Gulfport Energy (GPOR) 10-Q 9 May 17 2017 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2017	May 01, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Entity Registrant Name	GULFPORT ENERGY CORP
Entity Central Index Key	874,499
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2,017
Entity Filer Category	Large Accelerated Filer
Document Fiscal Period Focus	Q1
Entity Common Stock, Shares Outstanding		182,835,801

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 102,485	$ 1,275,875
Restricted cash	0	185,000
Accounts receivable—oil and gas	158,154	136,761
Accounts receivable—related parties	39	16
Prepaid expenses and other current assets	16,005	7,639
Short-term derivative instruments	18,925	3,488
Total current assets	295,608	1,608,779
Property and equipment:
Oil and natural gas properties, full-cost accounting, $3,073,448 and $1,580,305 excluded from amortization in 2017 and 2016, respectively	8,146,321	6,071,920
Other property and equipment	75,107	68,986
Accumulated depletion, depreciation, amortization and impairment	(3,855,629)	(3,789,780)
Property and equipment, net	4,365,799	2,351,126
Other assets:
Equity investments	251,370	243,920
Long-term derivative instruments	23,515	5,696
Deferred tax asset	4,692	4,692
Other assets	12,945	8,932
Total other assets	292,522	263,240
Total assets	4,953,929	4,223,145
Current liabilities:
Accounts payable and accrued liabilities	406,139	265,124
Asset retirement obligation—current	195	195
Short-term derivative instruments	67,179	119,219
Current maturities of long-term debt	452	276
Total current liabilities	473,965	384,814
Long-term derivative instrument	5,259	26,759
Asset retirement obligation—long-term	41,142	34,081
Long-term debt, net of current maturities	1,631,809	1,593,599
Total liabilities	2,152,175	2,039,253
Commitments and contingencies (Note 9)
Preferred stock, $.01 par value; 5,000,000 authorized, 30,000 authorized as redeemable 12% cumulative preferred stock, Series A; 0 issued and outstanding	0	0
Stockholders’ equity:
Common stock - $.01 par value, 200,000,000 authorized, 182,835,801 issued and outstanding at March 31, 2017 and 158,829,816 at December 31, 2016	1,828	1,588
Paid-in capital	4,408,236	3,946,442
Accumulated other comprehensive loss	(51,685)	(53,058)
Retained deficit	(1,556,625)	(1,711,080)
Total stockholders’ equity	2,801,754	2,183,892
Total liabilities and stockholders’ equity	$ 4,953,929	$ 4,223,145

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Capitalized costs of oil and natural gas properties excluded from amortization	$ 3,073,448	$ 1,580,305
Preferred stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (shares)	5,000,000	5,000,000
Preferred stock dividend rate, percent	12.00%	12.00%
Temporary equity, shares authorized (shares)	30,000	30,000
Preferred stock Series A, issued (shares)	0	0
Preferred stock Series A, outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	200,000,000	200,000,000
Common stock, shares, issued (shares)	182,835,801	158,829,816
Common stock, shares, outstanding (shares)	182,835,801	158,829,816

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Gas sales	$ 177,837	$ 74,094
Oil and condensate sales	24,411	15,839
Natural gas liquid sales	31,179	9,293
Net gain on gas, oil, and NGL derivatives	99,577	57,735
Total revenues	333,004	156,961
Costs and expenses:
Lease operating expenses	19,303	16,657
Production taxes	3,906	3,111
Midstream gathering and processing	47,941	37,652
Depreciation, depletion and amortization	65,991	65,477
Impairment of oil and gas properties	0	218,991
General and administrative	12,600	10,620
Accretion expense	282	247
Acquisition expense	1,298	0
Total costs and expenses	151,321	352,755
INCOME (LOSS) FROM OPERATIONS	181,683	(195,794)
OTHER (INCOME) EXPENSE:
Interest expense	23,479	16,023
Interest income	(842)	(94)
(Income) loss from equity method investments	4,907	30,737
Other income	(316)	(2)
Total other (income) expense	27,228	46,664
INCOME (LOSS) BEFORE INCOME TAXES	154,455	(242,458)
INCOME TAX BENEFIT	0	(191)
NET INCOME (LOSS)	$ 154,455	$ (242,267)
NET INCOME (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ 0.91	$ (2.17)
Diluted (in dollars per share)	$ 0.91	$ (2.17)
Weighted average common shares outstanding - Basic (shares)	170,272,685	111,509,585
Weighted average common shares outstanding - Diluted (shares)	170,488,519	111,509,585

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 154,455	$ (242,267)
Foreign currency translation adjustment	1,373	9,058
Other comprehensive income	1,373	9,058
Comprehensive income (loss)	$ 155,828	$ (233,209)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Paid-in Capital	Accumulated Other Comprehensive Income (loss)	Retained Deficit
Beginning Balance (in shares) at Dec. 31, 2015		108,322,250
Beginning Balance at Dec. 31, 2015	$ 2,038,837	$ 1,082	$ 2,824,303	$ (55,177)	$ (731,371)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(242,267)				(242,267)
Other Comprehensive Income	9,058			9,058
Stock Compensation	3,341		3,341
Issuance of Common Stock in public offerings, net of related expenses (in shares)		16,905,000
Issuance of Common Stock in public offerings, net of related expenses	411,820	$ 169	411,651
Issuance of Restricted Stock (in shares)		100,310
Issuance of Restricted Stock	0	$ 1	(1)
Ending Balance (in shares) at Mar. 31, 2016		125,327,560
Ending Balance at Mar. 31, 2016	$ 2,220,789	$ 1,252	3,239,294	(46,119)	(973,638)
Beginning Balance (in shares) at Dec. 31, 2016	158,829,816	158,829,816
Beginning Balance at Dec. 31, 2016	$ 2,183,892	$ 1,588	3,946,442	(53,058)	(1,711,080)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	154,455				154,455
Other Comprehensive Income	1,373			1,373
Stock Compensation	2,553		2,553
Issuance of Common Stock for the Vitruvian Acquisition, net of related expenses (in shares)		23,852,117
Issuance of Common Stock for the Vitruvian Acquisition, net of related expenses	459,481	$ 239	459,242
Issuance of Restricted Stock (in shares)		153,868
Issuance of Restricted Stock	$ 0	$ 1	(1)
Ending Balance (in shares) at Mar. 31, 2017	182,835,801	182,835,801
Ending Balance at Mar. 31, 2017	$ 2,801,754	$ 1,828	$ 4,408,236	$ (51,685)	$ (1,556,625)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ 154,455,000	$ (242,267,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Accretion of discount—Asset Retirement Obligation	282,000	247,000
Depletion, depreciation and amortization	65,991,000	65,477,000
Impairment of oil and gas properties	0	218,991,000
Stock-based compensation expense	1,532,000	2,005,000
Loss from equity investments	5,150,000	30,896,000
Change in fair value of derivative instruments	(106,796,000)	7,685,000
Deferred income tax expense (benefit)	0	(191,000)
Amortization of loan commitment fees	1,088,000	946,000
Amortization of note discount and premium	0	(563,000)
Changes in operating assets and liabilities:
Increase in accounts receivable	(21,393,000)	(6,629,000)
Increase in accounts receivable—related party	(23,000)	(1,000)
(Increase) decrease in prepaid expenses	(8,366,000)	1,150,000
Increase in other assets	(4,013,000)	0
Increase in accounts payable, accrued liabilities and other	54,738,000	6,080,000
Settlement of asset retirement obligation	0	(52,000)
Net cash provided by operating activities	142,645,000	83,774,000
Cash flows from investing activities:
Additions to other property and equipment	(5,444,000)	(5,183,000)
Acquisition of oil and gas properties	(1,338,964,000)	0
Additions to oil and gas properties	(181,834,000)	(151,293,000)
Proceeds from sale of oil and gas properties	3,605,000	630,000
Funding of restricted cash	185,000,000	0
Contributions to equity method investments	(10,673,000)	(1,821,000)
Distributions from equity method investments	631,000	138,000
Net cash used in investing activities	(1,347,679,000)	(157,529,000)
Cash flows from financing activities:
Principal payments on borrowings	0	(1,685,000)
Borrowings on line of credit	40,000,000	0
Borrowings on term loan	2,698,000	5,041,000
Debt issuance costs and loan commitment fees	(5,733,000)	(116,000)
Proceeds from issuance of common stock, net of offering costs	(5,321,000)	411,918,000
Net cash provided by financing activities	31,644,000	415,158,000
Net (decrease) increase in cash and cash equivalents	(1,173,390,000)	341,403,000
Cash and cash equivalents at beginning of period	1,275,875,000	112,974,000
Cash and cash equivalents at end of period	102,485,000	454,377,000
Supplemental disclosure of cash flow information:
Interest payments	347,000	80,000
Income tax payments	0	0
Supplemental disclosure of non-cash transactions:
Capitalized stock based compensation	1,021,000	1,336,000
Asset retirement obligation capitalized	6,779,000	1,914,000
Interest capitalized	3,122,000	1,862,000
Foreign currency translation gain on equity method investments	$ 1,373,000	$ 9,058,000

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS Vitruvian Acquisition In December 2016, the Company, through its wholly-owned subsidiary Gulfport MidCon LLC (“Gulfport MidCon”) (formerly known as SCOOP Acquisition Company, LLC), entered into an agreement to acquire certain assets of Vitruvian II Woodford, LLC (“Vitruvian”), an unrelated third-party seller (the “Vitruvian Acquisition”). The assets included in the Vitruvian Acquisition include 46,400 net surface acres located in Grady, Stephens and Garvin Counties, Oklahoma. On February 17, 2017, the Company completed the Vitruvian Acquisition for a total initial purchase price of approximately $1.85 billion , consisting of $1.35 billion in cash, subject to certain adjustments, and approximately 23.9 million shares of the Company’s common stock (of which approximately 5.2 million shares were placed in an indemnity escrow). The cash portion of the purchase price was funded with the net proceeds from the December 2016 common stock and senior note offerings and cash on hand. Acquisition costs of $1.3 million were incurred during the three months ended March 31, 2017 related to the Vitruvian Acquisition. Allocation of Purchase Price The Vitruvian Acquisition qualified as a business combination for accounting purposes and, as such, the Company estimated the fair value of the acquired properties as of the February 17, 2017 acquisition date. The fair value of the assets acquired and liabilities assumed was estimated using assumptions that represent Level 3 inputs. See Note 11 for additional discussion of the measurement inputs. The Company estimated that the consideration paid in the Vitruvian Acquisition for these properties approximated the fair value that would be paid by a typical market participant. As a result, no goodwill or bargain purchase gain was recognized in conjunction with the purchase. The following table summarizes the consideration paid in the Vitruvian Acquisition to acquire the properties and the fair value amount of the assets acquired as of February 17, 2017. Both the consideration paid and the fair value assigned to the assets is preliminary and subject to adjustment. (In thousands) Consideration: Cash, net of purchase price adjustments $ 1,354,093 Fair value of Gulfport’s common stock issued 464,639 Total Consideration $ 1,818,732 Estimated Fair value of identifiable assets acquired and liabilities assumed: Oil and natural gas properties Proved properties $ 362,264 Unproved properties 1,462,957 Asset retirement obligations (6,489 ) Total fair value of net identifiable assets acquired $ 1,818,732 The equity consideration included in the initial purchase price was based on an equity offering price of $20.96 on December 15, 2016. The decrease in the price of Gulfport’s common stock from $20.96 on December 15, 2016 to $19.48 on February 17, 2017 resulted in a decrease to the fair value of the total consideration paid as compared to the initial purchase price of approximately $35.3 million , which resulted in a closing date fair value lower than the initial purchase price. Post-Acquisition Operating Results For the period from the acquisition date of February 17, 2017 to March 31, 2017 , the assets acquired in the Vitruvian Acquisition have contributed the following amounts of revenue to the Company’s consolidated statements of operations. The amount of net income contributed by the assets acquired is not presented below as it is impracticable to calculate due to the Company integrating the acquired assets into its overall operations using the full cost method of accounting. (In thousands) Revenue $ 26,226 Pro Forma Information (Unaudited) The following unaudited pro forma combined financial information presents the Company’s results as though the Vitruvian Acquisition had been completed at January 1, 2016. The pro forma combined financial information has been included for comparative purposes and is not necessarily indicative of the results that might have actually occurred had the Vitruvian Acquisition taken place on January 1, 2016; furthermore, the financial information is not intended to be a projection of future results. Three months ended March 31, 2017 2016 (In thousands, except share data) Pro forma revenue $ 368,903 $ 203,712 Pro forma net income (loss) $ 175,881 $ (274,207 ) Pro forma earnings (loss) per share (basic) $ 1.03 $ (2.03 ) Pro forma earnings (loss) per share (diluted) $ 1.03 $ (2.03 )

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment	PROPERTY AND EQUIPMENT The major categories of property and equipment and related accumulated depletion, depreciation, amortization and impairment as of March 31, 2017 and December 31, 2016 are as follows: March 31, 2017 December 31, 2016 (In thousands) Oil and natural gas properties $ 8,146,321 $ 6,071,920 Office furniture and fixtures 24,649 21,204 Building 45,204 42,530 Land 5,254 5,252 Total property and equipment 8,221,428 6,140,906 Accumulated depletion, depreciation, amortization and impairment (3,855,629 ) (3,789,780 ) Property and equipment, net $ 4,365,799 $ 2,351,126 Under the full cost method of accounting, the Company is required to perform a ceiling test each quarter. The test determines a limit, or ceiling, on the book value of the oil and gas properties. At March 31, 2017 , the calculated ceiling was greater than the net book value of the Company’s oil and natural gas properties, thus no ceiling test impairment was required for the three months ended March 31, 2017 . An impairment of $219.0 million was required for oil and natural gas properties for the three months ended March 31, 2016 . Included in oil and natural gas properties at March 31, 2017 is the cumulative capitalization of $138.3 million in general and administrative costs incurred and capitalized to the full cost pool. General and administrative costs capitalized to the full cost pool represent management’s estimate of costs incurred directly related to exploration and development activities such as geological and other administrative costs associated with overseeing the exploration and development activities. All general and administrative costs not directly associated with exploration and development activities were charged to expense as they were incurred. Capitalized general and administrative costs were approximately $8.4 million and $7.1 million for three months ended March 31, 2017 and 2016 , respectively. The following table summarizes the Company’s non-producing properties excluded from amortization by area at March 31, 2017 : March 31, 2017 (In thousands) Utica $ 1,592,683 MidCon 1,477,643 Niobrara 2,172 Southern Louisiana 484 Bakken 98 Other 368 $ 3,073,448 At December 31, 2016 , approximately $1.6 billion of non-producing leasehold costs was not subject to amortization. The Company evaluates the costs excluded from its amortization calculation at least annually. Subject to industry conditions and the level of the Company’s activities, the inclusion of most of the above referenced costs into the Company’s amortization calculation typically occurs within three to five years. However, the majority of the Company’s non-producing leases have five -year extension terms which could extend this time frame beyond five years. A reconciliation of the Company’s asset retirement obligation for the three months ended March 31, 2017 and 2016 is as follows: March 31, 2017 March 31, 2016 (In thousands) Asset retirement obligation, beginning of period $ 34,276 $ 26,437 Liabilities incurred 6,779 1,914 Liabilities settled — (52 ) Accretion expense 282 247 Asset retirement obligation as of end of period 41,337 28,546 Less current portion 195 75 Asset retirement obligation, long-term $ 41,142 $ 28,471

Equity Investments

Equity Investments	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments	EQUITY INVESTMENTS Investments accounted for by the equity method consist of the following as of March 31, 2017 and December 31, 2016 : Carrying value (Income) loss from equity method investments Approximate ownership % March 31, 2017 December 31, 2016 Three months ended March 31, 2017 2016 (In thousands) Investment in Tatex Thailand II, LLC 23.5 % $ — $ — $ (243 ) $ (159 ) Investment in Tatex Thailand III, LLC 17.9 % — — — — Investment in Grizzly Oil Sands ULC 24.9999 % 46,838 45,213 365 23,685 Investment in Timber Wolf Terminals LLC 50.0 % 987 991 4 3 Investment in Windsor Midstream LLC 22.5 % 25,815 25,749 (311 ) (167 ) Investment in Stingray Cementing LLC 50.0 % 1,768 1,920 128 30 Investment in Blackhawk Midstream LLC 48.5 % — — — — Investment in Stingray Energy Services LLC 50.0 % 3,967 4,215 197 502 Investment in Sturgeon Acquisitions LLC 25.0 % 20,458 20,526 68 377 Investment in Mammoth Energy Services, Inc. 24.2 % 110,875 111,717 2,158 6,466 Investment in Strike Force Midstream LLC 25.0 % 40,662 33,589 2,541 — $ 251,370 $ 243,920 $ 4,907 $ 30,737 The tables below summarize financial information for the Company’s equity investments as of March 31, 2017 and December 31, 2016 . Summarized balance sheet information: March 31, 2017 December 31, 2016 (In thousands) Current assets $ 151,587 $ 148,733 Noncurrent assets $ 1,342,012 $ 1,305,407 Current liabilities $ 97,329 $ 57,173 Noncurrent liabilities $ 59,721 $ 67,680 Summarized results of operations: Three months ended March 31, 2017 2016 (In thousands) Gross revenue $ 94,478 $ 43,307 Net loss $ (25,339 ) $ (25,308 ) Tatex Thailand II, LLC The Company has an indirect ownership interest in Tatex Thailand II, LLC (“Tatex II”). Tatex II holds an 8.5% interest in APICO, LLC (“APICO”), an international oil and gas exploration company. APICO has a reserve base located in Southeast Asia through its ownership of concessions covering approximately 180,000 acres which includes the Phu Horm Field. The Company received $0.2 million and $0.2 million in distributions from Tatex II during the three months ended March 31, 2017 and 2016, respectively. Tatex Thailand III, LLC The Company has an ownership interest in Tatex Thailand III, LLC (“Tatex III”). Tatex III previously owned a concession covering approximately 245,000 acres in Southeast Asia. As of December 31, 2014, the Company reviewed its investment in Tatex III and, together with Tatex III, made the decision to allow the concession to expire in January 2015. As such, the Company fully impaired the asset as of December 31, 2014. Grizzly Oil Sands ULC The Company, through its wholly owned subsidiary Grizzly Holdings Inc. (“Grizzly Holdings”), owns an interest in Grizzly Oil Sands ULC (“Grizzly”), a Canadian unlimited liability company. The remaining interest in Grizzly is owned by Grizzly Oil Sands Inc. (“Oil Sands”). As of March 31, 2017 , Grizzly had approximately 830,000 acres under lease in the Athabasca and Peace River oil sands regions of Alberta, Canada. Initiation of steam injection at its first project, Algar Lake Phase 1, commenced in January 2014 and first bitumen production was achieved during the second quarter of 2014. In April 2015, Grizzly determined to cease bitumen production at its Algar Lake facility due to the level of commodity prices. Grizzly continues to monitor market conditions as it assesses future plans for the facility. The Company reviewed its investment in Grizzly at March 31, 2016 for impairment based on FASB ASC 323 due to certain qualitative factors and as such, engaged an independent third party to assist management in determining fair value calculations of its investment. As a result of the calculated fair values and other qualitative factors, the Company concluded that an other than temporary impairment was required under FASB ASC 323, resulting in an impairment loss of $23.1 million for the three months ended March 31, 2016, which is included in loss from equity method investments, net in the consolidated statements of operations. As of and during the period ended March 31, 2017 , commodity prices had increased as compared to the quarter ended March 31, 2016, and there were no impairment indicators that required further evaluation for impairment. If commodity prices decline in the future however, further impairment of the investment in Grizzly may be necessary. During the three months ended March 31, 2017 , Gulfport paid $0.7 million in cash calls. Grizzly’s functional currency is the Canadian dollar. The Company’s investment in Grizzly was increased by $1.3 million and $10.3 million as a result of a foreign currency translation gain for the three months ended March 31, 2017 and 2016 , respectively. Timber Wolf Terminals LLC During 2012, the Company invested in Timber Wolf Terminals LLC (“Timber Wolf”). Timber Wolf was formed to operate a crude/condensate terminal and a sand transloading facility in Ohio. Windsor Midstream LLC At March 31, 2017 , the Company held a 22.5% interest in Windsor Midstream LLC (“Midstream”). Midstream holds common units of EnLink Midstream Partners, LP (“EnLink”) as a result of the sale of Coronado Midstream LLC to EnLink that occurred in March 2015. The Company received $0.2 million and $0.1 million in distributions from Midstream during the three months ended March 31, 2017 and 2016 , respectively. Stingray Cementing LLC During 2012, the Company invested in Stingray Cementing LLC (“Stingray Cementing”). Stingray Cementing provides well cementing services. The (income) loss from equity method investments presented in the table above reflects any intercompany profit eliminations. See Note 15 for subsequent event information regarding Mammoth Energy Services, Inc.’s pending acquisition of Stingray Cementing. Blackhawk Midstream LLC During 2012, the Company invested in Blackhawk Midstream LLC (“Blackhawk”). Blackhawk coordinated gathering, compression, processing and marketing activities for the Company in connection with the development of its Utica Shale acreage. Blackhawk does not have any current activities. Stingray Energy Services LLC During 2013, the Company invested in Stingray Energy Services LLC (“Stingray Energy”). Stingray Energy provides rental tools for land-based oil and natural gas drilling, completion and workover activities as well as the transfer of fresh water to wellsites. The (income) loss from equity method investments presented in the table above reflects any intercompany profit eliminations. See Note 15 for subsequent event information regarding Mammoth Energy Services, Inc.’s pending acquisition of Stingray Energy. Sturgeon Acquisitions LLC During 2014, the Company invested $20.7 million and received an ownership interest of 25% in Sturgeon Acquisitions LLC (“Sturgeon”). Sturgeon owns and operates sand mines that produce hydraulic fracturing grade sand. See Note 15 for subsequent event information regarding Mammoth Energy Services, Inc.’s pending acquisition of Sturgeon. Mammoth Energy Partners LP/Mammoth Energy Services, Inc. In the fourth quarter of 2014, the Company contributed its investments in four entities to Mammoth Energy Partners LP (“Mammoth”) for a 30.5% interest in this entity. Mammoth originally intended to pursue its initial public offering in 2014 or 2015; however, due to low commodity prices, the offering was postponed. In October 2016, Mammoth converted from a limited partnership into a limited liability company named Mammoth Energy Partners LLC (“Mammoth LLC”) and the Company and the other members of Mammoth LLC contributed their interests in Mammoth LLC to Mammoth Energy Services, Inc. (“Mammoth Energy”). The Company received 9,150,000 shares of Mammoth Energy common stock in return for its contribution. Following the contribution, Mammoth Energy completed its initial public offering (the “IPO”) of 7,750,000 shares of its common stock at a public offering price of $ 15.00 per share, of which 7,500,000 shares were sold by Mammoth Energy, and 250,000 shares were sold by certain selling stockholders, including 76,250 shares sold by the Company for which it received net proceeds of $1.1 million . At March 31, 2017 , the Company owned an approximate 24.2% interest in Mammoth Energy. The Company’s investment in Mammoth Energy was increased by a $0.1 million foreign currency gain and decreased by a $1.2 million foreign currency loss resulting from Mammoth Energy’s foreign subsidiary for the three months ended March 31, 2017 and 2016 , respectively. The (income) loss from equity method investments presented in the table above reflects any intercompany profit eliminations. See Note 15 for subsequent event information regarding Mammoth Energy’s pending acquisitions of Stingray Cementing, Stingray Energy and Sturgeon. Strike Force Midstream LLC In February 2016, the Company, through its wholly owned subsidiary Gulfport Midstream Holdings, LLC (“Midstream Holdings”), entered into an agreement with Rice Midstream Holdings LLC (“Rice”), a subsidiary of Rice Energy Inc., to develop natural gas gathering assets in eastern Belmont County and Monroe County, Ohio (the “dedicated areas”). The Company contributed certain gathering assets for a 25% interest in the newly formed entity called Strike Force Midstream LLC (“Strike Force”). Rice acts as operator and owns the remaining 75% interest in Strike Force. Construction of the gathering assets, which is underway, is expected to provide gathering services for Gulfport operated wells and connectivity of existing dry gas gathering systems. During the three months ended March 31, 2017 , Gulfport paid $10.0 million in cash calls to Strike Force and received distributions of $0.4 million from Strike Force. The Company accounted for its contribution to Strike Force at fair value under applicable codification guidance. The Company estimated the fair market value of its investment in Strike Force as of the contribution date using the discounted cash flow method under the income approach, based on an independently prepared valuation of the contributed assets. The fair market value was reduced by a discount factor for the lack of marketability due to the Company’s minority interest, resulting in a fair value of $22.5 million for the Company’s 25% interest. The fair value of the assets contributed was estimated using assumptions that represent Level 3 inputs. See “Note 11 - Fair Value Measurements” for additional discussion of the measurement inputs. The Company has elected to report its proportionate share of Strike Force’s earnings on a one-quarter lag as permitted under FASB ASC 323. The (income) loss from equity method investments presented in the table above reflects any intercompany profit eliminations.

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2017
Related Party Transactions [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES As of March 31, 2017 , the Company held variable interests in the following variable interest entities (“VIEs”), but was not the primary beneficiary: Stingray Energy, Stingray Cementing, Sturgeon, Midstream and Timber Wolf. These entities have governing provisions that are the functional equivalent of a limited partnership and are considered VIEs because the limited partners or non-managing members lack substantive kick-out or participating rights which causes the equity owners, as a group, to lack a controlling financial interest. The Company is a limited partner or non-managing member in each of these VIEs and is not the primary beneficiary because it does not have a controlling financial interest. The general partner or managing member has power to direct the activities that most significantly impact the VIEs’ economic performance. The Company also held a variable interest in Strike Force due to the fact that it does not have sufficient equity capital at risk. The Company is not the primary beneficiary of this entity. Prior to Mammoth Energy’s IPO, Mammoth LLC was considered a variable interest entity. As a result of the Company’s contribution of its interest in Mammoth LLC to Mammoth Energy in exchange for Mammoth Energy common stock and Mammoth Energy’s IPO, the Company determined that it no longer held an interest in a variable interest entity. The Company accounts for its investment in these VIEs following the equity method of accounting. The carrying amounts of the Company’s equity investments are classified as other non-current assets on the accompanying consolidated balance sheets. The Company’s maximum exposure to loss as a result of its involvement with these VIEs is based on the Company’s capital contributions and the economic performance of the VIEs, and is equal to the carrying value of the Company’s investments which is the maximum loss the Company could be required to record in the consolidated statements of operations. See Note 3 for further discussion of these entities, including the carrying amounts of each investment.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2017
Long-term Debt, Unclassified [Abstract]
Long-Term Debt	LONG-TERM DEBT Long-term debt consisted of the following items as of March 31, 2017 and December 31, 2016 : March 31, 2017 December 31, 2016 (In thousands) Revolving credit agreement (1) $ 40,000 $ — 7.75% senior unsecured notes due 2020 (2) — — 6.625% senior unsecured notes due 2023 (3) 350,000 350,000 6.000% senior unsecured notes due 2024 (4) 650,000 650,000 6.375% senior unsecured notes due 2025 (5) 600,000 600,000 Net unamortized debt issuance costs (6) (31,486 ) (27,174 ) Construction loan (7) 23,747 21,049 Less: current maturities of long term debt (452 ) (276 ) Debt reflected as long term $ 1,631,809 $ 1,593,599 The Company capitalized approximately $3.1 million and $1.6 million in interest expense to undeveloped oil and natural gas properties during the three months ended March 31, 2017 and 2016 , respectively. During the three months ended March 31, 2016, the Company capitalized $0.3 million in interest expense related to building construction. Construction on the building was completed in December 2016 and, as such, the Company did not capitalize any interest expense related to building construction for the three months ended March 31, 2017 . (1) The Company has entered into a senior secured revolving credit facility, as amended, with The Bank of Nova Scotia, as the lead arranger and administrative agent and certain lenders from time to time party thereto. The credit agreement provides for a maximum facility amount of $1.5 billion and matures on June 6, 2018. On December 13, 2016, the Company further amended its revolving credit facility to, among other things, (a) reset the maturity date to December 31, 2021, (b) adjust lenders, (c) increase the basket for unsecured debt issuances to $1.6 billion , (d) increase the interest rates by 50 basis points, (e) increase the mortgage requirement to 85% (from 80% ), and (f) add deposit account control agreement language. On March 29, 2017, the Company further amended its revolving credit facility to, among other things, amend the definition of the term EBITDAX to permit pro forma treatment of acquisitions that involve the payment of consideration by Gulfport and its subsidiaries in excess of $50.0 million and of dispositions of property or series of related dispositions of properties that yields gross proceeds to Gulfport or any of its subsidiaries in excess of $50.0 million . As of March 31, 2017 , the borrowing base was set at $700.0 million and $40.0 million was outstanding under the revolving credit facility. At March 31, 2017 , the total availability for future borrowings under the revolving credit facility, after giving effect to an aggregate of $238.7 million of letters of credit, was $421.3 million . The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. On May 4, 2017, the revolving credit facility was further amended to increase the borrowing base from $700.0 million to $1.0 billion , adjust certain of the Company's investment baskets and add five additional banks to the syndicate. Advances under the revolving credit facility may be in the form of either base rate loans or eurodollar loans. The interest rate for base rate loans is equal to (1) the applicable rate, which ranges from 1.00% to 2.00% , plus (2) the highest of: (a) the federal funds rate plus 0.50% , (b) the rate of interest in effect for such day as publicly announced from time to time by agent as its “prime rate,” and (c) the eurodollar rate for an interest period of one month plus 1.00% . The interest rate for eurodollar loans is equal to (1) the applicable rate, which ranges from 2.00% to 3.00% , plus (2) the London interbank offered rate that appears on pages LIBOR01 or LIBOR02 of the Reuters screen that displays such rate for deposits in U.S. dollars, or, if such rate is not available, the rate as administered by ICE Benchmark Administration (or any other person that takes over administration of such rate) per annum equal to the offered rate on such other page or service that displays on average London interbank offered rate as determined by ICE Benchmark Administration (or any other person that takes over administration of such rate) for deposits in U.S. dollars, or, if such rate is not available, the average quotations for three major New York money center banks of whom the agent shall inquire as the “London Interbank Offered Rate” for deposits in U.S. dollars. At March 31, 2107, amounts borrowed under the credit facility bore interest at the eurodollar rate ( 3.18% ). The revolving credit facility contains customary negative covenants including, but not limited to, restrictions on the Company’s and its subsidiaries’ ability to: • incur indebtedness; • grant liens; • pay dividends and make other restricted payments; • make investments; • make fundamental changes; • enter into swap contracts and forward sales contracts; • dispose of assets; • change the nature of their business; and • enter into transactions with affiliates. The negative covenants are subject to certain exceptions as specified in the revolving credit facility. The revolving credit facility also contains certain affirmative covenants, including, but not limited to the following financial covenants: (i) the ratio of net funded debt to EBITDAX (net income, excluding (i) any non-cash revenue or expense associated with swap contracts resulting from ASC 815 and (ii) any cash or non-cash revenue or expense attributable to minority investments plus without duplication and, in the case of expenses, to the extent deducted from revenues in determining net income, the sum of (a) the aggregate amount of consolidated interest expense for such period, (b) the aggregate amount of income, franchise, capital or similar tax expense (other than ad valorem taxes) for such period, (c) all amounts attributable to depletion, depreciation, amortization and asset or goodwill impairment or writedown for such period, (d) all other non-cash charges, (e) exploration costs deducted in determining net income under successful efforts accounting, (f) actual cash distributions received from minority investments, (g) to the extent actually reimbursed by insurance, expenses with respect to liability on casualty events or business interruption, and (h) all reasonable transaction expenses related to dispositions and acquisitions of assets, investments and debt and equity offerings (provided that expenses related to any unsuccessful disposition will be limited to $3.0 million in the aggregate) for a twelve-month period may not be greater than 4.00 to 1.00 ; and (ii) the ratio of EBITDAX to interest expense for a twelve-month period may not be less than 3.00 to 1.00 . The Company was in compliance with all covenants at March 31, 2017 . (2) On October 17, 2012, the Company issued $250.0 million in aggregate principal amount of 7.75% Senior Notes due 2020 (the “October Notes”) under an indenture among the Company, its subsidiary guarantors and Wells Fargo Bank, National Association, as the trustee (the “senior note indenture”). On December 21, 2012, the Company issued an additional $50.0 million in aggregate principal amount of 7.75% Senior Notes due 2020 (the “December Notes”) as additional securities under the senior note indenture. On August 18, 2014, the Company issued an additional $300.0 million in aggregate principal amount of 7.75% Senior Notes due 2020 (the “August Notes”). The August Notes were issued as additional securities under the senior note indenture. The October Notes, December Notes and the August Notes are collectively referred to as the “2020 Notes.” In October 2016 , the Company repurchased (in a cash tender offer) or redeemed all of the 2020 Notes, of which $600.0 million in aggregate principal amount was then outstanding, with the net proceeds from the issuance of its 6.000% Senior Notes due 2024 (the “2024 Notes”) discussed below and cash on hand, and the indenture governing the 2020 Notes was fully satisfied and discharged. (3) On April 21, 2015, the Company issued $350.0 million in aggregate principal amount of 6.625% Senior Notes due 2023 (the “2023 Notes”) to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2023 Notes Offering”). The Company received net proceeds of approximately $343.6 million after initial purchaser discounts and commissions and estimated offering expenses. The 2023 Notes were issued under an indenture, dated as of April 21, 2015, among the Company, the subsidiary guarantors party thereto and Wells Fargo Bank, National Association, as trustee. In October 2015, the 2023 Notes were exchanged for a new issue of substantially identical debt securities registered under the Securities Act. Pursuant to the indenture relating to the 2023 Notes, interest on the 2023 Notes will accrue at a rate of 6.625% per annum on the outstanding principal amount thereof from April 21, 2015, payable semi-annually on May 1 and November 1 of each year, commencing on November 1, 2015. The 2023 Notes are not guaranteed by Grizzly Holdings, Inc. and will not be guaranteed by any of the Company’s future unrestricted subsidiaries. (4) On October 14, 2016, the Company issued the 2024 Notes in aggregate principal amount of $650.0 million . The 2024 Notes were issued under an indenture, dated as of October 14, 2016, among the Company, the subsidiary guarantors party thereto and the senior note indenture trustee (the “2024 Indenture”), to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2024 Notes Offering”). Under the 2024 Indenture, interest on the 2024 Notes accrues at a rate of 6.000% per annum on the outstanding principal amount thereof from October 14, 2016, payable semi-annually on April 15 and October 15 of each year, commencing on April 15, 2017. The 2024 Notes will mature on October 15, 2024. The Company received approximately $638.9 million in net proceeds from the offering of the 2024 Notes, which was used, together with cash on hand, to purchase the outstanding 2020 Notes in a concurrent cash tender offer, to pay fees and expenses thereof, and to redeem any of the 2020 Notes that remained outstanding after the completion of the tender offer. (5) On December 21, 2016, the Company issued $600.0 million in aggregate principal amount of 6.375% Senior Notes due 2025 (the “2025 Notes”). The 2025 Notes were issued under an indenture, dated as of December 21, 2016, among the Company, the subsidiary guarantors party thereto and the senior note indenture trustee (the “2025 Indenture”), to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, and to certain non-U.S. persons in accordance with Regulation S under the Securities Act. Under the 2025 Indenture, interest on the 2025 Notes accrues at a rate of 6.375% per annum on the outstanding principal amount thereof from December 21, 2016, payable semi-annually on May 15 and November 15 of each year, commencing on May 15, 2017. The 2025 Notes will mature on May 15, 2025. The Company received approximately $584.7 million in net proceeds from the offering of the 2025 Notes, which was used, together with the net proceeds from the Company’s December 2016 common stock offering and cash on hand, to fund the cash portion of the purchase price for the Vitruvian Acquisition. See “Note 1 – Acquisitions” for additional discussion of the Vitruvian Acquisition. (6) In accordance with ASU 2015-03, loan issuance costs related to the 2023 Notes, the 2024 Notes and the 2025 Notes (collectively the “Notes”) have been presented as a reduction to the Notes. At March 31, 2017 , total unamortized debt issuance costs were $5.8 million for the 2023 Notes, $10.7 million for the 2024 Notes and $14.9 million for the 2025 Notes. In addition, loan commitment fee costs for the construction loan agreement described immediately below were $0.1 million at March 31, 2017 . (7) On June 4, 2015, the Company entered into a construction loan agreement (the “Construction Loan”) with InterBank for the construction of a new corporate headquarters in Oklahoma City, which was substantially completed in December 2016. The Construction Loan allows for maximum principal borrowings of $24.5 million and required the Company to fund 30% of the cost of the construction before any funds could be drawn, which occurred in January 2016. Interest accrues daily on the outstanding principal balance at a fixed rate of 4.50% per annum and is payable on the last day of the month through May 31, 2017. Monthly interest and principal payments are due beginning June 30, 2017, with the final payment due June 4, 2025. At March 31, 2017 , the total borrowings under the Construction Loan were approximately $23.7 million .

Common Stock and Changes In Cap

Common Stock and Changes In Capitalization	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Common Stock and Changes in Capitalization	COMMON STOCK AND CHANGES IN CAPITALIZATION Issuance of Common Stock On March 15, 2016, the Company issued 16,905,000 shares of its common stock in an underwritten public offering (which included 2,205,000 shares sold pursuant to an option to purchase shares sold pursuant to an option to purchase additional shares of the Company’s common stock granted by the Company to, and exercised in full by, the underwriters). The net proceeds from this equity offering were approximately $411.9 million , after underwriting discounts and commissions and offering expenses. The Company used the net proceeds from this offering primarily to fund a portion of its 2017 capital development plan and for general corporate purposes. On February 17, 2017, the Company completed the Vitruvian Acquisition for a total initial purchase price of approximately $1.85 billion , consisting of $1.35 billion in cash, subject to certain adjustments, and approximately 23.9 million shares of the Company’s common stock (of which approximately 5.2 million shares are subject to the indemnity escrow). See “Note 1 - Acquisitions” for additional discussion of the Vitruvian Acquisition.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2017
Share-based Compensation [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION During the three months ended March 31, 2017 and 2016 , the Company’s stock-based compensation cost was $ 2.6 million and $3.3 million , respectively, of which the Company capitalized $1.0 million and $1.3 million , respectively, relating to its exploration and development efforts. The following table summarizes restricted stock activity for the three months ended March 31, 2017 : Number of Unvested Restricted Shares Weighted Average Grant Date Fair Value Unvested shares as of January 1, 2017 613,056 $ 32.90 Granted 477,768 17.74 Vested (153,868 ) 31.98 Forfeited (65,438 ) 31.23 Unvested shares as of March 31, 2017 871,518 $ 24.88 Unrecognized compensation expense as of March 31, 2017 related to restricted shares was $18.1 million . The expense is expected to be recognized over a weighted average period of 1.66 years.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Reconciliations of the components of basic and diluted net income (loss) per common share are presented in the tables below: Three months ended March 31, 2017 2016 Income Shares Per Share (Loss) Shares Per Share (In thousands, except share data) Basic: Net income (loss) $ 154,455 170,272,685 $ 0.91 $ (242,267 ) 111,509,585 $ (2.17 ) Effect of dilutive securities: Stock options and awards — 215,834 — — Diluted: — Net income (loss) $ 154,455 170,488,519 $ 0.91 $ (242,267 ) 111,509,585 $ (2.17 ) There were 650,606 shares of common stock that were considered anti-dilutive for the three months ended March 31, 2016.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Plugging and Abandonment Funds In connection with the Company’s acquisition in 1997 of the remaining 50% interest in its WCBB properties, the Company assumed the seller’s (Chevron) obligation to contribute approximately $18,000 per month through March 2004 to a plugging and abandonment trust and the obligation to plug a minimum of 20 wells per year for 20 years commencing March 11, 1997. Chevron retained a security interest in production from these properties until the Company’s abandonment obligations to Chevron have been fulfilled. Beginning in 2009, the Company could access the trust for use in plugging and abandonment charges associated with the property, although it has not yet done so. As of March 31, 2017 , the plugging and abandonment trust totaled approximately $3.1 million . At March 31, 2017 , the Company had plugged 513 wells at WCBB since it began its plugging program in 1997, which management believes fulfills its minimum plugging obligation. Operating Leases The Company leases office facilities under non-cancellable operating leases exceeding one year. Future minimum lease commitments under these leases at March 31, 2017 were as follows: (In thousands) Remaining 2017 $ 129 2018 54 Total $ 183 Firm Transportation Commitments The Company had approximately 2,952,375 MMBtu per day of firm sales contracted with third parties. The table below presents these commitments at March 31, 2017 as follows: (MMBtu per day) Remaining 2017 725,625 2018 457,000 2019 604,750 2020 518,000 2021 371,000 Thereafter 276,000 Total 2,952,375 The Company also had approximately $3.8 billion of firm transportation contracted with third parties. The table below presents these commitments at March 31, 2017 as follows: (In thousands) Remaining 2017 $ 143,816 2018 241,709 2019 241,708 2020 240,746 2021 239,786 Thereafter 2,705,270 Total $ 3,813,035 Other Commitments Effective October 1, 2014, the Company entered into a Sand Supply Agreement with Muskie Proppant LLC (“Muskie”), a subsidiary of Mammoth Energy, that expires on September 30, 2018. Pursuant to this agreement, as amended, the Company has agreed to purchase annual and monthly amounts of proppant sand subject to exceptions specified in the agreement at agreed pricing plus agreed costs and expenses. Failure by either Muskie or the Company to deliver or accept the minimum monthly amount results in damages calculated per ton based on the difference between the monthly obligation amount and the amount actually delivered or accepted, as applicable. The Company incurred $1.3 million related to non-utilization fees during the three months ended March 31, 2016 . The Company did not incur any non-utilization fees during the three months ended March 31, 2017 . Effective October 1, 2014, the Company entered into an Amended and Restated Master Services Agreement for pressure pumping services with Stingray Pressure Pumping LLC (“Stingray Pressure”), a subsidiary of Mammoth Energy, that expires on September 30, 2018. Pursuant to this agreement, as amended, Stingray Pressure has agreed to provide hydraulic fracturing, stimulation and related completion and rework services to the Company and the Company has agreed to pay Stingray Pressure a monthly service fee plus the associated costs of the services provided. Future minimum commitments under these agreements at March 31, 2017 are as follows: (In thousands) Remaining 2017 $ 39,330 2018 39,330 Total $ 78,660 Litigation In two separate complaints, one filed by the State of Louisiana and the Parish of Cameron in the 38th Judicial District Court for the Parish of Cameron on February 9, 2016 and the other filed by the State of Louisiana and the District Attorney for the 15 th Judicial District of the State of Louisiana in the 15 th Judicial District Court for the Parish of Vermillion on July 29, 2016, the Company was named as a defendant, among 26 oil and gas companies, in the Cameron Parish complaint and among more than 40 oil and gas companies in the Vermillion Parish complaint, or the Complaints. The Complaints were filed under the State and Local Coastal Resources Management Act of 1978, as amended, and the rules, regulations, orders and ordinances adopted thereunder, which the Company referred to collectively as the CZM Laws, and allege that certain of the defendants’ oil and gas exploration, production and transportation operations associated with the development of the East Hackberry and West Hackberry oil and gas fields, in the case of the Cameron Parish complaint, and the Tigre Lagoon oil and gas field, in the case of the Vermillion Parish complaint, were conducted in violation of the CZM Laws. The Complaints allege that such activities caused substantial damage to land and waterbodies located in the coastal zone of the relevant Parish, including due to defendants’ design, construction and use of waste pits and the alleged failure to properly close the waste pits and to clear, re-vegetate, detoxify and return the property affected to its original condition, as well as the defendants’ alleged discharge of waste into the coastal zone. The Complaints also allege that the defendants’ oil and gas activities have resulted in the dredging of numerous canals, which had a direct and significant impact on the state coastal waters within the relevant Parish and that the defendants, among other things, failed to design, construct and maintain these canals using the best practical techniques to prevent bank slumping, erosion and saltwater intrusion and to minimize the potential for inland movement of storm-generated surges, which activities allegedly have resulted in the erosion of marshes and the degradation of terrestrial and aquatic life therein. The Complaints also allege that the defendants failed to re-vegetate, refill, clean, detoxify and otherwise restore these canals to their original condition. In these two petitions, the plaintiffs seek damages and other appropriate relief under the CZM Laws, including the payment of costs necessary to clear, re-vegetate, detoxify and otherwise restore the affected coastal zone of the relevant Parish to its original condition, actual restoration of such coastal zone to its original condition, and the payment of reasonable attorney fees and legal expenses and pre-judgment and post judgment interest. The Company was served with the Cameron complaint in early May 2016 and with the Vermillion complaint in early September 2016. The Louisiana Attorney General and the Louisiana Department of Natural Resources intervened in both the Cameron Parish suit and the Vermillion Parish suit. Shortly after the Complaints were filed, certain defendants removed the cases to the lawsuit to the United States District Court for the Western District of Louisiana. In both cases, the plaintiffs have filed a motion to remand, but both Courts have stayed further proceedings on the motions to remand pending a ruling from the United States Court of Appeals, Fifth Circuit on similar jurisdictional issues in another matter. In March 2017, the United States Court of Appeals, Fifth Circuit issued its ruling. Subsequently, the Vermillion Parish case and Cameron Parish case have both had their respective stays lifted. A hearing on the remand motions has been scheduled for May 17, 2017 in the Vermillion Parish case. No hearing on the remand motions has been set for the Cameron Parish case. The plaintiffs have granted all defendants an extension of time to file responsive pleadings to the Complaints until the District Courts rule on the motions to remand. The Company has not had the opportunity to evaluate the applicability of the allegations made in such complaints to their operations. Due to the early stages of these matters, management cannot determine the amount of loss, if any, that may result. In addition, due to the nature of the Company’s business, it is, from time to time, involved in routine litigation or subject to disputes or claims related to its business activities, including workers’ compensation claims and employment related disputes. In the opinion of the Company’s management, none of the pending litigation, disputes or claims against the Company, if decided adversely, will have a material adverse effect on its financial condition, cash flows or results of operations.

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2017
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Derivative Instruments	DERIVATIVE INSTRUMENTS Natural Gas, Oil and Natural Gas Liquids Derivative Instruments The Company seeks to reduce its exposure to unfavorable changes in natural gas, oil and natural gas liquids prices, which are subject to significant and often volatile fluctuation, by entering into over-the-counter fixed price swaps, basis swaps and various types of option contracts. These contracts allow the Company to predict with greater certainty the effective natural gas, oil and natural gas liquids prices to be received for hedged production and benefit operating cash flows and earnings when market prices are less than the fixed prices provided in the contracts. However, the Company will not benefit from market prices that are higher than the fixed prices in the contracts for hedged production. Fixed price swaps are settled monthly based on differences between the fixed price specified in the contract and the referenced settlement price. When the referenced settlement price is less than the price specified in the contract, the Company receives an amount from the counterparty based on the price difference multiplied by the volume. Similarly, when the referenced settlement price exceeds the price specified in the contract, the Company pays the counterparty an amount based on the price difference multiplied by the volume. The prices contained in these fixed price swaps are based on the NYMEX Henry Hub for natural gas, Argus Louisiana Light Sweet Crude for oil, the NYMEX West Texas Intermediate for oil, and Mont Belvieu for propane and pentane. Below is a summary of the Company’s open fixed price swap positions as of March 31, 2017 . Location Daily Volume (MMBtu/day) Weighted Remaining 2017 NYMEX Henry Hub 576,845 $ 3.18 2018 NYMEX Henry Hub 543,767 $ 3.09 2019 NYMEX Henry Hub 9,863 $ 3.27 Location Daily Volume Weighted Remaining 2017 ARGUS LLS 1,665 $ 52.32 Remaining 2017 NYMEX WTI 4,113 $ 54.97 2018 NYMEX WTI 899 $ 55.31 Location Daily Volume Weighted Remaining 2017 Mont Belvieu C3 3,000 $ 26.63 Remaining 2017 Mont Belvieu C5 250 $ 49.14 The Company sold call options and used the associated premiums to enhance the fixed price for a portion of the fixed price natural gas swaps listed above. Each short call option has an established ceiling price. When the referenced settlement price is above the price ceiling established by these short call options, the Company pays its counterparty an amount equal to the difference between the referenced settlement price and the price ceiling multiplied by the hedged contract volumes. Location Daily Volume (MMBtu/day) Weighted Average Price Remaining 2017 NYMEX Henry Hub 65,000 $ 3.11 2018 NYMEX Henry Hub 80,000 $ 3.29 2019 NYMEX Henry Hub 4,932 $ 3.16 For a portion of the combined natural gas derivative instruments containing fixed price swaps and sold call options, the counterparty has an option to extend the original terms an additional twelve months for the period January 2018 through December 2018. The option to extend the terms expires in December 2017. If executed, the Company would have additional fixed price swaps for 30,000 MMBtu per day with the option to double at a weighted average price of $3.36 per MMBtu and additional short call options for 30,000 MMBtu per day with the option to double at a weighted average ceiling price of $3.36 per MMBtu. In addition, the Company has entered into natural gas basis swap positions, which settle on the pricing index to basis differential of NGPL Mid-Continent to NYMEX Henry Hub. As of March 31, 2017 , the Company had the following natural gas basis swap positions for NGPL Mid-Continent. Location Daily Volume (MMBtu/day) Hedged Differential Remaining 2017 NGPL Mid-Continent 50,000 $ (0.26 ) 2018 NGPL Mid-Continent 12,329 $ (0.26 ) Balance Sheet Presentation The Company reports the fair value of derivative instruments on the consolidated balance sheets as derivative instruments under current assets, noncurrent assets, current liabilities and noncurrent liabilities on a gross basis. The Company determines the current and noncurrent classification based on the timing of expected future cash flows of individual trades. The following table presents the fair value of the Company’s derivative instruments on a gross basis at March 31, 2017 and December 31, 2016 : March 31, 2017 December 31, 2016 (In thousands) Short-term derivative instruments - asset $ 18,925 $ 3,488 Long-term derivative instruments - asset $ 23,515 $ 5,696 Short-term derivative instruments - liability $ 67,179 $ 119,219 Long-term derivative instruments - liability $ 5,259 $ 26,759 Gains and Losses The following table presents the gain and loss recognized in Net gain on gas, oil and NGL derivatives in the accompanying consolidated statements of operations for the three months ended March 31, 2017 and 2016 . Net gain (loss) on derivative instruments Three months ended March 31, 2017 2016 (In thousands) Natural gas derivatives $ 86,277 $ 57,000 Oil derivatives 10,905 1,282 Natural gas liquids derivatives 2,395 (547 ) Total $ 99,577 $ 57,735 Offsetting of derivative assets and liabilities As noted above, the Company records the fair value of derivative instruments on a gross basis. The following table presents the gross amounts of recognized derivative assets and liabilities in the consolidated balance sheets and the amounts that are subject to offsetting under master netting arrangements with counterparties, all at fair value. As of March 31, 2017 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 42,440 $ (41,180 ) $ 1,260 Derivative liabilities $ (72,438 ) $ 41,180 $ (31,258 ) As of December 31, 2016 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 9,184 $ (9,184 ) $ — Derivative liabilities $ (145,978 ) $ 9,184 $ (136,794 ) Concentration of Credit Risk By using derivative instruments that are not traded on an exchange, the Company is exposed to the credit risk of its counterparties. Credit risk is the risk of loss from counterparties not performing under the terms of the derivative instrument. When the fair value of a derivative instrument is positive, the counterparty is expected to owe the Company, which creates credit risk. To minimize the credit risk in derivative instruments, it is the Company’s policy to enter into derivative contracts only with counterparties that are creditworthy financial institutions deemed by management as competent and competitive market makers. The Company’s derivative contracts are with multiple counterparties to lessen its exposure to any individual counterparty. Additionally, the Company uses master netting agreements to minimize credit risk exposure. The creditworthiness of the Company’s counterparties is subject to periodic review. None of the Company’s derivative instrument contracts contain credit-risk related contingent features. Other than as provided by the Company’s revolving credit facility, the Company is not required to provide credit support or collateral to any of its counterparties under its derivative instruments, nor are the counterparties required to provide credit support to the Company.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Company records certain financial and non-financial assets and liabilities on the balance sheet at fair value in accordance with FASB ASC 820, “Fair Value Measurement and Disclosures” (“FASB ASC 820”). FASB ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability (exit price) in an orderly transaction between market participants at the measurement date. The statement establishes market or observable inputs as the preferred sources of values, followed by assumptions based on hypothetical transactions in the absence of market inputs. The statement requires fair value measurements be classified and disclosed in one of the following categories: Level 1 – Quoted prices in active markets for identical assets and liabilities. Level 2 – Quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar instruments in markets that are not active and model-derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 – Significant inputs to the valuation model are unobservable. Valuation techniques that maximize the use of observable inputs are favored. 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 assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the placement of assets and liabilities within the levels of the fair value hierarchy. Reclassifications of fair value between Level 1, Level 2 and Level 3 of the fair value hierarchy, if applicable, are made at the end of each quarter. The following tables summarize the Company’s financial and non-financial assets and liabilities by FASB ASC 820 valuation level as of March 31, 2017 and December 31, 2016 : March 31, 2017 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 42,440 $ — Liabilities: Derivative Instruments $ — $ 72,438 $ — December 31, 2016 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 9,184 $ — Liabilities: Derivative Instruments $ — $ 145,978 $ — The Company estimates the fair value of all derivative instruments industry-standard models that considered various assumptions including current market and contractual prices for the underlying instruments, implied volatility, time value, nonperformance risk, as well as other relevant economic measures. Substantially all of these inputs are observable in the marketplace throughout the full term of the instrument and can be supported by observable data. The estimated fair values of proved oil and gas properties assumed in business combinations are based on a discounted cash flow model and market assumptions as to future commodity prices, projections of estimated quantities of oil and natural gas reserves, expectations for timing and amount of future development and operating costs, projections of future rates of production, expected recovery rates and risk-adjusted discount rates. The estimated fair values of unevaluated oil and gas properties was based on geological studies, historical well performance, location and applicable mineral lease terms. Based on the unobservable nature of certain of the inputs, the estimated fair value of the oil and gas properties assumed is deemed to use Level 3 inputs. The asset retirement obligations assumed as part of the business combination were estimated using the same assumptions and methodology as described below. See Note 1 for further discussion of the Vitruvian Acquisition. The Company estimates asset retirement obligations pursuant to the provisions of FASB ASC Topic 410, Asset Retirement and Environmental Obligations (“FASB ASC 410”). The initial measurement of asset retirement obligations at fair value is calculated using discounted cash flow techniques and based on internal estimates of future retirement costs associated with oil and gas properties. Given the unobservable nature of the inputs, including plugging costs and reserve lives, the initial measurement of the asset retirement obligation liability is deemed to use Level 3 inputs. See Note 2 for further discussion of the Company’s asset retirement obligations. Asset retirement obligations incurred during the three months ended March 31, 2017 were approximately $6.8 million . Due to the unobservable nature of the inputs, the fair value of the Company’s investment in Grizzly was estimated using assumptions that represent Level 3 inputs. The Company estimated the fair value of the investment as of March 31, 2016 to be approximately $39.1 million . See Note 3 for further discussion of the Company’s investment in Grizzly. Due to the unobservable nature of the inputs, the fair value of the Company’s investment in Strike Force was estimated using assumptions that represent Level 3 inputs. The Company’s estimated fair value of the investment as of the February 1, 2016 contribution date was $22.5 million . See Note 3 for further discussion of the Company’s contribution to Strike Force.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2017
Investments, All Other Investments [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS The carrying amounts on the accompanying consolidated balance sheet for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities, and current debt are carried at cost, which approximates market value due to their short-term nature. Long-term debt related to the Construction Loan is carried at cost, which approximates market value based on the borrowing rates currently available to the Company with similar terms and maturities. At March 31, 2017 , the carrying value of the outstanding debt represented by the Notes was approximately $1.6 billion , including the unamortized debt issuance cost of approximately $5.8 million related to the 2023 Notes, approximately $10.7 million related to the 2024 Notes and approximately $14.9 million related to the 2025 Notes. Based on the quoted market price, the fair value of the Notes was determined to be approximately $1.6 billion at March 31, 2017 .

Condensed Consolidating Financi

Condensed Consolidating Financial Information	3 Months Ended
	Mar. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Financial Information	CONDENSED CONSOLIDATING FINANCIAL INFORMATION On October 17, 2012, December 21, 2012 and August 18, 2014, the Company issued the 2020 Notes in an aggregate of $600.0 million principal amount. The 2020 Notes were subsequently exchanged for substantially identical notes in the same aggregate principal amount that were registered under the Securities Act. In October 2016, the Company repurchased (in a cash tender offer) or redeemed all of the 2020 Notes, of which $600.0 million in aggregate principal amount was then outstanding, with the net proceeds from the issuance of the 2024 Notes discussed below and cash on hand. On April 21, 2015, the Company issued $350.0 million in aggregate principal amount of the 2023 Notes to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act. In connection with the 2023 Notes Offering, the Company and its subsidiary guarantors entered into a registration rights agreement, dated as of April 21, 2015, pursuant to which the Company agreed to file a registration statement with respect to an offer to exchange the 2023 Notes for a new issue of substantially identical debt securities registered under the Securities Act. The exchange offer for the 2023 Notes was completed on October 13, 2015. On October 14, 2016, the Company issued $650.0 million in aggregate principal amount of the 2024 Notes to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act. The net proceeds from the issuance of the 2024 Notes, together with cash on hand, were used to repurchase or redeem all of the then-outstanding 2020 Notes in October 2016. On December 21, 2016, the Company issued $600.0 million in aggregate principal amount of the 2025 Notes to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act. The Company used the net proceeds from the issuance of the 2025 Notes, together with the net proceeds from the December 2016 underwritten offering of the Company’s common stock and cash on hand, to fund the cash portion of the purchase price for the Vitruvian Acquisition. The 2020 Notes were, and the 2023 Notes, the 2024 Notes and the 2025 Notes are, guaranteed on a senior unsecured basis by all existing consolidated subsidiaries that guarantee the Company’s secured revolving credit facility or certain other debt (the “Guarantors”). The 2020 Notes were not, and the 2023 Notes, the 2024 Notes and the 2025 Notes are not, guaranteed by Grizzly Holdings, Inc. (the “Non-Guarantor”). The Guarantors are 100% owned by Gulfport (the “Parent”), and the guarantees are full, unconditional, joint and several. There are no significant restrictions on the ability of the Parent or the Guarantors to obtain funds from each other in the form of a dividend or loan. The following condensed consolidating balance sheets, statements of operations, statements of comprehensive (loss) income and statements of cash flows are provided for the Parent, the Guarantors and the Non-Guarantor and include the consolidating adjustments and eliminations necessary to arrive at the information for the Company on a condensed consolidated basis. The information has been presented using the equity method of accounting for the Parent’s ownership of the Guarantors and the Non-Guarantor. CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 71,934 $ 30,550 $ 1 $ — $ 102,485 Accounts receivable - oil and gas 106,008 52,146 — — 158,154 Accounts receivable - related parties 39 — — — 39 Accounts receivable - intercompany 447,275 35,434 — (482,709 ) — Prepaid expenses and other current assets 12,330 3,675 — — 16,005 Short-term derivative instruments 18,925 — — — 18,925 Total current assets 656,511 121,805 1 (482,709 ) 295,608 Property and equipment: Oil and natural gas properties, full-cost accounting 5,869,066 2,277,984 — (729 ) 8,146,321 Other property and equipment 75,064 43 — — 75,107 Accumulated depletion, depreciation, amortization and impairment (3,855,594 ) (35 ) — — (3,855,629 ) Property and equipment, net 2,088,536 2,277,992 — (729 ) 4,365,799 Other assets: Equity investments and investments in subsidiaries 2,120,462 40,661 46,838 (1,956,591 ) 251,370 Long-term derivative instruments 23,515 — — — 23,515 Deferred tax asset 4,692 — — — 4,692 Other assets 8,765 4,180 — — 12,945 Total other assets 2,157,434 44,841 46,838 (1,956,591 ) 292,522 Total assets $ 4,902,481 $ 2,444,638 $ 46,839 $ (2,440,029 ) $ 4,953,929 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 326,175 $ 79,964 $ — $ — $ 406,139 Accounts payable - intercompany 35,005 447,577 127 (482,709 ) — Asset retirement obligation 195 — — — 195 Derivative instruments 67,179 — — — 67,179 Current maturities of long-term debt 452 — — — 452 Total current liabilities 429,006 527,541 127 (482,709 ) 473,965 Long-term derivative instrument 5,259 — — — 5,259 Asset retirement obligation 34,653 6,489 — — 41,142 Long-term debt, net of current maturities 1,631,809 — — — 1,631,809 Total liabilities 2,100,727 534,030 127 (482,709 ) 2,152,175 Stockholders’ equity: Common stock 1,828 — — — 1,828 Paid-in capital 4,408,236 1,872,598 257,700 (2,130,298 ) 4,408,236 Accumulated other comprehensive (loss) income (51,685 ) — (49,613 ) 49,613 (51,685 ) Retained (deficit) earnings (1,556,625 ) 38,010 (161,375 ) 123,365 (1,556,625 ) Total stockholders’ equity 2,801,754 1,910,608 46,712 (1,957,320 ) 2,801,754 Total liabilities and stockholders ’ equity $ 4,902,481 $ 2,444,638 $ 46,839 $ (2,440,029 ) $ 4,953,929 CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) December 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 1,273,882 $ 1,993 $ — $ — $ 1,275,875 Restricted Cash 185,000 — — — $ 185,000 Accounts receivable - oil and gas 137,087 37,496 — (37,822 ) 136,761 Accounts receivable - related parties 16 — — — 16 Accounts receivable - intercompany 449,517 1,151 — (450,668 ) — Prepaid expenses and other current assets 6,230 1,409 — — 7,639 Short-term derivative instruments 3,488 — — — 3,488 Total current assets 2,055,220 42,049 — (488,490 ) 1,608,779 Property and equipment: Oil and natural gas properties, full-cost accounting, 5,655,125 417,524 — (729 ) 6,071,920 Other property and equipment 68,943 43 — — 68,986 Accumulated depletion, depreciation, amortization and impairment (3,789,746 ) (34 ) — — (3,789,780 ) Property and equipment, net 1,934,322 417,533 — (729 ) 2,351,126 Other assets: Equity investments and investments in subsidiaries 236,327 33,590 45,213 (71,210 ) 243,920 Long-term derivative instruments 5,696 — — — 5,696 Deferred tax asset 4,692 — — — 4,692 Other assets 8,932 — — — 8,932 Total other assets 255,647 33,590 45,213 (71,210 ) 263,240 Total assets $ 4,245,189 $ 493,172 $ 45,213 $ (560,429 ) $ 4,223,145 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 255,966 $ 9,158 $ — $ — $ 265,124 Accounts payable - intercompany 31,202 457,163 126 (488,491 ) — Asset retirement obligation 195 — — — 195 Derivative instruments 119,219 — — — 119,219 Current maturities of long-term debt 276 — — — 276 Total current liabilities 406,858 466,321 126 (488,491 ) 384,814 Long-term derivative instrument 26,759 — — — 26,759 Asset retirement obligation 34,081 — — — 34,081 Long-term debt, net of current maturities 1,593,599 — — — 1,593,599 Total liabilities 2,061,297 466,321 126 (488,491 ) 2,039,253 Stockholders’ equity: Common stock 1,588 — — — 1,588 Paid-in capital 3,946,442 33,822 257,026 (290,848 ) 3,946,442 Accumulated other comprehensive (loss) income (53,058 ) — (50,931 ) 50,931 (53,058 ) Retained (deficit) earnings (1,711,080 ) (6,971 ) (161,008 ) 167,979 (1,711,080 ) Total stockholders’ equity 2,183,892 26,851 45,087 (71,938 ) 2,183,892 Total liabilities and stockholders ’ equity $ 4,245,189 $ 493,172 $ 45,213 $ (560,429 ) $ 4,223,145 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 272,441 $ 60,563 $ — $ — $ 333,004 Costs and expenses: Lease operating expenses 17,449 1,854 — — 19,303 Production taxes 3,102 804 — — 3,906 Midstream gathering and processing 37,724 10,217 — — 47,941 Depreciation, depletion, and amortization 65,990 1 — — 65,991 General and administrative 12,874 (275 ) 1 — 12,600 Accretion expense 282 — — — 282 Acquisition expense — 1,298 — — 1,298 137,421 13,899 1 — 151,321 INCOME (LOSS) FROM OPERATIONS 135,020 46,664 (1 ) — 181,683 OTHER (INCOME) EXPENSE: Interest expense 25,048 (1,569 ) — — 23,479 Interest income (842 ) — — — (842 ) (Income) loss from equity method investments and investments in subsidiaries (42,614 ) 2,541 365 44,615 4,907 Other (income) expense (1,027 ) (189 ) — 900 (316 ) (19,435 ) 783 365 45,515 27,228 INCOME (LOSS) BEFORE INCOME TAXES 154,455 45,881 (366 ) (45,515 ) 154,455 INCOME TAX EXPENSE — — — — — NET INCOME (LOSS) $ 154,455 $ 45,881 $ (366 ) $ (45,515 ) $ 154,455 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended March 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 156,751 $ 210 $ — $ — $ 156,961 Costs and expenses: Lease operating expenses 16,472 185 — — 16,657 Production taxes 3,087 24 — — 3,111 Midstream gathering and processing 37,623 29 — — 37,652 Depreciation, depletion, and amortization 65,476 1 — — 65,477 Impairment of oil and gas properties 218,991 — — — 218,991 General and administrative 10,612 6 2 — 10,620 Accretion expense 247 — — — 247 352,508 245 2 — 352,755 LOSS FROM OPERATIONS (195,757 ) (35 ) (2 ) — (195,794 ) OTHER (INCOME) EXPENSE: Interest expense 16,022 1 — — 16,023 Interest income (94 ) — — — (94 ) Loss (income) from equity method investments and investments in subsidiaries 30,773 — 23,685 (23,721 ) 30,737 Other income — (2 ) — — (2 ) 46,701 (1 ) 23,685 (23,721 ) 46,664 (LOSS) INCOME BEFORE INCOME TAXES (242,458 ) (34 ) (23,687 ) 23,721 (242,458 ) INCOME TAX BENEFIT (191 ) (191 ) NET (LOSS) INCOME $ (242,267 ) $ (34 ) $ (23,687 ) $ 23,721 $ (242,267 ) CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Amounts in thousands) Three months ended March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 154,455 $ 45,881 $ (366 ) $ (45,515 ) $ 154,455 Foreign currency translation adjustment 1,373 55 1,318 (1,373 ) 1,373 Other comprehensive income (loss) 1,373 55 1,318 (1,373 ) 1,373 Comprehensive income (loss) $ 155,828 $ 45,936 $ 952 $ (46,888 ) $ 155,828 Three months ended March 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net (loss) income $ (242,267 ) $ (34 ) $ (23,687 ) $ 23,721 $ (242,267 ) Foreign currency translation adjustment 9,058 — 10,273 (10,273 ) 9,058 Other comprehensive income (loss) 9,058 — 10,273 (10,273 ) 9,058 Comprehensive (loss) income $ (233,209 ) $ (34 ) $ (13,414 ) $ 13,448 $ (233,209 ) CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Amounts in thousands) Three months ended March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 139,260 $ 3,384 $ 1 $ — $ 142,645 Net cash (used in) provided by investing activities (1,372,852 ) (1,348,964 ) (673 ) 1,374,810 (1,347,679 ) Net cash provided by (used in) financing activities 31,644 1,374,137 673 (1,374,810 ) 31,644 Net (decrease) increase in cash and cash equivalents (1,201,948 ) 28,557 1 — (1,173,390 ) Cash and cash equivalents at beginning of period 1,273,882 1,993 — — 1,275,875 Cash and cash equivalents at end of period $ 71,934 $ 30,550 $ 1 $ — $ 102,485 Three months ended March 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 83,620 $ 155 $ (1 ) $ — $ 83,774 Net cash (used in) provided by investing activities (157,529 ) (22,500 ) (1,821 ) 24,321 (157,529 ) Net cash provided by (used in) financing activities 415,158 22,500 1,821 (24,321 ) 415,158 Net increase (decrease) in cash and cash equivalents 341,249 155 (1 ) — 341,403 Cash and cash equivalents at beginning of period 112,494 479 1 — 112,974 Cash and cash equivalents at end of period $ 453,743 $ 634 $ — $ — $ 454,377

Recent Accounting Pronouncement

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which supersedes the revenue recognition requirements in Topic 605, Revenue Recognition , and most industry-specific guidance. The core principle of the new standard is for the recognition of revenue to depict the transfer of goods or services to customers in amounts that reflect the payment to which the company expects to be entitled in exchange for those goods or services. The new standard will also result in enhanced revenue disclosures, provide guidance for transactions that were not previously addressed comprehensively and improve guidance for multiple-element arrangements. The ASU is effective for annual periods beginning after December 15, 2016, and interim periods within those years, using either a full or a modified retrospective application approach. In July 2015, the FASB decided to defer the effective date by one year (until 2018). The Company is evaluating the impact of this ASU on its consolidated financial statements, and based on the continuing evaluation of its revenue streams, this ASU is not expected to have a material impact on its net income. The Company is still in the process of determining whether or not it will use the retrospective method or the modified retrospective approach to implementation. In February 2016, the FASB issued ASU No. 2016-02, Leases . The guidance requires the lessee to recognize most leases on the balance sheet thereby resulting in the recognition of lease assets and liability for those leases currently classified as operating leases. The accounting for lessors is largely unchanged. The guidance is effective for periods after December 15, 2018, with early adoption permitted. The Company is in the process of evaluating the impact of this guidance on its consolidated financial statements and related disclosures; however, based on the Company’s current operating leases, it is not expected to have a material impact. In March 2016, the FASB issued ASU No. 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships. The guidance was issued to clarify that change in the counterparty to a derivative instrument that had been designated as the hedging instrument under Topic 815, does not require designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company adopted the standard as of January 1, 2017. There was no impact on the Company’s consolidated financial statements because all current derivative instruments are not designated for hedge accounting. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting . This guidance was intended to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The Company adopted the standard as of January 1, 2017. The Company has elected to recognize forfeitures of awards as they occur. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. In May 2016, the FASB issued ASU No. 2016-11, Revenue Recognition and Derivatives and Hedging: Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting. This guidance rescinds SEC Staff Observer comments that are codified in Topic 606, Revenue Recognition, and Topic 932, Extractive Activities--Oil and Gas. This amendment is effective upon adoption of Topic 606. The Company is in the process of evaluating the impact of this guidance on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments . This ASU amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. For assets held at amortized cost basis, this ASU eliminates the probable initial recognition threshold in current GAAP and instead, requires an entity to reflect its current estimate of all expected credit losses. The amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposure, reinsurance receivables and any other financial assets not excluded from the scope that have the contractual right to receive cash. The Company is currently evaluating the impact this standard will have on its financial statements and related disclosures and does not anticipate it to have a material affect. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments. This ASU provides guidance of eight specific cash flow issues. This ASU is effective for periods after December 15, 2017, with early adoption permitted. The Company is in the process of evaluating the impact of this guidance on its consolidated financial statements. In December 2016, the FASB issued ASU No. 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers . This guidance updates narrow aspects of the guidance issued in Update 2014-09. This amendment is effective for periods after December 15, 2017, with early adoption permitted. The Company is in the process of evaluating the impact of this ASU on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business . Under the current business combination guidance, there are three elements of a business: inputs, processes and outputs. The revised guidance adds an initial screen test to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single asset or group of similar assets. If that screen is met, the set of assets is not a business. The new framework also specifies the minimum required inputs and processes necessary to be a business. This amendment is effective for periods after December 15, 2017, with early adoption permitted. The Company is in the process of evaluating the impact of this ASU on its consolidated financial statements.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Derivatives In April 2017, the Company entered into fixed price swaps for 2018 for approximately 65,000 MMBtu of natural gas per day at a weighted average price of $3.03 per MMBtu. For 2019, the Company entered into fixed price swaps for approximately 10,000 MMBtu of natural gas per day at a weighted average price of $3.01 per MMBtu. The Company’s fixed price swap contracts are tied to the commodity prices on NYMEX. The Company will receive the fixed price amount stated in the contract and pay to its counterparty the current market price as listed on NYMEX for natural gas. Mammoth Energy Pending Acquisitions In March 2017, Mammoth Energy entered into definitive agreements to acquire Sturgeon (which owns Taylor Frac, LLC, Taylor Real Estate Investments, LLC and South River Road, LLC), Stingray Energy and Stingray Cementing from the owners of such companies, including Gulfport, for an aggregate of 7.0 million shares of Mammoth Energy common stock. Mammoth Energy anticipates the transactions will close in the second quarter of 2017, subject to agreed closing conditions. Upon closing, the Company will receive approximately 2.0 million shares of Mammoth Energy common stock and hold approximately 25.1% of Mammoth Energy’s outstanding common stock.

Recent Accounting Pronounceme23

Recent Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Variable Interest Entities	The Company accounts for its investment in these VIEs following the equity method of accounting. The carrying amounts of the Company’s equity investments are classified as other non-current assets on the accompanying consolidated balance sheets. The Company’s maximum exposure to loss as a result of its involvement with these VIEs is based on the Company’s capital contributions and the economic performance of the VIEs, and is equal to the carrying value of the Company’s investments which is the maximum loss the Company could be required to record in the consolidated statements of operations. See Note 3 for further discussion of these entities, including the carrying amounts of each investment.
Recent Accounting Pronouncements	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which supersedes the revenue recognition requirements in Topic 605, Revenue Recognition , and most industry-specific guidance. The core principle of the new standard is for the recognition of revenue to depict the transfer of goods or services to customers in amounts that reflect the payment to which the company expects to be entitled in exchange for those goods or services. The new standard will also result in enhanced revenue disclosures, provide guidance for transactions that were not previously addressed comprehensively and improve guidance for multiple-element arrangements. The ASU is effective for annual periods beginning after December 15, 2016, and interim periods within those years, using either a full or a modified retrospective application approach. In July 2015, the FASB decided to defer the effective date by one year (until 2018). The Company is evaluating the impact of this ASU on its consolidated financial statements, and based on the continuing evaluation of its revenue streams, this ASU is not expected to have a material impact on its net income. The Company is still in the process of determining whether or not it will use the retrospective method or the modified retrospective approach to implementation. In February 2016, the FASB issued ASU No. 2016-02, Leases . The guidance requires the lessee to recognize most leases on the balance sheet thereby resulting in the recognition of lease assets and liability for those leases currently classified as operating leases. The accounting for lessors is largely unchanged. The guidance is effective for periods after December 15, 2018, with early adoption permitted. The Company is in the process of evaluating the impact of this guidance on its consolidated financial statements and related disclosures; however, based on the Company’s current operating leases, it is not expected to have a material impact. In March 2016, the FASB issued ASU No. 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships. The guidance was issued to clarify that change in the counterparty to a derivative instrument that had been designated as the hedging instrument under Topic 815, does not require designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The Company adopted the standard as of January 1, 2017. There was no impact on the Company’s consolidated financial statements because all current derivative instruments are not designated for hedge accounting. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting . This guidance was intended to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The Company adopted the standard as of January 1, 2017. The Company has elected to recognize forfeitures of awards as they occur. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. In May 2016, the FASB issued ASU No. 2016-11, Revenue Recognition and Derivatives and Hedging: Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting. This guidance rescinds SEC Staff Observer comments that are codified in Topic 606, Revenue Recognition, and Topic 932, Extractive Activities--Oil and Gas. This amendment is effective upon adoption of Topic 606. The Company is in the process of evaluating the impact of this guidance on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments . This ASU amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. For assets held at amortized cost basis, this ASU eliminates the probable initial recognition threshold in current GAAP and instead, requires an entity to reflect its current estimate of all expected credit losses. The amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposure, reinsurance receivables and any other financial assets not excluded from the scope that have the contractual right to receive cash. The Company is currently evaluating the impact this standard will have on its financial statements and related disclosures and does not anticipate it to have a material affect. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments. This ASU provides guidance of eight specific cash flow issues. This ASU is effective for periods after December 15, 2017, with early adoption permitted. The Company is in the process of evaluating the impact of this guidance on its consolidated financial statements. In December 2016, the FASB issued ASU No. 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers . This guidance updates narrow aspects of the guidance issued in Update 2014-09. This amendment is effective for periods after December 15, 2017, with early adoption permitted. The Company is in the process of evaluating the impact of this ASU on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business . Under the current business combination guidance, there are three elements of a business: inputs, processes and outputs. The revised guidance adds an initial screen test to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single asset or group of similar assets. If that screen is met, the set of assets is not a business. The new framework also specifies the minimum required inputs and processes necessary to be a business. This amendment is effective for periods after December 15, 2017, with early adoption permitted. The Company is in the process of evaluating the impact of this ASU on its consolidated financial statements.

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes the consideration paid in the Vitruvian Acquisition to acquire the properties and the fair value amount of the assets acquired as of February 17, 2017. Both the consideration paid and the fair value assigned to the assets is preliminary and subject to adjustment. (In thousands) Consideration: Cash, net of purchase price adjustments $ 1,354,093 Fair value of Gulfport’s common stock issued 464,639 Total Consideration $ 1,818,732 Estimated Fair value of identifiable assets acquired and liabilities assumed: Oil and natural gas properties Proved properties $ 362,264 Unproved properties 1,462,957 Asset retirement obligations (6,489 ) Total fair value of net identifiable assets acquired $ 1,818,732
Schedule of Pro Forma Information	For the period from the acquisition date of February 17, 2017 to March 31, 2017 , the assets acquired in the Vitruvian Acquisition have contributed the following amounts of revenue to the Company’s consolidated statements of operations. The amount of net income contributed by the assets acquired is not presented below as it is impracticable to calculate due to the Company integrating the acquired assets into its overall operations using the full cost method of accounting. (In thousands) Revenue $ 26,226 Pro Forma Information (Unaudited) The following unaudited pro forma combined financial information presents the Company’s results as though the Vitruvian Acquisition had been completed at January 1, 2016. The pro forma combined financial information has been included for comparative purposes and is not necessarily indicative of the results that might have actually occurred had the Vitruvian Acquisition taken place on January 1, 2016; furthermore, the financial information is not intended to be a projection of future results. Three months ended March 31, 2017 2016 (In thousands, except share data) Pro forma revenue $ 368,903 $ 203,712 Pro forma net income (loss) $ 175,881 $ (274,207 ) Pro forma earnings (loss) per share (basic) $ 1.03 $ (2.03 ) Pro forma earnings (loss) per share (diluted) $ 1.03 $ (2.03 )

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	The major categories of property and equipment and related accumulated depletion, depreciation, amortization and impairment as of March 31, 2017 and December 31, 2016 are as follows: March 31, 2017 December 31, 2016 (In thousands) Oil and natural gas properties $ 8,146,321 $ 6,071,920 Office furniture and fixtures 24,649 21,204 Building 45,204 42,530 Land 5,254 5,252 Total property and equipment 8,221,428 6,140,906 Accumulated depletion, depreciation, amortization and impairment (3,855,629 ) (3,789,780 ) Property and equipment, net $ 4,365,799 $ 2,351,126
Summary of Oil and Gas Properties Not Subject to Amortization	The following table summarizes the Company’s non-producing properties excluded from amortization by area at March 31, 2017 : March 31, 2017 (In thousands) Utica $ 1,592,683 MidCon 1,477,643 Niobrara 2,172 Southern Louisiana 484 Bakken 98 Other 368 $ 3,073,448
Schedule of Asset Retirement Obligation	A reconciliation of the Company’s asset retirement obligation for the three months ended March 31, 2017 and 2016 is as follows: March 31, 2017 March 31, 2016 (In thousands) Asset retirement obligation, beginning of period $ 34,276 $ 26,437 Liabilities incurred 6,779 1,914 Liabilities settled — (52 ) Accretion expense 282 247 Asset retirement obligation as of end of period 41,337 28,546 Less current portion 195 75 Asset retirement obligation, long-term $ 41,142 $ 28,471

Equity Investments (Tables)

Equity Investments (Tables)	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments Accounted for by the Equity Method	Investments accounted for by the equity method consist of the following as of March 31, 2017 and December 31, 2016 : Carrying value (Income) loss from equity method investments Approximate ownership % March 31, 2017 December 31, 2016 Three months ended March 31, 2017 2016 (In thousands) Investment in Tatex Thailand II, LLC 23.5 % $ — $ — $ (243 ) $ (159 ) Investment in Tatex Thailand III, LLC 17.9 % — — — — Investment in Grizzly Oil Sands ULC 24.9999 % 46,838 45,213 365 23,685 Investment in Timber Wolf Terminals LLC 50.0 % 987 991 4 3 Investment in Windsor Midstream LLC 22.5 % 25,815 25,749 (311 ) (167 ) Investment in Stingray Cementing LLC 50.0 % 1,768 1,920 128 30 Investment in Blackhawk Midstream LLC 48.5 % — — — — Investment in Stingray Energy Services LLC 50.0 % 3,967 4,215 197 502 Investment in Sturgeon Acquisitions LLC 25.0 % 20,458 20,526 68 377 Investment in Mammoth Energy Services, Inc. 24.2 % 110,875 111,717 2,158 6,466 Investment in Strike Force Midstream LLC 25.0 % 40,662 33,589 2,541 — $ 251,370 $ 243,920 $ 4,907 $ 30,737
Equity Method Investment Balance Sheet Summary	The tables below summarize financial information for the Company’s equity investments as of March 31, 2017 and December 31, 2016 . Summarized balance sheet information: March 31, 2017 December 31, 2016 (In thousands) Current assets $ 151,587 $ 148,733 Noncurrent assets $ 1,342,012 $ 1,305,407 Current liabilities $ 97,329 $ 57,173 Noncurrent liabilities $ 59,721 $ 67,680
Equity Method Investment Income Statement Summary	Summarized results of operations: Three months ended March 31, 2017 2016 (In thousands) Gross revenue $ 94,478 $ 43,307 Net loss $ (25,339 ) $ (25,308 )

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Long-term Debt, Unclassified [Abstract]
Break-Down of Long-Term Debt	Long-term debt consisted of the following items as of March 31, 2017 and December 31, 2016 : March 31, 2017 December 31, 2016 (In thousands) Revolving credit agreement (1) $ 40,000 $ — 7.75% senior unsecured notes due 2020 (2) — — 6.625% senior unsecured notes due 2023 (3) 350,000 350,000 6.000% senior unsecured notes due 2024 (4) 650,000 650,000 6.375% senior unsecured notes due 2025 (5) 600,000 600,000 Net unamortized debt issuance costs (6) (31,486 ) (27,174 ) Construction loan (7) 23,747 21,049 Less: current maturities of long term debt (452 ) (276 ) Debt reflected as long term $ 1,631,809 $ 1,593,599 The Company capitalized approximately $3.1 million and $1.6 million in interest expense to undeveloped oil and natural gas properties during the three months ended March 31, 2017 and 2016 , respectively. During the three months ended March 31, 2016, the Company capitalized $0.3 million in interest expense related to building construction. Construction on the building was completed in December 2016 and, as such, the Company did not capitalize any interest expense related to building construction for the three months ended March 31, 2017 . (1) The Company has entered into a senior secured revolving credit facility, as amended, with The Bank of Nova Scotia, as the lead arranger and administrative agent and certain lenders from time to time party thereto. The credit agreement provides for a maximum facility amount of $1.5 billion and matures on June 6, 2018. On December 13, 2016, the Company further amended its revolving credit facility to, among other things, (a) reset the maturity date to December 31, 2021, (b) adjust lenders, (c) increase the basket for unsecured debt issuances to $1.6 billion , (d) increase the interest rates by 50 basis points, (e) increase the mortgage requirement to 85% (from 80% ), and (f) add deposit account control agreement language. On March 29, 2017, the Company further amended its revolving credit facility to, among other things, amend the definition of the term EBITDAX to permit pro forma treatment of acquisitions that involve the payment of consideration by Gulfport and its subsidiaries in excess of $50.0 million and of dispositions of property or series of related dispositions of properties that yields gross proceeds to Gulfport or any of its subsidiaries in excess of $50.0 million . As of March 31, 2017 , the borrowing base was set at $700.0 million and $40.0 million was outstanding under the revolving credit facility. At March 31, 2017 , the total availability for future borrowings under the revolving credit facility, after giving effect to an aggregate of $238.7 million of letters of credit, was $421.3 million . The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. On May 4, 2017, the revolving credit facility was further amended to increase the borrowing base from $700.0 million to $1.0 billion , adjust certain of the Company's investment baskets and add five additional banks to the syndicate. Advances under the revolving credit facility may be in the form of either base rate loans or eurodollar loans. The interest rate for base rate loans is equal to (1) the applicable rate, which ranges from 1.00% to 2.00% , plus (2) the highest of: (a) the federal funds rate plus 0.50% , (b) the rate of interest in effect for such day as publicly announced from time to time by agent as its “prime rate,” and (c) the eurodollar rate for an interest period of one month plus 1.00% . The interest rate for eurodollar loans is equal to (1) the applicable rate, which ranges from 2.00% to 3.00% , plus (2) the London interbank offered rate that appears on pages LIBOR01 or LIBOR02 of the Reuters screen that displays such rate for deposits in U.S. dollars, or, if such rate is not available, the rate as administered by ICE Benchmark Administration (or any other person that takes over administration of such rate) per annum equal to the offered rate on such other page or service that displays on average London interbank offered rate as determined by ICE Benchmark Administration (or any other person that takes over administration of such rate) for deposits in U.S. dollars, or, if such rate is not available, the average quotations for three major New York money center banks of whom the agent shall inquire as the “London Interbank Offered Rate” for deposits in U.S. dollars. At March 31, 2107, amounts borrowed under the credit facility bore interest at the eurodollar rate ( 3.18% ). The revolving credit facility contains customary negative covenants including, but not limited to, restrictions on the Company’s and its subsidiaries’ ability to: • incur indebtedness; • grant liens; • pay dividends and make other restricted payments; • make investments; • make fundamental changes; • enter into swap contracts and forward sales contracts; • dispose of assets; • change the nature of their business; and • enter into transactions with affiliates. The negative covenants are subject to certain exceptions as specified in the revolving credit facility. The revolving credit facility also contains certain affirmative covenants, including, but not limited to the following financial covenants: (i) the ratio of net funded debt to EBITDAX (net income, excluding (i) any non-cash revenue or expense associated with swap contracts resulting from ASC 815 and (ii) any cash or non-cash revenue or expense attributable to minority investments plus without duplication and, in the case of expenses, to the extent deducted from revenues in determining net income, the sum of (a) the aggregate amount of consolidated interest expense for such period, (b) the aggregate amount of income, franchise, capital or similar tax expense (other than ad valorem taxes) for such period, (c) all amounts attributable to depletion, depreciation, amortization and asset or goodwill impairment or writedown for such period, (d) all other non-cash charges, (e) exploration costs deducted in determining net income under successful efforts accounting, (f) actual cash distributions received from minority investments, (g) to the extent actually reimbursed by insurance, expenses with respect to liability on casualty events or business interruption, and (h) all reasonable transaction expenses related to dispositions and acquisitions of assets, investments and debt and equity offerings (provided that expenses related to any unsuccessful disposition will be limited to $3.0 million in the aggregate) for a twelve-month period may not be greater than 4.00 to 1.00 ; and (ii) the ratio of EBITDAX to interest expense for a twelve-month period may not be less than 3.00 to 1.00 . The Company was in compliance with all covenants at March 31, 2017 . (2) On October 17, 2012, the Company issued $250.0 million in aggregate principal amount of 7.75% Senior Notes due 2020 (the “October Notes”) under an indenture among the Company, its subsidiary guarantors and Wells Fargo Bank, National Association, as the trustee (the “senior note indenture”). On December 21, 2012, the Company issued an additional $50.0 million in aggregate principal amount of 7.75% Senior Notes due 2020 (the “December Notes”) as additional securities under the senior note indenture. On August 18, 2014, the Company issued an additional $300.0 million in aggregate principal amount of 7.75% Senior Notes due 2020 (the “August Notes”). The August Notes were issued as additional securities under the senior note indenture. The October Notes, December Notes and the August Notes are collectively referred to as the “2020 Notes.” In October 2016 , the Company repurchased (in a cash tender offer) or redeemed all of the 2020 Notes, of which $600.0 million in aggregate principal amount was then outstanding, with the net proceeds from the issuance of its 6.000% Senior Notes due 2024 (the “2024 Notes”) discussed below and cash on hand, and the indenture governing the 2020 Notes was fully satisfied and discharged. (3) On April 21, 2015, the Company issued $350.0 million in aggregate principal amount of 6.625% Senior Notes due 2023 (the “2023 Notes”) to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2023 Notes Offering”). The Company received net proceeds of approximately $343.6 million after initial purchaser discounts and commissions and estimated offering expenses. The 2023 Notes were issued under an indenture, dated as of April 21, 2015, among the Company, the subsidiary guarantors party thereto and Wells Fargo Bank, National Association, as trustee. In October 2015, the 2023 Notes were exchanged for a new issue of substantially identical debt securities registered under the Securities Act. Pursuant to the indenture relating to the 2023 Notes, interest on the 2023 Notes will accrue at a rate of 6.625% per annum on the outstanding principal amount thereof from April 21, 2015, payable semi-annually on May 1 and November 1 of each year, commencing on November 1, 2015. The 2023 Notes are not guaranteed by Grizzly Holdings, Inc. and will not be guaranteed by any of the Company’s future unrestricted subsidiaries. (4) On October 14, 2016, the Company issued the 2024 Notes in aggregate principal amount of $650.0 million . The 2024 Notes were issued under an indenture, dated as of October 14, 2016, among the Company, the subsidiary guarantors party thereto and the senior note indenture trustee (the “2024 Indenture”), to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2024 Notes Offering”). Under the 2024 Indenture, interest on the 2024 Notes accrues at a rate of 6.000% per annum on the outstanding principal amount thereof from October 14, 2016, payable semi-annually on April 15 and October 15 of each year, commencing on April 15, 2017. The 2024 Notes will mature on October 15, 2024. The Company received approximately $638.9 million in net proceeds from the offering of the 2024 Notes, which was used, together with cash on hand, to purchase the outstanding 2020 Notes in a concurrent cash tender offer, to pay fees and expenses thereof, and to redeem any of the 2020 Notes that remained outstanding after the completion of the tender offer. (5) On December 21, 2016, the Company issued $600.0 million in aggregate principal amount of 6.375% Senior Notes due 2025 (the “2025 Notes”). The 2025 Notes were issued under an indenture, dated as of December 21, 2016, among the Company, the subsidiary guarantors party thereto and the senior note indenture trustee (the “2025 Indenture”), to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, and to certain non-U.S. persons in accordance with Regulation S under the Securities Act. Under the 2025 Indenture, interest on the 2025 Notes accrues at a rate of 6.375% per annum on the outstanding principal amount thereof from December 21, 2016, payable semi-annually on May 15 and November 15 of each year, commencing on May 15, 2017. The 2025 Notes will mature on May 15, 2025. The Company received approximately $584.7 million in net proceeds from the offering of the 2025 Notes, which was used, together with the net proceeds from the Company’s December 2016 common stock offering and cash on hand, to fund the cash portion of the purchase price for the Vitruvian Acquisition. See “Note 1 – Acquisitions” for additional discussion of the Vitruvian Acquisition. (6) In accordance with ASU 2015-03, loan issuance costs related to the 2023 Notes, the 2024 Notes and the 2025 Notes (collectively the “Notes”) have been presented as a reduction to the Notes. At March 31, 2017 , total unamortized debt issuance costs were $5.8 million for the 2023 Notes, $10.7 million for the 2024 Notes and $14.9 million for the 2025 Notes. In addition, loan commitment fee costs for the construction loan agreement described immediately below were $0.1 million at March 31, 2017 . (7) On June 4, 2015, the Company entered into a construction loan agreement (the “Construction Loan”) with InterBank for the construction of a new corporate headquarters in Oklahoma City, which was substantially completed in December 2016. The Construction Loan allows for maximum principal borrowings of $24.5 million and required the Company to fund 30% of the cost of the construction before any funds could be drawn, which occurred in January 2016. Interest accrues daily on the outstanding principal balance at a fixed rate of 4.50% per annum and is payable on the last day of the month through May 31, 2017. Monthly interest and principal payments are due beginning June 30, 2017, with the final payment due June 4, 2025. At March 31, 2017 , the total borrowings under the Construction Loan were approximately $23.7 million .

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2017
Share-based Compensation [Abstract]
Summary of Restricted Stock Award and Unit Activity	The following table summarizes restricted stock activity for the three months ended March 31, 2017 : Number of Unvested Restricted Shares Weighted Average Grant Date Fair Value Unvested shares as of January 1, 2017 613,056 $ 32.90 Granted 477,768 17.74 Vested (153,868 ) 31.98 Forfeited (65,438 ) 31.23 Unvested shares as of March 31, 2017 871,518 $ 24.88

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share Reconciliation	Reconciliations of the components of basic and diluted net income (loss) per common share are presented in the tables below: Three months ended March 31, 2017 2016 Income Shares Per Share (Loss) Shares Per Share (In thousands, except share data) Basic: Net income (loss) $ 154,455 170,272,685 $ 0.91 $ (242,267 ) 111,509,585 $ (2.17 ) Effect of dilutive securities: Stock options and awards — 215,834 — — Diluted: — Net income (loss) $ 154,455 170,488,519 $ 0.91 $ (242,267 ) 111,509,585 $ (2.17 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2017
Long-term Purchase Commitment [Line Items]
Schedule of Future Minimum Lease Commitments	Future minimum lease commitments under these leases at March 31, 2017 were as follows: (In thousands) Remaining 2017 $ 129 2018 54 Total $ 183
Schedule of Firm Transportation Commitments	The table below presents these commitments at March 31, 2017 as follows: (MMBtu per day) Remaining 2017 725,625 2018 457,000 2019 604,750 2020 518,000 2021 371,000 Thereafter 276,000 Total 2,952,375
Transportation commitment
Long-term Purchase Commitment [Line Items]
Schedule of Other Commitments	The table below presents these commitments at March 31, 2017 as follows: (In thousands) Remaining 2017 $ 143,816 2018 241,709 2019 241,708 2020 240,746 2021 239,786 Thereafter 2,705,270 Total $ 3,813,035
Purchase commitment
Long-term Purchase Commitment [Line Items]
Schedule of Other Commitments	Future minimum commitments under these agreements at March 31, 2017 are as follows: (In thousands) Remaining 2017 $ 39,330 2018 39,330 Total $ 78,660

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2017
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Schedule of Open Fixed Price Swap Positions	Below is a summary of the Company’s open fixed price swap positions as of March 31, 2017 . Location Daily Volume (MMBtu/day) Weighted Remaining 2017 NYMEX Henry Hub 576,845 $ 3.18 2018 NYMEX Henry Hub 543,767 $ 3.09 2019 NYMEX Henry Hub 9,863 $ 3.27 Location Daily Volume Weighted Remaining 2017 ARGUS LLS 1,665 $ 52.32 Remaining 2017 NYMEX WTI 4,113 $ 54.97 2018 NYMEX WTI 899 $ 55.31 Location Daily Volume Weighted Remaining 2017 Mont Belvieu C3 3,000 $ 26.63 Remaining 2017 Mont Belvieu C5 250 $ 49.14 The Company sold call options and used the associated premiums to enhance the fixed price for a portion of the fixed price natural gas swaps listed above. Each short call option has an established ceiling price. When the referenced settlement price is above the price ceiling established by these short call options, the Company pays its counterparty an amount equal to the difference between the referenced settlement price and the price ceiling multiplied by the hedged contract volumes. Location Daily Volume (MMBtu/day) Weighted Average Price Remaining 2017 NYMEX Henry Hub 65,000 $ 3.11 2018 NYMEX Henry Hub 80,000 $ 3.29 2019 NYMEX Henry Hub 4,932 $ 3.16
Schedule of Natural Gas Basis Swap Position Derivatives	As of March 31, 2017 , the Company had the following natural gas basis swap positions for NGPL Mid-Continent. Location Daily Volume (MMBtu/day) Hedged Differential Remaining 2017 NGPL Mid-Continent 50,000 $ (0.26 ) 2018 NGPL Mid-Continent 12,329 $ (0.26 )
Schedule of Derivative Instruments In Statement Of Financial Position	The following table presents the fair value of the Company’s derivative instruments on a gross basis at March 31, 2017 and December 31, 2016 : March 31, 2017 December 31, 2016 (In thousands) Short-term derivative instruments - asset $ 18,925 $ 3,488 Long-term derivative instruments - asset $ 23,515 $ 5,696 Short-term derivative instruments - liability $ 67,179 $ 119,219 Long-term derivative instruments - liability $ 5,259 $ 26,759
Schedule of Cash Flow Hedges	The following table presents the gain and loss recognized in Net gain on gas, oil and NGL derivatives in the accompanying consolidated statements of operations for the three months ended March 31, 2017 and 2016 . Net gain (loss) on derivative instruments Three months ended March 31, 2017 2016 (In thousands) Natural gas derivatives $ 86,277 $ 57,000 Oil derivatives 10,905 1,282 Natural gas liquids derivatives 2,395 (547 ) Total $ 99,577 $ 57,735
Recognized Derivative Assets	The following table presents the gross amounts of recognized derivative assets and liabilities in the consolidated balance sheets and the amounts that are subject to offsetting under master netting arrangements with counterparties, all at fair value. As of March 31, 2017 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 42,440 $ (41,180 ) $ 1,260 Derivative liabilities $ (72,438 ) $ 41,180 $ (31,258 ) As of December 31, 2016 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 9,184 $ (9,184 ) $ — Derivative liabilities $ (145,978 ) $ 9,184 $ (136,794 )
Recognized Derivative Liabilities	The following table presents the gross amounts of recognized derivative assets and liabilities in the consolidated balance sheets and the amounts that are subject to offsetting under master netting arrangements with counterparties, all at fair value. As of March 31, 2017 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 42,440 $ (41,180 ) $ 1,260 Derivative liabilities $ (72,438 ) $ 41,180 $ (31,258 ) As of December 31, 2016 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 9,184 $ (9,184 ) $ — Derivative liabilities $ (145,978 ) $ 9,184 $ (136,794 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	The following tables summarize the Company’s financial and non-financial assets and liabilities by FASB ASC 820 valuation level as of March 31, 2017 and December 31, 2016 : March 31, 2017 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 42,440 $ — Liabilities: Derivative Instruments $ — $ 72,438 $ — December 31, 2016 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 9,184 $ — Liabilities: Derivative Instruments $ — $ 145,978 $ —

Condensed Consolidating Finan33

Condensed Consolidating Financial Information (Tables)	3 Months Ended
	Mar. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Balance Sheets	CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 71,934 $ 30,550 $ 1 $ — $ 102,485 Accounts receivable - oil and gas 106,008 52,146 — — 158,154 Accounts receivable - related parties 39 — — — 39 Accounts receivable - intercompany 447,275 35,434 — (482,709 ) — Prepaid expenses and other current assets 12,330 3,675 — — 16,005 Short-term derivative instruments 18,925 — — — 18,925 Total current assets 656,511 121,805 1 (482,709 ) 295,608 Property and equipment: Oil and natural gas properties, full-cost accounting 5,869,066 2,277,984 — (729 ) 8,146,321 Other property and equipment 75,064 43 — — 75,107 Accumulated depletion, depreciation, amortization and impairment (3,855,594 ) (35 ) — — (3,855,629 ) Property and equipment, net 2,088,536 2,277,992 — (729 ) 4,365,799 Other assets: Equity investments and investments in subsidiaries 2,120,462 40,661 46,838 (1,956,591 ) 251,370 Long-term derivative instruments 23,515 — — — 23,515 Deferred tax asset 4,692 — — — 4,692 Other assets 8,765 4,180 — — 12,945 Total other assets 2,157,434 44,841 46,838 (1,956,591 ) 292,522 Total assets $ 4,902,481 $ 2,444,638 $ 46,839 $ (2,440,029 ) $ 4,953,929 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 326,175 $ 79,964 $ — $ — $ 406,139 Accounts payable - intercompany 35,005 447,577 127 (482,709 ) — Asset retirement obligation 195 — — — 195 Derivative instruments 67,179 — — — 67,179 Current maturities of long-term debt 452 — — — 452 Total current liabilities 429,006 527,541 127 (482,709 ) 473,965 Long-term derivative instrument 5,259 — — — 5,259 Asset retirement obligation 34,653 6,489 — — 41,142 Long-term debt, net of current maturities 1,631,809 — — — 1,631,809 Total liabilities 2,100,727 534,030 127 (482,709 ) 2,152,175 Stockholders’ equity: Common stock 1,828 — — — 1,828 Paid-in capital 4,408,236 1,872,598 257,700 (2,130,298 ) 4,408,236 Accumulated other comprehensive (loss) income (51,685 ) — (49,613 ) 49,613 (51,685 ) Retained (deficit) earnings (1,556,625 ) 38,010 (161,375 ) 123,365 (1,556,625 ) Total stockholders’ equity 2,801,754 1,910,608 46,712 (1,957,320 ) 2,801,754 Total liabilities and stockholders ’ equity $ 4,902,481 $ 2,444,638 $ 46,839 $ (2,440,029 ) $ 4,953,929 CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) December 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 1,273,882 $ 1,993 $ — $ — $ 1,275,875 Restricted Cash 185,000 — — — $ 185,000 Accounts receivable - oil and gas 137,087 37,496 — (37,822 ) 136,761 Accounts receivable - related parties 16 — — — 16 Accounts receivable - intercompany 449,517 1,151 — (450,668 ) — Prepaid expenses and other current assets 6,230 1,409 — — 7,639 Short-term derivative instruments 3,488 — — — 3,488 Total current assets 2,055,220 42,049 — (488,490 ) 1,608,779 Property and equipment: Oil and natural gas properties, full-cost accounting, 5,655,125 417,524 — (729 ) 6,071,920 Other property and equipment 68,943 43 — — 68,986 Accumulated depletion, depreciation, amortization and impairment (3,789,746 ) (34 ) — — (3,789,780 ) Property and equipment, net 1,934,322 417,533 — (729 ) 2,351,126 Other assets: Equity investments and investments in subsidiaries 236,327 33,590 45,213 (71,210 ) 243,920 Long-term derivative instruments 5,696 — — — 5,696 Deferred tax asset 4,692 — — — 4,692 Other assets 8,932 — — — 8,932 Total other assets 255,647 33,590 45,213 (71,210 ) 263,240 Total assets $ 4,245,189 $ 493,172 $ 45,213 $ (560,429 ) $ 4,223,145 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 255,966 $ 9,158 $ — $ — $ 265,124 Accounts payable - intercompany 31,202 457,163 126 (488,491 ) — Asset retirement obligation 195 — — — 195 Derivative instruments 119,219 — — — 119,219 Current maturities of long-term debt 276 — — — 276 Total current liabilities 406,858 466,321 126 (488,491 ) 384,814 Long-term derivative instrument 26,759 — — — 26,759 Asset retirement obligation 34,081 — — — 34,081 Long-term debt, net of current maturities 1,593,599 — — — 1,593,599 Total liabilities 2,061,297 466,321 126 (488,491 ) 2,039,253 Stockholders’ equity: Common stock 1,588 — — — 1,588 Paid-in capital 3,946,442 33,822 257,026 (290,848 ) 3,946,442 Accumulated other comprehensive (loss) income (53,058 ) — (50,931 ) 50,931 (53,058 ) Retained (deficit) earnings (1,711,080 ) (6,971 ) (161,008 ) 167,979 (1,711,080 ) Total stockholders’ equity 2,183,892 26,851 45,087 (71,938 ) 2,183,892 Total liabilities and stockholders ’ equity $ 4,245,189 $ 493,172 $ 45,213 $ (560,429 ) $ 4,223,145
Condensed Consolidating Statements of Operations	CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 272,441 $ 60,563 $ — $ — $ 333,004 Costs and expenses: Lease operating expenses 17,449 1,854 — — 19,303 Production taxes 3,102 804 — — 3,906 Midstream gathering and processing 37,724 10,217 — — 47,941 Depreciation, depletion, and amortization 65,990 1 — — 65,991 General and administrative 12,874 (275 ) 1 — 12,600 Accretion expense 282 — — — 282 Acquisition expense — 1,298 — — 1,298 137,421 13,899 1 — 151,321 INCOME (LOSS) FROM OPERATIONS 135,020 46,664 (1 ) — 181,683 OTHER (INCOME) EXPENSE: Interest expense 25,048 (1,569 ) — — 23,479 Interest income (842 ) — — — (842 ) (Income) loss from equity method investments and investments in subsidiaries (42,614 ) 2,541 365 44,615 4,907 Other (income) expense (1,027 ) (189 ) — 900 (316 ) (19,435 ) 783 365 45,515 27,228 INCOME (LOSS) BEFORE INCOME TAXES 154,455 45,881 (366 ) (45,515 ) 154,455 INCOME TAX EXPENSE — — — — — NET INCOME (LOSS) $ 154,455 $ 45,881 $ (366 ) $ (45,515 ) $ 154,455 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended March 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 156,751 $ 210 $ — $ — $ 156,961 Costs and expenses: Lease operating expenses 16,472 185 — — 16,657 Production taxes 3,087 24 — — 3,111 Midstream gathering and processing 37,623 29 — — 37,652 Depreciation, depletion, and amortization 65,476 1 — — 65,477 Impairment of oil and gas properties 218,991 — — — 218,991 General and administrative 10,612 6 2 — 10,620 Accretion expense 247 — — — 247 352,508 245 2 — 352,755 LOSS FROM OPERATIONS (195,757 ) (35 ) (2 ) — (195,794 ) OTHER (INCOME) EXPENSE: Interest expense 16,022 1 — — 16,023 Interest income (94 ) — — — (94 ) Loss (income) from equity method investments and investments in subsidiaries 30,773 — 23,685 (23,721 ) 30,737 Other income — (2 ) — — (2 ) 46,701 (1 ) 23,685 (23,721 ) 46,664 (LOSS) INCOME BEFORE INCOME TAXES (242,458 ) (34 ) (23,687 ) 23,721 (242,458 ) INCOME TAX BENEFIT (191 ) (191 ) NET (LOSS) INCOME $ (242,267 ) $ (34 ) $ (23,687 ) $ 23,721 $ (242,267 )
Condensed Consolidating Statements of Comprehensive Income (Loss)	CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Amounts in thousands) Three months ended March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 154,455 $ 45,881 $ (366 ) $ (45,515 ) $ 154,455 Foreign currency translation adjustment 1,373 55 1,318 (1,373 ) 1,373 Other comprehensive income (loss) 1,373 55 1,318 (1,373 ) 1,373 Comprehensive income (loss) $ 155,828 $ 45,936 $ 952 $ (46,888 ) $ 155,828 Three months ended March 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net (loss) income $ (242,267 ) $ (34 ) $ (23,687 ) $ 23,721 $ (242,267 ) Foreign currency translation adjustment 9,058 — 10,273 (10,273 ) 9,058 Other comprehensive income (loss) 9,058 — 10,273 (10,273 ) 9,058 Comprehensive (loss) income $ (233,209 ) $ (34 ) $ (13,414 ) $ 13,448 $ (233,209 )
Condensed Consolidating Statements of Cash Flows	CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Amounts in thousands) Three months ended March 31, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 139,260 $ 3,384 $ 1 $ — $ 142,645 Net cash (used in) provided by investing activities (1,372,852 ) (1,348,964 ) (673 ) 1,374,810 (1,347,679 ) Net cash provided by (used in) financing activities 31,644 1,374,137 673 (1,374,810 ) 31,644 Net (decrease) increase in cash and cash equivalents (1,201,948 ) 28,557 1 — (1,173,390 ) Cash and cash equivalents at beginning of period 1,273,882 1,993 — — 1,275,875 Cash and cash equivalents at end of period $ 71,934 $ 30,550 $ 1 $ — $ 102,485 Three months ended March 31, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 83,620 $ 155 $ (1 ) $ — $ 83,774 Net cash (used in) provided by investing activities (157,529 ) (22,500 ) (1,821 ) 24,321 (157,529 ) Net cash provided by (used in) financing activities 415,158 22,500 1,821 (24,321 ) 415,158 Net increase (decrease) in cash and cash equivalents 341,249 155 (1 ) — 341,403 Cash and cash equivalents at beginning of period 112,494 479 1 — 112,974 Cash and cash equivalents at end of period $ 453,743 $ 634 $ — $ — $ 454,377

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) $ / shares in Units, shares in Millions	Feb. 17, 2017USD ($)a$ / sharesshares	Mar. 31, 2017USD ($)	Mar. 31, 2016USD ($)	Dec. 15, 2016$ / shares
Business Acquisition [Line Items]
Acquisition expense		$ 1,298,000	$ 0
Share price (in dollars per share) | $ / shares	$ 19.48			$ 20.96
Vitruvian acquisition
Business Acquisition [Line Items]
Net surface area | a	46,400
Total consideration	$ 1,850,000,000
Payments to acquire businesses	$ 1,354,093,000
Equity interest issued or issuable, number of shares | shares	23.9
Acquisition expense		$ 1,300,000
Goodwill	$ 0
Bargain purchase gain	0
Business acquisition, share price (in dollars per share) | $ / shares				$ 20.96
Decrease in fair value of shares issued for acquisition, amount	$ 35,300,000
Indemnity escrow | Vitruvian acquisition
Business Acquisition [Line Items]
Equity interest issued or issuable, number of shares | shares	5.2

Acquisitions (Allocation of Pur

Acquisitions (Allocation of Purchase Price) (Details) - Vitruvian acquisition $ in Thousands	Feb. 17, 2017USD ($)
Business Acquisition [Line Items]
Cash, net of purchase price adjustments	$ 1,354,093
Fair value of Gulfport’s common stock issued	464,639
Total Consideration	1,818,732
Asset retirement obligations	(6,489)
Total fair value of net identifiable assets acquired	1,818,732
Proved properties
Business Acquisition [Line Items]
Fair value of Gulfport’s common stock issued	362,264
Unproved properties
Business Acquisition [Line Items]
Fair value of Gulfport’s common stock issued	$ 1,462,957

Acquisitions (Pro Forma) (Detai

Acquisitions (Pro Forma) (Details) - Vitruvian acquisition - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Mar. 31, 2016
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenue	$ 26,226
Pro forma revenue		$ 368,903	$ 203,712
Pro forma net income (loss)		$ 175,881	$ (274,207)
Pro forma earnings (loss) per share (basic) (in dollars per share)		$ 1.03	$ (2.03)
Pro forma earnings (loss) per share (diluted) (in dollars per share)		$ 1.03	$ (2.03)

Property and Equipment (Schedul

Property and Equipment (Schedule of Property and Equipment) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Oil and natural gas properties	$ 8,146,321	$ 6,071,920
Office furniture and fixtures	24,649	21,204
Building	45,204	42,530
Land	5,254	5,252
Total property and equipment	8,221,428	6,140,906
Accumulated depletion, depreciation, amortization and impairment	(3,855,629)	(3,789,780)
Property and equipment, net	$ 4,365,799	$ 2,351,126

Property and Equipment (Narrati

Property and Equipment (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Impairment of oil and gas properties	$ 0	$ 218,991
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool	138,300
Capitalized general and administrative costs	8,400	$ 7,100
Capitalized costs of oil and natural gas properties excluded from amortization	$ 3,073,448		$ 1,580,305
Non-producing leases, extension term	5 years
Minimum
Property, Plant and Equipment [Line Items]
Expected number of years amortization will commence	3 years
Maximum
Property, Plant and Equipment [Line Items]
Expected number of years amortization will commence	5 years

Property and Equipment (Summary

Property and Equipment (Summary of Oil and Gas Properties Not Subject to Amortization) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	$ 3,073,448	$ 1,580,305
Utica
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	1,592,683
MidCon
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	1,477,643
Niobrara
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	2,172
Southern Louisiana
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	484
Bakken
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	98
Other
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	$ 368

Property and Equipment (Sched40

Property and Equipment (Schedule of Asset Retirement Obligation) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation, beginning of period	$ 34,276	$ 26,437
Liabilities incurred	6,779	1,914
Liabilities settled	0	(52)
Accretion expense	282	247
Asset retirement obligation as of end of period	41,337	28,546
Less current portion	195	75	$ 195
Asset retirement obligation, long-term	$ 41,142	$ 28,471	$ 34,081

Equity Investments (Investments

Equity Investments (Investments Accounted for by the Equity Method) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Equity investments and investments in subsidiaries	$ 251,370		$ 243,920
(Income) loss from equity method investments	$ 4,907	$ 30,737
Investment in Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	23.50%
Equity investments and investments in subsidiaries	$ 0		0
(Income) loss from equity method investments	$ (243)	(159)
Investment in Tatex Thailand III, LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	17.90%
Equity investments and investments in subsidiaries	$ 0		0
(Income) loss from equity method investments	$ 0	0
Investment in Grizzly Oil Sands ULC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	24.9999%
Equity investments and investments in subsidiaries	$ 46,838		45,213
(Income) loss from equity method investments	$ 365	23,685
Investment in Timber Wolf Terminals LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	50.00%
Equity investments and investments in subsidiaries	$ 987		991
(Income) loss from equity method investments	$ 4	3
Investment in Windsor Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	22.50%
Equity investments and investments in subsidiaries	$ 25,815		25,749
(Income) loss from equity method investments	$ (311)	(167)
Investment in Stingray Cementing LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	50.00%
Equity investments and investments in subsidiaries	$ 1,768		1,920
(Income) loss from equity method investments	$ 128	30
Investment in Blackhawk Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	48.50%
Equity investments and investments in subsidiaries	$ 0		0
(Income) loss from equity method investments	$ 0	0
Investment in Stingray Energy Services LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	50.00%
Equity investments and investments in subsidiaries	$ 3,967		4,215
(Income) loss from equity method investments	$ 197	502
Investment in Sturgeon Acquisitions LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	25.00%
Equity investments and investments in subsidiaries	$ 20,458		20,526
(Income) loss from equity method investments	$ 68	377
Investment in Mammoth Energy Services, Inc.
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	24.20%
Equity investments and investments in subsidiaries	$ 110,875		111,717
(Income) loss from equity method investments	$ 2,158	6,466
Investment in Strike Force Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	25.00%
Equity investments and investments in subsidiaries	$ 40,662		$ 33,589
(Income) loss from equity method investments	$ 2,541	$ 0

Equity Investments (Equity Inve

Equity Investments (Equity Investments Balance Sheet Disclosure) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Current assets	$ 151,587	$ 148,733
Noncurrent assets	1,342,012	1,305,407
Current liabilities	97,329	57,173
Noncurrent liabilities	$ 59,721	$ 67,680

Equity Investments (Equity In43

Equity Investments (Equity Investment Income Statement Disclosure) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Gross revenue	$ 94,478	$ 43,307
Net loss	$ (25,339)	$ (25,308)

Equity Investments (Narrative)

Equity Investments (Narrative) (Details) $ / shares in Units, a in Thousands, $ in Thousands	1 Months Ended	3 Months Ended				12 Months Ended
	Oct. 31, 2016USD ($)$ / sharesshares	Mar. 31, 2017USD ($)a	Mar. 31, 2016USD ($)	Dec. 31, 2014entity	Sep. 30, 2014a	Dec. 31, 2014USD ($)	Feb. 29, 2016	Feb. 01, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
(Income) loss from equity method investments		$ 4,907	$ 30,737
Distributions from equity method investments		631	138
Payments for equity method investments		$ 10,673	1,821
IPO | Common Stock | Mammoth Energy Partners LP
Schedule of Equity Method Investments [Line Items]
Number of shares sold by Mammoth Energy (in shares) | shares	7,750,000
Shares issued, price per share (in dollars per share) | $ / shares	$ 15
Mammoth Energy Partners LP | IPO | Common Stock
Schedule of Equity Method Investments [Line Items]
Equity method investment (in shares) | shares	76,250
Proceeds from sale of equity	$ 1,100
APICO, LLP | Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage		8.50%
Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent		23.50%
(Income) loss from equity method investments		$ (243)	(159)
Tatex Thailand III, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent		17.90%
(Income) loss from equity method investments		$ 0	0
Grizzly Oil Sands ULC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent		24.9999%
Gas and oil area, reserve (acres) | a		830
(Income) loss from equity method investments		$ 365	23,685
Other than temporary impairment loss			23,100
Equity method investment, amount of cash calls, based on proportionate ownership interest		700
Equity method investments, increase (decrease) due to foreign currency translation adjustment		$ 1,300	10,300
Grizzly Oil Sands ULC | Level 3
Schedule of Equity Method Investments [Line Items]
Equity method investments, fair value of minority interest			39,100
Windsor Midstream LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent		22.50%
(Income) loss from equity method investments		$ (311)	(167)
Distributions from equity method investments		$ 200	100
Sturgeon Acquisitions LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent		25.00%
(Income) loss from equity method investments		$ 68	377
Payments for equity method investments						$ 20,700
Mammoth Energy Services LP
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent		24.20%		30.50%		30.50%
Number of entities contributed for ownership interest | entity				4
Equity method investments, increase (decrease) due to foreign currency translation adjustment		$ 100	(1,200)
Shares received from equity method investee in exchange for ownership interest (in shares) | shares	9,150,000
Mammoth Energy Services LP | IPO | Common Stock | Certain selling stockholders
Schedule of Equity Method Investments [Line Items]
Number of shares sold by Mammoth Energy (in shares) | shares	7,500,000
Mammoth Energy Services LP | IPO | Common Stock | Selling stockholders
Schedule of Equity Method Investments [Line Items]
Number of shares sold by Mammoth Energy (in shares) | shares	250,000
Strike Force Midstream LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent		25.00%
(Income) loss from equity method investments		$ 2,541	$ 0
Equity method investment, amount of cash calls, based on proportionate ownership interest		10,000
Distributions from equity method investments		$ 400
Strike Force Midstream LLC | Rice Energy Inc
Schedule of Equity Method Investments [Line Items]
Ownership percentage by parent							75.00%
Strike Force Midstream LLC | Level 3
Schedule of Equity Method Investments [Line Items]
Equity method investments, fair value of minority interest								$ 22,500
Phu Horm Field | APICO, LLP
Schedule of Equity Method Investments [Line Items]
Gas and oil area, reserve (acres) | a		180
Concession Acreage in Southeast Asia | Tatex Thailand III, LLC
Schedule of Equity Method Investments [Line Items]
Gas and oil area, reserve (acres) | a					245

Long-Term Debt (Break-Down of L

Long-Term Debt (Break-Down of Long-Term Debt) (Details) - USD ($) $ in Thousands		Mar. 31, 2017	Dec. 31, 2016	Dec. 21, 2016	Oct. 31, 2016	Oct. 14, 2016	Apr. 21, 2015
Debt Instrument [Line Items]
Deferred finance costs, net		$ (31,486)	$ (27,174)
Less: current maturities of long term debt		(452)	(276)
Long-term debt, net of current maturities		1,631,809	1,593,599
Revolving credit agreement
Debt Instrument [Line Items]
Long-term debt	[1]		0
Construction loans
Debt Instrument [Line Items]
Long-term debt	[2]		$ 21,049
Deferred finance costs, net		$ (100)
7.75% Senior Notes due 2020 | Senior notes
Debt Instrument [Line Items]
Stated interest rate, percent		7.75%	7.75%
Long-term debt	[3]	$ 0	$ 0
6.625% Senior Notes | Senior notes
Debt Instrument [Line Items]
Stated interest rate, percent		6.625%	6.625%				6.625%
Long-term debt	[4]	$ 350,000	$ 350,000
Deferred finance costs, net		$ (5,800)
6.000% Senior Notes due 2024 | Senior notes
Debt Instrument [Line Items]
Stated interest rate, percent		6.00%	6.00%		6.00%	6.00%
Long-term debt	[4]	$ 650,000	$ 650,000
Deferred finance costs, net		$ (10,700)
6.375% Senior Notes due 2025 | Senior notes
Debt Instrument [Line Items]
Stated interest rate, percent		6.375%	6.375%	6.375%
Long-term debt	[4]	$ 600,000	$ 600,000
Deferred finance costs, net		$ (14,900)
[1]	The Company has entered into a senior secured revolving credit facility, as amended, with The Bank of Nova Scotia, as the lead arranger and administrative agent and certain lenders from time to time party thereto. The credit agreement provides for a maximum facility amount of $1.5 billion and matures on June 6, 2018. On December 13, 2016, the Company further amended its revolving credit facility to, among other things, (a) reset the maturity date to December 31, 2021, (b) adjust lenders, (c) increase the basket for unsecured debt issuances to $1.6 billion, (d) increase the interest rates by 50 basis points, (e) increase the mortgage requirement to 85% (from 80%), and (f) add deposit account control agreement language. On March 29, 2017, the Company further amended its revolving credit facility to, among other things, amend the definition of the term EBITDAX to permit pro forma treatment of acquisitions that involve the payment of consideration by Gulfport and its subsidiaries in excess of $50.0 million and of dispositions of property or series of related dispositions of properties that yields gross proceeds to Gulfport or any of its subsidiaries in excess of $50.0 million.As of March 31, 2017, the borrowing base was set at $700.0 million and $40.0 million was outstanding under the revolving credit facility. At March 31, 2017, the total availability for future borrowings under the revolving credit facility, after giving effect to an aggregate of $238.7 million of letters of credit, was $421.3 million. The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. On May 4, 2017, the revolving credit facility was further amended to increase the borrowing base from $700.0 million to $1.0 billion, adjust certain of the Company's investment baskets and add five additional banks to the syndicate.Advances under the revolving credit facility may be in the form of either base rate loans or eurodollar loans. The interest rate for base rate loans is equal to (1) the applicable rate, which ranges from 1.00% to 2.00%, plus (2) the highest of: (a) the federal funds rate plus 0.50%, (b) the rate of interest in effect for such day as publicly announced from time to time by agent as its “prime rate,” and (c) the eurodollar rate for an interest period of one month plus 1.00%. The interest rate for eurodollar loans is equal to (1) the applicable rate, which ranges from 2.00% to 3.00%, plus (2) the London interbank offered rate that appears on pages LIBOR01 or LIBOR02 of the Reuters screen that displays such rate for deposits in U.S. dollars, or, if such rate is not available, the rate as administered by ICE Benchmark Administration (or any other person that takes over administration of such rate) per annum equal to the offered rate on such other page or service that displays on average London interbank offered rate as determined by ICE Benchmark Administration (or any other person that takes over administration of such rate) for deposits in U.S. dollars, or, if such rate is not available, the average quotations for three major New York money center banks of whom the agent shall inquire as the “London Interbank Offered Rate” for deposits in U.S. dollars. At March 31, 2107, amounts borrowed under the credit facility bore interest at the eurodollar rate (3.18%).The revolving credit facility contains customary negative covenants including, but not limited to, restrictions on the Company’s and its subsidiaries’ ability to: •incur indebtedness; •grant liens; •pay dividends and make other restricted payments; •make investments; •make fundamental changes; •enter into swap contracts and forward sales contracts; •dispose of assets; •change the nature of their business; and •enter into transactions with affiliates. The negative covenants are subject to certain exceptions as specified in the revolving credit facility. The revolving credit facility also contains certain affirmative covenants, including, but not limited to the following financial covenants: (i) the ratio of net funded debt to EBITDAX (net income, excluding (i) any non-cash revenue or expense associated with swap contracts resulting from ASC 815 and (ii) any cash or non-cash revenue or expense attributable to minority investments plus without duplication and, in the case of expenses, to the extent deducted from revenues in determining net income, the sum of (a) the aggregate amount of consolidated interest expense for such period, (b) the aggregate amount of income, franchise, capital or similar tax expense (other than ad valorem taxes) for such period, (c) all amounts attributable to depletion, depreciation, amortization and asset or goodwill impairment or writedown for such period, (d) all other non-cash charges, (e) exploration costs deducted in determining net income under successful efforts accounting, (f) actual cash distributions received from minority investments, (g) to the extent actually reimbursed by insurance, expenses with respect to liability on casualty events or business interruption, and (h) all reasonable transaction expenses related to dispositions and acquisitions of assets, investments and debt and equity offerings (provided that expenses related to any unsuccessful disposition will be limited to $3.0 million in the aggregate) for a twelve-month period may not be greater than 4.00 to 1.00; and (ii) the ratio of EBITDAX to interest expense for a twelve-month period may not be less than 3.00 to 1.00. The Company was in compliance with all covenants at March 31, 2017.
[2]	On June 4, 2015, the Company entered into a construction loan agreement (the “Construction Loan”) with InterBank for the construction of a new corporate headquarters in Oklahoma City, which was substantially completed in December 2016. The Construction Loan allows for maximum principal borrowings of $24.5 million and required the Company to fund 30% of the cost of the construction before any funds could be drawn, which occurred in January 2016. Interest accrues daily on the outstanding principal balance at a fixed rate of 4.50% per annum and is payable on the last day of the month through May 31, 2017. Monthly interest and principal payments are due beginning June 30, 2017, with the final payment due June 4, 2025. At March 31, 2017, the total borrowings under the Construction Loan were approximately $23.7 million.
[3]	(3) On April 21, 2015, the Company issued $350.0 million in aggregate principal amount of 6.625% Senior Notes due 2023 (the “2023 Notes”) to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2023 Notes Offering”). The Company received net proceeds of approximately $343.6 million after initial purchaser discounts and commissions and estimated offering expenses.The 2023 Notes were issued under an indenture, dated as of April 21, 2015, among the Company, the subsidiary guarantors party thereto and Wells Fargo Bank, National Association, as trustee. In October 2015, the 2023 Notes were exchanged for a new issue of substantially identical debt securities registered under the Securities Act. Pursuant to the indenture relating to the 2023 Notes, interest on the 2023 Notes will accrue at a rate of 6.625% per annum on the outstanding principal amount thereof from April 21, 2015, payable semi-annually on May 1 and November 1 of each year, commencing on November 1, 2015. The 2023 Notes are not guaranteed by Grizzly Holdings, Inc. and will not be guaranteed by any of the Company’s future unrestricted subsidiaries.
[4]	On October 14, 2016, the Company issued the 2024 Notes in aggregate principal amount of $650.0 million. The 2024 Notes were issued under an indenture, dated as of October 14, 2016, among the Company, the subsidiary guarantors party thereto and the senior note indenture trustee (the “2024 Indenture”), to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2024 Notes Offering”). Under the 2024 Indenture, interest on the 2024 Notes accrues at a rate of 6.000% per annum on the outstanding principal amount thereof from October 14, 2016, payable semi-annually on April 15 and October 15 of each year, commencing on April 15, 2017. The 2024 Notes will mature on October 15, 2024. The Company received approximately $638.9 million in net proceeds from the offering of the 2024 Notes, which was used, together with cash on hand, to purchase the outstanding 2020 Notes in a concurrent cash tender offer, to pay fees and expenses thereof, and to redeem any of the 2020 Notes that remained outstanding after the completion of the tender offer.

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details)

Dec. 21, 2016USD ($)

Dec. 13, 2016USD ($)

Dec. 12, 2016

Oct. 14, 2016USD ($)

Oct. 06, 2016

Dec. 27, 2013

Jan. 31, 2016

Mar. 31, 2017USD ($)

Mar. 31, 2016USD ($)

May 04, 2017USD ($)

Mar. 29, 2017USD ($)

Dec. 31, 2016USD ($)

Oct. 31, 2016USD ($)

Jun. 04, 2015USD ($)

Apr. 21, 2015USD ($)

Aug. 18, 2014USD ($)

Dec. 21, 2012USD ($)

Oct. 17, 2012USD ($)

Debt Instrument [Line Items]

Interest cost capitalized, undeveloped properties

$ 3,100,000

$ 1,600,000

Interest capitalized

3,122,000

1,862,000

Deferred finance costs, net

31,486,000

$ 27,174,000

Building loan

Debt Instrument [Line Items]

Interest capitalized

$ 300,000

Revolving credit agreement

Debt Instrument [Line Items]

Long-term debt

[1]

0

Construction loans

Debt Instrument [Line Items]

Long-term debt

[2]

21,049,000

Deferred finance costs, net

$ 100,000

Amended and restated credit agreement | Maximum

Debt Instrument [Line Items]

Debt covenant ratio for future EBITDAX

4

Amended and restated credit agreement | Revolving credit agreement

Debt Instrument [Line Items]

Borrowing capacity

$ 700,000,000

Long-term debt

[1]

40,000,000

Remaining borrowing capacity

[1]

$ 421,300,000

Debt covenant ratio for EBITDAX

3

6.625% Senior Notes due 2023 | Senior notes

Debt Instrument [Line Items]

Stated interest rate, percent

6.625%

Debt instrument, amount

$ 350,000,000

6.625% Senior Notes | Senior notes

Debt Instrument [Line Items]

Long-term debt

[3]

$ 350,000,000

$ 350,000,000

Stated interest rate, percent

6.625%

6.625%

6.625%

Building loan outstanding amount of building loan refinanced

$ 343,600,000

Deferred finance costs, net

$ 5,800,000

7.75% Senior Notes due 2020 | Senior notes

Debt Instrument [Line Items]

Long-term debt

[4]

$ 0

$ 0

Stated interest rate, percent

7.75%

7.75%

Debt instrument, amount

$ 600,000,000

Amount validly tendered

$ 600,000,000

Note repurchase offer, conversion ratio

1.042

6.000% Senior Notes due 2024 | Senior notes

Debt Instrument [Line Items]

Long-term debt

[3]

$ 650,000,000

$ 650,000,000

Stated interest rate, percent

6.00%

6.00%

6.00%

6.00%

Debt instrument, amount

$ 650,000,000

Proceeds from issuance of Senior Notes

$ 638,900,000

Deferred finance costs, net

$ 10,700,000

6.375% Senior Notes due 2025 | Senior notes

Debt Instrument [Line Items]

Long-term debt

[3]

$ 600,000,000

$ 600,000,000

Stated interest rate, percent

6.375%

6.375%

6.375%

Debt instrument, amount

$ 600,000,000

Proceeds from issuance of Senior Notes

$ 584,700,000

Deferred finance costs, net

$ 14,900,000

Nova Scotia, Amegy, KeyBank | Amended and restated credit agreement | Revolving credit agreement

Debt Instrument [Line Items]

Revolving credit facility

$ 1,500,000,000

Required minimum down payment, percent

85.00%

80.00%

Minimum acquisition payment limit

$ 50,000,000

Minimum disposition of property limit

$ 50,000,000

Nova Scotia, Amegy, KeyBank | Revolving credit agreement

Debt Instrument [Line Items]

Debt instrument, description of variable rate basis

LIBOR01

Weighted average interest rate

3.18%

Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Base rate | Minimum

Debt Instrument [Line Items]

Stated interest rate, percent

1.00%

Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Base rate | Maximum

Debt Instrument [Line Items]

Stated interest rate, percent

2.00%

Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Federal funds rate

Debt Instrument [Line Items]

Basis spread, percent

0.50%

Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Eurodollar

Debt Instrument [Line Items]

Basis spread, percent

1.00%

Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Eurodollar | Minimum

Debt Instrument [Line Items]

Stated interest rate, percent

2.00%

Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Eurodollar | Maximum

Debt Instrument [Line Items]

Stated interest rate, percent

3.00%

Nova Scotia, Amegy, KeyBank | Unsecured debt | Amended and restated credit agreement | Revolving credit agreement

Debt Instrument [Line Items]

Revolving credit facility

$ 1,600,000,000

Basis spread on variable rate, increase (decrease) during period

0.005

Nova Scotia, Amegy, KeyBank | Letter of credit | Amended and restated credit agreement

Debt Instrument [Line Items]

Credit facility outstanding

$ 238,700,000

Disposition costs, maximum expenses allowed

3,000,000

Wells Fargo Bank | October Notes | Senior notes

Debt Instrument [Line Items]

Stated interest rate, percent

7.75%

Debt instrument, amount

$ 250,000,000

Wells Fargo Bank | December Notes | Senior notes

Debt Instrument [Line Items]

Stated interest rate, percent

7.75%

Debt instrument, amount

$ 50,000,000

Wells Fargo Bank | August Notes | Senior notes

Debt Instrument [Line Items]

Stated interest rate, percent

7.75%

Debt instrument, amount

$ 300,000,000

InterBank | Revolving credit agreement | Construction loans

Debt Instrument [Line Items]

Revolving credit facility

$ 24,500,000

Stated interest rate, percent

4.50%

InterBank | Letter of credit | Construction loans

Debt Instrument [Line Items]

Required minimum down payment, percent

30.00%

Long-term debt

$ 23,747,000

Subsequent event | Five additional lenders | Amended and restated credit agreement | Revolving credit agreement

Debt Instrument [Line Items]

Borrowing capacity

$ 1,000,000,000

[1]

The Company has entered into a senior secured revolving credit facility, as amended, with The Bank of Nova Scotia, as the lead arranger and administrative agent and certain lenders from time to time party thereto. The credit agreement provides for a maximum facility amount of $1.5 billion and matures on June 6, 2018. On December 13, 2016, the Company further amended its revolving credit facility to, among other things, (a) reset the maturity date to December 31, 2021, (b) adjust lenders, (c) increase the basket for unsecured debt issuances to $1.6 billion, (d) increase the interest rates by 50 basis points, (e) increase the mortgage requirement to 85% (from 80%), and (f) add deposit account control agreement language. On March 29, 2017, the Company further amended its revolving credit facility to, among other things, amend the definition of the term EBITDAX to permit pro forma treatment of acquisitions that involve the payment of consideration by Gulfport and its subsidiaries in excess of $50.0 million and of dispositions of property or series of related dispositions of properties that yields gross proceeds to Gulfport or any of its subsidiaries in excess of $50.0 million.As of March 31, 2017, the borrowing base was set at $700.0 million and $40.0 million was outstanding under the revolving credit facility. At March 31, 2017, the total availability for future borrowings under the revolving credit facility, after giving effect to an aggregate of $238.7 million of letters of credit, was $421.3 million. The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. On May 4, 2017, the revolving credit facility was further amended to increase the borrowing base from $700.0 million to $1.0 billion, adjust certain of the Company's investment baskets and add five additional banks to the syndicate.Advances under the revolving credit facility may be in the form of either base rate loans or eurodollar loans. The interest rate for base rate loans is equal to (1) the applicable rate, which ranges from 1.00% to 2.00%, plus (2) the highest of: (a) the federal funds rate plus 0.50%, (b) the rate of interest in effect for such day as publicly announced from time to time by agent as its “prime rate,” and (c) the eurodollar rate for an interest period of one month plus 1.00%. The interest rate for eurodollar loans is equal to (1) the applicable rate, which ranges from 2.00% to 3.00%, plus (2) the London interbank offered rate that appears on pages LIBOR01 or LIBOR02 of the Reuters screen that displays such rate for deposits in U.S. dollars, or, if such rate is not available, the rate as administered by ICE Benchmark Administration (or any other person that takes over administration of such rate) per annum equal to the offered rate on such other page or service that displays on average London interbank offered rate as determined by ICE Benchmark Administration (or any other person that takes over administration of such rate) for deposits in U.S. dollars, or, if such rate is not available, the average quotations for three major New York money center banks of whom the agent shall inquire as the “London Interbank Offered Rate” for deposits in U.S. dollars. At March 31, 2107, amounts borrowed under the credit facility bore interest at the eurodollar rate (3.18%).The revolving credit facility contains customary negative covenants including, but not limited to, restrictions on the Company’s and its subsidiaries’ ability to: •incur indebtedness; •grant liens; •pay dividends and make other restricted payments; •make investments; •make fundamental changes; •enter into swap contracts and forward sales contracts; •dispose of assets; •change the nature of their business; and •enter into transactions with affiliates. The negative covenants are subject to certain exceptions as specified in the revolving credit facility. The revolving credit facility also contains certain affirmative covenants, including, but not limited to the following financial covenants: (i) the ratio of net funded debt to EBITDAX (net income, excluding (i) any non-cash revenue or expense associated with swap contracts resulting from ASC 815 and (ii) any cash or non-cash revenue or expense attributable to minority investments plus without duplication and, in the case of expenses, to the extent deducted from revenues in determining net income, the sum of (a) the aggregate amount of consolidated interest expense for such period, (b) the aggregate amount of income, franchise, capital or similar tax expense (other than ad valorem taxes) for such period, (c) all amounts attributable to depletion, depreciation, amortization and asset or goodwill impairment or writedown for such period, (d) all other non-cash charges, (e) exploration costs deducted in determining net income under successful efforts accounting, (f) actual cash distributions received from minority investments, (g) to the extent actually reimbursed by insurance, expenses with respect to liability on casualty events or business interruption, and (h) all reasonable transaction expenses related to dispositions and acquisitions of assets, investments and debt and equity offerings (provided that expenses related to any unsuccessful disposition will be limited to $3.0 million in the aggregate) for a twelve-month period may not be greater than 4.00 to 1.00; and (ii) the ratio of EBITDAX to interest expense for a twelve-month period may not be less than 3.00 to 1.00. The Company was in compliance with all covenants at March 31, 2017.

[2]

On June 4, 2015, the Company entered into a construction loan agreement (the “Construction Loan”) with InterBank for the construction of a new corporate headquarters in Oklahoma City, which was substantially completed in December 2016. The Construction Loan allows for maximum principal borrowings of $24.5 million and required the Company to fund 30% of the cost of the construction before any funds could be drawn, which occurred in January 2016. Interest accrues daily on the outstanding principal balance at a fixed rate of 4.50% per annum and is payable on the last day of the month through May 31, 2017. Monthly interest and principal payments are due beginning June 30, 2017, with the final payment due June 4, 2025. At March 31, 2017, the total borrowings under the Construction Loan were approximately $23.7 million.

[3]

On October 14, 2016, the Company issued the 2024 Notes in aggregate principal amount of $650.0 million. The 2024 Notes were issued under an indenture, dated as of October 14, 2016, among the Company, the subsidiary guarantors party thereto and the senior note indenture trustee (the “2024 Indenture”), to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2024 Notes Offering”). Under the 2024 Indenture, interest on the 2024 Notes accrues at a rate of 6.000% per annum on the outstanding principal amount thereof from October 14, 2016, payable semi-annually on April 15 and October 15 of each year, commencing on April 15, 2017. The 2024 Notes will mature on October 15, 2024. The Company received approximately $638.9 million in net proceeds from the offering of the 2024 Notes, which was used, together with cash on hand, to purchase the outstanding 2020 Notes in a concurrent cash tender offer, to pay fees and expenses thereof, and to redeem any of the 2020 Notes that remained outstanding after the completion of the tender offer.

[4]

(3) On April 21, 2015, the Company issued $350.0 million in aggregate principal amount of 6.625% Senior Notes due 2023 (the “2023 Notes”) to qualified institutional buyers pursuant to Rule 144A under the Securities Act and to certain non-U.S. persons in accordance with Regulation S under the Securities Act (the “2023 Notes Offering”). The Company received net proceeds of approximately $343.6 million after initial purchaser discounts and commissions and estimated offering expenses.The 2023 Notes were issued under an indenture, dated as of April 21, 2015, among the Company, the subsidiary guarantors party thereto and Wells Fargo Bank, National Association, as trustee. In October 2015, the 2023 Notes were exchanged for a new issue of substantially identical debt securities registered under the Securities Act. Pursuant to the indenture relating to the 2023 Notes, interest on the 2023 Notes will accrue at a rate of 6.625% per annum on the outstanding principal amount thereof from April 21, 2015, payable semi-annually on May 1 and November 1 of each year, commencing on November 1, 2015. The 2023 Notes are not guaranteed by Grizzly Holdings, Inc. and will not be guaranteed by any of the Company’s future unrestricted subsidiaries.

Common Stock and Changes in C47

Common Stock and Changes in Capitalization (Narrative) (Details) - USD ($) $ in Thousands	Feb. 17, 2017	Mar. 15, 2016	Mar. 31, 2017	Mar. 31, 2016
Class of Stock [Line Items]
Proceeds from issuance of common stock, net of offering costs		$ 411,900	$ (5,321)	$ 411,918
Vitruvian acquisition
Class of Stock [Line Items]
Total consideration	$ 1,850,000
Payments to acquire businesses	$ 1,354,093
Equity interest issued or issuable, number of shares	23,900,000
Indemnity escrow | Vitruvian acquisition
Class of Stock [Line Items]
Equity interest issued or issuable, number of shares	5,200,000
Common Stock
Class of Stock [Line Items]
Issuance of Common Stock in public offerings, net of related expenses (in shares)		16,905,000		16,905,000
Over-allotment option | Common Stock
Class of Stock [Line Items]
Issuance of Common Stock in public offerings, net of related expenses (in shares)		2,205,000

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Share-based Compensation [Abstract]
Stock-based compensation expense	$ 2.6	$ 3.3
Capitalized stock-based compensation	1	$ 1.3
Unrecognized compensation expense	$ 18.1
Weighted average period of expense recognition period	1 year 7 months 28 days

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary of Restricted Stock Award and Unit Activity) (Details) - Restricted Stock	3 Months Ended
	Mar. 31, 2017$ / sharesshares
Number of Unvested Restricted Shares
Unvested shares as of January 1, 2016 (in shares) | shares	613,056
Granted (in shares) | shares	477,768
Vested (in shares) | shares	(153,868)
Forfeited (in shares) | shares	(65,438)
Unvested shares as of March 31, 2017 (in shares) | shares	871,518
Weighted Average Grant Date Fair Value
Unvested shares as of January 1, 2016 (in dollars per share) | $ / shares	$ 32.90
Granted (in dollars per share) | $ / shares	17.74
Vested (in dollars per share) | $ / shares	31.98
Forfeited (in dollars per share) | $ / shares	31.23
Unvested shares as of March 31, 2017 (in dollars per share) | $ / shares	$ 24.88

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Earnings Per Share Reconciliation) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Basic:
Net loss (loss)	$ 154,455	$ (242,267)
Net income (loss) (in shares)	170,272,685	111,509,585
Net income (loss) (in dollars per share)	$ 0.91	$ (2.17)
Effect of dilutive securities:
Stock options and awards	$ 0	$ 0
Stock options and awards (in shares)	215,834	0
Diluted:
Net income (loss)	$ 154,455	$ (242,267)
Net income (loss) (in share)	170,488,519	111,509,585
Net income (loss) (in dollars per share)	$ 0.91	$ (2.17)
Common stock considered anti-dilutive (in shares)		650,606

Commitments and Contingencies51

Commitments and Contingencies (Narrative) (Details) $ in Thousands	Jul. 29, 2016defendant	Feb. 09, 2016defendant	Mar. 11, 1997	Jul. 29, 2016claim	Dec. 31, 1997USD ($)well	Mar. 31, 2017USD ($)well	Mar. 31, 2016USD ($)
Commitments [Line Items]
Plugging and abandonment escrow account on the WCBB properties (Note 10)						$ 3,100
Number of claims filed | claim				2
Judicial District Court for the Parish of Cameron
Commitments [Line Items]
Number of defendants | defendant		26
Judicial District Court for the Parish of Vermillion
Commitments [Line Items]
Number of defendants | defendant	40
WCBB
Commitments [Line Items]
Purchasing remaining percent interest In oil and gas property, percent					50.00%
Payments held for restricted cash					$ 18
Significant plugging commitment minimum number of wells to be plugged | well					20
Tenure of minimum wells to be plugged			20 years
Number of wells plugged | well						513
Loss on long-term purchase commitment | Muskie Proppant LLC
Commitments [Line Items]
Long-term purchase commitment, accrued damages , amount						$ 0	$ 1,300

Commitments and Contingencies52

Commitments and Contingencies (Operating Leases Future Minimum Lease Commitments) (Details) $ in Thousands	Mar. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining 2,017	$ 129
2,018	54
Total	$ 183

Commitments and Contingencies53

Commitments and Contingencies (Firm Transportation Commitments) (Details) $ in Thousands	Mar. 31, 2017USD ($)MMBTU / d
Other Commitments [Line Items]
Firm sale contracts (in MMBtu's) | MMBTU / d	2,952,375
Long-term Commitment (Excluding Unconditional Purchase Obligation) [Abstract]
Remaining 2017 | MMBTU / d	725,625
2018 | MMBTU / d	457,000
2019 | MMBTU / d	604,750
2020 | MMBTU / d	518,000
2021 | MMBTU / d	371,000
Thereafter | MMBTU / d	276,000
Total | MMBTU / d	2,952,375
Purchase commitment
Other Commitments [Abstract]
2,018	$ 39,330
Total	78,660
Transportation commitment
Other Commitments [Abstract]
Remaining 2,017	143,816
2,018	241,709
2,019	241,708
2,020	240,746
2,021	239,786
Thereafter	2,705,270
Total	$ 3,813,035

Commitments and Contingencies54

Commitments and Contingencies (Other Commitments) (Details) - Purchase commitment $ in Thousands	Mar. 31, 2017USD ($)
Other Commitments [Line Items]
Remaining 2,017	$ 39,330
2,018	39,330
Total	$ 78,660

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Details)	3 Months Ended
	Mar. 31, 2017MMBTU / d$ / MMBTU
Derivative [Line Items]
Derivative, extension option term	12 months
2,018
Derivative [Line Items]
Daily Volume | MMBTU / d	30,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.36
2018 | Short
Derivative [Line Items]
Daily Volume | MMBTU / d	30,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.36

Derivative Instruments (Schedul

Derivative Instruments (Schedule of Derivative Instruments) (Details)	Mar. 31, 2017bbl / dMMBTU / d$ / bbl$ / MMBTU
Remaining 2017 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume | MMBTU / d	576,845
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.18
Remaining 2017 | ARGUS LLS
Derivative [Line Items]
Daily Volume | bbl / d	1,665
Weighted average price (in usd per MMB/Bblstu) | $ / bbl	52.32
Remaining 2017 | NYMEX WTI
Derivative [Line Items]
Daily Volume | bbl / d	4,113
Weighted average price (in usd per MMB/Bblstu) | $ / bbl	54.97
Remaining 2017 | Mont Belvieu C3
Derivative [Line Items]
Daily Volume | bbl / d	3,000
Weighted average price (in usd per MMB/Bblstu) | $ / bbl	26.63
Remaining 2017 | Mont Belvieu C5
Derivative [Line Items]
Daily Volume | bbl / d	250
Weighted average price (in usd per MMB/Bblstu) | $ / bbl	49.14
2,018
Derivative [Line Items]
Daily Volume | MMBTU / d	30,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.36
2018 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume | MMBTU / d	543,767
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.09
2018 | NYMEX WTI
Derivative [Line Items]
Daily Volume | bbl / d	899
Weighted average price (in usd per MMB/Bblstu) | $ / bbl	55.31
2019 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume | MMBTU / d	9,863
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.27
Short | 2018
Derivative [Line Items]
Daily Volume | MMBTU / d	30,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.36
Short | Call Option | Remaining 2017 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume | MMBTU / d	65,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.11
Short | Call Option | Remaining 2017 | NYMEX Henry Hub to NPG Mid-Continent
Derivative [Line Items]
Daily Volume | MMBTU / d	50,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	0.26
Short | Call Option | 2018 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume | MMBTU / d	80,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.29
Short | Call Option | 2018 | NYMEX Henry Hub to NPG Mid-Continent
Derivative [Line Items]
Daily Volume | MMBTU / d	12,329
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	0.26
Short | Call Option | 2019 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume | MMBTU / d	4,932
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.16

Derivative Instruments (Sched57

Derivative Instruments (Schedule of Derivative Instruments in Statement of Financial Position) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Short-term derivative instruments - asset	$ 18,925	$ 3,488
Long-term derivative instruments - asset	23,515	5,696
Short-term derivative instruments - liability	67,179	119,219
Long-term derivative instruments - liability	$ 5,259	$ 26,759

Derivative Instruments (Net Gai

Derivative Instruments (Net Gain (Loss) on Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Derivative [Line Items]
Net gain on gas, oil, and NGL derivatives	$ 99,577	$ 57,735
Natural gas derivatives
Derivative [Line Items]
Net gain on gas, oil, and NGL derivatives	86,277	57,000
Oil derivatives
Derivative [Line Items]
Net gain on gas, oil, and NGL derivatives	10,905	1,282
Natural gas liquids derivatives
Derivative [Line Items]
Net gain on gas, oil, and NGL derivatives	$ 2,395	$ (547)

Derivative Instruments (Sched59

Derivative Instruments (Schedule of Offsetting) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross Assets Presented in the Consolidated Balance Sheet	$ 42,440	$ 9,184
Gross Assets Subject to Mater Netting Agreement - assets	(41,180)	(9,184)
Net Amount - assets	1,260	0
Gross Liabilities Presented in the Consolidated Balance Sheet	(72,438)	(145,978)
Gross Amounts Subject to Master Netting Agreement - liabilities	41,180	9,184
Net Amount - liabilities	$ (31,258)	$ (136,794)

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Feb. 01, 2016
Liabilities:
Asset retirement obligation capitalized	$ 6,779	$ 1,914
Level 1
Assets:
Derivative Instruments	0		$ 0
Liabilities:
Derivative Instruments	0		0
Level 2
Assets:
Derivative Instruments	42,440		9,184
Liabilities:
Derivative Instruments	72,438		145,978
Level 3
Assets:
Derivative Instruments	0		0
Liabilities:
Derivative Instruments	0		$ 0
Asset retirement obligation capitalized	$ 6,800
Level 3 | Investment in Grizzly Oil Sands ULC
Liabilities:
Equity investment		$ 39,100
Level 3 | Investment in Strike Force Midstream LLC
Liabilities:
Equity investment				$ 22,500

Fair Value of Financial Instr61

Fair Value of Financial Instruments (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Deferred finance costs, net	$ 31,486	$ 27,174
Senior notes | 6.625% Senior Notes
Debt Instrument [Line Items]
Deferred finance costs, net	5,800
Senior notes | 6.000% Senior Notes due 2024
Debt Instrument [Line Items]
Deferred finance costs, net	10,700
Senior notes | 6.375% Senior Notes due 2025
Debt Instrument [Line Items]
Deferred finance costs, net	14,900
Carry value | Senior notes
Debt Instrument [Line Items]
Fair value of notes	1,600,000
Fair value | Senior notes
Debt Instrument [Line Items]
Fair value of notes	$ 1,600,000

Condensed Consolidating Finan62

Condensed Consolidating Financial Information (Narrative) (Details) - Senior notes - USD ($)	Dec. 21, 2016	Oct. 31, 2016	Oct. 14, 2016	Apr. 21, 2015	Aug. 18, 2014
7.75% Senior Notes due 2020
Condensed Financial Statements, Captions [Line Items]
Debt instrument, amount					$ 600,000,000
Amount validly tendered		$ 600,000,000
6.625% Senior Notes due 2023
Condensed Financial Statements, Captions [Line Items]
Debt instrument, amount				$ 350,000,000
6.000% Senior Notes due 2024
Condensed Financial Statements, Captions [Line Items]
Debt instrument, amount			$ 650,000,000
6.375% Senior Notes due 2025
Condensed Financial Statements, Captions [Line Items]
Debt instrument, amount	$ 600,000,000

Condensed Consolidating Finan63

Condensed Consolidating Financial Information (Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 102,485	$ 1,275,875	$ 454,377	$ 112,974
Restricted Cash	0	185,000
Accounts receivable—oil and gas	158,154	136,761
Accounts receivable - related parties	39	16
Accounts receivable - intercompany		0
Prepaid expenses and other current assets	16,005	7,639
Short-term derivative instruments	18,925	3,488
Total current assets	295,608	1,608,779
Property and equipment:
Oil and natural gas properties	8,146,321	6,071,920
Other property and equipment	75,107	68,986
Accumulated depletion, depreciation, amortization and impairment	(3,855,629)	(3,789,780)
Property and equipment, net	4,365,799	2,351,126
Other assets:
Equity investments and investments in subsidiaries	251,370	243,920
Long-term derivative instruments	23,515	5,696
Deferred tax asset	4,692	4,692
Other assets	12,945	8,932
Total other assets	292,522	263,240
Total assets	4,953,929	4,223,145
Current liabilities:
Accounts payable and accrued liabilities	406,139	265,124
Accounts payable - intercompany	0	0
Asset retirement obligation—current	195	195	75
Derivative instruments	67,179	119,219
Current maturities of long-term debt	452	276
Total current liabilities	473,965	384,814
Long-term derivative instrument	5,259	26,759
Asset retirement obligation—long-term	41,142	34,081	28,471
Long-term debt, net of current maturities	1,631,809	1,593,599
Total liabilities	2,152,175	2,039,253
Stockholders’ equity:
Common stock	1,828	1,588
Paid-in capital	4,408,236	3,946,442
Accumulated other comprehensive (loss) income	(51,685)	(53,058)
Retained (deficit) earnings	(1,556,625)	(1,711,080)
Total stockholders’ equity	2,801,754	2,183,892	2,220,789	2,038,837
Total liabilities and stockholders’ equity	4,953,929	4,223,145
Reportable Legal Entities | Parent
Current assets:
Cash and cash equivalents	71,934	1,273,882	453,743	112,494
Restricted Cash		185,000
Accounts receivable—oil and gas	106,008	137,087
Accounts receivable - related parties	39	16
Accounts receivable - intercompany	447,275	449,517
Prepaid expenses and other current assets	12,330	6,230
Short-term derivative instruments	18,925	3,488
Total current assets	656,511	2,055,220
Property and equipment:
Oil and natural gas properties	5,869,066	5,655,125
Other property and equipment	75,064	68,943
Accumulated depletion, depreciation, amortization and impairment	(3,855,594)	(3,789,746)
Property and equipment, net	2,088,536	1,934,322
Other assets:
Equity investments and investments in subsidiaries	2,120,462	236,327
Long-term derivative instruments	23,515	5,696
Deferred tax asset	4,692	4,692
Other assets	8,765	8,932
Total other assets	2,157,434	255,647
Total assets	4,902,481	4,245,189
Current liabilities:
Accounts payable and accrued liabilities	326,175	255,966
Accounts payable - intercompany	35,005	31,202
Asset retirement obligation—current	195	195
Derivative instruments	67,179	119,219
Current maturities of long-term debt	452	276
Total current liabilities	429,006	406,858
Long-term derivative instrument	5,259	26,759
Asset retirement obligation—long-term	34,653	34,081
Long-term debt, net of current maturities	1,631,809	1,593,599
Total liabilities	2,100,727	2,061,297
Stockholders’ equity:
Common stock	1,828	1,588
Paid-in capital	4,408,236	3,946,442
Accumulated other comprehensive (loss) income	(51,685)	(53,058)
Retained (deficit) earnings	(1,556,625)	(1,711,080)
Total stockholders’ equity	2,801,754	2,183,892
Total liabilities and stockholders’ equity	4,902,481	4,245,189
Reportable Legal Entities | Guarantors
Current assets:
Cash and cash equivalents	30,550	1,993	634	479
Restricted Cash		0
Accounts receivable—oil and gas	52,146	37,496
Accounts receivable - related parties	0	0
Accounts receivable - intercompany	35,434	1,151
Prepaid expenses and other current assets	3,675	1,409
Short-term derivative instruments	0	0
Total current assets	121,805	42,049
Property and equipment:
Oil and natural gas properties	2,277,984	417,524
Other property and equipment	43	43
Accumulated depletion, depreciation, amortization and impairment	(35)	(34)
Property and equipment, net	2,277,992	417,533
Other assets:
Equity investments and investments in subsidiaries	40,661	33,590
Long-term derivative instruments	0	0
Deferred tax asset	0	0
Other assets	4,180	0
Total other assets	44,841	33,590
Total assets	2,444,638	493,172
Current liabilities:
Accounts payable and accrued liabilities	79,964	9,158
Accounts payable - intercompany	447,577	457,163
Asset retirement obligation—current	0	0
Derivative instruments	0	0
Current maturities of long-term debt	0	0
Total current liabilities	527,541	466,321
Long-term derivative instrument	0	0
Asset retirement obligation—long-term	6,489	0
Long-term debt, net of current maturities	0	0
Total liabilities	534,030	466,321
Stockholders’ equity:
Common stock	0	0
Paid-in capital	1,872,598	33,822
Accumulated other comprehensive (loss) income	0	0
Retained (deficit) earnings	38,010	(6,971)
Total stockholders’ equity	1,910,608	26,851
Total liabilities and stockholders’ equity	2,444,638	493,172
Reportable Legal Entities | Non-Guarantor
Current assets:
Cash and cash equivalents	1	0	0	1
Restricted Cash		0
Accounts receivable—oil and gas	0	0
Accounts receivable - related parties	0	0
Accounts receivable - intercompany	0	0
Prepaid expenses and other current assets	0	0
Short-term derivative instruments	0	0
Total current assets	1	0
Property and equipment:
Oil and natural gas properties	0	0
Other property and equipment	0	0
Accumulated depletion, depreciation, amortization and impairment	0	0
Property and equipment, net	0	0
Other assets:
Equity investments and investments in subsidiaries	46,838	45,213
Long-term derivative instruments	0	0
Deferred tax asset	0	0
Other assets	0	0
Total other assets	46,838	45,213
Total assets	46,839	45,213
Current liabilities:
Accounts payable and accrued liabilities	0	0
Accounts payable - intercompany	127	126
Asset retirement obligation—current	0	0
Derivative instruments	0	0
Current maturities of long-term debt	0	0
Total current liabilities	127	126
Long-term derivative instrument	0	0
Asset retirement obligation—long-term	0	0
Long-term debt, net of current maturities	0	0
Total liabilities	127	126
Stockholders’ equity:
Common stock	0	0
Paid-in capital	257,700	257,026
Accumulated other comprehensive (loss) income	(49,613)	(50,931)
Retained (deficit) earnings	(161,375)	(161,008)
Total stockholders’ equity	46,712	45,087
Total liabilities and stockholders’ equity	46,839	45,213
Eliminations
Current assets:
Cash and cash equivalents	0	0	$ 0	$ 0
Restricted Cash		0
Accounts receivable—oil and gas		(37,822)
Accounts receivable - related parties	0	0
Accounts receivable - intercompany	(482,709)	(450,668)
Prepaid expenses and other current assets	0	0
Short-term derivative instruments	0	0
Total current assets	(482,709)	(488,490)
Property and equipment:
Oil and natural gas properties	(729)	(729)
Other property and equipment	0	0
Accumulated depletion, depreciation, amortization and impairment	0	0
Property and equipment, net	(729)	(729)
Other assets:
Equity investments and investments in subsidiaries	(1,956,591)	(71,210)
Long-term derivative instruments	0	0
Deferred tax asset	0	0
Other assets	0	0
Total other assets	(1,956,591)	(71,210)
Total assets	(2,440,029)	(560,429)
Current liabilities:
Accounts payable and accrued liabilities	0	0
Accounts payable - intercompany	(482,709)	(488,491)
Asset retirement obligation—current	0	0
Derivative instruments	0	0
Current maturities of long-term debt	0	0
Total current liabilities	(482,709)	(488,491)
Long-term derivative instrument	0	0
Asset retirement obligation—long-term	0	0
Long-term debt, net of current maturities	0	0
Total liabilities	(482,709)	(488,491)
Stockholders’ equity:
Common stock	0	0
Paid-in capital	(2,130,298)	(290,848)
Accumulated other comprehensive (loss) income	49,613	50,931
Retained (deficit) earnings	123,365	167,979
Total stockholders’ equity	(1,957,320)	(71,938)
Total liabilities and stockholders’ equity	$ (2,440,029)	$ (560,429)

Condensed Consolidating Finan64

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Total revenues	$ 333,004	$ 156,961
Costs and expenses:
Lease operating expenses	19,303	16,657
Production taxes	3,906	3,111
Midstream gathering and processing	47,941	37,652
Depreciation, depletion and amortization	65,991	65,477
Impairment of oil and gas properties	0	218,991
General and administrative	12,600	10,620
Accretion expense	282	247
Acquisition expense	1,298	0
Total costs and expenses	151,321	352,755
INCOME (LOSS) FROM OPERATIONS	181,683	(195,794)
OTHER (INCOME) EXPENSE:
Interest expense	23,479	16,023
Interest income	(842)	(94)
(Income) loss from equity method investments and investments in subsidiaries	4,907	30,737
Other income	(316)	(2)
Total other (income) expense	27,228	46,664
INCOME (LOSS) BEFORE INCOME TAXES	154,455	(242,458)
INCOME TAX EXPENSE	0	(191)
NET INCOME (LOSS)	154,455	(242,267)
Reportable Legal Entities | Parent
Revenues:
Total revenues	272,441	156,751
Costs and expenses:
Lease operating expenses	17,449	16,472
Production taxes	3,102	3,087
Midstream gathering and processing	37,724	37,623
Depreciation, depletion and amortization	65,990	65,476
Impairment of oil and gas properties		218,991
General and administrative	12,874	10,612
Accretion expense	282	247
Acquisition expense	0
Total costs and expenses	137,421	352,508
INCOME (LOSS) FROM OPERATIONS	135,020	(195,757)
OTHER (INCOME) EXPENSE:
Interest expense	25,048	16,022
Interest income	(842)	(94)
(Income) loss from equity method investments and investments in subsidiaries	(42,614)	30,773
Other income	(1,027)	0
Total other (income) expense	(19,435)	46,701
INCOME (LOSS) BEFORE INCOME TAXES	154,455	(242,458)
INCOME TAX EXPENSE	0	(191)
NET INCOME (LOSS)	154,455	(242,267)
Reportable Legal Entities | Guarantors
Revenues:
Total revenues	60,563	210
Costs and expenses:
Lease operating expenses	1,854	185
Production taxes	804	24
Midstream gathering and processing	10,217	29
Depreciation, depletion and amortization	1	1
Impairment of oil and gas properties		0
General and administrative	(275)	6
Accretion expense	0	0
Acquisition expense	1,298
Total costs and expenses	13,899	245
INCOME (LOSS) FROM OPERATIONS	46,664	(35)
OTHER (INCOME) EXPENSE:
Interest expense	(1,569)	1
Interest income	0	0
(Income) loss from equity method investments and investments in subsidiaries	2,541	0
Other income	(189)	(2)
Total other (income) expense	783	(1)
INCOME (LOSS) BEFORE INCOME TAXES	45,881	(34)
INCOME TAX EXPENSE	0
NET INCOME (LOSS)	45,881	(34)
Reportable Legal Entities | Non-Guarantor
Revenues:
Total revenues	0	0
Costs and expenses:
Lease operating expenses	0	0
Production taxes	0	0
Midstream gathering and processing	0	0
Depreciation, depletion and amortization	0	0
Impairment of oil and gas properties		0
General and administrative	1	2
Accretion expense	0	0
Acquisition expense	0
Total costs and expenses	1	2
INCOME (LOSS) FROM OPERATIONS	(1)	(2)
OTHER (INCOME) EXPENSE:
Interest expense	0	0
Interest income	0	0
(Income) loss from equity method investments and investments in subsidiaries	365	23,685
Other income	0	0
Total other (income) expense	365	23,685
INCOME (LOSS) BEFORE INCOME TAXES	(366)	(23,687)
INCOME TAX EXPENSE	0
NET INCOME (LOSS)	(366)	(23,687)
Eliminations
Revenues:
Total revenues	0	0
Costs and expenses:
Lease operating expenses	0	0
Production taxes	0	0
Midstream gathering and processing	0	0
Depreciation, depletion and amortization	0	0
Impairment of oil and gas properties		0
General and administrative	0	0
Accretion expense	0	0
Acquisition expense	0
Total costs and expenses	0	0
INCOME (LOSS) FROM OPERATIONS	0	0
OTHER (INCOME) EXPENSE:
Interest expense	0	0
Interest income	0	0
(Income) loss from equity method investments and investments in subsidiaries	44,615	(23,721)
Other income	900	0
Total other (income) expense	45,515	(23,721)
INCOME (LOSS) BEFORE INCOME TAXES	(45,515)	23,721
INCOME TAX EXPENSE	0
NET INCOME (LOSS)	$ (45,515)	$ 23,721

Condensed Consolidating Finan65

Condensed Consolidating Financial Information (Condensed Consolidating Statements of Comprehensive Income) (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ 154,455	$ (242,267)
Foreign currency translation adjustment	1,373	9,058
Other comprehensive income	1,373	9,058
Comprehensive income (loss)	155,828	(233,209)
Reportable Legal Entities | Parent
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	154,455	(242,267)
Foreign currency translation adjustment	1,373	9,058
Other comprehensive income	1,373	9,058
Comprehensive income (loss)	155,828	(233,209)
Reportable Legal Entities | Guarantors
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	45,881	(34)
Foreign currency translation adjustment	55	0
Other comprehensive income	55	0
Comprehensive income (loss)	45,936	(34)
Reportable Legal Entities | Non-Guarantor
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(366)	(23,687)
Foreign currency translation adjustment	1,318	10,273
Other comprehensive income	1,318	10,273
Comprehensive income (loss)	952	(13,414)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(45,515)	23,721
Foreign currency translation adjustment	(1,373)	(10,273)
Other comprehensive income	(1,373)	(10,273)
Comprehensive income (loss)	$ (46,888)	$ 13,448

Condensed Consolidating Finan66

Condensed Consolidating Financial Information (Condensed Consolidating Statement of Cash Flows (Details)) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 142,645	$ 83,774
Net cash (used in) provided by investing activities	(1,347,679)	(157,529)
Net cash provided by (used in) financing activities	31,644	415,158
Net (decrease) increase in cash and cash equivalents	(1,173,390)	341,403
Cash and cash equivalents at beginning of period	1,275,875	112,974
Cash and cash equivalents at end of period	102,485	454,377
Reportable Legal Entities | Parent
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	139,260	83,620
Net cash (used in) provided by investing activities	(1,372,852)	(157,529)
Net cash provided by (used in) financing activities	31,644	415,158
Net (decrease) increase in cash and cash equivalents	(1,201,948)	341,249
Cash and cash equivalents at beginning of period	1,273,882	112,494
Cash and cash equivalents at end of period	71,934	453,743
Reportable Legal Entities | Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	3,384	155
Net cash (used in) provided by investing activities	(1,348,964)	(22,500)
Net cash provided by (used in) financing activities	1,374,137	22,500
Net (decrease) increase in cash and cash equivalents	28,557	155
Cash and cash equivalents at beginning of period	1,993	479
Cash and cash equivalents at end of period	30,550	634
Reportable Legal Entities | Non-Guarantor
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	1	(1)
Net cash (used in) provided by investing activities	(673)	(1,821)
Net cash provided by (used in) financing activities	673	1,821
Net (decrease) increase in cash and cash equivalents	1	(1)
Cash and cash equivalents at beginning of period	0	1
Cash and cash equivalents at end of period	1	0
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0
Net cash (used in) provided by investing activities	1,374,810	24,321
Net cash provided by (used in) financing activities	(1,374,810)	(24,321)
Net (decrease) increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) shares in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2017MMBTU / d$ / MMBTUshares	Jun. 30, 2017shares	Apr. 30, 2017MMBTU / d$ / MMBTU	Dec. 31, 2014
2,018
Subsequent Event [Line Items]
Daily Volume | MMBTU / d	30,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.36
NYMEX Henry Hub | 2018
Subsequent Event [Line Items]
Daily Volume | MMBTU / d	543,767
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.09
NYMEX Henry Hub | 2019
Subsequent Event [Line Items]
Daily Volume | MMBTU / d	9,863
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU	3.27
Mammoth Energy Services LP
Subsequent Event [Line Items]
Equity method investment, ownership interest, percent	24.20%			30.50%
Mammoth Energy Partners LP | Sturgeon Acquisitions LLC, Stingray Energy, and Stingray Cementing
Subsequent Event [Line Items]
Shares potentially to be sold (in shares) | shares	7
Subsequent event | NYMEX Henry Hub | 2018
Subsequent Event [Line Items]
Daily Volume | MMBTU / d			65,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU			3.03
Subsequent event | NYMEX Henry Hub | 2019
Subsequent Event [Line Items]
Daily Volume | MMBTU / d			10,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU			3.01
Forecast | Mammoth Energy Services LP
Subsequent Event [Line Items]
Shares received from equity method investee in exchange for ownership interest (in shares) | shares		2
Equity method investment, ownership interest, percent		25.10%