Legacy Reserves 10-K22 Mar 192018 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2018	Mar. 20, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Legacy Reserves Inc.
Entity Central Index Key	0001735828
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		114,810,671
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 452.5

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash	$ 1,098	$ 1,246
Accounts receivable, net:
Oil and natural gas	56,615	62,755
Joint interest owners	15,370	27,422
Fair value of derivatives (Notes 10 and 11)	66,662	13,424
Prepaid expenses and other current assets	11,347	7,757
Total current assets	151,092	112,604
Oil and natural gas properties, at cost:
Proved oil and natural gas properties using the successful efforts method of accounting	3,471,456	3,529,971
Unproved properties	19,863	28,023
Accumulated depletion, depreciation, amortization and impairment	(2,177,006)	(2,204,638)
Total oil and natural gas properties, net	1,314,313	1,353,356
Other property and equipment, net of accumulated depreciation and amortization of $12,323 and $11,467, respectively	2,456	2,961
Operating rights, net of amortization of $6,123 and $5,765, respectively	894	1,251
Fair value of derivatives (Notes 10 and 11)	3,135	14,099
Other assets	3,041	8,811
Total assets	1,474,931	1,493,082
Current liabilities:
Current debt, net (Note 3)	856,646	0
Accounts payable	11,227	13,093
Accrued oil and natural gas liabilities (Note 1)	98,886	81,318
Fair value of derivatives (Notes 10 and 11)	0	18,013
Asset retirement obligation (Note 13)	3,938	3,214
Other (Notes 10 and 15)	13,953	29,172
Total current liabilities	984,650	144,810
Long-term debt (Note 3)	432,923	1,346,769
Asset retirement obligation (Note 13)	248,796	271,472
Fair value of derivatives (Notes 10 and 11)	550	1,075
Other long-term liabilities	643	643
Total liabilities	1,667,562	1,764,769
Commitments and contingencies (Note 8)
Stockholders'/Partners’ equity (deficit):
Limited partners' deficit - 72,594,620 units issued and outstanding at December 31, 2017	0	(531,794)
General partner’s deficit (approximately 0.02%)	0	(160)
Common stock, $0.01 par value; 945,000,000 shares authorized, 109,442,278 shares outstanding at December 31, 2018	1,094	0
Additional paid-in capital	24,752	0
Accumulated deficit	(218,477)	0
Stockholders' Equity	(192,631)
Total stockholders’/partners' deficit	271,687	(271,687)
Total liabilities and stockholders'/partners’ deficit	1,474,931	1,493,082
Incentive distribution equity - 100,000 units issued and outstanding at December 31, 2017
Stockholders'/Partners’ equity (deficit):
Incentive distribution equity - 100,000 units issued and outstanding at December 31, 2017	0	30,814
Series A Preferred equity - 2,300,000 units issued and outstanding at December 31, 2017
Stockholders'/Partners’ equity (deficit):
Preferred equity	0	55,192
Series B Preferred equity - 7,200,000 units issued and outstanding at December 31, 2017
Stockholders'/Partners’ equity (deficit):
Preferred equity	$ 0	$ 174,261

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Other property and equipment, accumulated depreciation and amortization	$ 12,323	$ 11,467
Operating rights, amortization	$ 6,123	$ 5,765
Limited partners' equity, units issued (in shares)		72,594,620
Limited partners' equity, units outstanding (in shares)		72,594,620
General partner's equity, percent	0.02%
Common stock, par value (in USD per share)	$ 0.01
Common stock, shares authorized (in shares)	945,000,000
Common stock, shares outstanding (in shares)	109,442,278
Incentive Distribution Equity
Incentive distribution equity, units issued (in shares)		100,000
Incentive distribution equity, units outstanding (in shares)		100,000
Series A Preferred Equity
Preferred equity, units issued (in shares)		2,300,000
Preferred equity, units outstanding (in shares)		2,300,000
Series B Preferred Equity
Preferred equity, units issued (in shares)		7,200,000
Preferred equity, units outstanding (in shares)		7,200,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Revenues	$ 554,861	$ 436,301	$ 314,357
Expenses:
Oil and natural gas production	200,285	183,219	179,333
Production and other taxes	29,532	19,825	14,267
General and administrative	73,039	49,372	43,639
Depletion, depreciation, amortization and accretion	159,998	126,938	150,414
Impairment of long-lived assets	67,978	37,283	61,796
Loss (gain) on disposal of assets	(23,803)	1,606	(50,095)
Total expenses	507,029	418,243	399,354
Operating income (loss)	47,832	18,058	(84,997)
Other income (expense):
Interest income	36	64	67
Interest expense (Notes 3, 10 and 11)	(117,008)	(89,206)	(79,060)
Gain on extinguishment of debt	66,066	0	150,802
Equity in income of equity method investees	(19)	17	0
Net gains (losses) on commodity derivatives (Notes 10 and 11)	49,172	17,776	(41,224)
Other	722	792	(179)
Income (loss) before income taxes	46,801	(52,499)	(54,591)
Income tax expense	(2,968)	(1,398)	(1,229)
Net Income (loss)	$ 43,833	$ (53,897)	$ (55,820)
Basic and diluted loss per unit (in dollars per share)	$ 0.42	$ (0.54)	$ (0.57)
Weighted average number of units used in computing net loss per unit —
Basic and diluted (in shares)	105,087	100,049	98,249
Oil Sales
Revenues:
Revenues	$ 375,444	$ 239,448	$ 152,507
Natural Gas Liquids Sales
Revenues:
Revenues	27,750	24,796	15,406
Natural Gas Sales
Revenues:
Revenues	$ 151,667	$ 172,057	$ 146,444

Consolidated Statements of Stoc

Consolidated Statements of Stockholders'/Unitholders' Deficit - USD ($) shares in Thousands, $ in Thousands	Total	Non-employee directors	Common Stock	Common StockNon-employee directors	Additional Paid-in Capital	Additional Paid-in CapitalNon-employee directors	Acc. Deficit	Preferred EquitySeries A Preferred Equity	Preferred EquitySeries B Preferred Equity	Incentive Distribution Equity	Partners' DeficitLimited Partner	Partners' DeficitLimited PartnerNon-employee directors	Partners' DeficitGeneral Partner
Partners' equity, beginning balance (in shares) at Dec. 31, 2015								2,300	7,200	100	68,950
Partners' equity, beginning balance at Dec. 31, 2015								$ 55,192	$ 174,261	$ 30,814	$ (439,811)		$ (133)
Increase (Decrease) in Partners' Capital [Roll Forward]
Unit-based compensation (in shares)												237
Unit-based compensation											$ 6,252	$ 614
Vesting of restricted and phantom units (in shares)											150
Units issued in exchange for retirement of debt (in shares)											2,719
Units issued in exchange for retirement of debt											$ 6,607
Distributions to unitholders											(55)
Income/(loss)	$ (55,820)										$ (55,807)		(13)
Partners' equity, ending balance (in shares) at Dec. 31, 2016								2,300	7,200	100	72,056
Partners' equity, ending balance at Dec. 31, 2016								$ 55,192	$ 174,261	$ 30,814	$ (482,200)		(146)
Shareholders' equity, beginning balance (in units) at Dec. 31, 2015			0
Shareholders' equity, beginning balance at Dec. 31, 2015	0		$ 0		$ 0		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted and phantom units (in shares)											150
Income/(loss)	(55,820)										$ (55,807)		(13)
Shareholders' equity, ending balance (in units) at Dec. 31, 2016			0
Shareholders' equity, ending balance at Dec. 31, 2016	0		$ 0		0		0
Increase (Decrease) in Partners' Capital [Roll Forward]
Unit-based compensation (in shares)												287
Unit-based compensation											$ 3,703	$ 586
Vesting of restricted and phantom units (in shares)											252
Income/(loss)	(53,897)										$ (53,883)		(14)
Partners' equity, ending balance (in shares) at Dec. 31, 2017								2,300	7,200	100	72,595
Partners' equity, ending balance at Dec. 31, 2017	(271,687)							$ 55,192	$ 174,261	$ 30,814	$ (531,794)		(160)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted and phantom units (in shares)											252
Income/(loss)	(53,897)										$ (53,883)		(14)
Shareholders' equity, ending balance (in units) at Dec. 31, 2017			0
Shareholders' equity, ending balance at Dec. 31, 2017	0		$ 0		0		0
Increase (Decrease) in Partners' Capital [Roll Forward]
Unit-based compensation (in shares)												60
Unit-based compensation											$ 3,753	$ 522
Vesting of restricted and phantom units (in shares)			1,550								339
Units issued in exchange for Standstill Fee (in shares)											3,800
Units issued in exchange for Standstill Fee											$ 5,928
Corporate Reorganization (in units)			104,437					(2,300)	(7,200)	(100)	(76,794)
Corporate Reorganization	(264,583)		$ 1,060		(3,333)		(262,310)	$ (55,192)	$ (174,261)	$ (30,814)	$ 521,591		160
Income/(loss)	43,833						43,833				$ 0		0
Partners' equity, ending balance (in shares) at Dec. 31, 2018								0	0	0	0
Partners' equity, ending balance at Dec. 31, 2018	271,687							$ 0	$ 0	$ 0	$ 0		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Units issued to Legacy Board of Directors for services (in shares)				33
Units issued to Legacy Board of Directors for services		$ 162				$ 162
Unit-based compensation	4,108				4,108
Vesting of restricted and phantom units (in shares)			1,550								339
Debt exchange (in shares)			3,422
Debt exchange	23,849		$ 34		23,815
Corporate Reorganization (in units)			104,437					(2,300)	(7,200)	(100)	(76,794)
Corporate Reorganization	(264,583)		$ 1,060		(3,333)		(262,310)	$ (55,192)	$ (174,261)	$ (30,814)	$ 521,591		160
Income/(loss)	43,833						43,833				$ 0		$ 0
Shareholders' equity, ending balance (in units) at Dec. 31, 2018			109,442
Shareholders' equity, ending balance at Dec. 31, 2018	$ (192,631)		$ 1,094		$ 24,752		$ (218,477)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Income/(loss)		$ 43,833	$ (53,897)	$ (55,820)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depletion, depreciation, amortization and accretion		159,998	126,938	150,414
Amortization of debt discount and issuance costs		20,604	7,657	10,319
Gain on extinguishment of debt		(66,066)	0	(150,802)
Impairment of long-lived assets		67,978	37,283	61,796
(Gain) loss on derivatives		(49,099)	(19,711)	40,679
Equity in income of equity method investees		19	(17)	0
Unit-based compensation		6,619	6,011	7,035
Loss (gain) on disposal of assets		(23,803)	1,606	(50,095)
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, oil and natural gas		6,140	(19,563)	(9,248)
(Increase) decrease in accounts receivable, joint interest owners		12,039	(4,006)	1,964
Decrease in accounts receivable, other		12	0	84
(Increase) decrease in other assets		2,157	3	2,666
Increase (decrease) in accounts payable		(1,865)	4,001	(4,489)
Increase (decrease) in accrued oil and natural gas liabilities		9,540	1,891	2,675
Increase (decrease) in other liabilities		(12,165)	11,599	(3,882)
Total adjustments		132,108	153,692	59,116
Net cash provided by (used in) operating activities		175,941	99,795	3,296
Cash flows from investing activities:
Investment in oil and natural gas properties		(227,855)	(313,898)	(41,496)
Proceeds from sale of assets		54,968	11,099	97,416
Investment in other equipment		(406)	(593)	(436)
Corporate Reorganization		(3,120)	0	0
Net cash settlements on commodity derivatives		(11,715)	24,156	64,505
Net cash (used in) provided by investing activities		(188,128)	(279,236)	119,989
Cash flows from financing activities:
Proceeds from long-term debt		659,626	538,000	266,000
Payments of long-term debt		(619,384)	(357,000)	(376,402)
Payments of debt issuance costs		(28,132)	(3,282)	(8,728)
Net cash provided by (used in) financing activities		12,110	177,718	(119,130)
Net (decrease) increase in cash		(77)	(1,723)	4,155
Cash and restricted cash, beginning of period	[1]	4,438	6,161	2,006
Cash and restricted cash, end of period	[1]	4,361	4,438	6,161
Non-Cash Investing and Financing Activities:
Asset retirement obligation costs and liabilities		65	39	1
Asset retirement obligations associated with property acquisitions		226	62	24
Asset retirement obligations associated with properties sold		(27,673)	(8,464)	(24,605)
Debt exchange		23,849	0	6,607
Change in accrued capital expenditures		8,029	26,179	0
Units issued in exchange for Standstill Agreement		5,928
Restricted cash		$ 3,300	$ 3,200	$ 3,600

[1]	(1) Inclusive of $3.3 million, $3.2 million, $3.6 million and of restricted cash as of December 31, 2018, 2017, 2016 respectively.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Organization, Basis of Presentation and Description of Business Unless the context requires otherwise or unless otherwise noted, all references to “Legacy Reserves,” “Legacy Inc.,” “Legacy,” the “Company,” “we,” “us,” “our” or like terms are to Legacy Reserves Inc. and its subsidiaries for the periods after September 20, 2018, the date the Corporate Reorganization was consummated (as defined below). For the periods prior to September 20, 2018, unless the context requires otherwise or unless otherwise noted, all references to “Legacy Reserves,” “Legacy LP,” “Legacy,” the “Company,” “we,” “us,” “our” or like terms are to Legacy Reserves LP and its subsidiaries. Legacy is an independent energy company engaged in the development, production and acquisition of oil and natural gas properties in the United States. Its current operations are focused on the horizontal development of unconventional plays in the Permian Basin and the cost-efficient management of shallow-decline oil and natural gas wells in the Permian Basin, East Texas, Rocky Mountain and Mid-Continent regions. The accompanying financial statements have been prepared on the accrual basis of accounting whereby revenues are recognized when earned, and expenses are recognized when incurred. (b) Going Concern Legacy has significant obligations and commitments coming due in the near term. The Credit Agreement (as defined in Note 3) matures on May 31, 2019 and as of December 31, 2018, Legacy had borrowings of $541.0 million and availability under the Credit Agreement of $32.9 million . In addition, Legacy received a temporary waiver under the Term Loan Credit Agreement (as defined in Note 3) of its requirement to deliver fiscal year 2018 audited financial statements without a "going concern" or like qualification or exception through May 31, 2019. Due to the short-term nature of this waiver and the anticipation that we will be in violation of this covenant upon expiry of the waiver, Legacy has determined that the total borrowings outstanding under the Term Loan Credit Agreement of $338.6 million are due in the near term and have thus recorded these as a current liability. Without additional sources of capital or a significant restructuring of its balance sheet, the maturity of the Credit Agreement raises substantial doubt about Legacy's ability to continue as a going concern, which means that Legacy may be unable to continue operations for the foreseeable future or realize assets and discharge liabilities in the ordinary course of operation.The consolidated financial statements do not include any adjustments that might result from the outcome of the going concern uncertainty. In order to improve its liquidity position, Legacy is currently evaluating financial, transactional and other strategic alternatives. There can be no assurance that sufficient liquidity can be raised from any one or more of these transactions or that these transactions can be consummated within the period needed to meet our obligations. (c) Corporate Reorganization On September 20, 2018, we completed the transactions contemplated by the Amended and Restated Agreement and Plan of Merger (the “Merger Agreement”), dated July 9, 2018, by and among Legacy Inc., Legacy LP, Legacy Reserves GP, LLC (the “General Partner”) and Legacy Reserves Merger Sub LLC, a wholly owned subsidiary of Legacy Inc. (“Merger Sub”), and the GP Purchase Agreement, dated March 23, 2018, by and among Legacy Inc., the General Partner, Legacy LP, Lion GP Interests, LLC, Moriah Properties Limited, and Brothers Production Properties, Ltd., Brothers Production Company, Inc., Brothers Operating Company, Inc., J&W McGraw Properties, Ltd., DAB Resources, Ltd. and H2K Holdings, Ltd. (such transactions referred to herein collectively as the “Corporate Reorganization”). Upon the consummation of the Corporate Reorganization: • Legacy Inc., which prior to the Corporate Reorganization, was a wholly owned subsidiary of the General Partner, acquired all of the issued and outstanding limited liability company interests in the General Partner and became the sole member of the General Partner with the General Partner becoming a subsidiary of Legacy Inc.; and • Legacy LP merged with Merger Sub, with Legacy LP continuing as the surviving entity and as a subsidiary of Legacy Inc. (the “Merger”), the limited partner interests of Legacy LP, other than the incentive distribution units in Legacy LP, were exchanged for shares of Legacy Inc.’s common stock, par value $0.01 (“common stock”) and the general partner interest remained outstanding. The Corporate Reorganization was accounted for under ASC 805 as a combination of entities under common control. As such, the assets and liabilities of the Partnership were recognized at their carrying values in Legacy Inc. (d) Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. Legacy routinely assesses the financial strength of its customers. Bad debts are recorded based on an account-by-account review. Accounts are written off after all means of collection have been exhausted and potential recovery is considered remote. Legacy does not have any off-balance-sheet credit exposure related to its customers (see Note 12). (e) Oil and Natural Gas Properties Legacy accounts for oil and natural gas properties using the successful efforts method. Under this method of accounting, costs relating to the acquisition and development of proved areas are capitalized when incurred. The costs of development wells are capitalized whether productive or non-productive. Leasehold acquisition costs are capitalized when incurred. If proved reserves are found on an unproved property, leasehold cost is transferred to proved properties. Exploration dry holes are charged to expense when it is determined that no commercial reserves exist. Other exploration costs, including personnel costs, geological and geophysical expenses and delay rentals for oil and natural gas leases, are charged to expense when incurred. The costs of acquiring or constructing support equipment and facilities used in oil and gas producing activities are capitalized. Production costs are charged to expense as incurred and are those costs incurred to operate and maintain our wells and related equipment and facilities. Depreciation and depletion of producing oil and natural gas properties is recorded based on units of production. Acquisition costs of proved properties are amortized on the basis of all proved reserves, developed and undeveloped, and capitalized development costs (wells and related equipment and facilities) are amortized on the basis of proved developed reserves. As more fully described below, proved reserves are estimated annually by Legacy’s independent petroleum engineer, LaRoche Petroleum Consultants, Ltd. ("LaRoche"), and are subject to future revisions based on availability of additional information. Legacy’s in-house reservoir engineers prepare an updated estimate of reserves each quarter. Depletion is calculated each quarter based upon the latest estimated reserves data available. As discussed in Note 13, asset retirement costs are recognized when the asset is placed in service, and are amortized over proved developed reserves using the units of production method. Asset retirement costs are estimated by Legacy’s engineers using existing regulatory requirements and anticipated future inflation rates. Upon sale or retirement of complete fields of depreciable or depletable property, the book value thereof, less proceeds from sale or salvage value, is charged to income. On sale or retirement of an individual well the proceeds are credited to accumulated depletion and depreciation. Oil and natural gas properties are reviewed for impairment when facts and circumstances indicate that their carrying value may not be recoverable. Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. If net capitalized costs exceed estimated undiscounted future net cash flows, the measurement of impairment is based on estimated fair value, using estimated discounted future net cash flows. Significant inputs used to determine the fair values of proved properties include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in Legacy's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. For the year ended December 31, 2018 , Legacy recognized $58.7 million of impairment expense in 50 separate producing fields, due primarily to the further decline in oil and natural gas futures prices, increased expenses and well performance during the year ended December 31, 2018 , which decreased the expected future cash flows below the carrying value of the assets. For the year ended December 31, 2017 , Legacy recognized $37.3 million of impairment expense, in 47 separate producing fields, due primarily to the further decline in oil and natural gas futures prices, increased expenses and well performance during the year ended December 31, 2017 , which decreased the expected future cash flows below the carrying value of the assets. For the year ended December 31, 2016 , Legacy recognized $61.8 million of impairment expense, due primarily to well performance and the further decline in commodity prices during the year ended December 31, 2016, which decreased the expected future cash flows below the carrying value of the assets. Unproven properties that are individually significant are assessed for impairment and if considered impaired are charged to expense when such impairment is deemed to have occurred. Legacy recognized $9.3 million of impairment of unproven properties during the year ended December 31, 2018 . Legacy did not recognize impairment expense on unproved properties during the years ended December 31, 2017 and 2016 . (f) Oil, NGLs and Natural Gas Reserve Quantities Legacy’s estimates of proved reserves are based on the quantities of oil, NGLs and natural gas that engineering and geological analyses demonstrate, with reasonable certainty, to be recoverable from established reservoirs in the future under current operating and economic parameters. LaRoche prepares a reserve and economic evaluation of all Legacy’s properties on a case-by-case basis utilizing information provided to it by Legacy and information available from state agencies that collect information reported to it by the operators of Legacy’s properties. The estimates of Legacy’s proved reserves have been prepared and presented in accordance with SEC rules and accounting standards. Reserves and their relation to estimated future net cash flows impact Legacy’s depletion and impairment calculations. As a result, adjustments to depletion and impairment are made concurrently with changes to reserve estimates. Legacy prepares its reserve estimates, and the projected cash flows derived from these reserve estimates, in accordance with SEC guidelines. The independent engineering firm described above adheres to the same guidelines when preparing the reserve report. The accuracy of Legacy’s reserve estimates is a function of many factors including the quality and quantity of available data, the interpretation of that data, the accuracy of various mandated economic assumptions, and the judgments of the individuals preparing the estimates. Legacy’s proved reserve estimates are a function of many assumptions, all of which could deviate significantly from actual results. As such, reserve estimates may materially vary from the ultimate quantities of oil, NGLs and natural gas eventually recovered. (g) Income Taxes Prior to consummation of the Corporate Reorganization on September 20, 2018, Legacy LP was treated as a partnership for federal and state income tax purposes, in which the taxable income or loss was passed through to its unitholders. Legacy LP was subject to Texas margin tax and certain of Legacy LP’s subsidiaries were c-corporations subject to federal and state income taxes. Therefore, with the exception of the state of Texas and certain subsidiaries, Legacy LP did not directly pay federal and state income taxes and recognition was not given to federal and state income taxes for its operations. Effective upon consummation of the Corporate Reorganization, Legacy Inc. became subject to federal and state income taxes as a c-corporation. As such, we account for income taxes, as required, under the liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and net operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in net income or loss in the period that includes the enactment date. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Our policy is to record interest and penalties relating to uncertain tax positions in income tax expense. At December 31, 2018 , we did not have any accrued liability for uncertain tax positions and do not anticipate recognition of any significant liabilities for uncertain tax positions during the next 12 months. Please see Note 16 for more information on Legacy's accounting for income taxes. (h) Derivative Instruments and Hedging Activities Legacy uses derivative financial instruments to achieve more predictable cash flows by reducing its exposure to oil and natural gas price fluctuations and interest rate changes. Legacy does not specifically designate derivative instruments as cash flow hedges, even though they reduce its exposure to changes in oil and natural gas prices and interest rates. Therefore, Legacy records the change in the fair market values of oil and natural gas derivatives in current earnings. Changes in the fair values of interest rate derivatives are recorded in interest expense (see Notes 10 and 11). (i) Use of Estimates Management of Legacy has made a number of estimates and assumptions relating to the reporting of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities to prepare these consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. Actual results could differ materially from those estimates. Estimates which are particularly significant to the consolidated financial statements include estimates of oil and natural gas reserves, valuation of derivatives, impairment of oil and natural gas properties, depreciation, depletion and amortization, asset retirement obligations and accrued revenues. (j) Revenue Recognition On January 1, 2018, Legacy adopted ASU No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”) using the modified retrospective method of transition applied to all contracts. ASU 2014-09 created ASC 606, Revenue from Contracts with Customers (ASC 606). Legacy enters into contracts with customers to sell its produced oil, natural gas and NGLs. Revenue attributable to these contracts is recognized in accordance with the five-step revenue recognition model prescribed in ASC 606. Specifically, revenue is recognized when Legacy’s performance obligations under these contracts are satisfied, which generally occurs when control of the oil, natural gas and NGLs transfers to the purchaser and collectability is reasonably assured. Given the nature of Legacy’s products sold, Legacy has concluded that control transfers to its customers at a point in time. In accordance with ASC 606, Legacy considers the following indicators of the transfer of control to determine the point in time at which control transfers to its customers: (i) Legacy has a present right to payment for the asset; (ii) the customer has legal title to the asset; (iii) Legacy has transferred physical possession of the asset; and (iv) the customer has the significant risks and rewards of ownership. Oil Sales Legacy's oil sales contracts are generally structured such that Legacy sells its oil production to the purchaser at a contractually specified delivery point at or near the wellhead. The crude oil production is priced on the delivery date based upon prevailing index prices less certain deductions related to oil quality and physical location. Legacy recognizes revenue when control transfers to the purchaser upon delivery at or near the wellhead based on the net price received from purchaser. Natural Gas and NGL Sales Under Legacy's gas processing contracts, Legacy delivers wet gas to a midstream processing entity at the wellhead or the inlet of the midstream processing entity’s system. The midstream processing entity processes the natural gas and remits proceeds to Legacy for the resulting sales of NGLs and residue gas. Under this contract structure, Legacy has determined that the midstream processing entity represents Legacy’s customer, and, consequently, Legacy recognizes revenue when control transfers to the midstream processing entity upon delivery. The amount of revenue recognized is based on the net amount of the proceeds received from the midstream processing entity, which is generally tied to the prevailing index prices for residue gas and NGLs less deductions for gathering, processing, transportation and other expenses. Under Legacy's dry gas sales that do not require processing, Legacy sells its natural gas production to third party purchasers at a contractually specified delivery point at or near the wellhead. Pricing provisions are tied to a market index, with certain deductions based on, among other factors, whether a well delivers to a gathering or transmission line, quality of natural gas, and prevailing supply and demand conditions. Legacy recognizes revenue when control transfers to its third party purchasers upon delivery of the natural gas based on the relevant index price net of deductions. Estimation To the extent actual product volumes and related prices are unavailable for a given reporting period because of timing or information not received from third parties, the expected sales volumes and prices for those properties are estimated and recorded as “Accounts receivable - oil and natural gas” in the accompanying consolidated balance sheets. Refer to Note 4 - Revenue from Contracts with Customer for additional information. Imbalances Natural gas imbalances occur when Legacy sells more or less than its entitled ownership percentage of total natural gas production. Any amount received in excess of its share is treated as a liability. If Legacy receives less than its entitled share, the underproduction is recorded as a receivable. Legacy did not have any significant natural gas imbalance positions as of December 31, 2018 , 2017 and 2016 . (k) Investments Undivided interests in oil and natural gas properties owned through joint ventures are consolidated on a proportionate basis. Investments in entities where Legacy exercises significant influence, but not a controlling interest, are accounted for by the equity method. Under the equity method, Legacy’s investments are stated at cost plus the equity in undistributed earnings and losses after acquisition. (l) Environmental Legacy is subject to extensive federal, state and local environmental laws and regulations. These laws, which are frequently changing, regulate the discharge of materials into the environment and may require Legacy to remove or mitigate the environmental effects of the disposal or release of petroleum or chemical substances at various sites. Environmental expenditures are expensed or capitalized depending on their future economic benefit. Expenditures that relate to an existing condition caused by past operations and that have no future economic benefits are expensed. Liabilities for expenditures of a non-capital nature are recorded when environmental assessment and/or remediation are probable, and the costs can be reasonably estimated. Such liabilities are generally undiscounted unless the timing of cash payments is fixed and readily determinable. (m) Income (Loss) Per Share Basic income (loss) per share amounts are calculated using the weighted average number of shares outstanding during each period. Diluted income (loss) per share also gives effect to dilutive unvested restricted shares (calculated based upon the treasury stock method) (see Note 14). In accordance with ASC 805, income (loss) per share amounts for historical periods have been recomputed to reflect shares issued in the Corporate Reorganization. (n) Segment Reporting Legacy’s management initially treats each new acquisition of oil and natural gas properties as a separate operating segment. Legacy aggregates these operating segments into a single segment for reporting purposes. (o) Share-Based Compensation Concurrent with its formation on March 15, 2006, a Long-Term Incentive Plan (“Legacy LP LTIP”) for Legacy was created. Due to Legacy’s history of cash settlements for option exercises unit appreciation rights ("UARs") and certain phantom unit awards, Legacy accounted for these awards under the liability method, which requires Legacy to recognize the fair value of each unit award at the end of each period. Expense or benefit is recognized as the fair value of the liability changes from period to period. Legacy accounted for executive phantom unit and restricted unit awards under the equity method. Pursuant to the terms of the Corporate Reorganization, the Legacy LP LTIP was terminated. On September 19, 2018, the Legacy Inc. 2018 Omnibus Incentive Plan (the "Legacy Inc, LTIP") was approved by the former unitholders of Legacy LP in connection wiht the Corporate Reorganization. Legacy accounts for the restricted stock units ("RSUs") under the equity method. Legacy’s shares outstanding, as reflected in the accompanying consolidated balance sheet at December 31, 2018 , do not include 7,302,809 shares related to unvested RSUs. (p) Accrued Oil and Natural Gas Liabilities Below are the components of accrued oil and natural gas liabilities as of December 31, 2018 and 2017 . December 31, 2018 2017 (In thousands) Accrued capital expenditures $ 24,690 $ 33,198 Accrued lease operating expense 41,227 18,179 Revenue payable to joint interest owners 22,750 18,510 Accrued ad valorem tax 5,255 5,807 Other 4,964 5,624 $ 98,886 $ 81,318 (q) Restricted Cash Restricted cash of $3.3 million and $3.2 million as of December 31, 2018 and 2017 , respectively, is recorded in the "Prepaid expenses and other current assets" line. The restricted cash amounts represent various deposits to secure the performance of contracts, surety bonds and other obligations incurred in the ordinary course of business. (r) Prior Year Financial Statement Presentation Certain prior year balances have been reclassified to conform to the current year presentation of balances as stated in this annual report on Form 10-K. (s) Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, "Leases" ("ASU 2016-02"). ASU 2016-02 establishes a right-of-use (ROU) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms at commencement longer than twelve months. Legacy engaged a third party consultant to assist with its implementation of ASU 2016-02. Leases will be classified as either finance or operating, with that classification affecting the pattern of expense recognition in the income statement. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Legacy will adopt ASU 2016-02 using a modified retrospective approach in the first quarter of 2019 (that is, the period of adoption). At transition, Legacy will utilize the package of practical expedients provided in ASU 2016-02 that allow companies, among other things, to not reassess contracts that commenced prior to adoption. In addition, Legacy expects to utilize the practical expedient to not evaluate land easements that existed or expired before the adoption of ASU 2016-02 and that were not previously accounted for as leases under currently effective lease accounting guidance. Legacy is evaluating the provisions of ASU 2016-02 and finalizing the impact it will have on its consolidated results of operations, financial position and financial disclosures. Legacy believes that the new guidance will impact its consolidated balance sheet due to the recognition of right-of-use assets and lease liabilities that are not recognized under currently effective guidance (for example, operating leases). The adjustments that will be required upon implementation of ASU 2016-02, which Legacy anticipates to be less than $15 million, have not been finalized. Legacy commonly enters into lease agreements in support of its operations for assets such as office space, vehicles, drilling rigs, compressors and other well equipment. In its efforts to determine the impact of ASU 2016-02, Legacy developed an implementation approach that included educating key stakeholders within the organization, analyzing systems reports to identify the types and volume of contracts that may meet the definition of a lease and performing a detailed review of material contracts identified through that analysis. Legacy is also implementing a financial lease accounting system solution to facilitate compliance with ASU 2016-02.

Fair Values of Financial Instru

Fair Values of Financial Instruments	12 Months Ended
Fair Values of Financial Instruments	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Values of Financial Instruments	Fair Values of Financial Instruments The estimated fair values of Legacy’s financial instruments approximate the carrying amounts except as discussed below: Debt. The carrying amount of the revolving long-term debt approximates fair value because Legacy’s current borrowing rate does not materially differ from market rates for similar bank borrowings. The carrying amount of the second lien term loan debt under Legacy’s term loan credit agreement approximates fair value because Legacy’s current borrowing rate does not materially differ from market rates for similar borrowings. The fair value of the 8% senior notes due 2020 (the "2020 Senior Notes"), the 6.625% senior notes due 2021 (the "2021 Senior Notes") and the 8% convertible senior notes due 2023 (the "2023 Convertible Notes") was $97.8 million , $57.9 million and $42.3 million , respectively, as of December 31, 2018 . As these valuations are based on unadjusted quoted prices in an active market, the fair values would be classified as Level 1. Derivatives. See Note 10 for discussion of process used in estimating the fair value of commodity price and interest rate derivatives. Fair Value Measurements Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are classified and disclosed in one of the following categories: Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Legacy considers active markets as those in which transactions for the assets or liabilities occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. This category includes those derivative instruments that Legacy values using observable market data. Substantially all of these inputs are observable in the marketplace throughout the term of the derivative instrument, can be derived from observable data, or are supported by observable levels at which transactions are executed in the marketplace. Instruments in this category include non-exchange traded derivatives such as over-the-counter commodity price swaps and collars and interest rate swaps as well as long-term incentive plan liabilities calculated using the Black-Scholes model to estimate the fair value as of the measurement date. Level 3: Measured based on prices or valuation models that require inputs that are both significant to the fair value measurement and less observable from objective sources (i.e. supported by little or no market activity). Legacy’s valuation models are primarily industry standard models that consider various inputs including: (a) quoted forward prices for commodities, (b) time value, and (c) current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Level 3 instruments currently are limited to Midland-Cushing crude oil differential swaps. Although Legacy utilizes third party broker quotes to assess the reasonableness of its prices and valuation techniques, Legacy does not have sufficient corroborating evidence to support classifying these assets and liabilities as Level 2. Financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. Legacy’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. Fair Value on a Recurring Basis The following table sets forth by level within the fair value hierarchy Legacy’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2018 and 2017 : December 31, 2018 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Total Fair Value Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Description (Level 1) (Level 2) (Level 3) (In thousands) Assets: Current Commodity derivatives $ — $ 69,288 $ — $ 69,288 $ (4,670 ) $ 64,618 Interest rate derivatives — 2,044 — 2,044 — 2,044 Noncurrent Commodity derivatives — 3,473 — 3,473 (338 ) 3,135 Interest rate derivatives — — — — — — Liabilities: Current Commodity derivatives — (4,670 ) — (4,670 ) 4,670 — Noncurrent Commodity derivatives — (888 ) — (888 ) 338 (550 ) $ — $ 69,247 $ — $ 69,247 $ — $ 69,247 December 31, 2017 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Total Fair Value Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Description (Level 1) (Level 2) (Level 3) (In thousands) Assets: Current Commodity derivatives $ — $ 19,792 $ — $ 19,792 $ (7,204 ) $ 12,588 Interest rate derivatives — 837 — 837 (1 ) 836 Noncurrent Commodity derivatives — 14,278 — 14,278 (1,460 ) 12,818 Interest rate derivatives — 1,281 — 1,281 1,281 Liabilities: Current Commodity derivatives — (21,027 ) (4,191 ) (25,218 ) 7,204 (18,014 ) Interest rate derivatives — (1 ) — (1 ) 1 — LTIP liability — (1,947 ) — (1,947 ) (1,947 ) Noncurrent Commodity derivatives — (1,637 ) (897 ) (2,534 ) 1,460 (1,074 ) Interest rate derivatives — — — $ — $ 11,576 $ (5,088 ) $ 6,488 $ — $ 6,488 Legacy estimates the fair values of its commodity swaps based on published forward commodity price curves for the underlying commodities as of the date of the estimate for those commodities for which published forward pricing is readily available. For those commodity derivatives for which forward commodity price curves are not readily available, Legacy estimates, with the assistance of third-party pricing experts, the forward curves as of the date of the estimate. Legacy validates the data provided by third parties by understanding the pricing models used, obtaining market values from other pricing sources, analyzing pricing data in certain situations and confirming, where applicable, that those securities trade in active markets. Legacy estimates the option value of puts and calls combined into hedges, including costless collars, three-way collars and enhanced swaps using an option pricing model which takes into account market volatility, market prices, contract parameters and discount rates based on published LIBOR rates and interest swap rates. Due to the lack of an active market for periods beyond one-month from the balance sheet date for Legacy's oil price differential swaps, Legacy has reviewed historical differential prices and known economic influences to estimate a reasonable forward curve of future pricing scenarios based upon these factors. In order to estimate the fair value of its interest rate swaps, Legacy uses a yield curve based on money market rates and interest rate swaps, extrapolates a forecast of future interest rates, estimates each future cash flow, derives discount factors to value the fixed and floating rate cash flows of each swap, and then discounts to present value all known (fixed) and forecasted (floating) swap cash flows. Curve building and discounting techniques used to establish the theoretical market value of interest bearing securities are based on readily available money market rates and interest swap market data. The determination of the fair values above incorporates various factors including the impact of Legacy's non-performance risk and the credit standing of the counterparties involved in Legacy’s derivative contracts. The risk of nonperformance by Legacy’s counterparties is mitigated by the fact that enters into derivative transactions with entities which Legacy's management believes are creditworthy. In addition, Legacy routinely monitors the creditworthiness of its counterparties. As the factors described above are based on significant assumptions made by management, these assumptions are the most sensitive to change. The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy: Significant Unobservable Inputs (Level 3) December 31, 2018 2017 2016 (In thousands) Beginning balance $ (5,088 ) $ 8 $ (4,493 ) Total gains (losses) 30,571 (5,073 ) 253 Settlements (22,379 ) (23 ) 4,248 Transfers (3,104 ) (a) — — Ending balance $ — $ (5,088 ) $ 8 Gains (losses) included in earnings relating to derivatives still held as of December 31, 2018, 2017 and 2016 $ — $ (5,088 ) $ 68 ____________________ (a) Due to the lack of a historical market, we have historically accounted for our Midland-to-Cushing crude oil differential swaps as Level 3. However, with recent widening differentials, an active market has been created in which quoted prices are readily observable. As such, we have determined that the inputs used to value these derivatives now classify as Level 2 and transferred the value of the derivatives into Level 2. During periods of market disruption, including periods of volatile oil and natural gas prices, rapid credit contraction or illiquidity, it may be difficult to value certain of the Legacy's derivative instruments if trading becomes less frequent and/or market data becomes less observable. There may be certain asset classes that were in active markets with observable data that become illiquid due to changes in the financial environment. In such cases, more derivative instruments may fall to Level 3 and thus require more subjectivity and management judgment. As such, valuations may include inputs and assumptions that are less observable or require greater estimation as well as valuation methods which are more sophisticated or require greater estimation thereby resulting in valuations with less certainty. Further, rapidly changing commodity and unprecedented credit and equity market conditions could materially impact the valuation of derivative instruments as reported within Legacy's consolidated financial statements and the period-to-period changes in value could vary significantly. Decreases in value may have a material adverse effect on Legacy's results of operations or financial condition. Fair Value on a Non-Recurring Basis Nonfinancial assets and liabilities measured at fair value on a non-recurring basis include certain nonfinancial assets and liabilities as may be acquired in a business combination, measurements of oil and natural gas property impairments, and the initial recognition of asset retirement obligations, for which fair value is used. These asset retirement obligation ("ARO") estimates are derived from historical costs as well as management’s expectation of future cost environments. As there is no corroborating market activity to support the assumptions used, Legacy has designated these measurements as Level 3. A reconciliation of the beginning and ending balances of Legacy’s ARO is presented in Note 13. Nonrecurring fair value measurements of proved oil and natural gas properties during the years ended December 31, 2018 and 2017 consist of adjustments of the carrying value oil and natural gas properties to their fair value of $43.9 million and $31.9 million , respectively. Legacy periodically reviews oil and natural gas properties for impairment when facts and circumstances indicate that their carrying value may not be recoverable. During the year ended December 31, 2018 , Legacy incurred impairment charges of $58.7 million as oil and natural gas properties with a net cost basis of $102.6 million were written down to their fair value of $43.9 million . During the year ended December 31, 2017 , Legacy incurred impairment charges of $37.3 million as oil and natural gas properties with a net cost basis of $69.1 million were written down to their fair value of $31.8 million . In order to determine whether the carrying value of an asset is recoverable, Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. If the net capitalized cost exceeds the undiscounted future net cash flows, Legacy writes the net cost basis down to the discounted future net cash flows, which is management's estimate of fair value. Significant inputs used to determine the fair value include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices; and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in the Company's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. The inputs used by management for the fair value measurements utilized in this review include significant unobservable inputs, and therefore, the fair value measurements employed are classified as Level 3 for these types of assets. The remaining $9.3 million of impairment during the year ended December 31, 2018 represented impairment of unproved properties acquired since 2010 that are no longer viable for development.

Long-Term Debt

Long-Term Debt	12 Months Ended
Long-Term Debt	Dec. 31, 2018
Debt Disclosure [Abstract]
Long-Term Debt	Debt Debt consists of the following at December 31, 2018 and 2017 : December 31, 2018 2017 (In thousands) Current debt Credit Facility due 2019 $ 541,000 $ — Second Lien Term Loans due 2020 338,626 — Unamortized debt issuance costs (17,332 ) — Unamortized discount on Second Lien Term Loans (5,648 ) — Total current debt, net $ 856,646 $ — Long-term debt Credit Facility due 2019 $ — $ 499,000 Second Lien Term Loans due 2020 — 205,000 8% Senior Notes due 2020 208,885 232,989 6.625% Senior Notes due 2021 131,279 432,656 8% Convertible Senior Notes due 2023 128,103 — $ 468,267 $ 1,369,645 Unamortized discount on Senior Notes (31,517 ) (13,101 ) Unamortized debt issuance costs (3,827 ) (9,775 ) Total long-term debt, net $ 432,923 $ 1,346,769 Total debt, net $ 1,289,569 $ 1,346,769 Credit Facility On April 1, 2014, Legacy LP entered into a five years $1.5 billion secured revolving credit facility with Wells Fargo Bank, National Association, as administrative agent, Compass Bank, as syndication agent, UBS Securities LLC and U.S. Bank National Association, as co-documentation agents and the lenders party thereto (as amended, the “Credit Agreement”). On March 21, 2019, Legacy entered into the Twelfth Amendment to the Credit Agreement. Please see Note 18 for further discussion. Legacy's obligations under the Credit Agreement are secured by mortgages on over 95% of the total value of its oil and natural gas properties as well as a pledge of all of its ownership interests in its operating subsidiaries and Legacy's ownership interests in the General Partner. Concurrently with the Corporate Reorganization, the General Partner and Legacy Inc. provided guarantees of Legacy LP's obligations under the Credit Agreement. The amount available for borrowing at any one time is limited to the borrowing base and contains a $2 million sub-limit for letters of credit. The borrowing base was reaffirmed at $575 million as part of the fall 2018 redetermination. The borrowing base is subject to semi-annual redeterminations on or about April 1 and October 1 of each year, but no redeterminations are scheduled between now and maturity on April 1, 2019. Additionally, either Legacy or the lenders may, once during each calendar year, elect to redetermine the borrowing base between scheduled redeterminations. Legacy also has the right, once during each calendar year, to request the redetermination of the borrowing base upon the proposed acquisition of certain oil and natural gas properties where the purchase price is greater than 10% of the borrowing base then in effect. Any increase in the borrowing base requires the consent of all the lenders and any decrease in or maintenance of the borrowing base must be approved by the lenders holding at least 66-2/3% of the outstanding aggregate principal amounts of the loans or participation interests in letters of credit issued under the Credit Agreement. If the requisite lenders do not agree on an increase or decrease, then the borrowing base will be the highest borrowing base acceptable to the lenders holding 66-2/3% of the outstanding aggregate principal amounts of the loans or participation interests in letters of credit issued under the Credit Agreement so long as it does not increase the borrowing base then in effect. Prior to the Corporate Reorganization, the Credit Agreement contained a covenant that prohibited Legacy from paying distributions to its limited partners, including holders of its preferred units, if (i) Total Debt to EBITDA for the four fiscal quarters ending on the last day of the fiscal quarter immediately preceding the date of determination for which financial statements were available was greater than 4.0 to 1.0 or (ii) Legacy had unused lender commitments of less than or equal to 15% of the total lender commitments then in effect. Following the consummation of the Corporate Reorganization, the Credit Agreement contains a covenant that prohibits Legacy from paying dividends to its stockholders, if (i) Total Debt to EBITDA for the four fiscal quarters ending on the last day of the fiscal quarter immediately preceding the date of determination for which financial statements are available is greater than 3.0 to 1.0 or (ii) Legacy has unused lender commitments of less than or equal to 20% of the total lender commitments then in effect. The Credit Agreement also contains covenants that, among other things, require us to maintain specified ratios or conditions as follows: • as of any day, first lien debt to EBITDA for the four fiscal quarters ending on the last day of the fiscal quarter immediately preceding the date of determination for which financial statements are available to not be greater than 2.5 to 1.0 ; • as of the last day of any fiscal quarter, secured debt to EBITDA as of the last day of any fiscal quarter for the four fiscal quarters then ending of not more than 4.5 to 1.0 , beginning with the fiscal quarter ending on December 31, 2018; • as of the last day of any fiscal quarter, total EBITDA over the last four quarters to total interest expense over the last four quarters to be greater than 2.0 to 1.0 ; • consolidated current assets, as of the last day of the most recent quarter and including the unused amount of the total commitments, to consolidated current liabilities as of the last day of the most recent quarter of not less than 1.0 to 1.0 , excluding non-cash assets and liabilities under FASB Accounting Standards Codification 815, which includes the current portion of oil, natural gas and interest rate derivatives; and • as of the last day of any fiscal quarter, the ratio of (a) the sum of (i) the net present value using NYMEX forward pricing, discounted at 10 percent per annum, of Legacy’s proved developed producing oil and gas properties as reflected in the most recent reserve report delivered either July 1 or December 31 of each year, as the case may be (giving pro forma effect to material acquisitions or dispositions since the date of such reports) (“PDP PV-10”), (ii) the net mark to market value of Legacy’s commodity derivative agreements and (iii) Legacy’s cash and cash equivalents, in each case as of such date to (b) Secured Debt as of such day to be equal to or less than 1.0 to 1.0 . On September 14, 2018 and September 20, 2018, Legacy entered into the Tenth Amendment and Eleventh Amendment, respectively, to the Credit Agreement (the “Credit Agreement Amendments”). The Credit Agreement Amendments amend certain provisions set forth in the Credit Agreement to, among other items: • permit the issuance of the 2023 Convertible Notes; • provide that the 2023 Convertible Notes constitute debt that is permitted refinancing debt; • allow for the payment of a cash conversion incentive in connection with the early cashless conversion of the 2023 Convertible Notes into common stock; and • permit the redemption of certain senior notes or permitted refinancing debt of such senior notes with any combination of the following: (i) proceeds of certain permitted refinancing debt; (ii) net cash proceeds of any sale of equity interests (other than disqualified capital stock) of Legacy Inc.; and/or (iii) in exchange for equity interests (other than disqualified capital stock) of Legacy Inc. All capitalized terms not defined in the foregoing description have the meaning assigned to them in the Credit Agreement. As of December 31, 2018 , Legacy had outstanding borrowings of $541 million under the Credit Agreement at a weighted average interest rate of 5.44% and therefore had approximately $32.9 million of borrowing availability remaining. For the year ended December 31, 2018 , Legacy paid $27.3 million of interest expense on the Credit Agreement. As of December 31, 2018 , Legacy's ratio of current assets to current liabilities was less than 1.0 to 1.0 , in violation of a covenant contained in the Credit Agreement. On March 21, 2019, Legacy received waivers with respect to compliance with such covenant for the fiscal quarter ended December 31, 2018 and the requirement of delivery of fiscal year 2018 audited financials without a "going concern" qualification or exception. Legacy was in compliance with all other covenants contained in the Credit Agreement. Depending on future oil and natural gas prices, Legacy could breach certain financial covenants under its Credit Agreement, which would constitute a default under its Credit Agreement. Such default, if not remedied, would require a waiver from Legacy's lenders in order for it to avoid an event of default and, subject to certain limitations, subsequent acceleration of all amounts outstanding under its Credit Agreement and potential foreclosure on its oil and natural gas properties. If the lenders under Legacy's Credit Agreement were to accelerate the indebtedness under its Credit Agreement as a result of a default, such acceleration could cause a cross-default of all of its other outstanding indebtedness, including its Second Lien Term Loans (as defined below), its 8% Senior Notes due 2020 (the "2020 Senior Notes"), its 6.625% Senior Notes due 2021 (the "2021 Senior Notes") and its 8% Convertible Senior Notes due 2023 (the "2023 Convertible Notes" and, together with the 2020 Senior Notes and the 2021 Senior Notes, the “Senior Notes”), and permit the holders of such indebtedness to accelerate the maturities of such indebtedness. While no assurances can be made that, in the event of a covenant breach, such a waiver will be granted, Legacy believes the long-term global outlook for commodity prices and its efforts to date will be viewed positively by its lenders. Second Lien Term Loans On October 25, 2016, Legacy entered into a Second Lien Term Loan Credit Agreement (as amended, the "Term Loan Credit Agreement") among Legacy, as borrower, Cortland Capital Market Services LLC ("Cortland"), as administrative agent and second lien collateral agent, and the lenders party thereto, providing for term loans up to an aggregate principal amount of $300.0 million (the “Second Lien Term Loans”). On May 21, 2019, Legacy entered into the Seventh Amendment to the Term Loan Credit Agreement. Please see Note 18 for further discussion. The Second Lien Term Loans under the Term Loan Credit Agreement are issued with an upfront fee of 2% and bear interest at a rate of 12% per annum payable quarterly in cash. GSO Capital Partners L.P. (“GSO”) and certain funds and accounts managed, advised or sub-advised, by GSO are the initial lenders thereunder. The Term Loan Credit Agreement matures on August 31, 2021; provided that, if on July 1, 2020, Legacy has greater than or equal to a face amount of $15.0 million of Senior Notes that were outstanding on the date the Term Loan Credit Agreement was entered into or any other senior notes with a maturity date that is earlier than August 31, 2021, the Term Loan Credit Agreement will mature on August 1, 2020. The Second Lien Term Loans are secured on a second lien priority basis by the same collateral that secures Legacy's Credit Agreement and are unconditionally guaranteed on a joint and several basis by the same wholly owned subsidiaries of Legacy that are guarantors under the Credit Agreement. In addition, upon consummation of the Corporate Reorganization, the General Partner and Legacy Inc. became guarantors. As of December 31, 2018 , Legacy had approximately $338.6 million drawn under the Term Loan Credit Agreement. On December 31, 2017, Legacy entered into the Third Amendment to the Term Loan Credit Agreement (the "Third Amendment") among Legacy, as borrower, Cortland, as administrative agent and second lien collateral agent, and the lenders party thereto, including GSO and certain funds and accounts managed, advised or sub-advised by GSO, which, among other things, increased the maximum amount available for borrowing under the Second Lien Term Loans to $400.0 million , extended the availability of undrawn principal ( $61.4 million of availability as of December 31, 2018 ) to October 25, 2019 and relaxed the asset coverage ratio to 0.85 to 1.00 until the fiscal quarter ended December 31, 2018. The Third Amendment became effective on January 5, 2018. Prior to the Corporate Reorganization, the Term Loan Credit Agreement contained a covenant that prohibited Legacy from paying distributions to its limited partners, including holders of its preferred units, if (i) Total Debt to EBITDA for the four fiscal quarters ending on the last day of the fiscal quarter immediately preceding the date of determination for which financial statements were available was greater than 4.00 to 1.00 or (ii) Legacy had unused lender commitments of less than or equal to 15% of the total lender commitments then in effect. Following consummation of the Corporate Reorganization, the Term Loan Credit Agreement contains a covenant that prohibits Legacy from paying dividends to the stockholders, if (i) Total Debt to EBITDA for the four fiscal quarters ending on the last day of the fiscal quarter immediately preceding the date of determination for which financial statements are available is greater than 3.00 to 1.00 or (ii) Legacy has unused lender commitments of less than or equal to 20% of the total lender commitments then in effect. The Term Loan Credit Agreement also contains covenants that, among other things, require Legacy to: • not permit, as of the last day of any fiscal quarter, the ratio of the sum of (i) the net present value using NYMEX forward pricing of Legacy’s PDP PV-10, (ii) the net mark to market value of Legacy’s commodity derivative agreements and (iii) Legacy’s cash and cash equivalents to Secured Debt to be less than 0.85 to 1.00 until the fiscal quarter ended December 31, 2018 and 1.00 to 1.00 thereafter; and • not permit, as of the last day of any fiscal quarter beginning with the fiscal quarter ending December 31, 2018, Legacy’s ratio of Secured Debt as of such day to EBITDA for the four fiscal quarters then ending to be greater than 4.50 to 1.00. On September 14, 2018 and September 20, 2018, Legacy entered into the Fifth Amendment and Sixth Amendment, respectively, to the Term Loan Credit Agreement (the “Term Loan Amendments”). The Term Loan Amendments amend certain provisions set forth in the Term Loan Credit Agreement to, among other items: • permit the issuance of the 2023 Convertible Notes; • provide that the 2023 Convertible Notes constitute debt that is permitted refinancing debt; • allow for the payment of a cash conversion incentive in connection with the early cashless conversion of the 2023 Convertible Notes into common stock; and • permit the redemption of certain senior notes or permitted refinancing debt of such senior notes with any combination of the following: (i) proceeds of certain permitted refinancing debt; (ii) net cash proceeds of any sale of equity interests (other than disqualified capital stock) of Legacy Inc.; and/or (iii) in exchange for equity interests (other than disqualified capital stock) of Legacy Inc. At December 31, 2018 , Legacy was in compliance with all covenants contained in the Second Lien Term Loan Credit Agreement. For the year ended December 31, 2018 , Legacy incurred interest expense of $41.0 million under the Second Lien Term Loan Credit Agreement. 8% Senior Notes Due 2020 On December 4, 2012, Legacy and its 100% owned subsidiary Legacy Reserves Finance Corporation completed a private placement offering to eligible purchasers of an aggregate principal amount of $300.0 million of Legacy's 8% Senior Notes due 2020 (the "2020 Senior Notes"), which were subsequently registered through a public exchange offer that closed on January 8, 2014. The 2020 Senior Notes were issued at 97.848% of par. Legacy has the option to redeem the 2020 Senior Notes, in whole or in part, at par together with any accrued and unpaid interest, if any, to the date of redemption. Legacy may be required to offer to repurchase the 2020 Senior Notes at a purchase price of 101% of the principal amount, plus accrued and unpaid interest, if any, to the redemption date, in the event of a change of control as defined by the indenture. Legacy and Legacy Reserves Finance Corporation's obligations under the 2020 Senior Notes are guaranteed by its 100% owned subsidiaries Legacy Reserves Operating GP LLC, Legacy Reserves Operating LP, Legacy Reserves Services, Inc., Legacy Reserves Energy Services LLC, Dew Gathering LLC and Pinnacle Gas Treating LLC, which constitute all of Legacy's wholly-owned subsidiaries other than Legacy Reserves Finance Corporation. In the future, the guarantees may be released or terminated under the following circumstances: (i) in connection with any sale or other disposition of all or substantially all of the properties of the guarantor; (ii) in connection with any sale or other disposition of sufficient capital stock of the guarantor so that it no longer qualifies as Legacy's Restricted Subsidiary (as defined in the indenture); (iii) if designated to be an unrestricted subsidiary; (iv) upon legal defeasance, covenant defeasance or satisfaction and discharge of the indenture; (v) upon the liquidation or dissolution of the guarantor provided no default or event of default has occurred or is occurring; (vi) at such time the guarantor does not have outstanding guarantees of its, or any other guarantor's, other debt; or (vii) upon merging into, or transferring all of its properties to Legacy or another guarantor and ceasing to exist. Refer to Note 17 - Subsidiary Guarantors for further details on Legacy's guarantors. The indenture governing the 2020 Senior Notes limits Legacy's ability and the ability of certain of its subsidiaries to (i) sell assets; (ii) pay distributions on, repurchase or redeem equity interests or purchase or redeem Legacy's subordinated debt, provided that such subsidiaries may pay dividends to the holders of their equity interests (including Legacy) and Legacy may pay distributions to the holders of its equity interests subject to the absence of certain defaults, the satisfaction of a fixed charge coverage ratio test and certain other conditions; (iii) make certain investments; (iv) incur or guarantee additional indebtedness or issue preferred units; (v) create or incur certain liens; (vi) enter into agreements that restrict distributions or other payments from certain of its subsidiaries to Legacy; (vii) consolidate, merge or transfer all or substantially all of Legacy's assets; (viii) engage in certain transactions with affiliates; (ix) create unrestricted subsidiaries; and (x) engage in certain business activities. These covenants are subject to a number of important exceptions and qualifications. If at any time when the 2020 Senior Notes are rated investment grade by each of Moody's Investors Service, Inc. and Standard & Poor's Ratings Services and no Default (as defined in the indenture) has occurred and is continuing, many of such covenants will terminate and Legacy and its subsidiaries will cease to be subject to such covenants. Further, if the lenders under Legacy's Credit Agreement or Term Loan Credit Agreement were to accelerate the indebtedness under Legacy's Credit Agreement or Term Loan Credit Agreement as a result of a default, such acceleration could cause a cross-default of all of the 2020 Senior Notes and permit the holders of such notes to accelerate the maturities of such indebtedness. In connection with the exchange of approximately $21.0 million aggregate principal amount of 2020 Senior Notes for the same aggregate principal of the 2023 Convertible Notes and the issuance of 105,020 shares of Common Stock in September 2018, Legacy recognized a $1.4 million gain on extinguishment of debt, which consisted of the difference between (1) the face amount of the exchanged 2020 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the fair value of the new 2023 Convertible Notes. During the year ended December 31, 2018 , Legacy exchanged 1,000,000 shares of Common Stock for $3.1 million of face amount of its outstanding 2020 Senior Notes. Legacy treated the exchange as an extinguishment of debt. Accordingly, Legacy recognized a gain for the difference between (1) the face amount of the 2020 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the fair value of the units issued in the exchange based on the closing price on the date of exchange. During the year ended December 31, 2016, Legacy repurchased a face amount of $52.0 million of its 2020 Senior Notes on the open market. Legacy treated these repurchases as an extinguishment of debt. Accordingly, Legacy recognized a gain for the difference between (1) the face amount of the 2020 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the repurchase price. On June 1, 2016, Legacy exchanged 2,719,124 units representing limited partner interests in the Partnership for $15.0 million of face amount of its outstanding 2020 Senior Notes. Legacy treated this exchange as an extinguishment of debt. Accordingly, Legacy recognized a gain for the difference between (1) the face amount of the 2020 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the fair value of the units issued in the exchange based on the closing price on June 1, 2016. The indenture also includes customary events of default. As of the December 31, 2018 , the Company was in compliance with all covenants of the 2020 Senior Notes. Interest is payable on June 1 and December 1 of each year. 6.625% Senior Notes Due 2021 On May 28, 2013, Legacy and its 100% owned subsidiary Legacy Reserves Finance Corporation completed a private placement offering to eligible purchasers of an aggregate principal amount of $250 million of Legacy's 6.625% Senior Notes due 2021 (the "2021 Senior Notes"), which were subsequently registered through a public exchange offer that closed on March 18, 2014. The 2021 Senior Notes were issued at 98.405% of par. On May 13, 2014, Legacy and its 100% owned subsidiary Legacy Reserves Finance Corporation completed a private placement offering to eligible purchasers of an aggregate principal amount of an additional $300 million of the 6.625% 2021 Senior Notes. These 2021 Senior Notes were issued at 99% of par. The terms of the 2021 Senior Notes, including details related to Legacy's guarantors, are substantially identical to the terms of the 2020 Senior Notes with the exception of the maturity date, interest rate and redemption provisions noted below. Legacy will have the option to redeem the 2021 Senior Notes, in whole or in part, at par together with any accrued and unpaid interest, if any, to the date of redemption. Legacy may be required to offer to repurchase the 2021 Senior Notes at a purchase price of 101% of the principal amount, plus accrued and unpaid interest, if any, to the redemption date, in the event of a change of control as defined by the indenture. Legacy and Legacy Reserves Finance Corporation's obligations under the 2021 Senior Notes are guaranteed by the same parties and on the same terms as Legacy's 2020 Senior Notes discussed above. Further, if the lenders under Legacy's Credit Agreement or Term Loan Credit Agreement were to accelerate the indebtedness under Legacy's Credit Agreement or Term Loan Credit Agreement as a result of a default, such acceleration could cause a cross-default of all of the 2021 Senior Notes and permit the holders of such notes to accelerate the maturities of such indebtedness. As of December 31, 2018 , the Company was in compliance with all covenants of the 2021 Senior Notes. Interest is payable on June 1 and December 1 of each year. On September 20, 2018, in connection with the exchange of approximately $109.0 million aggregate principal amount of 2021 Senior Notes for the same aggregate principal of the 2023 Convertible Notes, Legacy recognized a $10.7 million gain on extinguishment of debt, which consisted of the difference between (1) the face amount of the exchanged 2021 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the fair value of the new 2023 Convertible Notes. During the year ended December 31, 2018 , Legacy exchanged 2,000,000 shares of Common Stock for $5.3 million of face amount of its outstanding 2020 Senior Notes. Legacy treated the exchange as an extinguishment of debt. Accordingly, Legacy recognized a gain for the difference between (1) the face amount of the 2020 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the fair value of the units issued in the exchange based on the closing price on the date of exchange. On December 31, 2017, Legacy entered into an agreement to repurchase a face amount of $187.1 million of its 2021 Senior Notes from certain holders in a single transaction. The transaction was funded on January 5, 2018 and will therefore be recognized in 2018. Legacy will treat this repurchase as an extinguishment of debt. Accordingly, Legacy will recognize a gain for the difference between (1) the face amount of the 2021 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the repurchase price. During the year ended December 31, 2016, Legacy repurchased a face amount of $117.3 million of its 2021 Senior Notes on the open market. Legacy treated these repurchases as an extinguishment of debt. Accordingly, Legacy recognized a gain for the difference between (1) the face amount of the 2021 Senior Notes repurchased net of the unamortized portion of both the original issuer's discount and issuance costs and (2) the repurchase price. For the year ended December 31, 2018 , Legacy paid $34.6 million of cash interest expense for the 2020 Senior Notes and 2021 Senior Notes. 8% Convertible Senior Notes Due 2023 ("2023 Convertible Notes") On September 20, 2018, the Issuers, completed private exchanges with certain holders of senior notes, pursuant to which the Issuers exchanged (i) $21.004 million aggregate principal amount of 2020 Senior Notes for $21.004 million aggregate principal amount of 2023 Convertible Notes and 105,020 shares of common stock and (ii) $109.0 million aggregate principal amount of 2021 Senior Notes for $109.0 million aggregate principal amount of 2023 Convertible Notes. The 2023 Convertible Notes were issued pursuant to an Indenture, dated as of September 20, 2018 (the “2023 Convertible Note Indenture”) Upon issuance, the Company separately accounted for the liability and equity components in accordance with Accounting Standards Codification 470-20. The initial fair value of the 2023 Convertible Notes in its entirety (inclusive of the equity component related to the conversion option) was estimated using observable inputs such as trades that occurred on the day of the transaction. The liability component was recorded at the estimated fair value of a similar debt instrument without the conversion feature. The difference between the aggregate principal amount of the 2023 Convertible Notes and the fair value of the liability component was recorded as a debt discount and is being amortized to interest expense over the term of the notes using the effective interest method. The fair value of the liability component of the 2023 Convertible Notes was estimated at $101.0 million , resulting in a debt discount of $29.0 million The equity component, representing the value of the conversion option, was computed by deducting the fair value of the liability component from the initial fair value of the 2023 Convertible Notes. The equity component was recorded in additional paid-in capital within stockholders’ equity and will not be remeasured as long as it continues to meet the conditions for equity classification. The 2023 Convertible Notes mature on September 20, 2023, unless earlier repurchased or redeemed by the Issuers or converted. The 2023 Convertible Notes are subject to redemption for cash, in whole or in part, at the Issuers’ option at a redemption price equal to 100% of the 2023 Convertible Notes to be redeemed, plus any accrued and unpaid interest. In addition, the Issuers are required to make an offer to holders of the 2023 Convertible Notes upon a change of control at a price equal to 101% , plus any accrued and unpaid interest, and an offer to holders of the 2023 Convertible Notes upon consummation by the Issuers or any restricted subsidiaries of certain asset sales at a price equal to 100% , plus any accrued and unpaid interest. The 2023 Convertible Notes are convertible into shares of common stock at an initial conversion rate of 166.6667 shares per $1,000 principal amount of 2023 Convertible Notes, which is equal to an initial conversion price of $6.00 per share of common stock (the "Conversion Price"). The 2023 Convertible Notes are convertible, at the option of the holders, into shares of common stock at any time from the date of issuance up until the close of business on the earlier of (i) the business day prior to the date of a mandatory conversion notice, (ii) with respect to a 2023 Convertible Note called for redemption, the business day immediately preceding the redemption date or (iii) the business day immediately preceding the maturity date. In addition, if a holder exercises its right to convert on or prior to September 19, 2019, such holder will receive an early conversion payment, in cash, per $1,000 principal amount as follows: Early Conversion Date Early Conversion Payment December 1, 2018 through May 31, 2019 $64.22 June 1, 2019 through September 19, 2019 $24.22 Subject to compliance with certain conditions, the Issuers have the right to mandatorily convert all of the 2023 Convertible Notes if the volume weighted average price of the common stock equals or exceeds the conversion price for at least 20 trading days (whether or not consecutive) during any period of 30 consecutive trading days commencing on or after the initial issuance date. The 2023 Convertible Notes are guaranteed by Legacy Inc., the General Partner, Legacy Reserves Operating GP LLC, Legacy Reserves Operating LP, Legacy Reserves Services LLC, Legacy Reserves Energy Services LLC, Dew Gathering LLC and Pinnacle Gas Treating LLC. The terms of the 2023 Convertible Notes, including the Guarantors, are substantially identical to the terms of the 2020 Senior Notes and 2021 Senior Notes with the exception of the interest rate, conversion and redemption provisions noted above. Additionally, if the lenders under Legacy's Credit Agreement or Term Loan Credit Agreement were to accelerate the indebtedness under Legacy's Credit Agreement or Term Loan Credit Agreement as a result of a default, such acceleration could cause a cross-default of all of the 2023 Senior Notes and permit the holders of such notes to accelerate the maturities of such indebtedness. During the year ended December 31, 2018 , certain holders of the 2023 Convertible Notes exercised their option to convert $1.9 million of face amount of 2023 Convertible Notes in exchange for 316,828 shares of common stock. Interest is payable on June 1 and December 1 of each year.

Impact of ASC 606 Adoption

Impact of ASC 606 Adoption	12 Months Ended
Impact of ASC 606 Adoption	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Impact of ASC 606 Adoption	mpact of ASC 606 Adoption On January 1, 2018, Legacy adopted ASU No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”) using the modified retrospective method of transition applied to all contracts. ASU 2014-09 created ASC 606 - Revenue from Contracts with Customers ("ASC 606"), which supersedes nearly all existing revenue recognition guidance under U.S. GAAP and includes a five step process to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. The impact of adoption on Legacy's current period results is as follows (in thousands): Twelve months ended December 31, 2018 Under ASC 606 Under ASC 605 Change (In thousands) Revenues: Oil Sales $ 375,444 $ 375,244 $ (200 ) Natural gas liquids (NGL) sales 27,750 27,232 (518 ) Natural gas sales 151,667 145,135 (6,532 ) $ 554,861 $ 547,611 $ (7,250 ) Costs and expenses: Oil and natural gas production 200,285 193,035 (7,250 ) Net income 43,833 43,833 $ — Partners' deficit, as of January 1, 2018 271,687 271,687 $ — The change to oil sales and a related change to oil production expense are due to the conclusion that Legacy transfers control of oil production to purchasers at or near the wellhead. As such, certain transportation expenses that are deducted from the sales price Legacy receives from the purchaser are presented net in revenue in accordance with ASC 606. This represents a change from Legacy's prior practice under ASC 605 of presenting those transportation costs gross as an oil and natural gas production expense. The change to natural gas and NGL sales and the related change to natural gas production expense are due to the conclusion that Legacy represents an agent in certain gas processing agreements with midstream entities in accordance with the control model in ASC 606. This represents a change from Legacy's previous conclusion utilizing the principal versus agent indicators under ASC 605 that Legacy acted as the principal in those arrangements. As a result, Legacy is required to present certain gathering and processing expenses net in natural gas and NGL sales under ASC 606. Revenue from Contracts with Customers Oil, NGL and natural gas sales revenues are generally recognized at the point in time that control of the product is transferred to the customer and collectability is reasonably assured. This generally occurs when oil or natural gas has been delivered to a pipeline or a tank lifting has occurred. A more detailed summary of the sale of each product type is included below. Oil Sales Legacy's oil sales contracts are generally structured such that Legacy sells its oil production to the purchaser at a contractually specified delivery point at or near the wellhead. The crude oil production is priced on the delivery date based upon prevailing index prices less certain deductions related to oil quality and physical location. Legacy recognizes revenue when control transfers to the purchaser upon delivery at the net price received from purchaser. NGL and Natural Gas Sales Under Legacy's gas processing contracts, Legacy delivers wet gas to a midstream processing entity at the wellhead or the inlet of the midstream processing entity’s system. The midstream processing entity processes the natural gas and remits proceeds to Legacy for the resulting sales of NGLs and residue gas. In these scenarios, Legacy evaluates whether it is the principal or the agent in the transaction. In virtually all of Legacy's gas processing contracts, Legacy has concluded that it is the agent, and the midstream processing entity is Legacy's customer. Accordingly, Legacy recognizes revenue upon delivery based on the net amount of the proceeds received from the midstream processing entity. Proceeds are generally tied to the prevailing index prices for residue gas and NGLs less deductions for gathering, processing, transportation and other expenses. Under Legacy's dry gas sales that do not require processing, Legacy sells its natural gas production to third party purchasers at a contractually specified delivery point at or near the wellhead. Pricing provisions are tied to a market index, with certain deductions based on, among other factors, whether a well delivers to a gathering or transmission line, quality of natural gas, and prevailing supply and demand conditions, so that the price of the natural gas fluctuates to remain competitive with other available natural gas supplies. Legacy recognizes revenue upon delivery of the natural gas to third party purchasers based on the relevant index price net of deductions. Imbalances Natural gas imbalances occur when Legacy sells more or less than its entitled ownership percentage of total natural gas production. Any amount received in excess of its share is treated as a liability. If Legacy receives less than its entitled share, the underproduction is recorded as a receivable. Legacy did not have any significant natural gas imbalance positions as of December 31, 2018, 2017 and 2016. Disaggregation of Revenue Legacy has identified three material revenue streams in its business: oil sales, NGL sales, and natural gas sales. Revenue attributable to each of Legacy's identified revenue streams is disaggregated in the table below. Twelve Months Ended December 31, 2018 (In thousands) Revenues: Oil sales $ 375,444 Natural gas liquids (NGL) sales 27,750 Natural gas sales 151,667 Total revenues $ 554,861 Significant Judgments Principal versus agent Legacy engages in various types of transactions in which midstream entities process its gas and subsequently market resulting NGLs and residue gas to third-party customers on Legacy's behalf, such as Legacy's percentage-of-proceeds and gas purchase contracts. These types of transactions require judgment to determine whether Legacy is the principal or the agent in the contract and, as a result, whether revenues are recorded gross or net. Transaction price allocated to remaining performance obligations A significant number of Legacy's product sales are short-term in nature with a contract term of one year or less. For those contracts, Legacy has utilized the practical expedient in ASC 606 that exempts it from disclosure of the transaction price allocated to remaining performance obligations if the performance obligation is part of a contract that has an original expected duration of one year or less. For Legacy's product sales that have a contract term greater than one year, Legacy has utilized the practical expedient in ASC 606 that states that it is not required to disclose the transaction price allocated to remaining performance obligations if the variable consideration is allocated entirely to a wholly unsatisfied performance obligation. Under these sales contracts, each unit of product represents a separate performance obligation; therefore future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required. Contract balances Under Legacy's product sales contracts, it is entitled to payment from purchasers once its performance obligations have been satisfied upon delivery of the product, at which point payment is unconditional and invoiced amounts are recorded as “Accounts receivable - oil and natural gas” in its consolidated balance sheet. To the extent actual volumes and prices of oil and natural gas are unavailable for a given reporting period because of timing or information not received from third parties, the expected sales volumes and prices for those properties are estimated and also recorded as “Accounts receivable - oil and natural gas” in the accompanying consolidated balance sheets. In this scenario, payment is also unconditional, as Legacy has satisfied its performance obligations through delivery of the relevant product. As a result, Legacy has concluded that its product sales do not give rise to contract assets or liabilities under ASC 606. Prior-period performance obligations Legacy records revenue in the month production is delivered to the purchaser. However, settlement statements for certain oil, natural gas and NGL sales may not be received for 30 to 60 days after the date production is delivered, and as a result, Legacy is required to estimate the amount of production that was delivered to the midstream purchaser and the price that will be received for the sale of the product. Additionally, to the extent actual volumes and prices of oil are unavailable for a given reporting period because of timing or information not received from third party purchasers, the expected sales volumes and prices for those barrels of oil are also estimated. Legacy records the differences between its estimates and the actual amounts received for product sales in the month that payment is received from the purchaser. Legacy has existing internal controls in place for its estimation process, and any identified differences between its revenue estimates and actual revenue received historically have not been significant. For the twelve months ended December 31, 2018 , revenue recognized in the reporting period related to performance obligations satisfied in prior reporting periods was not material.

Revenues from Contracts with Cu

Revenues from Contracts with Customers	12 Months Ended
Revenues from Contracts with Customers	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	mpact of ASC 606 Adoption On January 1, 2018, Legacy adopted ASU No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”) using the modified retrospective method of transition applied to all contracts. ASU 2014-09 created ASC 606 - Revenue from Contracts with Customers ("ASC 606"), which supersedes nearly all existing revenue recognition guidance under U.S. GAAP and includes a five step process to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. The impact of adoption on Legacy's current period results is as follows (in thousands): Twelve months ended December 31, 2018 Under ASC 606 Under ASC 605 Change (In thousands) Revenues: Oil Sales $ 375,444 $ 375,244 $ (200 ) Natural gas liquids (NGL) sales 27,750 27,232 (518 ) Natural gas sales 151,667 145,135 (6,532 ) $ 554,861 $ 547,611 $ (7,250 ) Costs and expenses: Oil and natural gas production 200,285 193,035 (7,250 ) Net income 43,833 43,833 $ — Partners' deficit, as of January 1, 2018 271,687 271,687 $ — The change to oil sales and a related change to oil production expense are due to the conclusion that Legacy transfers control of oil production to purchasers at or near the wellhead. As such, certain transportation expenses that are deducted from the sales price Legacy receives from the purchaser are presented net in revenue in accordance with ASC 606. This represents a change from Legacy's prior practice under ASC 605 of presenting those transportation costs gross as an oil and natural gas production expense. The change to natural gas and NGL sales and the related change to natural gas production expense are due to the conclusion that Legacy represents an agent in certain gas processing agreements with midstream entities in accordance with the control model in ASC 606. This represents a change from Legacy's previous conclusion utilizing the principal versus agent indicators under ASC 605 that Legacy acted as the principal in those arrangements. As a result, Legacy is required to present certain gathering and processing expenses net in natural gas and NGL sales under ASC 606. Revenue from Contracts with Customers Oil, NGL and natural gas sales revenues are generally recognized at the point in time that control of the product is transferred to the customer and collectability is reasonably assured. This generally occurs when oil or natural gas has been delivered to a pipeline or a tank lifting has occurred. A more detailed summary of the sale of each product type is included below. Oil Sales Legacy's oil sales contracts are generally structured such that Legacy sells its oil production to the purchaser at a contractually specified delivery point at or near the wellhead. The crude oil production is priced on the delivery date based upon prevailing index prices less certain deductions related to oil quality and physical location. Legacy recognizes revenue when control transfers to the purchaser upon delivery at the net price received from purchaser. NGL and Natural Gas Sales Under Legacy's gas processing contracts, Legacy delivers wet gas to a midstream processing entity at the wellhead or the inlet of the midstream processing entity’s system. The midstream processing entity processes the natural gas and remits proceeds to Legacy for the resulting sales of NGLs and residue gas. In these scenarios, Legacy evaluates whether it is the principal or the agent in the transaction. In virtually all of Legacy's gas processing contracts, Legacy has concluded that it is the agent, and the midstream processing entity is Legacy's customer. Accordingly, Legacy recognizes revenue upon delivery based on the net amount of the proceeds received from the midstream processing entity. Proceeds are generally tied to the prevailing index prices for residue gas and NGLs less deductions for gathering, processing, transportation and other expenses. Under Legacy's dry gas sales that do not require processing, Legacy sells its natural gas production to third party purchasers at a contractually specified delivery point at or near the wellhead. Pricing provisions are tied to a market index, with certain deductions based on, among other factors, whether a well delivers to a gathering or transmission line, quality of natural gas, and prevailing supply and demand conditions, so that the price of the natural gas fluctuates to remain competitive with other available natural gas supplies. Legacy recognizes revenue upon delivery of the natural gas to third party purchasers based on the relevant index price net of deductions. Imbalances Natural gas imbalances occur when Legacy sells more or less than its entitled ownership percentage of total natural gas production. Any amount received in excess of its share is treated as a liability. If Legacy receives less than its entitled share, the underproduction is recorded as a receivable. Legacy did not have any significant natural gas imbalance positions as of December 31, 2018, 2017 and 2016. Disaggregation of Revenue Legacy has identified three material revenue streams in its business: oil sales, NGL sales, and natural gas sales. Revenue attributable to each of Legacy's identified revenue streams is disaggregated in the table below. Twelve Months Ended December 31, 2018 (In thousands) Revenues: Oil sales $ 375,444 Natural gas liquids (NGL) sales 27,750 Natural gas sales 151,667 Total revenues $ 554,861 Significant Judgments Principal versus agent Legacy engages in various types of transactions in which midstream entities process its gas and subsequently market resulting NGLs and residue gas to third-party customers on Legacy's behalf, such as Legacy's percentage-of-proceeds and gas purchase contracts. These types of transactions require judgment to determine whether Legacy is the principal or the agent in the contract and, as a result, whether revenues are recorded gross or net. Transaction price allocated to remaining performance obligations A significant number of Legacy's product sales are short-term in nature with a contract term of one year or less. For those contracts, Legacy has utilized the practical expedient in ASC 606 that exempts it from disclosure of the transaction price allocated to remaining performance obligations if the performance obligation is part of a contract that has an original expected duration of one year or less. For Legacy's product sales that have a contract term greater than one year, Legacy has utilized the practical expedient in ASC 606 that states that it is not required to disclose the transaction price allocated to remaining performance obligations if the variable consideration is allocated entirely to a wholly unsatisfied performance obligation. Under these sales contracts, each unit of product represents a separate performance obligation; therefore future volumes are wholly unsatisfied and disclosure of the transaction price allocated to remaining performance obligations is not required. Contract balances Under Legacy's product sales contracts, it is entitled to payment from purchasers once its performance obligations have been satisfied upon delivery of the product, at which point payment is unconditional and invoiced amounts are recorded as “Accounts receivable - oil and natural gas” in its consolidated balance sheet. To the extent actual volumes and prices of oil and natural gas are unavailable for a given reporting period because of timing or information not received from third parties, the expected sales volumes and prices for those properties are estimated and also recorded as “Accounts receivable - oil and natural gas” in the accompanying consolidated balance sheets. In this scenario, payment is also unconditional, as Legacy has satisfied its performance obligations through delivery of the relevant product. As a result, Legacy has concluded that its product sales do not give rise to contract assets or liabilities under ASC 606. Prior-period performance obligations Legacy records revenue in the month production is delivered to the purchaser. However, settlement statements for certain oil, natural gas and NGL sales may not be received for 30 to 60 days after the date production is delivered, and as a result, Legacy is required to estimate the amount of production that was delivered to the midstream purchaser and the price that will be received for the sale of the product. Additionally, to the extent actual volumes and prices of oil are unavailable for a given reporting period because of timing or information not received from third party purchasers, the expected sales volumes and prices for those barrels of oil are also estimated. Legacy records the differences between its estimates and the actual amounts received for product sales in the month that payment is received from the purchaser. Legacy has existing internal controls in place for its estimation process, and any identified differences between its revenue estimates and actual revenue received historically have not been significant. For the twelve months ended December 31, 2018 , revenue recognized in the reporting period related to performance obligations satisfied in prior reporting periods was not material.

Asset Acquisitions and Disposit

Asset Acquisitions and Dispositions	12 Months Ended
Asset Acquisitions and Dispositions	Dec. 31, 2018
Business Combinations [Abstract]
Asset Acquisitions and Dispositions	Asset Acquisitions and Dispositions On August 1, 2017, Legacy made a payment in the amount of $141 million (the “Acceleration Payment”) in connection with its First Amended and Restated Development Agreement (the “Restated Agreement”) with Jupiter JV, LP (“Jupiter”). The Acceleration Payment caused the reversion to Legacy of additional working interests in all wells and associated personal property and infrastructure (collectively, the “Wells”) and all undeveloped assets subject to the Restated Agreement. The transaction was accounted for as an asset acquisition in accordance with ASU 2017-01. Therefore, the acquired interests were recorded based upon the cash consideration paid, with all value assigned to proved oil and natural gas properties. During the year ended December 31, 2018 , Legacy divested certain individually immaterial oil and natural gas assets for net cash proceeds of $55.0 million . These dispositions were treated as asset sales and resulted in a gain on disposition of assets of $23.8 million during the period.

Related Party Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Blue Quail Energy Services, LLC (“Blue Quail”), a company specializing in water transfer services, is an affiliate of Moriah Energy Services LLC, an entity which former Legacy director Cary D. Brown is a principal. Legacy has contracted with Blue Quail to provide water transfer services and paid $169,949 , $9,758 and $98,297 in 2018 , 2017 and 2016 , respectively to Blue Quail for such services.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies From time to time Legacy is a party to various legal proceedings arising in the ordinary course of business. While the outcome of lawsuits cannot be predicted with certainty, Legacy is not currently a party to any proceeding that it believes could have a potential material adverse effect on its financial condition, results of operations or cash flows. Legacy is subject to numerous laws and regulations governing the discharge of materials into the environment or otherwise relating to environmental protection. To the extent laws are enacted or other governmental action is taken that restricts drilling or imposes environmental protection requirements that result in increased costs to the oil and natural gas industry in general, the business and prospects of Legacy could be adversely affected. Legacy has employment agreements with its officers. The employment agreements with its officers specify that if the officer is terminated by Legacy for other than cause or following a change in control, the officer shall receive severance pay ranging from 12 to 36 months salary plus bonus and COBRA benefits, respectively.

Business and Credit Concentrati

Business and Credit Concentrations	12 Months Ended
Business and Credit Concentrations	Dec. 31, 2018
Risks and Uncertainties [Abstract]
Business and Credit Concentrations	Business and Credit Concentrations Cash Legacy maintains its cash in bank deposit accounts, which, at times, may exceed federally insured amounts. Legacy has not experienced any losses in such accounts. Legacy believes it is not exposed to any significant credit risk on its cash. Revenue and Accounts Receivable Substantially all of Legacy’s accounts receivable result from oil and natural gas sales or joint interest billings to third parties in the oil and natural gas industry. This concentration of customers and joint interest owners may impact Legacy’s overall credit risk in that these entities may be similarly affected by changes in economic and other conditions. Historically, Legacy has not experienced significant credit losses on such receivables. No bad debt expense was recorded in 2018 , 2017 or 2016 . Legacy cannot ensure that such losses will not be realized in the future. A listing of oil and natural gas purchasers exceeding 10% of Legacy’s sales is presented in Note 12. Commodity Derivatives Due to the volatility of oil and natural gas prices, Legacy periodically enters into price-risk management transactions (e.g., swaps, collars and enhanced swaps) for a portion of its oil and natural gas production to achieve a more predictable cash flow, as well as to reduce exposure from price fluctuations. Legacy values these transactions at fair value on a recurring basis (Note 10). As of December 31, 2018 , Legacy’s commodity derivative transactions have a fair value favorable to the Company of $67.2 million , collectively. Legacy enters into commodity derivative transactions with entities which Legacy's management believes are creditworthy. In addition, Legacy reviews and assesses the creditworthiness of these institutions on a routine basis. Sales to Major Customers For the year ended December 31, 2018 and 2017 , Legacy sold oil, NGL and natural gas production representing 10% or more of total revenues to the purchasers as detailed in the table below. For the year ended December 31, 2016 , Legacy did not sell oil, NGL or natural gas production representing 10% or more of total revenue to any one customer. 2018 2017 2016 Plains Marketing, LP 20% 10% 6% Rio Energy International Inc 13% 9% 3%

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Values of Financial Instruments The estimated fair values of Legacy’s financial instruments approximate the carrying amounts except as discussed below: Debt. The carrying amount of the revolving long-term debt approximates fair value because Legacy’s current borrowing rate does not materially differ from market rates for similar bank borrowings. The carrying amount of the second lien term loan debt under Legacy’s term loan credit agreement approximates fair value because Legacy’s current borrowing rate does not materially differ from market rates for similar borrowings. The fair value of the 8% senior notes due 2020 (the "2020 Senior Notes"), the 6.625% senior notes due 2021 (the "2021 Senior Notes") and the 8% convertible senior notes due 2023 (the "2023 Convertible Notes") was $97.8 million , $57.9 million and $42.3 million , respectively, as of December 31, 2018 . As these valuations are based on unadjusted quoted prices in an active market, the fair values would be classified as Level 1. Derivatives. See Note 10 for discussion of process used in estimating the fair value of commodity price and interest rate derivatives. Fair Value Measurements Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are classified and disclosed in one of the following categories: Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Legacy considers active markets as those in which transactions for the assets or liabilities occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. This category includes those derivative instruments that Legacy values using observable market data. Substantially all of these inputs are observable in the marketplace throughout the term of the derivative instrument, can be derived from observable data, or are supported by observable levels at which transactions are executed in the marketplace. Instruments in this category include non-exchange traded derivatives such as over-the-counter commodity price swaps and collars and interest rate swaps as well as long-term incentive plan liabilities calculated using the Black-Scholes model to estimate the fair value as of the measurement date. Level 3: Measured based on prices or valuation models that require inputs that are both significant to the fair value measurement and less observable from objective sources (i.e. supported by little or no market activity). Legacy’s valuation models are primarily industry standard models that consider various inputs including: (a) quoted forward prices for commodities, (b) time value, and (c) current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Level 3 instruments currently are limited to Midland-Cushing crude oil differential swaps. Although Legacy utilizes third party broker quotes to assess the reasonableness of its prices and valuation techniques, Legacy does not have sufficient corroborating evidence to support classifying these assets and liabilities as Level 2. Financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. Legacy’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. Fair Value on a Recurring Basis The following table sets forth by level within the fair value hierarchy Legacy’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2018 and 2017 : December 31, 2018 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Total Fair Value Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Description (Level 1) (Level 2) (Level 3) (In thousands) Assets: Current Commodity derivatives $ — $ 69,288 $ — $ 69,288 $ (4,670 ) $ 64,618 Interest rate derivatives — 2,044 — 2,044 — 2,044 Noncurrent Commodity derivatives — 3,473 — 3,473 (338 ) 3,135 Interest rate derivatives — — — — — — Liabilities: Current Commodity derivatives — (4,670 ) — (4,670 ) 4,670 — Noncurrent Commodity derivatives — (888 ) — (888 ) 338 (550 ) $ — $ 69,247 $ — $ 69,247 $ — $ 69,247 December 31, 2017 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Total Fair Value Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Description (Level 1) (Level 2) (Level 3) (In thousands) Assets: Current Commodity derivatives $ — $ 19,792 $ — $ 19,792 $ (7,204 ) $ 12,588 Interest rate derivatives — 837 — 837 (1 ) 836 Noncurrent Commodity derivatives — 14,278 — 14,278 (1,460 ) 12,818 Interest rate derivatives — 1,281 — 1,281 1,281 Liabilities: Current Commodity derivatives — (21,027 ) (4,191 ) (25,218 ) 7,204 (18,014 ) Interest rate derivatives — (1 ) — (1 ) 1 — LTIP liability — (1,947 ) — (1,947 ) (1,947 ) Noncurrent Commodity derivatives — (1,637 ) (897 ) (2,534 ) 1,460 (1,074 ) Interest rate derivatives — — — $ — $ 11,576 $ (5,088 ) $ 6,488 $ — $ 6,488 Legacy estimates the fair values of its commodity swaps based on published forward commodity price curves for the underlying commodities as of the date of the estimate for those commodities for which published forward pricing is readily available. For those commodity derivatives for which forward commodity price curves are not readily available, Legacy estimates, with the assistance of third-party pricing experts, the forward curves as of the date of the estimate. Legacy validates the data provided by third parties by understanding the pricing models used, obtaining market values from other pricing sources, analyzing pricing data in certain situations and confirming, where applicable, that those securities trade in active markets. Legacy estimates the option value of puts and calls combined into hedges, including costless collars, three-way collars and enhanced swaps using an option pricing model which takes into account market volatility, market prices, contract parameters and discount rates based on published LIBOR rates and interest swap rates. Due to the lack of an active market for periods beyond one-month from the balance sheet date for Legacy's oil price differential swaps, Legacy has reviewed historical differential prices and known economic influences to estimate a reasonable forward curve of future pricing scenarios based upon these factors. In order to estimate the fair value of its interest rate swaps, Legacy uses a yield curve based on money market rates and interest rate swaps, extrapolates a forecast of future interest rates, estimates each future cash flow, derives discount factors to value the fixed and floating rate cash flows of each swap, and then discounts to present value all known (fixed) and forecasted (floating) swap cash flows. Curve building and discounting techniques used to establish the theoretical market value of interest bearing securities are based on readily available money market rates and interest swap market data. The determination of the fair values above incorporates various factors including the impact of Legacy's non-performance risk and the credit standing of the counterparties involved in Legacy’s derivative contracts. The risk of nonperformance by Legacy’s counterparties is mitigated by the fact that enters into derivative transactions with entities which Legacy's management believes are creditworthy. In addition, Legacy routinely monitors the creditworthiness of its counterparties. As the factors described above are based on significant assumptions made by management, these assumptions are the most sensitive to change. The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy: Significant Unobservable Inputs (Level 3) December 31, 2018 2017 2016 (In thousands) Beginning balance $ (5,088 ) $ 8 $ (4,493 ) Total gains (losses) 30,571 (5,073 ) 253 Settlements (22,379 ) (23 ) 4,248 Transfers (3,104 ) (a) — — Ending balance $ — $ (5,088 ) $ 8 Gains (losses) included in earnings relating to derivatives still held as of December 31, 2018, 2017 and 2016 $ — $ (5,088 ) $ 68 ____________________ (a) Due to the lack of a historical market, we have historically accounted for our Midland-to-Cushing crude oil differential swaps as Level 3. However, with recent widening differentials, an active market has been created in which quoted prices are readily observable. As such, we have determined that the inputs used to value these derivatives now classify as Level 2 and transferred the value of the derivatives into Level 2. During periods of market disruption, including periods of volatile oil and natural gas prices, rapid credit contraction or illiquidity, it may be difficult to value certain of the Legacy's derivative instruments if trading becomes less frequent and/or market data becomes less observable. There may be certain asset classes that were in active markets with observable data that become illiquid due to changes in the financial environment. In such cases, more derivative instruments may fall to Level 3 and thus require more subjectivity and management judgment. As such, valuations may include inputs and assumptions that are less observable or require greater estimation as well as valuation methods which are more sophisticated or require greater estimation thereby resulting in valuations with less certainty. Further, rapidly changing commodity and unprecedented credit and equity market conditions could materially impact the valuation of derivative instruments as reported within Legacy's consolidated financial statements and the period-to-period changes in value could vary significantly. Decreases in value may have a material adverse effect on Legacy's results of operations or financial condition. Fair Value on a Non-Recurring Basis Nonfinancial assets and liabilities measured at fair value on a non-recurring basis include certain nonfinancial assets and liabilities as may be acquired in a business combination, measurements of oil and natural gas property impairments, and the initial recognition of asset retirement obligations, for which fair value is used. These asset retirement obligation ("ARO") estimates are derived from historical costs as well as management’s expectation of future cost environments. As there is no corroborating market activity to support the assumptions used, Legacy has designated these measurements as Level 3. A reconciliation of the beginning and ending balances of Legacy’s ARO is presented in Note 13. Nonrecurring fair value measurements of proved oil and natural gas properties during the years ended December 31, 2018 and 2017 consist of adjustments of the carrying value oil and natural gas properties to their fair value of $43.9 million and $31.9 million , respectively. Legacy periodically reviews oil and natural gas properties for impairment when facts and circumstances indicate that their carrying value may not be recoverable. During the year ended December 31, 2018 , Legacy incurred impairment charges of $58.7 million as oil and natural gas properties with a net cost basis of $102.6 million were written down to their fair value of $43.9 million . During the year ended December 31, 2017 , Legacy incurred impairment charges of $37.3 million as oil and natural gas properties with a net cost basis of $69.1 million were written down to their fair value of $31.8 million . In order to determine whether the carrying value of an asset is recoverable, Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. If the net capitalized cost exceeds the undiscounted future net cash flows, Legacy writes the net cost basis down to the discounted future net cash flows, which is management's estimate of fair value. Significant inputs used to determine the fair value include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices; and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in the Company's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. The inputs used by management for the fair value measurements utilized in this review include significant unobservable inputs, and therefore, the fair value measurements employed are classified as Level 3 for these types of assets. The remaining $9.3 million of impairment during the year ended December 31, 2018 represented impairment of unproved properties acquired since 2010 that are no longer viable for development.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
Derivative Financial Instruments	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments Commodity derivative transactions Due to the volatility of oil and natural gas prices, Legacy periodically enters into price-risk management transactions (e.g., swaps and enhanced swaps) for a portion of its oil and natural gas production to achieve a more predictable cash flow, as well as to reduce exposure from price fluctuations. While the use of these arrangements limits Legacy’s ability to benefit from increases in the prices of oil and natural gas, it also reduces Legacy’s potential exposure to adverse price movements. Legacy’s arrangements, to the extent it enters into any, apply to only a portion of its production, provide only partial price protection against declines in oil and natural gas prices and limit Legacy’s potential gains from future increases in prices. None of these instruments are used for trading or speculative purposes. These derivative instruments are intended to mitigate a portion of Legacy’s price-risk and may be considered hedges for economic purposes, but Legacy has chosen not to designate them as cash flow hedges for accounting purposes. Therefore, all derivative instruments are recorded on the balance sheet at fair value with changes in fair value being recorded in current period earnings. By using derivative instruments to mitigate exposures to changes in commodity prices, Legacy exposes itself to credit risk and market risk. Credit risk is the failure of the counterparty to perform under the terms of the derivative contract. When the fair value of a derivative contract is positive, the counterparty owes Legacy, which creates credit risk. Legacy minimizes the credit or repayment risk in derivative instruments by entering into transactions with high-quality counterparties. The following table sets forth a reconciliation of the changes in fair value of Legacy's commodity derivatives for the years ended December 31, 2018 , 2017 , and 2016 . December 31, 2018 2017 2016 (In thousands) Beginning fair value of commodity derivatives $ 6,318 $ 12,698 $ 118,427 Total gain (loss) crude oil derivatives 54,380 (15,325 ) (9,410 ) Total gain (loss) natural gas derivatives (5,208 ) 33,101 (31,814 ) Crude oil derivative cash settlements paid (received) 16,845 (11,840 ) (37,464 ) Natural gas derivative cash settlements received (5,130 ) (12,316 ) (27,041 ) Ending fair value of commodity derivatives $ 67,205 $ 6,318 $ 12,698 As of December 31, 2018 , Legacy had the following NYMEX WTI crude oil swaps paying floating prices and receiving fixed prices for a portion of its future oil production as indicated below: Calendar Year Volumes (Bbls) Average Price per Bbl Price Range per Bbl 2019 3,285,000 $61.33 $57.15 - $67.65 As of December 31, 2018 , Legacy had the following Midland-to-Cushing crude oil differential swaps paying a floating differential and receiving a fixed differential for a portion of its future oil production as indicated below: Calendar Year Volumes (Bbls) Average Price per Bbl Price Range per Bbl 2019 2,193,000 $(3.62) $(5.60) - $(1.15) As of December 31, 2018 , Legacy had the following Midland-to-Cushing crude oil differential enhanced swaps paying a floating differential and receiving a fixed differential for a portion of its future oil production as indicated below: Calendar Year Volumes (Bbls) Average Short Call Price per Bbl Average Swap Price per Bbl 2019 $1,460,000 $70.00 $(2.91) As of December 31, 2018 , Legacy had the following NYMEX Henry Hub natural gas swaps paying floating natural gas prices and receiving fixed prices for a portion of its future natural gas production as indicated below: Average Price Range Calendar Year Volumes (MMBtu) Price per MMBtu per MMBtu 2019 37,175,000 $3.36 $3.05 - $4.40 As of December 31, 2018 , Legacy had the following Henry Hub NYMEX to CIG natural gas differential swaps paying a floating differential and receiving a fixed differential for a portion of its future natural gas production as indicated below: Average Price Range Calendar Year Volumes (MMBtu) Price per MMBtu per MMBtu 2019 3,600,000 $(0.47) $(0.46) - $(0.49) Interest rate derivative transactions Due to the volatility of interest rates, Legacy periodically enters into interest rate risk management transactions in the form of interest rate swaps for a portion of its outstanding debt balance. These transactions allow Legacy to reduce exposure to interest rate fluctuations. While the use of these arrangements limits Legacy’s ability to benefit from decreases in interest rates, it also reduces Legacy’s potential exposure to increases in interest rates. Legacy’s arrangements, to the extent it enters into any, apply to only a portion of its outstanding debt balance, provide only partial protection against interest rate increases and limit Legacy’s potential savings from future interest rate declines. It is never management’s intention to hold or issue derivative instruments for speculative trading purposes. Conditions sometimes arise where actual borrowings are less than notional amounts hedged which has and could result in overhedged amounts. Legacy does not designate these derivatives as cash flow hedges, even though they reduce its exposure to changes in interest rates. Therefore, the mark-to-market of these instruments is recorded in current earnings and classified as a component of interest expense. The total impact on interest expense from the mark-to-market and settlements was as follows: December 31, 2018 2017 2016 (In thousands) Beginning fair value of interest rate swaps $ 2,117 $ 183 $ (362 ) Total gain (loss) loss on interest rate swaps 1,213 1,168 (2,108 ) Cash settlements paid (1,286 ) 766 2,653 Ending fair value of interest rate swaps $ 2,044 $ 2,117 $ 183 The table below summarizes the interest rate swap assets and liabilities as of December 31, 2018 . Weighted Average Fixed Effective Maturity Estimated Fair Market Value at December 31, Notional Amount Rate Date Date 2018 (Dollars in thousands) $235,000 1.363 % 9/1/2015 9/1/2019 2,044 Total fair value of interest rate derivatives $ 2,044

Sales to Major Customers

Sales to Major Customers	12 Months Ended
Sales to Major Customers	Dec. 31, 2018
Risks and Uncertainties [Abstract]
Sales to Major Customers	Business and Credit Concentrations Cash Legacy maintains its cash in bank deposit accounts, which, at times, may exceed federally insured amounts. Legacy has not experienced any losses in such accounts. Legacy believes it is not exposed to any significant credit risk on its cash. Revenue and Accounts Receivable Substantially all of Legacy’s accounts receivable result from oil and natural gas sales or joint interest billings to third parties in the oil and natural gas industry. This concentration of customers and joint interest owners may impact Legacy’s overall credit risk in that these entities may be similarly affected by changes in economic and other conditions. Historically, Legacy has not experienced significant credit losses on such receivables. No bad debt expense was recorded in 2018 , 2017 or 2016 . Legacy cannot ensure that such losses will not be realized in the future. A listing of oil and natural gas purchasers exceeding 10% of Legacy’s sales is presented in Note 12. Commodity Derivatives Due to the volatility of oil and natural gas prices, Legacy periodically enters into price-risk management transactions (e.g., swaps, collars and enhanced swaps) for a portion of its oil and natural gas production to achieve a more predictable cash flow, as well as to reduce exposure from price fluctuations. Legacy values these transactions at fair value on a recurring basis (Note 10). As of December 31, 2018 , Legacy’s commodity derivative transactions have a fair value favorable to the Company of $67.2 million , collectively. Legacy enters into commodity derivative transactions with entities which Legacy's management believes are creditworthy. In addition, Legacy reviews and assesses the creditworthiness of these institutions on a routine basis. Sales to Major Customers For the year ended December 31, 2018 and 2017 , Legacy sold oil, NGL and natural gas production representing 10% or more of total revenues to the purchasers as detailed in the table below. For the year ended December 31, 2016 , Legacy did not sell oil, NGL or natural gas production representing 10% or more of total revenue to any one customer. 2018 2017 2016 Plains Marketing, LP 20% 10% 6% Rio Energy International Inc 13% 9% 3%

Asset Retirement Obligation

Asset Retirement Obligation	12 Months Ended
Asset Retirement Obligation	Dec. 31, 2018
Asset Retirement Obligation [Abstract]
Asset Retirement Obligation	Asset Retirement Obligation An asset retirement obligation (“ARO”) associated with the retirement of a tangible long-lived asset is recognized as a liability in the period in which it is incurred and becomes determinable. When liabilities for dismantlement and abandonment costs, excluding salvage values, are initially recorded, the carrying amount of the related oil and natural gas properties is increased. The fair value of the additions to the ARO asset and liability is estimated using valuation techniques that convert future cash flows to a single discounted amount. Significant inputs to the valuation include estimates of: (i) plug and abandon costs per well based on existing regulatory requirements; (ii) remaining life per well; (iii) future inflation factors; and (iv) a credit-adjusted risk-free interest rate. These inputs require significant judgments and estimates by Legacy's management at the time of the valuation and are the most sensitive and subject to change. Accretion of the liability is recognized each period using the interest method of allocation, and the capitalized cost is depleted using the units of production method. Should either the estimated life or the estimated abandonment costs of a property change materially upon Legacy’s periodic review, a new calculation is performed using the same methodology of taking the abandonment cost and inflating it forward to its abandonment date and then discounting it back to the present using Legacy’s credit-adjusted-risk-free rate. The carrying value of the ARO is adjusted to the newly calculated value, with a corresponding offsetting adjustment to the asset retirement cost. When obligations are relieved by sale of the property or plugging and abandoning the well, the related liability and asset costs are removed from Legacy's balance sheet. Any difference in the cost to plug and the related liability is recorded as a gain or loss on Legacy's statement of operations in the disposal of assets line item. The following table reflects the changes in the ARO during the years ended December 31, 2018 , 2017 and 2016 . December 31, 2018 2017 2016 (In thousands) Asset retirement obligation — beginning of period $ 274,686 $ 272,148 $ 286,405 Liabilities incurred with properties acquired 226 62 24 Liabilities incurred with properties drilled 65 39 1 Liabilities settled during the period (2,258 ) (1,891 ) (2,351 ) Liabilities associated with properties sold (27,673 ) (8,464 ) (24,605 ) Current period accretion 12,568 12,792 12,674 Current period revisions to previous estimates (4,880 ) — — Asset retirement obligation — end of period $ 252,734 $ 274,686 $ 272,148 Each year Legacy reviews and, to the extent necessary, revises its ARO estimates. During 2018 , Legacy reviewed future anticipated abandonment dates with previous estimates and, as a result, decreased its estimate of future asset retirement obligations by $4.9 million . During 2016 and 2017 , no revisions of previous estimates were deemed necessary.

Stockholders' Deficit_Partners'

Stockholders' Deficit/Partners' Deficit	12 Months Ended
Stockholders' Deficit/Partners' Deficit	Dec. 31, 2018
Equity [Abstract]
Stockholders' Deficit/Partners' Deficit	Stockholders' Deficit / Partners' Deficit Preferred Units On September 20, 2018, in connection with the Corporate Reorganization, all of Legacy LP's 8% Series A Fixed-to-Floating Cumulative Redeemable Perpetual Preferred Units and 8.000% Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units outstanding were converted into shares of common stock. Incentive Distribution Units On September 20, 2018, all of Legacy LP's Incentive Distribution Units outstanding were cancelled in connection with the Corporate Reorganization. Loss per share / unit The following table sets forth the computation of basic and diluted loss per share / unit: Years Ended December 31, 2018 2017 2016 (In thousands) Income/(loss) $ 43,833 $ (53,897 ) $ (55,820 ) Income/(loss) attributable to shareholders $ 43,833 $ (53,897 ) $ (55,820 ) Weighted average number of shares outstanding 105,087 100,049 98,249 Effect of dilutive securities: Restricted and phantom units — — — Weighted average units and potential units outstanding 105,087 100,049 98,249 Basic and diluted income/(loss) per share $ 0.42 $ (0.54 ) $ (0.57 ) As of December 31, 2018 , 7,302,809 restricted stock units were excluded from the calculation of diluted earnings per share due to their anti-dilutive effect. As of December 31, 2017 , 241,373 restricted units and 1,389,773 phantom units were excluded from the calculation of diluted earnings per unit due to their anti-dilutive effect. As of December 31, 2016 , 484,447 restricted units and 1,212,692 phantom units were excluded from the calculation of diluted earnings per unit due to their anti-dilutive effect. As of December 31, 2018 , 21,356,510 shares related to 2023 Convertible Notes were excluded from the calculation of diluted earnings per share due to their anti-dilutive effect.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
Stock-Based Compensation	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Legacy LP Long Term Incentive Plan On March 15, 2006, a Long-Term Incentive Plan (as amended, “LTIP”) for Legacy was created and Legacy adopted the LTIP for its employees, consultants and directors, its affiliates and its general partner. The awards under the long-term incentive plan may include unit grants, restricted units, phantom units, unit options and unit appreciation rights (“UARs”). The LTIP permits the grant of awards that may be made or settled in units up to an aggregate of 5,000,000 units. As of September, 2018 grants of awards net of forfeitures and, in the case of phantom units, historical exercises covering 3,459,197 units had been made, comprised of 266,014 unit option awards, 988,207 restricted unit awards, 1,424,114 phantom unit awards and 780,862 unit awards. Pursuant to the terms of the Corporate Reorganization, the Legacy LP long-term incentive plan ("Legacy LP LTIP") was terminated. Unit Appreciation Rights A UAR is a notional unit that entitles the holder, upon vesting, to receive cash valued at the difference between the closing price of units on the exercise date and the exercise price, as determined on the date of grant. Because these awards are settled in cash, Legacy accounts for the UARs under the liability method. During the year ended December 31, 2016 , Legacy issued (i) 204,500 UARs to employees which vest ratably over a three -year period and (ii) 96,520 UARs to employees which cliff-vest at the end of a three -year period. Legacy did not issue UARs to employees during the years ended December 31, 2017 and 2018 . All outstanding UARs were exercised or forfeited in connection with the Corporate Reorganization. For the years ended December 31, 2018 , 2017 and 2016 , Legacy recorded compensation (benefit) expense of $(169,024) , $(37,240) and $223,569 , respectively, due to the changes in the compensation liability related to the above awards based on its use of the Black-Scholes model to estimate the December 31, 2018 , 2017 and 2016 fair value of these UARs. All outstanding UARs vested on September 20, 2018 in connection with the Corporate Reorganization and were subsequently exercised or forfeited. The cost of employee services in exchange for an award of equity instruments was measured based on a grant-date fair value of the award (with limited exceptions), and that cost was generally recognized over the vesting period of the award. However, if an entity that nominally has the choice of settling awards by issuing stock predominately settles in cash, or if an entity usually settles in cash whenever an employee asks for cash settlement, the entity is settling a substantive liability rather than repurchasing an equity instrument. Because the UARs were settled in cash, Legacy accounted for them by utilizing the liability method. The liability method requires companies to measure the cost of the employee services in exchange for a cash award based on the fair value of the underlying security at the end of each reporting period. Compensation cost was recognized based on the change in the liability between periods. A summary of UAR activity for the year ended December 31, 2018 , 2017 and 2016 is as follows: Units Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2016 936,116 $ 20.61 Expired (21,067 ) $ 16.07 Forfeited (30,503 ) $ 19.80 Outstanding at December 31, 2016 884,546 $ 20.75 3.67 $ — UARs exercisable at December 31, 2016 570,369 $ 24.38 2.77 $ — Outstanding at January 1, 2017 884,546 $ 20.75 Expired (147,024 ) $ 24.50 Forfeited (15,501 ) $ 13.91 Outstanding at December 31, 2017 722,021 $ 20.13 3.29 $ — UARs exercisable at December 31, 2017 592,522 $ 23.23 2.99 $ — Outstanding at January 1, 2018 722,021 $ 20.13 Expired (90,844 ) $ 4.69 Forfeited (631,177 ) $ 22.35 Outstanding at December 31, 2018 — $ — 0.00 $ — UARs exercisable at December 31, 2018 — $ — 0.00 $ — The following table summarizes the status of Legacy’s non-vested UARs since January 1, 2018 : Non-Vested UARs Number of Units Weighted- Average Exercise Price Non-vested at January 1, 2018 129,499 $ 5.97 Vested (124,832 ) 5.99 Forfeited (4,667 ) 5.25 Non-vested at December 31, 2018 — $ — Phantom Units Legacy previously issued phantom units under the Legacy LP LTIP to executive officers. A phantom unit is a notional unit that entitles the holder, upon vesting, to receive either one Partnership unit for each phantom unit or the cash equivalent of a Partnership unit, as stipulated by the form of the grant. Legacy accounted for the phantom units settled in Partnership units by utilizing the equity method. Legacy accounted for the phantom units settled in cash by utilizing the liability method. 391,674 Phantom units that settle in cash and 1,032,440 phantom units that settle in units vested on September 20, 2018 in connection with the Corporate Reorganization. Compensation expense related to the phantom units was $22.9 million , $4.6 million and $3.7 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Restricted Units Legacy LP previously issued restricted units to certain employees and members of management. All restricted units vested on September 20, 2018 in connection with the Corporate Reorganization. Compensation expense related to restricted units was $0.8 million , $1.5 million and $2.7 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Board Units On May 10, 2016 , Legacy granted and issued 39,526 units to each of its five non-employee directors as part of their annual compensation for serving on the board of directors of Legacy’s general partner. The value of each unit was $2.59 at the time of issuance. On May 16, 2017 , Legacy granted and issued 47,847 units to each of its six non-employee directors as part of their annual compensation for serving on the board of directors of Legacy’s general partner. The value of each unit was $2.04 at the time of issuance. On May 15, 2018 , Legacy granted and issued 12,019 units to four non-employee directors who serve on the Board of Directors of Legacy and 6,010 units to two non-employee directors of Legacy LP who do not serve on the Board of Directors of Legacy Inc. The value of each unit was $8.69 at the time of issuance. None of these units were subject to vesting. Legacy recognized the expense associated with the unit grants on the date of grant. Legacy Reserves Inc. 2018 Omnibus Incentive Plan On September 19, 2018, the Legacy Inc. 2018 Omnibus Incentive Plan (the "Legacy Inc. LTIP") was approved by the former unitholders of Legacy LP in connection with the Corporate Reorganization for it and its affiliates' employees, consultants and directors. The Legacy Inc. LTIP provides for up to 10,500,000 shares (the "Share Reserve") to be used for awards, and that the Share Reserve will increase proportionately by 10% of all shares of common stock issued by Legacy Inc. after the effective date of the Legacy Inc. LTIP and before the first anniversary of the effective date. The awards under the Legacy Inc. LTIP may include stock grants, restricted stock, restricted stock units and stock options. As of December 31, 2018 , grants of awards net of forfeitures covering 7,335,379 shares had been made, compromised of 7,302,809 restricted stock units and 32,570 stock awards. Restricted Stock Units During the twelve months ended December 31, 2018 , Legacy issued an aggregate 7,302,809 restricted stock units ("RSUs") to both executive and non-executive employees. The RSUs vest generally over a three or four-year period. Compensation expense related to the RSUs was $4.1 million for the twelve months ended December 31, 2018 . RSUs are accounted for under the equity method. A summary of RSU activity for the year ended December 31, 2018 is as follows: Number of Restricted Stock Units Weighted Average Grant Date Fair Value Outstanding at January 1, 2018 — $ — Granted 7,523,720 $ 4.89 Expired — $ — Forfeited (220,911 ) $ 5.14 Outstanding at December 31, 2018 7,302,809 $ 4.88 As of December 31, 2018 , there was a total of $31.5 million of unrecognized compensation expense related to the unvested portion of these RSUs. At December 31, 2018 , this cost was expected to be recognized over a weighted-average period of 3.2 years. Pursuant to the provisions of ASC 718, Legacy's issued shares, as reflected in the accompanying consolidated balance sheet at December 31, 2018 , do not include 7,302,809 shares related to unvested RSUs. Board Shares On September 25, 2018, Legacy granted and issued 5,030 shares to four non-employee directors who serve on the Board of Directors of Legacy in accordance with Legacy's director compensation policy. The value of each share was $4.97 at the time of issuance. On October 16, 2018, Legacy granted and issued 12,450 shares to one non-employee director who serves on the Board of Directors of Legacy in accordance with Legacy's director compensation policy. The value of each share was $5.02 at the time of issuance.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Effective September 20, 2018, pursuant to the Merger Agreement, Legacy Inc. became subject to federal and state income taxes. Prior to consummation of the Corporate Reorganization, Legacy LP was treated as a partnership for federal and state income tax purposes, in which the taxable income or loss was passed through to its unitholders. With the exception of the state of Texas and certain subsidiaries, Legacy LP did not directly pay federal and state income taxes and recognition was not given to federal and state income taxes for its operations. On December 22, 2017, Public Law No. 115-97, commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”) was enacted into law. The provisions of the Tax Act that impact Legacy include, but are not limited to, (1) reducing the U.S. federal corporate income tax rate from 35% to 21% , (2) full expensing of certain qualified property acquired after September 27, 2017, (3) limitations on the maximum deduction for net operating loss (NOL) as well as indefinite life carryforwards for tax years beginning after December 31, 2017 and (4) limitations on the maximum deduction for net business interest expense in tax years beginning after December 31, 2017. Legacy has previously recorded all amounts for the income effects of the Tax Act as of December 31, 2017. The effective income tax rates for the years ended December 31, 2018 , 2017 and 2016 were 6.3% and (2.7)% and (2.3)% , respectively. For the year ended December 31, 2018 , our effective tax rate differed from the statutory rate primarily due to Legacy LP’s income not being subject to U.S. federal income tax, 2023 Convertible Notes issuance, Texas margins tax, and the valuation allowance. For the twelve months ended December 31, 2017 , our effective tax rate differed from the statutory rate primarily due to Legacy LP’s income not being subject to U.S. federal income tax and Texas margins tax. For the year ended December 31, 2016 , our effective tax rate differed from the statutory rate primarily due to Legacy LP’s income not being subject to U.S. federal income tax and Texas margins tax. For the years ended December 31, 2018 , 2017 and 2016 we recorded income/(loss) before income taxes of $46.8 million , $(52.5) million and $(54.6) million , respectively. All of Legacy's income is sourced within the United States. The income tax expense (benefit) consists of: Years Ended December 31, 2018 2017 2016 (In thousands) Current: Federal $ 140 $ 1,911 $ 1,183 State (147 ) (52 ) (193 ) Total current income tax expense (benefit) (7 ) 1,859 990 Deferred: Federal $ 1,270 $ (464 ) $ (782 ) State 1,705 3 1,021 Total deferred income tax expense (benefit) 2,975 (461 ) 239 Total income tax expense $ 2,968 $ 1,398 $ 1,229 A reconciliation of the federal statutory tax rate to the effective tax rate is as follows: Years Ended December 31, 2018 2017 2016 Tax at federal statutory rate 21.0 % 35.0 % 35.0 % Partnership loss not subject to federal tax 16.6 % (36.1 )% (35.7 )% Federal rate change — % (1.6 )% — % 2023 Convertible Notes issuance 7.4 % — % — % Valuation allowance adjustment (44.1 )% — % — % Texas margins tax 6.1 % (1.6 )% (2.0 )% Other (0.7 )% 1.6 % 0.4 % Effective tax rate 6.3 % (2.7 )% (2.3 )% Deferred income tax balances representing the tax effect of temporary differences between the financial statement carrying amounts and the tax basis of assets and liabilities are as follows: December 31, 2018 2017 (In thousands) Deferred tax assets: Oil and natural gas properties $ 91,948 $ 1,840 Net operating losses 12,961 — Interest expense 6,668 — Other — 1,176 Total deferred tax assets 111,577 3,016 Deferred tax liabilities Hedging activities (15,934 ) (32 ) Other (1,585 ) (11 ) Total deferred tax liabilities (17,519 ) (43 ) Valuation allowance (94,058 ) — Net deferred tax assets $ — $ 2,973 At December 31, 2018 , Legacy had a federal net operating loss carry forward of $57 million , which are subject to an 80% taxable income limitation under the Tax Act. Legacy also has a net interest expense carryover of $29 million under Section 163(j) of the Code subject to indefinite carryover. Legacy has state net operating loss carry forwards of approximately $21 million which will expire in varying amounts beginning in 2023. Legacy has recorded a full valuation allowance against the federal net operating losses, the state net operating losses, the net interest expense carryover and other deferred tax assets and liabilities because it is probable that these attributes will not be realized. In assessing the realizability of net deferred tax assets, Legacy's management assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. On the basis of this evaluation, as of December 31, 2018 , a full valuation allowance has been recorded as management has determined that it is more likely than not that the net deferred tax asset will not be realized. The full valuation allowance could be adjusted in future periods if objective negative evidence is no longer present and additional weight is given to subjective evidence. In accordance with the applicable accounting standards, Legacy recognizes only the impact of income tax positions that, based on their merits, are more likely than not to be sustained upon audit by a taxing authority. To evaluate its current tax positions to identify any material uncertain tax positions, Legacy developed a policy of identifying and evaluating uncertain tax positions that considers support for each tax position, industry standards, tax return disclosures and schedules and the significance of each position. It is Legacy’s policy to recognize interest and penalties, if any, related to unrecognized tax benefits in income tax expense. The Company had no material uncertain tax positions at December 31, 2018 . The tax years 2010 through 2018 remain subject to examination by the major tax jurisdictions.

Guarantors

Guarantors	12 Months Ended
Guarantors	Dec. 31, 2018
Guarantees [Abstract]
Guarantors	Guarantors Legacy LP's 2020 Senior Notes were issued in a private offering on December 4, 2012 and were subsequently registered through a public exchange offer that closed on January 8, 2014. Legacy LP's 2021 Senior Notes were issued in two separate private offerings on May 28, 2013 and May 8, 2014. $250 million aggregate principal amount of our 2021 Senior Notes were subsequently registered through a public exchange offer that closed on March 18, 2014. The remaining $300 million of aggregate principal amount of Legacy's 2021 Senior Notes were subsequently registered through a public exchange offer that closed on February 10, 2015. Legacy LP's 2023 Convertible Notes were issued in exchange for portions of the 2020 Senior Notes and 2021 Senior Notes on September 20, 2018. The 2020 Senior Notes, the 2021 Senior Notes and the 2023 Convertible Notes are guaranteed by Legacy LP's 100% owned subsidiaries Legacy Reserves Operating GP LLC, Legacy Reserves Operating LP, Legacy Reserves Services LLC, Legacy Reserves Energy Services LLC, Legacy Marketing LLC, Dew Gathering LLC and Pinnacle Gas Treating LLC, which constitute all of Legacy's wholly-owned subsidiaries other than Legacy Reserves Finance Corporation, and certain other future subsidiaries (the “Guarantors”, together with any future 100% owned subsidiaries that guarantee the Partnership's 2020 Senior Notes, 2021 Senior Notes and the 2023 Convertible Notes, the “Subsidiaries”) as well as Legacy Inc. and the General Partner, as parent guarantors (the "Parent Guarantors"). The Subsidiaries are 100% owned, directly or indirectly, by the Partnership and the guarantees by the Subsidiaries are full and unconditional, except for customary release provisions described in “—Footnote 2—Debt.” Legacy LP is 100% owned, directly or indirectly, by the Parent Guarantors and the guarantees by the Parent Guarantors are full and unconditional, except for customary release provisions described in “—Footnote 3—Debt.” Legacy LP has no assets or operations independent of the Subsidiaries, and there are no significant restrictions upon the ability of the Subsidiaries to distribute funds to the Partnership. The guarantees constitute joint and several obligations of the Guarantors and Parent Guarantors.

Subsequent Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Amendments to Credit Agreement and Term Loan Credit Agreement On March 21, 2019, we entered into the Twelfth Amendment (the “Twelfth Amendment”) to our Credit Agreement. The Twelfth Amendment provides for, among other things, (i) an extension of the maturity of the Credit Agreement to May 31, 2019, (ii) an increase in the applicable interest rate by 2.25% , (iii) the payment of a fee equal to 0.35% of the amount of the current borrowing base under the Credit Agreement, payable on the effective date of the Twelfth Amendment, (iv) the mandatory termination of our derivative contracts three days prior to the maturity of the Credit Agreement, (vi) the reduction in the borrowing base from $575 million to $570 million , effective May 22, 2019, (vii) the reduction in the maximum consolidated cash balance we can maintain without prepaying the loans to $15 million , effective April 1, 2019 and (viii) the payment of a fee equal to 0.15% of the amount of the current borrowing base under the Credit Agreement, payable on the earliest to occur of (x) May 31, 2019 or (y) an acceleration of the outstanding indebtedness under the Credit Agreement. Additionally, the Amendment waives certain deviations from the requirements of the Credit Agreement, including the delivery of fiscal year 2018 audited financial statements with a “going concern” or like qualification or exception and non-compliance with the current ratio covenant for the fourth quarter of 2018. On March 21, 2019, we entered into the Seventh Amendment (the “Seventh Amendment”) to our Term Loan Credit Agreement. The Seventh Amendment waives, through May 31, 2019, the requirement of the Term Loan Credit Agreement that the delivery of fiscal year 2018 audited financial statements not include a “going concern” or like qualification or exception. The Seventh Amendment also provides for, among other things, (i) an increase in the applicable interest rate by 2.25% , (ii) a fee equal to 0.35% of the aggregate amount of term loans currently outstanding under the Term Loan Credit Agreement, to be paid in kind by increasing the aggregate amount of term loans outstanding as of the effective date of the Seventh Amendment and (iii) a fee equal to 0.15% of the aggregate amount of term loans currently outstanding under the Term Loan Credit Agreement, to be paid in kind by increasing the aggregate amount of term loans outstanding on the earliest to occur of (x) May 31, 2019 or (y) an acceleration of the outstanding indebtedness under the Term Loan Credit Agreement.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Basis of Presentation and Description of Business	Organization, Basis of Presentation and Description of Business Unless the context requires otherwise or unless otherwise noted, all references to “Legacy Reserves,” “Legacy Inc.,” “Legacy,” the “Company,” “we,” “us,” “our” or like terms are to Legacy Reserves Inc. and its subsidiaries for the periods after September 20, 2018, the date the Corporate Reorganization was consummated (as defined below). For the periods prior to September 20, 2018, unless the context requires otherwise or unless otherwise noted, all references to “Legacy Reserves,” “Legacy LP,” “Legacy,” the “Company,” “we,” “us,” “our” or like terms are to Legacy Reserves LP and its subsidiaries. Legacy is an independent energy company engaged in the development, production and acquisition of oil and natural gas properties in the United States. Its current operations are focused on the horizontal development of unconventional plays in the Permian Basin and the cost-efficient management of shallow-decline oil and natural gas wells in the Permian Basin, East Texas, Rocky Mountain and Mid-Continent regions. The accompanying financial statements have been prepared on the accrual basis of accounting whereby revenues are recognized when earned, and expenses are recognized when incurred.
Going Concern	Going Concern Legacy has significant obligations and commitments coming due in the near term. The Credit Agreement (as defined in Note 3) matures on May 31, 2019 and as of December 31, 2018, Legacy had borrowings of $541.0 million and availability under the Credit Agreement of $32.9 million . In addition, Legacy received a temporary waiver under the Term Loan Credit Agreement (as defined in Note 3) of its requirement to deliver fiscal year 2018 audited financial statements without a "going concern" or like qualification or exception through May 31, 2019. Due to the short-term nature of this waiver and the anticipation that we will be in violation of this covenant upon expiry of the waiver, Legacy has determined that the total borrowings outstanding under the Term Loan Credit Agreement of $338.6 million are due in the near term and have thus recorded these as a current liability. Without additional sources of capital or a significant restructuring of its balance sheet, the maturity of the Credit Agreement raises substantial doubt about Legacy's ability to continue as a going concern, which means that Legacy may be unable to continue operations for the foreseeable future or realize assets and discharge liabilities in the ordinary course of operation.The consolidated financial statements do not include any adjustments that might result from the outcome of the going concern uncertainty. In order to improve its liquidity position, Legacy is currently evaluating financial, transactional and other strategic alternatives. There can be no assurance that sufficient liquidity can be raised from any one or more of these transactions or that these transactions can be consummated within the period needed to meet our obligations.
Corporate Reorganization	Corporate Reorganization On September 20, 2018, we completed the transactions contemplated by the Amended and Restated Agreement and Plan of Merger (the “Merger Agreement”), dated July 9, 2018, by and among Legacy Inc., Legacy LP, Legacy Reserves GP, LLC (the “General Partner”) and Legacy Reserves Merger Sub LLC, a wholly owned subsidiary of Legacy Inc. (“Merger Sub”), and the GP Purchase Agreement, dated March 23, 2018, by and among Legacy Inc., the General Partner, Legacy LP, Lion GP Interests, LLC, Moriah Properties Limited, and Brothers Production Properties, Ltd., Brothers Production Company, Inc., Brothers Operating Company, Inc., J&W McGraw Properties, Ltd., DAB Resources, Ltd. and H2K Holdings, Ltd. (such transactions referred to herein collectively as the “Corporate Reorganization”). Upon the consummation of the Corporate Reorganization: • Legacy Inc., which prior to the Corporate Reorganization, was a wholly owned subsidiary of the General Partner, acquired all of the issued and outstanding limited liability company interests in the General Partner and became the sole member of the General Partner with the General Partner becoming a subsidiary of Legacy Inc.; and • Legacy LP merged with Merger Sub, with Legacy LP continuing as the surviving entity and as a subsidiary of Legacy Inc. (the “Merger”), the limited partner interests of Legacy LP, other than the incentive distribution units in Legacy LP, were exchanged for shares of Legacy Inc.’s common stock, par value $0.01 (“common stock”) and the general partner interest remained outstanding. The Corporate Reorganization was accounted for under ASC 805 as a combination of entities under common control. As such, the assets and liabilities of the Partnership were recognized at their carrying values in Legacy Inc.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. Legacy routinely assesses the financial strength of its customers. Bad debts are recorded based on an account-by-account review. Accounts are written off after all means of collection have been exhausted and potential recovery is considered remote. Legacy does not have any off-balance-sheet credit exposure related to its customers (see Note 12).
Oil and Natural Gas Properties and Oil, NGLs and Natural Gas Reserve Quantities	Oil and Natural Gas Properties Legacy accounts for oil and natural gas properties using the successful efforts method. Under this method of accounting, costs relating to the acquisition and development of proved areas are capitalized when incurred. The costs of development wells are capitalized whether productive or non-productive. Leasehold acquisition costs are capitalized when incurred. If proved reserves are found on an unproved property, leasehold cost is transferred to proved properties. Exploration dry holes are charged to expense when it is determined that no commercial reserves exist. Other exploration costs, including personnel costs, geological and geophysical expenses and delay rentals for oil and natural gas leases, are charged to expense when incurred. The costs of acquiring or constructing support equipment and facilities used in oil and gas producing activities are capitalized. Production costs are charged to expense as incurred and are those costs incurred to operate and maintain our wells and related equipment and facilities. Depreciation and depletion of producing oil and natural gas properties is recorded based on units of production. Acquisition costs of proved properties are amortized on the basis of all proved reserves, developed and undeveloped, and capitalized development costs (wells and related equipment and facilities) are amortized on the basis of proved developed reserves. As more fully described below, proved reserves are estimated annually by Legacy’s independent petroleum engineer, LaRoche Petroleum Consultants, Ltd. ("LaRoche"), and are subject to future revisions based on availability of additional information. Legacy’s in-house reservoir engineers prepare an updated estimate of reserves each quarter. Depletion is calculated each quarter based upon the latest estimated reserves data available. As discussed in Note 13, asset retirement costs are recognized when the asset is placed in service, and are amortized over proved developed reserves using the units of production method. Asset retirement costs are estimated by Legacy’s engineers using existing regulatory requirements and anticipated future inflation rates. Upon sale or retirement of complete fields of depreciable or depletable property, the book value thereof, less proceeds from sale or salvage value, is charged to income. On sale or retirement of an individual well the proceeds are credited to accumulated depletion and depreciation. Oil and natural gas properties are reviewed for impairment when facts and circumstances indicate that their carrying value may not be recoverable. Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. If net capitalized costs exceed estimated undiscounted future net cash flows, the measurement of impairment is based on estimated fair value, using estimated discounted future net cash flows. Significant inputs used to determine the fair values of proved properties include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in Legacy's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. For the year ended December 31, 2018 , Legacy recognized $58.7 million of impairment expense in 50 separate producing fields, due primarily to the further decline in oil and natural gas futures prices, increased expenses and well performance during the year ended December 31, 2018 , which decreased the expected future cash flows below the carrying value of the assets. For the year ended December 31, 2017 , Legacy recognized $37.3 million of impairment expense, in 47 separate producing fields, due primarily to the further decline in oil and natural gas futures prices, increased expenses and well performance during the year ended December 31, 2017 , which decreased the expected future cash flows below the carrying value of the assets. For the year ended December 31, 2016 , Legacy recognized $61.8 million of impairment expense, due primarily to well performance and the further decline in commodity prices during the year ended December 31, 2016, which decreased the expected future cash flows below the carrying value of the assets. Unproven properties that are individually significant are assessed for impairment and if considered impaired are charged to expense when such impairment is deemed to have occurred. Legacy recognized $9.3 million of impairment of unproven properties during the year ended December 31, 2018 . Legacy did not recognize impairment expense on unproved properties during the years ended December 31, 2017 and 2016 . (f) Oil, NGLs and Natural Gas Reserve Quantities Legacy’s estimates of proved reserves are based on the quantities of oil, NGLs and natural gas that engineering and geological analyses demonstrate, with reasonable certainty, to be recoverable from established reservoirs in the future under current operating and economic parameters. LaRoche prepares a reserve and economic evaluation of all Legacy’s properties on a case-by-case basis utilizing information provided to it by Legacy and information available from state agencies that collect information reported to it by the operators of Legacy’s properties. The estimates of Legacy’s proved reserves have been prepared and presented in accordance with SEC rules and accounting standards. Reserves and their relation to estimated future net cash flows impact Legacy’s depletion and impairment calculations. As a result, adjustments to depletion and impairment are made concurrently with changes to reserve estimates. Legacy prepares its reserve estimates, and the projected cash flows derived from these reserve estimates, in accordance with SEC guidelines. The independent engineering firm described above adheres to the same guidelines when preparing the reserve report. The accuracy of Legacy’s reserve estimates is a function of many factors including the quality and quantity of available data, the interpretation of that data, the accuracy of various mandated economic assumptions, and the judgments of the individuals preparing the estimates. Legacy’s proved reserve estimates are a function of many assumptions, all of which could deviate significantly from actual results. As such, reserve estimates may materially vary from the ultimate quantities of oil, NGLs and natural gas eventually recovered.
Income Taxes	Income Taxes Prior to consummation of the Corporate Reorganization on September 20, 2018, Legacy LP was treated as a partnership for federal and state income tax purposes, in which the taxable income or loss was passed through to its unitholders. Legacy LP was subject to Texas margin tax and certain of Legacy LP’s subsidiaries were c-corporations subject to federal and state income taxes. Therefore, with the exception of the state of Texas and certain subsidiaries, Legacy LP did not directly pay federal and state income taxes and recognition was not given to federal and state income taxes for its operations. Effective upon consummation of the Corporate Reorganization, Legacy Inc. became subject to federal and state income taxes as a c-corporation. As such, we account for income taxes, as required, under the liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and net operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in net income or loss in the period that includes the enactment date. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Our policy is to record interest and penalties relating to uncertain tax positions in income tax expense. At December 31, 2018 , we did not have any accrued liability for uncertain tax positions and do not anticipate recognition of any significant liabilities for uncertain tax positions during the next 12 months.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Legacy uses derivative financial instruments to achieve more predictable cash flows by reducing its exposure to oil and natural gas price fluctuations and interest rate changes. Legacy does not specifically designate derivative instruments as cash flow hedges, even though they reduce its exposure to changes in oil and natural gas prices and interest rates. Therefore, Legacy records the change in the fair market values of oil and natural gas derivatives in current earnings. Changes in the fair values of interest rate derivatives are recorded in interest expense (see Notes 10 and 11).
Use of Estimates	Use of Estimates Management of Legacy has made a number of estimates and assumptions relating to the reporting of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities to prepare these consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. Actual results could differ materially from those estimates. Estimates which are particularly significant to the consolidated financial statements include estimates of oil and natural gas reserves, valuation of derivatives, impairment of oil and natural gas properties, depreciation, depletion and amortization, asset retirement obligations and accrued revenues.
Revenue Recognition	Revenue Recognition On January 1, 2018, Legacy adopted ASU No. 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”) using the modified retrospective method of transition applied to all contracts. ASU 2014-09 created ASC 606, Revenue from Contracts with Customers (ASC 606). Legacy enters into contracts with customers to sell its produced oil, natural gas and NGLs. Revenue attributable to these contracts is recognized in accordance with the five-step revenue recognition model prescribed in ASC 606. Specifically, revenue is recognized when Legacy’s performance obligations under these contracts are satisfied, which generally occurs when control of the oil, natural gas and NGLs transfers to the purchaser and collectability is reasonably assured. Given the nature of Legacy’s products sold, Legacy has concluded that control transfers to its customers at a point in time. In accordance with ASC 606, Legacy considers the following indicators of the transfer of control to determine the point in time at which control transfers to its customers: (i) Legacy has a present right to payment for the asset; (ii) the customer has legal title to the asset; (iii) Legacy has transferred physical possession of the asset; and (iv) the customer has the significant risks and rewards of ownership. Oil Sales Legacy's oil sales contracts are generally structured such that Legacy sells its oil production to the purchaser at a contractually specified delivery point at or near the wellhead. The crude oil production is priced on the delivery date based upon prevailing index prices less certain deductions related to oil quality and physical location. Legacy recognizes revenue when control transfers to the purchaser upon delivery at or near the wellhead based on the net price received from purchaser. Natural Gas and NGL Sales Under Legacy's gas processing contracts, Legacy delivers wet gas to a midstream processing entity at the wellhead or the inlet of the midstream processing entity’s system. The midstream processing entity processes the natural gas and remits proceeds to Legacy for the resulting sales of NGLs and residue gas. Under this contract structure, Legacy has determined that the midstream processing entity represents Legacy’s customer, and, consequently, Legacy recognizes revenue when control transfers to the midstream processing entity upon delivery. The amount of revenue recognized is based on the net amount of the proceeds received from the midstream processing entity, which is generally tied to the prevailing index prices for residue gas and NGLs less deductions for gathering, processing, transportation and other expenses. Under Legacy's dry gas sales that do not require processing, Legacy sells its natural gas production to third party purchasers at a contractually specified delivery point at or near the wellhead. Pricing provisions are tied to a market index, with certain deductions based on, among other factors, whether a well delivers to a gathering or transmission line, quality of natural gas, and prevailing supply and demand conditions. Legacy recognizes revenue when control transfers to its third party purchasers upon delivery of the natural gas based on the relevant index price net of deductions. Estimation To the extent actual product volumes and related prices are unavailable for a given reporting period because of timing or information not received from third parties, the expected sales volumes and prices for those properties are estimated and recorded as “Accounts receivable - oil and natural gas” in the accompanying consolidated balance sheets. Refer to Note 4 - Revenue from Contracts with Customer for additional information. Imbalances Natural gas imbalances occur when Legacy sells more or less than its entitled ownership percentage of total natural gas production. Any amount received in excess of its share is treated as a liability. If Legacy receives less than its entitled share, the underproduction is recorded as a receivable. Legacy did not have any significant natural gas imbalance positions as of December 31, 2018 , 2017 and 2016 .
Investments	Investments Undivided interests in oil and natural gas properties owned through joint ventures are consolidated on a proportionate basis. Investments in entities where Legacy exercises significant influence, but not a controlling interest, are accounted for by the equity method. Under the equity method, Legacy’s investments are stated at cost plus the equity in undistributed earnings and losses after acquisition.
Environmental	Environmental Legacy is subject to extensive federal, state and local environmental laws and regulations. These laws, which are frequently changing, regulate the discharge of materials into the environment and may require Legacy to remove or mitigate the environmental effects of the disposal or release of petroleum or chemical substances at various sites. Environmental expenditures are expensed or capitalized depending on their future economic benefit. Expenditures that relate to an existing condition caused by past operations and that have no future economic benefits are expensed. Liabilities for expenditures of a non-capital nature are recorded when environmental assessment and/or remediation are probable, and the costs can be reasonably estimated. Such liabilities are generally undiscounted unless the timing of cash payments is fixed and readily determinable.
Income (Loss) Per Share	Income (Loss) Per Share Basic income (loss) per share amounts are calculated using the weighted average number of shares outstanding during each period. Diluted income (loss) per share also gives effect to dilutive unvested restricted shares (calculated based upon the treasury stock method) (see Note 14). In accordance with ASC 805, income (loss) per share amounts for historical periods have been recomputed to reflect shares issued in the Corporate Reorganization
Segment Reporting	Segment Reporting Legacy’s management initially treats each new acquisition of oil and natural gas properties as a separate operating segment. Legacy aggregates these operating segments into a single segment for reporting purposes.
Unit-Based Compensation	Share-Based Compensation Concurrent with its formation on March 15, 2006, a Long-Term Incentive Plan (“Legacy LP LTIP”) for Legacy was created. Due to Legacy’s history of cash settlements for option exercises unit appreciation rights ("UARs") and certain phantom unit awards, Legacy accounted for these awards under the liability method, which requires Legacy to recognize the fair value of each unit award at the end of each period. Expense or benefit is recognized as the fair value of the liability changes from period to period. Legacy accounted for executive phantom unit and restricted unit awards under the equity method. Pursuant to the terms of the Corporate Reorganization, the Legacy LP LTIP was terminated. On September 19, 2018, the Legacy Inc. 2018 Omnibus Incentive Plan (the "Legacy Inc, LTIP") was approved by the former unitholders of Legacy LP in connection wiht the Corporate Reorganization. Legacy accounts for the restricted stock units ("RSUs") under the equity method. Legacy’s shares outstanding, as reflected in the accompanying consolidated balance sheet at December 31, 2018 , do not include 7,302,809 shares related to unvested RSUs.
Restricted Cash	Restricted Cash Restricted cash of $3.3 million and $3.2 million as of December 31, 2018 and 2017 , respectively, is recorded in the "Prepaid expenses and other current assets" line. The restricted cash amounts represent various deposits to secure the performance of contracts, surety bonds and other obligations incurred in the ordinary course of business.
Prior Year Financial Statement Presentation	Prior Year Financial Statement Presentation Certain prior year balances have been reclassified to conform to the current year presentation of balances as stated in this annual report on Form 10-K.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, "Leases" ("ASU 2016-02"). ASU 2016-02 establishes a right-of-use (ROU) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms at commencement longer than twelve months. Legacy engaged a third party consultant to assist with its implementation of ASU 2016-02. Leases will be classified as either finance or operating, with that classification affecting the pattern of expense recognition in the income statement. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Legacy will adopt ASU 2016-02 using a modified retrospective approach in the first quarter of 2019 (that is, the period of adoption). At transition, Legacy will utilize the package of practical expedients provided in ASU 2016-02 that allow companies, among other things, to not reassess contracts that commenced prior to adoption. In addition, Legacy expects to utilize the practical expedient to not evaluate land easements that existed or expired before the adoption of ASU 2016-02 and that were not previously accounted for as leases under currently effective lease accounting guidance. Legacy is evaluating the provisions of ASU 2016-02 and finalizing the impact it will have on its consolidated results of operations, financial position and financial disclosures. Legacy believes that the new guidance will impact its consolidated balance sheet due to the recognition of right-of-use assets and lease liabilities that are not recognized under currently effective guidance (for example, operating leases). The adjustments that will be required upon implementation of ASU 2016-02, which Legacy anticipates to be less than $15 million, have not been finalized. Legacy commonly enters into lease agreements in support of its operations for assets such as office space, vehicles, drilling rigs, compressors and other well equipment. In its efforts to determine the impact of ASU 2016-02, Legacy developed an implementation approach that included educating key stakeholders within the organization, analyzing systems reports to identify the types and volume of contracts that may meet the definition of a lease and performing a detailed review of material contracts identified through that analysis. Legacy is also implementing a financial lease accounting system solution to facilitate compliance with ASU 2016-02.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of components of accrued oil and natural gas liabilities	Below are the components of accrued oil and natural gas liabilities as of December 31, 2018 and 2017 . December 31, 2018 2017 (In thousands) Accrued capital expenditures $ 24,690 $ 33,198 Accrued lease operating expense 41,227 18,179 Revenue payable to joint interest owners 22,750 18,510 Accrued ad valorem tax 5,255 5,807 Other 4,964 5,624 $ 98,886 $ 81,318

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
Long-Term Debt (Tables)	Dec. 31, 2018
Debt Instrument [Line Items]
Schedule of long-term debt	Debt consists of the following at December 31, 2018 and 2017 : December 31, 2018 2017 (In thousands) Current debt Credit Facility due 2019 $ 541,000 $ — Second Lien Term Loans due 2020 338,626 — Unamortized debt issuance costs (17,332 ) — Unamortized discount on Second Lien Term Loans (5,648 ) — Total current debt, net $ 856,646 $ — Long-term debt Credit Facility due 2019 $ — $ 499,000 Second Lien Term Loans due 2020 — 205,000 8% Senior Notes due 2020 208,885 232,989 6.625% Senior Notes due 2021 131,279 432,656 8% Convertible Senior Notes due 2023 128,103 — $ 468,267 $ 1,369,645 Unamortized discount on Senior Notes (31,517 ) (13,101 ) Unamortized debt issuance costs (3,827 ) (9,775 ) Total long-term debt, net $ 432,923 $ 1,346,769 Total debt, net $ 1,289,569 $ 1,346,769
Convertible debt	In addition, if a holder exercises its right to convert on or prior to September 19, 2019, such holder will receive an early conversion payment, in cash, per $1,000 principal amount as follows: Early Conversion Date Early Conversion Payment December 1, 2018 through May 31, 2019 $64.22 June 1, 2019 through September 19, 2019 $24.22
8% Senior Notes due 2020
Debt Instrument [Line Items]
Schedule of debt redemption	Legacy has the option to redeem the 2020 Senior Notes, in whole or in part, at par together with any accrued and unpaid interest, if any, to the date of redemption
6.625% Senior Notes due 2021
Debt Instrument [Line Items]
Schedule of debt redemption	Legacy will have the option to redeem the 2021 Senior Notes, in whole or in part, at par together with any accrued and unpaid interest, if any, to the date of redemption.

Impact of ASC 606 Adoption (Tab

Impact of ASC 606 Adoption (Tables)	12 Months Ended
Impact of ASC 606 Adoption (Tables)	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The impact of adoption on Legacy's current period results is as follows (in thousands): Twelve months ended December 31, 2018 Under ASC 606 Under ASC 605 Change (In thousands) Revenues: Oil Sales $ 375,444 $ 375,244 $ (200 ) Natural gas liquids (NGL) sales 27,750 27,232 (518 ) Natural gas sales 151,667 145,135 (6,532 ) $ 554,861 $ 547,611 $ (7,250 ) Costs and expenses: Oil and natural gas production 200,285 193,035 (7,250 ) Net income 43,833 43,833 $ — Partners' deficit, as of January 1, 2018 271,687 271,687 $ —

Revenues from Contracts with _2

Revenues from Contracts with Customers (Tables)	12 Months Ended
Revenues from Contracts with Customers (Tables)	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Revenue attributable to each of Legacy's identified revenue streams is disaggregated in the table below. Twelve Months Ended December 31, 2018 (In thousands) Revenues: Oil sales $ 375,444 Natural gas liquids (NGL) sales 27,750 Natural gas sales 151,667 Total revenues $ 554,861

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis	The following table sets forth by level within the fair value hierarchy Legacy’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2018 and 2017 : December 31, 2018 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Total Fair Value Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Description (Level 1) (Level 2) (Level 3) (In thousands) Assets: Current Commodity derivatives $ — $ 69,288 $ — $ 69,288 $ (4,670 ) $ 64,618 Interest rate derivatives — 2,044 — 2,044 — 2,044 Noncurrent Commodity derivatives — 3,473 — 3,473 (338 ) 3,135 Interest rate derivatives — — — — — — Liabilities: Current Commodity derivatives — (4,670 ) — (4,670 ) 4,670 — Noncurrent Commodity derivatives — (888 ) — (888 ) 338 (550 ) $ — $ 69,247 $ — $ 69,247 $ — $ 69,247 December 31, 2017 Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Total Fair Value Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Description (Level 1) (Level 2) (Level 3) (In thousands) Assets: Current Commodity derivatives $ — $ 19,792 $ — $ 19,792 $ (7,204 ) $ 12,588 Interest rate derivatives — 837 — 837 (1 ) 836 Noncurrent Commodity derivatives — 14,278 — 14,278 (1,460 ) 12,818 Interest rate derivatives — 1,281 — 1,281 1,281 Liabilities: Current Commodity derivatives — (21,027 ) (4,191 ) (25,218 ) 7,204 (18,014 ) Interest rate derivatives — (1 ) — (1 ) 1 — LTIP liability — (1,947 ) — (1,947 ) (1,947 ) Noncurrent Commodity derivatives — (1,637 ) (897 ) (2,534 ) 1,460 (1,074 ) Interest rate derivatives — — — $ — $ 11,576 $ (5,088 ) $ 6,488 $ — $ 6,488
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3	The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy: Significant Unobservable Inputs (Level 3) December 31, 2018 2017 2016 (In thousands) Beginning balance $ (5,088 ) $ 8 $ (4,493 ) Total gains (losses) 30,571 (5,073 ) 253 Settlements (22,379 ) (23 ) 4,248 Transfers (3,104 ) (a) — — Ending balance $ — $ (5,088 ) $ 8 Gains (losses) included in earnings relating to derivatives still held as of December 31, 2018, 2017 and 2016 $ — $ (5,088 ) $ 68 ____________________ (a) Due to the lack of a historical market, we have historically accounted for our Midland-to-Cushing crude oil differential swaps as Level 3. However, with recent widening differentials, an active market has been created in which quoted prices are readily observable. As such, we have determined that the inputs used to value these derivatives now classify as Level 2 and transferred the value of the derivatives into Level 2.
Schedule of fair value measurements of proved oil and natural gas properties	Nonrecurring fair value measurements of proved oil and natural gas properties during the years ended December 31, 2018 and 2017 consist of adjustments of the carrying value oil and natural gas properties to their fair value of $43.9 million and $31.9 million , respectively. Legacy periodically reviews oil and natural gas properties for impairment when facts and circumstances indicate that their carrying value may not be recoverable. During the year ended December 31, 2018 , Legacy incurred impairment charges of $58.7 million as oil and natural gas properties with a net cost basis of $102.6 million were written down to their fair value of $43.9 million . During the year ended December 31, 2017 , Legacy incurred impairment charges of $37.3 million as oil and natural gas properties with a net cost basis of $69.1 million were written down to their fair value of $31.8 million . In order to determine whether the carrying value of an asset is recoverable, Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. If the net capitalized cost exceeds the undiscounted future net cash flows, Legacy writes the net cost basis down to the discounted future net cash flows, which is management's estimate of fair value. Significant inputs used to determine the fair value include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices; and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in the Company's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. The inputs used by management for the fair value measurements utilized in this review include significant unobservable inputs, and therefore, the fair value measurements employed are classified as Level 3 for these types of assets. The remaining $9.3 million of impairment during the year ended December 31, 2018 represented impairment of unproved properties acquired since 2010 that are no longer viable for development.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
Derivative Financial Instruments (Tables)	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of reconciliation of the changes in fair value of Legacy's commodity derivatives	The following table sets forth a reconciliation of the changes in fair value of Legacy's commodity derivatives for the years ended December 31, 2018 , 2017 , and 2016 . December 31, 2018 2017 2016 (In thousands) Beginning fair value of commodity derivatives $ 6,318 $ 12,698 $ 118,427 Total gain (loss) crude oil derivatives 54,380 (15,325 ) (9,410 ) Total gain (loss) natural gas derivatives (5,208 ) 33,101 (31,814 ) Crude oil derivative cash settlements paid (received) 16,845 (11,840 ) (37,464 ) Natural gas derivative cash settlements received (5,130 ) (12,316 ) (27,041 ) Ending fair value of commodity derivatives $ 67,205 $ 6,318 $ 12,698
Schedule of notional amounts of outstanding derivative positions	As of December 31, 2018 , Legacy had the following NYMEX WTI crude oil swaps paying floating prices and receiving fixed prices for a portion of its future oil production as indicated below: Calendar Year Volumes (Bbls) Average Price per Bbl Price Range per Bbl 2019 3,285,000 $61.33 $57.15 - $67.65 As of December 31, 2018 , Legacy had the following Midland-to-Cushing crude oil differential swaps paying a floating differential and receiving a fixed differential for a portion of its future oil production as indicated below: Calendar Year Volumes (Bbls) Average Price per Bbl Price Range per Bbl 2019 2,193,000 $(3.62) $(5.60) - $(1.15) As of December 31, 2018 , Legacy had the following Midland-to-Cushing crude oil differential enhanced swaps paying a floating differential and receiving a fixed differential for a portion of its future oil production as indicated below: Calendar Year Volumes (Bbls) Average Short Call Price per Bbl Average Swap Price per Bbl 2019 $1,460,000 $70.00 $(2.91) As of December 31, 2018 , Legacy had the following NYMEX Henry Hub natural gas swaps paying floating natural gas prices and receiving fixed prices for a portion of its future natural gas production as indicated below: Average Price Range Calendar Year Volumes (MMBtu) Price per MMBtu per MMBtu 2019 37,175,000 $3.36 $3.05 - $4.40 As of December 31, 2018 , Legacy had the following Henry Hub NYMEX to CIG natural gas differential swaps paying a floating differential and receiving a fixed differential for a portion of its future natural gas production as indicated below: Average Price Range Calendar Year Volumes (MMBtu) Price per MMBtu per MMBtu 2019 3,600,000 $(0.47) $(0.46) - $(0.49)
Schedule of total impact on interest expense from the mark-to-market and settlements	The total impact on interest expense from the mark-to-market and settlements was as follows: December 31, 2018 2017 2016 (In thousands) Beginning fair value of interest rate swaps $ 2,117 $ 183 $ (362 ) Total gain (loss) loss on interest rate swaps 1,213 1,168 (2,108 ) Cash settlements paid (1,286 ) 766 2,653 Ending fair value of interest rate swaps $ 2,044 $ 2,117 $ 183
Schedule of interest rate swap liabilities	The table below summarizes the interest rate swap assets and liabilities as of December 31, 2018 . Weighted Average Fixed Effective Maturity Estimated Fair Market Value at December 31, Notional Amount Rate Date Date 2018 (Dollars in thousands) $235,000 1.363 % 9/1/2015 9/1/2019 2,044 Total fair value of interest rate derivatives $ 2,044

Sales to Major Customers (Table

Sales to Major Customers (Tables)	12 Months Ended
Sales to Major Customers (Tables)	Dec. 31, 2018
Risks and Uncertainties [Abstract]
Schedule of revenue by major customer	For the year ended December 31, 2018 and 2017 , Legacy sold oil, NGL and natural gas production representing 10% or more of total revenues to the purchasers as detailed in the table below. For the year ended December 31, 2016 , Legacy did not sell oil, NGL or natural gas production representing 10% or more of total revenue to any one customer. 2018 2017 2016 Plains Marketing, LP 20% 10% 6% Rio Energy International Inc 13% 9% 3%

Asset Retirement Obligation (Ta

Asset Retirement Obligation (Tables)	12 Months Ended
Asset Retirement Obligation (Tables)	Dec. 31, 2018
Asset Retirement Obligation [Abstract]
Schedule of changes in asset retirement obligations	The following table reflects the changes in the ARO during the years ended December 31, 2018 , 2017 and 2016 . December 31, 2018 2017 2016 (In thousands) Asset retirement obligation — beginning of period $ 274,686 $ 272,148 $ 286,405 Liabilities incurred with properties acquired 226 62 24 Liabilities incurred with properties drilled 65 39 1 Liabilities settled during the period (2,258 ) (1,891 ) (2,351 ) Liabilities associated with properties sold (27,673 ) (8,464 ) (24,605 ) Current period accretion 12,568 12,792 12,674 Current period revisions to previous estimates (4,880 ) — — Asset retirement obligation — end of period $ 252,734 $ 274,686 $ 272,148

Stockholders' Deficit_Partner_2

Stockholders' Deficit/Partners' Deficit (Tables)	12 Months Ended
Stockholders' Deficit/Partners' Deficit (Tables)	Dec. 31, 2018
Equity [Abstract]
Schedule of computation of basic and diluted income (loss) per unit	The following table sets forth the computation of basic and diluted loss per share / unit: Years Ended December 31, 2018 2017 2016 (In thousands) Income/(loss) $ 43,833 $ (53,897 ) $ (55,820 ) Income/(loss) attributable to shareholders $ 43,833 $ (53,897 ) $ (55,820 ) Weighted average number of shares outstanding 105,087 100,049 98,249 Effect of dilutive securities: Restricted and phantom units — — — Weighted average units and potential units outstanding 105,087 100,049 98,249 Basic and diluted income/(loss) per share $ 0.42 $ (0.54 ) $ (0.57 )

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
Stock-Based Compensation (Tables)	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of option and UAR activity	A summary of UAR activity for the year ended December 31, 2018 , 2017 and 2016 is as follows: Units Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2016 936,116 $ 20.61 Expired (21,067 ) $ 16.07 Forfeited (30,503 ) $ 19.80 Outstanding at December 31, 2016 884,546 $ 20.75 3.67 $ — UARs exercisable at December 31, 2016 570,369 $ 24.38 2.77 $ — Outstanding at January 1, 2017 884,546 $ 20.75 Expired (147,024 ) $ 24.50 Forfeited (15,501 ) $ 13.91 Outstanding at December 31, 2017 722,021 $ 20.13 3.29 $ — UARs exercisable at December 31, 2017 592,522 $ 23.23 2.99 $ — Outstanding at January 1, 2018 722,021 $ 20.13 Expired (90,844 ) $ 4.69 Forfeited (631,177 ) $ 22.35 Outstanding at December 31, 2018 — $ — 0.00 $ — UARs exercisable at December 31, 2018 — $ — 0.00 $ —
Schedule of status of the Partnership’s non-vested UARs	The following table summarizes the status of Legacy’s non-vested UARs since January 1, 2018 : Non-Vested UARs Number of Units Weighted- Average Exercise Price Non-vested at January 1, 2018 129,499 $ 5.97 Vested (124,832 ) 5.99 Forfeited (4,667 ) 5.25 Non-vested at December 31, 2018 — $ —
Schedule of RSU activity	A summary of RSU activity for the year ended December 31, 2018 is as follows: Number of Restricted Stock Units Weighted Average Grant Date Fair Value Outstanding at January 1, 2018 — $ — Granted 7,523,720 $ 4.89 Expired — $ — Forfeited (220,911 ) $ 5.14 Outstanding at December 31, 2018 7,302,809 $ 4.88

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The income tax expense (benefit) consists of: Years Ended December 31, 2018 2017 2016 (In thousands) Current: Federal $ 140 $ 1,911 $ 1,183 State (147 ) (52 ) (193 ) Total current income tax expense (benefit) (7 ) 1,859 990 Deferred: Federal $ 1,270 $ (464 ) $ (782 ) State 1,705 3 1,021 Total deferred income tax expense (benefit) 2,975 (461 ) 239 Total income tax expense $ 2,968 $ 1,398 $ 1,229
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the federal statutory tax rate to the effective tax rate is as follows: Years Ended December 31, 2018 2017 2016 Tax at federal statutory rate 21.0 % 35.0 % 35.0 % Partnership loss not subject to federal tax 16.6 % (36.1 )% (35.7 )% Federal rate change — % (1.6 )% — % 2023 Convertible Notes issuance 7.4 % — % — % Valuation allowance adjustment (44.1 )% — % — % Texas margins tax 6.1 % (1.6 )% (2.0 )% Other (0.7 )% 1.6 % 0.4 % Effective tax rate 6.3 % (2.7 )% (2.3 )%
Schedule of Deferred Tax Assets and Liabilities	Deferred income tax balances representing the tax effect of temporary differences between the financial statement carrying amounts and the tax basis of assets and liabilities are as follows: December 31, 2018 2017 (In thousands) Deferred tax assets: Oil and natural gas properties $ 91,948 $ 1,840 Net operating losses 12,961 — Interest expense 6,668 — Other — 1,176 Total deferred tax assets 111,577 3,016 Deferred tax liabilities Hedging activities (15,934 ) (32 ) Other (1,585 ) (11 ) Total deferred tax liabilities (17,519 ) (43 ) Valuation allowance (94,058 ) — Net deferred tax assets $ — $ 2,973

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Other Narrative (Details)	Sep. 20, 2018USD ($)$ / shares	Dec. 31, 2018USD ($)field$ / shares	Dec. 31, 2017USD ($)field	Dec. 31, 2016USD ($)	Sep. 30, 2018USD ($)shares	May 13, 2014USD ($)	Apr. 01, 2014USD ($)	May 28, 2013USD ($)	Dec. 04, 2012USD ($)
Property, Plant and Equipment [Line Items]
Common stock, par value (in USD per share) \| $ / shares	$ 0.01	$ 0.01
Impairment expense		$ 67,978,000	$ 37,283,000	$ 61,796,000
Number of impaired fields \| field		50	47
Impairment of oil and gas properties		$ 9,300,000
Unproved Oil and Gas Properties
Property, Plant and Equipment [Line Items]
Impairment of oil and gas properties				$ 0
Second Lien Term Loans due 2020
Property, Plant and Equipment [Line Items]
Long-term debt, gross, current		$ 338,626,000	$ 0
8% Notes Due 2020, Tranche 1 \| Senior notes
Property, Plant and Equipment [Line Items]
Extinguishment of debt	$ 21,004,000
8% Notes Due 2023, Tranche 1 \| Senior notes
Property, Plant and Equipment [Line Items]
Aggregate principal amount	21,004,000
8% Convertible Senior Notes due 2023
Property, Plant and Equipment [Line Items]
Common stock, shares issued \| shares					105,020
6.625% Percent Notes Due 2021, Tranche 2 \| Senior notes
Property, Plant and Equipment [Line Items]
Extinguishment of debt	109,000,000
8% Notes Due 2023, Tranche 2 \| Senior notes
Property, Plant and Equipment [Line Items]
Aggregate principal amount	109,000,000
Senior notes \| 8% Senior Notes due 2020
Property, Plant and Equipment [Line Items]
Stated interest rate		8.00%
Aggregate principal amount		$ 3,100,000			$ 21,004,000				$ 300,000,000
Senior notes \| 8% Convertible Senior Notes due 2023
Property, Plant and Equipment [Line Items]
Stated interest rate		8.00%
Aggregate principal amount		$ 1,901,000
Senior notes \| 6.625% Senior Notes due 2021
Property, Plant and Equipment [Line Items]
Stated interest rate		6.625%				6.625%
Aggregate principal amount	$ 109,000,000					$ 300,000,000		$ 250,000,000
Credit Facility due 2019
Property, Plant and Equipment [Line Items]
Long-term debt, gross, current		$ 541,000,000	$ 0
Remaining borrowing capacity		$ 32,900,000
Maximum borrowing capacity							$ 1,500,000,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Unit-Based Compensation (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted stock units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive restricted units excluded from computation of EPS (in shares)	7,302,809	241,373	484,447

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Accrued Oil and Natural Gas Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued capital expenditures	$ 24,690	$ 33,198
Accrued lease operating expense	41,227	18,179
Revenue payable to joint interest owners	22,750	18,510
Accrued ad valorem tax	5,255	5,807
Other	4,964	5,624
Accrued oil and natural gas liabilities	$ 98,886	$ 81,318

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Restricted cash	$ 3.3	$ 3.2	$ 3.6

Fair Values of Financial Inst_2

Fair Values of Financial Instruments (Details) - Senior notes - USD ($) $ in Millions	Dec. 31, 2018	May 13, 2014
8% Senior Notes due 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	8.00%
8% Senior Notes due 2020 \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes payable	$ 97.8
6.625% Senior Notes due 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	6.625%	6.625%
6.625% Senior Notes due 2021 \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes payable	$ 57.9
8% Convertible Senior Notes due 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	8.00%
8% Convertible Senior Notes due 2023 \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes payable	$ 42.3

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	May 13, 2014
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (17,332)	$ 0
Total current debt, net	856,646	0
Long-term debt, gross	468,267	1,369,645
Unamortized discount on Senior Notes	(31,517)	(13,101)
Unamortized debt issuance costs	(3,827)	(9,775)
Total long-term debt, net	432,923	1,346,769
Total debt, net	1,289,569	1,346,769
Second Lien Term Loans due 2020
Debt Instrument [Line Items]
Long-term debt, gross, current	338,626	0
Long-term debt, gross	0	205,000
Unamortized discount on Senior Notes	(5,648)	0
Senior notes \| 8% Senior Notes due 2020
Debt Instrument [Line Items]
Long-term debt, gross	208,885	232,989
Total debt, net	$ 5,300
Stated interest rate	8.00%
Senior notes \| 6.625% Senior Notes due 2021
Debt Instrument [Line Items]
Long-term debt, gross	$ 131,279	432,656
Stated interest rate	6.625%		6.625%
Senior notes \| 8% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Long-term debt, gross	$ 128,103	0
Stated interest rate	8.00%
Credit Facility due 2019
Debt Instrument [Line Items]
Long-term debt, gross, current	$ 541,000	0
Long-term debt, gross	$ 0	$ 499,000

Long-Term Debt - Credit Facilit

Long-Term Debt - Credit Facility (Details)	Apr. 01, 2014USD ($)	Dec. 31, 2018USD ($)	Mar. 21, 2019USD ($)	Jan. 01, 2019	Oct. 01, 2018	Sep. 20, 2018	Dec. 31, 2017USD ($)	Oct. 05, 2017USD ($)	Jul. 01, 2017	Oct. 25, 2016
Credit Facility due 2019
Line of Credit Facility [Line Items]
Expiration period	5 years
Maximum borrowing capacity	$ 1,500,000,000
Current borrowing capacity								$ 575,000,000
Ratio of indebtedness to earnings before interest		3				4
Ratio of indebtedness to EBITDA					4.5				2.5
Ratio of EBITDA to interest expense, minimum		2
Ratio of current assets to current liabilities, minimum		1
Minimum percent of outstanding principal amount required for changes to credit agreement	66.67%
Discount rate relating to proved oil and gas reserves		10.00%
Long-term debt, gross, current		$ 541,000,000					$ 0
Interest rate at period end		5.44%
Remaining borrowing capacity		$ 32,900,000
Interest expense		27,300,000
Letters of credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 2,000,000
Second Lien Term Loan
Line of Credit Facility [Line Items]
Interest expense		$ 41,000,000
$300 Million Term Loan at 12% \| Second Lien Term Loan
Line of Credit Facility [Line Items]
Ratio of indebtedness to earnings before interest		3				4
Minimum required cash and cash equivalents to secured debt ratio		0.85
Stated interest rate										12.00%
Subsequent Event \| Credit Facility due 2019
Line of Credit Facility [Line Items]
Maximum borrowing capacity			$ 575,000,000
Subsequent Event \| $300 Million Term Loan at 12% \| Second Lien Term Loan
Line of Credit Facility [Line Items]
Minimum required cash and cash equivalents to secured debt ratio				1

Long-Term Debt - Second Lien Te

Long-Term Debt - Second Lien Term Loans (Details)	12 Months Ended
Long-Term Debt - Second Lien Term Loans (Details)	Dec. 31, 2018USD ($)	Jul. 01, 2020USD ($)	Sep. 20, 2018	Dec. 31, 2017USD ($)	Oct. 25, 2016USD ($)
Debt Instrument [Line Items]
Long-term debt, gross	$ 468,267,000			$ 1,369,645,000
Second Lien Term Loan
Debt Instrument [Line Items]
Interest expense	41,000,000
Second Lien Term Loan \| $300 Million Term Loan at 12%
Debt Instrument [Line Items]
Aggregate principal amount	400,000,000				$ 300,000,000
Upfront fee					2.00%
Stated interest rate					12.00%
Debt Instrument, Unused Borrowing Capacity, Amount	$ 61,400,000
Minimum required cash and cash equivalents to secured debt ratio	0.85
Ratio of indebtedness to earnings before interest	3		4
Ratio of secured debt to EBITDA	4.5
Scenario, Forecast \| Senior notes
Debt Instrument [Line Items]
Long-term debt, gross		$ 15,000,000

Long-Term Debt - Senior Notes (

Long-Term Debt - Senior Notes (Details)	Sep. 20, 2018USD ($)shares	Jun. 01, 2016USD ($)shares	May 13, 2014USD ($)	May 28, 2013USD ($)	Dec. 04, 2012USD ($)	Sep. 30, 2018USD ($)shares	Dec. 31, 2018USD ($)d$ / sharesshares	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Long-term Debt							$ 1,289,569,000	$ 1,346,769,000
Gain on extinguishment of debt							66,066,000	0	$ 150,802,000
Long-term debt, gross							$ 468,267,000	1,369,645,000
Common stock, shares outstanding (in shares) \| shares							109,442,278
December 1, 2018 through May 31, 2019
Debt Instrument [Line Items]
Conversion price per share of common stock \| $ / shares							$ 64.22
June 1, 2019 through September 19, 2019
Debt Instrument [Line Items]
Conversion price per share of common stock \| $ / shares							$ 24.22
8% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Common stock, shares issued \| shares						105,020
Debt Conversion, Converted Instrument, Shares Issued \| shares							316,828
Common stock, shares outstanding (in shares) \| shares	105,020
6.625% Senior Notes due 2021
Debt Instrument [Line Items]
Debt Conversion, Converted Instrument, Shares Issued \| shares							2,000,000
8% Senior Notes due 2020
Debt Instrument [Line Items]
Debt Conversion, Converted Instrument, Shares Issued \| shares							1,000,000
Senior notes
Debt Instrument [Line Items]
Gain on extinguishment of debt	$ 10,700,000
Senior notes \| 8% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Aggregate principal amount							$ 1,901,000
Stated interest rate							8.00%
Redemption price percentage							100.00%
Long-term debt, gross							$ 128,103,000	0
Fair value of liability							101,000,000
Unamortized debt discount							$ 29,000,000
Conversion ratio							166.6667
Conversion price per share of common stock \| $ / shares							$ 6
Threshold trading days \| d							20
Threshold consecutive trading days \| d							30
Senior notes \| 8% Convertible Senior Notes due 2023 \| Change in Control
Debt Instrument [Line Items]
Redemption price percentage							101.00%
Senior notes \| 6.625% Senior Notes due 2021
Debt Instrument [Line Items]
Aggregate principal amount	109,000,000		$ 300,000,000	$ 250,000,000
Stated interest rate			6.625%				6.625%
Debt instrument, issued, percent of par			99.00%	98.405%
Long-term debt, gross							$ 131,279,000	432,656,000
Face amount of repurchased debt								187,100,000	117,300,000
Face amount of converted debt		$ 15,000,000
Interest expense							$ 34,600,000
Senior notes \| 6.625% Senior Notes due 2021 \| Change in Control
Debt Instrument [Line Items]
Redemption price percentage							101.00%
Senior notes \| 8% Senior Notes due 2020
Debt Instrument [Line Items]
Aggregate principal amount					$ 300,000,000	$ 21,004,000	$ 3,100,000
Stated interest rate							8.00%
Debt instrument, issued, percent of par					97.848%
Long-term Debt							$ 5,300,000
Gain on extinguishment of debt						$ 1,400,000
Long-term debt, gross							208,885,000	$ 232,989,000
Face amount of repurchased debt									$ 52,000,000
Interest expense							$ 34,600,000
Senior notes \| 8% Senior Notes due 2020 \| Change in Control
Debt Instrument [Line Items]
Redemption price percentage							101.00%
Limited Partner \| Common Equity
Debt Instrument [Line Items]
Units issued in exchange for retirement of debt (in shares) \| shares		2,719,124
Legacy Reserves Finance Corporation
Debt Instrument [Line Items]
Ownership interest			100.00%	100.00%	100.00%		100.00%
Senior notes \| 8% Notes Due 2020, Tranche 1
Debt Instrument [Line Items]
Extinguishment of debt	21,004,000
Senior notes \| 8% Notes Due 2023, Tranche 1
Debt Instrument [Line Items]
Aggregate principal amount	21,004,000
Senior notes \| 6.625% Percent Notes Due 2021, Tranche 2
Debt Instrument [Line Items]
Extinguishment of debt	109,000,000
Senior notes \| 8% Notes Due 2023, Tranche 2
Debt Instrument [Line Items]
Aggregate principal amount	$ 109,000,000

Impact of ASC 606 Adoption (Det

Impact of ASC 606 Adoption (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	$ 554,861	$ 436,301	$ 314,357
Oil and natural gas production	200,285	183,219	179,333
Net income	43,833	(53,897)	(55,820)
Partners' capital	271,687	(271,687)
Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	547,611
Net income	43,833
Partners' capital	271,687
Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	(7,250)
Net income	0
Partners' capital	0
Oil Sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	375,444	239,448	152,507
Oil Sales \| Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	375,244
Oil Sales \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	(200)
Natural Gas Liquids Sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	27,750	24,796	15,406
Natural Gas Liquids Sales \| Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	27,232
Natural Gas Liquids Sales \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	(518)
Natural Gas Sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	151,667	$ 172,057	$ 146,444
Natural Gas Sales \| Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	145,135
Natural Gas Sales \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	(6,532)
Oil and Gas
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Oil and natural gas production	200,285
Oil and Gas \| Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Oil and natural gas production	193,035
Oil and Gas \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Oil and natural gas production	$ (7,250)

Revenues from Contracts with _3

Revenues from Contracts with Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenues	$ 554,861	$ 436,301	$ 314,357
Oil Sales
Disaggregation of Revenue [Line Items]
Revenues	375,444	239,448	152,507
Natural Gas Liquids Sales
Disaggregation of Revenue [Line Items]
Revenues	27,750	24,796	15,406
Natural Gas Sales
Disaggregation of Revenue [Line Items]
Revenues	$ 151,667	$ 172,057	$ 146,444

Asset Acquisitions and Dispos_2

Asset Acquisitions and Dispositions (Details) - USD ($) $ in Thousands	Aug. 01, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Proceeds from sale of assets		$ 54,968	$ 11,099	$ 97,416
Loss (gain) on disposal of assets		$ (23,803)	$ 1,606	$ (50,095)
Jupiter JV, LP
Business Acquisition [Line Items]
Payments to acquire business	$ 141,000

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	12 Months Ended
Related Party Transactions (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Water Transfer Services \| Blue Quail Energy Services, LLC \| Board of Directors Chairman and Director
Related Party Transaction [Line Items]
Related party transaction amount	$ 169,949	$ 9,758	$ 98,297

Commitments and Contingencies (

Commitments and Contingencies (Details) - Officer	12 Months Ended
Commitments and Contingencies (Details) - Officer	Dec. 31, 2018
Loss Contingencies [Line Items]
Employment agreements with officers, severance pay consideration period, minimum	12 months
Employment agreements with officers, severance pay consideration period, maximum	36 months

Business and Credit Concentra_2

Business and Credit Concentrations (Details) - USD ($)	12 Months Ended
Business and Credit Concentrations (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Risks and Uncertainties [Abstract]
Bad debt expense	$ 0	$ 0	$ 0
Fair value of derivative transactions	$ 67,200,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Recurring - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative assets (liabilities), net	$ 69,247	$ 6,488
Quoted Prices in Active Markets for Identical Assets (Level 1)
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative assets (liabilities), net	0	0
Significant Other Observable Inputs (Level 2)
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative assets (liabilities), net	69,247	11,576
Significant Unobservable Inputs (Level 3)
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative assets (liabilities), net	0	(5,088)
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3
Beginning balance	(5,088)	8	$ (4,493)
Total gains (losses)	30,571	(5,073)	253
Settlements	(22,379)	(23)	4,248
Transfers	(3,104)	0	0
Ending balance	0	(5,088)	8
Gains included in earnings relating to derivatives	30,571	(5,073)	253
Significant Unobservable Inputs (Level 3) \| Derivative assets
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3
Total gains (losses)	0	(5,088)	68
Gains included in earnings relating to derivatives	0	(5,088)	$ 68
Derivatives Asset Current \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	69,288	19,792
Gross Amounts Offset in the Consolidated Balance Sheets	(4,670)	(7,204)
Derivative assets	64,618	12,588
Derivatives Asset Current \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	2,044	837
Gross Amounts Offset in the Consolidated Balance Sheets	0	(1)
Derivative assets	2,044	836
Derivatives Asset Current \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Asset Current \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Asset Current \| Significant Other Observable Inputs (Level 2) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	69,288	19,792
Derivatives Asset Current \| Significant Other Observable Inputs (Level 2) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	2,044	837
Derivatives Asset Current \| Significant Unobservable Inputs (Level 3) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Asset Current \| Significant Unobservable Inputs (Level 3) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Asset Noncurrent \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	3,473	14,278
Gross Amounts Offset in the Consolidated Balance Sheets	(338)	(1,460)
Derivative assets	3,135	12,818
Derivatives Asset Noncurrent \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	1,281
Gross Amounts Offset in the Consolidated Balance Sheets	0
Derivative assets	0	1,281
Derivatives Asset Noncurrent \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Asset Noncurrent \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Asset Noncurrent \| Significant Other Observable Inputs (Level 2) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	3,473	14,278
Derivatives Asset Noncurrent \| Significant Other Observable Inputs (Level 2) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	1,281
Derivatives Asset Noncurrent \| Significant Unobservable Inputs (Level 3) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Asset Noncurrent \| Significant Unobservable Inputs (Level 3) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Assets	0	0
Derivatives Liability Current \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	(4,670)	(25,218)
Gross Amounts Offset in the Consolidated Balance Sheets	4,670	7,204
Derivative liability	0	(18,014)
Derivatives Liability Current \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		(1)
Gross Amounts Offset in the Consolidated Balance Sheets		1
Derivative liability		0
Derivatives Liability Current \| LTIP liability
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		(1,947)
Derivative liability		(1,947)
Derivatives Liability Current \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	0	0
Derivatives Liability Current \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		0
Derivatives Liability Current \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| LTIP liability
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		0
Derivatives Liability Current \| Significant Other Observable Inputs (Level 2) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	(4,670)	(21,027)
Derivatives Liability Current \| Significant Other Observable Inputs (Level 2) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		(1)
Derivatives Liability Current \| Significant Other Observable Inputs (Level 2) \| LTIP liability
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		(1,947)
Derivatives Liability Current \| Significant Unobservable Inputs (Level 3) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	0	(4,191)
Derivatives Liability Current \| Significant Unobservable Inputs (Level 3) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		0
Derivatives Liability Current \| Significant Unobservable Inputs (Level 3) \| LTIP liability
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		0
Derivatives Liability Noncurrent \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	(888)	(2,534)
Gross Amounts Offset in the Consolidated Balance Sheets	338	1,460
Derivative liability	(550)	(1,074)
Derivatives Liability Noncurrent \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		0
Derivative liability		0
Derivatives Liability Noncurrent \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	0	0
Derivatives Liability Noncurrent \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Interest rate derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities		0
Derivatives Liability Noncurrent \| Significant Other Observable Inputs (Level 2) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	(888)	(1,637)
Derivatives Liability Noncurrent \| Significant Unobservable Inputs (Level 3) \| Commodity derivatives
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Gross Amounts of Recognized Liabilities	$ 0	$ (897)

Fair Value Measurements Narrati

Fair Value Measurements Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of oil and gas properties	$ 9,300
Oil and natural gas properties, fair value	1,314,313	$ 1,353,356
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of oil and gas properties	43,946	31,850
Nonrecurring \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of oil and gas properties	58,700	37,300
Oil and natural gas properties, net cost basis	102,600	69,100
Oil and natural gas properties, fair value	$ 43,946	$ 31,800

Derivative Financial Instrume_3

Derivative Financial Instruments - Commodity Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Total gain (loss) on derivatives	$ 49,099	$ 19,711	$ (40,679)
Derivative cash settlements paid (received)	11,715	(24,156)	(64,505)
Ending fair value of derivatives	67,200
Not designated as hedging instrument \| Commodity derivatives
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Beginning fair value of derivatives	6,318	12,698	118,427
Ending fair value of derivatives	67,205	6,318	12,698
Not designated as hedging instrument \| Commodity derivatives \| Oil
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Total gain (loss) on derivatives	54,380	(15,325)	(9,410)
Derivative cash settlements paid (received)	16,845	(11,840)	(37,464)
Not designated as hedging instrument \| Commodity derivatives \| Natural gas
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Total gain (loss) on derivatives	(5,208)	33,101	(31,814)
Derivative cash settlements paid (received)	$ (5,130)	$ (12,316)	$ (27,041)

Derivative Financial Instrume_4

Derivative Financial Instruments - Schedule of Derivatives, Gain (Loss) on Derivative Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Cash settlements paid	$ 11,715	$ (24,156)	$ (64,505)
Ending fair value of derivatives	67,200
Interest rate derivatives \| Not designated as hedging instrument
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Beginning fair value of derivatives	2,117	183	(362)
Total gain (loss) loss on interest rate swaps	1,213	1,168	(2,108)
Cash settlements paid	(1,286)	766	2,653
Ending fair value of derivatives	$ 2,044	$ 2,117	$ 183

Derivative Financial Instrume_5

Derivative Financial Instruments - Schedule of Derivatives, Notional Amounts Outstanding (Details) bbl in Thousands, MMBTU in Thousands, $ in Thousands	Dec. 31, 2018USD ($)MMBTUbbl$ / MMBTU$ / bbl
NYMEX WTI Swaps \| Crude Oil \| 2019
Derivative [Line Items]
Volumes \| bbl	3,285
Average price per bbl ($ per bbl)	(61.33)
NYMEX WTI Swaps \| Crude Oil \| 2019 \| Minimum
Derivative [Line Items]
Price range per bbl ($ per bbl)	(57.15)
NYMEX WTI Swaps \| Crude Oil \| 2019 \| Maximum
Derivative [Line Items]
Price range per bbl ($ per bbl)	(67.65)
Midland-to-Cushing Differential Swaps \| Crude Oil \| 2019
Derivative [Line Items]
Volumes \| bbl	2,193
Average price per bbl ($ per bbl)	(3.62)
Midland-to-Cushing Differential Swaps \| Crude Oil \| 2019 \| Minimum
Derivative [Line Items]
Price range per bbl ($ per bbl)	(5.60)
Midland-to-Cushing Differential Swaps \| Crude Oil \| 2019 \| Maximum
Derivative [Line Items]
Price range per bbl ($ per bbl)	(1.15)
Midland-to-Cushing Crude Oil Enhanced Swap \| Crude Oil \| 2019
Derivative [Line Items]
Volumes \| bbl	1,460
Average price per bbl ($ per bbl)	(2.91)
Midland-to-Cushing Crude Oil Enhanced Swap \| Crude Oil \| 2019 \| Short
Derivative [Line Items]
Average short call price	70
NYMEX Henry Hub Natural Gas Swaps \| Natural gas \| 2019
Derivative [Line Items]
Volumes \| MMBTU	37,175
Average price per bbl ($ per bbl) \| $ / MMBTU	(3.36)
NYMEX Henry Hub Natural Gas Swaps \| Natural gas \| 2019 \| Minimum
Derivative [Line Items]
Price range per bbl ($ per bbl) \| $ / MMBTU	(3.05)
NYMEX Henry Hub Natural Gas Swaps \| Natural gas \| 2019 \| Maximum
Derivative [Line Items]
Price range per bbl ($ per bbl) \| $ / MMBTU	(4.40)
NYMEX Henry Hub Natural Gas Differential Swaps \| Natural gas \| 2019
Derivative [Line Items]
Volumes \| MMBTU	3,600
Average price per bbl ($ per bbl) \| $ / MMBTU	(0.47)
NYMEX Henry Hub Natural Gas Differential Swaps \| Natural gas \| 2019 \| Minimum
Derivative [Line Items]
Price range per bbl ($ per bbl) \| $ / MMBTU	(0.46)
NYMEX Henry Hub Natural Gas Differential Swaps \| Natural gas \| 2019 \| Maximum
Derivative [Line Items]
Price range per bbl ($ per bbl) \| $ / MMBTU	(0.49)
Interest Rate Swap Due Sept 2019
Derivative [Line Items]
Estimated fair market value, net \| $	$ 2,044
Not designated as hedging instrument \| Interest Rate Swap Due Sept 2019
Derivative [Line Items]
Notional amount, assets \| $	$ 235,000
Weighted average fixed rate	1.363%
Estimated fair market value, assets \| $	$ 2,044

Sales to Major Customers (Detai

Sales to Major Customers (Details) - Sales Revenue, Goods, Net - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Plains Marketing, LP
Concentration Risk [Line Items]
Percentage of consolidated oil and natural gas revenue	20.00%	10.00%	6.00%
Rio Energy International Inc
Concentration Risk [Line Items]
Percentage of consolidated oil and natural gas revenue	13.00%	9.00%	3.00%

Asset Retirement Obligation (De

Asset Retirement Obligation (Details) - USD ($)	12 Months Ended
Asset Retirement Obligation (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in the ARO
Asset retirement obligation — beginning of period	$ 274,686,000	$ 272,148,000	$ 286,405,000
Liabilities incurred with properties acquired	226,000	62,000	24,000
Liabilities incurred with properties drilled	65,000	39,000	1,000
Liabilities settled during the period	(2,258,000)	(1,891,000)	(2,351,000)
Liabilities associated with properties sold	(27,673,000)	(8,464,000)	(24,605,000)
Current period accretion	12,568,000	12,792,000	12,674,000
Current period revisions to previous estimates	(4,880,000)	0	0
Asset retirement obligation — end of period	$ 252,734,000	$ 274,686,000	$ 272,148,000

Asset Retirement Obligation Nar

Asset Retirement Obligation Narrative (Details) - USD ($)	12 Months Ended
Asset Retirement Obligation Narrative (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation [Abstract]
Current period revisions to previous estimates	$ (4,880,000)	$ 0	$ 0

Stockholders' Deficit_Partner_3

Stockholders' Deficit/Partners' Deficit - Income (loss) per unit (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Income/(loss)	$ 43,833	$ (53,897)	$ (55,820)
Income/(loss) attributable to shareholders	$ 43,833	$ (53,897)	$ (55,820)
Weighted average number of units outstanding (in shares)	105,087,000	100,049,000	98,249,000
Effect of dilutive securities:
Restricted and phantom units (in shares)	0	0	0
Weighted average unit and potential units outstanding (in shares)	105,087,000	100,049,000	98,249,000
Basic and diluted loss per unit (in dollars per share)	$ 0.42	$ (0.54)	$ (0.57)
Restricted stock units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive restricted units excluded from computation of EPS (in shares)	7,302,809	241,373	484,447
Phantom share units (PSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive restricted units excluded from computation of EPS (in shares)		1,389,773	1,212,692
Convertible debt securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive restricted units excluded from computation of EPS (in shares)	21,356,510

Stock-Based Compensation - LTIP

Stock-Based Compensation - LTIP and Unit Appreciation Rights (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Mar. 15, 2006
Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options granted (in shares)	7,523,720
Share-based compensation expense	$ 4,100,000
Phantom share units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 22,900,000	$ 4,600,000	$ 3,700,000
Unit appreciation rights (UARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options granted (in shares)	0	0
Share-based compensation expense	$ (169,024)	$ (37,240)	$ 223,569
Unit appreciation rights (UARs) \| Ratable vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options granted (in shares)			204,500
Award vesting period			3 years
Unit appreciation rights (UARs) \| Cliff vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options granted (in shares)			96,520
Award vesting period			3 years
LTIP liability
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units authorized for issuance (in shares)				5,000,000
Units issued as compensation (in shares)	3,459,197
LTIP liability \| Unit option awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	266,014
LTIP liability \| Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	988,207
LTIP liability \| Phantom share units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	1,424,114
LTIP liability \| Unrestricted units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	780,862

Stock-Based Compensation - UAR

Stock-Based Compensation - UAR Activity (Details) - Unit appreciation rights (UARs) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Restricted Stock Units
Outstanding (in shares)	722,021	884,546	936,116
Granted (in shares)	0	0
Expired (in shares)	(90,844)	(147,024)	(21,067)
Forfeited (in shares)	(631,177)	(15,501)	(30,503)
Outstanding (in shares)	0	722,021	884,546
Options and UARs exercisable (in shares)	0	592,522	570,369
Weighted-Average Exercise Price (in dollars per share)
Outstanding (in dollars per share)	$ 20.13	$ 20.75	$ 20.61
Granted (in dollars per share)			16.07
Expired (in dollars per share)	4.69	24.50
Forfeited (in dollars per share)	22.35	13.91	19.80
Outstanding (in dollars per share)	0	20.13	20.75
Options and UARs exercisable (in dollars per share)	$ 0	$ 23.23	$ 24.38
Weighted-Average Remaining Contractual Term
Outstanding	0 years	3 years 3 months 13 days	3 years 8 months 3 days
Options and UARs exercisable	0 years	2 years 11 months 27 days	2 years 9 months 7 days
Aggregate Intrinsic Value
Outstanding	$ 0	$ 0	$ 0
Options and UARs exercisable	$ 0	$ 0	$ 0

Stock-Based Compensation - Stat

Stock-Based Compensation - Status of the Partnership's non-vested UARs (Details) - Unit appreciation rights (UARs)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Number of Units (in shares)
Non-vested, beginning balance (in units) \| shares	129,499
Vested (in units) \| shares	(124,832)
Forfeited (in units) \| shares	(4,667)
Non-vested, ending balance (in units) \| shares	0
Weighted- Average Exercise Price (in dollars per share)
Non-vested, beginning balance (in dollars per unit) \| $ / shares	$ 5.97
Vested (in dollars per unit) \| $ / shares	5.99
Forfeited (in dollars per unit) \| $ / shares	5.25
Non-vested, ending balance (in dollars per unit) \| $ / shares	$ 0

Stock-Based Compensation - Phan

Stock-Based Compensation - Phantom, Board and Restricted Units (Details) $ / shares in Units, $ in Millions	May 15, 2018director$ / sharesshares	May 16, 2017director$ / sharesshares	May 10, 2016$ / sharesshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Oct. 26, 2018director$ / shares	Sep. 25, 2018director$ / shares
Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of each unit at issuance (in dollars per share) \| $ / shares	$ 8.69	$ 2.04
Individuals eligible for plan \| director							1	4
Phantom share units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense \| $				$ 22.9	$ 4.6	$ 3.7
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense \| $				0.8	$ 1.5	$ 2.7
Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense \| $				$ 4.1
Unrestricted units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of each unit at issuance (in dollars per share) \| $ / shares			$ 2.59
Unrestricted units \| Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) \| shares	12,019	47,847	39,526
Value of each unit at issuance (in dollars per share) \| $ / shares							$ 5.02	$ 4.97
Individuals eligible for plan \| director	4	6
Unrestricted units \| Director 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares) \| shares	6,010

Stock-Based Compensation - Ince

Stock-Based Compensation - Incentive Plan, Restricted Stock Units, and Board Shares (Details) $ / shares in Units, $ in Millions	Oct. 26, 2018director$ / sharesshares	Sep. 25, 2018director$ / sharesshares	Dec. 31, 2018USD ($)shares	Sep. 19, 2018shares	May 15, 2018director$ / shares	May 16, 2017director$ / shares	May 10, 2016$ / shares
Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			7,523,720
Share-based compensation expense \| $			$ 4.1
Unrecognized compensation costs \| $			$ 31.5
Unrecognized compensation costs, period of recognition			3 years 2 months
Unrestricted units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of each unit at issuance (in dollars per share) \| $ / shares							$ 2.59
Omnibus Incentive Plan 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units authorized for issuance (in shares)				10,500,000
Percentage increase in plan for shares issued				0.1
Grants of awards, net of forfeitures			7,335,379
Grants of options, net of forfeitures			32,570
Omnibus Incentive Plan 2018 \| Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			7,302,809
Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants of options, net of forfeitures	12,450	5,030
Individuals eligible for plan \| director	1	4
Value of each unit at issuance (in dollars per share) \| $ / shares					$ 8.69	$ 2.04
Non-employee directors \| Unrestricted units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Individuals eligible for plan \| director					4	6
Value of each unit at issuance (in dollars per share) \| $ / shares	$ 5.02	$ 4.97

Stock-Based Compensation - RSU

Stock-Based Compensation - RSU Activity (Details) - Restricted stock units (RSUs)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Number of Restricted Stock Units
Outstanding (in shares)	0
Granted (in shares)	7,523,720
Expired (in shares)	0
Forfeited (in shares)	(220,911)
Outstanding (in shares)	7,302,809
Weighted-Average Exercise Price (in dollars per share)
Outstanding (in dollars per share) \| $ / shares	$ 0
Grants (in dollars per share) \| $ / shares	4.89
Forfeited (in dollars per share) \| $ / shares	5.14
Outstanding (in dollars per share) \| $ / shares	$ 4.88

Income Taxes Narrative (Details

Income Taxes Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	21.00%	35.00%	35.00%
US federal income tax rate	6.30%	(2.70%)	(2.30%)
Income (loss) before income taxes	$ 46,801	$ (52,499)	$ (54,591)
Net operating loss carryforward	57,000
Net interest expense carryover	29,000
Operating loss carryforward, subject to expiration	$ 21,000

Income Taxes Schedule of Income

Income Taxes Schedule of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 140	$ 1,911	$ 1,183
State	(147)	(52)	(193)
Current income tax provision	(7)	1,859	990
Deferred:
Federal	1,270	(464)	(782)
State	1,705	3	1,021
Deferred income tax provision	2,975	(461)	239
Total continuing operations	$ 2,968	$ 1,398	$ 1,229

Income Taxes Schedule of Inco_2

Income Taxes Schedule of Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Tax at federal statutory rate	21.00%	35.00%	35.00%
Partnership loss not subject to federal tax	16.60%	(36.10%)	(35.70%)
Federal rate change	0.00%	(1.60%)	0.00%
2023 Convertible Notes issuance	7.40%	0.00%	0.00%
Valuation allowance adjustment	(44.10%)	0.00%	0.00%
Texas margins tax	6.10%	(1.60%)	(2.00%)
Other	(0.70%)	1.60%	0.40%
Effective tax rate	6.30%	(2.70%)	(2.30%)

Income Taxes Schedule of Deferr

Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Oil and natural gas properties	$ 91,948	$ 1,840
Net operating losses	12,961	0
Interest expense	6,668	0
Other	0	1,176
Total deferred tax assets	111,577	3,016
Hedging activities	(15,934)	(32)
Other	(1,585)	(11)
Total deferred tax liabilities	(17,519)	(43)
Valuation allowance	(94,058)	0
Net deferred tax assets	$ 0	$ 2,973

Guarantors (Details)

Guarantors (Details) - Senior notes	11 Months Ended
Guarantors (Details) - Senior notes	May 08, 2014offering	Dec. 31, 2018	Sep. 20, 2018USD ($)	May 13, 2014USD ($)	May 28, 2013USD ($)
6.625% Senior Notes due 2021
Debt Instrument [Line Items]
Number of private offerings \| offering	2
Aggregate principal amount \| $			$ 109,000,000	$ 300,000,000	$ 250,000,000
2020 and 2021 Senior Notes
Debt Instrument [Line Items]
Percent of guarantee by subsidiaries owned		100.00%

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details) - Credit Facility due 2019 - USD ($)	May 31, 2019	Mar. 21, 2019	Apr. 01, 2019	Apr. 01, 2014
Subsequent Event [Line Items]
Maximum borrowing capacity				$ 1,500,000,000
Subsequent Event
Subsequent Event [Line Items]
Maximum borrowing capacity		$ 575,000,000
Twelfth Amendment Credit Agreement \| Subsequent Event
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)		2.25%
Commitment fee percentage	0.15%	0.35%
Maximum borrowing capacity		$ 570,000,000
Loan prepayment amount			$ 15,000,000