Document and Entity Information	9 Months Ended
Document and Entity Information	Sep. 30, 2015	Nov. 06, 2015 Common Units	Nov. 06, 2015 Subordinate Units	Nov. 06, 2015 Preferred Units
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Trading Symbol	BSM
Entity Registrant Name	Black Stone Minerals, L.P.
Entity Central Index Key	0001621434
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Partnership Units Outstanding		96,185,592	95,057,312	117,963

CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2015	Dec. 31, 2014
CURRENT ASSETS
Cash and cash equivalents	$ 5,570	$ 14,803
Accounts receivable	52,347	74,092
Commodity derivative assets	34,336	37,471
Prepaid expenses and other current assets	1,404	8,538
TOTAL CURRENT ASSETS	93,657	134,904
PROPERTY AND EQUIPMENT
Oil and natural gas properties, at cost, on the basis of the successful efforts method of accounting, includes unproved properties of $621,140 and $626,376 at September 30, 2015 and December 31, 2014, respectively	2,481,864	2,379,543
Accumulated depreciation, depletion and amortization, including impairment	(1,430,004)	(1,191,861)
Oil and natural gas properties, net	1,051,860	1,187,682
Other property and equipment, net of accumulated depreciation of $14,687 and $12,994 at September 30, 2015 and December 31, 2014, respectively	67	1,664
NET PROPERTY AND EQUIPMENT	1,051,927	1,189,346
DEFERRED CHARGES AND OTHER LONG-TERM ASSETS	15,862	2,532
TOTAL ASSETS	1,161,446	1,326,782
CURRENT LIABILITIES
Accounts payable	28,108	29,415
Accrued liabilities	18,227	16,252
TOTAL CURRENT LIABILITIES	46,335	98,572
LONG-TERM LIABILITIES
Credit facility	43,000	394,000
Accrued incentive compensation	8,401	6,530
Deferred revenue	3,333	3,917
Asset retirement obligations	10,181	9,381
TOTAL LIABILITIES	111,250	512,400
COMMITMENTS AND CONTINGENCIES (Note 7)
MEZZANINE EQUITY
Partners' equity - redeemable preferred units, 118 and 157 units outstanding at September 30, 2015 and December 31, 2014, respectively	120,936	161,165
EQUITY
Noncontrolling interests	2,308
TOTAL EQUITY	929,260	653,217
TOTAL LIABILITIES, MEZZANINE EQUITY AND EQUITY	1,161,446	1,326,782
Predecessor
CURRENT LIABILITIES
Accrued distribution payable to Predecessor unitholders		52,905
EQUITY
TOTAL EQUITY		653,217
Common Units
EQUITY
Partners' equity - limited partner units	621,796
Common Units \| Predecessor
EQUITY
Partners' equity - limited partner units		653,217
Subordinate Units
EQUITY
Partners' equity - limited partner units	$ 305,156

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2015	Dec. 31, 2014
Oil and natural gas properties, unproved property costs	$ 621,140	$ 626,376
Other property and equipment accumulated depreciation and amortization	$ 14,687	$ 12,994
Preferred Units
Partners' equity, preferred units, outstanding	117,963	157,203
Common Units
Partners' equity, limited partner units, outstanding	96,186,000	0
Common Units \| Predecessor
Partners' equity, limited partner units, outstanding	0	164,484,000
Subordinate Units
Partners' equity, limited partner units, outstanding	95,057,000	0

The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References+ Details

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
REVENUE
Oil and condensate sales	$ 44,128	$ 71,089	$ 126,584	$ 195,665
Natural gas and natural gas liquids sales	32,191	45,914	92,799	156,554
Gain on commodity derivative instruments	56,430	8,682	57,450	339
Lease bonus and other income	4,271	7,110	16,051	26,586
TOTAL REVENUE	137,020	132,795	292,884	379,144
OPERATING (INCOME) EXPENSE
Lease operating expense	4,924	6,037	16,540	15,707
Production costs and ad valorem taxes	8,175	12,181	26,250	33,589
Exploration expense	1,817	440	2,014	444
Depreciation, depletion and amortization	23,288	37,065	83,414	84,058
Impairment of oil and natural gas properties	24,854		156,683
General and administrative	18,994	15,644	53,530	45,607
Accretion of asset retirement obligations	265	148	805	443
(Gain) loss on sale of assets, net	4		(20)
TOTAL OPERATING EXPENSE	82,321	71,515	339,216	179,848
INCOME (LOSS) FROM OPERATIONS	54,699	61,280	(46,332)	199,296
OTHER INCOME (EXPENSE)
Interest and investment income	18	3	46	27
Interest expense	(870)	(3,440)	(5,530)	(10,292)
Other income	45	62	241	869
TOTAL OTHER EXPENSE	(807)	(3,375)	(5,243)	(9,396)
NET INCOME (LOSS)	53,892	57,905	(51,575)	189,900
NET (INCOME) LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS SUBSEQUENT TO INITIAL PUBLIC OFFERING	(3)		137
DISTRIBUTIONS ON PREFERRED UNITS SUBSEQUENT TO INITIAL PUBLIC OFFERING	(2,973)		(4,783)
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND LIMITED PARTNERS SUBSEQUENT TO INITIAL PUBLIC OFFERING	50,916		(56,671)
ALLOCATION OF NET INCOME (LOSS) SUBSEQUENT TO INITIAL PUBLIC OFFERING ATTRIBUTABLE TO:
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND LIMITED PARTNERS SUBSEQUENT TO INITIAL PUBLIC OFFERING	50,916		(56,671)
Predecessor
OTHER INCOME (EXPENSE)
NET INCOME (LOSS)		(57,905)	(450)	(189,900)
Common Units
ALLOCATION OF NET INCOME (LOSS) SUBSEQUENT TO INITIAL PUBLIC OFFERING ATTRIBUTABLE TO:
Limited partner interests	25,608		(28,502)
NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER UNIT:
Per limited partner unit (basic)	$ 0.27		$ (0.30)
Per limited partner unit (diluted)	$ 0.27		$ (0.30)
Weighted average limited partner units outstanding (basic and diluted)	96,186		96,183
DISTRIBUTIONS DECLARED AND PAID SUBSEQUENT TO INITIAL PUBLIC OFFERING:
Per limited partner unit	$ 0.1615		$ 0.1615
Subordinate Units
ALLOCATION OF NET INCOME (LOSS) SUBSEQUENT TO INITIAL PUBLIC OFFERING ATTRIBUTABLE TO:
Limited partner interests	$ 25,308		$ (28,169)
NET INCOME (LOSS) ATTRIBUTABLE TO LIMITED PARTNERS PER UNIT:
Per limited partner unit (basic)	$ 0.27		$ (0.30)
Per limited partner unit (diluted)	$ 0.27		$ (0.30)
Weighted average limited partner units outstanding (basic and diluted)	95,057		95,057
DISTRIBUTIONS DECLARED AND PAID SUBSEQUENT TO INITIAL PUBLIC OFFERING:
Per limited partner unit	$ 0.1615		$ 0.1615

CONSOLIDATED STATEMENT OF EQUITY (Unaudited) (USD $) In Thousands, except Share data	Total USD ($)	Predecessor USD ($)	Common Units	Common Units Predecessor	Subordinate Units	Partners Equity Common Units USD ($)	Partners Equity Subordinated Units USD ($)	Noncontrolling Interest USD ($)
Beginning balance at Dec. 31, 2014	$ 653,217	$ 653,217
Beginning balance, units at Dec. 31, 2014				164,484,000
Conversion of Predecessor redeemable preferred units	39,240	39,240
Conversion of Predecessor preferred units, units				2,750,000
Restricted common units granted			1,111,000	562,000
Repurchases of Predecessor units	(3,015)	(3,015)
Repurchases of Predecessor units, units				(164,000)
Distributions to Predecessor unitholders and noncontrolling interests	(73,205)	(73,205)
Distributions on Predecessor preferred units	(4,040)	(4,040)
Allocation of Predecessor units and partners' equity to common and subordinated units		(612,647)				264,235	345,875	2,537
Allocation of Predecessor units and partners' equity to common and subordinated units, units			72,575,000	(167,632,000)	95,057,000
Issuance of common units for initial public offering, net of offering costs	391,500					391,500
Issuance of common units for initial public offering, net of offering costs, units			22,500,000
Equity-based compensation	13,052					10,250	2,802
Distributions	(30,978)					(15,534)	(15,352)	(92)
Charges to Partners' equity for accrued distribution equivalent rights	(153)					(153)
Net income (loss)	(52,025)	450				(26,096)	(25,792)	(137)
Distributions on preferred units	(4,783)					(2,406)	(2,377)
Ending balance at Sep. 30, 2015	$ 929,260					$ 621,796	$ 305,156	$ 2,308
Ending balance, units at Sep. 30, 2015			96,186,000		95,057,000

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ (51,575)	$ 189,900
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	83,414	84,058
Impairment of oil and natural gas properties	156,683
Accretion of asset retirement obligations	805	443
Amortization of deferred charges	724	726
Gain on commodity derivative instruments	(57,450)	(339)
Net cash received (paid) on settlement of commodity derivative instruments	46,532	(3,369)
Equity-based compensation	13,052	7,452
Gain on sale of assets, net	(20)
Changes in operating assets and liabilities:
Accounts receivable	22,485	(133)
Prepaid expenses and other current assets	(453)	(4,178)
Accounts payable and accrued liabilities	3,674	6,373
Deferred revenue	(584)	(2,516)
Settlement of asset retirement obligations	(122)	(19)
NET CASH PROVIDED BY OPERATING ACTIVITIES	217,165	278,398
CASH FLOWS FROM INVESTING ACTIVITIES
Additions to oil and natural gas properties	(42,401)	(57,427)
Purchase of other property and equipment	(96)	(312)
Proceeds from the sale of oil and natural gas properties	432	10,625
Acquisitions of oil and natural gas properties	(62,157)	(45,431)
NET CASH USED IN INVESTING ACTIVITIES	(104,222)	(92,545)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of common units of Black Stone Minerals, L.P., net of offering costs	399,087
Distributions to noncontrolling interests	(167)
Net repayments under senior line of credit	(351,000)	(21,000)
Note receivable-officers		101
NET CASH USED IN FINANCING ACTIVITIES	(122,176)	(207,984)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(9,233)	(22,131)
CASH AND CASH EQUIVALENTS - beginning of the period	14,803	30,123
CASH AND CASH EQUIVALENTS - end of the period	5,570	7,992
SUPPLEMENTAL DISCLOSURE
Interest paid	4,794	9,721
NON-CASH ACTIVITIES
Conversion of redeemable preferred units	(39,240)	(221)
Accrued distributions payable for preferred units	(989)	(6)
Property additions and acquisitions financed through accounts payable and accrued liabilities	12,844	22,086
Public offering costs capitalized and offset against proceeds from initial public offering	7,587
Accrued distribution equivalent rights	153
Asset retirement obligations incurred	117	99
Liabilities assumed as consideration for oil and natural gas properties acquired		7,000
Acquisition of oil and natural gas properties financed through issuance of common units		2,258
Deferred revenue settled through acquisition of oil and natural gas properties		(2,657)
Predecessor
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	(450)	(189,900)
CASH FLOWS FROM FINANCING ACTIVITIES
Distributions to unitholders	(126,383)	(170,117)
Repurchases of Predecessor units	(3,015)	(5,199)
NON-CASH ACTIVITIES
Accrued Predecessor distributions payable	(53,248)	(1,155)
Common and Subordinated Units
CASH FLOWS FROM FINANCING ACTIVITIES
Distributions to unitholders	(30,886)
Preferred Units
CASH FLOWS FROM FINANCING ACTIVITIES
Distributions to unitholders	$ (9,812)	$ (11,769)

Business and Basis of Presentation	9 Months Ended
Business and Basis of Presentation	Sep. 30, 2015
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”) is a publicly traded Delaware limited partnership formed on September 16, 2014. On May 6, 2015, BSM completed its initial public offering (the “IPO”) of 22,500,000 common units representing limited partner interests at a price to the public of $19.00 per common unit. BSM received proceeds of $391.5 million from the sale of its common units, net of underwriting discount, structuring fee, and offering expenses (including costs previously incurred and capitalized). BSM used the net proceeds from the IPO to repay substantially all indebtedness outstanding under its credit facility. On May 1, 2015, BSM’s common units began trading on the New York Stock Exchange under the symbol “BSM.” Black Stone Minerals Company, L.P., a Delaware limited partnership, and its subsidiaries (collectively referred to as “BSMC” or the “Predecessor”) own oil and natural gas mineral interests in the United States. In connection with the IPO, BSMC was merged into a wholly owned subsidiary of BSM, with BSMC as the surviving entity. Pursuant to the merger, the Class A and Class B common units representing limited partner interests of the Predecessor were converted into an aggregate of 72,574,715 common units and 95,057,312 subordinated units of BSM at a conversion ratio of 12.9465:1 for 0.4329 common units and 0.5671 subordinated units, and the preferred units of BSMC were converted into an aggregate of 117,963 preferred units of BSM at a conversion ratio of one to one. The merger is accounted for as a combination of entities under common control with assets and liabilities transferred at their carrying amounts in a manner similar to a pooling of interests. Unless otherwise stated or the context otherwise indicates, all references to the “Company” or similar expressions for time periods prior to the IPO refer to Black Stone Minerals Company, L.P. and its subsidiaries, the Predecessor, for accounting purposes. For time periods subsequent to the IPO, these terms refer to Black Stone Minerals, L.P. and its subsidiaries. In addition to mineral interests, the Company’s assets include nonparticipating and overriding royalty interests. These non-cost-bearing interests are collectively referred to as “mineral and royalty interests.” As of September 30, 2015, the Company’s mineral and royalty interests are located in most of the major onshore oil and natural gas producing basins spread across 41 states and 62 onshore oil and natural gas producing basins of the continental U.S. The Company also owns non-operated working interests in certain oil and natural gas properties. Basis of presentation: The accompanying unaudited interim consolidated financial statements of the Company 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 U.S. GAAP. Accordingly, the accompanying unaudited interim consolidated financial statements and related notes should be read in conjunction with the Company’s annual consolidated financial statements and related notes included in its final prospectus (the “Prospectus”) dated April 30, 2015 and filed with the SEC, pursuant to Rule 424(b) under the Securities Act of 1933 (the “Securities Act”), on May 1, 2015. The financial statements include the consolidated results of the Company. BSM’s general partner, Black Stone Minerals GP, L.L.C., is a wholly owned subsidiary. All intercompany balances and transactions have been eliminated. Certain reclassifications have been made to the prior periods presented to conform to the current period financial statement presentation. The reclassifications have no effect on the consolidated financial position, results of operations, or cash flows of the Company. In the opinion of management, all material adjustments, which are of a normal and recurring nature, necessary for a fair presentation of the results for the periods presented have been reflected. The results of operations for the three and nine months ended September 30, 2015 are not necessarily indicative of the results to be expected for the full year. The Company evaluates the significant terms of its investments to determine the method of accounting to be applied to each respective investment. Investments in which the Company has less than a 20% ownership interest and does not have control or exercise significant influence are accounted for under the cost method. The Company’s cost method investment is included in deferred charges and other long-term assets in the consolidated balance sheets. Investments in which the Company exercises control are consolidated, and the noncontrolling interests of such investments, which are not attributable directly or indirectly to the Company, are presented as a separate component of net income and equity in the accompanying consolidated financial statements. The consolidated financial statements include undivided interests in oil and natural gas property rights. The Company 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 consolidated balance sheets, statements of operations, and statements of cash flows. Segment reporting: The Company 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 Company’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 Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2—SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant accounting policies: Our significant accounting policies are disclosed in Note 2 of the consolidated financial statements for the years ended December 31, 2014 and 2013 included in the Prospectus. There have been no changes in such policies or the application of such policies during the nine months ended September 30, 2015. New accounting pronouncements: In May 2014, the Financial Accounting Standards Board (the “FASB”) issued an accounting standards update on a comprehensive new revenue recognition standard that will supersede Accounting Standards Codification (“ASC”) 605, Revenue Recognition. The new accounting guidance creates a framework under which an entity will allocate the transaction price to separate performance obligations and recognize revenue when each performance obligation is satisfied. Under the new standard, entities will be required to use judgment and make estimates, including identifying performance obligations in a contract, estimating the amount of variable consideration to include in the transaction price, allocating the transaction price to each separate performance obligation, and determining when an entity satisfies its performance obligations. The standard allows for either “full retrospective” adoption, meaning that the standard is applied to all of the periods presented with a cumulative catch-up as of the earliest period presented, or “modified retrospective” adoption, meaning the standard is applied only to the most current period presented in the financial statements with a cumulative catch-up as of the current period. In July 2015, the FASB decided to defer the original effective date by one year to be effective for annual reporting periods beginning after December 15, 2017 instead of December 15, 2016 for public entities. The Company is still evaluating the impact that the new accounting guidance will have on its consolidated financial statements and related disclosures and has not yet determined the method by which it will adopt the standard. In April 2015, the FASB issued an accounting standards update that requires debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying value of that debt liability, consistent with debt discounts. The guidance is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted for financial statements that have not been previously issued. The Company does not expect the impact of adopting this guidance will be material to the Company’s consolidated financial statements and related disclosures. In April 2015, the FASB issued an accounting standards update that specifies that for purposes of calculating historical earnings per unit under the two-class method, the earnings (losses) of a transferred business before the date of a dropdown transaction should be allocated entirely to the general partner. In that circumstance, the previously reported earnings per unit of the limited partners (which is typically the earnings per unit measure presented in the financial statements) would not change as a result of the dropdown transaction. Qualitative disclosures about how the rights to the earnings (losses) differ before and after the dropdown transaction occurs for purposes of computing earnings per unit under the two-class method also are required. The guidance is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted. The Company does not expect the impact of adopting this guidance will be material to the Company’s consolidated financial statements and related disclosures. In September 2015, the FASB issued an accounting standards update that requires that adjustments to provisional amounts identified during the measurement period of a business combination be recognized in the reporting period in which those adjustments are determined, including the effect on earnings, if any, calculated as if the accounting had been completed at the acquisition date. This eliminates the previous requirement to retrospectively account for such adjustments. The new standard also requires additional disclosures related to the income statement effects of adjustments to provisional amounts identified during the measurement period. The guidance is effective for public companies during interim and annual reporting periods beginning after December 15, 2015. Early adoption is permitted. The Company does not expect the impact of adopting this guidance will be material to the Company’s consolidated financial statements and related disclosures.

- Definition

The entire disclosure for all significant accounting policies of the reporting entity.

+ References+ Details

Asset Retirement Obligations

9 Months Ended

Sep. 30, 2015

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

NOTE 3—ASSET RETIREMENT OBLIGATIONS

The asset retirement obligation (“ARO”) liability reflects the present value of estimated costs of dismantlement, removal, site reclamation, and similar activities associated with the Company’s working-interest oil and natural gas properties. The Company utilizes current retirement costs to estimate the expected cash outflows for retirement obligations. The Company estimates the ultimate productive life of its properties, a risk-adjusted discount rate, and an inflation factor in order to determine the current present value of this obligation. To the extent future revisions to these assumptions impact the present value of the existing ARO liability, a corresponding adjustment is made to the oil and natural gas property balance. The following table describes changes to the Company’s ARO liability during the period:

	For the nine months ended
	September 30, 2015
	(In thousands)
Beginning asset retirement obligations	$	9,381
Liabilities incurred		117
Liabilities settled		(122	)
Accretion expense		805
Ending asset retirement obligations	$	10,181

Derivatives and Financial Instruments

9 Months Ended

Sep. 30, 2015

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Derivatives and Financial Instruments

NOTE 4—DERIVATIVES AND FINANCIAL INSTRUMENTS

The Company’s ongoing operations expose it to changes in the market price for oil and natural gas. To mitigate these price fluctuations, the Company uses commodity derivative instruments. From time to time, such instruments may include fixed-price swaps, costless collars, fixed-price contracts, and other contractual arrangements. The Company does not enter into derivative instruments for speculative purposes.

A fixed-price-swap contract between the Company and the counterparty specifies a fixed commodity price and a future settlement date. The Company will receive from, or pay to, the counterparty the difference between the fixed swap price and the market price on the settlement date. Costless collars are a combination of a purchased put option and a sold call option, in which the premiums net to zero. With a costless collar, the counterparty is required to make a payment to the Company if the settlement price for any settlement period is below the exercise price of the purchased put. The Company is required to make a payment to the counterparty if the settlement price for any settlement period is above the exercise price for the sold call of the collar. The settlement paid or received is the difference between the market price on the settlement date and the related exercise price. All derivative instruments that have not yet been settled in cash are reflected as either derivative assets or liabilities in the Company’s accompanying consolidated balance sheets as of September 30, 2015 and December 31, 2014. See Note 5 – Fair Value Measurement for further discussion.

The table below summarizes the fair value and classification of the Company’s derivative instruments:

As of September 30, 2015
Classification	Balance Sheet Location	Gross Fair Value		Effect of Counterparty Netting		Net Carrying Value on Balance Sheet
				(In thousands)
Assets:
Current asset	Commodity derivative assets	$	34,336	$	—	$	34,336
Long-term asset	Deferred charges and other long-term assets		14,053		—		14,053
Total assets		$	48,389	$	—	$	48,389
Liabilities:
Current liability	Commodity derivative liabilities	$	—	$	—	$	—
Long-term liability	Commodity derivative liabilities		—		—		—
Total liabilities		$	—	$	—	$	—

As of December 31, 2014
Classification	Balance Sheet Location	Gross Fair Value		Effect of Counterparty Netting			Net Carrying Value on Balance Sheet
				(In thousands)
Assets:
Current asset	Commodity derivative assets	$	37,656	$	(185	)	$	37,471
Long-term asset	Deferred charges and other long-term assets		—		—			—
Total assets		$	37,656	$	(185	)	$	37,471
Liabilities:
Current liability	Commodity derivative liabilities	$	185	$	(185	)	$	—
Long-term liability	Commodity derivative liabilities		—		—			—
Total liabilities		$	185	$	(185	)	$	—

Changes in the fair values of the Company’s derivative instruments (both assets and liabilities) are presented on a net basis in the accompanying consolidated statements of operations. Changes in the fair value of the Company’s commodity derivative instruments (both assets and liabilities) are as follows:

	For the nine months ended September 30,
Derivatives not designated as hedging instruments under ASC 815	2015			2014
	(In thousands)
Beginning fair value of commodity derivative instruments	$	37,471		$	(1,812	)
Gain on oil derivative instruments		37,305			833
Gain (loss) on natural gas derivative instruments		20,145			(494	)
Net cash (received) paid on settlements of oil derivative instruments		(32,274	)		932
Net cash (received) paid on settlements of natural gas derivative instruments		(14,258	)		2,437
Net change in fair value of commodity derivative instruments		10,918			3,708
Ending fair value of commodity derivative instruments	$	48,389		$	1,896

The Company had the following open derivative contracts for oil as of September 30, 2015:

	Volume		Weighted Average		Range (Per Bbl)
Period and Type of Contract	(Bbl)		(Per Bbl)		Low		High
Oil Collars:
Q3 2015
Collar contracts:
Call Options		42,000	$	102.48	$	102.00	$	103.55
Put Options		42,000	$	84.76	$	84.00	$	85.00
Q4 2015
Collar contracts:
Call Options		30,000	$	102.00	$	102.00	$	102.00
Put Options		30,000	$	85.00	$	85.00	$	85.00
Oil Swaps:
Q3 2015
Swap contracts:		156,000	$	57.89	$	46.86	$	60.22
Q4 2015
Swap contracts:		531,000	$	59.19	$	47.39	$	61.71
2016
Swap contracts:		1,779,000	$	57.63	$	48.54	$	63.07
2017
Swap contracts:		703,000	$	58.50	$	52.73	$	63.65

The Company had the following open derivative contracts for natural gas as of September 30, 2015:

	Volume		Weighted Average		Range (Per MMBtu)
Period and Type of Contract	(MMBtu)		(Per MMBtu)		Low		High
Natural Gas Swaps:
Q4 2015
Swap contracts:		7,600,000	$	3.22	$	2.82	$	3.53
2016
Swap contracts:		24,250,000	$	3.18	$	3.00	$	3.41
2017
Swap contracts:		9,650,000	$	3.33	$	3.14	$	3.52

As of November 6, 2015, the Company has not entered into any additional derivative contracts for oil and natural gas.

Fair Value Measurement

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Fair Value Measurements

NOTE 5—FAIR VALUE MEASUREMENT

ASC 820, Fair Value Measurement, defines fair value as the amount at which an asset (or liability) could be sold (or transferred) in an orderly transaction between market participants at the measurement date. Further, ASC 820 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 Company’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 Company’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. There were no transfers into, or out of, the three levels of the fair value hierarchy for the nine months ended September 30, 2015 or the year ended December 31, 2014.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The Company 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 – Derivatives and Financial Instruments for further discussion.

The following table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis:

	Fair Value Measurements Using						Effect of Counterparty
	Level 1		Level 2		Level 3		Netting			Total
	(In thousands)
As of September 30, 2015
Financial Assets
Commodity derivative instruments	$	—	$	48,389	$	—	$	—		$	48,389
Financial Liabilities
Commodity derivative instruments		—		—		—		—		$	—
As of December 31, 2014
Financial Assets
Commodity derivative instruments	$	—	$	37,656	$	—	$	(185	)	$	37,471
Financial Liabilities
Commodity derivative instruments		—		185		—		(185	)	$	—

Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis

The determination of the fair values of proved and unproved properties acquired in purchase transactions are prepared by estimating discounted-cash-flow projections. The factors used to determine fair value include estimates of economic reserves, future operating and development costs, future commodity prices, and a market-based weighted-average cost of capital.

Oil and natural gas properties are measured at fair value on a nonrecurring basis using the income approach when measuring impairment. 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. Significant Level 3 assumptions used to determine fair value include estimates of proved reserves, future commodity prices, the timing and amount of future production and capital expenditures, and a discount rate commensurate with the risk associated with the respective oil and natural gas properties.

The Company’s estimates of fair value have been determined at discrete points in time based on relevant market data. These estimates involve uncertainty and cannot be determined with precision. There were no significant changes in valuation techniques or related inputs as of September 30, 2015 or December 31, 2014.

The following table presents information about the Company’s assets measured at fair value on a nonrecurring basis:

	Fair Value Measurements Using						Net Book
	Level 1		Level 2		Level 3		Value		Impairment
	(In thousands)
As of September 30, 2015
Impaired oil and natural gas properties	$	—	$	—	$	127,630	$	284,313	$	156,683
As of December 31, 2014
Impaired oil and natural gas properties	$	—	$	—	$	81,864	$	199,794	$	117,930

The estimated carrying value of all debt as of September 30, 2015 and December 31, 2014 approximated the fair value due to variable market rates of interest. These fair values, which are Level 3 measurements, were estimated based on the Company’s incremental borrowing rates for similar types of borrowing arrangements, when quoted market prices were not available. The estimated fair values of the Company’s financial instruments are not necessarily indicative of the amounts that would be realized in a current market exchange. The carrying value of receivables and payables approximate fair value due to the short-term nature of the instruments.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References+ Details

Related Party Transactions	9 Months Ended
Related Party Transactions	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 6—RELATED PARTY TRANSACTIONS The Predecessor executed promissory notes dated April 15, 2010, in the amount of $0.5 million to certain officers of the Predecessor. The promissory notes related to the acquisition of a partnership interest in a former affiliate by the officers, and the notes were collateralized by a security interest in the Predecessor. The aggregate outstanding note balance and interest receivable of $0.1 million was received during the nine months ended September 30, 2014.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References+ Details

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 7—COMMITMENTS AND CONTINGENCIES Environmental Matters The Company’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 Company 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 made. Litigation From time to time, the Company is involved in legal actions and claims arising in the ordinary course of business. The Company believes existing claims as of September 30, 2015 will be resolved without material adverse effect on the Company’s financial condition or operations.

- Definition

The entire disclosure for commitments and contingencies.

+ References+ Details

Credit Facility

9 Months Ended

Sep. 30, 2015

Debt Disclosure [Abstract]

Credit Facility

NOTE 8—CREDIT FACILITY

On January 23, 2015, the Company amended and restated its senior secured revolving credit agreement (the “Senior Line of Credit”). The Senior Line of Credit has a maximum credit amount of $1.0 billion. On October 28, 2015, the Senior Line of Credit was further amended to extend the term of the agreement from February 3, 2017 to February 4, 2019. The amount of the borrowing base is derived from the value of the Company’s oil and natural gas properties determined by the lender syndicate using pricing assumptions that often differ from strip prices. The borrowing base was $700.0 million at December 31, 2014. The Company’s semi-annual borrowing base redetermination process resulted in a decrease of the borrowing base to $600.0 million, effective April 10, 2015. Effective October 28, 2015, the borrowing base was further decreased to $550.0 million. Drawings on the Senior Line of Credit are used for the acquisition of oil and natural gas properties and for other general business purposes.

Borrowings under the Senior Line of Credit bear interest at LIBOR plus a margin between 1.50% and 2.50%, or prime rate plus a margin between 0.50% and 1.50%, with the margin depending on the borrowing base utilization percentage of the loan, as detailed in the table below. The prime rate is determined to be the higher of the financial institution’s prime rate or the federal funds effective rate plus 0.50% per annum. The weighted-average interest rate of the Senior Line of Credit was 1.94% and 2.41% as of September 30, 2015 and December 31, 2014, 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% per annum if the borrowing base utilization percentage is equal to or greater than 50%. The Senior Line of Credit is secured by a majority of the Company’s oil and natural gas production and assets.

	Borrowing Base Utilization
Borrowing type	<25%			³25% <50%			³50% <75%			³75% <90%			³90%
Eurodollar Margin		1.50	%		1.75	%		2.00	%		2.25	%		2.50	%
Base Rate Margin		0.50	%		0.75	%		1.00	%		1.25	%		1.50	%

The Senior Line of Credit contains various limitations on future borrowings, leases, hedging, and sales of assets. Additionally, the Senior Line of Credit requires the Company 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 September 30, 2015, the Company was in compliance with all financial covenants in the Senior Line of Credit.

The aggregate principal balance outstanding was $43.0 million and $394.0 million at September 30, 2015 and December 31, 2014, respectively. The unused portion of the available borrowings under the Senior Line of Credit was $557.0 million and $306.0 million at September 30, 2015 and December 31, 2014, respectively. Refer to Note 1 – Business and Basis of Presentation for a discussion of the use of proceeds from the IPO.

Incentive Compensation

9 Months Ended

Sep. 30, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Incentive Compensation

NOTE 9—INCENTIVE COMPENSATION

Effective May 6, 2015, the Company’s general partner adopted a long-term incentive plan (the “2015 LTIP”), pursuant to which non-employee directors of the Company’s general partner and certain employees and consultants of the Company and its affiliates are eligible to receive awards with respect to the Company’s common or subordinated units. In connection with the IPO, outstanding restricted common units in the Predecessor were exchanged for restricted common and subordinated units in the Company under the 2015 LTIP. Additionally, a provision contained in certain of the Predecessor’s restricted unit agreements that allowed award recipients to request cash settlement for up to 50% of their restricted unit awards granted prior to December 31, 2014 was removed; as such, these awards are no longer classified as liability awards. The Company’s general partner currently intends to grant new equity-based awards under the 2015 LTIP only with respect to common units. The 2015 LTIP permits the grant of unit options, unit appreciation rights, restricted units, unit awards, phantom units, distribution equivalent rights either in tandem with an award or as a separate award, cash awards, and other unit-based awards.

On May 6, 2015, in conjunction with the adoption of the 2015 LTIP, the Board of Directors of the Company’s general partner (the “Board”) approved a grant of awards to each of the Company’s executive officers, certain other employees, and each of the non-employee directors of the Company’s general partner. These awards consisted of restricted common units, restricted performance units (in the form of phantom units) with distribution equivalent rights, fully vested common units, and cash awards. The grants included 1,034,013 restricted common units subject to limitations on transferability, customary forfeiture provisions, and service-based graded vesting requirements through April 1, 2019. The holders of restricted common unit awards have all of the rights of a common unitholder, including non-forfeitable distribution rights with respect to their restricted common units. The grant-date fair value of these awards, net of estimated forfeitures, is recognized ratably using the straight-line attribution method. The Board also approved a grant of 947,142 restricted performance units that are subject to both performance-based and service-based vesting provisions. The number of common units issued to a recipient upon vesting of a restricted performance unit will be calculated based on performance against certain metrics that relate to the Company’s performance over each of the four 12-month performance periods commencing April 1, 2015. The target number of common units subject to each restricted performance unit is one; however, based on the achievement of performance criteria, the number of common units that may be received in settlement of each restricted performance unit can range from zero to two times the target number. The restricted performance units are eligible to become earned as follows: 16.66%, 16.67%, and 16.67% of the performance units may become earned in each of the 12-month performance periods that end on March 31, 2016, March 31, 2017, and March 31, 2018, respectively. The remaining 50% of the restricted performance units are eligible to become earned during the final 12-month performance period that ends on March 31, 2019. If the performance criteria are not met for the final performance period, the awards allow for a make-up period ending on March 31, 2020. Compensation expense related to the restricted performance unit awards is determined by multiplying the number of common units underlying such awards that, based on the Company’s estimate, are likely to vest, by the grant-date fair value and recognized using the accelerated attribution method. Distribution equivalent rights for the restricted performance unit awards that are expected to vest are charged to partners’ capital. Additionally, non-employee directors of the Company’s general partner received a one-time grant totaling 63,156 fully vested common units. Cash awards totaling $2.7 million with service-based graded vesting requirements through March 31, 2019 were also granted to certain other employees.

The table below summarizes incentive compensation expense recorded in general and administrative expenses in the consolidated statements of operations for the three and nine months ended September 30, 2015 and 2014, respectively.

	Three Months Ended September 30,				Nine Months Ended September 30,
Incentive compensation expense	2015		2014		2015		2014
	(In thousands)
Cash—long-term incentive plan	$	3,434	$	4,457	$	10,914	$	10,182
Equity-based compensation—restricted common and subordinated units		3,136		1,716		7,086		5,148
Equity-based compensation—restricted performance units		2,070		—		3,330		—
Board of Directors incentive plan		484		550		2,636		3,710
Total incentive compensation expense	$	9,124	$	6,723	$	23,966	$	19,040

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References+ Details

Redeemable Preferred Units	9 Months Ended
Redeemable Preferred Units	Sep. 30, 2015
Equity [Abstract]
Redeemable Preferred Units	NOTE 10—REDEEMABLE PREFERRED UNITS The Company has 117,963 and 157,203 preferred units outstanding with a carrying value of $120.9 million and $161.2 million as of September 30, 2015 and December 31, 2014, respectively. The aforementioned amounts include accrued distributions of $3.0 million and $4.0 million as of September 30, 2015 and December 31, 2014, respectively. The redeemable preferred units are classified as mezzanine equity on the consolidated balance sheets since redemption is outside the control of the Company. The preferred units are entitled to an annual distribution of 10% of the funded capital of the preferred units, payable on a quarterly basis in arrears. The preferred units are convertible into common and subordinated units at any time at the option of the preferred unitholders. The preferred units have an adjusted conversion price of $14.2683 and an adjusted conversion rate of 30.3431 common units and 39.7427 subordinated units per preferred unit, which reflects the reverse split described in Note 1 – Business and Basis of Presentation and the capital restructuring related to the IPO. The owners of the preferred units could elect to have the Company redeem up to 25% per year of their initial balance of preferred units at face value, plus any accrued and unpaid distributions, on December 31 of each year from 2014 to 2017. The Company shall have the right, at its sole option, to redeem an amount of preferred units equal to the units being redeemed by an owner of preferred units on each December 31. Any amount of a given year’s 25% of preferred units not redeemed on December 31 shall automatically convert to common and subordinated units on January 1 of the following year. For the nine months ended September 30, 2015, 39,240 preferred units totaling $39.2 million were converted into the equivalent of 1,190,664 common units and 1,559,502 subordinated units on an adjusted basis, which included units automatically converted on January 1, 2015.

Earnings Per Unit

9 Months Ended

Sep. 30, 2015

Earnings Per Share [Abstract]

Earnings Per Unit

NOTE 11—EARNINGS PER UNIT

The Company applies the two-class method for purposes of calculating earnings per unit (“EPU”). The holders of the Company’s restricted common and subordinated units have all the rights of a unitholder, including non-forfeitable distribution rights. As participating securities, the restricted common and subordinated 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 Company is allocated to our 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 redeemable preferred units could be converted into 3.6 million common units and 4.7 million subordinated units as of September 30, 2015, and 4.8 million common units and 6.2 million subordinated units, on an adjusted basis, as of September 30, 2014. At September 30, 2015 and 2014, if the redeemable preferred units were converted to common and subordinated units, the effect would be anti-dilutive. Therefore, the redeemable preferred units are not included in the diluted EPU calculation. The Company’s restricted performance unit awards are contingently issuable units that are considered in the calculation of diluted EPU. The Company 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. As of September 30, 2015, there were no units related to the Company’s restricted performance unit awards included in the calculation of diluted EPU.

The following table sets forth the computation of basic and diluted earnings per common and subordinated unit:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(In thousands, except per unit amounts)
Net income (loss)	$	53,892		$	57,905		$	(51,575	)	$	189,900
Net income attributable to Predecessor		—			(57,905	)		(450	)		(189,900	)
Net (income) loss attributable to noncontrolling interests subsequent to initial public offering		(3	)		—			137			—
Distributions on preferred units subsequent to initial public offering		(2,973	)		—			(4,783	)		—
Net income (loss) attributable to the general partner and limited partners subsequent to initial public offering	$	50,916		$	—		$	(56,671	)	$	—
Allocation of net income (loss) subsequent to initial public offering attributable to:
General partner interest	$	—					$	—
Common limited partner interests		25,608						(28,502	)
Subordinated limited partner interests		25,308						(28,169	)
	$	50,916					$	(56,671	)
Net income (loss) attributable to limited partners per unit:
Per common limited partner unit (basic and diluted)	$	0.27					$	(0.30	)
Weighted average common limited partner units outstanding (basic and diluted)		96,186						96,183
Per subordinated limited partner unit (basic and diluted)	$	0.27					$	(0.30	)
Weighted average subordinated limited partner units outstanding (basic and diluted)		95,057						95,057

- Definition

The entire disclosure for earnings per share.

+ References+ Details

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	BLACK STONE MINERALS, L.P. NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Unaudited) NOTE 12—SUBSEQUENT EVENTS On October 20, 2015, the Company announced its intention to commence a cash tender offer to purchase up to 100% of the 117,963 outstanding preferred units from its preferred unitholders at the units’ par value of $1,000.00 per preferred unit, plus unpaid accrued yield. The Company intends to fund the tender offer with cash on hand and funds available under its revolving credit facility. BSM commenced the proposed tender offer on November 6, 2015. The proposed tender offer will expire on December 10, 2015. On October 28, 2015, the Company received a cash payment of $18.7 million from an operator to terminate an exploration and development agreement related to certain mineral and leasehold interests owned by the Company. On November 9, 2015, the Board approved a distribution for the period July 1, 2015 through September 30, 2015 of $0.2625 per unit for common and subordinated unitholders. Distributions will be payable on November 27, 2015 to unitholders of record at the close of business on November 19, 2015.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2015
Accounting Policies [Abstract]
New Accounting Pronouncements	New accounting pronouncements: In May 2014, the Financial Accounting Standards Board (the “FASB”) issued an accounting standards update on a comprehensive new revenue recognition standard that will supersede Accounting Standards Codification (“ASC”) 605, Revenue Recognition. The new accounting guidance creates a framework under which an entity will allocate the transaction price to separate performance obligations and recognize revenue when each performance obligation is satisfied. Under the new standard, entities will be required to use judgment and make estimates, including identifying performance obligations in a contract, estimating the amount of variable consideration to include in the transaction price, allocating the transaction price to each separate performance obligation, and determining when an entity satisfies its performance obligations. The standard allows for either “full retrospective” adoption, meaning that the standard is applied to all of the periods presented with a cumulative catch-up as of the earliest period presented, or “modified retrospective” adoption, meaning the standard is applied only to the most current period presented in the financial statements with a cumulative catch-up as of the current period. In July 2015, the FASB decided to defer the original effective date by one year to be effective for annual reporting periods beginning after December 15, 2017 instead of December 15, 2016 for public entities. The Company is still evaluating the impact that the new accounting guidance will have on its consolidated financial statements and related disclosures and has not yet determined the method by which it will adopt the standard. In April 2015, the FASB issued an accounting standards update that requires debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying value of that debt liability, consistent with debt discounts. The guidance is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted for financial statements that have not been previously issued. The Company does not expect the impact of adopting this guidance will be material to the Company’s consolidated financial statements and related disclosures. In April 2015, the FASB issued an accounting standards update that specifies that for purposes of calculating historical earnings per unit under the two-class method, the earnings (losses) of a transferred business before the date of a dropdown transaction should be allocated entirely to the general partner. In that circumstance, the previously reported earnings per unit of the limited partners (which is typically the earnings per unit measure presented in the financial statements) would not change as a result of the dropdown transaction. Qualitative disclosures about how the rights to the earnings (losses) differ before and after the dropdown transaction occurs for purposes of computing earnings per unit under the two-class method also are required. The guidance is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted. The Company does not expect the impact of adopting this guidance will be material to the Company’s consolidated financial statements and related disclosures. In September 2015, the FASB issued an accounting standards update that requires that adjustments to provisional amounts identified during the measurement period of a business combination be recognized in the reporting period in which those adjustments are determined, including the effect on earnings, if any, calculated as if the accounting had been completed at the acquisition date. This eliminates the previous requirement to retrospectively account for such adjustments. The new standard also requires additional disclosures related to the income statement effects of adjustments to provisional amounts identified during the measurement period. The guidance is effective for public companies during interim and annual reporting periods beginning after December 15, 2015. Early adoption is permitted. The Company does not expect the impact of adopting this guidance will be material to the Company’s consolidated financial statements and related disclosures.

Asset Retirement Obligations (Tables)

9 Months Ended

Sep. 30, 2015

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Change in Asset Retirement Obligation Liability

The following table describes changes to the Company’s ARO liability during the period:

	For the nine months ended
	September 30, 2015
	(In thousands)
Beginning asset retirement obligations	$	9,381
Liabilities incurred		117
Liabilities settled		(122	)
Accretion expense		805
Ending asset retirement obligations	$	10,181

Derivatives and Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2015

Derivative [Line Items]

Summary of Fair Value and Classification of Derivative Instruments

The table below summarizes the fair value and classification of the Company’s derivative instruments:

As of September 30, 2015
Classification	Balance Sheet Location	Gross Fair Value		Effect of Counterparty Netting		Net Carrying Value on Balance Sheet
				(In thousands)
Assets:
Current asset	Commodity derivative assets	$	34,336	$	—	$	34,336
Long-term asset	Deferred charges and other long-term assets		14,053		—		14,053
Total assets		$	48,389	$	—	$	48,389
Liabilities:
Current liability	Commodity derivative liabilities	$	—	$	—	$	—
Long-term liability	Commodity derivative liabilities		—		—		—
Total liabilities		$	—	$	—	$	—

As of December 31, 2014
Classification	Balance Sheet Location	Gross Fair Value		Effect of Counterparty Netting			Net Carrying Value on Balance Sheet
				(In thousands)
Assets:
Current asset	Commodity derivative assets	$	37,656	$	(185	)	$	37,471
Long-term asset	Deferred charges and other long-term assets		—		—			—
Total assets		$	37,656	$	(185	)	$	37,471
Liabilities:
Current liability	Commodity derivative liabilities	$	185	$	(185	)	$	—
Long-term liability	Commodity derivative liabilities		—		—			—
Total liabilities		$	185	$	(185	)	$	—

Changes in Fair Value of Company's Commodity Derivative Instruments

Changes in the fair value of the Company’s commodity derivative instruments (both assets and liabilities) are as follows:

	For the nine months ended September 30,
Derivatives not designated as hedging instruments under ASC 815	2015			2014
	(In thousands)
Beginning fair value of commodity derivative instruments	$	37,471		$	(1,812	)
Gain on oil derivative instruments		37,305			833
Gain (loss) on natural gas derivative instruments		20,145			(494	)
Net cash (received) paid on settlements of oil derivative instruments		(32,274	)		932
Net cash (received) paid on settlements of natural gas derivative instruments		(14,258	)		2,437
Net change in fair value of commodity derivative instruments		10,918			3,708
Ending fair value of commodity derivative instruments	$	48,389		$	1,896

Oil and Natural Gas

Derivative [Line Items]

Summary of Open Derivative Contracts

The Company had the following open derivative contracts for oil as of September 30, 2015:

	Volume		Weighted Average		Range (Per Bbl)
Period and Type of Contract	(Bbl)		(Per Bbl)		Low		High
Oil Collars:
Q3 2015
Collar contracts:
Call Options		42,000	$	102.48	$	102.00	$	103.55
Put Options		42,000	$	84.76	$	84.00	$	85.00
Q4 2015
Collar contracts:
Call Options		30,000	$	102.00	$	102.00	$	102.00
Put Options		30,000	$	85.00	$	85.00	$	85.00
Oil Swaps:
Q3 2015
Swap contracts:		156,000	$	57.89	$	46.86	$	60.22
Q4 2015
Swap contracts:		531,000	$	59.19	$	47.39	$	61.71
2016
Swap contracts:		1,779,000	$	57.63	$	48.54	$	63.07
2017
Swap contracts:		703,000	$	58.50	$	52.73	$	63.65

The Company had the following open derivative contracts for natural gas as of September 30, 2015:

	Volume		Weighted Average		Range (Per MMBtu)
Period and Type of Contract	(MMBtu)		(Per MMBtu)		Low		High
Natural Gas Swaps:
Q4 2015
Swap contracts:		7,600,000	$	3.22	$	2.82	$	3.53
2016
Swap contracts:		24,250,000	$	3.18	$	3.00	$	3.41
2017
Swap contracts:		9,650,000	$	3.33	$	3.14	$	3.52

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

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-Name Accounting Standards Codification

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+ Details

Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis:

	Fair Value Measurements Using						Effect of Counterparty
	Level 1		Level 2		Level 3		Netting			Total
	(In thousands)
As of September 30, 2015
Financial Assets
Commodity derivative instruments	$	—	$	48,389	$	—	$	—		$	48,389
Financial Liabilities
Commodity derivative instruments		—		—		—		—		$	—
As of December 31, 2014
Financial Assets
Commodity derivative instruments	$	—	$	37,656	$	—	$	(185	)	$	37,471
Financial Liabilities
Commodity derivative instruments		—		185		—		(185	)	$	—

Schedule of Assets Measured at Fair Value on a Nonrecurring Basis

The following table presents information about the Company’s assets measured at fair value on a nonrecurring basis:

	Fair Value Measurements Using						Net Book
	Level 1		Level 2		Level 3		Value		Impairment
	(In thousands)
As of September 30, 2015
Impaired oil and natural gas properties	$	—	$	—	$	127,630	$	284,313	$	156,683
As of December 31, 2014
Impaired oil and natural gas properties	$	—	$	—	$	81,864	$	199,794	$	117,930

Credit Facility (Tables)

9 Months Ended

Sep. 30, 2015

Debt Disclosure [Abstract]

Borrowing Base Utilization

The Senior Line of Credit is secured by a majority of the Company’s oil and natural gas production and assets.

	Borrowing Base Utilization
Borrowing type	<25%			³25% <50%			³50% <75%			³75% <90%			³90%
Eurodollar Margin		1.50	%		1.75	%		2.00	%		2.25	%		2.50	%
Base Rate Margin		0.50	%		0.75	%		1.00	%		1.25	%		1.50	%

Incentive Compensation (Tables)

9 Months Ended

Sep. 30, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Incentive Compensation Expense

	Three Months Ended September 30,				Nine Months Ended September 30,
Incentive compensation expense	2015		2014		2015		2014
	(In thousands)
Cash—long-term incentive plan	$	3,434	$	4,457	$	10,914	$	10,182
Equity-based compensation—restricted common and subordinated units		3,136		1,716		7,086		5,148
Equity-based compensation—restricted performance units		2,070		—		3,330		—
Board of Directors incentive plan		484		550		2,636		3,710
Total incentive compensation expense	$	9,124	$	6,723	$	23,966	$	19,040

Earnings Per Unit (Tables)

9 Months Ended

Sep. 30, 2015

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 September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(In thousands, except per unit amounts)
Net income (loss)	$	53,892		$	57,905		$	(51,575	)	$	189,900
Net income attributable to Predecessor		—			(57,905	)		(450	)		(189,900	)
Net (income) loss attributable to noncontrolling interests subsequent to initial public offering		(3	)		—			137			—
Distributions on preferred units subsequent to initial public offering		(2,973	)		—			(4,783	)		—
Net income (loss) attributable to the general partner and limited partners subsequent to initial public offering	$	50,916		$	—		$	(56,671	)	$	—
Allocation of net income (loss) subsequent to initial public offering attributable to:
General partner interest	$	—					$	—
Common limited partner interests		25,608						(28,502	)
Subordinated limited partner interests		25,308						(28,169	)
	$	50,916					$	(56,671	)
Net income (loss) attributable to limited partners per unit:
Per common limited partner unit (basic and diluted)	$	0.27					$	(0.30	)
Weighted average common limited partner units outstanding (basic and diluted)		96,186						96,183
Per subordinated limited partner unit (basic and diluted)	$	0.27					$	(0.30	)
Weighted average subordinated limited partner units outstanding (basic and diluted)		95,057						95,057

Business and Basis of Presentation - Additional Information (Details) (USD $) In Millions, except Share data, unless otherwise specified			9 Months Ended	0 Months Ended
	Sep. 30, 2015	Sep. 30, 2015 U.S. States Basins	Sep. 30, 2015 Common Units	May 06, 2015 Common Units Predecessor	May 06, 2015 Common Units IPO Limited Partner	May 06, 2015 Subordinate Units Predecessor	May 06, 2015 Preferred Units Predecessor
Limited Partners Capital Account [Line Items]
Issuance of common units for initial public offering, net of offering costs, units			22,500,000		22,500,000
Price per common unit (in dollars per unit)					$ 19.00
Proceeds from sale of common units, net of offering expenses and underwriting discounts and commissions					$ 391.5
Units exchanged in merger				72,574,715		95,057,312	117,963
Units conversion ratio as part of merger				12.9465		12.9465	1
Units conversion ratio split up as part of merger				0.4329		0.5671
Number of states major onshore oil and natural gas basins located		41
Number of onshore oil and natural gas producing basins		62
Cost basis, ownership percentage	20.00%

Asset Retirement Obligations - Schedule of Change in Asset Retirement Obligation Liability (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]
Beginning asset retirement obligations			$ 9,381
Liabilities incurred			117	99
Liabilities settled			(122)
Accretion expense	265	148	805	443
Ending asset retirement obligations	$ 10,181		$ 10,181

Derivatives and Financial Instruments - Summary of Fair Value and Classification of Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2015	Dec. 31, 2014
Derivatives Fair Value [Line Items]
Gross Fair Value, Assets	$ 48,389	$ 37,656
Effect of Counterparty Netting, Assets		(185)
Net Carrying Value on Balance Sheet, Assets	48,389	37,471
Gross Fair Value, Liabilities		185
Effect of Counterparty Netting, Liabilities		(185)
Commodity Derivative Assets, Current
Derivatives Fair Value [Line Items]
Gross Fair Value, Assets	34,336	37,656
Effect of Counterparty Netting, Assets		(185)
Net Carrying Value on Balance Sheet, Assets	34,336	37,471
Deferred Charges and Other Long-term Assets
Derivatives Fair Value [Line Items]
Gross Fair Value, Assets	14,053
Net Carrying Value on Balance Sheet, Assets	14,053
Commodity Derivative Liabilities, Current
Derivatives Fair Value [Line Items]
Gross Fair Value, Liabilities		185
Effect of Counterparty Netting, Liabilities		$ (185)

- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References+ Details

- Definition

Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References+ Details

- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References+ Details

Derivatives and Financial Instruments - Changes in Fair Value of Company's Commodity Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative [Line Items]
Gain (loss) on commodity derivative instruments	$ 56,430	$ 8,682	$ 57,450	$ 339
Net cash (received) paid on settlements of derivative instruments			(46,532)	3,369
Not Designated as Hedging Instrument
Derivative [Line Items]
Beginning fair value of commodity derivative instruments			37,471	(1,812)
Net change in fair value of commodity derivative instruments			10,918	3,708
Ending fair value of commodity derivative instruments	48,389	1,896	48,389	1,896
Oil \| Not Designated as Hedging Instrument
Derivative [Line Items]
Gain (loss) on commodity derivative instruments			37,305	833
Net cash (received) paid on settlements of derivative instruments			(32,274)	932
Natural Gas \| Not Designated as Hedging Instrument
Derivative [Line Items]
Gain (loss) on commodity derivative instruments			20,145	(494)
Net cash (received) paid on settlements of derivative instruments			$ (14,258)	$ 2,437

Derivatives and Financial Instruments - Summary of Open Derivative Contracts for Oil and Natural Gas (Details) (Not Designated as Hedging Instrument)	9 Months Ended
	Sep. 30, 2015 bbl
Oil \| Q3 2015 \| 2015 Collar Contracts \| Call Options
Derivative [Line Items]
Derivative Contract, Volume	42,000
Derivative Contract, Weighted Average Price	102.48
Derivative Contract, Price Range Low	102.00
Derivative Contract, Price Range High	103.55
Oil \| Q3 2015 \| 2015 Collar Contracts \| Put Options
Derivative [Line Items]
Derivative Contract, Volume	42,000
Derivative Contract, Weighted Average Price	84.76
Derivative Contract, Price Range Low	84.00
Derivative Contract, Price Range High	85.00
Oil \| Q3 2015 \| Swap Contracts \| Swap
Derivative [Line Items]
Derivative Contract, Volume	156,000
Derivative Contract, Weighted Average Price	57.89
Derivative Contract, Price Range Low	46.86
Derivative Contract, Price Range High	60.22
Oil \| Q4 2015 \| 2015 Collar Contracts \| Call Options
Derivative [Line Items]
Derivative Contract, Volume	30,000
Derivative Contract, Weighted Average Price	102.00
Derivative Contract, Price Range Low	102.00
Derivative Contract, Price Range High	102.00
Oil \| Q4 2015 \| 2015 Collar Contracts \| Put Options
Derivative [Line Items]
Derivative Contract, Volume	30,000
Derivative Contract, Weighted Average Price	85.00
Derivative Contract, Price Range Low	85.00
Derivative Contract, Price Range High	85.00
Oil \| Q4 2015 \| Swap Contracts \| Swap
Derivative [Line Items]
Derivative Contract, Volume	531,000
Derivative Contract, Weighted Average Price	59.19
Derivative Contract, Price Range Low	47.39
Derivative Contract, Price Range High	61.71
Oil \| 2016 \| Swap Contracts \| Swap
Derivative [Line Items]
Derivative Contract, Volume	1,779,000
Derivative Contract, Weighted Average Price	57.63
Derivative Contract, Price Range Low	48.54
Derivative Contract, Price Range High	63.07
Oil \| 2017 \| Swap Contracts \| Swap
Derivative [Line Items]
Derivative Contract, Volume	703,000
Derivative Contract, Weighted Average Price	58.50
Derivative Contract, Price Range Low	52.73
Derivative Contract, Price Range High	63.65
Natural Gas \| Q4 2015 \| Swap Contracts \| Swap
Derivative [Line Items]
Derivative Contract, Volume	7,600,000
Derivative Contract, Weighted Average Price	3.22
Derivative Contract, Price Range Low	2.82
Derivative Contract, Price Range High	3.53
Natural Gas \| 2016 \| Swap Contracts \| Swap
Derivative [Line Items]
Derivative Contract, Volume	24,250,000
Derivative Contract, Weighted Average Price	3.18
Derivative Contract, Price Range Low	3.00
Derivative Contract, Price Range High	3.41
Natural Gas \| 2017 \| Swap Contracts \| Swap
Derivative [Line Items]
Derivative Contract, Volume	9,650,000
Derivative Contract, Weighted Average Price	3.33
Derivative Contract, Price Range Low	3.14
Derivative Contract, Price Range High	3.52

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross Fair Value, Assets	$ 48,389	$ 37,656
Effect of Counterparty Netting, Assets		(185)
Net Carrying Value on Balance Sheet, Assets	48,389	37,471
Gross Fair Value, Liabilities		185
Effect of Counterparty Netting, Liabilities		(185)
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	48,389	37,656
Effect of Counterparty Netting, Assets		(185)
Net Carrying Value on Balance Sheet, Assets	48,389	37,471
Gross Fair Value, Liabilities		185
Effect of Counterparty Netting, Liabilities		$ (185)

- Definition

+ References+ Details

- Definition

+ References+ Details

- Definition

+ References+ Details

Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Nonrecurring Basis (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2015 Fair Value Measurements, Nonrecurring Basis	Dec. 31, 2014 Fair Value Measurements, Nonrecurring Basis	Sep. 30, 2015 Fair Value Measurements, Nonrecurring Basis Level 3	Dec. 31, 2014 Fair Value Measurements, Nonrecurring Basis Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Impaired oil and natural gas properties, Fair Value Measurements					$ 127,630	$ 81,864
Impaired oil and natural gas properties, Net Book Value			284,313	199,794
Impaired oil and natural gas properties, Impairment	$ 24,854	$ 156,683	$ 156,683	$ 117,930

Related Party Transactions - Additional Information (Details) (Predecessor, Officer, USD $) In Millions, unless otherwise specified	0 Months Ended
	Apr. 15, 2010	Sep. 30, 2014
Predecessor \| Officer
Related Party Transaction [Line Items]
Promissory note, executed amount	$ 0.5
Promissory notes receivable		$ 0.1

Commitments and Contingencies - Additional Information (Details) (USD $)	Sep. 30, 2015
Commitments And Contingencies Disclosure [Abstract]
Provision for remediation costs	$ 0

Credit Facility - Additional Information (Details) (USD $)			9 Months Ended			9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2015 Senior Line of Credit	Apr. 10, 2015 Senior Line of Credit	Dec. 31, 2014 Senior Line of Credit	Sep. 30, 2015 Senior Line of Credit Minimum	Sep. 30, 2015 Senior Line of Credit Maximum	Sep. 30, 2015 Senior Line of Credit LIBOR Plus Margin Rate Minimum	Sep. 30, 2015 Senior Line of Credit LIBOR Plus Margin Rate Maximum	Sep. 30, 2015 Senior Line of Credit Prime Rate Plus Margin Rate Minimum	Sep. 30, 2015 Senior Line of Credit Prime Rate Plus Margin Rate Maximum	Sep. 30, 2015 Senior Line of Credit Federal funds effective rate	Sep. 30, 2015 Senior Line of Credit Borrowing Base Utilization Percentage Less Than 50%	Sep. 30, 2015 Senior Line of Credit Borrowing Base Utilization Percentage Equal to or Greater Than 50%	Oct. 28, 2015 Senior Line of Credit Subsequent Event
Line Of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity			$ 1,000,000,000
Line of credit, borrowing base				600,000,000	700,000,000										550,000,000
Line of credit facility, expiration date			Feb. 04, 2019
Line of credit, interest rate								1.50%	2.50%	0.50%	1.50%	0.50%
Line of credit, prime rate description			The prime rate is determined to be the higher of the financial institution’s prime rate or the federal funds effective rate plus 0.50% per annum
Line of credit, weighted average interest rate			1.94%		2.41%
Line of credit, accrued interest periodic payments			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.
Line of credit facility, frequency of commitment fee payment			Commitment fee is payable at the end of each calendar
Line of credit, commitment fee payable rate													0.375%	0.50%
Line of credit, current ratio						100.00%
Line of credit, ratio of total debt to EBITDAX							350.00%
Credit facilities	43,000,000	394,000,000	43,000,000		394,000,000
Line of credit, unused portion of current borrowing base			$ 557,000,000		$ 306,000,000

Credit Facility - Borrowing Base Utilization (Details)	9 Months Ended
Credit Facility - Borrowing Base Utilization (Details)	Sep. 30, 2015
Borrowing Base Utilization Less Than25 Percent \| Eurodollar Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	1.50%
Borrowing Base Utilization Less Than25 Percent \| Base Rate Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	0.50%
Borrowing Base Utilization Percentage Greater Than Equal To25 Percent But Less Than50 Percent \| Eurodollar Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	1.75%
Borrowing Base Utilization Percentage Greater Than Equal To25 Percent But Less Than50 Percent \| Base Rate Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	0.75%
Borrowing Base Utilization Percentage Greater Than Equal To50 Percent But Less Than75 Percent \| Eurodollar Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	2.00%
Borrowing Base Utilization Percentage Greater Than Equal To50 Percent But Less Than75 Percent \| Base Rate Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	1.00%
Borrowing Base Utilization Percentage Greater Than Equal To75 Percent But Less Than90 Percent \| Eurodollar Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	2.25%
Borrowing Base Utilization Percentage Greater Than Equal To75 Percent But Less Than90 Percent \| Base Rate Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	1.25%
Borrowing Base Utilization Range Equal To Above90 Percent \| Eurodollar Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	2.50%
Borrowing Base Utilization Range Equal To Above90 Percent \| Base Rate Margin
Line Of Credit Facility [Line Items]
Line of credit, interest rate	1.50%

Incentive Compensation - Additional Information (Details) (2015 LTIP, USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended
	May 06, 2015
Other Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash awards granted	$ 2.7
Restricted Common Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant of stock units	1,034,013
Restricted Performance Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant of stock units	947,142
Target number of common units, Minimum	0
Target number of common units, Maximum	2
Restricted Performance Units \| March 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of restricted performance units are eligible to become earned	16.66%
Restricted Performance Units \| March 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of restricted performance units are eligible to become earned	16.67%
Restricted Performance Units \| March 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of restricted performance units are eligible to become earned	16.67%
Restricted Performance Units \| March 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of restricted performance units are eligible to become earned	50.00%
Common Units \| Non-employee Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant of stock units, fully vested	63,156
Predecessor \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash settlement of restricted unit awards granted	50.00%

Incentive Compensation - Summary of Incentive Compensation Expense (Details) (2015 LTIP, General and administrative expenses, USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash—long-term incentive plan	$ 3,434	$ 4,457	$ 10,914	$ 10,182
Total incentive compensation expense	9,124	6,723	23,966	19,040
Restricted common and subordinated units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	3,136	1,716	7,086	5,148
Restricted Performance Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity-based compensation	2,070		3,330
Board of Director \| Common Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total incentive compensation expense	$ 484	$ 550	$ 2,636	$ 3,710

Redeemable Preferred Units - Additional Information (Details) (USD $)	0 Months Ended	9 Months Ended
	Jan. 02, 2015	Sep. 30, 2015	Dec. 31, 2014
Class Of Stock [Line Items]
Preferred units, outstanding value		$ 120,936,000	$ 161,165,000
Preferred Units
Class Of Stock [Line Items]
Partners' equity, preferred units, outstanding		117,963	157,203
Preferred units, outstanding value		120,900,000	161,200,000
Accrued distributions		3,000,000	4,000,000
Preferred units distribution rate		10.00%
Adjusted conversion price		$ 14.2683
Preferred units, redemption terms		The owners of the preferred units could elect to have the Company redeem up to 25% per year of their initial balance of preferred units at face value, plus any accrued and unpaid distributions, on December 31 of each year from 2014 to 2017. The Company shall have the right, at its sole option, to redeem an amount of preferred units equal to the units being redeemed by an owner of preferred units on each December 31. Any amount of a given year’s 25% of preferred units not redeemed on December 31 shall automatically convert to common and subordinated units on January 1 of the following year.
Redemption percentage		25.00%
Preferred units redemption period start date		Dec. 31, 2014
Preferred units redemption period end date		Dec. 31, 2017
Number of preferred units converted	39,240	39,240
Conversion of preferred units to common units	$ 39,200,000	$ 39,200,000
Common Units
Class Of Stock [Line Items]
Adjusted conversion rate		30.3431
Conversion of preferred units	1,190,664	1,190,664
Subordinate Units
Class Of Stock [Line Items]
Adjusted conversion rate		39.7427
Conversion of preferred units	1,559,502	1,559,502

Earnings Per Unit - Additional Information (Details)	9 Months Ended
Earnings Per Unit - Additional Information (Details)	Sep. 30, 2015	Sep. 30, 2014
Restricted Performance Units
Earnings Per Share Basic [Line Items]
Number of performance units award included in calculation of diluted EPU	0
Common Units
Earnings Per Share Basic [Line Items]
Units issuable upon conversion of preferred units excluded from the calculation of diluted EPU	3,600,000	4,800,000
Subordinate Units
Earnings Per Share Basic [Line Items]
Units issuable upon conversion of preferred units excluded from the calculation of diluted EPU	4,700,000	6,200,000

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References+ Details

Earnings Per Unit - Computation of Basic and Diluted Earnings per Unit (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share Basic [Line Items]
Net income (loss)	$ 53,892	$ 57,905	$ (51,575)	$ 189,900
NET (INCOME) LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS SUBSEQUENT TO INITIAL PUBLIC OFFERING	(3)		137
DISTRIBUTIONS ON PREFERRED UNITS SUBSEQUENT TO INITIAL PUBLIC OFFERING	(2,973)		(4,783)
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND LIMITED PARTNERS SUBSEQUENT TO INITIAL PUBLIC OFFERING	50,916		(56,671)
Allocation of net income (loss) subsequent to initial public offering attributable to:
NET INCOME (LOSS) ATTRIBUTABLE TO THE GENERAL PARTNER AND LIMITED PARTNERS SUBSEQUENT TO INITIAL PUBLIC OFFERING	50,916		(56,671)
Common Units
Allocation of net income (loss) subsequent to initial public offering attributable to:
Limited partner interests	25,608		(28,502)
Net income (loss) attributable to limited partners per unit:
Per limited partner unit (basic)	$ 0.27		$ (0.30)
Per limited partner unit (diluted)	$ 0.27		$ (0.30)
Weighted average limited partner units outstanding (basic and diluted)	96,186		96,183
Subordinate Units
Allocation of net income (loss) subsequent to initial public offering attributable to:
Limited partner interests	25,308		(28,169)
Net income (loss) attributable to limited partners per unit:
Per limited partner unit (basic)	$ 0.27		$ (0.30)
Per limited partner unit (diluted)	$ 0.27		$ (0.30)
Weighted average limited partner units outstanding (basic and diluted)	95,057		95,057
Predecessor
Earnings Per Share Basic [Line Items]
Net income (loss)		$ (57,905)	$ (450)	$ (189,900)

Subsequent Events - Additional Information (Details) (USD $) In Millions, except Share data, unless otherwise specified			0 Months Ended
	Sep. 30, 2015 Preferred Units	Dec. 31, 2014 Preferred Units	Nov. 09, 2015 Subsequent Event	Oct. 28, 2015 Subsequent Event	Nov. 09, 2015 Subsequent Event Common Units	Nov. 09, 2015 Subsequent Event Subordinate Units	Oct. 20, 2015 Subsequent Event Preferred Units
Subsequent Event [Line Items]
Maximum percentage of preferred units repurchase							100.00%
Partners' equity, preferred units, outstanding	117,963	157,203					117,963
Partners' equity, preferred units, par value							$ 1,000
Proposed tender, offer date							Nov. 06, 2015
Proposed tender, offer expiration date							Dec. 10, 2015
Exploration and development agreement termination payment received				$ 18.7
Distribution declaration date			Nov. 09, 2015
Distribution date of record			Nov. 19, 2015
Distribution date			Nov. 27, 2015
Quarterly cash distribution declared					$ 0.2625	$ 0.2625