Gulfport Energy (GPOR) 10-Q/A 27 Feb 20 2019 Q3 Quarterly report (amended) Financial data

COVER PAGE

COVER PAGE - shares	9 Months Ended
	Sep. 30, 2019	Oct. 25, 2019
Cover page.
Document Type	10-Q/A
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	000-19514
Entity Registrant Name	Gulfport Energy Corp
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	73-1521290
Entity Address, Address Line One	3001 Quail Springs Parkway
Entity Address, City or Town	Oklahoma City,
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	73134
City Area Code	405
Local Phone Number	252-4600
Title of 12(b) Security	Common stock, par value $0.01 per share
Trading Symbol	GPOR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		159,709,221
Entity Central Index Key	0000874499
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	true
Amendment Description	This Amendment No. 1 to the Quarterly Report on Form 10-Q/A (the “Amendment”) is being filed by Gulfport Energy Corporation (the "Company") to amend the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2019, which was originally filed with the Securities and Exchange Commission (the "SEC") on November 1, 2019 (the “Original Filing”). The Amendment sets forth the information in Original Filing in its entirety, as adjusted for the effects of the restatement described below.On February 25, 2020, the Audit Committee of the Company's Board of Directors, in conjunction with senior management, concluded that the Company's unaudited consolidated financial statements as of and for the periods ended September 30, 2019 included in the Company's quarterly report on Form 10-Q for the quarterly period ended September 30, 2019 should be restated to correct the error discussed below and should no longer be relied upon.In the course of preparing the consolidated financial statements for the year ended December 31, 2019, the Company identified a misstatement of its depreciation, depletion and amortization and impairment of oil and gas properties as of September 30, 2019 of approximately $554 million ($436 million net of the tax benefit) related to unrecorded transfers of its unevaluated oil and natural gas properties into the amortization base. This error impacted the related calculations of the Company's depreciation, depletion and amortization and impairment of oil and natural gas properties for the three and nine month periods ended September 2019. Net (loss) income and income tax benefit have also been impacted. This Amendment is being filed solely to (i) restate the consolidated financial statements for the misstatement described above to the consolidated financial statements (and to make corresponding changes to the Risk Factors and Management's Discussion and Analysis of Financial Condition and Results of Operations sections in this Amendment) and (ii) amend Item 4 (Controls and Procedures).The following sections in the Original Filing are revised in this Amendment to reflect the restatement:•Part I - Item 1. Consolidated Financial Statements•Part I - Item 2. Management's Discussion and Analysis of Financial Conditions and Results of Operations•Part I - Item 4. Controls and Procedures•Part II - Item 1A. Risk Factors•Part II - Item 6. ExhibitsOur consolidated financial statements as of September 30, 2019 and for the three and nine month periods then ended have been restated to correctly reflect the unproved oil and natural gas properties excluded from amortization and accumulated depletion, depreciation, amortization and impairment in the consolidated balance sheet and the depreciation, depletion and amortization, impairment of oil and natural gas properties, income tax benefit and net loss in the consolidated statements of operations and consolidated statements of cash flows and other related effects on the consolidated financial statements and related footnotes. See restated Note 1 for the adjustments to the consolidated financial statements related to this misstatement. The Company has also made corresponding amendments to Management's Discussion and Analysis of Financial Conditions and Results of Operations. This Amendment resulted from a material weakness in internal control over financial reporting. As such, Item 4 of Part I has been amended for our assessment of the effectiveness of our disclosure controls and procedures pursuant to Rule 13a-15(b) under the Exchange Act. This Amendment includes new certifications from the Company’s Chief Executive Officer and President and Chief Financial Officer dated as of the date of filing of this Amendment, as required by Sections 302 and 906 of the Sarbanes-Oxley act of 2002. The certifications are included in this Amendment as Exhibits 31.1, 31.2, 32.1 and 32.2.This Amendment does not reflect events occurring after the filing of the Original Filing, or modify or update those disclosures affected by subsequent events, except for the effects of the restatement. Disclosures not affected by the restatement are unchanged and reflect the disclosures made at the time of the Original Filing. Accordingly, this Amended Form 10-Q should be read in conjunction with our filings with the SEC subsequent to the date on which we filed the Original Filing with the SEC.

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 10,124	$ 52,297
Accounts receivable—oil and natural gas sales	112,657	210,200
Accounts receivable—joint interest and other	41,327	22,497
Prepaid expenses and other current assets	5,658	10,017
Short-term derivative instruments	134,571	21,352
Total current assets	304,337	316,363
Property and equipment:
Oil and natural gas properties, full-cost accounting, $2,260,759 and $2,873,037 excluded from amortization in 2019 and 2018, respectively	10,551,713	10,026,836
Other property and equipment	96,233	92,667
Accumulated depletion, depreciation, amortization and impairment	(5,616,988)	(4,640,098)
Property and equipment, net	5,030,958	5,479,405
Other assets:
Equity investments	73,962	236,121
Long-term derivative instruments	23,419	0
Deferred tax asset	323,378	0
Inventories	7,022	5,344
Operating lease assets	13,920
Operating lease assets - related parties	48,449
Other assets	11,653	13,803
Total other assets	501,803	255,268
Total assets	5,837,098	6,051,036
Current liabilities:
Accounts payable and accrued liabilities	439,019	518,380
Short-term derivative instruments	429	20,401
Current portion of operating lease liabilities	12,848
Current portion of operating lease liabilities - related parties	21,017
Current maturities of long-term debt	622	651
Total current liabilities	473,935	539,432
Long-term derivative instruments	72,040	13,992
Asset retirement obligation—long-term	59,819	79,952
Uncertain tax position liability	3,127	3,127
Non-current operating lease liabilities	1,072
Non-current operating lease liabilities - related parties	27,432
Long-term debt, net of current maturities	2,076,569	2,086,765
Total liabilities	2,713,994	2,723,268
Commitments and contingencies (Note 8)
Preferred stock, $0.01 par value; 5,000,000 shares authorized (30,000 authorized as redeemable 12% cumulative preferred stock, Series A), and none issued and outstanding	0	0
Stockholders’ equity:
Common stock - $0.01 par value, 200,000,000 shares authorized, 159,709,221 issued and outstanding at September 30, 2019 and 162,986,045 at December 31, 2018	1,597	1,630
Paid-in capital	4,205,158	4,227,532
Accumulated other comprehensive loss	(50,679)	(56,026)
Accumulated deficit	(1,032,972)	(845,368)
Total stockholders’ equity	3,123,104	3,327,768
Total liabilities and stockholders’ equity	$ 5,837,098	$ 6,051,036

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (UNAUDITED) (PARENTHETICAL) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Capitalized costs of oil and natural gas properties excluded from amortization	$ 2,260,759	$ 2,873,037
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, dividend rate	12.00%	12.00%
Preferred stock, shares authorized (in shares)	30,000	30,000
Preferred stock Series A, issued (in shares)	0	0
Preferred stock Series A, outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares, issued (in shares)	159,709,221	162,986,045
Common stock, shares, outstanding (in shares)	159,709,221	162,986,045

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Net gain (loss) on natural gas, oil and NGLs derivatives	$ 27,074,000	$ (9,663,000)	$ 178,169,000	$ (96,737,000)
Total revenues	285,175,000	360,962,000	1,064,747,000	939,094,000
Costs and expenses:
Lease operating expenses	22,473,000	22,325,000	64,668,000	64,143,000
Production taxes	6,565,000	9,348,000	22,584,000	23,861,000
Midstream gathering and processing expenses	78,435,000	78,913,000	220,732,000	214,546,000
Depreciation, depletion and amortization	163,270,000	119,915,000	406,654,000	352,848,000
Impairment of oil and natural gas properties	571,442,000	0	571,442,000	0
General and administrative expenses	14,659,000	15,848,000	39,482,000	42,955,000
Accretion expense	747,000	1,037,000	3,173,000	3,056,000
Total costs and expenses	857,591,000	247,386,000	1,328,735,000	701,409,000
(LOSS) INCOME FROM OPERATIONS	(572,416,000)	113,576,000	(263,988,000)	237,685,000
OTHER EXPENSE (INCOME):
Interest expense	34,095,000	33,253,000	103,095,000	100,922,000
Interest income	(338,000)	(92,000)	(649,000)	(162,000)
Gain on debt extinguishment	(23,600,000)	0	(23,600,000)	0
Gain on sale of equity investments and other assets	0	(2,733,000)	0	(124,768,000)
Loss (income) from equity method investments, net	43,082,000	(12,858,000)	164,391,000	(35,282,000)
Other expense	3,194,000	856,000	3,757,000	485,000
Total other (income) expense	56,433,000	18,426,000	246,994,000	(58,805,000)
LOSS BEFORE INCOME TAXES	(628,849,000)	95,150,000	(510,982,000)	296,490,000
INCOME TAX BENEFIT	(144,047,000)	0	(323,378,000)	(69,000)
NET LOSS	$ (484,802,000)	$ 95,150,000	$ (187,604,000)	$ 296,559,000
NET (LOSS) INCOME PER COMMON SHARE:
Basic (in usd per share)	$ (3.04)	$ 0.55	$ (1.17)	$ 1.69
Diluted (in usd per share)	$ (3.04)	$ 0.55	$ (1.17)	$ 1.68
Weighted average common shares outstanding - Basic (in shares)	159,548,477	173,057,538	160,553,796	175,776,312
Weighted average common shares outstanding - Diluted (in shares)	159,548,477	173,304,914	160,553,796	176,440,461
Natural gas sales
Revenues:
Revenue from contract with customer	$ 213,227,000	$ 271,167,000	$ 714,500,000	$ 753,261,000
Oil and condensate sales
Revenues:
Revenue from contract with customer	24,550,000	45,682,000	93,942,000	140,687,000
Natural gas liquid sales
Revenues:
Revenue from contract with customer	$ 20,324,000	$ 53,776,000	$ 78,136,000	$ 141,883,000

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (484,802)	$ 234,956	$ 62,242	$ 95,150	$ 111,319	$ 90,090	$ (187,604)	$ 296,559
Foreign currency translation adjustment	(2,064)			3,052			5,347	(5,815)
Other comprehensive (loss) income	(2,064)	$ 3,610	$ 3,801	3,052	$ (3,364)	$ (5,503)	5,347	(5,815)
Comprehensive (loss) income	$ (486,866)			$ 98,202			$ (182,257)	$ 290,744

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2017		183,105,910
Beginning balance at Dec. 31, 2017	$ 3,101,614	$ 1,831	$ 4,416,250	$ (40,539)	$ (1,275,928)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	90,090				90,090
Other Comprehensive Income (Loss)	(5,503)			(5,503)
Stock Compensation	2,685		2,685
Shares Repurchased (in shares)		(9,692,356)
Shares Repurchased	(99,997)	$ (97)	(99,900)
Issuance of Restricted Stock (in shares)		109,933
Issuance of Restricted Stock	0	$ 1	(1)
Ending balance (in shares) at Mar. 31, 2018		173,523,487
Ending balance at Mar. 31, 2018	3,088,889	$ 1,735	4,319,034	(46,042)	(1,185,838)
Beginning balance (in shares) at Dec. 31, 2017		183,105,910
Beginning balance at Dec. 31, 2017	3,101,614	$ 1,831	4,416,250	(40,539)	(1,275,928)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	296,559
Other Comprehensive Income (Loss)	(5,815)
Ending balance (in shares) at Sep. 30, 2018		173,218,643
Ending balance at Sep. 30, 2018	3,292,015	$ 1,732	4,316,006	(46,354)	(979,369)
Beginning balance (in shares) at Dec. 31, 2017		183,105,910
Beginning balance at Dec. 31, 2017	$ 3,101,614	$ 1,831	4,416,250	(40,539)	(1,275,928)
Ending balance (in shares) at Dec. 31, 2018	162,986,045	162,986,045
Ending balance at Dec. 31, 2018	$ 3,327,768	$ 1,630	4,227,532	(56,026)	(845,368)
Beginning balance (in shares) at Mar. 31, 2018		173,523,487
Beginning balance at Mar. 31, 2018	3,088,889	$ 1,735	4,319,034	(46,042)	(1,185,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	111,319				111,319
Other Comprehensive Income (Loss)	(3,364)			(3,364)
Stock Compensation	3,355		3,355
Shares Repurchased (in shares)		(412,516)
Shares Repurchased	(5,000)	$ (4)	(4,996)
Issuance of Restricted Stock (in shares)		191,084
Issuance of Restricted Stock	0	$ 2	(2)
Ending balance (in shares) at Jun. 30, 2018		173,302,055
Ending balance at Jun. 30, 2018	3,195,199	$ 1,733	4,317,391	(49,406)	(1,074,519)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	95,150				95,150
Other Comprehensive Income (Loss)	3,052			3,052
Stock Compensation	3,614		3,614
Shares Repurchased (in shares)		(400,597)
Shares Repurchased	(5,000)	$ (4)	(4,996)
Issuance of Restricted Stock (in shares)		317,185
Issuance of Restricted Stock	0	$ 3	(3)
Ending balance (in shares) at Sep. 30, 2018		173,218,643
Ending balance at Sep. 30, 2018	$ 3,292,015	$ 1,732	4,316,006	(46,354)	(979,369)
Beginning balance (in shares) at Dec. 31, 2018	162,986,045	162,986,045
Beginning balance at Dec. 31, 2018	$ 3,327,768	$ 1,630	4,227,532	(56,026)	(845,368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	62,242				62,242
Other Comprehensive Income (Loss)	3,801			3,801
Stock Compensation	2,785		2,785
Shares Repurchased (in shares)		(3,618,634)
Shares Repurchased	(28,330)	$ (37)	(28,293)
Issuance of Restricted Stock (in shares)		54,554
Issuance of Restricted Stock	0	$ 1	(1)
Ending balance (in shares) at Mar. 31, 2019		159,421,965
Ending balance at Mar. 31, 2019	$ 3,368,266	$ 1,594	4,202,023	(52,225)	(783,126)
Beginning balance (in shares) at Dec. 31, 2018	162,986,045	162,986,045
Beginning balance at Dec. 31, 2018	$ 3,327,768	$ 1,630	4,227,532	(56,026)	(845,368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(187,604)
Other Comprehensive Income (Loss)	$ 5,347
Ending balance (in shares) at Sep. 30, 2019	159,709,221	159,709,221
Ending balance at Sep. 30, 2019	$ 3,123,104	$ 1,597	4,205,158	(50,679)	(1,032,972)
Beginning balance (in shares) at Mar. 31, 2019		159,421,965
Beginning balance at Mar. 31, 2019	3,368,266	$ 1,594	4,202,023	(52,225)	(783,126)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	234,956				234,956
Other Comprehensive Income (Loss)	3,610			3,610
Stock Compensation	2,846		2,846
Shares Repurchased (in shares)		(296,587)
Shares Repurchased	(2,270)	$ (3)	(2,267)
Issuance of Restricted Stock (in shares)		270,639
Issuance of Restricted Stock	0	$ 3	(3)
Ending balance (in shares) at Jun. 30, 2019		159,396,017
Ending balance at Jun. 30, 2019	3,607,408	$ 1,594	4,202,599	(48,615)	(548,170)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(484,802)				(484,802)
Other Comprehensive Income (Loss)	(2,064)			(2,064)
Stock Compensation	2,651		2,651
Shares Repurchased (in shares)		(35,977)
Shares Repurchased	(89)	$ 0	(89)
Issuance of Restricted Stock (in shares)		349,181
Issuance of Restricted Stock	$ 0	$ 3	(3)
Ending balance (in shares) at Sep. 30, 2019	159,709,221	159,709,221
Ending balance at Sep. 30, 2019	$ 3,123,104	$ 1,597	$ 4,205,158	$ (50,679)	$ (1,032,972)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net (loss) income	$ (187,604,000)	$ 296,559,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Accretion expense	3,173,000	3,056,000
Depletion, depreciation and amortization	406,654,000	352,848,000
Impairment of oil and natural gas properties	571,442,000	0
Stock-based compensation expense	4,969,000	5,792,000
Loss (income) from equity investments	164,532,000	(35,040,000)
Gain on debt extinguishment	(23,600,000)	0
Change in fair value of derivative instruments	(97,425,000)	106,373,000
Deferred income tax benefit	(323,378,000)	(69,000)
Amortization of loan costs	4,821,000	4,554,000
Gain on sale of equity investments and other assets	(178,000)	(124,768,000)
Distributions from equity method investments	2,457,000	1,978,000
Changes in operating assets and liabilities:
Decrease (increase) in accounts receivable—oil and natural gas sales	97,543,000	(10,618,000)
Increase in accounts receivable—joint interest and other	(18,830,000)	(2,277,000)
Increase in accounts receivable—related parties	0	(79,000)
Decrease (increase) in prepaid expenses and other current assets	4,359,000	(4,830,000)
(Increase) decrease in other assets	(30,000)	1,228,000
Increase in accounts payable, accrued liabilities and other	8,567,000	36,809,000
Settlement of asset retirement obligation	(117,000)	(719,000)
Net cash provided by operating activities	617,355,000	630,797,000
Cash flows from investing activities:
Additions to other property and equipment	(4,694,000)	(7,134,000)
Additions to oil and natural gas properties	(646,535,000)	(777,104,000)
Proceeds from sale of oil and natural gas properties	10,864,000	4,820,000
Proceeds from sale of other property and equipment	204,000	217,000
Proceeds from sale of equity method investments	0	226,487,000
Contributions to equity method investments	(432,000)	(2,318,000)
Distributions from equity method investments	1,945,000	446,000
Net cash used in investing activities	(638,648,000)	(554,586,000)
Cash flows from financing activities:
Principal payments on borrowings	(550,500,000)	(165,428,000)
Borrowings on line of credit	640,000,000	225,000,000
Repurchase of senior notes	(79,480,000)	0
Debt issuance costs and loan commitment fees	(211,000)	(772,000)
Payments for repurchase of stock	(30,689,000)	(109,997,000)
Net cash used in financing activities	(20,880,000)	(51,197,000)
Net (decrease) increase in cash, cash equivalents and restricted cash	(42,173,000)	25,014,000
Cash, cash equivalents and restricted cash at beginning of period	52,297,000	99,557,000
Cash, cash equivalents and restricted cash at end of period	10,124,000	124,571,000
Supplemental disclosure of cash flow information:
Interest payments	85,272,000	75,045,000
Income tax receipts	(1,794,000)	0
Supplemental disclosure of non-cash transactions:
Capitalized stock-based compensation	3,313,000	3,862,000
Asset retirement obligation capitalized	6,846,000	1,094,000
Asset retirement obligation removed due to divestiture	(30,035,000)	0
Interest capitalized	2,782,000	3,956,000
Fair value of contingent consideration asset on date of divestiture	(1,137,000)	0
Foreign currency translation gain (loss) on equity method investments	$ 5,347,000	$ (5,815,000)

BASIS OF PRESENTATION AND SUMMA

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	BASIS OF PRESENTATION, RESTATEMENT AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation These consolidated financial statements have been prepared by Gulfport Energy Corporation (the “Company” or “Gulfport”) without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”), and reflect all adjustments that, in the opinion of management, are necessary for a fair presentation of the results for the interim periods reported in all material respects, on a basis consistent with the annual audited consolidated financial statements. All such adjustments are of a normal, recurring nature. Certain information, accounting policies, and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles ("GAAP") have been omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. These consolidated financial statements should be read in conjunction with the consolidated financial statements and the summary of significant accounting policies and notes included in the Company’s most recent annual report on Form 10-K. Results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results expected for the full year. Restatement of Previously Issued Unaudited Consolidated Financial Statements The Company has restated its unaudited consolidated financial statements to correct an error in the balance of unproved oil and natural gas properties, which impacted related depletion, depreciation and amortization and impairment of oil and natural gas properties. This error as of September 30, 2019 was identified in the course of preparing the Company's consolidated financial statements for the year ended December 31, 2019. The following tables present the effect of the error correction discussed above on all affected line items of our previously issued consolidated balance sheets as of September 30, 2019 , consolidated statements of operations for the three and nine months ended September 30, 2019 , consolidated statements of comprehensive income for the three and nine months ended September 30, 2019 , consolidated statements of stockholders' equity for the three months ended September 30, 2019 and the consolidated statements of cash flows for the nine months ended September 30, 2019 . Consolidated Balance Sheets September 30, 2019 As Reported Adjustments As Restated (In thousands) Accumulated depletion, depreciation, amortization and impairment (5,063,413 ) (553,575 ) (5,616,988 ) Property and equipment, net (1) 5,584,533 (553,575 ) 5,030,958 Deferred tax asset 205,853 117,525 323,378 Total other assets 384,278 117,525 501,803 Total assets $ 6,273,148 (436,050 ) $ 5,837,098 Accumulated deficit (596,922 ) (436,050 ) (1,032,972 ) Total stockholders’ equity 3,559,154 (436,050 ) 3,123,104 Total liabilities and stockholders’ equity $ 6,273,148 (436,050 ) $ 5,837,098 (1) Amount excluded from amortization in 2019 $ 2,814,334 (553,575 ) $ 2,260,759 Consolidated Statements of Operations Three Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Depreciation, depletion and amortization $ 145,490 17,780 $ 163,270 Impairment of oil and natural gas properties 35,647 535,795 571,442 Total Costs and Expenses 304,016 553,575 857,591 (LOSS) INCOME FROM OPERATIONS (18,841 ) (553,575 ) (572,416 ) (LOSS) INCOME BEFORE INCOME TAXES (75,274 ) (553,575 ) (628,849 ) INCOME TAX BENEFIT (26,522 ) (117,525 ) (144,047 ) NET (LOSS) INCOME $ (48,752 ) (436,050 ) $ (484,802 ) NET (LOSS) INCOME PER COMMON SHARE: Basic $ (0.31 ) $ (2.73 ) $ (3.04 ) Diluted $ (0.31 ) $ (2.73 ) $ (3.04 ) Nine Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands, except share data) Depreciation, depletion and amortization $ 388,874 17,780 $ 406,654 Impairment of oil and natural gas properties 35,647 535,795 571,442 Total Costs and Expenses 775,160 553,575 1,328,735 (LOSS) INCOME FROM OPERATIONS 289,587 (553,575 ) (263,988 ) (LOSS) INCOME BEFORE INCOME TAXES 42,593 (553,575 ) (510,982 ) INCOME TAX BENEFIT (205,853 ) (117,525 ) (323,378 ) NET (LOSS) INCOME $ 248,446 (436,050 ) $ (187,604 ) NET (LOSS) INCOME PER COMMON SHARE: Basic $ 1.55 $ (2.72 ) $ (1.17 ) Diluted $ 1.51 $ (2.68 ) $ (1.17 ) Weighted average common shares outstanding—Diluted 164,820,002 (4,266,206 ) 160,553,796 Consolidated Statements of Comprehensive Income Three Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Net (loss) income $ (48,752 ) (436,050 ) $ (484,802 ) Comprehensive (loss) income $ (50,816 ) (436,050 ) $ (486,866 ) Nine Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Net (loss) income $ 248,446 (436,050 ) $ (187,604 ) Comprehensive (loss) income $ 253,793 (436,050 ) $ (182,257 ) Consolidated Statements of Stockholders' Equity Accumulated Deficit As Reported Adjustments As Restated (In thousands) Net loss $ (48,752 ) (436,050 ) $ (484,802 ) Balance at September 30, 2019 $ (596,922 ) (436,050 ) $ (1,032,972 ) Total Stockholders' Equity As Reported Adjustments As Restated (In thousands) Net loss $ (48,752 ) (436,050 ) $ (484,802 ) Balance at September 30, 2019 $ 3,559,154 (436,050 ) $ 3,123,104 Consolidated Statements of Cash Flows Nine Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Cash flows from operating activities: Net (loss) income $ 248,446 (436,050 ) $ (187,604 ) Adjustments to reconcile net (loss) income to net cash provided by operating activities: Depletion, depreciation and amortization 388,874 17,780 406,654 Impairment of oil and natural gas properties 35,647 535,795 571,442 Deferred income tax benefit (205,853 ) (117,525 ) (323,378 ) Statements of Cash Flows During the third quarter of 2019, the Company identified that certain activities were misclassified between cash flows from operating activities and cash flows from investing activities. These activities had been included in accounts payable, accrued liabilities and other and presented as cash flows from operating activities while they should have been presented as additions to oil and natural gas properties in cash flows from investing activities. The Company corrected the previously presented statements of cash flows for these additions and in doing so, for the nine months ended September 30, 2018 , the consolidated statements of cash flows and the condensed consolidating statements of cash flows were adjusted to increase net cash flows provided by operating activities by $21.8 million with a corresponding increase in net cash flows used in investing activities. The Company has evaluated the effect of the incorrect presentation, both qualitatively and quantitatively, and concluded that it did not have a material impact on any previously filed annual or quarterly consolidated financial statements. Recently Issued Accounting Pronouncements In February 2016 , the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02 , Leases (Topic 842) . The standard supersedes the previous lease guidance by requiring lessees to recognize a right-to-use asset and lease liability on the balance sheet for all leases with lease terms of greater than one year while maintaining substantially similar classifications for financing and operating leases. Subsequent to ASU 2016-02, the FASB issued several related ASU’s to clarify the application of the lease standard. The Company adopted the new standard as of January 1, 2019 on a prospective basis using the simplified transition method permitted by ASU 2018-11, Leases (Topic 842): Targeted Improvements. The comparative information has not been restated and continues to be reported under the historic accounting standards in effect for those periods. See Note 13 for further discussion of the lease standard. 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. Additionally, in May 2019 , the FASB issued ASU No. 2019-05 , Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief . The amendments in this update allow preparers to irrevocably elect the fair value option, on an instrument-by-instrument basis, for eligible financial assets measured at amortized cost basis upon adoption of 2016-13 . The guidance is effective for periods after December 15, 2019, with early adoption permitted. The Company is in the process of designing processes and controls needed to comply with the requirements of the new standard. Although the standard will have an impact, the Company does not currently anticipate the ASU to have a material effect on its consolidated financial statements and related disclosures. In August 2018 , the FASB issued ASU No. 2018-13 , Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement , which removes, modifies, and adds certain disclosure requirements on fair value measurements. The amendment will be effective for reporting periods beginning after December 15, 2019 , and early adoption is permitted. The Company does not anticipate the new standard to have a material effect on its consolidated financial statements and related disclosures. In August 2018 , the FASB also issued ASU No. 2018-15 , Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , which aligns the accounting for costs associated with implementing a cloud computing arrangement in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software. The amendment will be effective for reporting periods beginning after December 15, 2019 , and early adoption is permitted. The Company does not anticipate the new standard to have a material effect on its consolidated financial statements and related disclosures. In November 2018 , the FASB issued ASU No. 2018-18 , Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606 , which provides guidance on how to assess whether certain transactions between participants in a collaborative arrangement should be accounted for within the ASU No. 2014-09 revenue recognition standard discussed above. The amendment will be effective for reporting periods beginning after December 15, 2019 , and early adoption is permitted. The Company does not anticipate the new standard to have a material effect on its consolidated financial statements and related disclosures. In July 2019, the FASB issued ASU No. 2019-07 , Codification Updates to SEC Sections, Amendments to SEC Paragraphs Pursuant to SEC Final Rule Releases No. 33-10532, Disclosure Update and Simplification, and Nos. 33-10231 and 33-10442, Investment Company Reporting Modernization, and Miscellaneous Updates . This ASU amends various SEC sections within the FASB Codification to align with the updated requirements of certain SEC final rules and includes miscellaneous updates to agree the language in the Codification to the electronic Code of Federal Regulations. ASU No. 2019-07

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	9 Months Ended
	Sep. 30, 2019
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 September 30, 2019 and December 31, 2018 are as follows: September 30, 2019 December 31, 2018 (In thousands) As Restated Oil and natural gas properties $ 10,551,713 $ 10,026,836 Other depreciable property and equipment 90,712 87,146 Land 5,521 5,521 Total property and equipment 10,647,946 10,119,503 Accumulated depletion, depreciation, amortization and impairment (5,616,988 ) (4,640,098 ) Property and equipment, net $ 5,030,958 $ 5,479,405 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 Company's oil and natural gas properties. At September 30, 2019 , the net book value of the Company's oil and gas properties, less related deferred income taxes, was above the calculated ceiling as a result of reduced commodity prices for the period leading up to September 30, 2019 . As a result, the Company was required to record an impairment of its oil and natural gas properties under the full cost method of accounting in the amount of $571.4 million (as restated) for the three and nine months ended September 30, 2019 . No impairment was required for oil and natural gas properties for the three and nine months ended September 30, 2018 . Additional impairments of oil and natural gas properties are expected to occur in upcoming quarters should commodity prices continue below the average of the previous 12 months. However, the amount of any future impairments is difficult to predict as it depends on changes in commodity prices, production rates, proved reserves, evaluation of costs excluded from amortization, future development costs and production costs. Included in oil and natural gas properties at September 30, 2019 is the cumulative capitalization of $229.6 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 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 $9.8 million and $26.3 million for the three and nine months ended September 30, 2019 , respectively, and $10.6 million and $28.8 million for the three and nine months ended September 30, 2018 , respectively. The average depletion rate per Mcfe, which is a function of capitalized costs, future development costs and the related underlying reserves in the periods presented, was $1.05 (as restated) and $0.94 per Mcfe for the nine months ended September 30, 2019 and 2018 , respectively. The following table summarizes the Company’s unproved properties excluded from amortization by area at September 30, 2019 : September 30, 2019 (In thousands) As Restated Utica $ 1,112,148 MidContinent 1,148,271 Other 340 $ 2,260,759 At December 31, 2018 , approximately $2.9 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 in the Utica Shale have five-year extension terms which could extend this time frame beyond five years. Divestitures In December of 2018, the Company entered into an agreement to sell its non-core assets located in the West Cote Blanche Bay ("WCBB") and Hackberry fields of Louisiana to an undisclosed third party for a purchase price of approximately $19.7 million . The sale closed on July 3, 2019, subject to customary post-closing terms and conditions, with an effective date of August 15, 2018. The Company received approximately $9.2 million in cash and retained contingent overriding royalty interests. In addition, the Company could also receive contingent payments based on commodity prices exceeding specified thresholds over the two years following the closing date. See Note 9 for further discussion of the contingent consideration arrangement, which was determined to be an embedded derivative. The buyer assumed all plugging and abandonment liabilities associated with these assets which totaled approximately $30.0 million at the divestiture date. Asset Retirement Obligation A reconciliation of the Company’s asset retirement obligation for the nine months ended September 30, 2019 and 2018 is as follows: September 30, 2019 September 30, 2018 (In thousands) Asset retirement obligation, beginning of period $ 79,952 $ 75,100 Liabilities incurred 5,769 1,468 Liabilities settled (117 ) (719 ) Liabilities removed due to divestitures (30,035 ) — Accretion expense 3,173 3,056 Revisions in estimated cash flows 1,077 (374 ) Asset retirement obligation as of end of period 59,819 78,531 Less current portion — 120 Asset retirement obligation, long-term $ 59,819 $ 78,411

EQUITY INVESTMENTS

EQUITY INVESTMENTS	9 Months Ended
	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
EQUITY INVESTMENTS	EQUITY INVESTMENTS Investments accounted for by the equity method consist of the following as of September 30, 2019 and December 31, 2018 : Carrying value Loss (income) from equity method investments Approximate ownership % September 30, 2019 December 31, 2018 Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (In thousands) Investment in Tatex Thailand II, LLC 23.5 % $ — $ — $ — $ (137 ) $ (2,085 ) $ (241 ) Investment in Grizzly Oil Sands ULC 24.9999 % 49,546 44,259 41 275 380 833 Investment in Timber Wolf Terminals LLC (1) — % — — — — — 536 Investment in Windsor Midstream LLC 22.5 % 39 39 — — — (9 ) Investment in Mammoth Energy Services, Inc. 21.8 % 24,377 191,823 43,041 (12,996 ) 166,096 (35,708 ) Investment in Strike Force Midstream LLC (2) — % — — — — — (693 ) $ 73,962 $ 236,121 $ 43,082 $ (12,858 ) $ 164,391 $ (35,282 ) (1) On June 5, 2018, the Company received its final distribution from Timber Wolf Terminals LLC ("Timber Wolf"). See below under Timber Wolf Terminals LLC for information regarding the subsequent dissolution of Timber Wolf. (2) On May 1, 2018, the Company sold its 25% interest in Strike Force Midstream LLC ("Strike Force") to EQT Midstream Partners, LP. See below under Strike Force Midstream LLC for information regarding this transaction. The tables below summarize financial information for the Company’s equity investments as of September 30, 2019 and December 31, 2018 . Summarized balance sheet information: September 30, 2019 December 31, 2018 (In thousands) Current assets $ 427,643 $ 471,733 Noncurrent assets $ 1,309,729 $ 1,302,488 Current liabilities $ 130,465 $ 239,975 Noncurrent liabilities $ 176,145 $ 94,575 Summarized results of operations: Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (In thousands) Gross revenue $ 113,417 $ 384,043 $ 557,375 $ 1,451,580 Net (loss) income $ (35,730 ) $ 68,414 $ (15,046 ) $ 181,884 Tatex Thailand II, LLC The Company has an indirect ownership interest in Tatex Thailand II, LLC ("Tatex II"). Tatex II held an 8.5% interest in APICO, LLC (“APICO”), an international oil and gas exploration company, before selling its interest in June 2019. APICO has a reserve base located in Southeast Asia through its ownership of concessions covering approximately 108,000 acres which includes the Phu Horm Field. The Company received $2.1 million in distributions from Tatex II during the nine months ended September 30, 2019 , of which $1.9 million related to proceeds from the sale of its interest in APICO. Grizzly Oil Sands ULC The Company, through its wholly owned subsidiary Grizzly Holdings Inc. (“Grizzly Holdings”), owns an approximate 24.9999% 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 September 30, 2019 , Grizzly had approximately 830,000 acres under lease in the Athabasca, Peace River and Cold Lake oil sands regions of Alberta, Canada. The Company reviewed its investment in Grizzly for impairment at September 30, 2019 and 2018 and determined no impairment was required. If commodity prices decline in the future however, impairment of the Company's investment in Grizzly may be necessary. During the nine months ended September 30, 2019 , Gulfport paid $0.4 million in cash calls. Grizzly’s functional currency is the Canadian dollar. The Company’s investment in Grizzly was decreased by a $2.0 million foreign currency translation loss and increased by a $5.2 million foreign currency translation gain for the three and nine months ended September 30, 2019 , respectively. The Company's investment in Grizzly was increased by a $2.9 million foreign currency translation gain and decreased by a $5.7 million foreign currency translation loss for the three and nine months ended September 30, 2018 , respectively. Timber Wolf Terminals LLC During 2012, the Company invested in Timber Wolf. Timber Wolf was formed to operate a crude/condensate terminal and a sand transloading facility in Ohio. Timber Wolf was dissolved in 2018. Windsor Midstream LLC At September 30, 2019 , the Company held a 22.5% interest in Windsor Midstream LLC (“Midstream”), an entity controlled and managed by an unrelated third party. The Company received no distributions from Midstream during the nine months ended September 30, 2019 . The Company has determined that Midstream is a variable interest entity ("VIE") but that the Company is not the primary beneficiary because it does not have a controlling financial interest in Midstream. This entity is considered a VIE because the limited partners lack substantive kick-out or participating rights over the general partner. The general partner has power to direct the activities that most significantly impact Midstream's economic performance. The Company accounts for its investment in 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 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. Mammoth Energy Services, Inc. At September 30, 2019 , the Company owned 9,829,548 shares, or approximately 21.8% , of the outstanding common stock of Mammoth Energy Services, Inc. ("Mammoth Energy"). The Company reviewed its investment in Mammoth Energy as of September 30, 2019 for impairment based on certain qualitative and quantitative factors. As a result of the calculated fair values and other qualitative factors, the Company concluded that an other than temporary impairment was indicated. This resulted in recording an impairment loss of $35.5 million and $160.8 million for the three and nine months ended September 30, 2019 , which is included in loss (income) from equity method investments, net in the accompanying consolidated statements of operations. If Mammoth Energy's common stock continues to trade below the Company's carrying value for a prolonged period of time, further impairment of the Company's investment in Mammoth Energy may be necessary. The Company’s investment in Mammoth Energy was decreased by a $0.1 million foreign currency loss and increased by a $0.1 million foreign currency gain resulting from Mammoth Energy's foreign subsidiary for the three and nine months ended September 30, 2019 , respectively . The Company’s investment in Mammoth Energy was increased by a $0.1 million foreign currency gain and decreased by a $0.2 million foreign currency loss resulting from Mammoth Energy’s foreign subsidiary for the three and nine months ended September 30, 2018 , respectively. During the nine months ended September 30, 2019 , Gulfport received distributions of $2.5 million from Mammoth Energy as a result of $0.125 per share dividends in February 2019 and May 2019. The approximate fair value of the Company's investment in Mammoth Energy's common stock at September 30, 2019 was $24.4 million based on the quoted market price of Mammoth Energy's common stock. The loss (income) 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”), then a subsidiary of Rice Energy Inc., to develop natural gas gathering assets in eastern Belmont County and Monroe County, Ohio through Strike Force. In 2017, Rice was acquired by EQT Corporation ("EQT"). The Company owned a 25%

LONG-TERM DEBT

LONG-TERM DEBT	9 Months Ended
	Sep. 30, 2019
Long-term Debt, Unclassified [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT Long-term debt consisted of the following items as of September 30, 2019 and December 31, 2018 : September 30, 2019 December 31, 2018 (In thousands) Revolving credit agreement (1) $ 135,000 $ 45,000 6.625% senior unsecured notes due 2023 340,000 350,000 6.000% senior unsecured notes due 2024 630,796 650,000 6.375% senior unsecured notes due 2025 577,268 600,000 6.375% senior unsecured notes due 2026 397,529 450,000 Net unamortized debt issuance costs (2) (26,052 ) (30,733 ) Construction loan 22,650 23,149 Less: current maturities of long term debt (622 ) (651 ) Debt reflected as long term $ 2,076,569 $ 2,086,765 (1) The Company has entered into a senior secured revolving credit facility, as amended (the "revolving credit facility"), with The Bank of Nova Scotia, as the lead arranger and administrative agent and other lenders. On June 3, 2019, the Company further amended its revolving credit facility to, among other things, allow the Company to designate certain of its subsidiaries as unrestricted subsidiaries and to include LIBOR replacement provisions. Additionally, the borrowing base was reaffirmed at $1.4 billion , and the Company’s elected commitment amount remained at $1.0 billion . As of September 30, 2019 , $135.0 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 $248.6 million letters of credit, was $616.4 million . The Company’s wholly owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. At September 30, 2019 , amounts borrowed under the revolving credit facility bore interest at a weighted average rate of 3.52% . The Company was in compliance with its financial covenants under the revolving credit facility at September 30, 2019 . (2) Loan issuance costs related to the 6.625% Senior Notes due 2023 (the "2023 Notes"), the 6.000% Senior Notes due 2024 (the "2024 Notes"), the 6.375% Senior Notes due 2025 (the "2025 Notes") and the 6.375% Senior Notes due 2026 (the "2026 Notes") (collectively the “Notes”) have been presented as a reduction to the principal amount of the Notes. At September 30, 2019 , total unamortized debt issuance costs were $3.6 million for the 2023 Notes, $7.5 million for the 2024 Notes, $10.8 million for the 2025 Notes and $4.0 million for the 2026 Notes. In addition, loan commitment fee costs for the Company's construction loan agreement were $0.1 million at September 30, 2019 . The Company capitalized approximately $1.0 million and $2.8 million in interest expense to undeveloped oil and natural gas properties during the three and nine months ended September 30, 2019 , respectively. The Company capitalized approximately $1.6 million and $4.0 million in interest expense to undeveloped oil and natural gas properties during the three and nine months ended September 30, 2018 , respectively. Debt Repurchases During the three months ended September 30, 2019 , the Company used borrowings under its revolving credit facility to repurchase in the open market approximately $104.4 million aggregate principal amount of its outstanding Notes for $80.3 million . This included approximately $10.0 million principal amount of the 2023 Notes, $19.2 million principal amount of the 2024 Notes, $22.7 million principal amount of the 2025 Notes, and $52.5 million principal amount of the 2026 Notes. The Company recognized a $23.6 million

COMMON STOCK AND CHANGES IN CAP

COMMON STOCK AND CHANGES IN CAPITALIZATION	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
COMMON STOCK AND CHANGES IN CAPITALIZATION	COMMON STOCK AND CHANGES IN CAPITALIZATION Stock Repurchase Program In January 2018, the board of directors of the Company approved a stock repurchase program to acquire up to $100 million of the Company's outstanding stock during 2018. In May 2018, the Company's board of directors authorized the expansion of its stock repurchase program, authorizing the Company to acquire up to an additional $100 million of its outstanding common stock during 2018 for a total of up to $200 million . The repurchase program did not require the Company to acquire any specific number of shares. This repurchase program was authorized to extend through December 31, 2018 and the Company repurchased 20.7 million shares of common stock in 2018 for $200.0 million in aggregate consideration. In January 2019, the board of directors of the Company approved a new stock repurchase program to acquire a portion of the Company's outstanding common stock within a 24 month period. Purchases under the repurchase program may be made from time to time in open market or privately negotiated transactions, and are subject to market conditions, applicable legal requirements, contractual obligations and other factors. The repurchase program does not require the Company to acquire any specific number of shares. This repurchase program is authorized to extend through December 31, 2020 and may be suspended, modified, extended or discontinued by the board of directors at any time. The Company did not repurchase any shares under the program during the three months ended September 30, 2019 , and repurchased approximately 3.8 million shares for a cost of approximately $30.0 million during the nine months ended September 30, 2019 . Additionally, during each of the three and nine months ended September 30, 2019 , the Company repurchased approximately 0.1 million shares for a cost of approximately $0.1 million and $0.7 million

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION The Company has granted restricted stock units to employees and directors pursuant to the 2019 Amended and Restated Incentive Stock Plan ("2019 Plan"), as discussed below. During the three and nine months ended September 30, 2019 , the Company’s stock-based compensation cost was $2.7 million and $8.3 million , respectively, of which the Company capitalized $1.1 million and $3.3 million , respectively, relating to its exploration and development efforts. During the three and nine months ended September 30, 2018 , the Company's stock-based compensation cost was $3.6 million and $9.7 million , respectively, of which the Company capitalized $1.4 million and $3.9 million , respectively, relating to its exploration and development efforts. Stock compensation costs, net of the amounts capitalized, are included in general and administrative expenses in the accompanying consolidated statements of operations. The following table summarizes restricted stock unit activity for the nine months ended September 30, 2019 : Number of Unvested Restricted Stock Units Weighted Average Grant Date Fair Value Number of Unvested Performance Vesting Restricted Stock Units Weighted Average Grant Date Fair Value Unvested shares as of January 1, 2019 1,535,811 $ 11.57 $ — $ — Granted 4,011,073 3.74 2,009,144 2.85 Vested (674,374 ) 12.86 — — Forfeited (289,610 ) 7.83 (112,742 ) 1.98 Unvested shares as of September 30, 2019 4,582,900 $ 4.76 1,896,402 $ 2.91 Restricted Stock Units Restricted stock units awarded under the 2019 Plan generally vest over a period of one year in the case of directors and three years in the case of employees and vesting is dependent upon the recipient meeting applicable service requirements. Stock-based compensation costs are recorded ratably over the service period. The grant date fair value of restricted stock units represents the closing market price of the Company's common stock on the date of grant. Unrecognized compensation expense as of September 30, 2019 related to restricted stock units was $19.0 million . The expense is expected to be recognized over a weighted average period of 2.28 years. Performance Vesting Restricted Stock Units During the nine months ended September 30, 2019 , the Company awarded performance vesting units to certain of its executive officers under the 2019 Plan. The number of shares of common stock issued pursuant to the award will be based on relative total shareholder return ("RTSR"). RTSR is an incentive measure whereby participants will earn from 0% to 200% of the target award based on the Company’s RTSR ranking compared to the RTSR of the companies in the Company’s designated peer group at the end of the performance period. Awards will be earned and vested over a performance period measured from January 1, 2019 to December 31, 2021, subject to earlier termination of the performance period in the event of a change in control. The grant date fair value was determined using the Monte Carlo simulation method and is being recorded ratably over the performance period. Expected volatilities utilized in the Monte Carlo model were estimated using a historical period consistent with the remaining performance period of approximately two years . The risk-free interest rates were based on the U.S. Treasury rate for a term commensurate with the expected life of the grant. The Company assumed a range of risk-free interest rates of 1.56% to 2.42% and a range of expected volatilities of 29.1% to 85.1% to estimate the fair value of performance vesting units granted during the nine months ended September 30, 2019 . Unrecognized compensation expense as of September 30, 2019 related to performance vesting restricted shares was $4.9 million . The expense is expected to be recognized over a weighted average period of 2.64 years.

EARNINGS PER SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
EARNINGS PER SHARE	ER SHARE Reconciliations of the components of basic and diluted net income per common share are presented in the tables below: Three months ended September 30, 2019 2018 Loss Shares Per Share Income Shares Per Share (In thousands, except share data) Basic: Net (loss) income (as restated) $ (484,802 ) 159,548,477 $ (3.04 ) $ 95,150 173,057,538 $ 0.55 Effect of dilutive securities: Stock options and awards — — — 247,376 Diluted: Net (loss) income (as restated) $ (484,802 ) 159,548,477 $ (3.04 ) $ 95,150 173,304,914 $ 0.55 Nine months ended September 30, 2019 2018 Income Shares Per Income Shares Per (In thousands, except share data) Basic: Net (loss)income (as restated) $ (187,604 ) 160,553,796 $ (1.17 ) $ 296,559 175,776,312 $ 1.69 Effect of dilutive securities: Stock options and awards (as restated) — — — 664,149 Diluted: Net (loss) income (as restated) $ (187,604 ) 160,553,796 $ (1.17 ) $ 296,559 176,440,461 $ 1.68 There were 2,073,638 and 4,266,206 (as restated) shares of common stock that were considered anti-dilutive for the three and nine months ended September 30, 2019 , respectively. There were no potential shares of common stock that were considered anti-dilutive for the three and nine months ended September 30, 2018 .

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Firm Transportation and Sales Commitments The table below presents the firm sales commitments by year: (MMBtu per day) Remaining 2019 424,000 2020 314,000 2021 192,000 2022 70,000 2023 17,000 Thereafter — Total 1,017,000 The table below presents the firm transportation commitments by year: (In thousands) Remaining 2019 $ 65,763 2020 287,627 2021 286,665 2022 286,665 2023 282,981 Thereafter 2,410,866 Total $ 3,620,567 Other Commitments Effective October 1, 2014, the Company entered into a Sand Supply Agreement with Muskie Proppant LLC (“Muskie”), a subsidiary of Mammoth Energy and a related party. Pursuant to this agreement, as amended effective August 3, 2018, 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 through 2021. 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 $0.02 million and $0.4 million in non-utilization fees under this agreement during the three and nine months ended September 30, 2019 , respectively. The Company incurred $1.3 million and $1.5 million in non-utilization fees under this agreement during the three and nine months ended September 30, 2018 . Future minimum commitments under this agreement at September 30, 2019 are: (In thousands) Remaining 2019 $ 6,000 2020 24,000 2021 24,000 Total $ 54,000 Litigation and Regulatory Proceedings The Company is involved in a number of litigation and regulatory proceedings including those described below. Many of these proceedings are in early stages, and many of them seek or may seek damages and penalties, the amount of which is indeterminate. The Company's total accrued liabilities in respect of litigation and regulatory proceedings is determined on a case-by-case basis and represents an estimate of probable losses after considering, among other factors, the progress of each case or proceeding, its experience and the experience of others in similar cases or proceedings, and the opinions and views of legal counsel. Significant judgment is required in making these estimates and their final liabilities may ultimately be materially different. The Company, along with a number of other oil and gas companies, has been named as a defendant 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 15th Judicial District of the State of Louisiana in the 15th Judicial District Court for the Parish of Vermilion on July 29, 2016 (together, the "Complaints"). The Complaints allege that certain of the defendants’ operations violated the State and Local Coastal Resources Management Act of 1978, as amended, and the rules, regulations, orders and ordinances adopted thereunder (the "CZM Laws") by causing substantial damage to land and waterbodies located in the coastal zone of the relevant Parish. 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 interest. The United States District Court for the Western District of Louisiana issued orders remanding the cases to their respective state court, and the defendants have appealed the remand orders to the 5th Circuit Court of Appeals. In July 2019, Pigeon Land Company, Inc., a successor in interest to certain of the Company’s legacy Louisiana properties, filed an action against the Company and a number of other oil and gas companies in the 16th Judicial District Court for the Parish of Iberia in Louisiana. The suit alleges negligence, strict liability and various violations of Louisiana statutes relating to property damage in connection with the historic development of the Company’s Louisiana properties and seeks unspecified damages (including punitive damages), an injunction to return the affected property to its original condition, and the payment of reasonable attorney fees and legal expenses and interest. In September 2019, a stockholder of Mammoth Energy filed a derivative action on behalf of Mammoth Energy against members of Mammoth Energy’s board of directors, including a director designated by the Company, and its significant stockholders, including the Company, in the United States District Court for the Western District of Oklahoma. The complaint alleges, among other things, that the members of Mammoth Energy’s board of directors breached their fiduciary duties and violated the Securities Exchange Act of 1934, as amended, in connection with Mammoth Energy’s activities in Puerto Rico following Hurricane Maria. The complaint seeks unspecified damages, the payment of reasonable attorney fees and legal expenses and interest and to force Mammoth Energy and its board of directors to make specified corporate governance reforms. In October 2019, Saydee Resources, LLC, on behalf of itself and a class of similarly situated royalty holders, filed an action against the Company in the District Court of Grady County Oklahoma. The suit alleges that the Company underpaid royalty holders and seeks unspecified damages for breach of contract, tortious breach of contract, fraud and unjust enrichment. In October 2019, Kelsie Wagner, in her capacity as trustee of various trusts and on behalf of the trusts and other similarly situated royalty owners, filed an action against the Company in the District Court of Grady County, Oklahoma. The suit alleges that the Company underpaid royalty owners and seeks unspecified damages for violations of the Oklahoma Production Revenue Standards Act and fraud. These cases are still in their early stages. As a result, the Company has not had the opportunity to evaluate the allegations made in the plaintiffs' complaints and intends to vigorously defend the suits. The Company filed an action against TH Exploration, LLC ("TH") in Tarrant County, Texas. The suit alleges breach of purchase and sale agreement providing for the Company's disposition of certain oil and gas properties in Ohio to TH. The Company is seeking specific performance, related to TH's obligations to close the transaction and tender the purchase price, along with any additional relief available to the Company. SEC Investigation The SEC has commenced an investigation with respect to certain actions by former Company management, including alleged improper personal use of Company assets, and potential violations by former management and the Company of the Sarbanes-Oxley Act of 2002 in connection with such actions. The Company has fully cooperated and intends to continue to cooperate fully with the SEC’s investigation. Although it is not possible to predict the ultimate resolution or financial liability with respect to this matter, the Company believes that the outcome of this matter will not have a material effect on the Company’s business, financial condition or results of operations. Business Operations The Company is involved in various lawsuits and disputes incidental to its business operations, including commercial disputes, personal injury claims, royalty claims, property damage claims and contract actions. Environmental Contingencies The nature of the oil and gas business carries with it certain environmental risks for Gulfport and its subsidiaries. They have implemented various policies, programs, procedures, training and audits to reduce and mitigate such environmental risks. They conduct periodic reviews, on a company-wide basis, to assess changes in their environmental risk profile. Environmental reserves are established for environmental liabilities for which economic losses are probable and reasonably estimable. The Company manages its exposure to environmental liabilities in acquisitions by using an evaluation process that seeks to identify pre-existing contamination or compliance concerns and address the potential liability. Depending on the extent of an identified environmental concern, they may, among other things, exclude a property from the transaction, require the seller to remediate the property to their satisfaction in an acquisition or agree to assume liability for the remediation of the property. The Company received several Finding of Violation (“FOVs”) from the United States Environmental Protection Agency ("USEPA") alleging violations of the Clean Air Act at approximately 12 locations in Ohio. The first FOV for one site was dated December 11, 2013. Two subsequent FOVs incorporated and expanded the scope on January 4, 2017 and April 15, 2019. The Company has exchanged information with the USEPA and is engaged in discussions aimed at resolving the allegations. Resolution of the matter may result in monetary sanctions of more than $100,000 . Other Matters Based on management’s current assessment, they are of the opinion that no pending or threatened lawsuit or dispute relating to its business operations is likely to have a material adverse effect on their future consolidated financial position, results of operations or cash flows. The final resolution of such matters could exceed amounts accrued, however, and actual results could differ materially from management’s estimates.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	9 Months Ended
	Sep. 30, 2019
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 ("NGLs") 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 NGLs 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, the NYMEX West Texas Intermediate for oil and Mont Belvieu for propane, pentane and ethane. Below is a summary of the Company’s open fixed price swap positions as of September 30, 2019 . Location Daily Volume (MMBtu/day) Weighted Remaining 2019 NYMEX Henry Hub 1,380,000 $ 2.81 2020 NYMEX Henry Hub 519,000 $ 2.88 Location Daily Volume Weighted Remaining 2019 NYMEX WTI 6,000 $ 60.81 2020 NYMEX WTI 6,000 $ 59.82 Location Daily Volume Weighted Remaining 2019 Mont Belvieu C2 1,000 $ 18.48 Remaining 2019 Mont Belvieu C3 4,000 $ 29.02 Remaining 2019 Mont Belvieu C5 1,000 $ 53.71 The Company sold call options in exchange for a premium, and used the associated premiums to enhance the fixed price for a portion of the fixed price natural gas swaps primarily for 2020 listed above. Each call option has an established ceiling price. When the referenced settlement price is above the price ceiling established by these 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 2019 NYMEX Henry Hub 30,000 $ 3.10 2022 NYMEX Henry Hub 628,000 $ 2.90 2023 NYMEX Henry Hub 628,000 $ 2.90 For a portion of the natural gas fixed price swaps listed above, the counterparty had the option to extend the original terms for an additional twelve months for the period of January 2019 through December 2019. In December 2018, the counterparties chose to exercise all natural gas fixed price swaps, resulting in an additional 100,000 MMBtu per day at a weighted average price of $3.05 per MMBtu, which is included in the natural gas fixed price swaps listed above. In addition, the Company entered into natural gas basis swap positions. As of September 30, 2019 , the Company had the following natural gas basis swap positions open: Gulfport Pays Gulfport Receives Daily Volume (MMBtu/day) Weighted Average Fixed Spread Remaining 2019 Transco Zone 4 NYMEX Plus Fixed Spread 60,000 $ (0.05 ) 2020 Transco Zone 4 NYMEX Plus Fixed Spread 60,000 $ (0.05 ) 2020 Fixed Spread ONEOK Minus NYMEX 10,000 $ (0.54 ) Contingent Consideration Arrangement The purchase and sale agreement for the sale of the Company's non-core assets located in the WCBB and Hackberry fields of Louisiana included a contingent consideration arrangement that entitles the Company to receive bonus payments if commodity prices exceed specified thresholds. The calculated fair value of this contingent payment arrangement was approximately $1.1 million as of the closing date of the divestiture. See below for threshold and potential payment amounts. Period Threshold (1) Payment to be received (2) July 2020 - June 2021 Greater than or equal to $60.65 $ 150,000 Between $52.62 - $60.65 Calculated Value (3) Less than or equal to $52.62 $ — (1) Based on the "WTI NYMEX + Argus LLS Differential," as published by Argus Media. (2) Payment will be assessed monthly from July 2020 through June 2021. If threshold is met, payment shall be received within five business days after the end of each calendar month. (3) If average daily price, as defined in (1), is greater than $52.62 but less than $60.65, payment received will be $150,000 multiplied by a fraction, the numerator of which is the amount determined by subtracting $52.62 from such average daily price, and the denominator of which is $8.03. 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 September 30, 2019 and December 31, 2018 : September 30, 2019 December 31, 2018 (In thousands) Commodity derivative instruments $ 134,511 $ 21,352 Contingent consideration arrangement 60 — Total short-term derivative instruments - asset $ 134,571 $ 21,352 Commodity derivative instruments $ 23,375 $ — Contingent consideration arrangement 44 — Total long-term derivative instruments - asset $ 23,419 $ — Total short-term derivative instruments - liability $ 429 $ 20,401 Total long-term derivative instruments - liability $ 72,040 $ 13,992 Gains and Losses The following table presents the gain and loss recognized in net gain (loss) on natural gas, oil and NGLs derivatives in the accompanying consolidated statements of operations for the three and nine months ended September 30, 2019 and 2018 . Net gain (loss) on derivative instruments Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (In thousands) Natural gas derivatives $ 11,731 $ 14,101 $ 147,774 $ (26,789 ) Oil derivatives 12,736 (11,610 ) 24,153 (45,176 ) NGLs derivatives 3,641 (12,154 ) 7,276 (24,772 ) Contingent consideration arrangement (1,034 ) — (1,034 ) — Total $ 27,074 $ (9,663 ) $ 178,169 $ (96,737 ) 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 September 30, 2019 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 157,990 $ (72,469 ) $ 85,521 Derivative liabilities $ (72,469 ) $ 72,469 $ — As of December 31, 2018 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 21,352 $ (19,289 ) $ 2,063 Derivative liabilities $ (34,393 ) $ 19,289 $ (15,104 ) 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	9 Months Ended
	Sep. 30, 2019
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. Fair value is 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. Market or observable inputs are the preferred sources of values, followed by assumptions based on hypothetical transactions in the absence of market inputs. Fair value measurements are 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 valuation level as of September 30, 2019 and December 31, 2018 : September 30, 2019 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 157,990 $ — Liabilities: Derivative Instruments $ — $ 72,469 $ — December 31, 2018 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 21,352 $ — Liabilities: Derivative Instruments $ — $ 34,393 $ — The Company estimates the fair value of all derivative instruments using industry-standard models that consider 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 fair value of the Company's investment in Mammoth Energy as of September 30, 2019 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. 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 nine months ended September 30, 2019 were approximately $5.8 million .

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 2019
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 Company's 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 September 30, 2019 , the carrying value of the outstanding debt represented by the Notes was approximately $1.9 billion , including the unamortized debt issuance cost of approximately $3.6 million related to the 2023 Notes, approximately $7.5 million related to the 2024 Notes, approximately $10.8 million related to the 2025 Notes and approximately $4.0 million related to the 2026 Notes. Based on the quoted market price, the fair value of the Notes was determined to be approximately $1.4 billion at September 30, 2019

REVENUE FROM CONTRACTS WITH CUS

REVENUE FROM CONTRACTS WITH CUSTOMERS	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
REVENUE FROM CONTRACTS WITH CUSTOMERS	REVENUE FROM CONTRACTS WITH CUSTOMERS Revenue Recognition The Company’s revenues are primarily derived from the sale of natural gas, oil and condensate and NGLs. Sales of natural gas, oil and condensate and NGLs are recognized in the period that the performance obligations are satisfied. The Company generally considers the delivery of each unit (MMBtu or Bbl) to be separately identifiable and represents a distinct performance obligation that is satisfied at the time control of the product is transferred to the customer. Revenue is measured based on consideration specified in the contract with the customer, and excludes any amounts collected on behalf of third parties. These contracts typically include variable consideration that is based on pricing tied to market indices and volumes delivered in the current month. As such, this market pricing may be constrained (i.e., not estimable) at the inception of the contract but will be recognized based on the applicable market pricing, which will be known upon transfer of the goods to the customer. The payment date is usually within 30 days of the end of the calendar month in which the commodity is delivered. A significant number of the Company's product sales are short-term in nature generally through evergreen contracts with contract terms of one year or less, and the Company's product sales that have a contractual term greater than one year have no long-term fixed consideration. Contract Balances Receivables from contracts with customers are recorded when the right to consideration becomes unconditional, generally when control of the product has been transferred to the customer. Receivables from contracts with customers were $112.7 million and $210.2 million as of September 30, 2019 and December 31, 2018 , respectively, and are reported in accounts receivable - oil and natural gas sales on the consolidated balance sheets. The Company currently has no assets or liabilities related to its revenue contracts, including no upfront or rights to deficiency payments. Prior-Period Performance Obligations The Company records revenue in the month production is delivered to the purchaser. However, settlement statements for certain sales may be received for 30 to 90 days after the date production is delivered, and as a result, the Company is required to estimate the amount of production that was delivered to the purchaser and the price that will be received for the sale of the product. The differences between the estimates and the actual amounts for product sales is recorded in the month that payment is received from the purchaser. For the nine months ended September 30, 2019 , revenue recognized in the reporting period related to performance obligations satisfied in prior reporting periods was not material.

LEASES

LEASES	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
LEASES	LEASES Effective January 1, 2019, the Company adopted ASU No. 2016-02, Leases (Topic 842) . The new standard supersedes the previous lease guidance by requiring lessees to recognize a right-of-use asset and lease liability on the balance sheet for all leases with lease terms of greater than one year while maintaining substantially similar classifications for financing and operating leases. The Company adopted the new standard on a prospective basis using the simplified transition method permitted by ASU No. 2018-11, Leases (Topic 842): Targeted Improvements . Offsetting right-of-use assets and corresponding lease liabilities recognized by the Company on the adoption date totaled approximately $110 million , representing minimum payment obligations associated with identified leases with contractual durations exceeding one year. No cumulative-effect adjustment to retained earnings was required upon adoption of the new standard. The Company elected the package of practical expedients permitted under the new standard, which among other things, allows for lease and non-lease components in a contract to be accounted for as a single lease component for all asset classes and the carry forward of historical lease classifications. Nature of Leases The Company has operating leases associated with drilling rig commitments, pressure pumping services, field offices and other equipment with remaining lease terms with contractual durations in excess of one year. Short-term leases that have an initial term of one year or less are not capitalized. The Company has entered into contracts for drilling rigs with third parties to ensure rig availability in its key operating areas. The Company has concluded its drilling rig contracts are operating leases as the assets are identifiable and the evaluation that the Company has the right to control the identified assets. The Company's drilling rig commitments are typically structured with an initial term of one to two years and expire at various dates through 2021. These agreements typically include renewal options at the end of the initial term. Due to the nature of the Company's drilling schedules and potential volatility in commodity prices, the Company is unable to determine at commencement with reasonable certainty if the renewal options will be exercised; therefore, renewal options are not considered in the lease term for drilling contracts. The operating lease liabilities associated with these rig commitments are based on the minimum contractual obligations, primarily standby rates, and do not include variable amounts based on actual activity in a given period. Pursuant to the full cost method of accounting, these costs are capitalized as part of oil and natural gas properties on the accompanying consolidated balance sheets. A portion of these costs are borne by other interest owners. 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 and a related party. Pursuant to this agreement, as amended effective July 1, 2018, Stingray Pressure has agreed to provide hydraulic fracturing, stimulation and related completion and rework services to the Company through 2021 and the Company has agreed to pay Stingray Pressure a monthly service fee plus the associated costs of the services provided. The Company has the right to suspend services of one crew and only one crew at any point in time without payment, fee or other obligation associated with the suspended crew, given appropriate notification of suspension. The Company has determined that the agreement with Stingray Pressure is an operating lease due to the implicit identification of assets and the evaluation that the Company has the right to control the identified assets. The operating lease liability associated with this agreement is based on the minimum contractual obligations, which is the monthly service fee for one crew, and does not include variable amounts based on actual activity in a given period. Pursuant to the full cost method of accounting, these costs are capitalized as part of oil and natural gas properties on the accompanying consolidated balance sheets. A portion of these costs are borne by other interest owners. The Company rents office space for its field locations and certain other equipment from third parties, which expire at various dates through 2024. These agreements are typically structured with non-cancelable terms of one to five years . The Company has determined these agreements represent operating leases with a lease term that equals the primary non-cancelable contract term. The Company has included any renewal options that it has determined are reasonably certain of exercise in the determination of the lease terms. Discount Rate As most of the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The Company's incremental borrowing rate reflects the estimated rate of interest that it would pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. Maturities of operating lease liabilities as of September 30, 2019 were as follows: (In thousands) Remaining 2019 $ 10,190 2020 31,460 2021 22,731 2022 115 2023 90 Thereafter 30 Total lease payments $ 64,616 Less: Imputed interest (2,247 ) Total $ 62,369 Lease cost for the three and nine months ended September 30, 2019 consisted of the following: Three months ended September 30, Nine months ended September 30, 2019 2019 (In thousands) Operating lease cost $ 4,551 $ 20,835 Operating lease cost - related party 5,610 16,830 Variable lease cost 105 1,065 Variable lease cost - related party 5,357 64,968 Short-term lease cost 224 407 Total lease cost (1) $ 15,847 $ 104,105 (1) The majority of the Company's total lease cost was capitalized to the full cost pool, and the remainder was included in general and administrative expenses in the accompanying consolidated statements of operations. Supplemental cash flow information for the nine months ended September 30, 2019 related to leases was as follows: Cash paid for amounts included in the measurement of lease liabilities (In thousands) Operating cash flows from operating leases $ 146 Investing cash flow from operating leases $ 18,998 Investing cash flow from operating leases - related party $ 78,518 The weighted-average remaining lease term as of September 30, 2019 was 1.82 years. The weighted-average discount rate used to determine the operating lease liability as of September 30, 2019 was 3.66%

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The dollar amounts and the effective tax rates in this note have been restated as a result of the matter described in Note 1. The Company records its quarterly tax provision based on an estimate of the annual effective tax rate expected to apply to continuing operations for the various jurisdictions in which it operates. The tax effects of certain items, such as tax rate changes, significant unusual or infrequent items, and certain changes in the assessment of the realizability of deferred taxes, are recognized as discrete items in the period in which they occur and are excluded from the estimated annual effective tax rate. The Company’s ability to utilize NOL carryforwards and other tax attributes to reduce future federal taxable income is subject to potential limitations under Internal Revenue Code Section 382 (“Section 382”) and its related tax regulations. The utilization of these attributes may be limited if certain ownership changes by 5% stockholders (as defined in Treasury regulations pursuant to Section 382) and the effects of stock issuances by the Company during any three-year period result in a cumulative change of more than 50% in the beneficial ownership of Gulfport. The Company updates its Section 382 analysis to determine if an ownership change has occurred at each reporting period. If it is determined that an ownership change has occurred under these rules, the Company would generally be subject to an annual limitation on the use of pre-ownership change NOL carryforwards and certain other losses and/or credits. In addition, certain future transactions regarding the Company's equity, including the cumulative effects of small transactions as well as transactions beyond the Company’s control, could cause an ownership change and therefore a potential limitation on the annual utilization of its deferred tax assets. For the three month period ended March 31, 2019, the Company maintained a full valuation allowance against its deferred tax assets based on its conclusion, considering all available evidence (both positive and negative), that it was more likely than not that the deferred tax assets would not be realized. A valuation allowance for deferred tax assets, including net operating losses, is recognized when it is more likely than not that some or all of the benefit from the deferred tax assets will not be realized. To assess that likelihood, the Company uses estimates and judgment regarding future taxable income, and considers the tax laws in the jurisdiction where such taxable income is generated, to determine whether a valuation allowance is required. Such evidence can include current financial position, results of operations, both actual and forecasted, the reversal of deferred tax liabilities and tax planning strategies as well as the current and forecasted business economics of the oil and gas industry. As of June 30, 2019, in part because in the current year the Company achieved more than three years of cumulative pretax income in the U.S. federal tax jurisdiction and the Company determined that an ownership change under Internal Revenue Code Section 382 did not occur that would further limit its ability to utilize net operating loss carryforwards, management determined that there was sufficient positive evidence to conclude that it is more likely than not that additional deferred taxes of $207.0 million are realizable. For the three and nine months ended September 30, 2019, the Company recognized $27.7 million and $207.0 million , respectively, as a discrete tax benefit. It therefore reduced the valuation allowance accordingly and maintains a valuation allowance of $5.0 million related to foreign tax credits, general business credits and net operating losses in jurisdictions for which it has determined that it is more likely than not that deferred tax assets would not be realized before expiration. As of each reporting date, management considers new evidence, both positive and negative, that could affect its view of the future realization of deferred tax assets. This assessment relies upon a number of areas of management’s judgment regarding forecast of results in subsequent years. Changes in those judgments could require the Company to establish a valuation allowance for currently recognized deferred tax assets in a subsequent reporting period. In addition, if the Company incurred an Internal Revenue Code Section 382 ownership change it would significantly limit the Company’s ability to utilize net operating loss carryforwards and other tax attributes. For the three and nine months ended September 30, 2019 , the Company's estimated annual effective tax rates were approximately 50.4% and 28.2% , respectively. The effective tax rate varies from the expected statutory tax rate of 21% primarily because of the release of the valuation allowance of $207.0 million for the nine months ended September 30, 2019. The Company also recognized tax expense of $1.6 million and $1.7 million for the three and nine months ended September 30, 2019 , respectively, related to equity compensation book amounts that exceed the tax deduction.

CONDENSED CONSOLIDATING FINANCI

CONDENSED CONSOLIDATING FINANCIAL INFORMATION	9 Months Ended
	Sep. 30, 2019
Condensed Financial Information Disclosure [Abstract]
CONDENSED CONSOLIDATING FINANCIAL INFORMATION	CONDENSED CONSOLIDATING FINANCIAL INFORMATION The 2023 Notes, the 2024 Notes, the 2025 Notes and the 2026 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 Notes are not guaranteed by Grizzly Holdings or Mule Sky LLC ("Mule Sky") (the “Non-Guarantors”). 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. Effective June 1, 2019, the Parent contributed interests in certain oil and gas assets and related liabilities to certain of the Guarantors. The following condensed consolidating balance sheets, statements of operations, statements of comprehensive income and statements of cash flows are provided for the Parent, the Guarantors and the Non-Guarantors 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-Guarantors. CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Assets Current assets: Cash and cash equivalents $ 6,279 $ 3,715 $ 130 $ — $ 10,124 Accounts receivable - oil and natural gas sales 857 111,800 — — 112,657 Accounts receivable - joint interest and other 6,909 34,418 — — 41,327 Accounts receivable - intercompany 953,446 625,306 — (1,578,752 ) — Prepaid expenses and other current assets 3,886 1,697 75 — 5,658 Short-term derivative instruments 134,571 — — — 134,571 Total current assets 1,105,948 776,936 205 (1,578,752 ) 304,337 Property and equipment: Oil and natural gas properties, full-cost accounting 1,312,715 9,239,581 146 (729 ) 10,551,713 Other property and equipment 92,163 751 3,319 — 96,233 Accumulated depletion, depreciation, amortization and impairment (1,416,248 ) (4,200,519 ) (221 ) — (5,616,988 ) Property and equipment, net (11,370 ) 5,039,813 3,244 (729 ) 5,030,958 Other assets: Equity investments and investments in subsidiaries 4,553,316 — 49,545 (4,528,899 ) 73,962 Long-term derivative instruments 23,419 — — — 23,419 Deferred tax asset 323,378 — — — 323,378 Inventories 94 6,928 — — 7,022 Operating lease assets 13,920 — — — 13,920 Operating lease assets - related parties 48,449 — — — 48,449 Other assets 11,333 320 — — 11,653 Total other assets 4,973,909 7,248 49,545 (4,528,899 ) 501,803 Total assets $ 6,068,487 $ 5,823,997 $ 52,994 $ (6,108,380 ) $ 5,837,098 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 69,863 $ 369,129 $ 27 $ — $ 439,019 Accounts payable - intercompany 660,364 914,401 3,987 (1,578,752 ) — Short-term derivative instruments 429 — — — 429 Current portion of operating lease liabilities 12,848 — — — 12,848 Current portion of operating lease liabilities - related parties 21,017 — — — 21,017 Current maturities of long-term debt 622 — — — 622 Total current liabilities 765,143 1,283,530 4,014 (1,578,752 ) 473,935 Long-term derivative instruments 72,040 — — — 72,040 Asset retirement obligation - long-term — 59,819 — — 59,819 Uncertain tax position liability 3,127 — — — 3,127 Non-current operating lease liabilities 1,072 — — — 1,072 Non-current operating lease liabilities - related parties 27,432 — — — 27,432 Long-term debt, net of current maturities 2,076,569 — — — 2,076,569 Total liabilities 2,945,383 1,343,349 4,014 (1,578,752 ) 2,713,994 Stockholders’ equity: Common stock 1,597 — — — 1,597 Paid-in capital 4,205,158 4,170,573 262,061 (4,432,634 ) 4,205,158 Accumulated other comprehensive loss (50,679 ) — (48,548 ) 48,548 (50,679 ) (Accumulated deficit) retained earnings (1,032,972 ) 310,075 (164,533 ) (145,542 ) (1,032,972 ) Total stockholders’ equity 3,123,104 4,480,648 48,980 (4,529,628 ) 3,123,104 Total liabilities and stockholders ’ equity $ 6,068,487 $ 5,823,997 $ 52,994 $ (6,108,380 ) $ 5,837,098 CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) December 31, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 25,585 $ 26,711 $ 1 $ — $ 52,297 Accounts receivable - oil and natural gas sales 146,075 64,125 — — 210,200 Accounts receivable - joint interest and other 16,212 6,285 — — 22,497 Accounts receivable - intercompany 671,633 319,464 — (991,097 ) — Prepaid expenses and other current assets 7,843 2,174 — — 10,017 Short-term derivative instruments 21,352 — — — 21,352 Total current assets 888,700 418,759 1 (991,097 ) 316,363 Property and equipment: Oil and natural gas properties, full-cost accounting, 7,044,550 2,983,015 — (729 ) 10,026,836 Other property and equipment 91,916 751 — — 92,667 Accumulated depletion, depreciation, amortization and impairment (4,640,059 ) (39 ) — — (4,640,098 ) Property and equipment, net 2,496,407 2,983,727 — (729 ) 5,479,405 Other assets: Equity investments and investments in subsidiaries 2,856,988 — 44,259 (2,665,126 ) 236,121 Inventories 4,210 1,134 — — 5,344 Other assets 12,624 1,178 — 1 13,803 Total other assets 2,873,822 2,312 44,259 (2,665,125 ) 255,268 Total assets $ 6,258,929 $ 3,404,798 $ 44,260 $ (3,656,951 ) $ 6,051,036 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 419,107 $ 99,273 $ — $ — $ 518,380 Accounts payable - intercompany 320,259 670,708 130 (991,097 ) — Short-term derivative instruments 20,401 — — — 20,401 Current maturities of long-term debt 651 — — — 651 Total current liabilities 760,418 769,981 130 (991,097 ) 539,432 Long-term derivative instruments 13,992 — — — 13,992 Asset retirement obligation - long-term 66,859 13,093 — — 79,952 Uncertain tax position liability 3,127 — — — 3,127 Long-term debt, net of current maturities 2,086,765 — — — 2,086,765 Total liabilities 2,931,161 783,074 130 (991,097 ) 2,723,268 Stockholders’ equity: Common stock 1,630 — — — 1,630 Paid-in capital 4,227,532 1,915,598 261,626 (2,177,224 ) 4,227,532 Accumulated other comprehensive loss (56,026 ) — (53,783 ) 53,783 (56,026 ) (Accumulated deficit) retained earnings (845,368 ) 706,126 (163,713 ) (542,413 ) (845,368 ) Total stockholders’ equity 3,327,768 2,621,724 44,130 (2,665,854 ) 3,327,768 Total liabilities and stockholders ’ equity $ 6,258,929 $ 3,404,798 $ 44,260 $ (3,656,951 ) $ 6,051,036 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Total revenues $ 27,358 $ 257,817 $ — $ — $ 285,175 Costs and expenses: Lease operating expenses (231 ) 22,704 — — 22,473 Production taxes 36 6,529 — — 6,565 Midstream gathering and processing expenses — 78,435 — — 78,435 Depreciation, depletion and amortization 2,686 160,418 166 — 163,270 Impairment of oil and natural gas properties — 571,442 — — 571,442 General and administrative expenses 27,218 (12,675 ) 116 — 14,659 Accretion expense — 747 — — 747 29,709 827,600 282 — 857,591 LOSS FROM OPERATIONS (2,351 ) (569,783 ) (282 ) — (572,416 ) OTHER EXPENSE (INCOME): Interest expense 35,105 (1,010 ) — — 34,095 Interest income (187 ) (151 ) — — (338 ) Gain on debt extinguishment (23,600 ) — — — (23,600 ) Loss from equity method investments and investments in subsidiaries 616,348 — 40 (573,306 ) 43,082 Other (income) expense (1,168 ) 3,362 — 1,000 3,194 626,498 2,201 40 (572,306 ) 56,433 LOSS BEFORE INCOME TAXES (628,849 ) (571,984 ) (322 ) 572,306 (628,849 ) INCOME TAX BENEFIT (144,047 ) — — — (144,047 ) NET LOSS $ (484,802 ) $ (571,984 ) $ (322 ) $ 572,306 $ (484,802 ) CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 235,683 $ 125,279 $ — $ — $ 360,962 Costs and expenses: Lease operating expenses 16,502 5,823 — — 22,325 Production taxes 4,505 4,843 — — 9,348 Midstream gathering and processing expenses 54,397 24,516 — — 78,913 Depreciation, depletion and amortization 119,914 1 — — 119,915 General and administrative expenses 16,314 (467 ) 1 — 15,848 Accretion expense 812 225 — — 1,037 212,444 34,941 1 — 247,386 INCOME (LOSS) FROM OPERATIONS 23,239 90,338 (1 ) — 113,576 OTHER (INCOME) EXPENSE: Interest expense 34,254 (1,001 ) — — 33,253 Interest income (86 ) (6 ) — — (92 ) Gain on sale of equity method investments (2,733 ) — — — (2,733 ) (Income) loss from equity method investments and investments in subsidiaries (104,226 ) (1 ) 275 91,094 (12,858 ) Other expense (income) 880 (24 ) — — 856 (71,911 ) (1,032 ) 275 91,094 18,426 INCOME (LOSS) BEFORE INCOME TAXES 95,150 91,370 (276 ) (91,094 ) 95,150 INCOME TAX BENEFIT — — — — — NET INCOME (LOSS) $ 95,150 $ 91,370 $ (276 ) $ (91,094 ) $ 95,150 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Nine months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Total revenues $ 493,895 $ 570,852 $ — $ — $ 1,064,747 Costs and expenses: Lease operating expenses 26,918 37,750 — — 64,668 Production taxes 6,117 16,467 — — 22,584 Midstream gathering and processing expenses 71,420 149,312 — — 220,732 Depreciation, depletion, and amortization 201,250 205,183 221 — 406,654 Impairment of oil and gas properties — 571,442 — — 571,442 General and administrative expenses 56,195 (16,933 ) 220 — 39,482 Accretion expense 1,389 1,784 — — 3,173 363,289 965,005 441 — 1,328,735 INCOME (LOSS) FROM OPERATIONS 130,606 (394,153 ) (441 ) — (263,988 ) OTHER EXPENSE (INCOME): Interest expense 105,364 (2,269 ) — — 103,095 Interest income (454 ) (195 ) — — (649 ) Gain on debt extinguishment (23,600 ) — — — (23,600 ) Loss from equity method investments and investments in subsidiaries 560,883 — 379 (396,871 ) 164,391 Other (income) expense (605 ) 3,362 — 1,000 3,757 641,588 898 379 (395,871 ) 246,994 LOSS BEFORE INCOME TAXES (510,982 ) (395,051 ) (820 ) 395,871 (510,982 ) INCOME TAX BENEFIT (323,378 ) — — — (323,378 ) NET LOSS $ (187,604 ) $ (395,051 ) $ (820 ) $ 395,871 $ (187,604 ) CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Nine months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 596,018 $ 343,076 $ — $ — $ 939,094 Costs and expenses: Lease operating expenses 46,926 17,217 — — 64,143 Production taxes 13,309 10,552 — — 23,861 Midstream gathering and processing expenses 152,605 61,941 — — 214,546 Depreciation, depletion, and amortization 352,846 2 — — 352,848 General and administrative expenses 45,100 (2,148 ) 3 — 42,955 Accretion expense 2,397 659 — — 3,056 613,183 88,223 3 — 701,409 (LOSS) INCOME FROM OPERATIONS (17,165 ) 254,853 (3 ) — 237,685 OTHER (INCOME) EXPENSE: Interest expense 103,310 (2,388 ) — — 100,922 Interest income (144 ) (18 ) — — (162 ) Gain on sale of equity method investments (28,349 ) (96,419 ) — — (124,768 ) (Income) loss from equity method investments and investments in subsidiaries (387,991 ) (694 ) 833 352,570 (35,282 ) Other (income) expense (481 ) (34 ) — 1,000 485 (313,655 ) (99,553 ) 833 353,570 (58,805 ) INCOME (LOSS) BEFORE INCOME TAXES 296,490 354,406 (836 ) (353,570 ) 296,490 INCOME TAX BENEFIT (69 ) — — — (69 ) NET INCOME (LOSS) $ 296,559 $ 354,406 $ (836 ) $ (353,570 ) $ 296,559 CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Amounts in thousands) Three months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Net loss $ (484,802 ) $ (571,984 ) $ (322 ) $ 572,306 $ (484,802 ) Foreign currency translation adjustment (2,064 ) (43 ) (2,021 ) 2,064 (2,064 ) Other comprehensive loss (2,064 ) (43 ) (2,021 ) 2,064 (2,064 ) Comprehensive loss $ (486,866 ) $ (572,027 ) $ (2,343 ) $ 574,370 $ (486,866 ) Three months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 95,150 $ 91,370 $ (276 ) $ (91,094 ) $ 95,150 Foreign currency translation adjustment 3,052 103 2,949 (3,052 ) 3,052 Other comprehensive income 3,052 103 2,949 (3,052 ) 3,052 Comprehensive income $ 98,202 $ 91,473 $ 2,673 $ (94,146 ) $ 98,202 Nine months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Net loss $ (187,604 ) $ (395,051 ) $ (820 ) $ 395,871 $ (187,604 ) Foreign currency translation adjustment 5,347 112 5,235 (5,347 ) 5,347 Other comprehensive income 5,347 112 5,235 (5,347 ) 5,347 Comprehensive (loss) income $ (182,257 ) $ (394,939 ) $ 4,415 $ 390,524 $ (182,257 ) Nine months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 296,559 $ 354,406 $ (836 ) $ (353,570 ) $ 296,559 Foreign currency translation adjustment (5,815 ) (70 ) (5,745 ) 5,815 (5,815 ) Other comprehensive loss (5,815 ) (70 ) (5,745 ) 5,815 (5,815 ) Comprehensive income (loss) $ 290,744 $ 354,336 $ (6,581 ) $ (347,755 ) $ 290,744 CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Amounts in thousands) Nine months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Net cash (used in) provided by operating activities $ (7,604 ) $ 621,511 $ 3,445 $ 3 $ 617,355 Net cash provided by (used in) investing activities 9,178 (644,507 ) (3,751 ) 432 (638,648 ) Net cash (used in) provided by financing activities (20,880 ) — 435 (435 ) (20,880 ) Net (decrease) increase in cash, cash equivalents and restricted cash (19,306 ) (22,996 ) 129 — (42,173 ) Cash, cash equivalents and restricted cash at beginning of period 25,585 26,711 1 — 52,297 Cash, cash equivalents and restricted cash at end of period $ 6,279 $ 3,715 $ 130 $ — $ 10,124 Nine months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 427,351 $ 203,446 $ (1 ) $ 1 $ 630,797 Net cash (used in) provided by investing activities (354,848 ) (199,738 ) (2,318 ) 2,318 (554,586 ) Net cash (used in) provided by financing activities (51,197 ) — 2,319 (2,319 ) (51,197 ) Net increase in cash, cash equivalents and restricted cash 21,306 3,708 — — 25,014 Cash, cash equivalents and restricted cash at beginning of period 67,908 31,649 — — 99,557 Cash, cash equivalents and restricted cash at end of period $ 89,214 $ 35,357 $ — $ — $ 124,571

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS Derivatives In October 2019, the Company early terminated some of its fixed price swaps for oil and natural gas scheduled to settle during the fourth quarter of 2019 covering approximately 1,000 BBls of oil per day and 120,000 MMBtu of natural gas per day. The value of these early terminations was used to enhance the fixed price for new natural gas swaps for 2020 covering approximately 28,000 MMBtu of natural gas per day at a weighted average price of $2.85

BASIS OF PRESENTATION AND SUM_2

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation These consolidated financial statements have been prepared by Gulfport Energy Corporation (the “Company” or “Gulfport”) without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”), and reflect all adjustments that, in the opinion of management, are necessary for a fair presentation of the results for the interim periods reported in all material respects, on a basis consistent with the annual audited consolidated financial statements. All such adjustments are of a normal, recurring nature. Certain information, accounting policies, and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles ("GAAP") have been omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. These consolidated financial statements should be read in conjunction with the consolidated financial statements and the summary of significant accounting policies and notes included in the Company’s most recent annual report on Form 10-K. Results for the three and nine months ended September 30, 2019
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2016 , the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02 , Leases (Topic 842) . The standard supersedes the previous lease guidance by requiring lessees to recognize a right-to-use asset and lease liability on the balance sheet for all leases with lease terms of greater than one year while maintaining substantially similar classifications for financing and operating leases. Subsequent to ASU 2016-02, the FASB issued several related ASU’s to clarify the application of the lease standard. The Company adopted the new standard as of January 1, 2019 on a prospective basis using the simplified transition method permitted by ASU 2018-11, Leases (Topic 842): Targeted Improvements. The comparative information has not been restated and continues to be reported under the historic accounting standards in effect for those periods. See Note 13 for further discussion of the lease standard. 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. Additionally, in May 2019 , the FASB issued ASU No. 2019-05 , Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief . The amendments in this update allow preparers to irrevocably elect the fair value option, on an instrument-by-instrument basis, for eligible financial assets measured at amortized cost basis upon adoption of 2016-13 . The guidance is effective for periods after December 15, 2019, with early adoption permitted. The Company is in the process of designing processes and controls needed to comply with the requirements of the new standard. Although the standard will have an impact, the Company does not currently anticipate the ASU to have a material effect on its consolidated financial statements and related disclosures. In August 2018 , the FASB issued ASU No. 2018-13 , Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement , which removes, modifies, and adds certain disclosure requirements on fair value measurements. The amendment will be effective for reporting periods beginning after December 15, 2019 , and early adoption is permitted. The Company does not anticipate the new standard to have a material effect on its consolidated financial statements and related disclosures. In August 2018 , the FASB also issued ASU No. 2018-15 , Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , which aligns the accounting for costs associated with implementing a cloud computing arrangement in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software. The amendment will be effective for reporting periods beginning after December 15, 2019 , and early adoption is permitted. The Company does not anticipate the new standard to have a material effect on its consolidated financial statements and related disclosures. In November 2018 , the FASB issued ASU No. 2018-18 , Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606 , which provides guidance on how to assess whether certain transactions between participants in a collaborative arrangement should be accounted for within the ASU No. 2014-09 revenue recognition standard discussed above. The amendment will be effective for reporting periods beginning after December 15, 2019 , and early adoption is permitted. The Company does not anticipate the new standard to have a material effect on its consolidated financial statements and related disclosures. In July 2019, the FASB issued ASU No. 2019-07 , Codification Updates to SEC Sections, Amendments to SEC Paragraphs Pursuant to SEC Final Rule Releases No. 33-10532, Disclosure Update and Simplification, and Nos. 33-10231 and 33-10442, Investment Company Reporting Modernization, and Miscellaneous Updates . This ASU amends various SEC sections within the FASB Codification to align with the updated requirements of certain SEC final rules and includes miscellaneous updates to agree the language in the Codification to the electronic Code of Federal Regulations. ASU No. 2019-07

BASIS OF PRESENTATION AND SUM_3

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Schedule of Adjustments	The following tables present the effect of the error correction discussed above on all affected line items of our previously issued consolidated balance sheets as of September 30, 2019 , consolidated statements of operations for the three and nine months ended September 30, 2019 , consolidated statements of comprehensive income for the three and nine months ended September 30, 2019 , consolidated statements of stockholders' equity for the three months ended September 30, 2019 and the consolidated statements of cash flows for the nine months ended September 30, 2019 . Consolidated Balance Sheets September 30, 2019 As Reported Adjustments As Restated (In thousands) Accumulated depletion, depreciation, amortization and impairment (5,063,413 ) (553,575 ) (5,616,988 ) Property and equipment, net (1) 5,584,533 (553,575 ) 5,030,958 Deferred tax asset 205,853 117,525 323,378 Total other assets 384,278 117,525 501,803 Total assets $ 6,273,148 (436,050 ) $ 5,837,098 Accumulated deficit (596,922 ) (436,050 ) (1,032,972 ) Total stockholders’ equity 3,559,154 (436,050 ) 3,123,104 Total liabilities and stockholders’ equity $ 6,273,148 (436,050 ) $ 5,837,098 (1) Amount excluded from amortization in 2019 $ 2,814,334 (553,575 ) $ 2,260,759 Consolidated Statements of Operations Three Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Depreciation, depletion and amortization $ 145,490 17,780 $ 163,270 Impairment of oil and natural gas properties 35,647 535,795 571,442 Total Costs and Expenses 304,016 553,575 857,591 (LOSS) INCOME FROM OPERATIONS (18,841 ) (553,575 ) (572,416 ) (LOSS) INCOME BEFORE INCOME TAXES (75,274 ) (553,575 ) (628,849 ) INCOME TAX BENEFIT (26,522 ) (117,525 ) (144,047 ) NET (LOSS) INCOME $ (48,752 ) (436,050 ) $ (484,802 ) NET (LOSS) INCOME PER COMMON SHARE: Basic $ (0.31 ) $ (2.73 ) $ (3.04 ) Diluted $ (0.31 ) $ (2.73 ) $ (3.04 ) Nine Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands, except share data) Depreciation, depletion and amortization $ 388,874 17,780 $ 406,654 Impairment of oil and natural gas properties 35,647 535,795 571,442 Total Costs and Expenses 775,160 553,575 1,328,735 (LOSS) INCOME FROM OPERATIONS 289,587 (553,575 ) (263,988 ) (LOSS) INCOME BEFORE INCOME TAXES 42,593 (553,575 ) (510,982 ) INCOME TAX BENEFIT (205,853 ) (117,525 ) (323,378 ) NET (LOSS) INCOME $ 248,446 (436,050 ) $ (187,604 ) NET (LOSS) INCOME PER COMMON SHARE: Basic $ 1.55 $ (2.72 ) $ (1.17 ) Diluted $ 1.51 $ (2.68 ) $ (1.17 ) Weighted average common shares outstanding—Diluted 164,820,002 (4,266,206 ) 160,553,796 Consolidated Statements of Comprehensive Income Three Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Net (loss) income $ (48,752 ) (436,050 ) $ (484,802 ) Comprehensive (loss) income $ (50,816 ) (436,050 ) $ (486,866 ) Nine Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Net (loss) income $ 248,446 (436,050 ) $ (187,604 ) Comprehensive (loss) income $ 253,793 (436,050 ) $ (182,257 ) Consolidated Statements of Stockholders' Equity Accumulated Deficit As Reported Adjustments As Restated (In thousands) Net loss $ (48,752 ) (436,050 ) $ (484,802 ) Balance at September 30, 2019 $ (596,922 ) (436,050 ) $ (1,032,972 ) Total Stockholders' Equity As Reported Adjustments As Restated (In thousands) Net loss $ (48,752 ) (436,050 ) $ (484,802 ) Balance at September 30, 2019 $ 3,559,154 (436,050 ) $ 3,123,104 Consolidated Statements of Cash Flows Nine Months Ended September 30, 2019 As Reported Adjustments As Restated (In thousands) Cash flows from operating activities: Net (loss) income $ 248,446 (436,050 ) $ (187,604 ) Adjustments to reconcile net (loss) income to net cash provided by operating activities: Depletion, depreciation and amortization 388,874 17,780 406,654 Impairment of oil and natural gas properties 35,647 535,795 571,442 Deferred income tax benefit (205,853 ) (117,525 ) (323,378 )

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	9 Months Ended
	Sep. 30, 2019
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 September 30, 2019 and December 31, 2018 are as follows: September 30, 2019 December 31, 2018 (In thousands) As Restated Oil and natural gas properties $ 10,551,713 $ 10,026,836 Other depreciable property and equipment 90,712 87,146 Land 5,521 5,521 Total property and equipment 10,647,946 10,119,503 Accumulated depletion, depreciation, amortization and impairment (5,616,988 ) (4,640,098 ) Property and equipment, net $ 5,030,958 $ 5,479,405
Schedule of non-producing properties excluded from amortization by area	The following table summarizes the Company’s unproved properties excluded from amortization by area at September 30, 2019 : September 30, 2019 (In thousands) As Restated Utica $ 1,112,148 MidContinent 1,148,271 Other 340 $ 2,260,759
Schedule of asset retirement obligation	A reconciliation of the Company’s asset retirement obligation for the nine months ended September 30, 2019 and 2018 is as follows: September 30, 2019 September 30, 2018 (In thousands) Asset retirement obligation, beginning of period $ 79,952 $ 75,100 Liabilities incurred 5,769 1,468 Liabilities settled (117 ) (719 ) Liabilities removed due to divestitures (30,035 ) — Accretion expense 3,173 3,056 Revisions in estimated cash flows 1,077 (374 ) Asset retirement obligation as of end of period 59,819 78,531 Less current portion — 120 Asset retirement obligation, long-term $ 59,819 $ 78,411

EQUITY INVESMENTS (Tables)

EQUITY INVESMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Schedule of equity method investments	Investments accounted for by the equity method consist of the following as of September 30, 2019 and December 31, 2018 : Carrying value Loss (income) from equity method investments Approximate ownership % September 30, 2019 December 31, 2018 Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (In thousands) Investment in Tatex Thailand II, LLC 23.5 % $ — $ — $ — $ (137 ) $ (2,085 ) $ (241 ) Investment in Grizzly Oil Sands ULC 24.9999 % 49,546 44,259 41 275 380 833 Investment in Timber Wolf Terminals LLC (1) — % — — — — — 536 Investment in Windsor Midstream LLC 22.5 % 39 39 — — — (9 ) Investment in Mammoth Energy Services, Inc. 21.8 % 24,377 191,823 43,041 (12,996 ) 166,096 (35,708 ) Investment in Strike Force Midstream LLC (2) — % — — — — — (693 ) $ 73,962 $ 236,121 $ 43,082 $ (12,858 ) $ 164,391 $ (35,282 ) (1) On June 5, 2018, the Company received its final distribution from Timber Wolf Terminals LLC ("Timber Wolf"). See below under Timber Wolf Terminals LLC for information regarding the subsequent dissolution of Timber Wolf. (2) On May 1, 2018, the Company sold its 25% interest in Strike Force Midstream LLC ("Strike Force") to EQT Midstream Partners, LP. See below under Strike Force Midstream LLC for information regarding this transaction.
Schedule of equity investments - balance sheet	The tables below summarize financial information for the Company’s equity investments as of September 30, 2019 and December 31, 2018 . Summarized balance sheet information: September 30, 2019 December 31, 2018 (In thousands) Current assets $ 427,643 $ 471,733 Noncurrent assets $ 1,309,729 $ 1,302,488 Current liabilities $ 130,465 $ 239,975 Noncurrent liabilities $ 176,145 $ 94,575
Schedule of equity investments - income statement	Summarized results of operations: Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (In thousands) Gross revenue $ 113,417 $ 384,043 $ 557,375 $ 1,451,580 Net (loss) income $ (35,730 ) $ 68,414 $ (15,046 ) $ 181,884

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	9 Months Ended
	Sep. 30, 2019
Long-term Debt, Unclassified [Abstract]
Schedule of long-term debt	Long-term debt consisted of the following items as of September 30, 2019 and December 31, 2018 : September 30, 2019 December 31, 2018 (In thousands) Revolving credit agreement (1) $ 135,000 $ 45,000 6.625% senior unsecured notes due 2023 340,000 350,000 6.000% senior unsecured notes due 2024 630,796 650,000 6.375% senior unsecured notes due 2025 577,268 600,000 6.375% senior unsecured notes due 2026 397,529 450,000 Net unamortized debt issuance costs (2) (26,052 ) (30,733 ) Construction loan 22,650 23,149 Less: current maturities of long term debt (622 ) (651 ) Debt reflected as long term $ 2,076,569 $ 2,086,765 (1) The Company has entered into a senior secured revolving credit facility, as amended (the "revolving credit facility"), with The Bank of Nova Scotia, as the lead arranger and administrative agent and other lenders. On June 3, 2019, the Company further amended its revolving credit facility to, among other things, allow the Company to designate certain of its subsidiaries as unrestricted subsidiaries and to include LIBOR replacement provisions. Additionally, the borrowing base was reaffirmed at $1.4 billion , and the Company’s elected commitment amount remained at $1.0 billion . As of September 30, 2019 , $135.0 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 $248.6 million letters of credit, was $616.4 million . The Company’s wholly owned subsidiaries have guaranteed the obligations of the Company under the revolving credit facility. At September 30, 2019 , amounts borrowed under the revolving credit facility bore interest at a weighted average rate of 3.52% . The Company was in compliance with its financial covenants under the revolving credit facility at September 30, 2019 . (2) Loan issuance costs related to the 6.625% Senior Notes due 2023 (the "2023 Notes"), the 6.000% Senior Notes due 2024 (the "2024 Notes"), the 6.375% Senior Notes due 2025 (the "2025 Notes") and the 6.375% Senior Notes due 2026 (the "2026 Notes") (collectively the “Notes”) have been presented as a reduction to the principal amount of the Notes. At September 30, 2019 , total unamortized debt issuance costs were $3.6 million for the 2023 Notes, $7.5 million for the 2024 Notes, $10.8 million for the 2025 Notes and $4.0 million for the 2026 Notes. In addition, loan commitment fee costs for the Company's construction loan agreement were $0.1 million at September 30, 2019 .

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
Schedule of restricted stock activity	The following table summarizes restricted stock unit activity for the nine months ended September 30, 2019 : Number of Unvested Restricted Stock Units Weighted Average Grant Date Fair Value Number of Unvested Performance Vesting Restricted Stock Units Weighted Average Grant Date Fair Value Unvested shares as of January 1, 2019 1,535,811 $ 11.57 $ — $ — Granted 4,011,073 3.74 2,009,144 2.85 Vested (674,374 ) 12.86 — — Forfeited (289,610 ) 7.83 (112,742 ) 1.98 Unvested shares as of September 30, 2019 4,582,900 $ 4.76 1,896,402 $ 2.91

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of earnings per share	Reconciliations of the components of basic and diluted net income per common share are presented in the tables below: Three months ended September 30, 2019 2018 Loss Shares Per Share Income Shares Per Share (In thousands, except share data) Basic: Net (loss) income (as restated) $ (484,802 ) 159,548,477 $ (3.04 ) $ 95,150 173,057,538 $ 0.55 Effect of dilutive securities: Stock options and awards — — — 247,376 Diluted: Net (loss) income (as restated) $ (484,802 ) 159,548,477 $ (3.04 ) $ 95,150 173,304,914 $ 0.55 Nine months ended September 30, 2019 2018 Income Shares Per Income Shares Per (In thousands, except share data) Basic: Net (loss)income (as restated) $ (187,604 ) 160,553,796 $ (1.17 ) $ 296,559 175,776,312 $ 1.69 Effect of dilutive securities: Stock options and awards (as restated) — — — 664,149 Diluted: Net (loss) income (as restated) $ (187,604 ) 160,553,796 $ (1.17 ) $ 296,559 176,440,461 $ 1.68

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of firm transportation commitments	The table below presents the firm sales commitments by year: (MMBtu per day) Remaining 2019 424,000 2020 314,000 2021 192,000 2022 70,000 2023 17,000 Thereafter — Total 1,017,000
Schedule of other commitments	The table below presents the firm transportation commitments by year: (In thousands) Remaining 2019 $ 65,763 2020 287,627 2021 286,665 2022 286,665 2023 282,981 Thereafter 2,410,866 Total $ 3,620,567 Future minimum commitments under this agreement at September 30, 2019 are: (In thousands) Remaining 2019 $ 6,000 2020 24,000 2021 24,000 Total $ 54,000

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Schedule of open fixed price swap positions and natural gas basis swap positions	Below is a summary of the Company’s open fixed price swap positions as of September 30, 2019 . Location Daily Volume (MMBtu/day) Weighted Remaining 2019 NYMEX Henry Hub 1,380,000 $ 2.81 2020 NYMEX Henry Hub 519,000 $ 2.88 Location Daily Volume Weighted Remaining 2019 NYMEX WTI 6,000 $ 60.81 2020 NYMEX WTI 6,000 $ 59.82 Location Daily Volume Weighted Remaining 2019 Mont Belvieu C2 1,000 $ 18.48 Remaining 2019 Mont Belvieu C3 4,000 $ 29.02 Remaining 2019 Mont Belvieu C5 1,000 $ 53.71 The Company sold call options in exchange for a premium, and used the associated premiums to enhance the fixed price for a portion of the fixed price natural gas swaps primarily for 2020 listed above. Each call option has an established ceiling price. When the referenced settlement price is above the price ceiling established by these 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 2019 NYMEX Henry Hub 30,000 $ 3.10 2022 NYMEX Henry Hub 628,000 $ 2.90 2023 NYMEX Henry Hub 628,000 $ 2.90 September 30, 2019 , the Company had the following natural gas basis swap positions open: Gulfport Pays Gulfport Receives Daily Volume (MMBtu/day) Weighted Average Fixed Spread Remaining 2019 Transco Zone 4 NYMEX Plus Fixed Spread 60,000 $ (0.05 ) 2020 Transco Zone 4 NYMEX Plus Fixed Spread 60,000 $ (0.05 ) 2020 Fixed Spread ONEOK Minus NYMEX 10,000 $ (0.54 )
Schedule of purchase and sale agreement for sale of the company's non-core assets	The purchase and sale agreement for the sale of the Company's non-core assets located in the WCBB and Hackberry fields of Louisiana included a contingent consideration arrangement that entitles the Company to receive bonus payments if commodity prices exceed specified thresholds. The calculated fair value of this contingent payment arrangement was approximately $1.1 million as of the closing date of the divestiture. See below for threshold and potential payment amounts. Period Threshold (1) Payment to be received (2) July 2020 - June 2021 Greater than or equal to $60.65 $ 150,000 Between $52.62 - $60.65 Calculated Value (3) Less than or equal to $52.62 $ — (1) Based on the "WTI NYMEX + Argus LLS Differential," as published by Argus Media. (2) Payment will be assessed monthly from July 2020 through June 2021. If threshold is met, payment shall be received within five business days after the end of each calendar month. (3) If average daily price, as defined in (1), is greater than $52.62 but less than $60.65, payment received will be $150,000 multiplied by a fraction, the numerator of which is the amount determined by subtracting $52.62 from such average daily price, and the denominator of which is $8.03.
Schedule of derivative instruments in balance sheet	The following table presents the fair value of the Company’s derivative instruments on a gross basis at September 30, 2019 and December 31, 2018 : September 30, 2019 December 31, 2018 (In thousands) Commodity derivative instruments $ 134,511 $ 21,352 Contingent consideration arrangement 60 — Total short-term derivative instruments - asset $ 134,571 $ 21,352 Commodity derivative instruments $ 23,375 $ — Contingent consideration arrangement 44 — Total long-term derivative instruments - asset $ 23,419 $ — Total short-term derivative instruments - liability $ 429 $ 20,401 Total long-term derivative instruments - liability $ 72,040 $ 13,992
Schedule of net gain (loss) on derivatives	The following table presents the gain and loss recognized in net gain (loss) on natural gas, oil and NGLs derivatives in the accompanying consolidated statements of operations for the three and nine months ended September 30, 2019 and 2018 . Net gain (loss) on derivative instruments Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (In thousands) Natural gas derivatives $ 11,731 $ 14,101 $ 147,774 $ (26,789 ) Oil derivatives 12,736 (11,610 ) 24,153 (45,176 ) NGLs derivatives 3,641 (12,154 ) 7,276 (24,772 ) Contingent consideration arrangement (1,034 ) — (1,034 ) — Total $ 27,074 $ (9,663 ) $ 178,169 $ (96,737 )
Schedule of 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 September 30, 2019 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 157,990 $ (72,469 ) $ 85,521 Derivative liabilities $ (72,469 ) $ 72,469 $ — As of December 31, 2018 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 21,352 $ (19,289 ) $ 2,063 Derivative liabilities $ (34,393 ) $ 19,289 $ (15,104 )
Schedule of 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 September 30, 2019 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 157,990 $ (72,469 ) $ 85,521 Derivative liabilities $ (72,469 ) $ 72,469 $ — As of December 31, 2018 Gross Assets (Liabilities) Gross Amounts Presented in the Subject to Master Net Consolidated Balance Sheets Netting Agreements Amount (In thousands) Derivative assets $ 21,352 $ (19,289 ) $ 2,063 Derivative liabilities $ (34,393 ) $ 19,289 $ (15,104 )

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of financial and non-financial assets and liabilities by valuation level	The following tables summarize the Company’s financial and non-financial assets and liabilities by valuation level as of September 30, 2019 and December 31, 2018 : September 30, 2019 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 157,990 $ — Liabilities: Derivative Instruments $ — $ 72,469 $ — December 31, 2018 Level 1 Level 2 Level 3 (In thousands) Assets: Derivative Instruments $ — $ 21,352 $ — Liabilities: Derivative Instruments $ — $ 34,393 $ —

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Schedule of operating lease liability	Maturities of operating lease liabilities as of September 30, 2019 were as follows: (In thousands) Remaining 2019 $ 10,190 2020 31,460 2021 22,731 2022 115 2023 90 Thereafter 30 Total lease payments $ 64,616 Less: Imputed interest (2,247 ) Total $ 62,369
Schedule of lease cost	Lease cost for the three and nine months ended September 30, 2019 consisted of the following: Three months ended September 30, Nine months ended September 30, 2019 2019 (In thousands) Operating lease cost $ 4,551 $ 20,835 Operating lease cost - related party 5,610 16,830 Variable lease cost 105 1,065 Variable lease cost - related party 5,357 64,968 Short-term lease cost 224 407 Total lease cost (1) $ 15,847 $ 104,105 (1) The majority of the Company's total lease cost was capitalized to the full cost pool, and the remainder was included in general and administrative expenses in the accompanying consolidated statements of operations. Supplemental cash flow information for the nine months ended September 30, 2019 related to leases was as follows: Cash paid for amounts included in the measurement of lease liabilities (In thousands) Operating cash flows from operating leases $ 146 Investing cash flow from operating leases $ 18,998 Investing cash flow from operating leases - related party $ 78,518

CONDENSED CONSOLIDATING FINAN_2

CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2019
Condensed Financial Information Disclosure [Abstract]
CONDENSED CONSOLIDATING BALANCE SHEETS	CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Assets Current assets: Cash and cash equivalents $ 6,279 $ 3,715 $ 130 $ — $ 10,124 Accounts receivable - oil and natural gas sales 857 111,800 — — 112,657 Accounts receivable - joint interest and other 6,909 34,418 — — 41,327 Accounts receivable - intercompany 953,446 625,306 — (1,578,752 ) — Prepaid expenses and other current assets 3,886 1,697 75 — 5,658 Short-term derivative instruments 134,571 — — — 134,571 Total current assets 1,105,948 776,936 205 (1,578,752 ) 304,337 Property and equipment: Oil and natural gas properties, full-cost accounting 1,312,715 9,239,581 146 (729 ) 10,551,713 Other property and equipment 92,163 751 3,319 — 96,233 Accumulated depletion, depreciation, amortization and impairment (1,416,248 ) (4,200,519 ) (221 ) — (5,616,988 ) Property and equipment, net (11,370 ) 5,039,813 3,244 (729 ) 5,030,958 Other assets: Equity investments and investments in subsidiaries 4,553,316 — 49,545 (4,528,899 ) 73,962 Long-term derivative instruments 23,419 — — — 23,419 Deferred tax asset 323,378 — — — 323,378 Inventories 94 6,928 — — 7,022 Operating lease assets 13,920 — — — 13,920 Operating lease assets - related parties 48,449 — — — 48,449 Other assets 11,333 320 — — 11,653 Total other assets 4,973,909 7,248 49,545 (4,528,899 ) 501,803 Total assets $ 6,068,487 $ 5,823,997 $ 52,994 $ (6,108,380 ) $ 5,837,098 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 69,863 $ 369,129 $ 27 $ — $ 439,019 Accounts payable - intercompany 660,364 914,401 3,987 (1,578,752 ) — Short-term derivative instruments 429 — — — 429 Current portion of operating lease liabilities 12,848 — — — 12,848 Current portion of operating lease liabilities - related parties 21,017 — — — 21,017 Current maturities of long-term debt 622 — — — 622 Total current liabilities 765,143 1,283,530 4,014 (1,578,752 ) 473,935 Long-term derivative instruments 72,040 — — — 72,040 Asset retirement obligation - long-term — 59,819 — — 59,819 Uncertain tax position liability 3,127 — — — 3,127 Non-current operating lease liabilities 1,072 — — — 1,072 Non-current operating lease liabilities - related parties 27,432 — — — 27,432 Long-term debt, net of current maturities 2,076,569 — — — 2,076,569 Total liabilities 2,945,383 1,343,349 4,014 (1,578,752 ) 2,713,994 Stockholders’ equity: Common stock 1,597 — — — 1,597 Paid-in capital 4,205,158 4,170,573 262,061 (4,432,634 ) 4,205,158 Accumulated other comprehensive loss (50,679 ) — (48,548 ) 48,548 (50,679 ) (Accumulated deficit) retained earnings (1,032,972 ) 310,075 (164,533 ) (145,542 ) (1,032,972 ) Total stockholders’ equity 3,123,104 4,480,648 48,980 (4,529,628 ) 3,123,104 Total liabilities and stockholders ’ equity $ 6,068,487 $ 5,823,997 $ 52,994 $ (6,108,380 ) $ 5,837,098 CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) December 31, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 25,585 $ 26,711 $ 1 $ — $ 52,297 Accounts receivable - oil and natural gas sales 146,075 64,125 — — 210,200 Accounts receivable - joint interest and other 16,212 6,285 — — 22,497 Accounts receivable - intercompany 671,633 319,464 — (991,097 ) — Prepaid expenses and other current assets 7,843 2,174 — — 10,017 Short-term derivative instruments 21,352 — — — 21,352 Total current assets 888,700 418,759 1 (991,097 ) 316,363 Property and equipment: Oil and natural gas properties, full-cost accounting, 7,044,550 2,983,015 — (729 ) 10,026,836 Other property and equipment 91,916 751 — — 92,667 Accumulated depletion, depreciation, amortization and impairment (4,640,059 ) (39 ) — — (4,640,098 ) Property and equipment, net 2,496,407 2,983,727 — (729 ) 5,479,405 Other assets: Equity investments and investments in subsidiaries 2,856,988 — 44,259 (2,665,126 ) 236,121 Inventories 4,210 1,134 — — 5,344 Other assets 12,624 1,178 — 1 13,803 Total other assets 2,873,822 2,312 44,259 (2,665,125 ) 255,268 Total assets $ 6,258,929 $ 3,404,798 $ 44,260 $ (3,656,951 ) $ 6,051,036 Liabilities and Stockholders ’ Equity Current liabilities: Accounts payable and accrued liabilities $ 419,107 $ 99,273 $ — $ — $ 518,380 Accounts payable - intercompany 320,259 670,708 130 (991,097 ) — Short-term derivative instruments 20,401 — — — 20,401 Current maturities of long-term debt 651 — — — 651 Total current liabilities 760,418 769,981 130 (991,097 ) 539,432 Long-term derivative instruments 13,992 — — — 13,992 Asset retirement obligation - long-term 66,859 13,093 — — 79,952 Uncertain tax position liability 3,127 — — — 3,127 Long-term debt, net of current maturities 2,086,765 — — — 2,086,765 Total liabilities 2,931,161 783,074 130 (991,097 ) 2,723,268 Stockholders’ equity: Common stock 1,630 — — — 1,630 Paid-in capital 4,227,532 1,915,598 261,626 (2,177,224 ) 4,227,532 Accumulated other comprehensive loss (56,026 ) — (53,783 ) 53,783 (56,026 ) (Accumulated deficit) retained earnings (845,368 ) 706,126 (163,713 ) (542,413 ) (845,368 ) Total stockholders’ equity 3,327,768 2,621,724 44,130 (2,665,854 ) 3,327,768 Total liabilities and stockholders ’ equity $ 6,258,929 $ 3,404,798 $ 44,260 $ (3,656,951 ) $ 6,051,036
CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS	CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Total revenues $ 27,358 $ 257,817 $ — $ — $ 285,175 Costs and expenses: Lease operating expenses (231 ) 22,704 — — 22,473 Production taxes 36 6,529 — — 6,565 Midstream gathering and processing expenses — 78,435 — — 78,435 Depreciation, depletion and amortization 2,686 160,418 166 — 163,270 Impairment of oil and natural gas properties — 571,442 — — 571,442 General and administrative expenses 27,218 (12,675 ) 116 — 14,659 Accretion expense — 747 — — 747 29,709 827,600 282 — 857,591 LOSS FROM OPERATIONS (2,351 ) (569,783 ) (282 ) — (572,416 ) OTHER EXPENSE (INCOME): Interest expense 35,105 (1,010 ) — — 34,095 Interest income (187 ) (151 ) — — (338 ) Gain on debt extinguishment (23,600 ) — — — (23,600 ) Loss from equity method investments and investments in subsidiaries 616,348 — 40 (573,306 ) 43,082 Other (income) expense (1,168 ) 3,362 — 1,000 3,194 626,498 2,201 40 (572,306 ) 56,433 LOSS BEFORE INCOME TAXES (628,849 ) (571,984 ) (322 ) 572,306 (628,849 ) INCOME TAX BENEFIT (144,047 ) — — — (144,047 ) NET LOSS $ (484,802 ) $ (571,984 ) $ (322 ) $ 572,306 $ (484,802 ) CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Three months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 235,683 $ 125,279 $ — $ — $ 360,962 Costs and expenses: Lease operating expenses 16,502 5,823 — — 22,325 Production taxes 4,505 4,843 — — 9,348 Midstream gathering and processing expenses 54,397 24,516 — — 78,913 Depreciation, depletion and amortization 119,914 1 — — 119,915 General and administrative expenses 16,314 (467 ) 1 — 15,848 Accretion expense 812 225 — — 1,037 212,444 34,941 1 — 247,386 INCOME (LOSS) FROM OPERATIONS 23,239 90,338 (1 ) — 113,576 OTHER (INCOME) EXPENSE: Interest expense 34,254 (1,001 ) — — 33,253 Interest income (86 ) (6 ) — — (92 ) Gain on sale of equity method investments (2,733 ) — — — (2,733 ) (Income) loss from equity method investments and investments in subsidiaries (104,226 ) (1 ) 275 91,094 (12,858 ) Other expense (income) 880 (24 ) — — 856 (71,911 ) (1,032 ) 275 91,094 18,426 INCOME (LOSS) BEFORE INCOME TAXES 95,150 91,370 (276 ) (91,094 ) 95,150 INCOME TAX BENEFIT — — — — — NET INCOME (LOSS) $ 95,150 $ 91,370 $ (276 ) $ (91,094 ) $ 95,150 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Nine months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Total revenues $ 493,895 $ 570,852 $ — $ — $ 1,064,747 Costs and expenses: Lease operating expenses 26,918 37,750 — — 64,668 Production taxes 6,117 16,467 — — 22,584 Midstream gathering and processing expenses 71,420 149,312 — — 220,732 Depreciation, depletion, and amortization 201,250 205,183 221 — 406,654 Impairment of oil and gas properties — 571,442 — — 571,442 General and administrative expenses 56,195 (16,933 ) 220 — 39,482 Accretion expense 1,389 1,784 — — 3,173 363,289 965,005 441 — 1,328,735 INCOME (LOSS) FROM OPERATIONS 130,606 (394,153 ) (441 ) — (263,988 ) OTHER EXPENSE (INCOME): Interest expense 105,364 (2,269 ) — — 103,095 Interest income (454 ) (195 ) — — (649 ) Gain on debt extinguishment (23,600 ) — — — (23,600 ) Loss from equity method investments and investments in subsidiaries 560,883 — 379 (396,871 ) 164,391 Other (income) expense (605 ) 3,362 — 1,000 3,757 641,588 898 379 (395,871 ) 246,994 LOSS BEFORE INCOME TAXES (510,982 ) (395,051 ) (820 ) 395,871 (510,982 ) INCOME TAX BENEFIT (323,378 ) — — — (323,378 ) NET LOSS $ (187,604 ) $ (395,051 ) $ (820 ) $ 395,871 $ (187,604 ) CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) Nine months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Total revenues $ 596,018 $ 343,076 $ — $ — $ 939,094 Costs and expenses: Lease operating expenses 46,926 17,217 — — 64,143 Production taxes 13,309 10,552 — — 23,861 Midstream gathering and processing expenses 152,605 61,941 — — 214,546 Depreciation, depletion, and amortization 352,846 2 — — 352,848 General and administrative expenses 45,100 (2,148 ) 3 — 42,955 Accretion expense 2,397 659 — — 3,056 613,183 88,223 3 — 701,409 (LOSS) INCOME FROM OPERATIONS (17,165 ) 254,853 (3 ) — 237,685 OTHER (INCOME) EXPENSE: Interest expense 103,310 (2,388 ) — — 100,922 Interest income (144 ) (18 ) — — (162 ) Gain on sale of equity method investments (28,349 ) (96,419 ) — — (124,768 ) (Income) loss from equity method investments and investments in subsidiaries (387,991 ) (694 ) 833 352,570 (35,282 ) Other (income) expense (481 ) (34 ) — 1,000 485 (313,655 ) (99,553 ) 833 353,570 (58,805 ) INCOME (LOSS) BEFORE INCOME TAXES 296,490 354,406 (836 ) (353,570 ) 296,490 INCOME TAX BENEFIT (69 ) — — — (69 ) NET INCOME (LOSS) $ 296,559 $ 354,406 $ (836 ) $ (353,570 ) $ 296,559
CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS)	CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Amounts in thousands) Three months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Net loss $ (484,802 ) $ (571,984 ) $ (322 ) $ 572,306 $ (484,802 ) Foreign currency translation adjustment (2,064 ) (43 ) (2,021 ) 2,064 (2,064 ) Other comprehensive loss (2,064 ) (43 ) (2,021 ) 2,064 (2,064 ) Comprehensive loss $ (486,866 ) $ (572,027 ) $ (2,343 ) $ 574,370 $ (486,866 ) Three months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 95,150 $ 91,370 $ (276 ) $ (91,094 ) $ 95,150 Foreign currency translation adjustment 3,052 103 2,949 (3,052 ) 3,052 Other comprehensive income 3,052 103 2,949 (3,052 ) 3,052 Comprehensive income $ 98,202 $ 91,473 $ 2,673 $ (94,146 ) $ 98,202 Nine months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Net loss $ (187,604 ) $ (395,051 ) $ (820 ) $ 395,871 $ (187,604 ) Foreign currency translation adjustment 5,347 112 5,235 (5,347 ) 5,347 Other comprehensive income 5,347 112 5,235 (5,347 ) 5,347 Comprehensive (loss) income $ (182,257 ) $ (394,939 ) $ 4,415 $ 390,524 $ (182,257 ) Nine months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Net income (loss) $ 296,559 $ 354,406 $ (836 ) $ (353,570 ) $ 296,559 Foreign currency translation adjustment (5,815 ) (70 ) (5,745 ) 5,815 (5,815 ) Other comprehensive loss (5,815 ) (70 ) (5,745 ) 5,815 (5,815 ) Comprehensive income (loss) $ 290,744 $ 354,336 $ (6,581 ) $ (347,755 ) $ 290,744
CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS	CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Amounts in thousands) Nine months ended September 30, 2019 Parent Guarantors Non-Guarantors Eliminations Consolidated As Restated Net cash (used in) provided by operating activities $ (7,604 ) $ 621,511 $ 3,445 $ 3 $ 617,355 Net cash provided by (used in) investing activities 9,178 (644,507 ) (3,751 ) 432 (638,648 ) Net cash (used in) provided by financing activities (20,880 ) — 435 (435 ) (20,880 ) Net (decrease) increase in cash, cash equivalents and restricted cash (19,306 ) (22,996 ) 129 — (42,173 ) Cash, cash equivalents and restricted cash at beginning of period 25,585 26,711 1 — 52,297 Cash, cash equivalents and restricted cash at end of period $ 6,279 $ 3,715 $ 130 $ — $ 10,124 Nine months ended September 30, 2018 Parent Guarantors Non-Guarantor Eliminations Consolidated Net cash provided by (used in) operating activities $ 427,351 $ 203,446 $ (1 ) $ 1 $ 630,797 Net cash (used in) provided by investing activities (354,848 ) (199,738 ) (2,318 ) 2,318 (554,586 ) Net cash (used in) provided by financing activities (51,197 ) — 2,319 (2,319 ) (51,197 ) Net increase in cash, cash equivalents and restricted cash 21,306 3,708 — — 25,014 Cash, cash equivalents and restricted cash at beginning of period 67,908 31,649 — — 99,557 Cash, cash equivalents and restricted cash at end of period $ 89,214 $ 35,357 $ — $ — $ 124,571

BASIS OF PRESENTATION AND SUM_4

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by (used in) operating activities	$ 617,355	$ 630,797
Adjusted to increase net cash flows provided by investing activities	(638,648)	$ (554,586)
Misclassification between Operation and Financing Activities
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by (used in) operating activities	21,800
Adjusted to increase net cash flows provided by investing activities	$ 21,800

BASIS OF PRESENTATION AND SUM_5

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated depletion, depreciation, amortization and impairment	$ (5,616,988)			$ (4,640,098)
Property and equipment, net	5,030,958			5,479,405
Deferred tax asset	323,378			0
Total other assets	501,803			255,268
Total assets	5,837,098			6,051,036
Accumulated deficit	(1,032,972)			(845,368)
Total stockholders’ equity	3,123,104	$ 3,607,408	$ 3,368,266	3,327,768	$ 3,292,015	$ 3,195,199	$ 3,088,889	$ 3,101,614
Total liabilities and stockholders’ equity	5,837,098			6,051,036
Capitalized costs of oil and natural gas properties excluded from amortization	2,260,759			$ 2,873,037
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated depletion, depreciation, amortization and impairment	(5,063,413)
Property and equipment, net	5,584,533
Deferred tax asset	205,853
Total other assets	384,278
Total assets	6,273,148
Accumulated deficit	(596,922)
Total stockholders’ equity	3,559,154
Total liabilities and stockholders’ equity	6,273,148
Capitalized costs of oil and natural gas properties excluded from amortization	2,814,334
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated depletion, depreciation, amortization and impairment	(553,575)
Property and equipment, net	(553,575)
Deferred tax asset	117,525
Total other assets	117,525
Total assets	(436,050)
Accumulated deficit	(436,050)
Total stockholders’ equity	(436,050)
Total liabilities and stockholders’ equity	(436,050)
Capitalized costs of oil and natural gas properties excluded from amortization	$ (553,575)

BASIS OF PRESENTATION AND SUM_6

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Consolidated Statements of Operations (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Depletion, depreciation and amortization	$ 163,270,000			$ 119,915,000			$ 406,654,000	$ 352,848,000
Impairment of oil and natural gas properties	571,442,000			0			571,442,000	0
Total costs and expenses	857,591,000			247,386,000			1,328,735,000	701,409,000
(LOSS) INCOME FROM OPERATIONS	(572,416,000)			113,576,000			(263,988,000)	237,685,000
LOSS BEFORE INCOME TAXES	(628,849,000)			95,150,000			(510,982,000)	296,490,000
INCOME TAX BENEFIT	(144,047,000)			0			(323,378,000)	(69,000)
Net loss	$ (484,802,000)	$ 234,956,000	$ 62,242,000	$ 95,150,000	$ 111,319,000	$ 90,090,000	$ (187,604,000)	$ 296,559,000
Basic (in usd per share)	$ (3.04)			$ 0.55			$ (1.17)	$ 1.69
Diluted (in usd per share)	$ (3.04)			$ 0.55			$ (1.17)	$ 1.68
Weighted average common shares outstanding - Diluted (in shares)	159,548,477			173,304,914			160,553,796	176,440,461
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Depletion, depreciation and amortization	$ 145,490,000						$ 388,874,000
Impairment of oil and natural gas properties	35,647,000						35,647,000
Total costs and expenses	304,016,000						775,160,000
(LOSS) INCOME FROM OPERATIONS	(18,841,000)						289,587,000
LOSS BEFORE INCOME TAXES	(75,274,000)						42,593,000
INCOME TAX BENEFIT	(26,522,000)						(205,853,000)
Net loss	$ (48,752,000)						$ 248,446,000
Basic (in usd per share)	$ (0.31)						$ 1.55
Diluted (in usd per share)	$ (0.31)						$ 1.51
Weighted average common shares outstanding - Diluted (in shares)							164,820,002
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Depletion, depreciation and amortization	$ 17,780,000						$ 17,780,000
Impairment of oil and natural gas properties	535,795,000						535,795,000
Total costs and expenses	553,575,000						553,575,000
(LOSS) INCOME FROM OPERATIONS	(553,575,000)						(553,575,000)
LOSS BEFORE INCOME TAXES	(553,575,000)						(553,575,000)
INCOME TAX BENEFIT	(117,525,000)						(117,525,000)
Net loss	$ (436,050,000)						$ (436,050,000)
Basic (in usd per share)	$ (2.73)						$ (2.72)
Diluted (in usd per share)	$ (2.73)						$ (2.68)
Weighted average common shares outstanding - Diluted (in shares)							(4,266,206)

BASIS OF PRESENTATION AND SUM_7

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Consolidated Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (484,802)	$ 234,956	$ 62,242	$ 95,150	$ 111,319	$ 90,090	$ (187,604)	$ 296,559
Comprehensive (loss) income	(486,866)			98,202			(182,257)	$ 290,744
Accumulated Deficit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(484,802)	$ 234,956	$ 62,242	$ 95,150	$ 111,319	$ 90,090
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(48,752)						248,446
Comprehensive (loss) income	(50,816)						253,793
As Reported | Accumulated Deficit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(48,752)
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(436,050)						(436,050)
Comprehensive (loss) income	(436,050)						$ (436,050)
Adjustments | Accumulated Deficit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (436,050)

BASIS OF PRESENTATION AND SUM_8

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Consolidated Statements of Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (484,802)	$ 234,956	$ 62,242	$ 95,150	$ 111,319	$ 90,090	$ (187,604)	$ 296,559
Total stockholders’ equity	3,123,104	3,607,408	3,368,266	3,292,015	3,195,199	3,088,889	3,123,104	3,292,015	$ 3,327,768	$ 3,101,614
Accumulated Deficit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(484,802)	234,956	62,242	95,150	111,319	90,090
Total stockholders’ equity	(1,032,972)	$ (548,170)	$ (783,126)	$ (979,369)	$ (1,074,519)	$ (1,185,838)	(1,032,972)	$ (979,369)	$ (845,368)	$ (1,275,928)
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(48,752)						248,446
Total stockholders’ equity	3,559,154						3,559,154
As Reported | Accumulated Deficit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(48,752)
Total stockholders’ equity	(596,922)						(596,922)
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(436,050)						(436,050)
Total stockholders’ equity	(436,050)						(436,050)
Adjustments | Accumulated Deficit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(436,050)
Total stockholders’ equity	$ (436,050)						$ (436,050)

BASIS OF PRESENTATION AND SUM_9

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Consolidated Statements of Cash Flows (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (484,802,000)	$ 234,956,000	$ 62,242,000	$ 95,150,000	$ 111,319,000	$ 90,090,000	$ (187,604,000)	$ 296,559,000
Depletion, depreciation and amortization	163,270,000			119,915,000			406,654,000	352,848,000
Impairment of oil and natural gas properties	571,442,000			$ 0			571,442,000	0
Deferred income tax benefit							(323,378,000)	$ (69,000)
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(48,752,000)						248,446,000
Depletion, depreciation and amortization	145,490,000						388,874,000
Impairment of oil and natural gas properties	35,647,000						35,647,000
Deferred income tax benefit							(205,853,000)
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(436,050,000)						(436,050,000)
Depletion, depreciation and amortization	17,780,000						17,780,000
Impairment of oil and natural gas properties	$ 535,795,000						535,795,000
Deferred income tax benefit							$ (117,525,000)

PROPERTY AND EQUIPMENT (Schedul

PROPERTY AND EQUIPMENT (Schedule of Property and Equipment) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Oil and natural gas properties	$ 10,551,713	$ 10,026,836
Other depreciable property and equipment	90,712	87,146
Land	5,521	5,521
Total property and equipment	10,647,946	10,119,503
Accumulated depletion, depreciation, amortization and impairment	(5,616,988)	(4,640,098)
Property and equipment, net	$ 5,030,958	$ 5,479,405

PROPERTY AND EQUIPMENT (Narrati

PROPERTY AND EQUIPMENT (Narrative) (Details)	Jul. 03, 2019USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)usd_per_mcf	Sep. 30, 2018USD ($)usd_per_mcf	Dec. 31, 2018USD ($)
Property, Plant and Equipment [Line Items]
Impairment of oil and natural gas properties		$ 571,442,000	$ 0	$ 571,442,000	$ 0
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool		229,600,000		229,600,000
Capitalized general and administrative costs		9,800,000	$ 10,600,000	$ 26,300,000	$ 28,800,000
Depletion per Mcfe of gas equivalent (usd per Mcfe) | usd_per_mcf				1.05	0.94
Non-producing leasehold costs		$ 2,260,759,000		$ 2,260,759,000		$ 2,873,037,000
Non-producing leases, extension term		5 years		5 years
Payments to acquire businesses	$ 9,200,000
Disposal group, including discontinued operation, contingent payment period	2 years
Asset retirement obligation, liabilities removed due to divestitures				$ 30,000,000
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
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Property, Plant and Equipment [Line Items]
Total consideration	$ 19,700,000

PROPERTY AND EQUIPMENT (Summary

PROPERTY AND EQUIPMENT (Summary of Non-producing Properties Excluded from Amortization by Area) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total non-producing properties not subject to amortization	$ 2,260,759	$ 2,873,037
Utica
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total non-producing properties not subject to amortization	1,112,148
MidContinent
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total non-producing properties not subject to amortization	1,148,271
Other
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Total non-producing properties not subject to amortization	$ 340

PROPERTY AND EQUIPMENT (Sched_2

PROPERTY AND EQUIPMENT (Schedule of Asset Retirement Obligation) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation, beginning of period			$ 79,952	$ 75,100
Liabilities incurred			5,769	1,468
Liabilities settled			(117)	(719)
Liabilities removed due to divestitures			(30,035)	0
Accretion expense	$ 747	$ 1,037	3,173	3,056
Revisions in estimated cash flows			1,077	(374)
Asset retirement obligation as of end of period	59,819	78,531	59,819	78,531
Less current portion	0	120	0	120
Asset retirement obligation, long-term	$ 59,819	$ 78,411	$ 59,819	$ 78,411	$ 79,952

EQUITY INVESMENTS (Investments

EQUITY INVESMENTS (Investments Accounted for by the Equity Method) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	May 01, 2018
Schedule of Equity Method Investments [Line Items]
Equity investments and investments in subsidiaries	$ 73,962		$ 73,962		$ 236,121
Loss (income) from equity method investments, net	$ 43,082	$ (12,858)	$ 164,391	$ (35,282)
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
Loss (income) from equity method investments, net	$ 0	(137)	$ (2,085)	(241)
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	$ 49,546		$ 49,546		44,259
Loss (income) from equity method investments, net	$ 41	275	$ 380	833
Investment in Timber Wolf Terminals LLC(1)
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	0.00%		0.00%
Equity investments and investments in subsidiaries	$ 0		$ 0		0
Loss (income) from equity method investments, net	$ 0	0	$ 0	536
Investment in Windsor Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	22.50%		22.50%
Equity investments and investments in subsidiaries	$ 39		$ 39		39
Loss (income) from equity method investments, net	0	0	0	(9)
Investment in Mammoth Energy Services, Inc.
Schedule of Equity Method Investments [Line Items]
Equity investments and investments in subsidiaries	24,377		24,377		191,823
Loss (income) from equity method investments, net	$ 43,041	(12,996)	$ 166,096	(35,708)
Investment in Strike Force Midstream LLC
Schedule of Equity Method Investments [Line Items]
Approximate ownership %	0.00%		0.00%			25.00%
Equity investments and investments in subsidiaries	$ 0		$ 0		$ 0
Loss (income) from equity method investments, net	$ 0	$ 0	$ 0	$ (693)

EQUITY INVESMENTS (Equity Inves

EQUITY INVESMENTS (Equity Investments Balance Sheet Disclosure) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Current assets	$ 427,643	$ 471,733
Noncurrent assets	1,309,729	1,302,488
Current liabilities	130,465	239,975
Noncurrent liabilities	$ 176,145	$ 94,575

EQUITY INVESMENTS (Equity Inv_2

EQUITY INVESMENTS (Equity Investment Income Statement Disclosure) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Gross revenue	$ 113,417	$ 384,043	$ 557,375	$ 1,451,580
Net (loss) income	$ (35,730)	$ 68,414	$ (15,046)	$ 181,884

EQUITY INVESMENTS (Narrative) (

EQUITY INVESMENTS (Narrative) (Details) $ / shares in Units, a in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)shares	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)a$ / sharesshares	Sep. 30, 2018USD ($)	May 31, 2018	May 01, 2018
Schedule of Equity Method Investments [Line Items]
Loss (income) from equity method investments, net	$ 43,082,000	$ (12,858,000)	$ 164,391,000	$ (35,282,000)
Distributions from equity method investments			1,945,000	446,000
Mammoth Energy Services LP
Schedule of Equity Method Investments [Line Items]
Equity method investment, impairment	$ 35,500,000		160,800,000
Distributions from equity method investments			$ 2,500,000
Equity method investment, ownership interest (in shares) | shares	9,829,548		9,829,548
Share dividend (in usd per share) | $ / shares			$ 0.125
Approximate fair value, quoted market price	$ 24,400,000		$ 24,400,000
Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Loss (income) from equity method investments, net	$ 0	(137,000)	$ (2,085,000)	(241,000)
Equity method investment, ownership interest, percent	23.50%		23.50%
Grizzly Oil Sands ULC
Schedule of Equity Method Investments [Line Items]
Gas and oil area, reserve (in acres) | a			830
Loss (income) from equity method investments, net	$ 41,000	275,000	$ 380,000	833,000
Equity method investment, ownership interest, percent	24.9999%		24.9999%
Equity method investment, impairment			$ 0	0
Equity method investment, amount of cash calls, based on proportionate ownership interest			400,000
Equity method investments, increase (decrease) due to foreign currency translation adjustment	$ (2,000,000)	2,900,000	5,200,000	(5,700,000)
Windsor Midstream LLC
Schedule of Equity Method Investments [Line Items]
Loss (income) from equity method investments, net	$ 0	0	$ 0	(9,000)
Equity method investment, ownership interest, percent	22.50%		22.50%
Distributions from equity method investments			$ 0
Mammoth Energy Services LP
Schedule of Equity Method Investments [Line Items]
Equity method investments, increase (decrease) due to foreign currency translation adjustment	$ (100,000)	100,000	100,000	(200,000)
Strike Force Midstream LLC
Schedule of Equity Method Investments [Line Items]
Loss (income) from equity method investments, net	$ 0	$ 0	$ 0	$ (693,000)
Equity method investment, ownership interest, percent	0.00%		0.00%			25.00%
Phu Horm Field | Apico Llc
Schedule of Equity Method Investments [Line Items]
Gas and oil area, reserve (in acres) | a			108
Apico Llc | Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	8.50%		8.50%
Apico Llc | Tatex Thailand II, LLC
Schedule of Equity Method Investments [Line Items]
Loss (income) from equity method investments, net			$ 1,900,000
Investee | Mammoth Energy Services LP
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent	21.80%		21.80%
Investee | Strike Force Midstream LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership interest, percent					25.00%

LONG-TERM DEBT (Break-Down of L

LONG-TERM DEBT (Break-Down of Long-Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Net unamortized debt issuance costs	$ (26,052)	$ (30,733)
Less: current maturities of long term debt	(622)	(651)
Long-term debt, net of current maturities	2,076,569	2,086,765
Construction loan
Debt Instrument [Line Items]
Net unamortized debt issuance costs	(100)
6.625% senior unsecured notes due 2023 | Senior notes
Debt Instrument [Line Items]
Long-term debt	340,000	350,000
Net unamortized debt issuance costs	$ (3,600)
Stated interest rate, percent	6.625%
6.000% senior unsecured notes due 2024 | Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 630,796	650,000
Net unamortized debt issuance costs	$ (7,500)
Stated interest rate, percent	6.00%
6.375% senior unsecured notes due 2025 | Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 577,268	600,000
Net unamortized debt issuance costs	$ (10,800)
Stated interest rate, percent	6.375%
6.375% senior unsecured notes due 2026 | Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 397,529	450,000
Net unamortized debt issuance costs	$ (4,000)
Stated interest rate, percent	6.375%
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Revolving credit agreement
Debt Instrument [Line Items]
Long-term debt	$ 135,000	45,000
InterBank | Letter of credit | Construction loan
Debt Instrument [Line Items]
Long-term debt	$ 22,650	$ 23,149

LONG-TERM DEBT (Narrative) (Det

LONG-TERM DEBT (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 03, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt issuance costs, net	$ 26,052,000		$ 26,052,000			$ 30,733,000
Capitalized interest expense, undeveloped properties	1,000,000	$ 1,600,000	2,800,000	$ 4,000,000
Gain on debt extinguishment	(23,600,000)	$ 0	(23,600,000)	$ 0
Revolving Credit Facility
Debt Instrument [Line Items]
Aggregate principal amount	104,400,000		104,400,000
Repurchase amount	80,300,000		80,300,000
Gain on debt extinguishment			(23,600,000)
Construction loan
Debt Instrument [Line Items]
Debt issuance costs, net	100,000		100,000
6.000% senior unsecured notes due 2024 | Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 630,796,000		$ 630,796,000			650,000,000
Stated interest rate, percent	6.00%		6.00%
Debt issuance costs, net	$ 7,500,000		$ 7,500,000
Aggregate principal amount	19,200,000		19,200,000
6.625% senior unsecured notes due 2023 | Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 340,000,000		$ 340,000,000			350,000,000
Stated interest rate, percent	6.625%		6.625%
Debt issuance costs, net	$ 3,600,000		$ 3,600,000
Aggregate principal amount	10,000,000		10,000,000
6.375% senior unsecured notes due 2025 | Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 577,268,000		$ 577,268,000			600,000,000
Stated interest rate, percent	6.375%		6.375%
Debt issuance costs, net	$ 10,800,000		$ 10,800,000
Aggregate principal amount	22,700,000		22,700,000
6.375% senior unsecured notes due 2026 | Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 397,529,000		$ 397,529,000			450,000,000
Stated interest rate, percent	6.375%		6.375%
Debt issuance costs, net	$ 4,000,000		$ 4,000,000
Aggregate principal amount	52,500,000		$ 52,500,000
Nova Scotia, Amegy, KeyBank | Revolving credit agreement
Debt Instrument [Line Items]
Credit facility interest rate at the eurodollar rate			3.52%
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Revolving credit agreement
Debt Instrument [Line Items]
Borrowing base					$ 1,400,000,000
Elected commitment amount					$ 1,000,000,000
Long-term debt	135,000,000		$ 135,000,000			$ 45,000,000
Remaining borrowing capacity	616,400,000		616,400,000
Nova Scotia, Amegy, KeyBank | Letter of credit | Revolving credit agreement
Debt Instrument [Line Items]
Credit facility outstanding	$ 248,600,000		$ 248,600,000

COMMON STOCK AND CHANGES IN C_2

COMMON STOCK AND CHANGES IN CAPITALIZATION (Details) - USD ($)	1 Months Ended	3 Months Ended						9 Months Ended	12 Months Ended
	Jan. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Dec. 31, 2018	May 31, 2018	Jan. 31, 2018
Class of Stock [Line Items]
Stock repurchase program, amount authorized to acquire											$ 100,000,000
Value of shares repurchased during the period									$ 200,000,000
Stock repurchase program, period in force	24 months
Value of shares repurchased		$ 89,000	$ 2,270,000	$ 28,330,000	$ 5,000,000	$ 5,000,000	$ 99,997,000
Share purchased to satisfy tax withholding requirements (in shares)		100,000						100,000
Shares repurchased to satisfy tax withholding requirements		$ 100,000						$ 700,000
Common Stock
Class of Stock [Line Items]
Shares repurchased (in shares)		35,977	296,587	3,618,634	400,597	412,516	9,692,356
Value of shares repurchased		$ 0	$ 3,000	$ 37,000	$ 4,000	$ 4,000	$ 97,000
Minimum
Class of Stock [Line Items]
Stock repurchase program, amount authorized to acquire										$ 100,000,000
Maximum
Class of Stock [Line Items]
Stock repurchase program, amount authorized to acquire										$ 200,000,000
Share Repurchase Program
Class of Stock [Line Items]
Shares repurchased (in shares)									20,700,000
Share Repurchase Program | Common Stock
Class of Stock [Line Items]
Shares repurchased (in shares)								3,800,000
Value of shares repurchased								$ 30,000,000

STOCK-BASED COMPENSATION (Narra

STOCK-BASED COMPENSATION (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation cost	$ 2.7	$ 3.6	$ 8.3	$ 9.7
Capitalized stock-based compensation cost	1.1	$ 1.4	$ 3.3	$ 3.9
Percent of target based award, minimum			0.00%
Percent of target based award, maximum			200.00%
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	19		$ 19
Weighted average period of expense recognition period			2 years 3 months 10 days
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 4.9		$ 4.9
Weighted average period of expense recognition period			2 years 7 months 20 days
Expected performance period			2 years
Risk free interest rate, minimum			1.56%
Risk free interest rate, maximum			2.42%
Range of expected volatility, minimum			29.10%
Range of expected volatility, maximum			85.10%
Minimum | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			1 year
Maximum | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years

STOCK-BASED COMPENSATION (Restr

STOCK-BASED COMPENSATION (Restricted Stock Award and Unit Activity) (Details)	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Restricted Stock
Number of Unvested Restricted Shares
Unvested shares, beginning balance (in shares) | shares	1,535,811
Granted (in shares) | shares	4,011,073
Vested (in shares) | shares	(674,374)
Forfeited (in shares) | shares	(289,610)
Unvested shares, ending balance (in shares) | shares	4,582,900
Weighted Average Grant Date Fair Value
Unvested shares, beginning balance (in dollars per share) | $ / shares	$ 11.57
Granted (in dollars per share) | $ / shares	3.74
Vested (in dollars per share) | $ / shares	12.86
Forfeited (in dollars per share) | $ / shares	7.83
Unvested shares, ending balance (in dollars per share) | $ / shares	$ 4.76
Performance Shares
Number of Unvested Restricted Shares
Unvested shares, beginning balance (in shares) | shares	0
Granted (in shares) | shares	2,009,144
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(112,742)
Unvested shares, ending balance (in shares) | shares	1,896,402
Weighted Average Grant Date Fair Value
Unvested shares, beginning balance (in dollars per share) | $ / shares	$ 0
Granted (in dollars per share) | $ / shares	2.85
Vested (in dollars per share) | $ / shares	0
Forfeited (in dollars per share) | $ / shares	1.98
Unvested shares, ending balance (in dollars per share) | $ / shares	$ 2.91

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Basic:
Net (loss) income (as restated) - basic	$ (484,802)	$ 95,150	$ (187,604)	$ 296,559
Net (loss) income (as restated) - basic (in shares)	159,548,477	173,057,538	160,553,796	175,776,312
Net (loss) income (as restated) - basic (in usd per share)	$ (3.04)	$ 0.55	$ (1.17)	$ 1.69
Effect of dilutive securities:
Stock options and awards	$ 0	$ 0	$ 0	$ 0
Stock options and awards (in shares)	0	247,376	0	664,149
Diluted:
Net (loss) income (as restated) - diluted	$ (484,802)	$ 95,150	$ (187,604)	$ 296,559
Net (loss) income (as restated) - diluted (in shares)	159,548,477	173,304,914	160,553,796	176,440,461
Net (loss) income (as restated) - diluted (in usd per share)	$ (3.04)	$ 0.55	$ (1.17)	$ 1.68
Anti-dilutive shares	2,073,638	0	4,266,206	0

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Narrative) (Details) $ in Thousands	Apr. 15, 2019violation	Jan. 04, 2017violation	Jul. 29, 2016complaint	Feb. 09, 2016complaint	Dec. 11, 2013site	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)site	Sep. 30, 2018USD ($)
Commitments [Line Items]
FOVs (in sites)	1	1			1			12
Loss contingency accrual | $						$ 100		$ 100
Judicial District Court for the Parish of Cameron
Commitments [Line Items]
Number of claims filed (in claims) | complaint				1
Judicial District Court for the Parish of Vermillion
Commitments [Line Items]
Number of claims filed (in claims) | complaint			1
Loss on long-term purchase commitment | Muskie Proppant LLC
Commitments [Line Items]
Non-utilization fees, accrued damages year to date | $						$ 20	$ 1,300	$ 400	$ 1,500

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES (Future Commitments) (Details) MMBTU in Thousands, $ in Thousands	Sep. 30, 2019USD ($)MMBTU
Commitments [Line Items]
Remaining 2019 (in mmbtu) | MMBTU	424
2020 (in mmbtu) | MMBTU	314
2021 (in mmbtu) | MMBTU	192
2022 (in mmbtu) | MMBTU	70
2023 (in mmbtu) | MMBTU	17
Thereafter (in mmbtu) | MMBTU	0
Total (in mmbtu) | MMBTU	1,017
2020	$ 24,000
2021	24,000
Total	54,000
Transportation commitment
Commitments [Line Items]
Remaining 2019	65,763
2020	287,627
2021	286,665
2022	286,665
2023	282,981
Thereafter	2,410,866
Total	$ 3,620,567

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES (Future Minimum Commitments) (Details) $ in Thousands	Sep. 30, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining 2019	$ 6,000
2020	24,000
2021	24,000
Total	$ 54,000

DERIVATIVE INSTRUMENTS (Narrati

DERIVATIVE INSTRUMENTS (Narrative) (Details) $ in Millions	1 Months Ended	9 Months Ended
	Dec. 31, 2018MMBTU$ / MMBTU	Sep. 30, 2019USD ($)
Derivative [Line Items]
Fair value of contingent consideration asset on date of divestiture | $		$ 1.1
2019
Derivative [Line Items]
Counterparty option to extend the original terms, number of months		12 months
Daily volume (in MMBtu) | MMBTU	100,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU	3.05

DERIVATIVE INSTRUMENTS (Schedul

DERIVATIVE INSTRUMENTS (Schedule of Derivative Instruments) (Details)	Sep. 30, 2017MMBTU	Sep. 30, 2019MMBTU$ / bbl$ / MMBTUbbl
NYMEX Henry Hub Swap - 2019
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU		1,380,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		2.81
NYMEX Henry Hub Swap - 2019 | Short | Call Option
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU		30,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		3.10
NYMEX Henry Hub Swap - 2020
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU		519,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		2.88
NYMEX Henry Hub Swap - 2022 | Short | Call Option
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU		628,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		2.90
NYMEX Henry Hub Swap - 2023 | Short | Call Option
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU	628,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		2.90
NYMEX WTI Swap - 2019
Derivative [Line Items]
Daily Volume (Bbls/day) | bbl		6,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl		60.81
NYMEX WTI Swap - 2020
Derivative [Line Items]
Daily Volume (Bbls/day) | bbl		6,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl		59.82
Mont Belvieu C2 - 2019
Derivative [Line Items]
Daily Volume (Bbls/day) | bbl		1,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl		18.48
Mont Belvieu C3 Swap - 2019
Derivative [Line Items]
Daily Volume (Bbls/day) | bbl		4,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl		29.02
Mont Belvieu C5 Swap - 2019
Derivative [Line Items]
Daily Volume (Bbls/day) | bbl		1,000
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl		53.71
Transco Zone 4 - 2019 | Long
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU		60,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		0.05
Transco Zone 4 - 2020 | Long
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU		60,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		0.05
Fixed Spread - 2020 | Long
Derivative [Line Items]
Daily Volume (MMBtu/day) | MMBTU		10,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		0.54

DERIVATIVE INSTRUMENTS (Conting

DERIVATIVE INSTRUMENTS (Contingent Consideration Arrangement) (Details)	9 Months Ended
	Sep. 30, 2019USD ($)$ / shares
Derivative [Line Items]
Derivative, credit risk related contingent features, payment to be received, denominator (in usd per share)	$ 8.03
Derivative Threshold, Greater Than or Equal to $60.65
Derivative [Line Items]
Payment to be received | $	$ 150,000
Derivative, credit risk related contingent features, commodity price threshold (in usd per share)	$ 60.65
Derivative Threshold, Between $52.62 and $60.65
Derivative [Line Items]
Derivative, credit risk related contingent features, commodity price threshold (in usd per share)	52.62
Derivative Threshold, Between $52.62 and $60.65 | Minimum
Derivative [Line Items]
Derivative, credit risk related contingent features, commodity price threshold (in usd per share)	52.62
Derivative Threshold, Between $52.62 and $60.65 | Maximum
Derivative [Line Items]
Derivative, credit risk related contingent features, commodity price threshold (in usd per share)	$ 60.65
Derivative Threshold, Less Than or Equal to $52.62
Derivative [Line Items]
Payment to be received | $	$ 0

DERIVATIVE INSTRUMENTS (Derivat

DERIVATIVE INSTRUMENTS (Derivative Instruments in Financial Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Total short-term derivative instruments - asset	$ 134,571	$ 21,352
Total long-term derivative instruments - asset	23,419	0
Total short-term derivative instruments - liability	429	20,401
Total long-term derivative instruments - liability	72,040	13,992
Commodity derivative instruments
Derivatives, Fair Value [Line Items]
Total short-term derivative instruments - asset	134,511	21,352
Total long-term derivative instruments - asset	23,375	0
Contingent consideration arrangement
Derivatives, Fair Value [Line Items]
Total short-term derivative instruments - asset	60
Total long-term derivative instruments - asset	$ 44	$ 0

DERIVATIVE INSTRUMENTS (Net (Lo

DERIVATIVE INSTRUMENTS (Net (Loss) Gain on Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative [Line Items]
Net gain (loss) on natural gas, oil and NGLs derivatives	$ 27,074	$ (9,663)	$ 178,169	$ (96,737)
Natural gas derivatives
Derivative [Line Items]
Net gain (loss) on natural gas, oil and NGLs derivatives	11,731	14,101	147,774	(26,789)
Oil derivatives
Derivative [Line Items]
Net gain (loss) on natural gas, oil and NGLs derivatives	12,736	(11,610)	24,153	(45,176)
NGLs derivatives
Derivative [Line Items]
Net gain (loss) on natural gas, oil and NGLs derivatives	3,641	(12,154)	7,276	(24,772)
Contingent consideration arrangement
Derivative [Line Items]
Net gain (loss) on natural gas, oil and NGLs derivatives	$ (1,034)	$ 0	$ (1,034)	$ 0

DERIVATIVE INSTRUMENTS (Sched_2

DERIVATIVE INSTRUMENTS (Schedule of Offsetting) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross assets presented in the consolidated balance sheet	$ 157,990	$ 21,352
Gross assets subject to mater netting agreement - assets	(72,469)	(19,289)
Net amount - assets	85,521	2,063
Gross liabilities presented in the consolidated balance sheet	(72,469)	(34,393)
Gross amounts subject to master netting agreement - liabilities	72,469	19,289
Net amount - liabilities	$ 0	$ (15,104)

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Liabilities:
Asset retirement obligation capitalized	$ 5,769	$ 1,468
Level 1
Assets:
Derivative Instruments	0		$ 0
Liabilities:
Derivative Instruments	0		0
Level 2
Assets:
Derivative Instruments	157,990		21,352
Liabilities:
Derivative Instruments	72,469		34,393
Level 3
Assets:
Derivative Instruments	0		0
Liabilities:
Derivative Instruments	$ 0		$ 0

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ 26,052	$ 30,733
Senior notes | 6.625% senior unsecured notes due 2023
Debt Instrument [Line Items]
Unamortized debt issuance costs	3,600
Senior notes | 6.000% senior unsecured notes due 2024
Debt Instrument [Line Items]
Unamortized debt issuance costs	7,500
Senior notes | 6.375% senior unsecured notes due 2025
Debt Instrument [Line Items]
Unamortized debt issuance costs	10,800
Senior notes | 6.375% senior unsecured notes due 2026
Debt Instrument [Line Items]
Unamortized debt issuance costs	4,000
Carry value | Senior notes
Debt Instrument [Line Items]
Carrying value of notes	1,900,000
Fair value | Senior notes
Debt Instrument [Line Items]
Carrying value of notes	$ 1,400,000

REVENUE FROM CONTRACTS WITH C_2

REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Receivables from contracts with customers	$ 112.7	$ 210.2
Performance obligation period	However, settlement statements for certain sales may be received for 30 to 90 days after the date production is delivered, and as a result, the Company is required to estimate the amount of production that was delivered to the purchaser and the price that will be received for the sale of the product.
Maximum
Disaggregation of Revenue [Line Items]
Performance obligation period	P30D

LEASES (Narrative) (Details)

LEASES (Narrative) (Details) - USD ($)	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease assets	$ 13,920,000
Lease liability	62,369,000
Accumulated deficit	$ (1,032,972,000)		$ (845,368,000)
Weighted average remaining lease term	1 year 9 months 25 days
Weighted-average discount rate - operating leases	3.66%
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease assets		$ 110,000,000
Lease liability		110,000,000
Accumulated deficit		$ 0
Minimum
Lessee, Lease, Description [Line Items]
Lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease term	5 years
Drilling Rig | Minimum
Lessee, Lease, Description [Line Items]
Lease term	1 year
Drilling Rig | Maximum
Lessee, Lease, Description [Line Items]
Lease term	2 years

LEASES (Maturities of Lease Lia

LEASES (Maturities of Lease Liabilities) (Details) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
Remaining 2019	$ 10,190
2020	31,460
2021	22,731
2022	115
2023	90
Thereafter	30
Total lease payments	64,616
Less: Imputed interest	(2,247)
Lease liability	$ 62,369

LEASES (Lease Cost) (Details)

LEASES (Lease Cost) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 4,551	$ 20,835
Operating lease cost - related party	5,610	16,830
Variable lease cost	105	1,065
Variable lease cost - related party	5,357	64,968
Short-term lease cost	224	407
Total lease cost	$ 15,847	$ 104,105

LEASES (Other Information) (Det

LEASES (Other Information) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating cash flows from operating leases	$ 146
Investing cash flow from operating leases	18,998
Investing cash flow from operating leases - related party	$ 78,518

INCOME TAXES (Details)

INCOME TAXES (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Income Tax Disclosure [Abstract]
Effective tax rate	50.40%	28.20%
Adjustment of deferred tax asset	$ 27.7	$ 207
Deferred tax realizable	207	207
Deferred taxes	207	207
Foreign tax credits	5	$ 5
Testing period		3 years
Tax expense	$ 1.6	$ 1.7

CONDENSED CONSOLIDATING FINAN_3

CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Balance Sheets) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 10,124			$ 52,297
Accounts receivable - oil and natural gas sales	112,657			210,200
Accounts receivable - joint interest and other	41,327			22,497
Accounts receivable - intercompany	0			0
Prepaid expenses and other current assets	5,658			10,017
Short-term derivative instruments	134,571			21,352
Total current assets	304,337			316,363
Property and equipment:
Oil and natural gas properties	10,551,713			10,026,836
Other property and equipment	96,233			92,667
Accumulated depletion, depreciation, amortization and impairment	(5,616,988)			(4,640,098)
Property and equipment, net	5,030,958			5,479,405
Other assets:
Equity investments and investments in subsidiaries	73,962			236,121
Long-term derivative instruments	23,419			0
Deferred tax asset	323,378			0
Inventories	7,022			5,344
Operating lease assets	13,920
Operating lease assets - related parties	48,449
Other assets	11,653			13,803
Total other assets	501,803			255,268
Total assets	5,837,098			6,051,036
Current liabilities:
Accounts payable and accrued liabilities	439,019			518,380
Accounts payable - intercompany	0			0
Short-term derivative instruments	429			20,401
Current portion of operating lease liabilities	12,848
Current portion of operating lease liabilities - related parties	21,017
Current maturities of long-term debt	622			651
Total current liabilities	473,935			539,432
Long-term derivative instruments	72,040			13,992
Asset retirement obligation—long-term	59,819			79,952	$ 78,411
Uncertain tax position liability	3,127			3,127
Non-current operating lease liabilities	1,072
Non-current operating lease liabilities - related parties	27,432
Long-term debt, net of current maturities	2,076,569			2,086,765
Total liabilities	2,713,994			2,723,268
Stockholders’ equity:
Common stock	1,597			1,630
Paid-in capital	4,205,158			4,227,532
Accumulated other comprehensive loss	(50,679)			(56,026)
(Accumulated deficit) retained earnings	(1,032,972)			(845,368)
Total stockholders’ equity	3,123,104	$ 3,607,408	$ 3,368,266	3,327,768	$ 3,292,015	$ 3,195,199	$ 3,088,889	$ 3,101,614
Total liabilities and stockholders’ equity	5,837,098			6,051,036
Reportable legal entities | Parent
Current assets:
Cash and cash equivalents	6,279			25,585
Accounts receivable - oil and natural gas sales	857			146,075
Accounts receivable - joint interest and other	6,909			16,212
Accounts receivable - intercompany	953,446			671,633
Prepaid expenses and other current assets	3,886			7,843
Short-term derivative instruments	134,571			21,352
Total current assets	1,105,948			888,700
Property and equipment:
Oil and natural gas properties	1,312,715			7,044,550
Other property and equipment	92,163			91,916
Accumulated depletion, depreciation, amortization and impairment	(1,416,248)			(4,640,059)
Property and equipment, net	(11,370)			2,496,407
Other assets:
Equity investments and investments in subsidiaries	4,553,316			2,856,988
Long-term derivative instruments	23,419
Deferred tax asset	323,378
Inventories	94			4,210
Operating lease assets	13,920
Operating lease assets - related parties	48,449
Other assets	11,333			12,624
Total other assets	4,973,909			2,873,822
Total assets	6,068,487			6,258,929
Current liabilities:
Accounts payable and accrued liabilities	69,863			419,107
Accounts payable - intercompany	660,364			320,259
Short-term derivative instruments	429			20,401
Current portion of operating lease liabilities	12,848
Current portion of operating lease liabilities - related parties	21,017
Current maturities of long-term debt	622			651
Total current liabilities	765,143			760,418
Long-term derivative instruments	72,040			13,992
Asset retirement obligation—long-term	0			66,859
Uncertain tax position liability	3,127			3,127
Non-current operating lease liabilities	1,072
Non-current operating lease liabilities - related parties	27,432
Long-term debt, net of current maturities	2,076,569			2,086,765
Total liabilities	2,945,383			2,931,161
Stockholders’ equity:
Common stock	1,597			1,630
Paid-in capital	4,205,158			4,227,532
Accumulated other comprehensive loss	(50,679)			(56,026)
(Accumulated deficit) retained earnings	(1,032,972)			(845,368)
Total stockholders’ equity	3,123,104			3,327,768
Total liabilities and stockholders’ equity	6,068,487			6,258,929
Reportable legal entities | Guarantors
Current assets:
Cash and cash equivalents	3,715			26,711
Accounts receivable - oil and natural gas sales	111,800			64,125
Accounts receivable - joint interest and other	34,418			6,285
Accounts receivable - intercompany	625,306			319,464
Prepaid expenses and other current assets	1,697			2,174
Short-term derivative instruments	0			0
Total current assets	776,936			418,759
Property and equipment:
Oil and natural gas properties	9,239,581			2,983,015
Other property and equipment	751			751
Accumulated depletion, depreciation, amortization and impairment	(4,200,519)			(39)
Property and equipment, net	5,039,813			2,983,727
Other assets:
Equity investments and investments in subsidiaries				0
Long-term derivative instruments	0
Deferred tax asset	0
Inventories	6,928			1,134
Operating lease assets	0
Operating lease assets - related parties	0
Other assets	320			1,178
Total other assets	7,248			2,312
Total assets	5,823,997			3,404,798
Current liabilities:
Accounts payable and accrued liabilities	369,129			99,273
Accounts payable - intercompany	914,401			670,708
Short-term derivative instruments	0			0
Current portion of operating lease liabilities	0
Current portion of operating lease liabilities - related parties	0
Current maturities of long-term debt	0			0
Total current liabilities	1,283,530			769,981
Long-term derivative instruments	0			0
Asset retirement obligation—long-term	59,819			13,093
Uncertain tax position liability	0			0
Non-current operating lease liabilities	0
Non-current operating lease liabilities - related parties	0
Long-term debt, net of current maturities	0			0
Total liabilities	1,343,349			783,074
Stockholders’ equity:
Common stock	0			0
Paid-in capital	4,170,573			1,915,598
Accumulated other comprehensive loss	0			0
(Accumulated deficit) retained earnings	310,075			706,126
Total stockholders’ equity	4,480,648			2,621,724
Total liabilities and stockholders’ equity	5,823,997			3,404,798
Reportable legal entities | Non-Guarantors
Current assets:
Cash and cash equivalents	130			1
Accounts receivable - oil and natural gas sales	0			0
Accounts receivable - joint interest and other	0			0
Accounts receivable - intercompany	0			0
Prepaid expenses and other current assets	75			0
Short-term derivative instruments	0			0
Total current assets	205			1
Property and equipment:
Oil and natural gas properties	146			0
Other property and equipment	3,319			0
Accumulated depletion, depreciation, amortization and impairment	(221)			0
Property and equipment, net	3,244			0
Other assets:
Equity investments and investments in subsidiaries	49,545			44,259
Long-term derivative instruments	0
Deferred tax asset	0
Inventories	0			0
Operating lease assets	0
Operating lease assets - related parties	0
Other assets	0			0
Total other assets	49,545			44,259
Total assets	52,994			44,260
Current liabilities:
Accounts payable and accrued liabilities	27			0
Accounts payable - intercompany	3,987			130
Short-term derivative instruments	0			0
Current portion of operating lease liabilities	0
Current portion of operating lease liabilities - related parties	0
Current maturities of long-term debt	0			0
Total current liabilities	4,014			130
Long-term derivative instruments	0			0
Asset retirement obligation—long-term	0			0
Uncertain tax position liability	0			0
Non-current operating lease liabilities	0
Non-current operating lease liabilities - related parties	0
Long-term debt, net of current maturities	0			0
Total liabilities	4,014			130
Stockholders’ equity:
Common stock	0			0
Paid-in capital	262,061			261,626
Accumulated other comprehensive loss	(48,548)			(53,783)
(Accumulated deficit) retained earnings	(164,533)			(163,713)
Total stockholders’ equity	48,980			44,130
Total liabilities and stockholders’ equity	52,994			44,260
Eliminations
Current assets:
Cash and cash equivalents	0			0
Accounts receivable - oil and natural gas sales	0			0
Accounts receivable - joint interest and other	0			0
Accounts receivable - intercompany	(1,578,752)			(991,097)
Prepaid expenses and other current assets	0			0
Short-term derivative instruments	0			0
Total current assets	(1,578,752)			(991,097)
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	(4,528,899)			(2,665,126)
Long-term derivative instruments	0
Deferred tax asset	0
Inventories	0			0
Operating lease assets	0
Operating lease assets - related parties	0
Other assets	0			1
Total other assets	(4,528,899)			(2,665,125)
Total assets	(6,108,380)			(3,656,951)
Current liabilities:
Accounts payable and accrued liabilities	0			0
Accounts payable - intercompany	(1,578,752)			(991,097)
Short-term derivative instruments	0			0
Current portion of operating lease liabilities	0
Current portion of operating lease liabilities - related parties	0
Current maturities of long-term debt	0			0
Total current liabilities	(1,578,752)			(991,097)
Long-term derivative instruments	0			0
Asset retirement obligation—long-term	0			0
Uncertain tax position liability	0			0
Non-current operating lease liabilities	0
Non-current operating lease liabilities - related parties	0
Long-term debt, net of current maturities	0			0
Total liabilities	(1,578,752)			(991,097)
Stockholders’ equity:
Common stock	0			0
Paid-in capital	(4,432,634)			(2,177,224)
Accumulated other comprehensive loss	48,548			53,783
(Accumulated deficit) retained earnings	(145,542)			(542,413)
Total stockholders’ equity	(4,529,628)			(2,665,854)
Total liabilities and stockholders’ equity	$ (6,108,380)			$ (3,656,951)

CONDENSED CONSOLIDATING FINAN_4

CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Statements of Operations) (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Total revenues	$ 285,175,000			$ 360,962,000			$ 1,064,747,000	$ 939,094,000
Costs and expenses:
Lease operating expenses	22,473,000			22,325,000			64,668,000	64,143,000
Production taxes	6,565,000			9,348,000			22,584,000	23,861,000
Midstream gathering and processing expenses	78,435,000			78,913,000			220,732,000	214,546,000
Depreciation, depletion and amortization	163,270,000			119,915,000			406,654,000	352,848,000
Impairment of oil and natural gas properties	571,442,000			0			571,442,000	0
General and administrative expenses	14,659,000			15,848,000			39,482,000	42,955,000
Accretion expense	747,000			1,037,000			3,173,000	3,056,000
Total costs and expenses	857,591,000			247,386,000			1,328,735,000	701,409,000
(LOSS) INCOME FROM OPERATIONS	(572,416,000)			113,576,000			(263,988,000)	237,685,000
OTHER EXPENSE (INCOME):
Interest expense	34,095,000			33,253,000			103,095,000	100,922,000
Interest income	(338,000)			(92,000)			(649,000)	(162,000)
Gain on sale of equity method investments	0			(2,733,000)			0	(124,768,000)
Gain on debt extinguishment	(23,600,000)			0			(23,600,000)	0
(Income) loss from equity method investments and investments in subsidiaries	43,082,000			(12,858,000)			164,391,000	(35,282,000)
Other expense	3,194,000			856,000			3,757,000	485,000
Total other (income) expense	56,433,000			18,426,000			246,994,000	(58,805,000)
LOSS BEFORE INCOME TAXES	(628,849,000)			95,150,000			(510,982,000)	296,490,000
INCOME TAX BENEFIT	(144,047,000)			0			(323,378,000)	(69,000)
NET LOSS	(484,802,000)	$ 234,956,000	$ 62,242,000	95,150,000	$ 111,319,000	$ 90,090,000	(187,604,000)	296,559,000
Parent
OTHER EXPENSE (INCOME):
Gain on debt extinguishment	(23,600,000)						(23,600,000)
Guarantors
OTHER EXPENSE (INCOME):
Gain on debt extinguishment	0						0
Non-Guarantors
OTHER EXPENSE (INCOME):
Gain on debt extinguishment	0						0
Reportable legal entities | Parent
Revenues:
Total revenues	27,358,000			235,683,000			493,895,000	596,018,000
Costs and expenses:
Lease operating expenses	(231,000)			16,502,000			26,918,000	46,926,000
Production taxes	36,000			4,505,000			6,117,000	13,309,000
Midstream gathering and processing expenses	0			54,397,000			71,420,000	152,605,000
Depreciation, depletion and amortization	2,686,000			119,914,000			201,250,000	352,846,000
Impairment of oil and natural gas properties	0						0
General and administrative expenses	27,218,000			16,314,000			56,195,000	45,100,000
Accretion expense	0			812,000			1,389,000	2,397,000
Total costs and expenses	29,709,000			212,444,000			363,289,000	613,183,000
(LOSS) INCOME FROM OPERATIONS	(2,351,000)			23,239,000			130,606,000	(17,165,000)
OTHER EXPENSE (INCOME):
Interest expense	35,105,000			34,254,000			105,364,000	103,310,000
Interest income	(187,000)			(86,000)			(454,000)	(144,000)
Gain on sale of equity method investments				(2,733,000)				(28,349,000)
(Income) loss from equity method investments and investments in subsidiaries	616,348,000			(104,226,000)			560,883,000	(387,991,000)
Other expense	(1,168,000)			880,000			(605,000)	(481,000)
Total other (income) expense	626,498,000			(71,911,000)			641,588,000	(313,655,000)
LOSS BEFORE INCOME TAXES	(628,849,000)			95,150,000			(510,982,000)	296,490,000
INCOME TAX BENEFIT	(144,047,000)			0			(323,378,000)	(69,000)
NET LOSS	(484,802,000)			95,150,000			(187,604,000)	296,559,000
Reportable legal entities | Guarantors
Revenues:
Total revenues	257,817,000			125,279,000			570,852,000	343,076,000
Costs and expenses:
Lease operating expenses	22,704,000			5,823,000			37,750,000	17,217,000
Production taxes	6,529,000			4,843,000			16,467,000	10,552,000
Midstream gathering and processing expenses	78,435,000			24,516,000			149,312,000	61,941,000
Depreciation, depletion and amortization	160,418,000			1,000			205,183,000	2,000
Impairment of oil and natural gas properties	571,442,000						571,442,000
General and administrative expenses	(12,675,000)			(467,000)			(16,933,000)	(2,148,000)
Accretion expense	747,000			225,000			1,784,000	659,000
Total costs and expenses	827,600,000			34,941,000			965,005,000	88,223,000
(LOSS) INCOME FROM OPERATIONS	(569,783,000)			90,338,000			(394,153,000)	254,853,000
OTHER EXPENSE (INCOME):
Interest expense	(1,010,000)			(1,001,000)			(2,269,000)	(2,388,000)
Interest income	(151,000)			(6,000)			(195,000)	(18,000)
Gain on sale of equity method investments				0				(96,419,000)
(Income) loss from equity method investments and investments in subsidiaries	0			(1,000)			0	(694,000)
Other expense	3,362,000			(24,000)			3,362,000	(34,000)
Total other (income) expense	2,201,000			(1,032,000)			898,000	(99,553,000)
LOSS BEFORE INCOME TAXES	(571,984,000)			91,370,000			(395,051,000)	354,406,000
INCOME TAX BENEFIT	0			0			0	0
NET LOSS	(571,984,000)			91,370,000			(395,051,000)	354,406,000
Reportable legal entities | Non-Guarantors
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 expenses	0			0			0	0
Depreciation, depletion and amortization	166,000			0			221,000	0
Impairment of oil and natural gas properties	0						0
General and administrative expenses	116,000			1,000			220,000	3,000
Accretion expense	0			0			0	0
Total costs and expenses	282,000			1,000			441,000	3,000
(LOSS) INCOME FROM OPERATIONS	(282,000)			(1,000)			(441,000)	(3,000)
OTHER EXPENSE (INCOME):
Interest expense	0			0			0	0
Interest income	0			0			0	0
Gain on sale of equity method investments				0				0
(Income) loss from equity method investments and investments in subsidiaries	40,000			275,000			379,000	833,000
Other expense	0			0			0	0
Total other (income) expense	40,000			275,000			379,000	833,000
LOSS BEFORE INCOME TAXES	(322,000)			(276,000)			(820,000)	(836,000)
INCOME TAX BENEFIT	0			0			0	0
NET LOSS	(322,000)			(276,000)			(820,000)	(836,000)
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 expenses	0			0			0	0
Depreciation, depletion and amortization	0			0			0	0
Impairment of oil and natural gas properties	0						0
General and administrative expenses	0			0			0	0
Accretion expense	0			0			0	0
Total costs and expenses	0			0			0	0
(LOSS) INCOME FROM OPERATIONS	0			0			0	0
OTHER EXPENSE (INCOME):
Interest expense	0			0			0	0
Interest income	0			0			0	0
Gain on sale of equity method investments				0				0
Gain on debt extinguishment	0						0
(Income) loss from equity method investments and investments in subsidiaries	(573,306,000)			91,094,000			(396,871,000)	352,570,000
Other expense	1,000,000			0			1,000,000	1,000,000
Total other (income) expense	(572,306,000)			91,094,000			(395,871,000)	353,570,000
LOSS BEFORE INCOME TAXES	572,306,000			(91,094,000)			395,871,000	(353,570,000)
INCOME TAX BENEFIT	0			0			0	0
NET LOSS	$ 572,306,000			$ (91,094,000)			$ 395,871,000	$ (353,570,000)

CONDENSED CONSOLIDATING FINAN_5

CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Statements of Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Financial Statements, Captions [Line Items]
Net loss	$ (484,802)	$ 234,956	$ 62,242	$ 95,150	$ 111,319	$ 90,090	$ (187,604)	$ 296,559
Foreign currency translation adjustment	(2,064)			3,052			5,347	(5,815)
Other comprehensive (loss) income	(2,064)	$ 3,610	$ 3,801	3,052	$ (3,364)	$ (5,503)	5,347	(5,815)
Comprehensive (loss) income	(486,866)			98,202			(182,257)	290,744
Reportable legal entities | Parent
Condensed Financial Statements, Captions [Line Items]
Net loss	(484,802)			95,150			(187,604)	296,559
Foreign currency translation adjustment	(2,064)			3,052			5,347	(5,815)
Other comprehensive (loss) income	(2,064)			3,052			5,347	(5,815)
Comprehensive (loss) income	(486,866)			98,202			(182,257)	290,744
Reportable legal entities | Guarantors
Condensed Financial Statements, Captions [Line Items]
Net loss	(571,984)			91,370			(395,051)	354,406
Foreign currency translation adjustment	(43)			103			112	(70)
Other comprehensive (loss) income	(43)			103			112	(70)
Comprehensive (loss) income	(572,027)			91,473			(394,939)	354,336
Reportable legal entities | Non-Guarantors
Condensed Financial Statements, Captions [Line Items]
Net loss	(322)			(276)			(820)	(836)
Foreign currency translation adjustment	(2,021)			2,949			5,235	(5,745)
Other comprehensive (loss) income	(2,021)			2,949			5,235	(5,745)
Comprehensive (loss) income	(2,343)			2,673			4,415	(6,581)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net loss	572,306			(91,094)			395,871	(353,570)
Foreign currency translation adjustment	2,064			(3,052)			(5,347)	5,815
Other comprehensive (loss) income	2,064			(3,052)			(5,347)	5,815
Comprehensive (loss) income	$ 574,370			$ (94,146)			$ 390,524	$ (347,755)

CONDENSED CONSOLIDATING FINAN_6

CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Cash Flows) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 617,355	$ 630,797
Net cash provided by (used in) investing activities	(638,648)	(554,586)
Net cash (used in) provided by financing activities	(20,880)	(51,197)
Net (decrease) increase in cash, cash equivalents and restricted cash	(42,173)	25,014
Cash, cash equivalents and restricted cash at beginning of period	52,297	99,557
Cash, cash equivalents and restricted cash at end of period	10,124	124,571
Reportable legal entities | Parent
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(7,604)	427,351
Net cash provided by (used in) investing activities	9,178	(354,848)
Net cash (used in) provided by financing activities	(20,880)	(51,197)
Net (decrease) increase in cash, cash equivalents and restricted cash	(19,306)	21,306
Cash, cash equivalents and restricted cash at beginning of period	25,585	67,908
Cash, cash equivalents and restricted cash at end of period	6,279	89,214
Reportable legal entities | Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	621,511	203,446
Net cash provided by (used in) investing activities	(644,507)	(199,738)
Net cash (used in) provided by financing activities	0	0
Net (decrease) increase in cash, cash equivalents and restricted cash	(22,996)	3,708
Cash, cash equivalents and restricted cash at beginning of period	26,711	31,649
Cash, cash equivalents and restricted cash at end of period	3,715	35,357
Reportable legal entities | Non-Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	3,445	(1)
Net cash provided by (used in) investing activities	(3,751)	(2,318)
Net cash (used in) provided by financing activities	435	2,319
Net (decrease) increase in cash, cash equivalents and restricted cash	129	0
Cash, cash equivalents and restricted cash at beginning of period	1	0
Cash, cash equivalents and restricted cash at end of period	130	0
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	3	1
Net cash provided by (used in) investing activities	432	2,318
Net cash (used in) provided by financing activities	(435)	(2,319)
Net (decrease) increase in cash, cash equivalents and restricted cash	0	0
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	$ 0	$ 0

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) bbl in Thousands	1 Months Ended
	Oct. 31, 2019MMBTU$ / MMBTUbbl	Dec. 31, 2018MMBTU$ / MMBTU
2019
Subsequent Event [Line Items]
Daily volume (in MMBtu)		100,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU		3.05
2019 | Subsequent Event
Subsequent Event [Line Items]
Daily Volume (Bbls/day) | bbl	1
Daily volume (in MMBtu)	120,000
2020 | Subsequent Event
Subsequent Event [Line Items]
Daily volume (in MMBtu)	28,000
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU	2.85