Gulfport Energy (GPOR) 10-Q 9 Aug 17 2017 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 01, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 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	Q2
Entity Common Stock, Shares Outstanding		182,854,921

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 117,555	$ 1,275,875
Restricted cash	0	185,000
Accounts receivable—oil and natural gas	164,154	136,761
Accounts receivable—related parties	185	16
Prepaid expenses and other current assets	4,279	3,135
Short-term derivative instruments	46,416	3,488
Total current assets	332,589	1,604,275
Property and equipment:
Oil and natural gas properties, full-cost accounting, $3,109,143 and $1,580,305 excluded from amortization in 2017 and 2016, respectively	8,500,790	6,071,920
Other property and equipment	79,521	68,986
Accumulated depletion, depreciation, amortization and impairment	(3,937,656)	(3,789,780)
Property and equipment, net	4,642,655	2,351,126
Other assets:
Equity investments	256,265	243,920
Long-term derivative instruments	19,761	5,696
Deferred tax asset	4,692	4,692
Inventories	19,303	4,504
Other assets	18,890	8,932
Total other assets	318,911	267,744
Total assets	5,294,155	4,223,145
Current liabilities:
Accounts payable and accrued liabilities	495,734	265,124
Asset retirement obligation—current	195	195
Short-term derivative instruments	28,106	119,219
Current maturities of long-term debt	595	276
Total current liabilities	524,630	384,814
Long-term derivative instrument	8,198	26,759
Asset retirement obligation—long-term	43,934	34,081
Long-term debt, net of current maturities	1,802,554	1,593,599
Total liabilities	2,379,316	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, 182,854,921 issued and outstanding at June 30, 2017 and 158,829,816 at December 31, 2016	1,828	1,588
Paid-in capital	4,410,871	3,946,442
Accumulated other comprehensive loss	(47,171)	(53,058)
Retained deficit	(1,450,689)	(1,711,080)
Total stockholders’ equity	2,914,839	2,183,892
Total liabilities and stockholders’ equity	$ 5,294,155	$ 4,223,145

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Capitalized costs of oil and natural gas properties excluded from amortization	$ 3,109,143	$ 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)	182,854,921	158,829,816
Common stock, shares, outstanding (shares)	182,854,921	158,829,816

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Natural gas sales	$ 205,367	$ 75,761	$ 383,204	$ 149,855
Oil and condensate sales	29,468	23,161	53,879	39,000
Natural gas liquid sales	24,247	10,311	55,426	19,604
Net gain (loss) on natural gas, oil, and NGL derivatives	64,871	(137,392)	164,448	(79,657)
Total revenues	323,953	(28,159)	656,957	128,802
Costs and expenses:
Lease operating expenses	20,721	14,661	40,024	31,318
Production taxes	5,139	2,856	9,045	5,967
Midstream gathering and processing	58,945	39,349	106,886	77,001
Depreciation, depletion and amortization	82,246	55,652	148,237	121,129
Impairment of oil and natural gas properties	0	170,621	0	389,612
General and administrative	12,257	11,854	24,857	22,474
Accretion expense	410	261	692	508
Acquisition expense	1,060	0	2,358	0
Total costs and expenses	180,778	295,254	332,099	648,009
INCOME (LOSS) FROM OPERATIONS	143,175	(323,413)	324,858	(519,207)
OTHER (INCOME) EXPENSE:
Interest expense	24,188	16,082	47,667	32,105
Interest income	(48)	(391)	(890)	(485)
(Income) loss from equity method investments	13,301	836	18,208	31,573
Other income	(202)	(7)	(518)	(9)
Total other (income) expense	37,239	16,520	64,467	63,184
INCOME (LOSS) BEFORE INCOME TAXES	105,936	(339,933)	260,391	(582,391)
INCOME TAX BENEFIT	0	(157)	0	(348)
NET INCOME (LOSS)	$ 105,936	$ (339,776)	$ 260,391	$ (582,043)
NET INCOME (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ 0.58	$ (2.71)	$ 1.47	$ (4.91)
Diluted (in dollars per share)	$ 0.58	$ (2.71)	$ 1.47	$ (4.91)
Weighted average common shares outstanding - Basic (shares)	182,840,213	125,343,723	176,591,166	118,426,654
Weighted average common shares outstanding - Diluted (shares)	182,841,730	125,343,723	176,842,239	118,426,654

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 105,936	$ (339,776)	$ 260,391	$ (582,043)
Foreign currency translation adjustment	4,514	(684)	5,887	8,374
Other comprehensive income (loss)	4,514	(684)	5,887	8,374
Comprehensive income (loss)	$ 110,450	$ (340,460)	$ 266,278	$ (573,669)

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	(582,043)				(582,043)
Other Comprehensive Income	8,374			8,374
Stock Compensation	6,561		6,561
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	411,711	$ 169	411,542
Issuance of Restricted Stock (in shares)		137,916
Issuance of Restricted Stock	0	$ 2	(2)
Ending Balance (in shares) at Jun. 30, 2016		125,365,166
Ending Balance at Jun. 30, 2016	$ 1,883,440	$ 1,253	3,242,404	(46,803)	(1,313,414)
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	260,391				260,391
Other Comprehensive Income	5,887			5,887
Stock Compensation	5,233		5,233
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	459,436	$ 239	459,197
Issuance of Restricted Stock (in shares)		172,988
Issuance of Restricted Stock	$ 0	$ 1	(1)
Ending Balance (in shares) at Jun. 30, 2017	182,854,921	182,854,921
Ending Balance at Jun. 30, 2017	$ 2,914,839	$ 1,828	$ 4,410,871	$ (47,171)	$ (1,450,689)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ 260,391	$ (582,043)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Accretion of discount—Asset Retirement Obligation	692	508
Depletion, depreciation and amortization	148,237	121,129
Impairment of oil and natural gas properties	0	389,612
Stock-based compensation expense	3,140	3,936
Loss from equity investments	18,662	31,732
Change in fair value of derivative instruments	(166,667)	206,370
Deferred income tax expense (benefit)	0	(348)
Amortization of loan commitment fees	2,288	1,921
Amortization of note discount and premium	0	(1,135)
Changes in operating assets and liabilities:
Increase in accounts receivable	(27,393)	(19,590)
Increase in accounts receivable—related party	(169)	(7)
Increase in prepaid expenses	(1,144)	(3,877)
Increase in other assets	(4,425)	0
Increase (decrease) in accounts payable, accrued liabilities and other	53,385	(5,412)
Settlement of asset retirement obligation	(344)	(72)
Net cash provided by operating activities	286,653	142,724
Cash flows from investing activities:
Deductions to cash held in escrow	0	8
Additions to other property and equipment	(10,645)	(13,410)
Acquisition of oil and natural gas properties	(1,339,222)	0
Additions to oil and natural gas properties	(460,765)	(257,222)
Proceeds from sale of oil and natural gas properties	3,730	1,612
Funding of restricted cash	185,000	0
Contributions to equity method investments	(24,151)	(16,690)
Distributions from equity method investments	1,429	4,658
Net cash used in investing activities	(1,644,624)	(281,044)
Cash flows from financing activities:
Principal payments on borrowings	(47)	(1,685)
Borrowings on line of credit	210,000	0
Borrowings on term loan	2,951	11,962
Debt issuance costs and loan commitment fees	(7,889)	(205)
Proceeds from issuance of common stock, net of offering costs	(5,364)	411,711
Net cash provided by financing activities	199,651	421,783
Net (decrease) increase in cash and cash equivalents	(1,158,320)	283,463
Cash and cash equivalents at beginning of period	1,275,875	112,974
Cash and cash equivalents at end of period	117,555	396,437
Supplemental disclosure of cash flow information:
Interest payments	48,118	35,026
Income tax payments	0	0
Supplemental disclosure of non-cash transactions:
Capitalized stock based compensation	2,093	2,625
Asset retirement obligation capitalized	9,505	3,195
Interest capitalized	6,699	3,707
Foreign currency translation gain on equity method investments	$ 5,887	$ 8,374

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 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 $1.1 million and $2.4 million were incurred during the three and six months ended June 30, 2017 , respectively, 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 three months ended June 30, 2017 and the period from the acquisition date of February 17, 2017 to June 30, 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. Period from February 17, 2017 Three months ended to June 30, 2017 June 30, 2017 (In thousands) Revenue $ 51,069 $ 77,997 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 June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands, except share data) Pro forma revenue $ 323,953 $ (28,012 ) $ 692,856 $ 175,700 Pro forma net income (loss) $ 105,936 $ (461,007 ) $ 281,817 $ (735,214 ) Pro forma earnings (loss) per share (basic) $ 0.58 $ (3.09 ) $ 1.60 $ (5.17 ) Pro forma earnings (loss) per share (diluted) $ 0.58 $ (3.09 ) $ 1.59 $ (5.17 )

Property and Equipment

Property and Equipment	6 Months Ended
	Jun. 30, 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 June 30, 2017 and December 31, 2016 are as follows: June 30, 2017 December 31, 2016 (In thousands) Oil and natural gas properties $ 8,500,790 $ 6,071,920 Office furniture and fixtures 30,227 21,204 Building 44,474 42,530 Land 4,820 5,252 Total property and equipment 8,580,311 6,140,906 Accumulated depletion, depreciation, amortization and impairment (3,937,656 ) (3,789,780 ) Property and equipment, net $ 4,642,655 $ 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 natural gas properties. At June 30, 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 six months ended June 30, 2017 . An impairment of $170.6 million and $389.6 million was required for oil and natural gas properties for the three and six months ended June 30, 2016 , respectively. Included in oil and natural gas properties at June 30, 2017 is the cumulative capitalization of $146.6 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 $8.3 million and $16.7 million for the three and six months ended June 30, 2017 , respectively, and $7.9 million and $15.0 million for the three and six months ended June 30, 2016 , respectively. The following table summarizes the Company’s non-producing properties excluded from amortization by area at June 30, 2017 : June 30, 2017 (In thousands) Utica $ 1,614,824 MidCon 1,491,144 Niobrara 2,173 Southern Louisiana 536 Bakken 98 Other 368 $ 3,109,143 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 six months ended June 30, 2017 and 2016 is as follows: June 30, 2017 June 30, 2016 (In thousands) Asset retirement obligation, beginning of period $ 34,276 $ 26,437 Liabilities incurred 9,505 3,195 Liabilities settled (344 ) (72 ) Accretion expense 692 508 Asset retirement obligation as of end of period 44,129 30,068 Less current portion 195 75 Asset retirement obligation, long-term $ 43,934 $ 29,993

Equity Investments

Equity Investments	6 Months Ended
	Jun. 30, 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 June 30, 2017 and December 31, 2016 : Carrying value (Income) loss from equity method investments Approximate ownership % June 30, 2017 December 31, 2016 Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Investment in Tatex Thailand II, LLC 23.5 % $ — $ — $ (211 ) $ — $ (454 ) $ (159 ) Investment in Tatex Thailand III, LLC 17.9 % — — — — — — Investment in Grizzly Oil Sands ULC 24.9999 % 51,604 45,213 208 763 573 24,448 Investment in Timber Wolf Terminals LLC 50.0 % 987 991 — 1 4 4 Investment in Windsor Midstream LLC 22.5 % 270 25,749 25,545 (2,881 ) 25,234 (3,048 ) Investment in Stingray Cementing LLC (1) — % — 1,920 77 78 205 108 Investment in Blackhawk Midstream LLC 48.5 % — — — — — — Investment in Stingray Energy Services LLC (1) — % — 4,215 85 139 282 641 Investment in Sturgeon Acquisitions LLC (1) — % — 20,526 (139 ) 134 (71 ) 511 Investment in Mammoth Energy Services, Inc. (1) 25.1 % 150,458 111,717 (12,181 ) 2,543 (10,023 ) 9,009 Investment in Strike Force Midstream LLC 25.0 % 52,946 33,589 (83 ) 59 2,458 59 $ 256,265 $ 243,920 $ 13,301 $ 836 $ 18,208 $ 31,573 (1) On June 5, 2017, Mammoth Energy Services, Inc. acquired Stingray Cementing LLC, Stingray Energy Services LLC and Sturgeon Acquisitions LLC. See below under Mammoth Energy Partners LP/Mammoth Energy Services, Inc. for information regarding these transactions. The tables below summarize financial information for the Company’s equity investments as of June 30, 2017 and December 31, 2016 . Summarized balance sheet information: June 30, 2017 December 31, 2016 (In thousands) Current assets $ 145,857 $ 148,733 Noncurrent assets $ 1,414,377 $ 1,305,407 Current liabilities $ 102,011 $ 57,173 Noncurrent liabilities $ 137,215 $ 67,680 Summarized results of operations: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Gross revenue $ 99,640 $ 86,732 $ 194,118 $ 130,039 Net loss $ (67,336 ) $ (560 ) $ (92,675 ) $ (25,868 ) 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 $0.5 million and $0.2 million in distributions from Tatex II during the six months ended June 30, 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 June 30, 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 June 30, 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 six months ended June 30, 2017 , Gulfport paid $1.2 million in cash calls. Grizzly’s functional currency is the Canadian dollar. The Company’s investment in Grizzly was increased by $4.5 million and $5.8 million as a result of a foreign currency translation gain for the three and six months ended June 30, 2017 , respectively. The Company's investment in Grizzly was decreased by $0.6 million as a result of a foreign currency translation loss and increased by $9.7 million as a result of a foreign currency translation gain for the three and six months ended June 30, 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 June 30, 2017 , the Company held a 22.5% interest in Windsor Midstream LLC (“Midstream”), an entity controlled and managed by an unrelated third party. Midstream previously owned a 28.4% interest in Coronado Midstream LLC (“Coronado”), a gas processing plant in West Texas. In March 2015, Coronado was sold to EnLink Midstream Partners, LP (“EnLink”). As a result of the sale of Coronado to EnLink, Midstream received common units of EnLink, which were subsequently sold by Midstream. During the six months ended June 30, 2017, the Company noted that Midstream had not recorded certain activity and fair value treatment of Midstream's investment in EnLink common units in a timely manner. The corresponding effect of this treatment was immaterial to the Company's previously issued financial statements and the recording of the correction in the current periods' financial statements was not material to the Company's estimated net income for the current full fiscal year. For the three and six months ended June 30, 2017, approximately $23.4 million of the loss from equity method investments, net was related to the out-of-period activity associated with the accounting for Midstream's investment in EnLink common units. The Company received $0.2 million and $4.9 million in distributions from Midstream during the six months ended June 30, 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. On June 5, 2017 , Mammoth Energy Services, Inc. (“Mammoth Energy”) acquired Stingray Cementing. See below under Mammoth Energy Partners LP/Mammoth Energy Services, Inc. for information regarding this transaction. 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. On June 5, 2017 , Mammoth Energy acquired Stingray Energy. See below under Mammoth Energy Partners LP/Mammoth Energy Services, Inc. for information regarding this transaction. 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. On June 5, 2017 , Mammoth Energy acquired Sturgeon. See below under Mammoth Energy Partners LP/Mammoth Energy Services, Inc. for information regarding this transaction. 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. 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 . On June 5, 2017 , the Company contributed all of its membership interests in Sturgeon (which owns Taylor Frac, LLC, Taylor Real Estate Investments, LLC and South River Road, LLC), Stingray Energy and Stingray Cementing to Mammoth Energy in exchange for approximately 2.0 million shares of Mammoth Energy common stock. As of June 30, 2017 , the Company held approximately 25.1% of Mammoth Energy’s outstanding common stock. The Company accounted for the transactions as a sale of financial assets under FASB ASC 860. The Company valued the shares of Mammoth Energy common stock it received in the transactions at $18.50 per share, which was the closing price of Mammoth Energy common stock on June 5, 2017 . The Company recognized a gain of $12.5 million from the transactions, which is included in loss from equity method investments, net in the accompanying consolidated statements of operations. The Company’s investment in Mammoth Energy was increased by a $0.02 million and $0.1 million foreign currency gain resulting from Mammoth Energy’s foreign subsidiary for the three and six months ended June 30, 2017 , respectively. The Company's investment in Mammoth Energy was decreased by a $0.1 million and $1.3 million foreign currency loss resulting from Mammoth Energy's foreign subsidiary for the three and six months ended June 30, 2016 , respectively. The (income) loss from equity method investments presented in the table above reflects any intercompany profit eliminations. 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 six months ended June 30, 2017 , Gulfport paid $23.0 million in cash calls to Strike Force and received distributions of $1.2 million from Strike Force. During the six months ended June 30, 2016 , Gulfport paid $3.0 million in cash calls to Strike Force. The Company accounted for its initial 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	6 Months Ended
	Jun. 30, 2017
Related Party Transactions [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES As of June 30, 2017 , the Company held variable interests in the following variable interest entities (“VIEs”), but was not the primary beneficiary: 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. Prior to the contribution of Stingray Energy, Stingray Cementing and Sturgeon to Mammoth Energy, these entities were considered VIEs. As a result of the Company’s contribution of its membership interests in Stingray Energy, Stingray Cementing and Sturgeon to Mammoth Energy in exchange for Mammoth Energy common stock, 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	6 Months Ended
	Jun. 30, 2017
Long-term Debt, Unclassified [Abstract]
Long-Term Debt	LONG-TERM DEBT Long-term debt consisted of the following items as of June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 (In thousands) Revolving credit agreement (1) $ 210,000 $ — 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) (30,804 ) (27,174 ) Construction loan (7) 23,953 21,049 Less: current maturities of long term debt (595 ) (276 ) Debt reflected as long term $ 1,802,554 $ 1,593,599 The Company capitalized approximately $3.6 million and $6.7 million in interest expense to undeveloped oil and natural gas properties during the three and six months ended June 30, 2017 , respectively. The Company capitalized approximately $1.4 million and $3.0 million in interest expense to undeveloped oil and natural gas properties during the three and six months ended June 30, 2016 , respectively. During the three and six months ended June 30, 2016 , the Company also capitalized approximately $0.4 million and $0.7 million , respectively, 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 and six months ended June 30, 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 . 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. As of June 30, 2017 , $210.0 million was outstanding under the revolving credit facility and the total availability for future borrowings under this facility, after giving effect to an aggregate of $237.5 million of letters of credit, was $552.5 million . The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. 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 June 30, 2017 , amounts borrowed under the credit facility bore interest at the eurodollar rate ( 3.46% ). 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 June 30, 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 accrues at a rate of 6.625% per annum on the outstanding principal amount thereof, payable semi-annually on May 1 and November 1 of each year. 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 June 30, 2017 , total unamortized debt issuance costs were $5.6 million for the 2023 Notes, $10.5 million for the 2024 Notes and $14.6 million for the 2025 Notes. In addition, loan commitment fee costs for the construction loan agreement described immediately below were $0.1 million at June 30, 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 was 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 June 30, 2017 , the total borrowings under the Construction Loan were approximately $24.0 million .

Common Stock and Changes In Cap

Common Stock and Changes In Capitalization	6 Months Ended
	Jun. 30, 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 $411.7 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	6 Months Ended
	Jun. 30, 2017
Share-based Compensation [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION During the three and six months ended June 30, 2017 , the Company’s stock-based compensation cost was $2.6 million and $5.2 million , respectively, of which the Company capitalized $1.1 million and $2.1 million , respectively, relating to its exploration and development efforts. During the three and six months ended June 30, 2016 , the Company's stock-based compensation cost was $3.3 million and $6.6 million , respectively, of which the Company capitalized $1.3 million and $2.6 million , respectively, relating to its exploration and development efforts. The following table summarizes restricted stock activity for the six months ended June 30, 2017 : Number of Unvested Restricted Shares Weighted Average Grant Date Fair Value Unvested shares as of January 1, 2017 613,056 $ 32.90 Granted 525,808 17.31 Vested (172,988 ) 32.06 Forfeited (66,661 ) 31.18 Unvested shares as of June 30, 2017 899,215 $ 24.08 Unrecognized compensation expense as of June 30, 2017 related to restricted shares was $16.1 million . The expense is expected to be recognized over a weighted average period of 1.59 years.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 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 June 30, 2017 2016 Income Shares Per Share (Loss) Shares Per Share (In thousands, except share data) Basic: Net income (loss) $ 105,936 182,840,213 $ 0.58 $ (339,776 ) 125,343,723 $ (2.71 ) Effect of dilutive securities: Stock options and awards — 1,517 — — Diluted: — Net income (loss) $ 105,936 182,841,730 $ 0.58 $ (339,776 ) 125,343,723 $ (2.71 ) Six months ended June 30, 2017 2016 Income Shares Per (Loss) Shares Per (In thousands, except share data) Basic: Net income (loss) $ 260,391 176,591,166 $ 1.47 $ (582,043 ) 118,426,654 $ (4.91 ) Effect of dilutive securities: Stock options and awards — 251,073 — — Diluted: — Net income (loss) $ 260,391 176,842,239 $ 1.47 $ (582,043 ) 118,426,654 $ (4.91 ) There were 573,187 and 558,894 shares of common stock that were considered anti-dilutive for the three months and six months ended June 30, 2016 , respectively.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 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 June 30, 2017 , the plugging and abandonment trust totaled approximately $3.1 million . At June 30, 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 June 30, 2017 were as follows: (In thousands) Remaining 2017 $ 70 2018 54 Total $ 124 Firm Transportation Commitments The Company had approximately 2,930,000 MMBtu per day of firm sales contracted with third parties. The table below presents these commitments at June 30, 2017 as follows: (MMBtu per day) Remaining 2017 728,000 2018 498,000 2019 579,000 2020 506,000 2021 371,000 Thereafter 248,000 Total 2,930,000 The Company also had approximately $3.8 billion of firm transportation contracted with third parties. The table below presents these commitments at June 30, 2017 as follows: (In thousands) Remaining 2017 $ 105,871 2018 246,749 2019 243,389 2020 240,746 2021 239,786 Thereafter 2,705,270 Total $ 3,781,811 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 $0.7 million and $2.0 million related to non-utilization fees during the three months and six months ended June 30, 2016 , respectively. The Company did not incur any non-utilization fees during the six months ended June 30, 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 June 30, 2017 are as follows: (In thousands) Remaining 2017 $ 26,220 2018 39,330 Total $ 65,550 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. On July 3, 2017, the Magistrate issued her Report and Recommendation on the Motion to Remand for the Vermillion Parish case, recommending that the plaintiffs' motion to remand be granted. On July 21, 2017, a group of the defendants in the Vermillion Parish case filed objections to the Magistrate’s remand recommendation. 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	6 Months Ended
	Jun. 30, 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 June 30, 2017 . Location Daily Volume (MMBtu/day) Weighted Remaining 2017 NYMEX Henry Hub 681,000 $ 3.20 2018 NYMEX Henry Hub 669,000 $ 3.08 2019 NYMEX Henry Hub 57,000 $ 3.10 Location Daily Volume Weighted Remaining 2017 ARGUS LLS 2,000 $ 53.12 Remaining 2017 NYMEX WTI 5,000 $ 54.89 2018 NYMEX WTI 1,000 $ 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 103,000 $ 3.25 2019 NYMEX Henry Hub 35,000 $ 3.11 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 June 30, 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 12,000 $ (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 June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 (In thousands) Short-term derivative instruments - asset $ 46,416 $ 3,488 Long-term derivative instruments - asset $ 19,761 $ 5,696 Short-term derivative instruments - liability $ 28,106 $ 119,219 Long-term derivative instruments - liability $ 8,198 $ 26,759 Gains and Losses The following table presents the gain and loss recognized in Net gain (loss) on natural gas, oil and NGL derivatives in the accompanying consolidated statements of operations for the three and six months ended June 30, 2017 and 2016 . Net gain (loss) on derivative instruments Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Natural gas derivatives $ 56,668 $ (133,621 ) $ 142,945 $ (76,621 ) Oil derivatives 8,143 (2,628 ) 19,048 (1,346 ) Natural gas liquids derivatives 60 (1,143 ) 2,455 (1,690 ) Total $ 64,871 $ (137,392 ) $ 164,448 $ (79,657 ) 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 June 30, 2017 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 66,177 $ (27,984 ) $ 38,193 Derivative liabilities $ (36,304 ) $ 27,984 $ (8,320 ) 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	6 Months Ended
	Jun. 30, 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 June 30, 2017 and December 31, 2016 : June 30, 2017 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 66,177 $ — Liabilities: Derivative Instruments $ — $ 36,304 $ — 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 natural 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 natural 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 six months ended June 30, 2017 were approximately $9.5 million . The fair value of the common stock received from Mammoth Energy in connection with the Company’s contribution of all of its membership interests in Sturgeon, Stingray Energy and Stingray Cementing was estimated using Level 1 inputs, as the price per share was a quoted price in an active market for identical Mammoth Energy common shares. 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 initial 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	6 Months Ended
	Jun. 30, 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 June 30, 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 $5.6 million related to the 2023 Notes, approximately $10.5 million related to the 2024 Notes and approximately $14.6 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 June 30, 2017 .

Condensed Consolidating Financi

Condensed Consolidating Financial Information	6 Months Ended
	Jun. 30, 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) June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 72,062 $ 45,493 $ — $ — $ 117,555 Accounts receivable - oil and natural gas 121,565 42,589 — — 164,154 Accounts receivable - related parties 185 — — — 185 Accounts receivable - intercompany 459,503 45,749 — (505,252 ) — Prepaid expenses and other current assets 4,113 166 — — 4,279 Short-term derivative instruments 46,416 — — — 46,416 Total current assets 703,844 133,997 — (505,252 ) 332,589 Property and equipment: Oil and natural gas properties, full-cost accounting 6,142,757 2,358,762 — (729 ) 8,500,790 Other property and equipment 79,478 43 — — 79,521 Accumulated depletion, depreciation, amortization and impairment (3,937,621 ) (35 ) — — (3,937,656 ) Property and equipment, net 2,284,614 2,358,770 — (729 ) 4,642,655 Other assets: Equity investments and investments in subsidiaries 2,179,931 52,946 51,605 (2,028,217 ) 256,265 Long-term derivative instruments 19,761 — — — 19,761 Deferred tax asset 4,692 — — — 4,692 Inventories 13,591 5,712 — — 19,303 Other assets 10,834 8,056 — — 18,890 Total other assets 2,228,809 66,714 51,605 (2,028,217 ) 318,911 Total assets $ 5,217,267 $ 2,559,481 $ 51,605 $ (2,534,198 ) $ 5,294,155 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 385,908 $ 109,826 $ — $ — $ 495,734 Accounts payable - intercompany 39,564 465,561 127 (505,252 ) — Asset retirement obligation - current 195 — — — 195 Derivative instruments 28,106 — — — 28,106 Current maturities of long-term debt 595 — — — 595 Total current liabilities 454,368 575,387 127 (505,252 ) 524,630 Long-term derivative instrument 8,198 — — — 8,198 Asset retirement obligation - long-term 37,308 6,626 — — 43,934 Long-term debt, net of current maturities 1,802,554 — — — 1,802,554 Total liabilities 2,302,428 582,013 127 (505,252 ) 2,379,316 Stockholders’ equity: Common stock 1,828 — — — 1,828 Paid-in capital 4,410,871 1,885,598 258,178 (2,143,776 ) 4,410,871 Accumulated other comprehensive (loss) income (47,171 ) — (45,117 ) 45,117 (47,171 ) Retained (deficit) earnings (1,450,689 ) 91,870 (161,583 ) 69,713 (1,450,689 ) Total stockholders’ equity 2,914,839 1,977,468 51,478 (2,028,946 ) 2,914,839 Total liabilities and stockholders ’ equity $ 5,217,267 $ 2,559,481 $ 51,605 $ (2,534,198 ) $ 5,294,155 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 natural 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 3,135 — — — 3,135 Short-term derivative instruments 3,488 — — — 3,488 Total current assets 2,052,125 40,640 — (488,490 ) 1,604,275 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 Inventories 3,095 1,409 — — 4,504 Other assets 8,932 — — — 8,932 Total other assets 258,742 34,999 45,213 (71,210 ) 267,744 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 - current 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 - long-term 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 June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 249,353 $ 74,600 $ — $ — $ 323,953 Costs and expenses: Lease operating expenses 16,423 4,298 — — 20,721 Production taxes 3,645 1,494 — — 5,139 Midstream gathering and processing 42,291 16,654 — — 58,945 Depreciation, depletion, and amortization 82,245 1 — — 82,246 General and administrative 13,052 (796 ) 1 — 12,257 Accretion expense 291 119 — — 410 Acquisition expense 5 1,055 — — 1,060 157,952 22,825 1 — 180,778 INCOME (LOSS) FROM OPERATIONS 91,401 51,775 (1 ) — 143,175 OTHER (INCOME) EXPENSE: Interest expense 26,133 (1,945 ) — — 24,188 Interest income (42 ) (6 ) — — (48 ) (Income) loss from equity method investments and investments in subsidiaries (40,475 ) (83 ) 208 53,651 13,301 Other income (151 ) (51 ) — — (202 ) (14,535 ) (2,085 ) 208 53,651 37,239 INCOME (LOSS) BEFORE INCOME TAXES 105,936 53,860 (209 ) (53,651 ) 105,936 INCOME TAX EXPENSE — — — — — NET INCOME (LOSS) $ 105,936 $ 53,860 $ (209 ) $ (53,651 ) $ 105,936 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ (28,580 ) $ 421 $ — $ — $ (28,159 ) Costs and expenses: Lease operating expenses 14,491 170 — — 14,661 Production taxes 2,828 28 — — 2,856 Midstream gathering and processing 39,242 107 — — 39,349 Depreciation, depletion, and amortization 55,651 1 — — 55,652 Impairment of oil and natural gas properties 170,621 — — — 170,621 General and administrative 11,846 8 — — 11,854 Accretion expense 261 — — — 261 294,940 314 — — 295,254 (LOSS) INCOME FROM OPERATIONS (323,520 ) 107 — — (323,413 ) OTHER (INCOME) EXPENSE: Interest expense 16,082 — — — 16,082 Interest income (391 ) — — — (391 ) Loss (income) from equity method investments and investments in subsidiaries 722 59 762 (707 ) 836 Other income — (7 ) — — (7 ) 16,413 52 762 (707 ) 16,520 (LOSS) INCOME BEFORE INCOME TAXES (339,933 ) 55 (762 ) 707 (339,933 ) INCOME TAX BENEFIT (157 ) — — — (157 ) NET (LOSS) INCOME $ (339,776 ) $ 55 $ (762 ) $ 707 $ (339,776 ) CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Six months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 521,794 $ 135,163 $ — $ — $ 656,957 Costs and expenses: Lease operating expenses 33,872 6,152 — — 40,024 Production taxes 6,747 2,298 — — 9,045 Midstream gathering and processing 80,015 26,871 — — 106,886 Depreciation, depletion, and amortization 148,235 2 — — 148,237 General and administrative 25,926 (1,071 ) 2 — 24,857 Accretion expense 573 119 — — 692 Acquisition expense 5 2,353 — — 2,358 295,373 36,724 2 — 332,099 INCOME (LOSS) FROM OPERATIONS 226,421 98,439 (2 ) — 324,858 OTHER (INCOME) EXPENSE: Interest expense 51,181 (3,514 ) — — 47,667 Interest income (884 ) (6 ) — — (890 ) (Income) loss from equity method investments and investments in subsidiaries (83,089 ) 2,458 573 98,266 18,208 Other (income) expense (1,178 ) (240 ) — 900 (518 ) (33,970 ) (1,302 ) 573 99,166 64,467 INCOME (LOSS) BEFORE INCOME TAXES 260,391 99,741 (575 ) (99,166 ) 260,391 INCOME TAX BENEFIT — — — — — NET INCOME (LOSS) $ 260,391 $ 99,741 $ (575 ) $ (99,166 ) $ 260,391 Six months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 128,171 $ 631 $ — $ — $ 128,802 Costs and expenses: Lease operating expenses 30,963 355 — — 31,318 Production taxes 5,915 52 — — 5,967 Midstream gathering and processing 76,865 136 — — 77,001 Depreciation, depletion, and amortization 121,127 2 121,129 Impairment of oil and natural gas properties 389,612 — — — 389,612 General and administrative 22,458 14 2 — 22,474 Accretion expense 508 — — — 508 647,448 559 2 — 648,009 (LOSS) INCOME FROM OPERATIONS (519,277 ) 72 (2 ) — (519,207 ) OTHER (INCOME) EXPENSE: Interest expense 32,104 1 — — 32,105 Interest income (485 ) — — — (485 ) Loss (income) from equity method investments and investments in subsidiaries 31,495 59 24,447 (24,428 ) 31,573 Other income — (9 ) — — (9 ) 63,114 51 24,447 (24,428 ) 63,184 (LOSS) INCOME BEFORE INCOME TAXES (582,391 ) 21 (24,449 ) 24,428 (582,391 ) INCOME TAX BENEFIT (348 ) — — — (348 ) NET (LOSS) INCOME $ (582,043 ) $ 21 $ (24,449 ) $ 24,428 $ (582,043 ) CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Amounts in thousands) Three months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 105,936 $ 53,860 $ (209 ) $ (53,651 ) $ 105,936 Foreign currency translation adjustment 4,514 19 4,495 (4,514 ) 4,514 Other comprehensive income (loss) 4,514 19 4,495 (4,514 ) 4,514 Comprehensive income (loss) $ 110,450 $ 53,879 $ 4,286 $ (58,165 ) $ 110,450 Three months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net (loss) income $ (339,776 ) $ 55 $ (762 ) $ 707 $ (339,776 ) Foreign currency translation adjustment (684 ) — (604 ) 604 (684 ) Other comprehensive (loss) income (684 ) — (604 ) 604 (684 ) Comprehensive (loss) income $ (340,460 ) $ 55 $ (1,366 ) $ 1,311 $ (340,460 ) Six months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 260,391 $ 99,741 $ (575 ) $ (99,166 ) $ 260,391 Foreign currency translation adjustment 5,887 74 5,813 (5,887 ) 5,887 Other comprehensive income (loss) 5,887 74 5,813 (5,887 ) 5,887 Comprehensive income (loss) $ 266,278 $ 99,815 $ 5,238 $ (105,053 ) $ 266,278 Six months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net (loss) income $ (582,043 ) $ 21 $ (24,449 ) $ 24,428 $ (582,043 ) Foreign currency translation adjustment 8,374 — 9,669 (9,669 ) 8,374 Other comprehensive income (loss) 8,374 — 9,669 (9,669 ) 8,374 Comprehensive (loss) income $ (573,669 ) $ 21 $ (14,780 ) $ 14,759 $ (573,669 ) CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Amounts in thousands) Six months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 268,068 $ 18,585 $ 1 $ (1 ) $ 286,653 Net cash (used in) provided by investing activities (1,669,539 ) (1,362,222 ) (1,151 ) 1,388,288 (1,644,624 ) Net cash provided by (used in) financing activities 199,651 1,387,137 1,150 (1,388,287 ) 199,651 Net (decrease) increase in cash and cash equivalents (1,201,820 ) 43,500 — — (1,158,320 ) Cash and cash equivalents at beginning of period 1,273,882 1,993 — — 1,275,875 Cash and cash equivalents at end of period $ 72,062 $ 45,493 $ — $ — $ 117,555 Six months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by operating activities $ 142,470 $ 254 $ — $ — $ 142,724 Net cash (used in) provided by investing activities (281,044 ) (25,500 ) (13,690 ) 39,190 (281,044 ) Net cash provided by (used in) financing activities 421,783 25,500 13,690 (39,190 ) 421,783 Net increase in cash and cash equivalents 283,209 254 — — 283,463 Cash and cash equivalents at beginning of period 112,494 479 1 — 112,974 Cash and cash equivalents at end of period $ 395,703 $ 733 $ 1 $ — $ 396,437

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 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 working to identify any potential differences that would result from applying the requirements of the ASU to existing contracts and current accounting policies and practices. This evaluation includes the review of contracts for each revenue stream identified within the Company's business. The Company will conduct its contract review process throughout the remainder of 2017. Based on the continuing evaluation of its revenue streams, this ASU is not expected to have a material impact on the Company's 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 and does not plan to early adopt this guidance. 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	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Derivatives In July and August 2017, the Company entered into fixed price swaps for 2017 for approximately 66,000 MMBtu of natural gas per day at a weighted average price of $3.08 per MMBtu. For 2018, the Company entered into fixed price swaps for approximately 105,000 MMBtu of natural gas per day at a weighted average price of $2.94 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. In July and August 2017, the Company sold call options for 2019 for approximately 50,000 MMBtu of natural gas per day at a weighted average price of $3.04 per MMBtu. 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. Registration Rights Agreements As required under the terms of the registration rights agreements relating to the 2024 Notes and the 2025 Notes, on July 7, 2017, the Company filed with the SEC a Registration Statement on Form S-4 (the “Registration Statement”), relating to the exchange offers of the 2024 Notes and the 2025 Notes for substantially identical notes registered under the Securities Act (the “Exchange Offers”). The Registration Statement was declared effective by the SEC on August 4, 2017. The Company commenced the Exchange Offers on August 8, 2017 and expects to close the Exchange Offers in September of 2017.

Recent Accounting Pronounceme23

Recent Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 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 working to identify any potential differences that would result from applying the requirements of the ASU to existing contracts and current accounting policies and practices. This evaluation includes the review of contracts for each revenue stream identified within the Company's business. The Company will conduct its contract review process throughout the remainder of 2017. Based on the continuing evaluation of its revenue streams, this ASU is not expected to have a material impact on the Company's 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 and does not plan to early adopt this guidance. 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)	6 Months Ended
	Jun. 30, 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 three months ended June 30, 2017 and the period from the acquisition date of February 17, 2017 to June 30, 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. Period from February 17, 2017 Three months ended to June 30, 2017 June 30, 2017 (In thousands) Revenue $ 51,069 $ 77,997 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 June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands, except share data) Pro forma revenue $ 323,953 $ (28,012 ) $ 692,856 $ 175,700 Pro forma net income (loss) $ 105,936 $ (461,007 ) $ 281,817 $ (735,214 ) Pro forma earnings (loss) per share (basic) $ 0.58 $ (3.09 ) $ 1.60 $ (5.17 ) Pro forma earnings (loss) per share (diluted) $ 0.58 $ (3.09 ) $ 1.59 $ (5.17 )

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 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 June 30, 2017 and December 31, 2016 are as follows: June 30, 2017 December 31, 2016 (In thousands) Oil and natural gas properties $ 8,500,790 $ 6,071,920 Office furniture and fixtures 30,227 21,204 Building 44,474 42,530 Land 4,820 5,252 Total property and equipment 8,580,311 6,140,906 Accumulated depletion, depreciation, amortization and impairment (3,937,656 ) (3,789,780 ) Property and equipment, net $ 4,642,655 $ 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 June 30, 2017 : June 30, 2017 (In thousands) Utica $ 1,614,824 MidCon 1,491,144 Niobrara 2,173 Southern Louisiana 536 Bakken 98 Other 368 $ 3,109,143
Schedule of Asset Retirement Obligation	A reconciliation of the Company’s asset retirement obligation for the six months ended June 30, 2017 and 2016 is as follows: June 30, 2017 June 30, 2016 (In thousands) Asset retirement obligation, beginning of period $ 34,276 $ 26,437 Liabilities incurred 9,505 3,195 Liabilities settled (344 ) (72 ) Accretion expense 692 508 Asset retirement obligation as of end of period 44,129 30,068 Less current portion 195 75 Asset retirement obligation, long-term $ 43,934 $ 29,993

Equity Investments (Tables)

Equity Investments (Tables)	6 Months Ended
	Jun. 30, 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 June 30, 2017 and December 31, 2016 : Carrying value (Income) loss from equity method investments Approximate ownership % June 30, 2017 December 31, 2016 Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Investment in Tatex Thailand II, LLC 23.5 % $ — $ — $ (211 ) $ — $ (454 ) $ (159 ) Investment in Tatex Thailand III, LLC 17.9 % — — — — — — Investment in Grizzly Oil Sands ULC 24.9999 % 51,604 45,213 208 763 573 24,448 Investment in Timber Wolf Terminals LLC 50.0 % 987 991 — 1 4 4 Investment in Windsor Midstream LLC 22.5 % 270 25,749 25,545 (2,881 ) 25,234 (3,048 ) Investment in Stingray Cementing LLC (1) — % — 1,920 77 78 205 108 Investment in Blackhawk Midstream LLC 48.5 % — — — — — — Investment in Stingray Energy Services LLC (1) — % — 4,215 85 139 282 641 Investment in Sturgeon Acquisitions LLC (1) — % — 20,526 (139 ) 134 (71 ) 511 Investment in Mammoth Energy Services, Inc. (1) 25.1 % 150,458 111,717 (12,181 ) 2,543 (10,023 ) 9,009 Investment in Strike Force Midstream LLC 25.0 % 52,946 33,589 (83 ) 59 2,458 59 $ 256,265 $ 243,920 $ 13,301 $ 836 $ 18,208 $ 31,573 (1) On June 5, 2017, Mammoth Energy Services, Inc. acquired Stingray Cementing LLC, Stingray Energy Services LLC and Sturgeon Acquisitions LLC. See below under Mammoth Energy Partners LP/Mammoth Energy Services, Inc. for information regarding these transactions.
Equity Method Investment Balance Sheet Summary	The tables below summarize financial information for the Company’s equity investments as of June 30, 2017 and December 31, 2016 . Summarized balance sheet information: June 30, 2017 December 31, 2016 (In thousands) Current assets $ 145,857 $ 148,733 Noncurrent assets $ 1,414,377 $ 1,305,407 Current liabilities $ 102,011 $ 57,173 Noncurrent liabilities $ 137,215 $ 67,680
Equity Method Investment Income Statement Summary	Summarized results of operations: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Gross revenue $ 99,640 $ 86,732 $ 194,118 $ 130,039 Net loss $ (67,336 ) $ (560 ) $ (92,675 ) $ (25,868 )

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2017
Long-term Debt, Unclassified [Abstract]
Break-Down of Long-Term Debt	Long-term debt consisted of the following items as of June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 (In thousands) Revolving credit agreement (1) $ 210,000 $ — 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) (30,804 ) (27,174 ) Construction loan (7) 23,953 21,049 Less: current maturities of long term debt (595 ) (276 ) Debt reflected as long term $ 1,802,554 $ 1,593,599 The Company capitalized approximately $3.6 million and $6.7 million in interest expense to undeveloped oil and natural gas properties during the three and six months ended June 30, 2017 , respectively. The Company capitalized approximately $1.4 million and $3.0 million in interest expense to undeveloped oil and natural gas properties during the three and six months ended June 30, 2016 , respectively. During the three and six months ended June 30, 2016 , the Company also capitalized approximately $0.4 million and $0.7 million , respectively, 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 and six months ended June 30, 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 . 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. As of June 30, 2017 , $210.0 million was outstanding under the revolving credit facility and the total availability for future borrowings under this facility, after giving effect to an aggregate of $237.5 million of letters of credit, was $552.5 million . The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. 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 June 30, 2017 , amounts borrowed under the credit facility bore interest at the eurodollar rate ( 3.46% ). 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 June 30, 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 accrues at a rate of 6.625% per annum on the outstanding principal amount thereof, payable semi-annually on May 1 and November 1 of each year. 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 June 30, 2017 , total unamortized debt issuance costs were $5.6 million for the 2023 Notes, $10.5 million for the 2024 Notes and $14.6 million for the 2025 Notes. In addition, loan commitment fee costs for the construction loan agreement described immediately below were $0.1 million at June 30, 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 was 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 June 30, 2017 , the total borrowings under the Construction Loan were approximately $24.0 million .

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Share-based Compensation [Abstract]
Summary of Restricted Stock Award and Unit Activity	The following table summarizes restricted stock activity for the six months ended June 30, 2017 : Number of Unvested Restricted Shares Weighted Average Grant Date Fair Value Unvested shares as of January 1, 2017 613,056 $ 32.90 Granted 525,808 17.31 Vested (172,988 ) 32.06 Forfeited (66,661 ) 31.18 Unvested shares as of June 30, 2017 899,215 $ 24.08

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 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 June 30, 2017 2016 Income Shares Per Share (Loss) Shares Per Share (In thousands, except share data) Basic: Net income (loss) $ 105,936 182,840,213 $ 0.58 $ (339,776 ) 125,343,723 $ (2.71 ) Effect of dilutive securities: Stock options and awards — 1,517 — — Diluted: — Net income (loss) $ 105,936 182,841,730 $ 0.58 $ (339,776 ) 125,343,723 $ (2.71 ) Six months ended June 30, 2017 2016 Income Shares Per (Loss) Shares Per (In thousands, except share data) Basic: Net income (loss) $ 260,391 176,591,166 $ 1.47 $ (582,043 ) 118,426,654 $ (4.91 ) Effect of dilutive securities: Stock options and awards — 251,073 — — Diluted: — Net income (loss) $ 260,391 176,842,239 $ 1.47 $ (582,043 ) 118,426,654 $ (4.91 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2017
Long-term Purchase Commitment [Line Items]
Schedule of Future Minimum Lease Commitments	Future minimum lease commitments under these leases at June 30, 2017 were as follows: (In thousands) Remaining 2017 $ 70 2018 54 Total $ 124
Schedule of Firm Transportation Commitments	The table below presents these commitments at June 30, 2017 as follows: (MMBtu per day) Remaining 2017 728,000 2018 498,000 2019 579,000 2020 506,000 2021 371,000 Thereafter 248,000 Total 2,930,000
Transportation commitment
Long-term Purchase Commitment [Line Items]
Schedule of Other Commitments	The table below presents these commitments at June 30, 2017 as follows: (In thousands) Remaining 2017 $ 105,871 2018 246,749 2019 243,389 2020 240,746 2021 239,786 Thereafter 2,705,270 Total $ 3,781,811
Purchase commitment
Long-term Purchase Commitment [Line Items]
Schedule of Other Commitments	Future minimum commitments under these agreements at June 30, 2017 are as follows: (In thousands) Remaining 2017 $ 26,220 2018 39,330 Total $ 65,550

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 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 June 30, 2017 . Location Daily Volume (MMBtu/day) Weighted Remaining 2017 NYMEX Henry Hub 681,000 $ 3.20 2018 NYMEX Henry Hub 669,000 $ 3.08 2019 NYMEX Henry Hub 57,000 $ 3.10 Location Daily Volume Weighted Remaining 2017 ARGUS LLS 2,000 $ 53.12 Remaining 2017 NYMEX WTI 5,000 $ 54.89 2018 NYMEX WTI 1,000 $ 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 103,000 $ 3.25 2019 NYMEX Henry Hub 35,000 $ 3.11
Schedule of Natural Gas Basis Swap Position Derivatives	As of June 30, 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 12,000 $ (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 June 30, 2017 and December 31, 2016 : June 30, 2017 December 31, 2016 (In thousands) Short-term derivative instruments - asset $ 46,416 $ 3,488 Long-term derivative instruments - asset $ 19,761 $ 5,696 Short-term derivative instruments - liability $ 28,106 $ 119,219 Long-term derivative instruments - liability $ 8,198 $ 26,759
Schedule of Cash Flow Hedges	The following table presents the gain and loss recognized in Net gain (loss) on natural gas, oil and NGL derivatives in the accompanying consolidated statements of operations for the three and six months ended June 30, 2017 and 2016 . Net gain (loss) on derivative instruments Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Natural gas derivatives $ 56,668 $ (133,621 ) $ 142,945 $ (76,621 ) Oil derivatives 8,143 (2,628 ) 19,048 (1,346 ) Natural gas liquids derivatives 60 (1,143 ) 2,455 (1,690 ) Total $ 64,871 $ (137,392 ) $ 164,448 $ (79,657 )
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 June 30, 2017 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 66,177 $ (27,984 ) $ 38,193 Derivative liabilities $ (36,304 ) $ 27,984 $ (8,320 ) 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 June 30, 2017 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 66,177 $ (27,984 ) $ 38,193 Derivative liabilities $ (36,304 ) $ 27,984 $ (8,320 ) 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)	6 Months Ended
	Jun. 30, 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 June 30, 2017 and December 31, 2016 : June 30, 2017 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 66,177 $ — Liabilities: Derivative Instruments $ — $ 36,304 $ — 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)	6 Months Ended
	Jun. 30, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Balance Sheets	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) June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 72,062 $ 45,493 $ — $ — $ 117,555 Accounts receivable - oil and natural gas 121,565 42,589 — — 164,154 Accounts receivable - related parties 185 — — — 185 Accounts receivable - intercompany 459,503 45,749 — (505,252 ) — Prepaid expenses and other current assets 4,113 166 — — 4,279 Short-term derivative instruments 46,416 — — — 46,416 Total current assets 703,844 133,997 — (505,252 ) 332,589 Property and equipment: Oil and natural gas properties, full-cost accounting 6,142,757 2,358,762 — (729 ) 8,500,790 Other property and equipment 79,478 43 — — 79,521 Accumulated depletion, depreciation, amortization and impairment (3,937,621 ) (35 ) — — (3,937,656 ) Property and equipment, net 2,284,614 2,358,770 — (729 ) 4,642,655 Other assets: Equity investments and investments in subsidiaries 2,179,931 52,946 51,605 (2,028,217 ) 256,265 Long-term derivative instruments 19,761 — — — 19,761 Deferred tax asset 4,692 — — — 4,692 Inventories 13,591 5,712 — — 19,303 Other assets 10,834 8,056 — — 18,890 Total other assets 2,228,809 66,714 51,605 (2,028,217 ) 318,911 Total assets $ 5,217,267 $ 2,559,481 $ 51,605 $ (2,534,198 ) $ 5,294,155 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 385,908 $ 109,826 $ — $ — $ 495,734 Accounts payable - intercompany 39,564 465,561 127 (505,252 ) — Asset retirement obligation - current 195 — — — 195 Derivative instruments 28,106 — — — 28,106 Current maturities of long-term debt 595 — — — 595 Total current liabilities 454,368 575,387 127 (505,252 ) 524,630 Long-term derivative instrument 8,198 — — — 8,198 Asset retirement obligation - long-term 37,308 6,626 — — 43,934 Long-term debt, net of current maturities 1,802,554 — — — 1,802,554 Total liabilities 2,302,428 582,013 127 (505,252 ) 2,379,316 Stockholders’ equity: Common stock 1,828 — — — 1,828 Paid-in capital 4,410,871 1,885,598 258,178 (2,143,776 ) 4,410,871 Accumulated other comprehensive (loss) income (47,171 ) — (45,117 ) 45,117 (47,171 ) Retained (deficit) earnings (1,450,689 ) 91,870 (161,583 ) 69,713 (1,450,689 ) Total stockholders’ equity 2,914,839 1,977,468 51,478 (2,028,946 ) 2,914,839 Total liabilities and stockholders ’ equity $ 5,217,267 $ 2,559,481 $ 51,605 $ (2,534,198 ) $ 5,294,155 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 natural 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 3,135 — — — 3,135 Short-term derivative instruments 3,488 — — — 3,488 Total current assets 2,052,125 40,640 — (488,490 ) 1,604,275 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 Inventories 3,095 1,409 — — 4,504 Other assets 8,932 — — — 8,932 Total other assets 258,742 34,999 45,213 (71,210 ) 267,744 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 - current 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 - long-term 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 June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 249,353 $ 74,600 $ — $ — $ 323,953 Costs and expenses: Lease operating expenses 16,423 4,298 — — 20,721 Production taxes 3,645 1,494 — — 5,139 Midstream gathering and processing 42,291 16,654 — — 58,945 Depreciation, depletion, and amortization 82,245 1 — — 82,246 General and administrative 13,052 (796 ) 1 — 12,257 Accretion expense 291 119 — — 410 Acquisition expense 5 1,055 — — 1,060 157,952 22,825 1 — 180,778 INCOME (LOSS) FROM OPERATIONS 91,401 51,775 (1 ) — 143,175 OTHER (INCOME) EXPENSE: Interest expense 26,133 (1,945 ) — — 24,188 Interest income (42 ) (6 ) — — (48 ) (Income) loss from equity method investments and investments in subsidiaries (40,475 ) (83 ) 208 53,651 13,301 Other income (151 ) (51 ) — — (202 ) (14,535 ) (2,085 ) 208 53,651 37,239 INCOME (LOSS) BEFORE INCOME TAXES 105,936 53,860 (209 ) (53,651 ) 105,936 INCOME TAX EXPENSE — — — — — NET INCOME (LOSS) $ 105,936 $ 53,860 $ (209 ) $ (53,651 ) $ 105,936 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ (28,580 ) $ 421 $ — $ — $ (28,159 ) Costs and expenses: Lease operating expenses 14,491 170 — — 14,661 Production taxes 2,828 28 — — 2,856 Midstream gathering and processing 39,242 107 — — 39,349 Depreciation, depletion, and amortization 55,651 1 — — 55,652 Impairment of oil and natural gas properties 170,621 — — — 170,621 General and administrative 11,846 8 — — 11,854 Accretion expense 261 — — — 261 294,940 314 — — 295,254 (LOSS) INCOME FROM OPERATIONS (323,520 ) 107 — — (323,413 ) OTHER (INCOME) EXPENSE: Interest expense 16,082 — — — 16,082 Interest income (391 ) — — — (391 ) Loss (income) from equity method investments and investments in subsidiaries 722 59 762 (707 ) 836 Other income — (7 ) — — (7 ) 16,413 52 762 (707 ) 16,520 (LOSS) INCOME BEFORE INCOME TAXES (339,933 ) 55 (762 ) 707 (339,933 ) INCOME TAX BENEFIT (157 ) — — — (157 ) NET (LOSS) INCOME $ (339,776 ) $ 55 $ (762 ) $ 707 $ (339,776 ) CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Six months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 521,794 $ 135,163 $ — $ — $ 656,957 Costs and expenses: Lease operating expenses 33,872 6,152 — — 40,024 Production taxes 6,747 2,298 — — 9,045 Midstream gathering and processing 80,015 26,871 — — 106,886 Depreciation, depletion, and amortization 148,235 2 — — 148,237 General and administrative 25,926 (1,071 ) 2 — 24,857 Accretion expense 573 119 — — 692 Acquisition expense 5 2,353 — — 2,358 295,373 36,724 2 — 332,099 INCOME (LOSS) FROM OPERATIONS 226,421 98,439 (2 ) — 324,858 OTHER (INCOME) EXPENSE: Interest expense 51,181 (3,514 ) — — 47,667 Interest income (884 ) (6 ) — — (890 ) (Income) loss from equity method investments and investments in subsidiaries (83,089 ) 2,458 573 98,266 18,208 Other (income) expense (1,178 ) (240 ) — 900 (518 ) (33,970 ) (1,302 ) 573 99,166 64,467 INCOME (LOSS) BEFORE INCOME TAXES 260,391 99,741 (575 ) (99,166 ) 260,391 INCOME TAX BENEFIT — — — — — NET INCOME (LOSS) $ 260,391 $ 99,741 $ (575 ) $ (99,166 ) $ 260,391 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Six months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 128,171 $ 631 $ — $ — $ 128,802 Costs and expenses: Lease operating expenses 30,963 355 — — 31,318 Production taxes 5,915 52 — — 5,967 Midstream gathering and processing 76,865 136 — — 77,001 Depreciation, depletion, and amortization 121,127 2 121,129 Impairment of oil and natural gas properties 389,612 — — — 389,612 General and administrative 22,458 14 2 — 22,474 Accretion expense 508 — — — 508 647,448 559 2 — 648,009 (LOSS) INCOME FROM OPERATIONS (519,277 ) 72 (2 ) — (519,207 ) OTHER (INCOME) EXPENSE: Interest expense 32,104 1 — — 32,105 Interest income (485 ) — — — (485 ) Loss (income) from equity method investments and investments in subsidiaries 31,495 59 24,447 (24,428 ) 31,573 Other income — (9 ) — — (9 ) 63,114 51 24,447 (24,428 ) 63,184 (LOSS) INCOME BEFORE INCOME TAXES (582,391 ) 21 (24,449 ) 24,428 (582,391 ) INCOME TAX BENEFIT (348 ) — — — (348 ) NET (LOSS) INCOME $ (582,043 ) $ 21 $ (24,449 ) $ 24,428 $ (582,043 )
Condensed Consolidating Statements of Comprehensive Income (Loss)	CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Amounts in thousands) Three months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 105,936 $ 53,860 $ (209 ) $ (53,651 ) $ 105,936 Foreign currency translation adjustment 4,514 19 4,495 (4,514 ) 4,514 Other comprehensive income (loss) 4,514 19 4,495 (4,514 ) 4,514 Comprehensive income (loss) $ 110,450 $ 53,879 $ 4,286 $ (58,165 ) $ 110,450 Three months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net (loss) income $ (339,776 ) $ 55 $ (762 ) $ 707 $ (339,776 ) Foreign currency translation adjustment (684 ) — (604 ) 604 (684 ) Other comprehensive (loss) income (684 ) — (604 ) 604 (684 ) Comprehensive (loss) income $ (340,460 ) $ 55 $ (1,366 ) $ 1,311 $ (340,460 ) Six months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 260,391 $ 99,741 $ (575 ) $ (99,166 ) $ 260,391 Foreign currency translation adjustment 5,887 74 5,813 (5,887 ) 5,887 Other comprehensive income (loss) 5,887 74 5,813 (5,887 ) 5,887 Comprehensive income (loss) $ 266,278 $ 99,815 $ 5,238 $ (105,053 ) $ 266,278 Six months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net (loss) income $ (582,043 ) $ 21 $ (24,449 ) $ 24,428 $ (582,043 ) Foreign currency translation adjustment 8,374 — 9,669 (9,669 ) 8,374 Other comprehensive income (loss) 8,374 — 9,669 (9,669 ) 8,374 Comprehensive (loss) income $ (573,669 ) $ 21 $ (14,780 ) $ 14,759 $ (573,669 )
Condensed Consolidating Statements of Cash Flows	CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Amounts in thousands) Six months ended June 30, 2017 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 268,068 $ 18,585 $ 1 $ (1 ) $ 286,653 Net cash (used in) provided by investing activities (1,669,539 ) (1,362,222 ) (1,151 ) 1,388,288 (1,644,624 ) Net cash provided by (used in) financing activities 199,651 1,387,137 1,150 (1,388,287 ) 199,651 Net (decrease) increase in cash and cash equivalents (1,201,820 ) 43,500 — — (1,158,320 ) Cash and cash equivalents at beginning of period 1,273,882 1,993 — — 1,275,875 Cash and cash equivalents at end of period $ 72,062 $ 45,493 $ — $ — $ 117,555 Six months ended June 30, 2016 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by operating activities $ 142,470 $ 254 $ — $ — $ 142,724 Net cash (used in) provided by investing activities (281,044 ) (25,500 ) (13,690 ) 39,190 (281,044 ) Net cash provided by (used in) financing activities 421,783 25,500 13,690 (39,190 ) 421,783 Net increase in cash and cash equivalents 283,209 254 — — 283,463 Cash and cash equivalents at beginning of period 112,494 479 1 — 112,974 Cash and cash equivalents at end of period $ 395,703 $ 733 $ 1 $ — $ 396,437

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) $ / shares in Units, shares in Millions	Feb. 17, 2017USD ($)a$ / sharesshares	Feb. 16, 2017USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Dec. 15, 2016$ / shares
Business Acquisition [Line Items]
Acquisition expense			$ 1,060,000	$ 0	$ 2,358,000	$ 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 (in shares) | shares	23.9
Acquisition expense			$ 1,100,000		$ 2,400,000
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 (in 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	3 Months Ended		4 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenue	$ 51,069		$ 77,997
Pro forma revenue	323,953	$ (28,012)		$ 692,856	$ 175,700
Pro forma net income (loss)	$ 105,936	$ (461,007)		$ 281,817	$ (735,214)
Pro forma earnings (loss) per share (basic) (in dollars per share)	$ 0.58	$ (3.09)		$ 1.60	$ (5.17)
Pro forma earnings (loss) per share (diluted) (in dollars per share)	$ 0.58	$ (3.09)		$ 1.59	$ (5.17)

Property and Equipment (Schedul

Property and Equipment (Schedule of Property and Equipment) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Oil and natural gas properties	$ 8,500,790	$ 6,071,920
Office furniture and fixtures	30,227	21,204
Building	44,474	42,530
Land	4,820	5,252
Total property and equipment	8,580,311	6,140,906
Accumulated depletion, depreciation, amortization and impairment	(3,937,656)	(3,789,780)
Property and equipment, net	$ 4,642,655	$ 2,351,126

Property and Equipment (Narrati

Property and Equipment (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Impairment of oil and natural gas properties	$ 0	$ 170,621	$ 0	$ 389,612
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool	146,600		146,600
Capitalized general and administrative costs	8,300	$ 7,900	16,700	$ 15,000
Capitalized costs of oil and natural gas properties excluded from amortization	$ 3,109,143		$ 3,109,143		$ 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	Jun. 30, 2017	Dec. 31, 2016
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	$ 3,109,143	$ 1,580,305
Utica
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	1,614,824
MidCon
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	1,491,144
Niobrara
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	2,173
Southern Louisiana
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total oil and gas properties not subject to amortization, total	536
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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation, beginning of period			$ 34,276	$ 26,437
Liabilities incurred			9,505	3,195
Liabilities settled			(344)	(72)
Accretion expense	$ 410	$ 261	692	508
Asset retirement obligation as of end of period	44,129	30,068	44,129	30,068
Less current portion	195	75	195	75	$ 195
Asset retirement obligation, long-term	$ 43,934	$ 29,993	$ 43,934	$ 29,993	$ 34,081

Equity Investments (Investments

Equity Investments (Investments Accounted for by the Equity Method) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Equity investments and investments in subsidiaries	$ 256,265		$ 256,265		$ 243,920
(Income) loss from equity method investments	$ 13,301	$ 836	$ 18,208	$ 31,573
Investment in Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	23.50%		23.50%
Equity investments and investments in subsidiaries	$ 0		$ 0		0
(Income) loss from equity method investments	$ (211)	0	$ (454)	(159)
Investment in Tatex Thailand III, LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	17.90%		17.90%
Equity investments and investments in subsidiaries	$ 0		$ 0		0
(Income) loss from equity method investments	$ 0	0	$ 0	0
Investment in Grizzly Oil Sands ULC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	24.9999%		24.9999%
Equity investments and investments in subsidiaries	$ 51,604		$ 51,604		45,213
(Income) loss from equity method investments	$ 208	763	$ 573	24,448
Investment in Timber Wolf Terminals LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	50.00%		50.00%
Equity investments and investments in subsidiaries	$ 987		$ 987		991
(Income) loss from equity method investments	$ 0	1	$ 4	4
Investment in Windsor Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	22.50%		22.50%
Equity investments and investments in subsidiaries	$ 270		$ 270		25,749
(Income) loss from equity method investments	$ 25,545	(2,881)	$ 25,234	(3,048)
Investment in Stingray Cementing LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	0.00%		0.00%
Equity investments and investments in subsidiaries	$ 0		$ 0		1,920
(Income) loss from equity method investments	$ 77	78	$ 205	108
Investment in Blackhawk Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	48.50%		48.50%
Equity investments and investments in subsidiaries	$ 0		$ 0		0
(Income) loss from equity method investments	$ 0	0	$ 0	0
Investment in Stingray Energy Services LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	0.00%		0.00%
Equity investments and investments in subsidiaries	$ 0		$ 0		4,215
(Income) loss from equity method investments	$ 85	139	$ 282	641
Investment in Sturgeon Acquisitions LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	0.00%		0.00%			25.00%
Equity investments and investments in subsidiaries	$ 0		$ 0		20,526
(Income) loss from equity method investments	$ (139)	134	$ (71)	511
Investment in Mammoth Energy Services, Inc.
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	25.10%		25.10%
Equity investments and investments in subsidiaries	$ 150,458		$ 150,458		111,717
(Income) loss from equity method investments	$ (12,181)	2,543	$ (10,023)	9,009
Investment in Strike Force Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	25.00%		25.00%
Equity investments and investments in subsidiaries	$ 52,946		$ 52,946		$ 33,589
(Income) loss from equity method investments	$ (83)	$ 59	$ 2,458	$ 59

Equity Investments (Equity Inve

Equity Investments (Equity Investments Balance Sheet Disclosure) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Current assets	$ 145,857	$ 148,733
Noncurrent assets	1,414,377	1,305,407
Current liabilities	102,011	57,173
Noncurrent liabilities	$ 137,215	$ 67,680

Equity Investments (Equity In43

Equity Investments (Equity Investment Income Statement Disclosure) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Gross revenue	$ 99,640	$ 86,732	$ 194,118	$ 130,039
Net loss	$ (67,336)	$ (560)	$ (92,675)	$ (25,868)

Equity Investments (Narrative)

Equity Investments (Narrative) (Details) $ / shares in Units, a in Thousands, $ in Thousands	Jun. 05, 2017USD ($)$ / sharesshares	Oct. 31, 2016USD ($)$ / sharesshares	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2014entity	Sep. 30, 2014a	Jun. 30, 2017USD ($)a	Jun. 30, 2016USD ($)	Dec. 31, 2014USD ($)	Feb. 17, 2017$ / shares	Dec. 15, 2016$ / shares	Feb. 29, 2016USD ($)	Mar. 31, 2015
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments and investments in subsidiaries			$ (13,301)	$ (836)				$ (18,208)	$ (31,573)
Distributions from equity method investments								1,429	4,658
Payments for equity method investments								24,151	16,690
Share price (in dollars per share) | $ / shares											$ 19.48	$ 20.96
IPO | Common Stock | Mammoth Energy Services 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
Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments and investments in subsidiaries			$ 211	0				$ 454	159
Equity method investment, ownership interest, percent			23.50%					23.50%
Tatex Thailand III, LLC
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments and investments in subsidiaries			$ 0	0				$ 0	0
Equity method investment, ownership interest, percent			17.90%					17.90%
Grizzly Oil Sands ULC
Schedule of Equity Method Investments [Line Items]
Gas and oil area, reserve (acres) | a								830
Income (loss) from equity method investments and investments in subsidiaries			$ (208)	(763)				$ (573)	(24,448)
Other than temporary impairment loss					$ 23,100
Equity method investment, amount of cash calls, based on proportionate ownership interest								1,200
Equity method investments, increase (decrease) due to foreign currency translation adjustment			$ 4,500	(600)				$ 5,800	9,700
Equity method investment, ownership interest, percent			24.9999%					24.9999%
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]
Income (loss) from equity method investments and investments in subsidiaries			$ (25,545)	2,881				$ (25,234)	3,048
Equity method investment, ownership interest, percent			22.50%					22.50%
Loss from equity method investment, net of related out-of-pocket activity								$ (23,400)
Distributions from equity method investments								200	4,900
Coronado Midstream LLC | Windsor Midstream LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent														28.40%
Sturgeon Acquisitions LLC
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments and investments in subsidiaries			$ 139	(134)				$ 71	(511)
Equity method investment, ownership interest, percent			0.00%			25.00%		0.00%		25.00%
Payments for equity method investments										$ 20,700
Gain on sale of equity method investments	$ 12,500
Mammoth Energy Services LP
Schedule of Equity Method Investments [Line Items]
Equity method investments, increase (decrease) due to foreign currency translation adjustment			$ 20	(100)				$ 100	(1,300)
Equity method investment, ownership interest, percent	25.10%					30.50%				30.50%
Number of entities contributed for ownership interest | entity						4
Shares received from equity method investee in exchange for ownership interest (in shares) | shares	2,000,000	9,150,000
Share price (in dollars per share) | $ / shares	$ 18.50
Mammoth Energy Services LP | IPO | Common Stock | Mammoth Energy Services LP
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 | Certain 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]
Income (loss) from equity method investments and investments in subsidiaries			$ 83	$ (59)				(2,458)	(59)
Equity method investment, amount of cash calls, based on proportionate ownership interest								$ 23,000
Equity method investment, ownership interest, percent			25.00%					25.00%
Distributions from equity method investments								$ 1,200	$ 3,000
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 Llc
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
Apico Llc | Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage			8.50%					8.50%
Strike Force Midstream LLC | Rice Energy Inc
Schedule of Equity Method Investments [Line Items]
Ownership percentage by parent													75.00%

Long-Term Debt (Break-Down of L

Long-Term Debt (Break-Down of Long-Term Debt) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016		Dec. 21, 2016	Oct. 31, 2016	Oct. 14, 2016	Jun. 04, 2015	Apr. 21, 2015
Debt Instrument [Line Items]
Deferred finance costs, net	[1]	$ (30,804)	$ (27,174)
Less: current maturities of long term debt		(595)	(276)
Long-term debt, net of current maturities		1,802,554	$ 1,593,599
Construction loans
Debt Instrument [Line Items]
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	[2]	$ 0	$ 0
6.625% Senior Notes due 2023 | Senior notes
Debt Instrument [Line Items]
Stated interest rate, percent		6.625%	6.625%						6.625%
Long-term debt	[3]	$ 350,000	$ 350,000
Deferred finance costs, net		$ (5,600)
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		$ (10,500)
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	[5]	$ 600,000	$ 600,000
Deferred finance costs, net		(14,600)
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Amended and restated credit agreement
Debt Instrument [Line Items]
Long-term debt	[6]	210,000	0
InterBank | Revolving credit agreement | Construction loans
Debt Instrument [Line Items]
Stated interest rate, percent								4.50%
InterBank | Letter of credit | Construction loans
Debt Instrument [Line Items]
Long-term debt		$ 23,953	$ 21,049	[7]
[1]	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 June 30, 2017, total unamortized debt issuance costs were $5.6 million for the 2023 Notes, $10.5 million for the 2024 Notes and $14.6 million for the 2025 Notes.
[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 accrues at a rate of 6.625% per annum on the outstanding principal amount thereof, payable semi-annually on May 1 and November 1 of each year. 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]	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. 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.As of June 30, 2017, $210.0 million was outstanding under the revolving credit facility and the total availability for future borrowings under this facility, after giving effect to an aggregate of $237.5 million of letters of credit, was $552.5 million. The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. 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 June 30, 2017, amounts borrowed under the credit facility bore interest at the eurodollar rate (3.46%).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 June 30, 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 was 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 June 30, 2017, the total borrowings under the Construction Loan were approximately $24.0 million.

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details)		May 04, 2017bank	Dec. 21, 2016USD ($)	Dec. 13, 2016USD ($)	Dec. 12, 2016	Oct. 14, 2016USD ($)	Jan. 31, 2016	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	May 03, 2017USD ($)	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								$ 3,600,000	$ 1,400,000	$ 6,700,000	$ 3,000,000
Interest capitalized										6,699,000	3,707,000
Deferred finance costs, net	[1]							30,804,000		30,804,000				$ 27,174,000
Construction loans
Debt Instrument [Line Items]
Interest capitalized								0	$ 400,000	0	$ 700,000
Deferred finance costs, net								$ 100,000		$ 100,000
Amended and restated credit agreement | Maximum
Debt Instrument [Line Items]
Debt covenant ratio for future EBITDAX								4		4
Amended and restated credit agreement | Revolving credit agreement
Debt Instrument [Line Items]
Debt covenant ratio for EBITDAX								3		3
7.75% Senior Notes due 2020 | Senior notes
Debt Instrument [Line Items]
Long-term debt	[2]							$ 0		$ 0				$ 0
Stated interest rate, percent								7.75%		7.75%				7.75%
Debt instrument, amount																			$ 600,000,000
Amount validly tendered																$ 600,000,000
6.000% Senior Notes due 2024 | Senior notes
Debt Instrument [Line Items]
Long-term debt	[3]							$ 650,000,000		$ 650,000,000				$ 650,000,000
Stated interest rate, percent						6.00%		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								$ 10,500,000		$ 10,500,000
6.625% Senior Notes due 2023 | Senior notes
Debt Instrument [Line Items]
Long-term debt	[4]							$ 350,000,000		$ 350,000,000				$ 350,000,000
Stated interest rate, percent								6.625%		6.625%				6.625%				6.625%
Debt instrument, amount																		$ 350,000,000
Building loan outstanding amount of building loan refinanced																		$ 343,600,000
Deferred finance costs, net								$ 5,600,000		$ 5,600,000
6.375% Senior Notes due 2025 | Senior notes
Debt Instrument [Line Items]
Long-term debt	[5]							$ 600,000,000		$ 600,000,000				$ 600,000,000
Stated interest rate, percent			6.375%					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								$ 14,600,000		$ 14,600,000
Nova Scotia, Amegy, KeyBank | Amended and restated credit agreement
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis										LIBOR01
Nova Scotia, Amegy, KeyBank | Revolving credit agreement
Debt Instrument [Line Items]
Weighted average interest rate										3.46%
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Base rate | Minimum
Debt Instrument [Line Items]
Stated interest rate, percent								1.00%		1.00%
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Base rate | Maximum
Debt Instrument [Line Items]
Stated interest rate, percent								2.00%		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%		2.00%
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Eurodollar | Maximum
Debt Instrument [Line Items]
Stated interest rate, percent								3.00%		3.00%
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Amended and restated credit agreement
Debt Instrument [Line Items]
Maximum borrowing capacity								$ 1,500,000,000		$ 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
Borrowing base								1,000,000,000		1,000,000,000		$ 700,000,000
Number of banks added to syndicate | bank		5
Long-term debt	[6]							210,000,000		210,000,000				$ 0
Remaining borrowing capacity	[6]							552,500,000		552,500,000
Nova Scotia, Amegy, KeyBank | Unsecured debt | Amended and restated credit agreement
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 1,600,000,000
Nova Scotia, Amegy, KeyBank | Unsecured debt | Amended and restated credit agreement | Revolving credit agreement
Debt Instrument [Line Items]
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								237,500,000		237,500,000
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]
Maximum borrowing capacity																	$ 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								$ 23,953,000		$ 23,953,000				$ 21,049,000	[7]
[1]	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 June 30, 2017, total unamortized debt issuance costs were $5.6 million for the 2023 Notes, $10.5 million for the 2024 Notes and $14.6 million for the 2025 Notes.
[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 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]	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 accrues at a rate of 6.625% per annum on the outstanding principal amount thereof, payable semi-annually on May 1 and November 1 of each year. The 2023 Notes are not guaranteed by Grizzly Holdings, Inc. and will not be guaranteed by any of the Company’s future unrestricted subsidiaries.
[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]	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. 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.As of June 30, 2017, $210.0 million was outstanding under the revolving credit facility and the total availability for future borrowings under this facility, after giving effect to an aggregate of $237.5 million of letters of credit, was $552.5 million. The Company’s wholly-owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. 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 June 30, 2017, amounts borrowed under the credit facility bore interest at the eurodollar rate (3.46%).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 June 30, 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 was 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 June 30, 2017, the total borrowings under the Construction Loan were approximately $24.0 million.

Common Stock and Changes in C47

Common Stock and Changes in Capitalization (Narrative) (Details) - USD ($) $ in Thousands	Feb. 17, 2017	Mar. 15, 2016	Jun. 30, 2017	Jun. 30, 2016
Class of Stock [Line Items]
Proceeds from issuance of common stock, net of offering costs		$ 411,700	$ (5,364)	$ 411,711
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 (in shares)	23,900,000
Vitruvian acquisition | Indemnity escrow
Class of Stock [Line Items]
Equity interest issued or issuable, number of shares (in 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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation [Abstract]
Stock-based compensation expense	$ 2.6	$ 3.3	$ 5.2	$ 6.6
Capitalized stock-based compensation	1.1	$ 1.3	2.1	$ 2.6
Unrecognized compensation expense	$ 16.1		$ 16.1
Weighted average period of expense recognition period			1 year 7 months 2 days

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary of Restricted Stock Award and Unit Activity) (Details) - Restricted Stock	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Number of Unvested Restricted Shares
Unvested shares as of January 1, 2017 | shares	613,056
Granted (in shares) | shares	525,808
Vested (in shares) | shares	(172,988)
Forfeited (in shares) | shares	(66,661)
Unvested shares as of June 30, 2017 | shares	899,215
Weighted Average Grant Date Fair Value
Unvested shares as of January 1, 2017 | $ / shares	$ 32.90
Granted (in dollars per share) | $ / shares	17.31
Vested (in dollars per share) | $ / shares	32.06
Forfeited (in dollars per share) | $ / shares	31.18
Unvested shares as of June 30, 2017 | $ / shares	$ 24.08

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Earnings Per Share Reconciliation) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Basic:
Net loss (loss) - basic	$ 105,936	$ (339,776)	$ 260,391	$ (582,043)
Net income (loss) (in shares)	182,840,213	125,343,723	176,591,166	118,426,654
Net income (loss) - basic (in dollars per share)	$ 0.58	$ (2.71)	$ 1.47	$ (4.91)
Effect of dilutive securities:
Stock options and awards	$ 0	$ 0	$ 0	$ 0
Stock options and awards (in shares)	1,517	0	251,073	0
Diluted:
Net income (loss) - diluted	$ 105,936	$ (339,776)	$ 260,391	$ (582,043)
Net income (loss) (in share)	182,841,730	125,343,723	176,842,239	118,426,654
Net income (loss) - diluted (in dollars per share)	$ 0.58	$ (2.71)	$ 1.47	$ (4.91)
Common stock considered anti-dilutive (in shares)		573,187		558,894

Commitments and Contingencies51

Commitments and Contingencies (Narrative) (Details) $ in Thousands	Jul. 29, 2016defendant	Feb. 09, 2016defendant	Mar. 11, 1997	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)well	Jul. 29, 2016claim	Jun. 30, 2016USD ($)	Dec. 31, 1997USD ($)well
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 year to date				$ 700	$ 0		$ 2,000
Minimum
Commitments [Line Items]
Operating lease, term					1 year

Commitments and Contingencies52

Commitments and Contingencies (Operating Leases Future Minimum Lease Commitments) (Details) $ in Thousands	Jun. 30, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining 2,017	$ 70
2,018	54
Total	$ 124

Commitments and Contingencies53

Commitments and Contingencies (Firm Transportation Commitments) (Details) $ in Thousands	Jun. 30, 2017USD ($)MMBTU / d
Other Commitments [Line Items]
Firm sale contracts (in MMBtu's) | MMBTU / d	2,930,000
Long-term Commitment (Excluding Unconditional Purchase Obligation) [Abstract]
Remaining 2017 | MMBTU / d	728,000
2018 | MMBTU / d	498,000
2019 | MMBTU / d	579,000
2020 | MMBTU / d	506,000
2021 | MMBTU / d	371,000
Thereafter | MMBTU / d	248,000
Total | MMBTU / d	2,930,000
Purchase commitment
Other Commitments [Abstract]
2,018	$ 39,330
Total	65,550
Transportation commitment
Other Commitments [Abstract]
Remaining 2,017	105,871
2,018	246,749
2,019	243,389
2,020	240,746
2,021	239,786
Thereafter	2,705,270
Total	$ 3,781,811

Commitments and Contingencies54

Commitments and Contingencies (Other Commitments) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Purchase commitment
Other Commitments [Line Items]
Remaining 2,017		$ 26,220
2,018		39,330
Total		65,550
Loss on long-term purchase commitment | Muskie Proppant LLC
Other Commitments [Line Items]
Long-term purchase commitment, accrued damages year to date	$ 700	$ 0	$ 2,000

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2017MMBTU$ / MMBTU	Jun. 30, 2017$ / MMBTU
Derivative [Line Items]
Derivative, extension option term		12 months
2,018
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	30,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.36	3.36
2018 | Short
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	30,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.36	3.36

Derivative Instruments (Schedul

Derivative Instruments (Schedule of Derivative Instruments) (Details)	3 Months Ended
	Jun. 30, 2017bbl / dMMBTU$ / MMBTU$ / bbl
Remaining 2017 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	681,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.20
Remaining 2017 | ARGUS LLS
Derivative [Line Items]
Daily Volume (in Bbls) | bbl / d	2,000
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl	53.12
Remaining 2017 | NYMEX WTI
Derivative [Line Items]
Daily Volume (in Bbls) | bbl / d	5,000
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl	54.89
Remaining 2017 | Mont Belvieu C3
Derivative [Line Items]
Daily Volume (in Bbls) | bbl / d	3,000
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl	26.63
Remaining 2017 | Mont Belvieu C5
Derivative [Line Items]
Daily Volume (in Bbls) | bbl / d	250
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl	49.14
2,018
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	30,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.36
2018 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	669,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.08
2018 | NYMEX WTI
Derivative [Line Items]
Daily Volume (in Bbls) | bbl / d	1,000
Weighted average price (in usd per MMBtu or Bbls) | $ / bbl	55.31
2019 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	57,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.10
Short | 2018
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	30,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.36
Short | Call Option | Remaining 2017 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	65,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.11
Short | Call Option | Remaining 2017 | NYMEX Henry Hub to NPG Mid-Continent
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	50,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	0.26
Short | Call Option | 2018 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	103,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.25
Short | Call Option | 2018 | NYMEX Henry Hub to NPG Mid-Continent
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	12,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	0.26
Short | Call Option | 2019 | NYMEX Henry Hub
Derivative [Line Items]
Daily Volume (in MMBtu) | MMBTU	35,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.11

Derivative Instruments (Sched57

Derivative Instruments (Schedule of Derivative Instruments in Statement of Financial Position) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Short-term derivative instruments - asset	$ 46,416	$ 3,488
Long-term derivative instruments - asset	19,761	5,696
Short-term derivative instruments - liability	28,106	119,219
Long-term derivative instruments - liability	$ 8,198	$ 26,759

Derivative Instruments (Net Gai

Derivative Instruments (Net Gain (Loss) on Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative [Line Items]
Net gain (loss) on natural gas, oil, and NGL derivatives	$ 64,871	$ (137,392)	$ 164,448	$ (79,657)
Natural gas derivatives
Derivative [Line Items]
Net gain (loss) on natural gas, oil, and NGL derivatives	56,668	(133,621)	142,945	(76,621)
Oil derivatives
Derivative [Line Items]
Net gain (loss) on natural gas, oil, and NGL derivatives	8,143	(2,628)	19,048	(1,346)
Natural gas liquids derivatives
Derivative [Line Items]
Net gain (loss) on natural gas, oil, and NGL derivatives	$ 60	$ (1,143)	$ 2,455	$ (1,690)

Derivative Instruments (Sched59

Derivative Instruments (Schedule of Offsetting) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross Assets Presented in the Consolidated Balance Sheet	$ 66,177	$ 9,184
Gross Assets Subject to Mater Netting Agreement - assets	(27,984)	(9,184)
Net Amount - assets	38,193	0
Gross Liabilities Presented in the Consolidated Balance Sheet	(36,304)	(145,978)
Gross Amounts Subject to Master Netting Agreement - liabilities	27,984	9,184
Net Amount - liabilities	$ (8,320)	$ (136,794)

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Derivative Instruments) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Mar. 31, 2016	Feb. 29, 2016
Liabilities:
Asset retirement obligation capitalized	$ 9,505	$ 3,195
Level 1
Assets:
Derivative Instruments	0		$ 0
Liabilities:
Derivative Instruments	0		0
Level 2
Assets:
Derivative Instruments	66,177		9,184
Liabilities:
Derivative Instruments	36,304		145,978
Level 3
Assets:
Derivative Instruments	0		0
Liabilities:
Derivative Instruments	0		$ 0
Asset retirement obligation capitalized	$ 9,500
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		Jun. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Deferred finance costs, net	[1]	$ 30,804	$ 27,174
Senior notes | 6.625% Senior Notes due 2023
Debt Instrument [Line Items]
Deferred finance costs, net		5,600
Senior notes | 6.000% Senior Notes due 2024
Debt Instrument [Line Items]
Deferred finance costs, net		10,500
Senior notes | 6.375% Senior Notes due 2025
Debt Instrument [Line Items]
Deferred finance costs, net		14,600
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
[1]	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 June 30, 2017, total unamortized debt issuance costs were $5.6 million for the 2023 Notes, $10.5 million for the 2024 Notes and $14.6 million for the 2025 Notes.

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	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 117,555	$ 1,275,875	$ 396,437	$ 112,974
Restricted Cash	0	185,000
Accounts receivable—oil and natural gas	164,154	136,761
Accounts receivable - related parties	185	16
Accounts receivable - intercompany		0
Prepaid expenses and other current assets	4,279	3,135
Short-term derivative instruments	46,416	3,488
Total current assets	332,589	1,604,275
Property and equipment:
Oil and natural gas properties	8,500,790	6,071,920
Other property and equipment	79,521	68,986
Accumulated depletion, depreciation, amortization and impairment	(3,937,656)	(3,789,780)
Property and equipment, net	4,642,655	2,351,126
Other assets:
Equity investments and investments in subsidiaries	256,265	243,920
Long-term derivative instruments	19,761	5,696
Deferred tax asset	4,692	4,692
Inventories	19,303	4,504
Other assets	18,890	8,932
Total other assets	318,911	267,744
Total assets	5,294,155	4,223,145
Current liabilities:
Accounts payable and accrued liabilities	495,734	265,124
Accounts payable - intercompany	0	0
Asset retirement obligation—current	195	195	75
Derivative instruments	28,106	119,219
Current maturities of long-term debt	595	276
Total current liabilities	524,630	384,814
Long-term derivative instrument	8,198	26,759
Asset retirement obligation—long-term	43,934	34,081	29,993
Long-term debt, net of current maturities	1,802,554	1,593,599
Total liabilities	2,379,316	2,039,253
Stockholders’ equity:
Common stock	1,828	1,588
Paid-in capital	4,410,871	3,946,442
Accumulated other comprehensive (loss) income	(47,171)	(53,058)
Retained (deficit) earnings	(1,450,689)	(1,711,080)
Total stockholders’ equity	2,914,839	2,183,892	1,883,440	2,038,837
Total liabilities and stockholders’ equity	5,294,155	4,223,145
Reportable Legal Entities | Parent
Current assets:
Cash and cash equivalents	72,062	1,273,882	395,703	112,494
Restricted Cash		185,000
Accounts receivable—oil and natural gas	121,565	137,087
Accounts receivable - related parties	185	16
Accounts receivable - intercompany	459,503	449,517
Prepaid expenses and other current assets	4,113	3,135
Short-term derivative instruments	46,416	3,488
Total current assets	703,844	2,052,125
Property and equipment:
Oil and natural gas properties	6,142,757	5,655,125
Other property and equipment	79,478	68,943
Accumulated depletion, depreciation, amortization and impairment	(3,937,621)	(3,789,746)
Property and equipment, net	2,284,614	1,934,322
Other assets:
Equity investments and investments in subsidiaries	2,179,931	236,327
Long-term derivative instruments	19,761	5,696
Deferred tax asset	4,692	4,692
Inventories	13,591	3,095
Other assets	10,834	8,932
Total other assets	2,228,809	258,742
Total assets	5,217,267	4,245,189
Current liabilities:
Accounts payable and accrued liabilities	385,908	255,966
Accounts payable - intercompany	39,564	31,202
Asset retirement obligation—current	195	195
Derivative instruments	28,106	119,219
Current maturities of long-term debt	595	276
Total current liabilities	454,368	406,858
Long-term derivative instrument	8,198	26,759
Asset retirement obligation—long-term	37,308	34,081
Long-term debt, net of current maturities	1,802,554	1,593,599
Total liabilities	2,302,428	2,061,297
Stockholders’ equity:
Common stock	1,828	1,588
Paid-in capital	4,410,871	3,946,442
Accumulated other comprehensive (loss) income	(47,171)	(53,058)
Retained (deficit) earnings	(1,450,689)	(1,711,080)
Total stockholders’ equity	2,914,839	2,183,892
Total liabilities and stockholders’ equity	5,217,267	4,245,189
Reportable Legal Entities | Guarantors
Current assets:
Cash and cash equivalents	45,493	1,993	733	479
Restricted Cash		0
Accounts receivable—oil and natural gas	42,589	37,496
Accounts receivable - related parties	0	0
Accounts receivable - intercompany	45,749	1,151
Prepaid expenses and other current assets	166	0
Short-term derivative instruments	0	0
Total current assets	133,997	40,640
Property and equipment:
Oil and natural gas properties	2,358,762	417,524
Other property and equipment	43	43
Accumulated depletion, depreciation, amortization and impairment	(35)	(34)
Property and equipment, net	2,358,770	417,533
Other assets:
Equity investments and investments in subsidiaries	52,946	33,590
Long-term derivative instruments	0	0
Deferred tax asset	0	0
Inventories	5,712	1,409
Other assets	8,056	0
Total other assets	66,714	34,999
Total assets	2,559,481	493,172
Current liabilities:
Accounts payable and accrued liabilities	109,826	9,158
Accounts payable - intercompany	465,561	457,163
Asset retirement obligation—current	0	0
Derivative instruments	0	0
Current maturities of long-term debt	0	0
Total current liabilities	575,387	466,321
Long-term derivative instrument	0	0
Asset retirement obligation—long-term	6,626	0
Long-term debt, net of current maturities	0	0
Total liabilities	582,013	466,321
Stockholders’ equity:
Common stock	0	0
Paid-in capital	1,885,598	33,822
Accumulated other comprehensive (loss) income	0	0
Retained (deficit) earnings	91,870	(6,971)
Total stockholders’ equity	1,977,468	26,851
Total liabilities and stockholders’ equity	2,559,481	493,172
Reportable Legal Entities | Non-Guarantor
Current assets:
Cash and cash equivalents	0	0	1	1
Restricted Cash		0
Accounts receivable—oil and natural 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	0	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	51,605	45,213
Long-term derivative instruments	0	0
Deferred tax asset	0	0
Inventories	0	0
Other assets	0	0
Total other assets	51,605	45,213
Total assets	51,605	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	258,178	257,026
Accumulated other comprehensive (loss) income	(45,117)	(50,931)
Retained (deficit) earnings	(161,583)	(161,008)
Total stockholders’ equity	51,478	45,087
Total liabilities and stockholders’ equity	51,605	45,213
Eliminations
Current assets:
Cash and cash equivalents	0	0	$ 0	$ 0
Restricted Cash		0
Accounts receivable—oil and natural gas	0	(37,822)
Accounts receivable - related parties	0	0
Accounts receivable - intercompany	(505,252)	(450,668)
Prepaid expenses and other current assets	0	0
Short-term derivative instruments	0	0
Total current assets	(505,252)	(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	(2,028,217)	(71,210)
Long-term derivative instruments	0	0
Deferred tax asset	0	0
Inventories	0	0
Other assets	0	0
Total other assets	(2,028,217)	(71,210)
Total assets	(2,534,198)	(560,429)
Current liabilities:
Accounts payable and accrued liabilities	0	0
Accounts payable - intercompany	(505,252)	(488,491)
Asset retirement obligation—current	0	0
Derivative instruments	0	0
Current maturities of long-term debt	0	0
Total current liabilities	(505,252)	(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	(505,252)	(488,491)
Stockholders’ equity:
Common stock	0	0
Paid-in capital	(2,143,776)	(290,848)
Accumulated other comprehensive (loss) income	45,117	50,931
Retained (deficit) earnings	69,713	167,979
Total stockholders’ equity	(2,028,946)	(71,938)
Total liabilities and stockholders’ equity	$ (2,534,198)	$ (560,429)

Condensed Consolidating Finan64

Condensed Consolidating Financial Information (Condensed Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Total revenues	$ 323,953	$ (28,159)	$ 656,957	$ 128,802
Costs and expenses:
Lease operating expenses	20,721	14,661	40,024	31,318
Production taxes	5,139	2,856	9,045	5,967
Midstream gathering and processing	58,945	39,349	106,886	77,001
Depreciation, depletion and amortization	82,246	55,652	148,237	121,129
Impairment of oil and natural gas properties	0	170,621	0	389,612
General and administrative	12,257	11,854	24,857	22,474
Accretion expense	410	261	692	508
Acquisition expense	1,060	0	2,358	0
Total costs and expenses	180,778	295,254	332,099	648,009
INCOME (LOSS) FROM OPERATIONS	143,175	(323,413)	324,858	(519,207)
OTHER (INCOME) EXPENSE:
Interest expense	24,188	16,082	47,667	32,105
Interest income	(48)	(391)	(890)	(485)
(Income) loss from equity method investments and investments in subsidiaries	13,301	836	18,208	31,573
Other income	(202)	(7)	(518)	(9)
Total other (income) expense	37,239	16,520	64,467	63,184
INCOME (LOSS) BEFORE INCOME TAXES	105,936	(339,933)	260,391	(582,391)
INCOME TAX EXPENSE	0	(157)	0	(348)
NET INCOME (LOSS)	105,936	(339,776)	260,391	(582,043)
Reportable Legal Entities | Parent
Revenues:
Total revenues	249,353	(28,580)	521,794	128,171
Costs and expenses:
Lease operating expenses	16,423	14,491	33,872	30,963
Production taxes	3,645	2,828	6,747	5,915
Midstream gathering and processing	42,291	39,242	80,015	76,865
Depreciation, depletion and amortization	82,245	55,651	148,235	121,127
Impairment of oil and natural gas properties		170,621		389,612
General and administrative	13,052	11,846	25,926	22,458
Accretion expense	291	261	573	508
Acquisition expense	5		5
Total costs and expenses	157,952	294,940	295,373	647,448
INCOME (LOSS) FROM OPERATIONS	91,401	(323,520)	226,421	(519,277)
OTHER (INCOME) EXPENSE:
Interest expense	26,133	16,082	51,181	32,104
Interest income	(42)	(391)	(884)	(485)
(Income) loss from equity method investments and investments in subsidiaries	(40,475)	722	(83,089)	31,495
Other income	(151)	0	(1,178)	0
Total other (income) expense	(14,535)	16,413	(33,970)	63,114
INCOME (LOSS) BEFORE INCOME TAXES	105,936	(339,933)	260,391	(582,391)
INCOME TAX EXPENSE	0	(157)	0	(348)
NET INCOME (LOSS)	105,936	(339,776)	260,391	(582,043)
Reportable Legal Entities | Guarantors
Revenues:
Total revenues	74,600	421	135,163	631
Costs and expenses:
Lease operating expenses	4,298	170	6,152	355
Production taxes	1,494	28	2,298	52
Midstream gathering and processing	16,654	107	26,871	136
Depreciation, depletion and amortization	1	1	2	2
Impairment of oil and natural gas properties		0		0
General and administrative	(796)	8	(1,071)	14
Accretion expense	119	0	119	0
Acquisition expense	1,055		2,353
Total costs and expenses	22,825	314	36,724	559
INCOME (LOSS) FROM OPERATIONS	51,775	107	98,439	72
OTHER (INCOME) EXPENSE:
Interest expense	(1,945)	0	(3,514)	1
Interest income	(6)	0	(6)	0
(Income) loss from equity method investments and investments in subsidiaries	(83)	59	2,458	59
Other income	(51)	(7)	(240)	(9)
Total other (income) expense	(2,085)	52	(1,302)	51
INCOME (LOSS) BEFORE INCOME TAXES	53,860	55	99,741	21
INCOME TAX EXPENSE	0	0	0	0
NET INCOME (LOSS)	53,860	55	99,741	21
Reportable Legal Entities | Non-Guarantor
Revenues:
Total revenues	0	0	0	0
Costs and expenses:
Lease operating expenses	0	0	0	0
Production taxes	0	0	0	0
Midstream gathering and processing	0	0	0	0
Depreciation, depletion and amortization	0	0	0
Impairment of oil and natural gas properties		0		0
General and administrative	1	0	2	2
Accretion expense	0	0	0	0
Acquisition expense	0		0
Total costs and expenses	1	0	2	2
INCOME (LOSS) FROM OPERATIONS	(1)	0	(2)	(2)
OTHER (INCOME) EXPENSE:
Interest expense	0	0	0	0
Interest income	0	0	0	0
(Income) loss from equity method investments and investments in subsidiaries	208	762	573	24,447
Other income	0	0	0	0
Total other (income) expense	208	762	573	24,447
INCOME (LOSS) BEFORE INCOME TAXES	(209)	(762)	(575)	(24,449)
INCOME TAX EXPENSE	0	0	0	0
NET INCOME (LOSS)	(209)	(762)	(575)	(24,449)
Eliminations
Revenues:
Total revenues	0	0	0	0
Costs and expenses:
Lease operating expenses	0	0	0	0
Production taxes	0	0	0	0
Midstream gathering and processing	0	0	0	0
Depreciation, depletion and amortization	0	0	0
Impairment of oil and natural gas properties		0		0
General and administrative	0	0	0	0
Accretion expense	0	0	0	0
Acquisition expense	0		0
Total costs and expenses	0	0	0	0
INCOME (LOSS) FROM OPERATIONS	0	0	0	0
OTHER (INCOME) EXPENSE:
Interest expense	0	0	0	0
Interest income	0	0	0	0
(Income) loss from equity method investments and investments in subsidiaries	53,651	(707)	98,266	(24,428)
Other income	0	0	900	0
Total other (income) expense	53,651	(707)	99,166	(24,428)
INCOME (LOSS) BEFORE INCOME TAXES	(53,651)	707	(99,166)	24,428
INCOME TAX EXPENSE	0	0	0	0
NET INCOME (LOSS)	$ (53,651)	$ 707	$ (99,166)	$ 24,428

Condensed Consolidating Finan65

Condensed Consolidating Financial Information (Condensed Consolidating Statements of Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ 105,936	$ (339,776)	$ 260,391	$ (582,043)
Foreign currency translation adjustment	4,514	(684)	5,887	8,374
Other comprehensive income (loss)	4,514	(684)	5,887	8,374
Comprehensive income (loss)	110,450	(340,460)	266,278	(573,669)
Reportable Legal Entities | Parent
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	105,936	(339,776)	260,391	(582,043)
Foreign currency translation adjustment	4,514	(684)	5,887	8,374
Other comprehensive income (loss)	4,514	(684)	5,887	8,374
Comprehensive income (loss)	110,450	(340,460)	266,278	(573,669)
Reportable Legal Entities | Guarantors
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	53,860	55	99,741	21
Foreign currency translation adjustment	19	0	74	0
Other comprehensive income (loss)	19	0	74	0
Comprehensive income (loss)	53,879	55	99,815	21
Reportable Legal Entities | Non-Guarantor
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(209)	(762)	(575)	(24,449)
Foreign currency translation adjustment	4,495	(604)	5,813	9,669
Other comprehensive income (loss)	4,495	(604)	5,813	9,669
Comprehensive income (loss)	4,286	(1,366)	5,238	(14,780)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(53,651)	707	(99,166)	24,428
Foreign currency translation adjustment	(4,514)	604	(5,887)	(9,669)
Other comprehensive income (loss)	(4,514)	604	(5,887)	(9,669)
Comprehensive income (loss)	$ (58,165)	$ 1,311	$ (105,053)	$ 14,759

Condensed Consolidating Finan66

Condensed Consolidating Financial Information (Condensed Consolidating Statements of Cash Flows (Details)) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 286,653	$ 142,724
Net cash (used in) provided by investing activities	(1,644,624)	(281,044)
Net cash provided by (used in) financing activities	199,651	421,783
Net (decrease) increase in cash and cash equivalents	(1,158,320)	283,463
Cash and cash equivalents at beginning of period	1,275,875	112,974
Cash and cash equivalents at end of period	117,555	396,437
Reportable Legal Entities | Parent
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	268,068	142,470
Net cash (used in) provided by investing activities	(1,669,539)	(281,044)
Net cash provided by (used in) financing activities	199,651	421,783
Net (decrease) increase in cash and cash equivalents	(1,201,820)	283,209
Cash and cash equivalents at beginning of period	1,273,882	112,494
Cash and cash equivalents at end of period	72,062	395,703
Reportable Legal Entities | Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	18,585	254
Net cash (used in) provided by investing activities	(1,362,222)	(25,500)
Net cash provided by (used in) financing activities	1,387,137	25,500
Net (decrease) increase in cash and cash equivalents	43,500	254
Cash and cash equivalents at beginning of period	1,993	479
Cash and cash equivalents at end of period	45,493	733
Reportable Legal Entities | Non-Guarantor
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	1	0
Net cash (used in) provided by investing activities	(1,151)	(13,690)
Net cash provided by (used in) financing activities	1,150	13,690
Net (decrease) increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	1
Cash and cash equivalents at end of period	0	1
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(1)	0
Net cash (used in) provided by investing activities	1,388,288	39,190
Net cash provided by (used in) financing activities	(1,388,287)	(39,190)
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)	1 Months Ended	3 Months Ended
	Aug. 09, 2017MMBTU$ / MMBTU	Jun. 30, 2017MMBTU$ / MMBTU
2,018
Subsequent Event [Line Items]
Daily Volume (in MMBtu) | MMBTU		30,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU		3.36
NYMEX Henry Hub | 2017
Subsequent Event [Line Items]
Daily Volume (in MMBtu) | MMBTU		681,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU		3.20
NYMEX Henry Hub | 2018
Subsequent Event [Line Items]
Daily Volume (in MMBtu) | MMBTU		669,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU		3.08
NYMEX Henry Hub | 2019
Subsequent Event [Line Items]
Daily Volume (in MMBtu) | MMBTU		57,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU		3.10
Subsequent event | NYMEX Henry Hub | 2017
Subsequent Event [Line Items]
Daily Volume (in MMBtu) | MMBTU	66,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.08
Subsequent event | NYMEX Henry Hub | 2018
Subsequent Event [Line Items]
Daily Volume (in MMBtu) | MMBTU	105,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	2.94
Subsequent event | NYMEX Henry Hub | 2019
Subsequent Event [Line Items]
Daily Volume (in MMBtu) | MMBTU	50,000
Weighted average price (in usd per MMBtu or Bbls) | $ / MMBTU	3.04