100
Change in accounts payable, interest payable and accrued liabilities			70,285	105,536
Change in other current liabilities			0	0
Change in other liabilities			0	0
Net cash provided by operating activities			(23,899)	3,323
Cash flows from investing activities:
Capital expenditures			0	0
Proceeds from sale of properties			0
Proceeds from sale of properties				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:
Repurchase of senior unsecured notes			(435,907)
Proceeds from issuance of senior unsecured convertible notes			300,000
Proceeds from revolving credit facility			0	0
Principal payments on revolving credit facility			0	0
Deferred financing costs			(7,880)	0
Proceeds from sale of common stock			182,791	462,833
Purchases of treasury stock			(2,275)	(2,771)
Investment in / capital contributions from subsidiaries			(13,517)	(463,404)
Net cash provided by financing activities			23,212	(3,342)
Increase (decrease) in cash and cash equivalents			(687)	(19)
Beginning of period			777	776	776
End of period	90	757	90	757	777
Combined Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net income (loss)	(1,140)	49,899	(110,454)	28,269
Adjustments to reconcile net loss to cash provided by (used in) operating activities:
Equity in loss of subsidiaries	0	0	0	0
Depreciation, depletion and amortization	111,948	123,734	356,885	361,430
Gain on extinguishment of debt	0		0
Gain (loss) on sale of properties			1,305	(172)
Impairment	382	80	3,967	24,917
Deferred income taxes			(61,927)	33,963
Derivative instruments	(20,847)	(103,637)	55,624	(111,285)
Stock-based compensation expenses			566	353
Deferred financing costs amortization and other			4,803	4,067
Working capital and other changes:
Change in accounts receivable			(88,509)	(22,000)
Change in inventory			2,559	8,425
Change in prepaid expenses			1,303	758
Change in other current assets			(240)	5,529
Change in other assets			(248)
Change in accounts payable, interest payable and accrued liabilities			(12,333)	(58,867)
Change in other current liabilities			(6,000)	1,655
Change in other liabilities			17	(28)
Net cash provided by operating activities			147,318	277,014
Cash flows from investing activities:
Capital expenditures			(340,314)	(740,633)
Proceeds from sale of properties			12,333
Proceeds from sale of properties				78
Costs related to sale of properties			(310)
Derivative settlements			115,576	291,436
Advances from joint interest partners			544	(1,239)
Net cash used in investing activities			(212,171)	(450,358)
Cash flows from financing activities:
Repurchase of senior unsecured notes			0
Proceeds from issuance of senior unsecured convertible notes			0
Proceeds from revolving credit facility			835,000	618,000
Principal payments on revolving credit facility			(778,000)	(938,000)
Deferred financing costs			(931)	(3,587)
Proceeds from sale of common stock			0	0
Purchases of treasury stock			0	0
Investment in / capital contributions from subsidiaries			13,517	463,404
Net cash provided by financing activities			69,586	139,817
Increase (decrease) in cash and cash equivalents			4,733	(33,527)
Beginning of period			8,953	45,035	45,035
End of period	$ 13,686	$ 11,508	$ 13,686	$ 11,508	$ 8,953

Subsequent Events (Details)

Subsequent Events (Details) $ / shares in Units, a in Thousands

Oct. 21, 2016USD ($)$ / sharesshares

Oct. 17, 2016a

Dec. 01, 2016USD ($)

Sep. 30, 2016USD ($)

Sep. 30, 2015USD ($)

Oct. 31, 2016MMBTU

Oct. 31, 2016MBbls

Oct. 31, 2016$ / bbl

Oct. 31, 2016$ / MMBTU

Oct. 14, 2016USD ($)

Feb. 23, 2016USD ($)

Feb. 22, 2016USD ($)

Feb. 02, 2016$ / shares

Subsequent Event [Line Items]

Shares issued, price per share (in usd per share) | $ / shares

$ 4.685

Net proceeds from offering

$ 182,791,000

$ 462,833,000

Revolving Credit Facility [Member] | Line of Credit [Member]

Subsequent Event [Line Items]

Line of credit facility, current borrowing capacity

$ 1,150,000,000

$ 1,525,000,000

Subsequent Event [Member] | Public Offering [Member]

Subsequent Event [Line Items]

Issuance of common stock (in shares) | shares

55,200,000

Shares issued, price per share (in usd per share) | $ / shares

$ 10.80

Net proceeds from offering

$ 584,000,000

Subsequent Event [Member] | Over-Allotment Option [Member]

Subsequent Event [Line Items]

Issuance of common stock (in shares) | shares

7,200,000

Subsequent Event [Member] | Williston Basin Acquisition [Member]

Subsequent Event [Line Items]

Acres acquired | a

55

Subsequent Event [Member] | Revolving Credit Facility [Member] | Line of Credit [Member]

Subsequent Event [Line Items]

Line of credit facility, current borrowing capacity

$ 1,150,000,000

Subsequent Event [Member] | Commodity derivative instruments [Member] | Commodity Contract Maturing in 2017 [Member]

Subsequent Event [Line Items]

Total notional amount

668,000

2,338

Subsequent Event [Member] | Commodity derivative instruments [Member] | Commodity Contract Maturing in 2018 [Member]

Subsequent Event [Line Items]

Total notional amount

62,000

1,219

Subsequent Event [Member] | Commodity derivative instruments [Member] | Commodity Contract Maturing in 2019 [Member]

Subsequent Event [Line Items]

Total notional amount | MBbls

93

Subsequent Event [Member] | Crude oil [Member] | Commodity derivative instruments [Member]

Subsequent Event [Line Items]

Weighted average floor price (in dollars per barrel) | $ / bbl

51.73

Subsequent Event [Member] | Natural Gas [Member] | Commodity derivative instruments [Member]

Subsequent Event [Line Items]

Weighted average floor price (in dollars per barrel) | $ / MMBTU

3.38

Scenario, Forecast [Member] | Williston Basin Acquisition [Member]

Subsequent Event [Line Items]

Consideration to be paid for Purchase Agreement

$ 785,000,000