Black Stone Minerals (BSM) 10-Q 4 Aug 20 2020 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	001-37362
Entity Registrant Name	Black Stone Minerals, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-1846692
Entity Address, Address Line One	1001 Fannin Street, Suite 2020
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	(713)
Local Phone Number	445-3200
Title of 12(b) Security	Common Units Representing Limited Partner Interests
Trading Symbol	BSM
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller reporting company	false
Emerging growth company	false
Entity shell company	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001621434
Current Fiscal Year End Date	--12-31
Common Units
Entity Information [Line Items]
Entity Partnership Units Outstanding (in shares)		206,737,644
Preferred Units
Entity Information [Line Items]
Entity Partnership Units Outstanding (in shares)		14,711,219

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
CURRENT ASSETS
Cash and cash equivalents	$ 1,600	$ 8,119
Accounts receivable	45,480	78,214
Commodity derivative assets	45,522	14,790
Assets held for sale	126,491	0
Prepaid expenses and other current assets	2,329	1,168
TOTAL CURRENT ASSETS	221,422	102,291
PROPERTY AND EQUIPMENT
Oil and natural gas properties, at cost, using the successful efforts method of accounting, includes unproved properties of $946,232 and $1,073,447 at June 30, 2020 and December 31, 2019, respectively	3,156,657	3,302,340
Accumulated depreciation, depletion, amortization, and impairment	(1,947,455)	(1,870,412)
Oil and natural gas properties, net	1,209,202	1,431,928
Other property and equipment, net of accumulated depreciation of $11,963 and $11,622 at June 30, 2020 and December 31, 2019, respectively	1,969	2,300
NET PROPERTY AND EQUIPMENT	1,211,171	1,434,228
DEFERRED CHARGES AND OTHER LONG-TERM ASSETS	6,245	8,689
TOTAL ASSETS	1,438,838	1,545,208
CURRENT LIABILITIES
Accounts payable	2,870	5,309
Accrued liabilities	10,337	22,702
Commodity derivative liabilities	311	159
Other current liabilities	1,634	1,633
TOTAL CURRENT LIABILITIES	15,152	29,803
LONG–TERM LIABILITIES
Credit facility	323,000	394,000
Accrued incentive compensation	580	2,110
Commodity derivative liabilities	4,738	18
Asset retirement obligations	16,717	15,653
Other long-term liabilities	4,609	6,820
TOTAL LIABILITIES	364,796	448,404
COMMITMENTS AND CONTINGENCIES (Note 7)
EQUITY
Partners' equity – general partner interest	0	0
TOTAL EQUITY	775,681	798,443
TOTAL LIABILITIES, MEZZANINE EQUITY, AND EQUITY	1,438,838	1,545,208
Series B Cumulative Convertible Preferred Units
MEZZANINE EQUITY
Partners' equity – convertible preferred units	298,361	298,361
Common Units
EQUITY
Partners' equity - units	$ 775,681	$ 798,443

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Unproved properties	$ 946,232	$ 1,073,447
Accumulated depreciation	$ 11,963	$ 11,622
Series B Cumulative Convertible Preferred Units
Partners' equity, preferred units, outstanding (in shares)	14,711	14,711
Common Units
Partners' equity - units, outstanding (in shares)	206,709	205,960

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
REVENUE
Revenue from contracts with customers	$ 57,703,000	$ 134,431,000	$ 150,746,000	$ 259,420,000
Gain (loss) on commodity derivative instruments	(19,174,000)	29,187,000	70,837,000	(11,996,000)
TOTAL REVENUE	38,529,000	163,618,000	221,583,000	247,424,000
OPERATING (INCOME) EXPENSE
Lease operating expense	3,293,000	3,849,000	7,120,000	9,141,000
Production costs and ad valorem taxes	9,555,000	14,450,000	21,931,000	29,042,000
Exploration expense	23,000	304,000	24,000	308,000
Depreciation, depletion, and amortization	19,193,000	29,725,000	42,375,000	57,558,000
Impairment of oil and natural gas properties	0	0	51,031,000	0
General and administrative	11,501,000	14,347,000	23,357,000	35,561,000
Accretion of asset retirement obligations	278,000	277,000	550,000	554,000
TOTAL OPERATING EXPENSE	43,843,000	62,952,000	146,388,000	132,164,000
INCOME (LOSS) FROM OPERATIONS	(5,314,000)	100,666,000	75,195,000	115,260,000
OTHER INCOME (EXPENSE)
Interest and investment income	3,000	47,000	34,000	93,000
Interest expense	(2,964,000)	(5,652,000)	(7,391,000)	(11,177,000)
Other income (expense)	(96,000)	26,000	(97,000)	(72,000)
TOTAL OTHER EXPENSE	(3,057,000)	(5,579,000)	(7,454,000)	(11,156,000)
NET INCOME (LOSS)	(8,371,000)	95,087,000	67,741,000	104,104,000
Distributions on Series B cumulative convertible preferred units	5,250,000	5,250,000	10,500,000	10,500,000
Distributions on Series B cumulative convertible preferred units	(5,250,000)	(5,250,000)	(10,500,000)	(10,500,000)
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND COMMON AND SUBORDINATED UNITS	(13,621,000)	89,837,000	57,241,000	93,604,000
ALLOCATION OF NET INCOME (LOSS):
General partner interest	0	0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND COMMON AND SUBORDINATED UNITS	(13,621,000)	89,837,000	57,241,000	93,604,000
Common Units
ALLOCATION OF NET INCOME (LOSS):
Allocation of net income (loss)	$ (13,621,000)	$ 67,718,000	$ 57,241,000	$ 69,611,000
NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER COMMON AND SUBORDINATED UNIT:
Per unit (basic) (in dollars per share)	$ (0.07)	$ 0.45	$ 0.28	$ 0.54
Weighted average units outstanding (basic) (in shares)	206,707	150,101	206,669	129,873
Per unit (diluted) (in dollars per share)	$ (0.07)	$ 0.44	$ 0.28	$ 0.54
Weighted average units outstanding (diluted) (in shares)	206,707	165,070	206,669	129,873
Subordinated units
ALLOCATION OF NET INCOME (LOSS):
Allocation of net income (loss)	$ 0	$ 22,119,000	$ 0	$ 23,993,000
NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER COMMON AND SUBORDINATED UNIT:
Per unit (basic) (in dollars per share)	$ 0	$ 0.39	$ 0	$ 0.32
Weighted average units outstanding (basic) (in shares)	0	56,104	0	76,105
Per unit (diluted) (in dollars per share)	$ 0	$ 0.39	$ 0	$ 0.32
Weighted average units outstanding (diluted) (in shares)	0	56,104	0	76,105
Oil and condensate sales
REVENUE
Revenue from contracts with customers	$ 25,417,000	$ 74,072,000	$ 77,510,000	$ 131,776,000
Natural gas and natural gas liquids sales
REVENUE
Revenue from contracts with customers	30,311,000	53,642,000	66,953,000	115,282,000
Lease bonus and other income
REVENUE
Revenue from contracts with customers	$ 1,975,000	$ 6,717,000	$ 6,283,000	$ 12,362,000

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Units	Subordinated units	Partners' equity — common units	Partners' equity — subordinated units	Series B cumulative convertible preferred units on an as-converted basis	Series B cumulative convertible preferred units on an as-converted basisPartners' equity — common units
Beginning balance (in shares) at Dec. 31, 2018		108,363	96,329
Beginning balance at Dec. 31, 2018	$ 904,263			$ 714,823	$ 189,440
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases of common and subordinated units (in shares)		(588)
Repurchases of common units	(10,110)			(10,110)
Issuance of common units, net of offering costs	(43)			(43)
Issuance of common units for property acquisitions (in shares)		57
Issuance of common units for property acquisitions	943			943
Restricted units granted, net of forfeitures (in shares)		1,545
Equity–based compensation	13,669			13,669
Distributions	(75,917)			(40,275)	(35,642)
Charges to partners' equity for accrued distribution equivalent rights	(1,044)			(1,044)
Distributions on preferred units						$ (5,250)	$ (5,250)
Net income (loss)	9,017			7,155	1,862
Ending balance (in shares) at Mar. 31, 2019		109,377	96,329
Ending balance at Mar. 31, 2019	835,528			679,868	155,660
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of subordinated units (in shares)		96,329	(96,329)
Conversion of subordinated units	0			142,149	(142,149)
Repurchases of common and subordinated units (in shares)		(377)
Repurchases of common units	(6,164)			(6,164)
Restricted units granted, net of forfeitures (in shares)		627
Equity–based compensation	3,332			3,332
Distributions	(76,113)			(40,471)	(35,642)
Charges to partners' equity for accrued distribution equivalent rights	(766)			(766)
Distributions on preferred units						(5,250)	(5,250)
Net income (loss)	95,087			72,956	22,131
Ending balance (in shares) at Jun. 30, 2019		205,956	0
Ending balance at Jun. 30, 2019	845,654			845,654	$ 0
Beginning balance (in shares) at Dec. 31, 2019		205,960
Beginning balance at Dec. 31, 2019	798,443			798,443
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases of common and subordinated units (in shares)		(503)
Repurchases of common units	(5,029)			(5,029)
Restricted units granted, net of forfeitures (in shares)		1,238
Equity–based compensation	1,159			1,159
Distributions	(61,641)			(61,641)
Charges to partners' equity for accrued distribution equivalent rights	(68)			(68)
Distributions on preferred units						(5,250)	(5,250)
Net income (loss)	76,112			76,112
Ending balance (in shares) at Mar. 31, 2020		206,695
Ending balance at Mar. 31, 2020	803,726			803,726
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases of common and subordinated units (in shares)		0
Repurchases of common units	(6)			(6)
Restricted units granted, net of forfeitures (in shares)		14
Equity–based compensation	2,292			2,292
Distributions	(16,679)			(16,679)
Charges to partners' equity for accrued distribution equivalent rights	(31)			(31)
Distributions on preferred units						$ (5,250)	$ (5,250)
Net income (loss)	(8,371)			(8,371)
Ending balance (in shares) at Jun. 30, 2020		206,709
Ending balance at Jun. 30, 2020	$ 775,681			$ 775,681

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 67,741,000	$ 104,104,000
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion, and amortization	42,375,000	57,558,000
Impairment of oil and natural gas properties	51,031,000	0
Accretion of asset retirement obligations	550,000	554,000
Amortization of deferred charges	519,000	516,000
(Gain) loss on commodity derivative instruments	(70,837,000)	11,996,000
Net cash (paid) received on settlement of commodity derivative instruments	45,506,000	4,674,000
Equity-based compensation	(420,000)	13,039,000
Exploratory dry hole expense	0	3,000
Changes in operating assets and liabilities:
Accounts receivable	33,544,000	17,212,000
Prepaid expenses and other current assets	(1,163,000)	(976,000)
Accounts payable, accrued liabilities, and other	(10,790,000)	(7,405,000)
Settlement of asset retirement obligations	(87,000)	(299,000)
NET CASH PROVIDED BY OPERATING ACTIVITIES	157,969,000	200,976,000
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisitions of oil and natural gas properties	(28,000)	(40,676,000)
Additions to oil and natural gas properties	(4,146,000)	(50,121,000)
Additions to oil and natural gas properties leasehold costs	(782,000)	(871,000)
Purchases of other property and equipment	(10,000)	(2,152,000)
Proceeds from the sale of oil and natural gas properties	1,266,000	320,000
Proceeds from farmouts of oil and natural gas properties	4,067,000	47,487,000
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	367,000	(46,013,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of common units, net of offering costs	0	(43,000)
Distribution equivalents paid	0	(2,982,000)
Borrowings under credit facility	89,000,000	172,500,000
Repayments under credit facility	(160,000,000)	(146,500,000)
NET CASH USED IN FINANCING ACTIVITIES	(164,855,000)	(156,471,000)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(6,519,000)	(1,508,000)
CASH AND CASH EQUIVALENTS – beginning of the period	8,119,000	5,414,000
CASH AND CASH EQUIVALENTS – end of the period	1,600,000	3,906,000
SUPPLEMENTAL DISCLOSURE
Interest paid	6,934,000	10,618,000
Common and Subordinated Units
CASH FLOWS FROM FINANCING ACTIVITIES
Distributions to unitholders	(78,320,000)	(152,030,000)
Repurchases of common units	(5,035,000)	(16,916,000)
Series B cumulative convertible preferred units on an as-converted basis | Preferred Units
CASH FLOWS FROM FINANCING ACTIVITIES
Distributions to unitholders	$ (10,500,000)	$ (10,500,000)

Business and Basis of Presentat

Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	NOTE 1 - BUSINESS AND BASIS OF PRESENTATION Description of the Business Black Stone Minerals, L.P. (“BSM” or the “Partnership”) is a publicly traded Delaware limited partnership that owns oil and natural gas mineral interests, which make up the vast majority of the asset base. The Partnership's assets also include nonparticipating royalty interests and overriding royalty interests. These interests, which are substantially non-cost-bearing, are collectively referred to as “mineral and royalty interests.” The Partnership’s mineral and royalty interests are located in 41 states in the continental United States, including all of the major onshore producing basins. The Partnership also owns non-operated working interests in certain oil and natural gas properties. The Partnership's common units trade on the New York Stock Exchange under the symbol "BSM." Basis of Presentation The accompanying unaudited interim consolidated financial statements of the Partnership have been prepared in accordance with generally accepted accounting principles ("GAAP") in the United States and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). These unaudited interim consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and, therefore, do not include all disclosures required for financial statements prepared in conformity with GAAP. Accordingly, the accompanying unaudited interim consolidated financial statements and related notes should be read in conjunction with the Partnership’s consolidated financial statements included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2019 ("2019 Annual Report on Form 10-K"). The unaudited interim consolidated financial statements include the consolidated results of the Partnership. The results of operations for the six months ended June 30, 2020 are not necessarily indicative of the results to be expected for the full year. In the opinion of management, all adjustments, which are of a normal and recurring nature, necessary for the fair presentation of the financial results for all periods presented have been reflected. All intercompany balances and transactions have been eliminated. The Partnership evaluates the significant terms of its investments to determine the method of accounting to be applied to each respective investment. Investments in which the Partnership has less than a 20% ownership interest and does not have control or exercise significant influence are accounted for using fair value or cost minus impairment if fair value is not readily determinable. Investments in which the Partnership exercises control are consolidated, and the noncontrolling interests of such investments, which are not attributable directly or indirectly to the Partnership, are presented as a separate component of net income (loss) and equity. The unaudited interim consolidated financial statements include undivided interests in oil and natural gas property rights. The Partnership accounts for its share of oil and natural gas property rights by reporting its proportionate share of assets, liabilities, revenues, costs, and cash flows within the relevant lines on the accompanying unaudited interim consolidated balance sheets, statements of operations, and statements of cash flows. Segment Reporting The Partnership operates in a single operating and reportable segment. Operating segments are defined as components of an enterprise for which separate financial information is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assess performance. The Partnership’s chief executive officer has been determined to be the chief operating decision maker and allocates resources and assesses performance based upon financial information at the consolidated level.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies Significant accounting policies are disclosed in the Partnership’s 2019 Annual Report on Form 10-K. There have been no changes in such policies or the application of such policies during the six months ended June 30, 2020. Accounts Receivable The following table presents information about the Partnership's accounts receivable: June 30, 2020 December 31, 2019 (in thousands) Accounts receivable: Revenues from contracts with customers $ 40,837 $ 71,022 Other 4,643 7,192 Total accounts receivable $ 45,480 $ 78,214 Recent Accounting Pronouncements On January 1, 2020, the Partnership adopted Accounting Standards Update ("ASU") 2018-13, Fair Value Measurements (Topic 820), which removed, modified, and added certain required disclosures on fair value measurements. The adoption of this update had no impact on the Partnership's financial position, results of operations, or liquidity.

Oil and Natural Gas Properties

Oil and Natural Gas Properties	6 Months Ended
	Jun. 30, 2020
Business Combinations [Abstract]
Oil and Natural Gas Properties	NOTE 3 - OIL AND NATURAL GAS PROPERTIES Assets Held for Sale In June 2020, the Partnership announced it had entered into two separate agreements to sell certain mineral and royalty properties in the Permian Basin. These transactions subsequently closed in July 2020 for total proceeds, after closing adjustments, of $150.1 million. One of these transactions, effective May 1, 2020, involved the sale of the Partnership's mineral and royalty interest in specific tracts in Midland County, Texas to a private buyer for gross proceeds of approximately $55 million ("Divestiture A"). The other transaction, effective July 1, 2020, involved the sale of an undivided interest across parts of the Partnership's Delaware Basin and Midland Basin positions to Pegasus Resources, LLC, a portfolio company of EnCap Investments, for gross proceeds of approximately $100 million ("Divestiture B"). The book value of the assets divested through these transactions are classified as held for sale in the consolidated balance sheet as of June 30, 2020. Assets held for sale consisted of the following as of June 30, 2020: Divestiture A Divestiture B Total (in thousands) Accounts Receivable $ 227 $ — $ 227 Oil and natural gas properties Unproved properties 50,985 67,292 118,277 Proved properties, net 2,274 5,713 7,987 Total Assets Held for Sale $ 53,486 $ 73,005 $ 126,491 The assets held for sale as of June 30, 2020 do not qualify for discontinued operations as they do not represent a strategic shift that will have a major effect on the Partnership's operations or financial results. Acquisitions Acquisitions of proved oil and natural gas properties and working interests are generally considered business combinations and are recorded at their estimated fair value as of the acquisition date. Acquisitions that consist of all or substantially all unproved oil and natural gas properties are generally considered asset acquisitions and are recorded at cost. 2020 Acquisitions The Partnership had no acquisition activity during the six months ended June 30, 2020. 2019 Acquisitions During the year ended December 31, 2019, the Partnership closed on multiple acquisitions of mineral and royalty interests for total consideration of $44.0 million. Acquisitions that were considered business combinations were primarily located in the Permian Basin. These acquisitions were funded with borrowings under the Credit Facility (as defined in Note 6 - Credit Facility) and funds from operating activities. Acquisition related costs of less than $0.1 million were expensed and included in the General and administrative line item of the consolidated statement of operations for the year ended December 31, 2019. The following table summarizes these acquisitions: Assets Acquired Consideration Paid Proved Unproved Net Working Capital Total Fair Value Cash (in thousands) February $ 173 $ 8,437 $ 1 $ 8,611 $ 8,611 March 24 — — 24 24 June 527 3,268 — 3,795 3,795 Total fair value $ 724 $ 11,705 $ 1 $ 12,430 $ 12,430 In addition, during 2019, the Partnership acquired mineral and royalty interests that were considered asset acquisitions from various sellers for an aggregate of $31.6 million. These acquisitions were primarily located in East Texas and the Permian Basin. The cash portion of the consideration paid for these acquisitions of $30.7 million was funded with borrowings under the Credit Facility and funds from operating activities, and $0.9 million was funded through the issuance of common units of the Partnership based on the fair values of the common units issued on the acquisition dates. Farmout Agreements In 2017, the Partnership entered into two farmout arrangements designed to reduce its working interest capital expenditures and thereby significantly lower its capital spending other than for royalty and mineral acquisitions. Under these agreements, the Partnership conveyed its rights to participate in certain non-operated working interest opportunities to external capital providers while retaining value from these interests in the form of additional royalty income or retained economic interests. Canaan Farmout On February 21, 2017, the Partnership announced that it had entered into a farmout agreement with Canaan Resource Partners ("Canaan") which covers certain Haynesville and Bossier shale acreage in San Augustine County, Texas operated by XTO Energy Inc., a subsidiary of Exxon Mobil Corporation. The Partnership has an approximate 50% working interest in the acreage and is the largest mineral owner. A total of 20 wells were drilled over an initial phase, beginning with wells spud after January 1, 2017. Canaan elected to participate in an additional phase that began in September 2018 and continues for the lesser of 2 years or until 20 wells have been drilled. As of June 30, 2020, a total of 17 wells have been drilled during the second phase. After the completion of the second phase, Canaan will have the option to elect to participate in a similar third phase. During the first three phases of the agreement, Canaan commits on a phase-by-phase basis and funds 80% of the Partnership's drilling and completion costs and is assigned 80% of the Partnership's working interests in such wells (40% working interest on an 8/8ths basis) as the wells are drilled. After the third phase, Canaan can earn 40% of the Partnership’s working interest (20% working interest on an 8/8ths basis) in additional wells drilled in the area by continuing to fund 40% of the Partnership's costs for those wells on a well-by-well basis. The Partnership receives an overriding royalty interest (“ORRI”) before payout and an increased ORRI after payout on all wells drilled under the agreement. Pivotal Farmout On November 21, 2017, the Partnership entered into a farmout agreement with Pivotal Petroleum Partners (“Pivotal”), a portfolio company of Tailwater Capital, LLC. The farmout agreement covers substantially all of the Partnership's remaining working interests under active development in the Shelby Trough area of East Texas, targeting the Haynesville and Bossier shale acreage (after giving effect to the Canaan Farmout), until November 2025. Pivotal will earn the Partnership's remaining working interest in wells operated by XTO Energy Inc. in San Augustine County, Texas not covered by the Canaan Farmout (10% working interest on an 8/8th basis), as well as 100% of the Partnership's working interests (ranging from approximately 12.5% to 25% on an 8/8ths basis) in wells operated by BPX Energy in San Augustine and Angelina counties, Texas. Initially, Pivotal is obligated to fund the development of up to 80 wells, in designated well groups, across several development areas and then has options to continue funding the Partnership's working interest across those areas for the duration of the farmout agreement. Once Pivotal achieves a specified payout for a designated well group, the Partnership will obtain a majority of the original working interest in such well group. As of June 30, 2020, a total of 68 wells have been drilled in the contract area. The Partnership's development agreement with BPX Energy terminated in 2019 with respect to the majority of the Partnership's acreage covered by the farmout agreement with Pivotal. As such, Pivotal retains minimal rights or obligations related to the farmout for that area. In the second quarter of 2020, the Partnership entered into a development agreement with Aethon Energy ("Aethon") to develop certain portions of the area forfeited by BPX Energy in Angelina County, Texas. The agreement provides for minimum well commitments by Aethon in exchange for reduced royalty rates and exclusive access to our mineral and leasehold acreage in the contract area. The agreement calls for a minimum of four wells to be drilled in the initial program year, which begins in the third quarter of 2020, increasing to a minimum of 15 wells per year beginning with the third program year. The Partnership remains engaged with Pivotal around farmout opportunities in the area forfeited by BPX Energy, including the acreage covered by the Aethon development agreement. From the inception of the farmout agreements through June 30, 2020, the Partnership has received $90.3 million and $119.1 million from Canaan and Pivotal, respectively, under the agreements. When such reimbursements are received prior to assigning the wells to Canaan and Pivotal, the Partnership records the amounts as increases to Oil and natural gas properties and Other long-term liabilities. When working interests in farmout wells are assigned to Canaan and Pivotal, the Partnership's Oil and natural gas properties and Other long-term liabilities are reduced by the reimbursed capital costs. As of June 30, 2020 and December 31, 2019, $0.1 million and $1.7 million, respectively, was included in the Other long-term liabilities line item of the consolidated balance sheets for reimbursements received associated with farmed-out working interests not yet assigned to Canaan and Pivotal. Impairment of Oil and Natural Gas Properties Proved and unproved oil and natural gas properties are reviewed for impairment when events and circumstances indicate a possible decline in the recoverability of the carrying value of those properties. When assessing producing properties for impairment, the Partnership compares the expected undiscounted projected future cash flows of the producing properties to the carrying amount of the producing properties to determine recoverability. When the carrying amount exceeds its estimated undiscounted future cash flows, the carrying amount is written down to its fair value, which is measured as the present value of the projected future cash flows of such properties. There was a collapse in oil prices during the first quarter of 2020 due to geopolitical events that increased supply at the same time demand weakened due to the impact of the COVID-19 pandemic. The Partnership determined these events and circumstances indicated a possible decline in the recoverability of the carrying value of certain proved properties and recoverability testing determined that certain depletable units consisting of mature oil producing properties were impaired as of March 31, 2020. The Partnership recognized no impairment of oil and natural gas properties for the three months ended June 30, 2020 and $51.0 million of impairment of oil and natural gas properties for the six months ended June 30, 2020. No impairment of oil and natural gas properties was recognized during 2019. See Note 5 - Fair Value Measurements for further discussion.

Commodity Derivative Financial

Commodity Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Commodity Derivatives And Financial Instruments	NOTE 4 - COMMODITY DERIVATIVE FINANCIAL INSTRUMENTS The Partnership’s ongoing operations expose it to changes in the market price for oil and natural gas. To mitigate the inherent commodity price risk associated with its operations, the Partnership uses oil and natural gas commodity derivative financial instruments. From time to time, such instruments may include variable-to-fixed-price swaps, costless collars, fixed-price contracts and other contractual arrangements. The Partnership enters into oil and natural gas derivative contracts that contain netting arrangements with each counterparty. The Partnership does not enter into derivative instruments for speculative purposes. As of June 30, 2020, the Partnership’s open derivative contracts consisted of fixed-price swap contracts and costless collar contracts. A fixed-price swap contract between the Partnership and the counterparty specifies a fixed commodity price and a future settlement date. A costless collar contract between the Partnership and the counterparty specifies a floor and a ceiling commodity price and a future settlement date. The Partnership has not designated any of its contracts as fair value or cash flow hedges. Accordingly, the changes in the fair value of the contracts are included in the consolidated statement of operations in the period of the change. All derivative gains and losses from the Partnership’s derivative contracts have been recognized in revenue in the Partnership's accompanying consolidated statements of operations. Derivative instruments that have not yet been settled in cash are reflected as either derivative assets or liabilities in the Partnership’s accompanying consolidated balance sheets as of June 30, 2020 and December 31, 2019. See Note 5 - Fair Value Measurements for further discussion. The Partnership's derivative contracts expose it to credit risk in the event of nonperformance by counterparties that may adversely impact the fair value of the Partnership's commodity derivative assets. While the Partnership does not require its derivative contract counterparties to post collateral, the Partnership does evaluate the credit standing of such counterparties as deemed appropriate. This evaluation includes reviewing a counterparty’s credit rating and latest financial information. As of June 30, 2020, the Partnership had nine counterparties, all of which are rated Baa1 or better by Moody’s and are lenders under the Credit Facility. The tables below summarize the fair values and classifications of the Partnership’s derivative instruments, as well as the gross recognized derivative assets, liabilities, and amounts offset in the consolidated balance sheets as of each date: June 30, 2020 Classification Balance Sheet Location Gross Effect of Counterparty Netting Net Carrying Value on Balance Sheet (in thousands) Assets: Current asset Commodity derivative assets $ 49,258 $ (3,736) $ 45,522 Long-term asset Deferred charges and other long-term assets 610 (531) 79 Total assets $ 49,868 $ (4,267) $ 45,601 Liabilities: Current liability Commodity derivative liabilities $ 4,047 $ (3,736) $ 311 Long-term liability Commodity derivative liabilities 5,269 (531) 4,738 Total liabilities $ 9,316 $ (4,267) $ 5,049 December 31, 2019 Classification Balance Sheet Location Gross Effect of Counterparty Netting Net Carrying Value on Balance Sheet (in thousands) Assets: Current asset Commodity derivative assets $ 19,028 $ (4,238) $ 14,790 Long-term asset Deferred charges and other long-term assets 713 (105) 608 Total assets $ 19,741 $ (4,343) $ 15,398 Liabilities: Current liability Commodity derivative liabilities $ 4,397 $ (4,238) $ 159 Long-term liability Commodity derivative liabilities 123 (105) 18 Total liabilities $ 4,520 $ (4,343) $ 177 Changes in the fair values of the Partnership’s derivative instruments (both assets and liabilities) are presented on a net basis in the accompanying consolidated statements of operations and consolidated statements of cash flows and consist of the following for the periods presented: Three Months Ended June 30, Six Months Ended June 30, Derivatives not designated as hedging instruments 2020 2019 2020 2019 (in thousands) Beginning fair value of commodity derivative instruments $ 96,278 $ 5,112 $ 15,221 $ 48,038 Gain (loss) on oil derivative instruments (21,647) 7,905 56,164 (31,356) Gain (loss) on natural gas derivative instruments 2,473 21,282 14,673 19,360 Net cash paid (received) on settlements of oil derivative instruments (26,776) 1,745 (28,317) (2,810) Net cash paid (received) on settlements of natural gas derivative instruments (9,776) (4,676) (17,189) (1,864) Net change in fair value of commodity derivative instruments (55,726) 26,256 25,331 (16,670) Ending fair value of commodity derivative instruments $ 40,552 $ 31,368 $ 40,552 $ 31,368 The Partnership had the following open derivative contracts for oil as of June 30, 2020: Weighted Average Price (Per Bbl) Range (Per Bbl) Period and Type of Contract Volume (Bbl) Low High Oil Swap Contracts: 2020 Second Quarter 210,000 $ 57.32 $ 54.92 $ 58.65 Third Quarter 630,000 57.32 54.92 58.65 Fourth Quarter 630,000 57.32 54.92 58.65 2021 First Quarter 480,000 $ 36.18 $ 32.64 $ 37.92 Second Quarter 480,000 36.18 32.64 37.92 Third Quarter 480,000 36.18 32.64 37.92 Fourth Quarter 480,000 36.18 32.64 37.92 Weighted Average Weighted Average Period and Type of Contract Volume (Bbl) Oil Collar Contracts: 2020 Second Quarter 70,000 $ 56.43 $ 67.14 Third Quarter 210,000 56.43 67.14 Fourth Quarter 210,000 56.43 67.14 The Partnership had the following open derivative contracts for natural gas as of June 30, 2020: Weighted Average Price (Per MMBtu) Range (Per MMBtu) Period and Type of Contract Volume (MMBtu) Low High Natural Gas Swap Contracts: 2020 Third Quarter 10,120,000 $ 2.69 $ 2.55 $ 2.74 Fourth Quarter 10,120,000 2.69 2.55 2.74 2021 First Quarter 7,200,000 $ 2.60 $ 2.52 $ 2.72 Second Quarter 7,280,000 2.60 2.52 2.72 Third Quarter 7,360,000 2.60 2.52 2.72 Fourth Quarter 7,360,000 2.60 2.52 2.72

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 5 - FAIR VALUE MEASUREMENTS Fair value is defined as the amount at which an asset (or liability) could be bought (or incurred) or sold (or settled) in an orderly transaction between market participants at the measurement date. Further, ASC 820, Fair Value Measurement , establishes a framework for measuring fair value, establishes a fair value hierarchy based on the quality of inputs used to measure fair value, and includes certain disclosure requirements. Fair value estimates are based on either (i) actual market data or (ii) assumptions that other market participants would use in pricing an asset or liability, including estimates of risk. ASC 820 establishes a three-level valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy categorizes assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. The three levels are defined as follows: Level 1 —Unadjusted quoted prices for identical assets or liabilities in active markets. Level 2 —Quoted prices for similar assets or liabilities in non-active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Level 3 —Inputs that are unobservable and significant to the fair value measurement (including the Partnership’s own assumptions in determining fair value). A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Partnership’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. The carrying value of the Partnership's cash and cash equivalents, receivables, and payables approximate fair value due to the short-term nature of the instruments. The estimated carrying value of all debt as of June 30, 2020 and December 31, 2019 approximated the fair value due to variable market rates of interest. These debt fair values, which are Level 3 measurements, were estimated based on the Partnership’s incremental borrowing rates for similar types of borrowing arrangements, when quoted market prices were not available. The estimated fair values of the Partnership’s financial instruments are not necessarily indicative of the amounts that would be realized in a current market exchange. Assets and Liabilities Measured at Fair Value on a Recurring Basis The Partnership estimated the fair value of derivative instruments using the market approach via a model that uses inputs that are observable in the market or can be derived from, or corroborated by, observable data. See Note 4 - Commodity Derivative Financial Instruments for further discussion. The following table presents information about the Partnership’s assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Using Effect of Counterparty Netting Total Level 1 Level 2 Level 3 (in thousands) As of June 30, 2020 Financial Assets Commodity derivative instruments $ — $ 49,868 $ — $ (4,267) $ 45,601 Financial Liabilities Commodity derivative instruments $ — $ 9,316 $ — $ (4,267) $ 5,049 As of December 31, 2019 Financial Assets Commodity derivative instruments $ — $ 19,741 $ — $ (4,343) $ 15,398 Financial Liabilities Commodity derivative instruments $ — $ 4,520 $ — $ (4,343) $ 177 Assets and Liabilities Measured at 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 and measurements of oil and natural gas property values for assessment of impairment. The determination of the fair values of proved and unproved properties acquired in business combinations are estimated by discounting projected future cash flows. The factors used to determine fair value include estimates of economic reserves, future operating and development costs, future commodity prices, timing of future production, and a risk-adjusted discount rate. The Partnership has designated these measurements as Level 3. The Partnership’s fair value assessments for recent acquisitions are included in Note 3 - Oil and Natural Gas Properties. Oil and natural gas properties are measured at fair value on a non-recurring basis using the income approach when assessing for impairment. The factors used to determine fair value include estimates of proved reserves, future commodity prices, timing of future production, operating costs, future capital expenditures, and a risk-adjusted discount rate. The Partnership estimated the fair value of the impaired properties using published forward commodity price curves as of the measurement date of March 31, 2020, considering locational and quality differentials based on a review of historical realizations, and using an annual discount rate of 8%. The following table presents information about the non-recurring fair value measurements of the impaired properties: Fair Value Measurements Using Impairment Level 1 Level 2 Level 3 (in thousands) Three Months Ended June 30, 2020 Impaired oil and natural gas properties $ — $ — $ — $ — Three Months Ended June 30, 2019 Impaired oil and natural gas properties $ — $ — $ — $ — Six Months Ended June 30, 2020 Impaired oil and natural gas properties $ — $ — $ 2,044 $ 51,031 Six Months Ended June 30, 2019 Impaired oil and natural gas properties $ — $ — $ — $ — The Partnership’s estimates of fair value have been determined at discrete points in time based on relevant market data. These estimates involve uncertainty, particularly in the current volatile market, and cannot be determined with precision. Changes to these estimates, particularly related to economic reserves, future commodity prices, and timing of future production could result in additional impairment charges in the future. There were no significant changes in valuation techniques or related inputs as of June 30, 2020 or December 31, 2019.

Credit Facility

Credit Facility	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Credit Facility	NOTE 6 - CREDIT FACILITY The Partnership maintains a senior secured revolving credit agreement, as amended (the “Credit Facility”). The Credit Facility has an aggregate maximum credit amount of $1.0 billion and terminates on November 1, 2022. The commitment of the lenders equals the lesser of the aggregate maximum credit amount and the borrowing base. The amount of the borrowing base is redetermined semi-annually, usually in October and April, and is derived from the value of the Partnership’s oil and natural gas properties as determined by the lender syndicate using pricing assumptions that often differ from the current market for future prices. The Partnership and the lenders (at the direction of two-thirds of the lenders) each have discretion to request a borrowing base redetermination one time between scheduled redeterminations. Effective October 23, 2019 the borrowing base redetermination reduced the borrowing base from $675.0 million to $650.0 million and, effective May 1, 2020, the borrowing base was further reduced to $460.0 million. Effective July 21, 2020, in connection with the closing of the Partnership's two asset sales in the Permian Basin, the borrowing base was further reduced to $430.0 million. Outstanding borrowings under the Credit Facility bear interest at a floating rate elected by the Partnership equal to an alternative base rate (which is equal to the greatest of the Prime Rate, the Federal Funds effective rate plus 0.50%, or 1-month LIBOR plus 1.00%) or LIBOR, in each case, plus the applicable margin. The applicable margin for the alternative base rate ranges from 0.75% to 1.75% and the applicable margin for LIBOR ranges from 1.75% to 2.75%, depending on the borrowings outstanding in relation to the borrowing base. The weighted-average interest rate of the Credit Facility was 2.43% and 4.05% as of June 30, 2020 and December 31, 2019, respectively. Accrued interest is payable at the end of each calendar quarter or at the end of each interest period, unless the interest period is longer than 90 days, in which case interest is payable at the end of every 90-day period. In addition, a commitment fee is payable at the end of each calendar quarter based on either a rate of 0.375% if the borrowing base utilization percentage is less than 50%, or 0.500% if the borrowing base utilization percentage is equal to or greater than 50%. The Credit Facility is secured by substantially all of the Partnership’s oil and natural gas production and assets. The Credit Facility contains various limitations on future borrowings, leases, hedging, and sales of assets. Additionally, the Credit Facility requires the Partnership to maintain a current ratio of not less than 1.0:1.0 and a ratio of total debt to EBITDAX (Earnings before Interest, Taxes, Depreciation, Amortization, and Exploration) of not more than 3.5:1.0. As of June 30, 2020, the Partnership was in compliance with all financial covenants in the Credit Facility. The aggregate principal balance outstanding was $323.0 million and $394.0 million at June 30, 2020 and December 31, 2019, respectively. The unused portion of the available borrowings under the Credit Facility were $137.0 million and $256.0 million at June 30, 2020 and December 31, 2019, respectively.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 7 - COMMITMENTS AND CONTINGENCIES Environmental Matters The Partnership’s business includes activities that are subject to U.S. federal, state, and local environmental regulations with regard to air, land, and water quality and other environmental matters. The Partnership does not consider the potential remediation costs that could result from issues identified in any environmental site assessments to be significant to the consolidated financial statements, and no provision for potential remediation costs has been recorded. Put Option Related to Noble Acquisition By acquiring 100% of the issued and outstanding securities of Samedan Royalty, LLC, now NAMP Holdings, LLC, on November 28, 2017 from Noble Energy US Holdings, LLC, the Partnership acquired a 100% interest in Comin-Temin, LLC, now NAMP GP, LLC ("Holdings"), Comin 1989 Partnership LLLP, now NAMP 1, LP ("Comin"), and Temin 1987 Partnership LLLP, now NAMP 2, LP ("Temin"). Pursuant to certain co-ownership agreements, various co-owners hold undivided beneficial ownership interests in 45.33% and 42.63% of the mineral interests obtained by the Partnership through the acquisition of Holdings and Temin, respectively as of June 30, 2020. Based on the terms of the co-ownership agreements, the co-owners each have an unconditional option to require Comin or Temin, as applicable, to purchase their beneficial ownership interest in these mineral interests, as applicable, at any time within 30 days of receiving such repurchase notice. The purchase price of the beneficial ownership interest shall be based on an evaluation performed by Comin or Temin, as applicable, in good faith. As of June 30, 2020, the Partnership had not received notice from any co-owners to exercise their repurchase option, and as such, no liability was recorded. Litigation

Incentive Compensation

Incentive Compensation	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Incentive Compensation	NOTE 8 - INCENTIVE COMPENSATION The table below summarizes incentive compensation expense recorded in the General and administrative line item of the consolidated statements of operations for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands) Cash—short and long-term incentive plans $ 506 $ 1,471 $ 1,469 $ 3,243 Equity-based compensation—restricted common units 1,126 2,591 2,411 5,610 Equity-based compensation—restricted performance units 1 1,098 637 (3,559) 6,257 Board of Directors incentive plan 250 587 728 1,172 Total incentive compensation expense $ 2,980 $ 5,286 $ 1,049 $ 16,282 1 Compensation expense related to the restricted performance awards is determined using the measurement-date (i.e., the last day of each reporting period date) fair value of the Partnership's common units. Downward cost revisions recognized in the six months ended June 30, 2020 are due to the decrease in the Partnership's common unit price period over period.

Redeemable Preferred Units

Redeemable Preferred Units	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Preferred Units	NOTE 9 - PREFERRED UNITS Series B Cumulative Convertible Preferred Units On November 28, 2017, the Partnership issued and sold in a private placement 14,711,219 Series B cumulative convertible preferred units representing limited partner interests in the Partnership for a cash purchase price of $20.3926 per Series B cumulative convertible preferred unit, resulting in total proceeds of approximately $300.0 million. The Series B cumulative convertible preferred units are entitled to an annual distribution of 7%, payable on a quarterly basis in arrears. The Series B cumulative convertible preferred units may be converted by each holder at its option, in whole or in part, into common units on a one-for-one basis at the purchase price of $20.3926, adjusted to give effect to any accrued but unpaid accumulated distributions on the applicable Series B cumulative convertible preferred units through the most recent declaration date. However, the Partnership shall not be obligated to honor any request for such conversion if such request does not involve an underlying value of common units of at least $10.0 million based on the closing trading price of common units on the trading day immediately preceding the conversion notice date, or such lesser amount to the extent such exercise covers all of a holder's Series B cumulative convertible preferred units.

Earnings Per Unit

Earnings Per Unit	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Unit	NOTE 10 - EARNINGS PER UNIT The Partnership applies the two-class method for purposes of calculating earnings per unit (“EPU”). The holders of the Partnership’s restricted common units have all the rights of a unitholder, including non-forfeitable distribution rights. As participating securities, the restricted common units are included in the calculation of basic earnings per unit. For the periods presented, the amount of earnings allocated to these participating units was not material. Net income (loss) attributable to the Partnership is allocated to the Partnership’s general partner and the common and subordinated unitholders in proportion to their pro rata ownership after giving effect to distributions, if any, declared during the period. The Partnership assesses the Series B cumulative convertible preferred units on an as-converted basis for the purpose of calculating diluted EPU. The Partnership’s restricted performance unit awards are contingently issuable units that are considered in the calculation of diluted EPU. The Partnership assesses the number of units that would be issuable, if any, under the terms of the arrangement if the end of the reporting period were the end of the contingency period. The following table sets forth the computation of basic and diluted earnings per common and subordinated unit: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands, except per unit amounts) NET INCOME (LOSS) $ (8,371) $ 95,087 $ 67,741 $ 104,104 Distributions on Series B cumulative convertible preferred units (5,250) (5,250) (10,500) (10,500) NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND COMMON AND SUBORDINATED UNITS (13,621) 89,837 57,241 93,604 ALLOCATION OF NET INCOME (LOSS): General partner interest $ — $ — $ — $ — Common units (13,621) 67,718 57,241 69,611 Subordinated units — 22,119 — 23,993 $ (13,621) $ 89,837 $ 57,241 $ 93,604 Weighted average common units outstanding: Weighted average common units outstanding (basic) 206,707 150,101 206,669 129,873 Effect of dilutive securities — 14,969 — — Weighted average common units outstanding (diluted) 206,707 165,070 206,669 129,873 Weighted average subordinated units outstanding: Weighted average subordinated units outstanding (basic) — 56,104 — 76,105 Effect of dilutive securities — — — — Weighted average subordinated units outstanding (diluted) — 56,104 — 76,105 NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER COMMON AND SUBORDINATED UNIT: Per common unit (basic) $ (0.07) $ 0.45 $ 0.28 $ 0.54 Per subordinated unit (basic) — 0.39 — 0.32 Per common unit (diluted) 1 (0.07) 0.44 0.28 0.54 Per subordinated unit (diluted) — 0.39 — 0.32 1 For the three months ended June 30, 2019, diluted net income (loss) attributable to common units included distributions on Series B cumulative convertible preferred units of $5.3 million. The following units of potentially dilutive securities were excluded from the computation of diluted weighted average units outstanding because their inclusion would be anti-dilutive: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands) Potentially dilutive securities (common units): Series B cumulative convertible preferred units on an as-converted basis 14,969 — 14,969 14,969

Common and Subordinated Units

Common and Subordinated Units	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Common and Subordinated Units	NOTE 11 - COMMON AND SUBORDINATED UNITS Common and Subordinated Units The common units and subordinated units represent limited partner interests in the Partnership. The partnership agreement restricts unitholders’ voting rights by providing that any units held by a person or group that owns 15% or more of any class of units then outstanding, other than the limited partners in Black Stone Minerals Company, L.P. prior to the initial public offering of BSM, their transferees, persons who acquired such units with the prior approval of the board of directors of the Partnership's general partner (the "Board"), holders of Series B cumulative convertible preferred units in connection with any vote, consent or approval of the Series B cumulative convertible preferred units as a separate class, and persons who own 15% or more of any class as a result of any redemption or purchase of any other person's units or similar action by the Partnership or any conversion of the Series B cumulative convertible preferred units at the Partnership's option or in connection with a change of control, may not vote on any matter. The holders of common units are and, prior to the end of the subordination period (as defined in the partnership agreement), the subordinated units were, entitled to participate in distributions and exercise the rights and privileges provided to limited partners holding common units and subordinated units, respectively, under the partnership agreement. The subordination period under the partnership agreement ended on the first business day after the Partnership earned and paid an aggregate amount of at least $1.35 (the annualized minimum quarterly distribution applicable for quarterly periods ending March 31, 2019 and thereafter) multiplied by the total number of outstanding common and subordinated units for a period of four consecutive, non-overlapping quarters ending on or after March 31, 2019, and there were no outstanding arrearages on the common units. This test was met upon the payment of the distribution for the first quarter of 2019. Accordingly, each outstanding subordinated unit converted into one common unit on May 24, 2019 and the priority right of the common unitholders ceased to exist. The partnership agreement generally provides that any distributions are paid each quarter in the following manner: • first , to the holders of the Series B cumulative convertible preferred units in an amount equal to 7% per annum, subject to certain adjustments; and • second , to the holders of common units. The following table provides information about the Partnership's per unit distributions to common and subordinated unitholders: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 DISTRIBUTIONS DECLARED AND PAID: Per common unit $ 0.0800 $ 0.3700 $ 0.3800 $ 0.7400 Per subordinated unit — 0.3700 — 0.7400 Common Unit Repurchase Program On November 5, 2018, the Board authorized the repurchase of up to $75.0 million in common units. The repurchase program authorizes the Partnership to make repurchases on a discretionary basis as determined by management, subject to market conditions, applicable legal requirements, available liquidity, and other appropriate factors. The Partnership made no repurchases under this program for the six months ended June 30, 2020. As of June 30, 2020, the Partnership has repurchased $4.2 million in common units under the repurchase program since inception. The repurchase program is funded from the Partnership's cash on hand or availability on the Credit Facility. Any repurchased units are canceled.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	NOTE 12 - SUBSEQUENT EVENTS On July 27, 2020, the Board approved a distribution for the three months ended June 30, 2020 of $0.15 per common unit. Distributions will be payable on August 21, 2020 to unitholders of record at the close of business on August 14, 2020.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim consolidated financial statements of the Partnership have been prepared in accordance with generally accepted accounting principles ("GAAP") in the United States and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). These unaudited interim consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and, therefore, do not include all disclosures required for financial statements prepared in conformity with GAAP. Accordingly, the accompanying unaudited interim consolidated financial statements and related notes should be read in conjunction with the Partnership’s consolidated financial statements included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2019 ("2019 Annual Report on Form 10-K"). The unaudited interim consolidated financial statements include the consolidated results of the Partnership. The results of operations for the six months ended June 30, 2020 are not necessarily indicative of the results to be expected for the full year. In the opinion of management, all adjustments, which are of a normal and recurring nature, necessary for the fair presentation of the financial results for all periods presented have been reflected. All intercompany balances and transactions have been eliminated. The Partnership evaluates the significant terms of its investments to determine the method of accounting to be applied to each respective investment. Investments in which the Partnership has less than a 20% ownership interest and does not have control or exercise significant influence are accounted for using fair value or cost minus impairment if fair value is not readily determinable. Investments in which the Partnership exercises control are consolidated, and the noncontrolling interests of such investments, which are not attributable directly or indirectly to the Partnership, are presented as a separate component of net income (loss) and equity. The unaudited interim consolidated financial statements include undivided interests in oil and natural gas property rights. The Partnership accounts for its share of oil and natural gas property rights by reporting its proportionate share of assets, liabilities, revenues, costs, and cash flows within the relevant lines on the accompanying unaudited interim consolidated balance sheets, statements of operations, and statements of cash flows.
Segment Reporting	Segment Reporting The Partnership operates in a single operating and reportable segment. Operating segments are defined as components of an enterprise for which separate financial information is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assess performance. The Partnership’s chief executive officer has been determined to be the chief operating decision maker and allocates resources and assesses performance based upon financial information at the consolidated level.
Recent Accounting Pronouncements	Recent Accounting Pronouncements On January 1, 2020, the Partnership adopted Accounting Standards Update ("ASU") 2018-13, Fair Value Measurements (Topic 820), which removed, modified, and added certain required disclosures on fair value measurements. The adoption of this update had no impact on the Partnership's financial position, results of operations, or liquidity.
Earnings Per Unit	The Partnership applies the two-class method for purposes of calculating earnings per unit (“EPU”). The holders of the Partnership’s restricted common units have all the rights of a unitholder, including non-forfeitable distribution rights. As participating securities, the restricted common units are included in the calculation of basic earnings per unit. For the periods presented, the amount of earnings allocated to these participating units was not material. Net income (loss) attributable to the Partnership is allocated to the Partnership’s general partner and the common and subordinated unitholders in proportion to their pro rata ownership after giving effect to distributions, if any, declared during the period.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - (Tables)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Schedule of Accounts Receivable	The following table presents information about the Partnership's accounts receivable: June 30, 2020 December 31, 2019 (in thousands) Accounts receivable: Revenues from contracts with customers $ 40,837 $ 71,022 Other 4,643 7,192 Total accounts receivable $ 45,480 $ 78,214

Oil and Natural Gas Properties

Oil and Natural Gas Properties (Tables)	6 Months Ended
	Jun. 30, 2020
Business Combinations [Abstract]
Assets Held for Sale	Assets held for sale consisted of the following as of June 30, 2020: Divestiture A Divestiture B Total (in thousands) Accounts Receivable $ 227 $ — $ 227 Oil and natural gas properties Unproved properties 50,985 67,292 118,277 Proved properties, net 2,274 5,713 7,987 Total Assets Held for Sale $ 53,486 $ 73,005 $ 126,491
Schedule of Fair Values of the Properties Acquired	The following table summarizes these acquisitions: Assets Acquired Consideration Paid Proved Unproved Net Working Capital Total Fair Value Cash (in thousands) February $ 173 $ 8,437 $ 1 $ 8,611 $ 8,611 March 24 — — 24 24 June 527 3,268 — 3,795 3,795 Total fair value $ 724 $ 11,705 $ 1 $ 12,430 $ 12,430

Commodity Derivative Financia_2

Commodity Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Fair Value and Classification of Derivative Instruments	The tables below summarize the fair values and classifications of the Partnership’s derivative instruments, as well as the gross recognized derivative assets, liabilities, and amounts offset in the consolidated balance sheets as of each date: June 30, 2020 Classification Balance Sheet Location Gross Effect of Counterparty Netting Net Carrying Value on Balance Sheet (in thousands) Assets: Current asset Commodity derivative assets $ 49,258 $ (3,736) $ 45,522 Long-term asset Deferred charges and other long-term assets 610 (531) 79 Total assets $ 49,868 $ (4,267) $ 45,601 Liabilities: Current liability Commodity derivative liabilities $ 4,047 $ (3,736) $ 311 Long-term liability Commodity derivative liabilities 5,269 (531) 4,738 Total liabilities $ 9,316 $ (4,267) $ 5,049 December 31, 2019 Classification Balance Sheet Location Gross Effect of Counterparty Netting Net Carrying Value on Balance Sheet (in thousands) Assets: Current asset Commodity derivative assets $ 19,028 $ (4,238) $ 14,790 Long-term asset Deferred charges and other long-term assets 713 (105) 608 Total assets $ 19,741 $ (4,343) $ 15,398 Liabilities: Current liability Commodity derivative liabilities $ 4,397 $ (4,238) $ 159 Long-term liability Commodity derivative liabilities 123 (105) 18 Total liabilities $ 4,520 $ (4,343) $ 177
Changes in Fair Value of Company's Commodity Derivative Instruments	Changes in the fair values of the Partnership’s derivative instruments (both assets and liabilities) are presented on a net basis in the accompanying consolidated statements of operations and consolidated statements of cash flows and consist of the following for the periods presented: Three Months Ended June 30, Six Months Ended June 30, Derivatives not designated as hedging instruments 2020 2019 2020 2019 (in thousands) Beginning fair value of commodity derivative instruments $ 96,278 $ 5,112 $ 15,221 $ 48,038 Gain (loss) on oil derivative instruments (21,647) 7,905 56,164 (31,356) Gain (loss) on natural gas derivative instruments 2,473 21,282 14,673 19,360 Net cash paid (received) on settlements of oil derivative instruments (26,776) 1,745 (28,317) (2,810) Net cash paid (received) on settlements of natural gas derivative instruments (9,776) (4,676) (17,189) (1,864) Net change in fair value of commodity derivative instruments (55,726) 26,256 25,331 (16,670) Ending fair value of commodity derivative instruments $ 40,552 $ 31,368 $ 40,552 $ 31,368
Summary of Open Derivative Contracts	The Partnership had the following open derivative contracts for oil as of June 30, 2020: Weighted Average Price (Per Bbl) Range (Per Bbl) Period and Type of Contract Volume (Bbl) Low High Oil Swap Contracts: 2020 Second Quarter 210,000 $ 57.32 $ 54.92 $ 58.65 Third Quarter 630,000 57.32 54.92 58.65 Fourth Quarter 630,000 57.32 54.92 58.65 2021 First Quarter 480,000 $ 36.18 $ 32.64 $ 37.92 Second Quarter 480,000 36.18 32.64 37.92 Third Quarter 480,000 36.18 32.64 37.92 Fourth Quarter 480,000 36.18 32.64 37.92 Weighted Average Weighted Average Period and Type of Contract Volume (Bbl) Oil Collar Contracts: 2020 Second Quarter 70,000 $ 56.43 $ 67.14 Third Quarter 210,000 56.43 67.14 Fourth Quarter 210,000 56.43 67.14 The Partnership had the following open derivative contracts for natural gas as of June 30, 2020: Weighted Average Price (Per MMBtu) Range (Per MMBtu) Period and Type of Contract Volume (MMBtu) Low High Natural Gas Swap Contracts: 2020 Third Quarter 10,120,000 $ 2.69 $ 2.55 $ 2.74 Fourth Quarter 10,120,000 2.69 2.55 2.74 2021 First Quarter 7,200,000 $ 2.60 $ 2.52 $ 2.72 Second Quarter 7,280,000 2.60 2.52 2.72 Third Quarter 7,360,000 2.60 2.52 2.72 Fourth Quarter 7,360,000 2.60 2.52 2.72

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents information about the Partnership’s assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Using Effect of Counterparty Netting Total Level 1 Level 2 Level 3 (in thousands) As of June 30, 2020 Financial Assets Commodity derivative instruments $ — $ 49,868 $ — $ (4,267) $ 45,601 Financial Liabilities Commodity derivative instruments $ — $ 9,316 $ — $ (4,267) $ 5,049 As of December 31, 2019 Financial Assets Commodity derivative instruments $ — $ 19,741 $ — $ (4,343) $ 15,398 Financial Liabilities Commodity derivative instruments $ — $ 4,520 $ — $ (4,343) $ 177
Fair Value Measurements, Nonrecurring	The following table presents information about the non-recurring fair value measurements of the impaired properties: Fair Value Measurements Using Impairment Level 1 Level 2 Level 3 (in thousands) Three Months Ended June 30, 2020 Impaired oil and natural gas properties $ — $ — $ — $ — Three Months Ended June 30, 2019 Impaired oil and natural gas properties $ — $ — $ — $ — Six Months Ended June 30, 2020 Impaired oil and natural gas properties $ — $ — $ 2,044 $ 51,031 Six Months Ended June 30, 2019 Impaired oil and natural gas properties $ — $ — $ — $ —

Incentive Compensation (Tables)

Incentive Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Summary of Incentive Compensation Expense	The table below summarizes incentive compensation expense recorded in the General and administrative line item of the consolidated statements of operations for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands) Cash—short and long-term incentive plans $ 506 $ 1,471 $ 1,469 $ 3,243 Equity-based compensation—restricted common units 1,126 2,591 2,411 5,610 Equity-based compensation—restricted performance units 1 1,098 637 (3,559) 6,257 Board of Directors incentive plan 250 587 728 1,172 Total incentive compensation expense $ 2,980 $ 5,286 $ 1,049 $ 16,282 1 Compensation expense related to the restricted performance awards is determined using the measurement-date (i.e., the last day of each reporting period date) fair value of the Partnership's common units. Downward cost revisions recognized in the six months ended June 30, 2020 are due to the decrease in the Partnership's common unit price period over period.

Earnings Per Unit (Tables)

Earnings Per Unit (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings per Common and Subordinated Unit	The following table sets forth the computation of basic and diluted earnings per common and subordinated unit: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands, except per unit amounts) NET INCOME (LOSS) $ (8,371) $ 95,087 $ 67,741 $ 104,104 Distributions on Series B cumulative convertible preferred units (5,250) (5,250) (10,500) (10,500) NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND COMMON AND SUBORDINATED UNITS (13,621) 89,837 57,241 93,604 ALLOCATION OF NET INCOME (LOSS): General partner interest $ — $ — $ — $ — Common units (13,621) 67,718 57,241 69,611 Subordinated units — 22,119 — 23,993 $ (13,621) $ 89,837 $ 57,241 $ 93,604 Weighted average common units outstanding: Weighted average common units outstanding (basic) 206,707 150,101 206,669 129,873 Effect of dilutive securities — 14,969 — — Weighted average common units outstanding (diluted) 206,707 165,070 206,669 129,873 Weighted average subordinated units outstanding: Weighted average subordinated units outstanding (basic) — 56,104 — 76,105 Effect of dilutive securities — — — — Weighted average subordinated units outstanding (diluted) — 56,104 — 76,105 NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER COMMON AND SUBORDINATED UNIT: Per common unit (basic) $ (0.07) $ 0.45 $ 0.28 $ 0.54 Per subordinated unit (basic) — 0.39 — 0.32 Per common unit (diluted) 1 (0.07) 0.44 0.28 0.54 Per subordinated unit (diluted) — 0.39 — 0.32
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following units of potentially dilutive securities were excluded from the computation of diluted weighted average units outstanding because their inclusion would be anti-dilutive: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands) Potentially dilutive securities (common units): Series B cumulative convertible preferred units on an as-converted basis 14,969 — 14,969 14,969

Common and Subordinated Units (

Common and Subordinated Units (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Distributions Made to Limited Partner, by Distribution	The following table provides information about the Partnership's per unit distributions to common and subordinated unitholders: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 DISTRIBUTIONS DECLARED AND PAID: Per common unit $ 0.0800 $ 0.3700 $ 0.3800 $ 0.7400 Per subordinated unit — 0.3700 — 0.7400

Business and Basis of Present_2

Business and Basis of Presentation - Additional Information (Details)	Jun. 30, 2020state
Limited Partners Capital Account [Line Items]
Cost basis, ownership percentage	20.00%
U.S.
Limited Partners Capital Account [Line Items]
Number of states major onshore oil and natural gas basins located	41

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 45,480	$ 78,214
Revenues from contracts with customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	40,837	71,022
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 4,643	$ 7,192

Oil and Natural Gas Propertie_2

Oil and Natural Gas Properties - Additional Information (Details)	May 01, 2020USD ($)	Nov. 21, 2017well	Feb. 21, 2017wellphase	Jul. 31, 2020USD ($)	Sep. 30, 2020well	Jun. 30, 2020USD ($)wellnumberOfAgreements	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)wellnumberOfAgreements	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2017arrangements
Business Acquisition [Line Items]
Number of Agreements | numberOfAgreements						2		2
Acquisition-related costs										$ 100,000
Number of arrangements | arrangements											2
Impairment of oil and natural gas properties						$ 0	$ 0	$ 51,031,000	$ 0
Business combination, consideration transferred										44,000,000
Permian Basin | Disposal Group, Held-for-sale, Not Discontinued Operations | Subsequent Event
Business Acquisition [Line Items]
Proceeds from sale of property held-for-sale				$ 150,100,000
East Texas
Business Acquisition [Line Items]
Payments to acquire oil, mineral, and royalty interests										31,600,000
2019 Acquisitions
Business Acquisition [Line Items]
Payments to acquire oil, mineral, and royalty interests										30,700,000
Issuance of common units, net of offering costs										900,000
Angelina County, Texas | Farmout Agreement
Business Acquisition [Line Items]
Business combination, ownership interest, acreage, percent			50.00%
Exploratory wells, expected to be drilled | well			20
Oil, productive well, number of wells, net | well						17		17
Exploratory wells, additional wells to be drilled | well			20
Asset acquisition, number of phases | phase			3
Midland County, Texas | Divestiture A | Disposal Group, Held-for-sale, Not Discontinued Operations
Business Acquisition [Line Items]
Proceeds from sale of property held-for-sale	$ 55,000,000
Midland County, Texas | Divestiture B | Disposal Group, Held-for-sale, Not Discontinued Operations
Business Acquisition [Line Items]
Proceeds from sale of property held-for-sale	$ 100,000,000
Canaan Resource Partners | Angelina County, Texas | Farmout Agreement
Business Acquisition [Line Items]
Asset acquisition, term of phase			2 years
Asset acquisition, funding requirements, drilling and completion costs, percent			80.00%
Asset acquisition, ownership interest in wells, percent			80.00%
Asset acquisition, ownership interest, gross, percent			40.00%
Asset acquisition, third phase, ownership interest in additional wells, percent			40.00%
Asset acquisition, third phase, ownership interest in additional wells, gross, percent			20.00%
Asset acquisition, third phase, funding requirements, drilling and completion costs, percent			40.00%
Business combination, pro forma information, revenue of acquiree since acquisition date, actual								$ 90,300,000
Pivotal | San Augustine County, Texas | Farmout Agreement
Business Acquisition [Line Items]
Exploratory wells, expected to be drilled | well		80
Oil, productive well, number of wells, net | well						68		68
Asset acquisition, ownership interest, gross, percent		10.00%
Asset acquisition, ownership interest, in wells operated by others, percent		100.00%
Business combination, pro forma information, revenue of acquiree since acquisition date, actual								$ 119,100,000
Pivotal | San Augustine County, Texas | Farmout Agreement | Subsequent Event
Business Acquisition [Line Items]
Exploratory wells, expected to be drilled | well					4
Exploratory wells, expected to be drilled per year | well					15
Other long-term liabilities | Canaan Resource Partners | Angelina County, Texas | Farmout Agreement
Business Acquisition [Line Items]
Business combination, pro forma information, working interests in wells drilled and completed, actual								$ 100,000		$ 1,700,000
Minimum | Pivotal | San Augustine County, Texas | Farmout Agreement
Business Acquisition [Line Items]
Asset acquisition, ownership interest, in wells operated by others, gross, percent		12.50%
Maximum | Pivotal | San Augustine County, Texas | Farmout Agreement
Business Acquisition [Line Items]
Asset acquisition, ownership interest, in wells operated by others, gross, percent		25.00%

Oil and Natural Gas Propertie_3

Oil and Natural Gas Properties - Assets Held for Sale (Details) $ in Thousands	Jun. 30, 2020USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts Receivable	$ 227
Oil and Gas Property [Abstract]
Unproved properties	118,277
Proved properties, net	7,987
Assets held for sale	126,491
Divestiture A
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts Receivable	227
Oil and Gas Property [Abstract]
Unproved properties	50,985
Proved properties, net	2,274
Assets held for sale	53,486
Divestiture B
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts Receivable	0
Oil and Gas Property [Abstract]
Unproved properties	67,292
Proved properties, net	5,713
Assets held for sale	$ 73,005

Oil and Natural Gas Propertie_4

Oil and Natural Gas Properties - Schedule of Fair Values of the Properties Acquired (Details) - Permian Basin - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Feb. 28, 2019	Dec. 31, 2019
Business Acquisition [Line Items]
Proved	$ 527	$ 24	$ 173	$ 724
Unproved	3,268	0	8,437	11,705
Net Working Capital	0	0	1	1
Total Fair Value	3,795	24	8,611	12,430
Consideration Paid	$ 3,795	$ 24	$ 8,611	$ 12,430

Commodity Derivative Financia_3

Commodity Derivative Financial Instruments - Additional Information (Details)	Jun. 30, 2020counterparty
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Number of counterparties	9

Commodity Derivative Financia_4

Commodity Derivative Financial Instruments - Summary of Fair Value and Classification of Derivative Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Derivatives Fair Value [Line Items]
Gross Fair Value, Assets	$ 49,868	$ 19,741
Effect of Counterparty Netting, Assets	(4,267)	(4,343)
Total net carrying value on Balance Sheet, assets	45,601	15,398
Gross Fair Value, Liabilities	9,316	4,520
Effect of Counterparty Netting, Liabilities	(4,267)	(4,343)
Total net carrying value on Balance Sheet, liabilities	5,049	177
Commodity derivative assets
Derivatives Fair Value [Line Items]
Gross Fair Value, Assets	49,258	19,028
Effect of Counterparty Netting, Assets	(3,736)	(4,238)
Total net carrying value on Balance Sheet, assets	45,522	14,790
Deferred charges and other long-term assets
Derivatives Fair Value [Line Items]
Gross Fair Value, Assets	610	713
Effect of Counterparty Netting, Assets	(531)	(105)
Total net carrying value on Balance Sheet, assets	79	608
Commodity derivative liabilities
Derivatives Fair Value [Line Items]
Gross Fair Value, Liabilities	4,047	4,397
Effect of Counterparty Netting, Liabilities	(3,736)	(4,238)
Total net carrying value on Balance Sheet, liabilities	311	159
Commodity derivative liabilities
Derivatives Fair Value [Line Items]
Gross Fair Value, Liabilities	5,269	123
Effect of Counterparty Netting, Liabilities	(531)	(105)
Total net carrying value on Balance Sheet, liabilities	$ 4,738	$ 18

Commodity Derivative Financia_5

Commodity Derivative Financial Instruments - Changes in Fair Value of Company's Commodity Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivatives not designated as hedging instruments
Gain (loss) on commodity derivative instruments	$ (19,174)	$ 29,187	$ 70,837	$ (11,996)
Net cash paid (received) on settlements of derivative instruments			(45,506)	(4,674)
Not Designated as Hedging Instrument
Derivatives not designated as hedging instruments
Beginning fair value of commodity derivative instruments	96,278	5,112	15,221	48,038
Net change in fair value of commodity derivative instruments	(55,726)	26,256	25,331	(16,670)
Ending fair value of commodity derivative instruments	40,552	31,368	40,552	31,368
Not Designated as Hedging Instrument | Oil
Derivatives not designated as hedging instruments
Gain (loss) on commodity derivative instruments	(21,647)	7,905	56,164	(31,356)
Net cash paid (received) on settlements of derivative instruments	(26,776)	1,745	(28,317)	(2,810)
Not Designated as Hedging Instrument | Natural gas and natural gas liquids sales
Derivatives not designated as hedging instruments
Gain (loss) on commodity derivative instruments	2,473	21,282	14,673	19,360
Net cash paid (received) on settlements of derivative instruments	$ (9,776)	$ (4,676)	$ (17,189)	$ (1,864)

Commodity Derivative Financia_6

Commodity Derivative Financial Instruments - Summary of Open Derivative Contracts for Oil and Natural Gas (Details) - Not Designated as Hedging Instrument bbl in Thousands, MMBTU in Thousands	6 Months Ended
	Jun. 30, 2020MMBTU$ / bbl$ / MMBTUbbl
Swaps Contract | Second Quarter 2020 | Oil | Swap
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	210
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu)	57.32
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	54.92
Derivative, Average Cap Price	58.65
Swaps Contract | Third Quarter 2020 | Oil | Swap
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	630
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu)	57.32
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	54.92
Derivative, Average Cap Price	58.65
Swaps Contract | Third Quarter 2020 | Natural gas and natural gas liquids sales | Swap
Derivative [Line Items]
Derivative Contract, Volume (in MMBtu) | MMBTU	10,120
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu) | $ / MMBTU	2.69
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu) | $ / MMBTU	2.55
Derivative, Average Cap Price | $ / MMBTU	2.74
Swaps Contract | Fourth Quarter 2020 | Oil | Swap
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	630
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu)	57.32
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	54.92
Derivative, Average Cap Price	58.65
Swaps Contract | Fourth Quarter 2020 | Natural gas and natural gas liquids sales | Swap
Derivative [Line Items]
Derivative Contract, Volume (in MMBtu) | MMBTU	10,120
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu) | $ / MMBTU	2.69
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu) | $ / MMBTU	2.55
Derivative, Average Cap Price | $ / MMBTU	2.74
Swaps Contract | First Quarter 2021 | Oil | Swap
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	480
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu)	36.18
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	32.64
Derivative, Average Cap Price	37.92
Swaps Contract | First Quarter 2021 | Natural gas and natural gas liquids sales | Swap
Derivative [Line Items]
Derivative Contract, Volume (in MMBtu) | MMBTU	7,200
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu) | $ / MMBTU	2.60
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu) | $ / MMBTU	2.52
Derivative, Average Cap Price | $ / MMBTU	2.72
Swaps Contract | Second Quarter 2021 | Oil | Swap
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	480
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu)	36.18
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	32.64
Derivative, Average Cap Price	37.92
Swaps Contract | Second Quarter 2021 | Natural gas and natural gas liquids sales | Swap
Derivative [Line Items]
Derivative Contract, Volume (in MMBtu) | MMBTU	7,280
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu) | $ / MMBTU	2.60
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu) | $ / MMBTU	2.52
Derivative, Average Cap Price | $ / MMBTU	2.72
Swaps Contract | Third Quarter 2021 | Oil | Swap
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	480
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu)	36.18
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	32.64
Derivative, Average Cap Price	37.92
Swaps Contract | Third Quarter 2021 | Natural gas and natural gas liquids sales | Swap
Derivative [Line Items]
Derivative Contract, Volume (in MMBtu) | MMBTU	7,360
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu) | $ / MMBTU	2.60
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu) | $ / MMBTU	2.52
Derivative, Average Cap Price | $ / MMBTU	2.72
Swaps Contract | Fourth Quarter 2021 | Oil | Swap
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	480
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu)	36.18
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	32.64
Derivative, Average Cap Price	37.92
Swaps Contract | Fourth Quarter 2021 | Natural gas and natural gas liquids sales | Swap
Derivative [Line Items]
Derivative Contract, Volume (in MMBtu) | MMBTU	7,360
Derivative Contract, Weighted Average Price (in USD per Bbl or MMBtu) | $ / MMBTU	2.60
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu) | $ / MMBTU	2.52
Derivative, Average Cap Price | $ / MMBTU	2.72
Collar Contract | Second Quarter 2020 | Oil | Collar
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	70
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	56.43
Derivative, Average Cap Price	67.14
Collar Contract | Third Quarter 2020 | Oil | Collar
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	210
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	56.43
Derivative, Average Cap Price	67.14
Collar Contract | Fourth Quarter 2020 | Oil | Collar
Derivative [Line Items]
Derivative Contract, Volume (in Bbl) | bbl	210
Derivative Contract, Price Range Low (in USD per Bbl or MMBtu)	56.43
Derivative, Average Cap Price	67.14

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	$ 49,868	$ 19,741
Effect of Counterparty Netting, Assets	(4,267)	(4,343)
Total net carrying value on Balance Sheet, assets	45,601	15,398
Gross Fair Value, Liabilities	9,316	4,520
Effect of Counterparty Netting, Liabilities	(4,267)	(4,343)
Total net carrying value on Balance Sheet, liabilities	5,049	177
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Effect of Counterparty Netting, Assets	(4,267)	(4,343)
Total net carrying value on Balance Sheet, assets	45,601	15,398
Effect of Counterparty Netting, Liabilities	(4,267)	(4,343)
Total net carrying value on Balance Sheet, liabilities	5,049	177
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	0	0
Gross Fair Value, Liabilities	0	0
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	49,868	19,741
Gross Fair Value, Liabilities	9,316	4,520
Commodity Derivative Instruments | Fair Value Measurements, Recurring Basis | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	0	0
Gross Fair Value, Liabilities	$ 0	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Assets and Liabilities Measured At Fair Value on a Nonrecurring Basis (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment of oil and natural gas properties	$ 0	$ 0	$ 51,031,000	$ 0
Fair Value Measurements, Nonrecurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment of oil and natural gas properties	$ 0	0	$ 51,031,000	0
Fair Value Measurements, Nonrecurring Basis | Measurement Input, Discount Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired property, plant and equipment, measurement input	8.00%		8.00%
Fair Value Measurements, Nonrecurring Basis | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired oil and natural gas properties	$ 0	0	$ 0	0
Fair Value Measurements, Nonrecurring Basis | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired oil and natural gas properties	0	0	0	0
Fair Value Measurements, Nonrecurring Basis | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired oil and natural gas properties	$ 0	$ 0	$ 0	$ 0	$ 2,044,000

Credit Facility (Details)

Credit Facility (Details)	Oct. 31, 2018	Jun. 30, 2020USD ($)	Jul. 21, 2020USD ($)assets	May 01, 2020USD ($)	Dec. 31, 2019USD ($)	Oct. 23, 2019USD ($)	Oct. 22, 2019USD ($)
Line Of Credit Facility [Line Items]
Credit facility		$ 323,000,000			$ 394,000,000
Subsequent Event
Line Of Credit Facility [Line Items]
Number of assets sold | assets			2
Senior Line of Credit | Revolving Credit Facility
Line Of Credit Facility [Line Items]
Maximum borrowing capacity		$ 1,000,000,000
Borrowing base				$ 460,000,000		$ 650,000,000	$ 675,000,000
Weighted average interest rate (percent)		2.43%			4.05%
Interest payable, term		90 days
Borrowing base threshold (percent)		50.00%
Credit facility		$ 323,000,000			$ 394,000,000
Unused portion of current borrowing base		$ 137,000,000			$ 256,000,000
Senior Line of Credit | Revolving Credit Facility | Subsequent Event
Line Of Credit Facility [Line Items]
Borrowing base			$ 430,000,000
Senior Line of Credit | Revolving Credit Facility | Federal Funds
Line Of Credit Facility [Line Items]
Interest rate (percent)		0.50%
Senior Line of Credit | Revolving Credit Facility | LIBOR Plus Margin Rate
Line Of Credit Facility [Line Items]
Interest rate (percent)		1.00%
Senior Line of Credit | Revolving Credit Facility | Borrowing Base Utilization Percentage Less Than 50%
Line Of Credit Facility [Line Items]
Commitment fee payable rate (percent)		0.375%
Senior Line of Credit | Revolving Credit Facility | Borrowing Base Utilization Percentage Equal to or Greater Than 50%
Line Of Credit Facility [Line Items]
Commitment fee payable rate (percent)		0.50%
Senior Line of Credit | Revolving Credit Facility | Minimum
Line Of Credit Facility [Line Items]
Interest payable, term		90 days
Current ratio		1
Senior Line of Credit | Revolving Credit Facility | Minimum | LIBOR Plus Margin Rate
Line Of Credit Facility [Line Items]
Interest rate (percent)	1.75%
Senior Line of Credit | Revolving Credit Facility | Minimum | Prime Rate Plus Margin Rate
Line Of Credit Facility [Line Items]
Interest rate (percent)	0.75%
Senior Line of Credit | Revolving Credit Facility | Maximum
Line Of Credit Facility [Line Items]
Ratio of total debt to EBITDAX		3.5
Senior Line of Credit | Revolving Credit Facility | Maximum | LIBOR Plus Margin Rate
Line Of Credit Facility [Line Items]
Interest rate (percent)	2.75%
Senior Line of Credit | Revolving Credit Facility | Maximum | Prime Rate Plus Margin Rate
Line Of Credit Facility [Line Items]
Interest rate (percent)	1.75%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	Jun. 30, 2020	Nov. 28, 2017
Comin
Business Acquisition [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	45.33%
Temin
Business Acquisition [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	42.63%
Samedan
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired		100.00%

Incentive Compensation - Summar

Incentive Compensation - Summary of Incentive Compensation Expense (Details) - General and administrative expenses - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash—short and long-term incentive plans	$ 506	$ 1,471	$ 1,469	$ 3,243
Incentive compensation expense	2,980	5,286	1,049	16,282
Restricted common and subordinated units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	1,126	2,591	2,411	5,610
Restricted Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	1,098	637	(3,559)	6,257
Common Units | Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive compensation expense	$ 250	$ 587	$ 728	$ 1,172

Redeemable Preferred Units (Det

Redeemable Preferred Units (Details) - Series B Cumulative Convertible Preferred Units - USD ($) $ / shares in Units, $ in Thousands	Nov. 28, 2017	Jun. 30, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Shares, price per share (in dollars per share)	$ 20.3926
Proceeds from issuance of convertible preferred stock	$ 300,000
Preferred units distribution rate		7.00%
Minimum underlying value for conversion trigger		$ 10,000
Preferred units, outstanding value		298,361	$ 298,361
Accrued distributions		$ 5,300	$ 5,300
Noble Acquisition
Class of Stock [Line Items]
Number of shares issued (in shares)	14,711,219

Earnings Per Unit - Computation

Earnings Per Unit - Computation of Basic and Diluted Earnings per Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share Basic [Line Items]
Net income (loss)	$ (8,371)	$ 95,087	$ 67,741	$ 104,104
Distributions on Series B cumulative convertible preferred units	(5,250)	(5,250)	(10,500)	(10,500)
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND COMMON AND SUBORDINATED UNITS	(13,621)	89,837	57,241	93,604
ALLOCATION OF NET INCOME (LOSS):
General partner interest	0	0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND COMMON AND SUBORDINATED UNITS	(13,621)	89,837	57,241	93,604
Common Units
ALLOCATION OF NET INCOME (LOSS):
Allocation of net income (loss)	$ (13,621)	$ 67,718	$ 57,241	$ 69,611
Weighted average common units outstanding:
Weighted average units outstanding (basic) (in shares)	206,707	150,101	206,669	129,873
Effect of dilutive securities (in shares)	0	14,969	0	0
Weighted average units outstanding (diluted) (in shares)	206,707	165,070	206,669	129,873
NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER COMMON AND SUBORDINATED UNIT:
Per unit (basic) (in dollars per share)	$ (0.07)	$ 0.45	$ 0.28	$ 0.54
Per unit (diluted) (in dollars per share)	$ (0.07)	$ 0.44	$ 0.28	$ 0.54
Subordinated units
ALLOCATION OF NET INCOME (LOSS):
Allocation of net income (loss)	$ 0	$ 22,119	$ 0	$ 23,993
Weighted average common units outstanding:
Weighted average units outstanding (basic) (in shares)	0	56,104	0	76,105
Effect of dilutive securities (in shares)	0	0	0	0
Weighted average units outstanding (diluted) (in shares)	0	56,104	0	76,105
NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER COMMON AND SUBORDINATED UNIT:
Per unit (basic) (in dollars per share)	$ 0	$ 0.39	$ 0	$ 0.32
Per unit (diluted) (in dollars per share)	$ 0	$ 0.39	$ 0	$ 0.32

Earnings Per Unit - Potentially

Earnings Per Unit - Potentially Dilutive Securities Excluded from the Computation of Diluted Weighted Average Shares Outstanding (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Series B cumulative convertible preferred units on an as-converted basis | Common Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Units issuable upon conversion of preferred units excluded from the calculation of diluted EPU (common units)	14,969	0	14,969	14,969

Common and Subordinated Units_2

Common and Subordinated Units (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Nov. 05, 2018
Class of Stock [Line Items]
Partners' capital account, distribution amount per share (in dollars per share)	$ 1.35
Stock repurchase program, authorized amount		$ 75,000,000
Series B Cumulative Convertible Preferred Units
Class of Stock [Line Items]
Preferred units minimum voting rights rate (percent)	15.00%
Preferred units distribution rate	7.00%
Common Units
Class of Stock [Line Items]
Treasury stock, value, acquired, cost method	$ 0
Common Units | November 2018 Repurchase Program
Class of Stock [Line Items]
Treasury stock, value, acquired, cost method	$ 4,200,000

Common and Subordinated Units -

Common and Subordinated Units - Per share distributions to common and subordinated unitholders (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Common Units
Class of Stock [Line Items]
Per unit (in usd per share)	$ 0.0800	$ 0.3700	$ 0.3800	$ 0.7400
Subordinated units
Class of Stock [Line Items]
Per unit (in usd per share)	$ 0	$ 0.3700	$ 0	$ 0.7400

Subsequent Events (Details)

Subsequent Events (Details)	Jul. 27, 2020$ / shares
Subsequent Event | Common Units
Subsequent Event [Line Items]
Quarterly cash distribution declared (in usd per unit)	$ 0.15